Naptha Cracking Plant Operation

SECTION MODULE NO.

RELIANCE INDUSTRIES LIMITED

CKR-PR-P-001

PROCESS DESCRIPTION AND

UTILITIES

CKR-PR-P-011

CHECKED BY PAGE 1 N.S.P Process description and Utilities REV 0

ISSUE 0APPROVED BY DATE 07/04/2023

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Preface

This operating manual gives general guidelines for the

understanding and operation of the Cracker Plant. It provides

basic information on the process , utilities, effluent treatment

and emergencies. This shall be read with other Standard

Operating Procedures to understand precisely the operation

and control methodology of the plant.

It is recognised that several improvements can be made to this

manual for more efficient operation of the plant. Any such

changes shall be communicated to the Manager in charge for

proper updating and revision.

Author

B.M.Krishna



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CONTENTS:

1 NGL / NAPHTHA CRACKER PLANT AT RIL, HAZIRA

1.1 Introduction

1.2 Feed Stock

1.3 Other Products

1.4 Chemicals, Additives And Catalysts

1.5 Products Specification

2 Process Description

2.01 Cracking Furnaces

2.02 USC main furnace and recycle furnace quench fittings

2.03 Quench Oil Tower

2.04 HFO Stripper

2.05 LFO Stripper

2.06 Quench Water Tower

2.07 Dilution Steam generation system

2.08 Distillate stripper

2.09 Quench Water Circulation Circuit

2.10 Quench Oil Circulation Circuit

2.11 Pan Oil Circulation Circuit

2.12 Cracked gas compression ,Acid gas removal,

Dehydration

2.13 Demethaniser system

2.14 PSA Unit

2.15 Deethaniser

2.16 C2 Acetylene hydrogenation system



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2.17 Ethylene fractionation

2.18 Depropaniser

2.19 C3 MAPD hydrogenation system

2.20 Secondary and tertiary deethanisers

2.21 Propylene fractionation

2.22 Debutaniser

2.23 C4 hydrogenation and Aux. C4 hydrogenation

2.24 Ethylene refrigeration system

2.25 Propylene Refrigeration System

2.26 Gasoline Hydrogenation Unit

2.27 Spent Caustic Oxidation Unit

3 Utilities

3.1 CW System

3.2 Steam System

3.3 Condensate and Boiler feed water system

3.4 Fuel gas system

3.5 Nitrogen, plant air, instrument air system

3.6 Service Water system

3.7 DM Water system

3.8 Fire water system

3.9 Electrical Power systems

4.0 Plant Effluents and disposal Methods

4.1 Liquid effluents

4.2 Solid effluents

4.3 Gaseous effluents

5 Emergencies



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5.1 Power failure (ISBL ONLY)

5.2 Steam failure

5.3 IA failure

5.4 CW failure

5.5 QW failure

5.6 QO failure

6 Equipment List

7

7.1 Relief and blowdown system

7.2 Flare system at OSBL

8.0 Fire and Gas Detection System



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1RELIANCE INDUSTRIES LIMITED

CKR-PR-P-001

1.1 INTRODUCTION

The NGL / Naphtha Cracker plant is designed to product

5,00,000 metric tonnes per annum of polymer grade ethylene

from cracking Naphtha and NGL. Subsequently, the plant was

engineered to increase the capacity from 5,00,000 MTA to

7,00,000 MTA.

It is designed to crack Naphtha, NGL, AGO and C2/C3 recycle

and fresh streams. However, the 7,00,000 MTA capacity of

ethylene is produced by cracking of low aromatics naphtha

only. Also, the recycle streams like C2,C3,C5, C6-C8 raffinate

from aromatics plant and hydrogenated mix C4 are cocracked

with Naphtha in the furnaces.

The minimum propylene production capacity is 3,20,000 MTA

for an optimum cracking severity of 3.11 KSFA for the designed

on stream time of 8000 hours per year.

The plant is able to produce HP ethylene vapour at

58kg/cm2g ,LP vapour ethylene at 27 kg/cm2g. and ethylene as

liquid at -980C for storage in atmospheric tank.

The plant also includes two IFP units C4 hydrogenation unit for

processing mixed C4 and GHU unit for the treatment of

gasoline generated during cracking. For the production of high

purity hydrogen, one PSA unit is installed supplied by UOP,

USA.



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1.2 FEED STOCKS

The cracker plant is designed on the basis of single light

naphtha feed stock as defined below :

SG : 0.7

Distribution Curve : 0C

1BP : 45

10% : 68

50% : 100

90% : 130

FBP : 150

PONA : WT

Paraffins 74% Min.

Naphthalenes Balance

Aromatic 10%

Olefins Vol. Max. 1.0%

Hydrogen, WT% 15.2

Sulphur PPM wt/wt 800 max.

RVP kg/cm2a 0.94 max.

However, plant is capable in using other feed stacks

NGL/AGO,C2/C3, recycle hydrogenated C4 mix, C5 from GHU

and C6-C8 raffinates from aromatics.



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DESIGN SPECIFICATION OF NGL FEEDSTOCK:

Particulars Unit Design

Specific Gravity - 0.73

ASTM distillation:

IBP C 45

50% C 95

FBP C 150

PONA analysis:

Paraffins vol. % 59

Naphthenes vol. % 26

Aromatic vol. 15

Olefins vol. nil

Sulphur ppm wt/wt 800

Reid Vapour

pressure

kg/cm2a 0.5

Lead ppm wt/wt 0.075

Chloride ppm wt/wt 2

Colour Saybolt

Note :

The i-Paraffins may be present up to 50% by wt. of total

Paraffins



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DESIGN SPECIFICATION OF C2/C3 FEEDSTOCK:

Components

Colour

Units Design

Methane % mol 0.7

Ethane % mol 75.54

Propane % mol 21.96

Butanes % mol 1.5

DESIGN SPECIFICATION OF C3/C4 FEEDSTOCK:

Components Units Design

Ethane % mol 0.98%

Propane % mol 49.02%

n-Butane % mol 34.31%

i-Butane % mol 14.71%

Pentane % mol 0.98%

1.3 Other Products:

While main products form cracker plant are ethylene and

propylene, there are a number of lesser products. These are

listed below :

Methane:

The plant is able to produce 500 kg/hr of methane vapour at 27

kg/cm2g and ambient temperature. It is intended to be used as

ballast gas MEG plants



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Hydrogen:

The high purity hydrogen produced form PSA unit is intended

for captive use for Acetylene, MAPD , C4 mix and gasoline

hydrogenations. The excess hydrogen is exported to OSBL for

use in aromatics, PTA & PE Plants.

Fuel Oil:

The fuel oil component product during liquid feed stocks are

rich in carbon index. This can be used as feestock for carbon

block manufacture.



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Ethane & Propane:

The ethane and propane produced form ethylene and

propylene fractionation system is cracked in recycle furnaces

or along with Naphtha in four main furnaces. Excess of ethane

and propane after vaporisation can be dumped in to fuel gas.

Also provision for export of ethane /propane mix is also

provided. However, liquid propane from propylene fractionation

system is preferentially exported to OSBL for storage to act as

back up fuel during emergency (or) during start-up of the plant.

C5 Mix.:

C5 Mixture reported from gasoline in depentaniser unit after

hydrogenation of diolefins impurities is recycled to furnace for

cracking along with Naphtha.

C6-C8 Cut :

C6-C8 after treatment in gasoline hydrogenation unit for the

improvement of stability, octane no. Bromine number and

sulphur is fed as feedstock for aromatics plant for the

separation of benzene, toluene and xylene.

Fuel Gas :



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Fuel Gas which is a mix of primarily methane and hydrogen is

fed to furnaces for providing heat for cracking. The excess of

the requirement is sent to OSBL for use in fuel in gas turbines,

dowtherm heaters, VCM furnaces etc.

Hydrogenated C4 Mix :

Butadiene rich C4 mix from liquid cracking is hydrogenated in

main and aux. C4 hydrogenation units to remove butadiene to

extinction is sent to OSBL to the sold as industrial LPG (or)

excess of the maker is cracked in main furnaces along with

Naphtha.

1.4 Chemicals, Catalysts and additives:

1.4.1 Chemicals:

Many chemicals are used at different parts of the plant for the

smooth and efficient of the plant. They are listed as below :

1) Ammonia

i) Deaerator (V900)

ii) QW Tower O/H (C-220)

2) Caustic (20%)

i) Dilution steam stripper (not used)

ii) Condensate polishing unit for regeneration

iii) Caustic tower

3) HCL (20%)

i) Condensate polishing unit for regeneration

ii) SCO effluent neutralisation



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4) DMDS

i) USC main furnaces with Naphtha

ii) USC recycle furnaces with Dilution steam

5) Hydrazine

i) Deaerator

6) Trisodium Phosphate

i) Main & Recycle furnace steam drums

7) Methanol

i) As required in cold sections

8) Corrosion inhibitor DP 1800

i) Process water stripper - C260

9) Antifoulant DORF 94362

I) Depropaniser C-510

10) Emulsion Breaker DORF EB 4024

i) C-220 quench water tower

11) Neutralising Amine DP 197

i) C-220 Quench water tower

12) Antioxidant DORF 410

i) Raw pyrolysis gasoline feed

ii) C5 product

iii) C9 product

iv) Raw C6-C8 cut

13) Corrosion Inhibitor DORF 2002 CI

i) GHU Stripper

14) Antipolymerant (Trial on)

i) Caustic tower



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1.4.2 Catalysts and Desiccants:

Unit Item No. Type Source1 Cracked Gas

DehydratorV 370 A/B Molecular sieve

EPG 118” and Alumina Balls

UOP

2 Secondary dehydrator

V 453 A/B Molecular sieve EPG 1/8 “ and Alumina Balls

UOP

3 C2 Acetylene hydrogenation

R-451 A/B/C R-452 A/B

G 58 E Catalysts and Alumina Balls

SUD CHEMIE UCIL

4 C3 MAPD Hydrogenation

R-531 A/B/C LD 273 catalyst and Alumina Balls

Procatalyse

5 C4 Main and auxiliary hydrogenation FIRST stage

R-801, R-803 LD 265 & Alumina Balls

Procatalyse

6 C4 Main & Auxiliary hydrogenation II stage

R-802, R-804 LD 271 & Alumina Balls

Procatalyse

7 Gasoline hydrogenation I stage

R-710 A/B LD 265 & Alumina Balls

Procatalyse

8 Gasoline hydrogenation II stage

R-740 LD 145 for upper bed and ALUMINA balls 1+R 306C and alumina balls for lower bed

Procatalyse

1.5 Product specifications:

SPECIFICATION OF POLYMER GRADE ETHYLENE PRODUCT:

Components Units Guaranteed Values

Expected

Ethylene % mol 99.95 min

Methane + Ethane ppm mol/mol 500 max 40 max



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Expected

C3 and Heavier ppm mol/mol 10 max

Other Olefins ppm mol/mol 10 max

Acetylene ppm mol/mol 5 max

Propadiene ppm mol/mol 5 max

Hydrogen ppm mol/mol 10 max

CO ppm mol/mol 0.2 max

CO2 ppm mol/mol 5 max

Oxygen ppm mol/mol 5 max

Nitrogen ppm mol/mol 50 max

NO ppm mol/mol 5 max

Ammonia ppm mol/mol 5 max

Carbon Oxysulphide ppm mol/mol 0.02 max

Sulphur ppm wt/wt 1 max

Water ppm wt/wt 1 max

Methanol ppm mol/mol 5 max

Chlorides ppm mol/mol 2 max

Acetone ppm mol/mol 2 max

Methylacetylene ppm mol/mol 5 max

Arsine ppm wt/wt 0.03 max

Carbonyl ppm mol/mol 5 max



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SPECIFICATION OF POLYMER GRADE PROPYLENE PRODUCT:


Propylene % mol 99.8 min

Ethane ppm mol/mol 30 max

Ethylene ppm mol/mol 10 max

Propane ppm mol/mol Balance

C4 and Heavier ppm mol/mol 2 max (as C4s)


Butenes ppm mol/mol 2 max

Butadiene ppm mol/mol 2 max

Methyl acetylene plus

Propadiene ppm mol/mol 10 max

Hydrogen ppm mol/mol 20 max

CO ppm mol/mol 0.05 max



Ammonia ppm wt/wt 5 max

Carbon Oxysulphide ppm mol/mol 0.02 max

Other Non condensibles ppm mol/mol 300 max

Sulphur ppm wt/wt 1 max

Water ppm wt/wt 2 max

Methanol ppm mol/mol 5 max

Green Oil ppm mol/mol

Arsine ppm wt/wt 0.03 max

Phosphine ppm wt/wt 0.03 max

Isopropanol ppm mol/mol 35 max



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SPECIFICATION OF HYDROGEN PRODUCT:


Hydrogen % mol 99.9 min

CO ppm mol/mol 5 max


Ammonia ppm mol/mol 1 max

Mercury mg/m3 1 max


Total Sulphur ppm wt/wt 0.5 max

Water mg/m3 5 max

CH4s, C2H6s H2

Argon

Balance


SPECIFICATION OF METHANE PRODUCT:


Methane % mol 95.0 min

Ethylene % mol 1.0 max

Hydrogen % mol 3.0 max

Carbon Monoxide % mol 1.0 max

Acetylene ppm

mol/mol

50 (1) max



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SPECIFICATION OF C4 STREAMS:

A. Mixed C4 Stream (before hydrogenation):

Expected Value

C3s and Ligher 0.15% wt max

C9s 0.4% wt max

1, 3-Butadiene 52% wt min and 56% wt max

B. Hydrogenated C4 Stream

Butadiene 10 ppm wt max

Dimer (C8) content: 500 ppm max

Trimer (Green Oil) content: none

SPECIFICATION OF C5 PRODUCT (PARTIALLY

HYDROGENATED):

Components Units Values

Distillate Residue % wt 1.5

C9s and lighter % mol Balance

C6s % mol 1.2% max

Benzene % mol 0.3% max

Diene value 2 max

Copper Strip Corrosion 1B

Existing Gum mg/100ml after

heptane wash

4 max

SPECIFICATION OF HYDROGENATED C6/C8 CUT:



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Components Units Values

C9s % mol

C9s-2000C % mol

C6-C8 Balance

Total Sulphur ppm wt 1.0 max

Bromine number gr/100 gr 0.1

Thiophene ‘S’ ppm wt 0.5 max

Copper Strip Corrosion IA

Diene Valve Nil

Existing Gum mg/100 ml after

heptane wash

Distillate Residue % 1.5 max (ASTM D-

62)

Oxidation Stability Minutes 960 min with 5

ppm antioxidant



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SPECIFICATION OF PYROLYSIS FUEL OIL:

PARTICULARS UNITS

LFO HFO PFO

Asphaltene % wt <0.2 30-50 15-20

Ramsbottom

Carbon

% wt <0.5 20-50 10-15(1)

Ash % wt <0.05 <0.05 <0.05

Sulfur % wt <0.09 <0.09 <0.09

Sodium ppm wt <10 <10 <10(2)

BMCI 125 >125 >125

Flash Pt deg C 90-100 >100 >100

Pour Pt deg C <0.0 >50.0 >15.0

NOTES :

1. Typical values are quoted

2. Based on no sodium being present in the plant feeds.



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2 RELIANCE INDUSTRIES LIMITED

CKR-PR-P-001

PROCESS DESCRIPTION



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2.00 PROCESS DESCRIPTION:

This section contains a description of the process flow during

normal operation with the RIL “Expansion Case” FEEDSTOCK.

The description should be read in conjunction with process flow

diagrams 0320015-75D-01 to 10.

2.01 CRACKING FURNACES

A total of 15 cracking furnaces are provided to achieve the

required annual ethylene and propylene production.

Twelve of these furnaces, H-110 t0 H-190 and H-192, 194 and

196, described as USC (ultra selective conversion) furnaces are

utilised to crack liquid naphtha fresh feed and H-110 to H-190

for Naphtha and AGO both and the liquid recycle streams

generated within the plant or from the aromatics unit i.e.

hydrogenated C4s, hydrogenated C5s and C6-C8 raffinate.

The remaining three furnaces, H-111, H-121 and H-131

described as USC recycle furnaces are installed to crack

gaseous ethane and propane feedstocks which are recovered

and recycled from the recovery section. Four of the USC

furnaces H-110, 120,130 and 140, can be utilised for ethane /

propane co-cracking with naphtha while one of the USC recycle

furnaces is being decocked.



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The naphtha feedstock is stored in OSBL, tanks and pumped to

the battery limit at 10.5 kg/cm2g. Hydrogenated C5’s and C6-

C8 raffinate for recycle cracking can also be supplied from

OSBL storage as C5-C87 max naphtha fresh feed line. The total

flow of C5-C8’s blended into the Naphtha is regulated. The

naphtha liquid blend is preheated by exchange with circulating

quench water in the Naphtha feed Heater, E-041. Hydrogenated

C4’s for recycle cracking can be obtained from storage or

directly from the hydrogenation units. A separate hydrogenated

C4’s header is provided and the flow to each fresh feed furnace

can be independently controlled. The hydrogenated C4’s are

blended with the Naphtha upstream of the furnace convection

section. The combined Naphtha liquid blend is fed through the

USC furnace convection section and partly vaporised. Dilution

steam is added downstream to the hydrocarbon feed stream to

complete vaporisation. A weight ratio of 0.5 steam to

hydrocarbon is utilised.

The liquid hydrocarbon feed is divided equally into six streams

before being fed to the USC furnace convection section. the

hydrocarbon fed is preheated by the furnace flue gas in the

fifth from bottom bank of the six-bank convection section.

Slightly superheated dilution steam form the Dilution Steam

Stripper, C-270, overhead and from the auxiliary dilution

steam stripper, C-80 overhead is split into six streams and fed



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to the dilution steam superheating coils located in the second

from bottom bank of convection section.

Three streams from each of the hydrocarbon and dilution

steam coils are combined into one and mixed in a sparger to

complete the vaporisation of hydrocarbon. There are two

spargers per furnace. One outlet is taken from each sparger

and split into three streams. The six streams of hydrocarbon

and dilution steam mixture are further heated in the fourth and

then first bank of the convection section. Three streams of

heated hydrocarbon and dilution steam mixture at the outlet of

the first bank are combined into one mixing fitting. There are

tow mixing fittings per furnace. Four outlets are taken from

each mixing fitting, and each outlet is split into eight radiant

coils. Each radiant coil is fitted with a critical flow venturi

nozzle.

The boiler feed water from the Deaerator is preheated in the

sixth (top) bank of the USC Furnace convection section and fed

to the steam drums, V-110 to 190, 192, 194 and 196. The

saturated steam generated in USX and TLX exchangers is

superheated in the third bank of the convection section.

The recycle ethane feed to the USC Recycle Furnaces is

vaporised by heat exchange against demethanizer feed, in E-

461, and heated against propylene refrigerant, in E-411, while

recycle propane feed is vaporised against circulating quench CHECKED BY PAGE 24

N.S.P Process description and Utilities REV 0ISSUE 0

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water in E-542. The ethane and propane is mixed and further

heated against circulating quench water, in E-011, before being

fed to the USC recycle furnaces. Dilution steam is added in a

weight ratio of 0.3 steam/hydrocarbon.

The ethane and propane mixed feed is split into four streams

before being fed to the USC Recycle Furnace Convection

section. The mixed hydrocarbon feed is preheated by the

furnace flue gas in the fourth (top) bank of the four-bank

convection section.

Slightly superheated steam from the dilution steam generator

is injected into each hydrocarbon stream at the outlet of the

fourth bank. The four mixed streams are further heated in the

first (hottest) bank of the convection section. Two streams of

the heated hydrocarbon and dilution steam mixture are

combined at the outlet of the first bank into one mixing fitting.

There are two mixing fittings per recycle furnace. Two outlets

are taken from each mixing fitting, and each feeds a separate

radiant coil. Each radiant coil is fitted with a critical flow venturi

Nozzle.

The boiler feedwater form the deaerator is preheated in the

third bank of the USC Recycle Furnace convection section and

fed to the steam Drums, V-111,121 and 131. The saturated

steam generated in USX exchangers is superheated in the

second bank of the convection section.CHECKED BY PAGE 25



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Both types of furnaces are vertical radiant tube type; the USC

Furnace employs 64 “U” coils with inlet and outlet at the top of

the radiant box. The USC recycle furnace employs four “M”

type radiant coils with inlet and outlet also at the top of the

radiant box.

The USC Furnaces each have 32 floor fired burners. The

burners are designed for gas firing only.

The USC Recycle Furnaces have both wall and floor burners.

Both floor and wall burners are gas fired. There are 16 floor

fired burners and 32 wall burners per furnace.

The feedstocks are thermally cracked in the furnaces where

dilution steam to feed ratios and furnace effluent temperature

are carefully controlled to achieve the desired olefin

distribution and yield. The furnace effluents are cooled rapidly

by heat exchange against boiler feed water in steam

generating USX exchangers, E-110 to 190, 192,194 and 196 A-

H & J-Q, and E-115/125/135 A-D, and TLX Exchangers, E-111 to

191, 193,195 and 197. Rapid quenching of the furnace effluent

is necessary to prevent degradation of olefins into undesirable

components. The high pressure steam generated in USX and

TLX exchangers is superheated in the convection section

before being used, mainly for compressor turbine drivers.



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2.02 USC Fresh feed and Recycle Furnace Quench

Fittings

The Quench Fittings, Z-110 to 190 and Z-192, 194 and 196, on

the USC fresh feed furnaces and Z-111/121 on the USC Recycle

Furnaces are provided to reduce the temperature of the

furnace effluent before entering the quench oil tower, C-210

and Heavy Fuel Oil Stripper, C-230, respectively. H-131 effluent

enters C-210 board on material balm to requirement . The

temperature reduction, or quenching, is achieved by contacting

individual furnace effluent streams with quench oil in specially

designed fittings.

2.03 Quench Oil Tower

The Quench Oil Tower, C-210 condenses the fuel oil

components and recovers higher level heat by cooling furnace

effluent from the discharge of the quench fittings to

approximately 1030C. It is divided into the following three

sections, each of which has a specific operating purpose

Quench Oil Circulating Section

Pan Oil Circulating Section

Rectifying Section



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2.03.1 Quench Oil Circulating (Scrubbing Section)

The effluents from the USC Furnace and USC Recycle Furnace

Quench Fittings flow to the Quench Oil Tower. The effluent from

all of the USC Quench Fittings and the new USC Recycle

Furnace Quench Fitting, Z-131 are routed via the top section of

the Heavy Fuel Oil Stripper C-230.

The vapour and liquid portions of the effluent stream are

separated in the bottom of the Quench Oil Tower and Heavy

Fuel Oil Stripper. The combined vapours rise through the

bottom section of the QO tower contains four trays and a

distributor. The Quench oil distributor is positioned below the

chimneys of the pan oil collection pan.

The Quench Oil Circulating Pumps, P-210 A/B/C, discharge

through the Quench Oil Filters, Z-210 A/B/C which remove any

coke particles, before heat is recovered from the oil. A slip

stream of hot quench oil is fed to the three USC recycle furnace

Quench fittings to better control the outlet temperature from

the three Quench fittings.

Heat is recovered from the quench oil in the Dilution Steam

Generator / Quench Oil Reboilers, E-271 A/H. The cooled

quench oil then flows to the all of the USC Furnace Quench

Fittings and the scrubbing section of the Quench oil tower.CHECKED BY PAGE 28



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2.03.2 Pan Oil Circulation Section

The pan oil (PO) circulating section of the Quench Oil Tower

condenses a portion fuel oil together with any vaporised

quench oil and also cools the cracked gas. The circulating

section contains ten trays, the pan oil collector pan, and the

pan oil distributor.

Vapour, cracked gas, and steam enter the bottom of this

section through the chimneys in the pan oil collector pan. The

pan oil from the collector pan flows to the Pan Oil Circulating

Pump, P-211 A/B from where it is pumped and circulated to

obtain heat recovery. A portion of the uncooled pan oil is sent

to the distributor spray in the Quench Oil Tower scrubbing

section. Another uncooled portion of the pan oil is fed to the

light fuel oil stripper, C-240 on flow control and the balance is

cooled in the pan oil user exchangers. The cooled pan oil is

reintroduced into the Quench Oil Tower pan oil circulating

section via the pan oil distributor.

2.03.3 Rectifying Section

Light Fuel Oil components contained in the vapours entering

the rectifying section are condensed in this section to prevent

their transfer to the QW tower and thereby maintain the end

point of the raw PYROLYSIS gasoline. The required fractionation CHECKED BY PAGE 29



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in this particular section is accomplished by using gasoline

reflux from the base of the Quench Water Tower, C-220 on a

flow control. The light fuel oil components are collected on the

draw - off tray and flow controlled to the light fuel oil stripper,

C-240. Overhead vapour from the stripper returns to the

rectifying section. The Quench Oil Tower overhead, at

approximately 1030C, is sent to the Quench Water Tower, C-

220.

2.04 Heavy Fuel Oil Stripper

The Heavy Fuel Oil Stripper, C-230 strips the light ends from

the heavy Fuel Oil and returns to the Quench Oil Tower.

The stripping effect is achieved by contacting quench oil with

the USC recycle furnaces vapour effluent in the Quench

Fittings, Z-111 and Z-121, and passing the combined mixture

into the Heavy Fuel Oil Stripper, C-230, where separation into

vapour and liquid is achieved.

The separation of light and heavy ends in the Heavy Fuel Oil

Stripper results in a return of light ends into the Quench Oil

Tower and build-up of a large middle boiling range quench oil

inventory as required for circulation and optimum heat

recovery. The heavy fraction separated out in the Heavy Fuel

Oil Stripper bottom contains all the asphaltenes and tar which

are formed in the cracking operation.CHECKED BY PAGE 30



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The heavy fuel oil stripper bottoms liquid is pumped by Heavy

Fuel Oil Product Pumps, P-230 A/B to product blending, cooling

and delivery to plant battery limits.



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

2.05 Light Fuel Oil Stripper

The Light Fuel Oil Stripper, C-240 regulates the quench oil

quality and optimises the heat recovery in the Quench Oil

Tower.

The light Fuel Oil Stripper is fed from two sources. The main

source is the draw off tray in the quench oil tower rectification

section, the second source is the recycle stream form the pan

oil circuit. Stripping of the light components is effected by

dilution steam injection, which enters below the bottom tray.

The stripped vapour returns to the rectification section of the

Quench Oil Tower. The light fuel oil product passes from the

bottoms to the Light Fuel Oil Product Pumps, P-240 A/B, which

discharge it to the fuel oil blending, cooling and delivery

system.

2.06 Quench Water Tower

The cracked gas from the rectification section of the Quench Oil

Tower passes into the Quench Water Tower, C-220. In this

tower, the gas is further cooled to 40.60C, by direct contact

with circulating quench water. Effective contact and cooling of

the gas with quench water are attained by returning the

circulating quench water through distributors in the tower

middle and top sections. For this service, two packed beds are

provided for contacting the gas and quench water.CHECKED BY PAGE 32



SECTION MODULE NO.


CKR-PR-P-001

The flow and distribution of quench water into the middle and

top sections is regulated by flow controllers reset by the

temperature of middle section overhead and top section

overhead, respectively, to attain cooling of the cracked gas and

to provide a hot quench water supply for process reboiling and

heating.

In this tower, dilution steam and the gasoline fraction of the

cracked gas are condensed. The condensed hydrocarbon and

water are separated in the bottom section, which contains a

series of chevron-type plate baffles for the settling out of the

water and hydrocarbon phases. Part of the separated gasoline

is used as reflux to the Quench Oil Tower and the balance feeds

the distillate Stripper, C-250.

Most of the hot water from the base of this tower is circulated

through various process heaters and reboilers before returning

to the quench water tower, while the balance is fed to the

dilution steam generation system.

2.07 Dilution Steam Generation System

Most of the dilution steam contained in the furnace effluent is

condensed in the Quench Water Tower. The reuse of steam

condensate collected form both the condensation of dilution

steam in the Quench Water Tower and in the cracked gas CHECKED BY PAGE 33



SECTION MODULE NO.


CKR-PR-P-001

compression system minimises the demineralized water

makeup requirements and reduces the load on the waste water

effluent treatment system.

Water is circulated by the Quench Water Circulating Pumps, P-

220 A/B/C, to the dilution steam generation system. The water

is first delivered to the water stripper feed filter, Z-261 A/b,

which removes trace solids such s pipe scale and coke that

impair the effectiveness of the downstream coalescer.

The filtered water enters the water stripper feed coalescer, V-

262 A/B, where free hydrocarbon droplets are separated from

the water. These hydrocarbons are returned to the Quench

Water Tower from the top of the coalescer.

The water from the coalescer is heated by exchange against

dilution steam blowdown in the Dilution Steam Stripper

blowdown cooler / stripper feed heater, E-259. The water then

passes through the water stripper feed heater, E-258, where it

is heated against pan oil. It then enters the water stripper C-

260, where it is stripped of dissolved hydrocarbons, acid gases,

and ammonia. Stripping steam is provided from the Dilution

steam Stripper overhead. The overhead vapours flow to the

quench water tower.

The dilution steam stripper feed pumps, P-260 A/B, deliver the

water stripper bottoms to the two dilution steam strippers. The CHECKED BY PAGE 34



SECTION MODULE NO.


CKR-PR-P-001

main portion of the process water is routed to the DSS tower,

C-270, and en-route is heated by exchange against 3.5

kg/cm2g level steam in E-269. The water then passes through

the Dilution Steam Stripper Feed Heater No.1, E-268, where it is

heated against pan oil. The preheated condensate enters the

Dilution Steam Stripper, C-270, above the top tray.

The DSS tower, C-270 bottoms are reboiled against quench oil

in the Dilution Steam Stripper / Quench Oil Reboiler, E-271 A/H,

and against 12 kg/cm2g level steam in Dilution Steam

Stripper / Steam Reboiler, E-270 A/D.

The remaining portion of the process water stream is routed to

the auxiliary DSS tower, C-280 and en-route is preheated

against steam condenste in the auxiliary dilution steam stripper

feed heater, E-279. The preheated process water enters the

auxiliary Dilution steam stripper C-280 above the top tray. C-

280, bottoms are reboiled against 12 kg/cm2g steam in the

auxiliary dilution steam stripper reboiler, E-280 A/C.

Most of the generated dilution steam flows to the cracking

furnaces, where it is used for dilution of hydrocarbon feed,

decoking of furnace tubes, or operating a furnace on hot

standby without hydrocarbon feed. A small portion is used for

stripping in the light fuel oil stripper and LP Water Stripper.

Approximately 5 percent of the steam produced is returned to

the Water Stripper for use as stripping steam.CHECKED BY PAGE 35



SECTION MODULE NO.


CKR-PR-P-001

LMP steam injection into the dilution steam header maintains

sufficient superheat to avoid condensation in the piping to the

furnaces. LMP steam can also be used directly to supplement

the dilution steam to the furnaces. The blowdown, the net

bottoms stream from C-270, is cooled first in the Dilution

Steam Generator Blowdown / Water Stripper Feed Heater, then

against cooling water in the Dilution Steam Generator

Blowdown Cooler, E-273, before being discharged to the oily

water sewer. The blowdown from C-280 is cooled against

cooling water before being discharged to the oily water sewer.

2.08 Distillate Stripper

The Distillate Stripper, C-250, debutanizes the gasoline

collected in the bottom section of the Quench Water Tower and

first three stages of cracked gas compression, before it is fed to

the gasoline hydrotreating unit.

Gasoline from the Quench Water Tower is fed to the stripper by

a slip stream from the quench oil tower reflux pump, P-211 A/B

while the feed from the cracked gas second stage suction drum

is pumped by distillate stripper feed pump, P-230 A/B.

C4’s and light ends from the Distillate stripper are returned to

the cracked gas compressor via the Quench Water Tower.



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

The Distillate Stripper is reboiled by pan oil in the Distillate

Stripper Reboiler, E-250. The gasoline product from the bottom

is pumped via the Distillate Stripper Bottoms Pump, P-250 A/B.

Most of the gasoline from this pump goes to the GHU. A portion

is recycled back to the Quench Oil Tower to provide additional

reflux inventory. The stream is sent to the Quench Oil Tower

Pan Oil section (rather than to the top of the tower) to ensure

that any heavy components are fractionated out.

2.09 Quench Water and Pan Oil circuits

Quench water is circulated to the following users from the

Quench Water tower, C-220, via the quench water circulation

pumps, P-220 A/C, at a temperature of approx. 820C :

Exchanger No. : Description

E-011 Ethane / Propane recycle heater

E-041 Naphtha feed heater

E-051 A/B AGO feed heater no.1

E-210 Fuel oil cooler

E-215 Quench water steam heater

E-340 Weak caustic heater

E-359 Condensate stripper feed heater

E-360 A/B Condensate stripper reboiler

E-410 Demethanizer prestripper reboiler

E-439 Demetahnizer prestripper bottoms heater

E-440 A/C Deethanizer ReboilerCHECKED BY PAGE 37



SECTION MODULE NO.


CKR-PR-P-001

E-530 Secondary deethanizer reboiler

E-535 Tertiary deethaniser reboiler

E-540 A/D Propylene tower auxiliary reboiler

E-542 Propane recycle vaporiser

E-731 Wash oil condenser

Two of the exchangers, E-731 and E-210, provide an additional

heat input to the quench water and a third exchanger, E-215,

utilises steam to adjust the quench water temperature. The

remaining users accept the waster heat from the quench water

system.

After interchanging heat with the QW users, all of the quench

water is cooled in the primary quench water cooler, E-220 A/g,

down to a temperature of 54.40C. The bulk of this water is fed

to the lower packed section of the QW tower. The remainder is

further cooled in the secondary quench water cooler, E-230

A/H, down to a temperature of 37.80C before being fed to the

upper packed section of the QW tower.

Pan oil is circulated to the following users from the quench oil

tower via pan oil circulation pumps, P-211 a/B :-

Exchanger No. Description

E-268 Dilution Steam Stripper Feed Heater No.1

E-258 Water Stripper feed Heater

E-250 Distillate Stripper ReboilerCHECKED BY PAGE 38



SECTION MODULE NO.


CKR-PR-P-001

E-510 Depropanizer Reboiler

The final Pan Oil temperature of 1210C is controlled by

diverting pan oil flow to the pan oil trim cooler, E-219, before

the pan oil is recirculated back to the middle section of the

quench oil tower.

2.10 Compression/Acid Gas Removal/Dehydration

The water saturated hydrocarbon overhead form the quench

water tower is fed to the cracked gas (C G) first stage suction

drum, V-310. The C.G. first stage condensate Pump, P-310 A/B,

discharges the liquid transferred from drum V-320 and any

slugs of liquid carryover in the cracked gas back to the quench

water tower. The vapour from this drum flows to the first stage

of the cracked gas compressor, B-300.

Wash oil is injected into the suction line of each compression

stage by the wash oil Injection Pump, P-300 A/B. Wash oil is

injected to keep the impeller blade tip wet, thus preventing

polymer accumulation. The first three stages of compression

are each followed by an aftercooler and a discharge drum used

to separate water / hydrocarbon condensate from vapour. Heat

is rejected to cooling water in each aftercooler. The first stage

aftercooler, E-310, effluent is combined with gasoline

hydrogenation unit vents in the 2nd stage suction drum, V-320

before entering the 2nd stage of compression. The condensate



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

stripper overhead joins the second stage aftercooler, E-320,

into the 3rd stage suction drum, V-330.

The liquid form the C.G. Third stage Discharge Drum, V-335, is

successively cascaded to the CG. Third stage suction drum and

then to C.G. second stage suction drum, which is designed to

separate the hydrocarbon condensate from the water. The

hydrocarbon condensate from the CG second stage suction

drum is sent to the Distillate stripper, while the water is routed

to the CG 1st stage suction drum. The oily water is pumped via

P-310 A/B to the quench Water Tower, C-220.

To prevent C.G. compressor surging, two minimum flow

bypasses are provided. The first bypass protects the first three

stages of compression, and the second bypass protects the

fourth stage.

The first minimum flow bypass is provided form the third stage

discharge drum to the first stage suction drum. The recycle

automatically protects the compressor by keeping the flow

above surge point during reduced capacity operation.

The third stage discharge gas is passed through a caustic wash

followed by a water wash in the caustic tower, C-340. The acid

free tower effluent is combined with the vents from the

ethylene rectifier and secondary demethaniser reflux drums

and fed to the C G Fourth Stage Drum, V-340. The drum CHECKED BY PAGE 40



SECTION MODULE NO.


CKR-PR-P-001

overhead feeds the Fourth Compression Stage. The discharge

effluent is cooled in the C G Fourth Stage Aftercooler, E-345, by

cooling water and passed to the Cracked Gas Rectifier, C-350,

which fractionates the heavy ends and reduces the gas flow to

the demethaniser system. Reflux for the rectifier is provided by

hydrocarbon condensed in the C G Rectifier Overhead

Condenser, E-355, using propylene refrigerant. The C G

Rectifier Reflux Drum, V-346, is designed to separate the

hydrocarbon condensate from water. The water from the C G

Fourth Stage Suction Drum and C G Rectifier Reflux Drum is

sent to the Third Stage Suction Drum. Bottoms from the C G

Rectifier are discharged to the Fourth Stage Suction Drum.

The Fourth Stage Suction Drum condensate is routed to the

Condensate Stripper Feed Coalescer, V-359, for the removal of

free water. The water is collected in a boot and sent to the

Third Stage Suction Drum. The hydrocarbon stream is heated

against quench water in the Condensate Stripper Feed Heater,

E-359, to prevent hydrate formation and then fed to the

Condensate Stripper, C-360.

In the Stripper, c2s and lighter are recovered overhead and

sent to the C. G . Third Stage Suction Drum. The Condensate

Stripper Bottoms Pump, P-360 A/B, delivers the remaining

hydrocarbons to the Depropanizer, C-510. Stripping vapour is

produced by quench water in the Condensate Stripper Reboiler,

E-360 A/B.CHECKED BY PAGE 41



SECTION MODULE NO.


CKR-PR-P-001

The second minimum flow bypass line, taken from the C.G.

Rectifier overhead, is recycled to the C.G. Fourth Stage Suction

Drum. A small stream taken from upstream of the C.G. Fourth

Stage Aftercooler is used to heat this gas to avoid hydrate

formation across the kick-back minimum flow control valve. In

addition, a bypass stream to the third stage discharge is

provided to ensure adequate vapour loading on the Ripple trays

of the Caustic Tower during reduced capacity operation.

2.10.1 Acid Gas Removal

The caustic wash operation is installed to remove hydrogen

sulphide and carbon dioxide from the cracked gas in order to

meet product quality requirements on the ethylene and

propylene products. Also, the removal of these acid gases

protects downstream catalytic operations, since some acid gas

components are known to be catalyst poisons. Acid gases are

also removed to avoid corrosion and the possible formation of

CO2 ice within the cold process systems.

These acid gases, which are produced in the cracking furnaces,

are removed by scrubbing the gas from the C. G. third Stage

Discharge Drum with circulating caustic solutions in the Caustic

Tower, C-340. The tower is divided into four sections. The three

bottom sections provide for caustic scrubbing of the cracked

gas. The bottom section uses weak caustic, the middle uses CHECKED BY PAGE 42



SECTION MODULE NO.


CKR-PR-P-001

medium caustic, and the top circulates strong caustic. The

fourth section, at the top of the tower, is the water wash

section, which prevents caustic carryover into the cracked gas

Fourth Stage Suction Drum.

The acidic cracked gas enters the caustic tower below the

bottom section where it is contacted with weak caustic

solution. The weak caustic is circulated by the weak caustic

circulating pump, P-342 A/B, then heated against quench water

in the weak caustic Heater, E-340, prior to making contact with

the acidic cracked gas. This ensures that the cracked gas does

not fall below its dew point, which would cause hydrocarbon

condensation.

The cracked gas flows upward, contacting the medium caustic,

and then the strong caustic solution. These streams are

recirculated by the Medium Caustic Circulating Pump, P-343

A/B, and strong caustic circulating Pump, P-344 A/B,

respectively.

Spent caustic solution is contained in the caustic tower bottoms

section, where by any hydrocarbon condensate / polymer oils

are separated out via an overflow weir into a separate hold-up

compartment. The spent caustic is mixed with aromatic

gasoline from the discharge line of the Recirculating Gasoline

Pump, _347 A/B, via the spent caustic /aromatic gasoline mixer,

Z-343 and is then fed to the spent caustic deoiling drum, V-342.CHECKED BY PAGE 43



SECTION MODULE NO.


CKR-PR-P-001

Separation of entrained oil from the spent caustic, and some

hydrocarbon degassing, is achieved in the deoiling drum. The

recovered liquid hydrocarbons are discharged on level control

to quench water tower. The drum pressure floats on the CG 2nd

stage suction Drum pressure. The deoiled spent caustic is then

discharged to the spent caustic Degassing Drum, V-343, which

operates at neat-atmospheric pressure. The residual

hydrocarbon gas is flashed to the flare system, and the spent

caustic is finally pumped to the steam stripper, C-1101 via the

steam stripper feed preheater E-1101.

In the steam stripper benzene and other entrained aromatics

are stripped with live LP steam which is injected below the

bottom tray. The overhead vapour from the tower is recycled

back to the QW tower, via the water K.O. Drum, V-1102, which

collects any slugs of water that may be carried over. The

aromatics free spent caustic bottoms stream is pumped by the

steam stripper bottoms pump, P-1104 A/B to the spent caustic

oxidation unit for further treatment.

In the event that the steam stripper is out of commission the

raw spent caustic liquor can be sent to the spent caustic

holding tank, T-1101 A/B, and subsequently recycled to the

steam stripper utilising the spent caustic feed recycle pump, P-

1101 A/B.



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

Fresh caustic is delivered from offsite as a 20 wt. percent

solution to the concentrated caustic tank, T-340. Makeup

caustic is drawn from the tank by the concentrated caustic

pump, P-341 A/B, and charged to the caustic tower via the

caustic diluent mixer, Z-341, where it is mixed with spent wash

water to produce a 10 percent caustic solution. The wash water

is supplied from the caustic tower wash water loop. The

consumption of caustic depends on the quantity of CO2 and

H2S in the feed to the tower and on the residual concentration

of NaOH in the spent caustic solution.

The Caustic Pump, P-341 A/B, supplies the required makeup

caustic to the Caustic Tower and is used for pH control in the

dilution steam generation system.

The make-up caustic to the caustic tower is combined with the

return circulating strong caustic, whereby the strong caustic

circulating pump provides mixing of the two streams. Excess

strong caustic overflows from the caustic strong section to the

medium section via an external downflow pipe on the strong

caustic chimney tray. In turn, the excess medium caustic

solution overflows to the weak caustic section via an internal

dowflow pipe on the medium caustic chimney tray.

Means for aromatic gasoline (C6-C8 cut) injection is provided

into the top of each of the caustic scrubbing sections. Injection

of gasoline into the suction of the strong caustic circulating CHECKED BY PAGE 45



SECTION MODULE NO.


CKR-PR-P-001

pump is on a continuous basis. The aromatic gasoline acts as a

solvent for any polymers being accumulated on the trays and

passes down with the spent caustic to the Deoiling Drum, V-

342 where it is separated and discharged to the Quench Water

tower.

The neutralised cracked gas passes to the wash water section

where it is cooled by rejecting heat to the circulating wash

water stream. Deaerated boiler feedwater is used as a makeup

supply to the wash water section. The wash water is circulated

by the wash water circulating pump, P-345 A/B, which directs

the water through the wash water cooler, E-341, where it is

cooled against cooling water. The cooled wash water flows to

the top tray of the Caustic Tower.

In the event of a cracked gas compressor shutdown, liquid in

each section of the tower will fall from the Ripple trays towards

the bottom of each section. For the top section, the excess

wash water will accumulate in the wash water chimney tray.

The strong caustic chimney tray is capable of holding the

majority of the dumping liquid from the strong caustic section,

following the provision of a control valve provided on the

external downflow pipe to the medium caustic section which is

to close when the cracked gas compressor trips. The bottoms

compartment below the C G Feed nozzle provides excess liquid

holding capacity for the excess strong caustic solution, and all

of the liquid from the medium and weak caustic sections.CHECKED BY PAGE 46



SECTION MODULE NO.


CKR-PR-P-001

2.10.2 C G Dehydration

The cracked effluent from the overhead of the C G Rectifier

Reflux Drum is fed to one of two cracked gas dehydrators, V-

370 A/B. These fixed-bed dehydrators are each composed of a

main bed and a guard bed. Both beds are filled with molecular

sieve. While one dehydrator is operating the second is either

being reactivated or is in a standby position.

The desiccant in the main bed is designed for a 24 hour

operating cycle at the end of bed life. The desiccant in the

guard section provides additional protection time before water

breakthrough. At the end of each cycle, the standby dehydrator

is put into service and the operating dehydrator is switched

over to reactivation.

Reactivation of the desiccant is accomplished with reactivation

gas (a methane/hydrogen mixture) by upward flow through the

beds. Fresh reactivation gas is supplied from the Demethanizer

System. It is first heated against reactivation gas effluent in the

Reactivation Gas Feed / Effluent Exchanger, E-371, and is then

further heated by HP steam in the Reactivation Gas Heater, E-

372. The hot gas passes upward through the dehydrator,

heating the bed and desorbing the water from the molecular CHECKED BY PAGE 47



SECTION MODULE NO.


CKR-PR-P-001

sieve. The effluent passes to the Reactivation Gas Feed/Effluent

Exchanger where heat is released to cooling water. The cooled

effluent enters the Reactivation Gas Separator, V-371, where

water and hydrocarbon liquids, removed from the desiccant,

are separated from the reactivation gas. The gas is then

returned to the fuel gas system, and the oily water gas is then

returned to the fuel gas system and the oily water is discharged

to the Quench Water Tower. The hot reactivated is discharged

to the Quench Water Tower. The hot reactivated desiccant is

then cooled to the normal temperature with cold residue gas

which is cooled and chilled in the Reactivation Gas Feed Cooler,

E-373, and in the Reactivation Gas Feed Chiller, E-374,

respectively.

2.11 Demethanizer System

The Demethanizer system consists of two parallel feed chilling

trains and three stages of fractionation : the Demethanizer

Prestripper, C-410, the Demethanizer, C-420, and the Residue

Gas Rectifier, C-430.

There are two parallel sets of precoolers. Each set consists of

three heat exchangers, through which the total cracked gas

feed from the dehydrators is cooled and partially condensed

prior to the first liquid fraction being separated in the

Demethanizer Prestripper Feed Drum, V-410, and the

Demethanizer Prestripper Parallel Feed Drum, V-414. The first CHECKED BY PAGE 48



SECTION MODULE NO.


CKR-PR-P-001

parallel set of precoolers are the Demethanizer Precooler No.1,

E-401, and Demethanizer Parallel Precooler No.1, E-407, which

use-6.7 C propylene refrigerant as coolant.

Further cooling of the cracked gas occurs in the Demethanizer

Bottoms Reheater, E-438, and its parallel reheater, E-408,

which utilise the Demethanizer net bottoms stream as coolant.

In Demethanizer Precooler No.2, E-402, and its parallel

precooler, E-409, the cracked gas mixture is cooled by -23.3 C

propylene refrigerant. The liquid condensed at this point

contains some methane and C2s and the major portion of the

C3 and heavier components; it is separated from the vapour in

the Demethanizer Prestripper feed drum, V-410, and its parallel

drum, V-414. The liquid streams from these drums are

combined and fed to the demethanizer Prestripper, C-410, as

the bottom feed for removal of methane.

The vapour from the Demethanizer Prestripper Feed Drum, V-

410 is cooled and partially condensed in the Ethane Recycle

Vaporiser, E-461, where recycle ethane from the Ethylene

Stripper bottoms is vaporised. The partially condensed stream

is further cooled by using -40C propylene refrigerant in the

Demethanizer precooler No.3, E-403. This partially condensed

stream is fed to the Demethanizer feed drum no. 1, V-411, for

separation of the vapour / liquid streams. The vapour from the

Demethanizer Prestripper Parallel feed drum is also cooled by

using-40C propylene refrigerant in the Demethanizer Parallel CHECKED BY PAGE 49



SECTION MODULE NO.


CKR-PR-P-001

Precooler no.3 This partially condensed stream is fed to the

demethanizer parallel feed drum no.1, V-415 for separation of

the vapour / liquid streams.

The liquid streams from V-411 and V-415 contain methane and

C2s, along with much of the remaining C3 and heavier

components. They are combined and fed to the Demethanizer

Prestripper as the top feed. The vapour phase from V-411 is

divided into two parallel streams, after which it is cooled further

and partially condensed. The larger portion of this vapour

stream is cooled by using the -51.1C and -73.3 C levels of

ethylene refrigerant in the reminder is cooled by heat exchange

with residue gas in demethanizer core exchanger no.2, E-412.

Both partially condensed streams are recombined and fed to

the demethanizer feed drum no.2, V-412, where vapour and

liquid streams Are separated. The vapour phase from V-415 is

also cooled using two levels of ethylene refrigerant (-51.1 C and

-73.3 C) in the Demethanizer parallel precooler no.4, E-422. The

partially condensed stream is then fed to demethanizer parallel

feed drum no.2, V-416, where vapour and liquid streams are

separated.

The liquid streams from V-412 and V-416 are combined and fed

to the Demethaniser, C-420. The vapour streams from these

drums (mainly hydrogen, methane, and ethylene) are further

cooled and partially condensed in an exchanger arrangement

identical to that of the previous stage, except for the use of -CHECKED BY PAGE 50



SECTION MODULE NO.


CKR-PR-P-001

100.6 C ethylene refrigerant in the Demethanizer Precooler

No.6, E-406, and Demethanizer Parallel Precooler No.6, E-424,

respectively. The split stream from V-412 is cooled by heat

exchange with residue gas in Demethanizer Core Exchanger

No.3, E-413. A vapour / liquid separation is repeated in the

Demethanizer Feed Drum No.3, V-413, and Demethanizer

Parallel Feed Drum No.3, V-417. The liquid streams, consisting

of ethylene , ethane, and methane, are combined and fed to

the Demethanizer, C-420. The vapour streams are combined

and cooled further and partially condensed in the

Demethanizer core exchanger No.4, E-414, prior to being fed

into the Residue Gas Rectifier, C-430, where the ethylene loss

to fuel is minimised.

The liquid streams from the Demethanizer Prestripper Feed

Drum and Demethanizer Prestripper Parallel Feed Drum, are

combined and fed to the Demethanizer Prestripper, C-410. A

second feed to the Prestripper tower comes form the

Demethanizer feed drum no.1 and the demethanizer parallel

feed rum no.1 The prestripper is reboiled with quench water in

the demethanizer prestripper reboiler, E-410. The stripper

bottoms product is essentially methane free with roughly one

third of the C2 components and goes directly to the

deethanizer, C-440, bypassing the demethanizer, C-420. The

prestripper overhead vapour is fed to the demethanizer.



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

The purpose of the demethanizer is to make a sharp separation

between methane and ethylene. Each feed enters the tower at

different tray locations to gain the maximum benefit from the

pre-fractionation produced by the fractional condensation. The

heat input for the Demethanizer Reboiler, E-420, is supplied by

condensing 7.2 C propylene refrigerant vapour. The

demethanizer condenser, E-425, is cooled by evaporating

ethylene refrigerant at -100.6C. The overhead product vapour

stream is heated as it passes through the Demethanizer core

exchanger no.3 and is then directed to the Methane Expander,

B-421.

The Residue Gas Rectifier recovers the ethylene contained in

Demethanizer Feed Drum No.3, and Demethanizer Parallel

Feed Drum No.3. The liquid from the bottom of the Residue Gas

Rectifier is returned to the top of the Demethanizer, C-420. The

Residue gas overhead is partially condensed in the

Demethanizer core exchanger no.5, E-415, by gas which has

been chilled by expansion in the cryogenic expansion turbine.

The residue gas from the Residue gas rectifier reflux drum, V-

436, is cooled an partially condensed through the Hydrogen

core exchanger, E-419. The partially condensed stream is fed

to the hydrogen drum V-431, where 95 percent hydrogen

vapour is separated from the liquid. The maximum amount of

95 percent hydrogen vapour is sent to the pressure swing

Adsorption Unit, Z-400, for the production of extra high purity

hydrogen. The hydrogen vapour is heated through the CHECKED BY PAGE 52



SECTION MODULE NO.


CKR-PR-P-001

demethanizer core exchanger no.1 through 4 and through the

hydrogen core exchanger.

The remainder of the Hydrogen Drum vapour and the Hydrogen

Drum Bottoms (fuel gas) are flashed down to 1.45 kg/cm2g and

are reheated in the following multi-pass exchangers. Hydrogen

core exchanger, E-419, Demethanizer core exchangers Nos. 1

through 5. The fuel gas and the purge gas from the PSA unit

are then directed to the Fuel Gas Compressor, B-900, at a

temperature of about 320C.

The Demethanizer net overhead vapour stream is heated

through Demethanizer core exchanger no.3 and is then sent to

the Methane Expander, B-421. The expander outlet

temperature is such that the required amount of cooling is

supplied to the overhead rectifier condenser. The expander

effluent, which is at low pressure, is reheated in demethanizer

core exchangers nos. 1 through 5. The heated gas regn. goes

to the Methane Recompressor, B-420. The compressor is driven

by the expander, usually, an integral construction. The gas

leaves the compressor at a pressure of 5.6 kg/cm2g, sufficient

for regeneration requirements.

The Demethanizer bottoms product goes to the Deethanizer

after being heated by exchanger with cracked gas from

precooler no.1



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

The Methane produce stream is obtained by removing a portion

of the liquid from the Demethanizer, Reflux Drum, V-426, and

vaporising in an air vaporiser, E-427, to about 5 C. The vapour

is then allowed to warm-up to ambient temperature by heat

gain from the atmosphere in the pipeline before transfer to

OSBL>

2.12 PSA Unit

The PSA unit, Z-400, provided by UOP, consists of a

prefabricated valve and piping skid, adsorber vessels,

molecular sieve type adsorbent control panel, instrumentation,

and a tail gas surge tank. The unit is designed to permit

outdoor unattended operation. It employs a pressure swing

adosrpiton (PSA) process to purify the 95 mol percent hydrogen

stream supplied from the Demethanizer system.

The PSA process uses a series of adsorbent beds to provide a

continuous and constant hydrogen product flow. The adsorbers

operate on an alternating cycle of adsorption and regeneration.

One adsorber is always in operation while the remaining are in

various stages of regeneration.

The unit produces a high purity hydrogen stream which fulfils

the export product stream requirement, as well as the C2, C3, CHECKED BY PAGE 54



SECTION MODULE NO.


CKR-PR-P-001

C4 and Gasoline hydrogenation unit needs. The hydrogen

stream has a minimum composition of 99.9 mol percent

hydrogen. The balance of the feed gas is purged to the fuel gas

system. Constant hydrogen recovery can be maintained at flow

rates as low as one-third of the design feed flow rate.

2.13 Deethanizer

The dual feed deethanizer , C-440 separates the Demethanizer

and Demethanizer Prestripper bottoms streams into a C2

stream and a C3 and heavier stream. The demethanizer net

bottoms is heated in the Demethanizer bottoms reheater, E-

438, and its parallel reheater, E-408, before entering the tower

as the top feed. The Demethanizer Prestripper Bottoms

Reheater, E-439 A/B, and is the lower feed to the tower.

The Deethanizer gross overhead, consisting primarily of C2’s, is

partially condensed in the Deethanizer condenser, E-445, using

-23.30C propylene refrigerant. The vapour-liquid mixture is

separated in the Deethanizer reflux drum, V-446. The liquid is

returned to the tower as reflux by the deethanizer reflux pump,

P-445 A/B, and the net overhead vapour is directed to the c2

acetylene hydrogenation system.



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

The reboil heat to the tower is supplied by the deethanizer

reboiler, E-440 A/B, using quench water. The deethanizer net

bottoms stream, which is composed of C3’s and heavier

components, is fed to the Depropanizer.



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

2.14 C2 Acetylene Hydrogenation System

Acetylene (C2H2) is produced in the cracking operation and as

an impurity must be removed from the deethanizer overhead

stream by catalytic hydrogenation (Palladium based catalyst),

so that the ethylene product contains less than 2 ppm of

acetylene. Acetylene's are hydrogenated into ethylene and

ethane, which are subsequently separated in the ethylene

fractionation system.

The acetylene is removed in a three step hydrogenation

process. Three identical adiabatic reactors are employed

working in series. The first step is performed by the primary C2

hydrogenation reactor, R-452 A/B which has its own spare. The

second and third steps are performed by the C2 hydrogenation

reactors, R-451 A/B/C, which share a common spare.

The deethanizer net overhead vapour leaving the deethanizer

reflux drum, V-446, is fed to the hydrogenation system on flow

control. Hydrogen from the PSA unit is injected, on ratio flow

control, before it enters the C2 hydrogenation feed / effluent

exchanger, E-452 A/D, and is steam heated by C2

hydrogenation feed heater, E-450, where the inlet temperature

to the FIRST reactor is made in the first reactor. The reaction is

controlled by adjusting the reaction temperature and by

bleeding in raw hydrogen containing CO into the pure hydrogen

stream from the PSA unit.CHECKED BY PAGE 57



SECTION MODULE NO.


CKR-PR-P-001

The effluent from the first reactor passes through the C2

hydrogenation adiabatic reactor Intercooler No.1, E-458, where

the inlet temperature to the second reactor is controlled. A split

range flow control system is provided such that part of the flow

may be by-passed across E-458 for better temperature control.

Hydrogen is injected on ratio flow control, upstream of E-458.

Approximately 35% of the conversion of the acetylene is made

in the second reactor. The reaction is controlled by adjusting

the reaction temperature and by bleeding in raw hydrogen

containing CO into the pure hydrogen stream from the PSA

unit.

The effluent from the second reactor is cooled in the C2

Hydrogenation Adiabatic Reactor Intercooler No.2, E-455,

before passing to the third reactor. Hydrogen is again injected

on ratio control. In this reactor, the remaining acetylene is

removed so that the reactor effluent contains less than 1.7 ppm

acetylene. The reaction is controlled by adjusting the reaction

temperature and by bleeding in raw hydrogen containing CO

into the pure hydrogen stream from the PSA unit.

Effluent leaving the third reactor is water-cooled in C2

hydrogenation Adiabatic Reactor Afterooler, E-456 A/B, prior to

preheating the feed to the first reactor in the C2 hydrogenation

feed / effluent exchanger, E-452 A/D.



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

The reactor beds are periodically regenerated using

regeneration gas supplied from the reactor treatment furnace,

H-710, in the gasoline hydrogenation Unit. The three reactors,

R-451 A/B/C are rotated such that the newly regenerated bed

assumes the third reactor position.

The effluent from E-452 A/D passes to the C2 hydrogenation

effluent separator, V-455, where condensed polymers are

knocked out prior to the effluent being dried in the secondary

dehydrators, V-453 A/B. After drying, the effluent passes to the

Ethylene rectifier, C-470. The secondary dehydrators are

supplied for removal of any water formed in the acetylene

hydrogenation reaction any polymers not removed in the C2

Hydrogenation effluent separator. While one dehydrator is

operating, the second is either being reactivated or is in a

standby operation. Reactivation of the desiccant is

accomplished by upward flow of reactivation gas through the

beds. The reactivation gas is supplied from the same system

employed by the cracked gas dehydrators, V-370 A/B.

2.15 Ethylene Fractionation

The C2 acetylene hydrogenation system feeds the two-tower

ethylene fractionation system. The feed stream consists

essentially of ethylene and ethane with trace quantities of

methane, hydrogen and propylene. This system fractionates

the feed into an ethylene product stream and an ethane stream

for recycle cracking in the furnaces.CHECKED BY PAGE 59



SECTION MODULE NO.


CKR-PR-P-001

A pasteurising section is located at the top of the ethylene

rectifier, C-470, above the ethylene product drawoff, to

separate any lights from the ethylene product. The rectifier

gross overhead is condensed against -400C propylene

refrigeration in the ethylene rectifier condenser, E-475. The

condensed liquid is collected in the ethylene Rectifier Reflux

Drum, V-476, then pumped back to the top pasteurising tray by

the ethylene rectifier reflux pump, P-475 A/B. A vent is

recycled from the drum to the C. G. Fourth Stage Suction Drum.

Below the pasteurising section, the ethylene product is

withdrawn as liquid and fed under its own pressure to the

intermediate storage spheres.

The option also exists to either send the ethylene product to

atmospheric storage via the ethylene product coolers no.1,2 &

3, E-480, E-481, E-482 respectively, or to vaporise the ethylene

product and deliver it as a low pressure vapour to the battery

limits via the ethylene product vaporiser, E-477, and ethylene

product superheater, E-478 A/b.

Normally, the ethylene liquid will be imported from the

intermediate storage spheres after quality control and either

fed as a low pressure liquid to the ethylene product vaporiser,

E-477, and ethylene product superheater, E-478 A/B to produce

a low pressure vapour for export or fed as a high pressure

liquid to the HP ethylene product heater no.1, E-40, and HP CHECKED BY PAGE 60



SECTION MODULE NO.


CKR-PR-P-001

ethylene product no.2, E-491, to produce a high pressure

vapour for export.

Both ethylene fractionation towers are equipped with reboilers.

Desuperheated ethylene refrigeration compressor discharge

vapour is the reboiling medium for the ethylene rectifier

reboiler, E-470. Propylene refrigerant vapour at 7.20C is the

reboiling medium for the ethylene stripper reboiler, E-460.

The ethylene stripper, C-460, net bottoms supplies the ethane

recycle. The ethane recycle is routed to the ethane recycle

vaporiser, E-461, superheated in the demethanizer core

exchanger no.1, E-411, and then delivered to the USC recycle

furnace as feed for cracking.

2.16 Depropaniser

The dual-feed Depropanizer, C-510, is fed by the Deethanizer

bottoms and condensate stripper bottoms. Propylene, propane,

and any lighter components make up the tower overhead. This

stream is totally condensed by vaporising 9.40C propylene

refrigerant in the Depropanizer condenser, E-515. The

condensed liquid is collected in the Depropaniser Reflux Drum,

V-516. The liquid is pumped to the tower as reflux by the

Depropanizer Reflux pump, P-515 A/B. The net overhead

stream is pumped by the C3 hydrogenation feed pump, P-516

A/b, to the C3 Hydrogenation system.CHECKED BY PAGE 61



SECTION MODULE NO.


CKR-PR-P-001

The Depropanizer gross bottoms is reboiled against pan oil in

the Depropanizer Reboiler, E-510 A/B. The net bottoms stream,

composed mainly of C4’s and heavier components, is sent to

the Debutanizer.

2.17 C3 Hydrogenation System

The C3 Hydrogenation system, designed by Institut Francais du

Petrole (IFP) is a one stage, liquid-phase catalytic process.

There are three installed reactors, R-531 A/B/C. Two are

normally operated in parallel while the third is on stand-by.

Methyl acetylene (MA and propadiene (PD) in the Depropanizer

net overhead are selectively converted to propylene and

propane in the reactors.

The condensed Depropanizer net overhead is pumped into the

system by the C3 Hydrogenation Feed Pump, P-516 A/B. This

stream first flows through the C3 hydrogenation feed coalescer,

V-519, which eliminates any free water. The coalescer outlet is

split into two parallel passes, one for each operational reactor.

Each pass is diluted with liquid C3 recycled from the C3

hydrogenation recycle pump, P-520 A/B, and then mixed with

make-up hydrogen from the PSA unit. The purpose of the liquid

recycle is to control inlet concentration of MA+PD in the reactor

feed. This avoids excessive vaporisation in the reactors due to

the highly exothermic reactions.



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

In the reactors, MA and PD are selectively hydrogenated to

propylene, propylene hydrogenation to propane is minimised.

The heat of reaction induces partial vaporisation of the

hydrocarbon stream.

Purge to the C.G. Fourth Suction Drum). During normal

operation, the effluent is sub-cooled and no off-gas is purged.

The drum bottoms are pumped out by the C3 hydrogenation

recycle pump, P-520 A/B, and divided into two streams : liquid

recycle for reactor feed dilution and the product which feeds

the secondary deethanizer, C-530.

The spare reactor allows catalyst reduction, reactivation or

regeneration operations with the C3 Hydrogenation unit

running.

For catalyst reduction or reactivation operations, hydrogen

make-up gas is combined with fuel gas of the methane type to

achieve mixed stream hydrogen content of 25 mol%.

Alternately, nitrogen may be used instead of fuel gas. The

mixed stream is then preheated to the required temperature in

the C3 hydrogenation catalyst treatment exchanger, E-522. The

off-gas, which is similar to the inlet gas, is sent to flare for

disposal.CHECKED BY PAGE 63



SECTION MODULE NO.


CKR-PR-P-001

The reactors are regenerated, as required, by regeneration gas

supplied from the GHU first Stage Reactor Treatment Furnace,

H-710. Spent regeneration gas is returned to the GHU decoking

drum, V-713, for disposal. The composition of the spent gas is

similar to the fresh regeneration gas except that it contains

small amount of light hydrocarbons at the beginning of reactor

sweeping and CO/CO2, during combustion steps.

2.18 Secondary and Tertiary Deethanizer

Secondary and Tertiary Deethanizer,C 530 & C-535, towers in

series are designed to remove water and C2 and lighter

hydrocarbons from the propylene / propane stream prior to C3

fractionation.

The liquid effluent from the C3 hydrogenation system is fed to

the secondary deethanizer at tray number 22. The overhead

vapour stream is condensed against cooling water in the

secondary Deethanizer condenser, E-535. Following the

separation of water in the secondary Deethanizer reflux drum,

V-536, the total hydrocarbon condensate phase is pumped

back to the top of the tower by the secondary deethanizer

reflux pump, P-535 A/B. Noncondensables in the secondary

deethanizer overhead are normally vented to the cracked gas

fourth stage suction drum. Any condensed water is removed



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

from the boot of the reflux drum and is sent to the oily-water

sewer.

The secondary deethanizer reboiler, E-530, is heated by quench

water. The tower bottom stream flows to the Tertiary

Deethanizer, C-535 via the secondary deethanizer bottoms

pump, P-530 A/B.

The Tertiary Deethanizer, C-535, tower has been added to the

system in series with the secondary deethanizer to

accommodate the increased expansion loads. It is designed to

further remove water and C2 and lighter hydrocarbons from the

propylene / propane stream prior to C3 fractionation to meet

the required product specifications.

The Secondary Deethanizer Bottoms Pump effluent is fed to the

Tertiary Deethanizer, C-535, at tray number 22. The overhead

vapour stream is condensed against cooling water in the

Tertiary Deethanizer Condenser, E-537. Following the

separation of water in the Tertiary Deethanizer Reflux Drum, V-

537, the total hydrocarbon condensate phase is pumped back

to the top of the tower by the Tertiary deethanizer reflux pump,

P-537 A/B. Noncondensables in the Tertiary Deethanizer

overhead are vented to the cracked gas Fourth Stage Suction

Drum. Any condensed water is removed from the boot of the

Reflux Drum and is sent to the oily-water sewer.



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

The Tertiary Deethanizer Reboiler, E-536, is heated by quench

water. The tower bottom stream flows to the Propylene

Stripper, c-540, via the Tertiary Deethanizer Bottoms Pump, P-

536 A/B.

2.19 Propylene Fractionation

The net bottoms stream from the secondary deethanizer,

containing propylene, propane, plus trace amounts of ethane

and C4’s , is fed to the propylene stripper, C-540. Because of

the large number of trays required to make the separation, two

towers are provided for the propylene / propane fractionation :

the Propylene Stripper, C-540, and the Propylene Rectifier, C-

550. Reboil heat I supplied to the bottom of the stripper by

circulating quench water in the Propylene Tower Reboilers, E-

540 A/D and if necessary by the Propylene Tower Auxiliary

Reboilers, E-541 A/B. The Stripper bottoms stream consists of

propane recycle which is vaporised in the Propane Recycle

Vaporiser, E-542, and is sent to the USC Recycle Furnaces for

cracking. Green oil formed in the C3 hydrogenation reactor is

continuously drained from E-542 and is sent back to the 2nd

stage suction drum V-320.

Vapour from the top of the stripper flows to the bottom of the

propylene rectifier. Liquid from the bottom of the rectifier is

pumped back to the top of the stripper via the propylene

transfer pump, P-550 A/B. Overhead vapour from the rectifier is

condensed using cooling water in the propylene tower CHECKED BY PAGE 66



SECTION MODULE NO.


CKR-PR-P-001

condenser, E-555 A/H, and passes to the Propylene tower reflux

drum, V-556. Condensate from the reflux drum is pumped to

the top of the rectifier as reflux and to offsite propylene storage

and uses by the propylene tower reflux / product pump, P-555

A/B. A slip stream, located off the propylene product stream

provides make up to the propylene refrigeration system, as

needed.

2.20 Debutanizer

The Depropanizer bottoms stream is fed to the debutanizer, C-

560. The tower gross overhead is condensed against cooling

water in the debutanizer condenser, E-565. The mixed C4’s

stream is pumped by the Debutanizer Reflux / Product Pump, P-

565 A/b, from the Debutanizer reflux drum V-566, to the C4

hydrogenation unit / intermediate storage and back to the

tower as reflux.

The Debutanizer bottoms stream is reboiled against LLP steam

in the Debutanizer Reboiler, E-560 A/B. The tower net bottoms,

consisting of C5s and heavier, are sent to the Gasoline

Hydrogenation Unit.

2.21 C4 Hydrogenation System :

The raw C4 cut is routed to the feed surge drum, V-801 and

then pumped under flow control by the feed pump, P-801 A/B.



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

The vessel pressure is regulated at 4.5 kg/cm2g by a split range

control which regulates the N2 make up and release to flare.

The flow rate of hydrogen make up is regulated by flow ratio

control with the C4 feed. This flow ratio set point is calculated

in proportion to the butadiene content at reactor inlet

(feed+recycle).

The C4 cut feed is mixed with liquid recycle and hydrogen

make up gas and flow to the top of the reactor R-801. The

hydrogenation reaction is exothermic and a cooled recycle

stream is required to be mixed with the C4 feed and hydrogen

in order to prevent excessive temperatures within the catalyst

bed and in order to ensure a good hydraulic distribution

through the catalyst bed.

As the mixture flows down through the catalyst bed of the

reactor R-801, the temperature rises due to the exothermic

reaction. The inlet temperature of the reactor R-801 is

minimised (in order to prolong the active life of the catalyst)

consistent with achieving the required conversion rate of

diolefinic hydrocarbons. As the catalyst activity reduces, during

the run life, the feed temperature is increased form about 430C

at start of run (SOR), to about 600C at end of run (EOR). The

reactor outlet temperature should not exceed 1000C in order to

prevent excessive damage to the catalyst. Below 400C the



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

reaction rate is not sufficient to achieve the required

conversion, even with fresh catalyst.

Steam preheating through the heater E-801 is necessary during

start-up to reach the inlet R-801 temperature.

The volume of the gaseous phase in the mixture reduces as

hydrogen reacts with the diolefinic hydrocarbons but some of

the C4 hydrocarbons are vaporised as the temperature rises.

The two phase mixture leaving the reactor R-801 flows directly

to the Hot Separator, V-802. Vapour from the Hot Separator V-

802 is cooled in the post-condenser, E-803. The condensate

which is formed, is separated in the post-condenser drum, V-

803, and is recycled to the separator V-802 after mixing with

reactor R-801 effluent. First reaction section pressure is

controlled by purging V-803 gas to the cracked gas compressor

suction.

The liquid collected in the Hot Separator is pumped by the

Recycle Pump, P-802 A/B and cooled in the Recycle Cooler, E-

802. Most of the cooled liquid represents the R-801 recycle

and the other part represents the first stage effluent. A

separate bypass control around the cooler E-802 enables the

regulation of R-801 inlet temperature.



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

A second separate E-802 by-pass control enables the regulation

of the R-802 inlet temperature. This stream is sent under flow

control to the second stage hydrogenation reactor R-802.

The H2 make up to the finishing reactor R-802 is delivered

under flow ratio control. the set point of this flow ratio is

calculated in proportion to the butadiene content at R-802 inlet.

R-802 effluent is cooled down to 430C through the product

cooler, E-804, and flashed into the c4 product flash drum, V-

804 at fuel gas network pressure to eliminate potential remains

of hydrogen or other light components. the liquid product is

pumped to battery limit under level control by the C4 product

pump.

An identical unit called as auxilary hydrogenation is installed to

operate in parallel to main unit for additional loads .

2.22 Ethylene Refrigeration System

The Ethylene Refrigerant Compressor, B-600, is a three stage

single casing machine. The machine is designed to supply

ethylene refrigerant at -100.60C, and -51.10C, respectively. The

compressor is driven by a steam turbine.

The compressor third stage discharge vapour is desuperheated

by using cooling water in the Ethylene Refrigerant

Desuperheater No.1, E-645, then by using 7.2 C and -6.7 C CHECKED BY PAGE 70



SECTION MODULE NO.


CKR-PR-P-001

propylene refrigerant in the Ethylene Refrigerant

Desuperheaters No.2, E-646, and no.3, E-647, respectively. The

refrigerant vapour then flows through the ethylene refrigerant

oil filter, z-610 A/B, for removal of compressor lube or seal oil.

The takeoff for the minimum flow bypass line is downstream of

the filter. Normally, the desuperheated vapour is condensed in

the ethylene rectifier reboiler, E-470 A/B. For start-up and upset

conditions, the auxiliary ethylene refrigerant condenser, E-649

condensing the desuperheated ethylene vapour as required.

The condensed ethylene refrigerant flows to the ethylene

refrigerant surge drum, V-645.

The liquid from the surge drum is sub cooled using -40.00C

propylene refrigerant in a plate - fin exchanger, the ethylene

refrigerant subcooler, E-650. The subcooled liquid flows into the

ethylene refrigerant third stage suction drum, V-630, via a level

control valve. A slip stream of the subcooled liquid flows to the

ethylene product cooler no.1 refrigerant flash pot, V-480 and

demethanizer parallel precooler no.4 flash pot A, V-422, which

service ethylene product cooler no.1, E-480 (normally not in

service) and demethanizer parallel precooler no.4, E-422A,

respectively).

The third stage suction drum pressure is maintained by the

compressor, resulting in a refrigerant temperature of -51.10C.

This drum serves as a thermossyphon drum for demethanizer



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

precooler no.4, E-404. The flash vapour generated in this drum

flow to the third stage suction nozzle of the compressor.

A portion of the -51.10C liquid flows into the ethylene product

cooler no.2 refrigerant flash pot, V-481, servicing the ethylene

product cooler no.2, E-481 and demethanizer parallel precooler

no.4 flash pot B, V-423, servicing the demethanizer parallel

precooler no.4, E-422B. The balance of the liquid from V-630, is

fed into the ethylene refrigerant second stage suction drum, V-

620, via a level control valve.

The second stage suction drum pressure is maintained at a

corresponding liquid temperature of -73.30C. This drum serves

as a thermosyphon drum for Demethanizer Precooler No.5, E-

405. The vapour generated in this drum flows to the second

stage suction nozzle of the compressor.

A majority of the -73.30C liquid satisfies four parallel process

users: the Demethanizer Precooler No.6, E-406; Ethylene

Product Cooler no.3, E-482; Demethanizer Condenser, E-425;

and Demethanizer Parallel precooler No.6, E-424. The ethylene

vapour out of the associated flash pots of these users is sent to

the ethylene Refrigerant first stage suction drum, V-619, at -

100.60C.

The entire first stage suction drum vapour is sent to the

ethylene refrigerant compressor.CHECKED BY PAGE 72



SECTION MODULE NO.


CKR-PR-P-001

Any accumulation of oil or liquid in the first stage suction drum

flows into the ethylene refrigerant drain drum, V-646. This

drum is equipped with a propylene refrigerant heating coil,

receiving propylene vapour upstream of propylene refrigerant

condenser, E-699 A/H, J/K, and discharging condensed

propylene liquid to the propylene refrigerant fourth stage flash

drum, V-690. Any ethylene refrigerant liquid in the drain drum

is evaporated, allowing the oil to accumulate and be

periodically drained from the drum.

Three minimum flow bypasses are provided into the

compressor suction drums to maintain the compressor in a

stable flow regime.

2.23 Propylene Refrigeration System

The Propylene Refrigerant Compressor, B-650, is a four stage

single - casing machine, which is designed to supply propylene

refrigeration at -400C, -23.30C, -6.70C and 7.20C, respectively.

The compressor is driven by an extraction condensing steam

turbine.

The compressor discharge vapour is desuperheated and

condensed in the water cooled propylene refrigerant condenser

, E-699 A/H, J/K.



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

The minimum flow bypass is taken upstream of the propylene

refrigerant condenser. As required , this vapour goes to the

propylene refrigerant first stage suction, second stage suction,

third stage flash, and fourth stage flash drums.

The condensed propylene from E-699 A/H, J/K, flows into the

propylene refrigerant surge drum, V-695. The drum pressure is

maintained by saturated compressor discharge vapour. This is

necessary to prevent “stonewall operation”.

The liquid propylene at 40.60C flows from the surge drum and

divides into three separate streams. The propylene is

subcooled in all three streams, acting as the heating medium

for process streams. These services are :

Demethanizer core exchanger no.1, E-411. The subcooled

propylene flows to propylene refrigerant second stage suction

drum, V-670.

Ethylene product superheater, E-478 A/B. The subcooled

propylene flows to propylene refrigerant third stage flash drum,

V-680.

HP ethylene product heater no.2, E-491. The subcooled

propylene is divided into three parallel process services.

Reactivation gas feed chiller, E-374, Depropanizer condenser,

E-515 and cracked gas rectifier overhead condenser, E-355. CHECKED BY PAGE 74



SECTION MODULE NO.


CKR-PR-P-001

The vapour generated in these services and the balance of

liquid propylene refrigerant each flow to the propylene

refrigerant fourth stage flash drum, V-690.

The Fourth Stage flash drum vapour is used as the heat source

in the ethylene stripper reboiler, E-460, and demethanizer

reboiler, E-420. The condensed propylene flows through the

respective seal pots and is flashed into the propylene

refrigerant third stage flash drum, V-680.

The fourth stage flash drum operates at 7.20C. This drum

serves as a thermosyphon drum for ethylene refrigerant

desuperheater no.2, E-646. Some of the liquid is vaporised in

the demethanizer precooler no.1, E-401, and demethanizer

parallel precooler no.1, E-407. The balance of the liquid is

flashed directly to the third stage flash drum, V-680.

The third stage flash drum vapour, is condensed in the ethylene

product vaporiser, E-477, and the HP Ethylene product heater

no.1, E-490. The propylene condensed in these exchanger is

collected in the respective seal pot, V-477 and V-490, then

flashed to the propylene refrigerant second stage suction drum,

V-670.

The third stage flash drum operates at -6.70C. This drum serves

as a thermosyphon drum for the ethylene refrigerant

desuperheater No.3, E-647. The liquid propylene from the drum CHECKED BY PAGE 75



SECTION MODULE NO.


CKR-PR-P-001

supplies the following four services: Auxiliary ethylene

refrigerant condenser, E-649 A/B; Deethanizer condenser, E-

445 A/D; Demethanizer precooler No.2, E-402, and

Demethanizer Parallel precooler no.2, E-409. The vaporised

propylene is sent to the propylene refrigerant second stage

suction drum, V-670. Additionally, the third stage flash drum

liquid is flashed into the second stage drum.

All of the vapour from the second stage suction drum, at -

23.30C, is routed to the compressor. Some of the liquid satisfied

three parallel process users : Demethaniser parallel precooler

no.3, E-421; Demethanizer Precooler no.3, E-403 and ethylene

refrigerant subcooler, E-560. The propylene vapour out of these

services is sent to the propylene refrigerant first stage suction

drum, V-660. The balance of the liquid is flashed into the first

stage suction drum to satisfy the ethylene rectifier condenser,

E-475, requirement.

The first stage suction drum serves as a thermosyphon drum

for the ethylene rectifier condenser. The entire first stage

suction drum vapour is sent to the refrigerant compressor. Any

excess liquid in the first stage suction drum may be sent to the

LLP steam-traced propylene refrigerant drain drum, V-696. The

vapour from the drain drum is returned to the first stage

suction drum.

2.24 Gasoline Hydrogenation UnitCHECKED BY PAGE 76



SECTION MODULE NO.


CKR-PR-P-001

The GHU consists of two stages. This process provided by

Institut Francais du Petrole (IFP) produces a feedstock for

downstream aromatic recovery by selectively hydrogenating

the diolefins in the first stage and the olefins in the second

stage.

2.24.1 First stage reaction section

The raw pyrolysis gasoline, mixed with the recycled wash oil, is

fed to the feed surge drum, V-701 under slight pressure, after

being filtered through the Z-702 A/B package. The filtration

facility is mostly useful when some of the feed comes from the

storage tanks. Free water, if any, can be purged from V-701

boot.

The first stage feed pump, P-701 A/B raises the feed pressure

up to the reaction selection pressure. Part of the P-701

discharge can be routed to storage under V-701 level control.

H2 make up supply is introduced at the First stage feed pump

discharge under pressure control. The pressure of both reaction

sections, HD1 and HD2, is controlled from the same point, at

the top of the 2nd stage separator drum, C-740.

The fresh feed and H2 make up are mixed with cooled reactor

effluent to dilute the feed. The role of the dilution is to lower



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

the feed reactivity and thus obtain a smooth control of

temperature elevation in R-710 A/B first catalyst bed.

The mixed stream is charged to the reactor after heating

through E-701, reactor feed effluent heat exchanger. R-710 A/B

reactor inlet temperature is controlled by by-passing part of the

reactor effluent around E-701. During start-up periods, the

temperature is controlled by means of the steam preheater E-

702.

The reactions (diolefins and alkenyl aromatics hydrogenation)

occur in mixed phase (mainly liquid) in a fixed bed type reactor

R-710 A/B. The catalyst is divided into two beds. The overall

temperature profile through the reactor is controlled by dilution

of feed, as mentioned above, and by the injection of quench

under temperature flow control cascade (TC at the inlet of

second bed).

Reactor R-719 effluent, partly cooled through E-701, is flashed

into the Hot Separator, V-710. Part of the liquids is recycled as

quench and dilution via the First stage quench pump, P-710 A/B

and First stage quench cooler, E-711. The remainder is sent

under level flow control cascade etc. the depentanizer, C-720.

V-710 vapour phase is cooled down through the hot Separator

Vapour Condenser , E-712 and flashed into cold separator V-

711. V-711 liquid is fed to C-720 under level control.CHECKED BY PAGE 78



SECTION MODULE NO.


CKR-PR-P-001

V-711 vapour feeds the second stage reaction section as

hydrogen rich make-up.

Decoking drum V-713 collects the regeneration effluents of first

and second stage reaction section, as well as C3 and C4

hydrogenation units.

Depentaniser:

The first purpose of the depentanizer C-720 is to stabilise the

first reactor product by eliminating the light components which

have been dissolved under high pressure in V-710 and V-711.

The second purpose is to split the C5 cut from the C6+ cut.

Stabilisation is performed in the uppermost trays. The overhead

vapours of C-720 are condensed in the depentanizer

condenser, E-725 and the liquid collected in reflux drum, V-726.

Reflux drum V-726 vapour phase is purged to flare or to

cracked gas compressor under pressure control.

The V-726 liquid is pumped by the depentanizer reflux pump, P-

725 A/B, as external reflux under flow control reset by level

control.



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

The C5 cut is withdrawn in liquid phase under temperature flow

cascade control, and sent to battery limit after being water

cooled through the C5 product cooler, E-726.

The depentanizer reboiling is performed by the thermosyphon

reboiler E-720. C6 + Cut is fed to the deoctanizer, C-730, under

flow control reset by C-720 bottom level control.

Deoctoniser:

The purpose of the Deoctanizer, C-730 is to split the C6+ cut

into C6-C8 cut and C9+ cut, and also to withdraw a C9-2000C

wash oil cut.

C-730 is operated under slight vacuum in order to limit the

bottom temperature to 1750c and to allow the reboiling with

saturated LMP steam. Vacuum is maintained by means of

steam ejector Z-736. The pressure is controlled at the top of C-

730 by recycling MP steam at Z-736 outlet into the ejector

together with the non condensable components issued from

the column through post condenser, E-736.

The overhead vapours of C-730 are condensed in the

deoctanizer condenser, E-735, and the liquid is collected in

reflux drum, V-736.

The Deoctanizer Reflux Pump, P-735 A/B, sends the external

reflux to the column under flow control. The distillate feeds the



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

second stage reaction section via the 2nd stage feed pump, P-

736 A/B, under flow control, reset by V-736 level control.

The Deoctanizer reboiling is performed by the thermosyphon

reboiler, E-730 A/B which is controlled by temperature control

of the bottom section of the tower.

C9+ cut is sent to battery limit via the deoctanizer feed pump,

P-730 A/B and water cooler, E-732.

The wash oil is withdrawn as a vapour phase 3 trays above the

bottom of the column. It is condensed in water cooler, E-731,

and collected in the wash oil holding drum, V-731. It is sent to

the battery limit via the wash oil transfer pump, P-731 A/B and

wash oil trim cooler, E-737, under flow control.

2.24.3 Second Stage Reaction Section

The feed to second stage reaction section is pumped via the

2nd stage feed pump, P-736 A/B under flow control reset by V-

736 level control. Fluctuation in V-736 level can also be

smoothed by the option of sending feed to storage.



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

The feed is mixed with recycle and make up gas at the

compressor B-740 A/B discharge, before being heated up

through E-740 A/B/C/D/E feed effluent exchanger and feed

heater H-740. The second stage reactor inlet temperature is

controlled by the furnace H-740.

The reactions (hydrogenation of olefins and desulfurization)

occur in vapour phase on a fixed bed type reactor R-740 filled

with two types of catalysts :

LD 145 : mainly hydrogenation

HR306C : mainly desulfurisation.

The temperature profile through the reactor is kept under

control by the injection of quench between the two catalyst

beds regulated by temperature control of the second bed.

The effluent of R-740 is flashed in the second stage separator,

V-740, after consecutive cooling in E-740 A/B/C/D/E and E-741

water cooler.

V-740 vapour phase is partly released to flare or to cracked gas

compressor under flow control. The overall pressure control is

ensured from V-740 by action on H2 make-up to the first

reaction section. Both reaction section pressures are controlled

through this pressure control.



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

The remaining vapour phase is recycled to the 2nd stage K.O.

drum, V-741, where it is mixed with first stage cold separator,

V-711, vapour, which is the h2 rich make up to the second

stage reaction section.

Both gases are sent under flow control back to the 2nd stage

reaction section via the recycle and make up compressor, B-

740 A/B.

The V-740 net liquid phase is fed to stripper section under level

flow cascade control, while some liquid is recycled as quench to

the reaction section via the 2nd stage quench pump, P-740 A/B.

2.24.4 Stripper Section

The purpose of the stripper, C-750, is to eliminate H2S and light

components dissolved at high pressure in the C6-C8 cut.

Before being fed to the stripper, the C6-C8 cut is heated up

against stripper bottom product through the feed / effluent

exchanger, E-749 A/B.

The stripper overhead vapours are partially condensed in the

stripper Condenser, E-755 and collected in reflux drum V-756.

The reflux is returned to the column by the reflux pump, P-755

A/B, under flow control reset by V-756 level control.CHECKED BY PAGE 83



SECTION MODULE NO.


CKR-PR-P-001

V-756 vapour phase is purged to flare or to the cracked gas

compressor under column overhead pressure control.

The stripper reboiling is performed by the thermosyphon

reboiler, E-750, using LMP steam.

The bottom product is pumped under level control to battery

limit by the C6-C8 product pump, P-750 A/B through the feed /

effluent exchanger, E-749 A/B and water cooler E-751.

the pump, P-752 is provided for the injection of corrosion

inhibitor into the stripper overhead.

The First stage reactor treatment furnace, H-710 is provided to

service the First stage reactor R-710 A/B, and the C2, C3 and

C4 reactors during catalyst treatments.

The purpose of the spent caustic oxidation unit is to oxidise the

sodium sulphide in the spent caustic as completely as

practicable to harmless sodium sulphate, to cool the resulting

effluent, and sent it to the effluent treatment plant.

Spent caustic is gasoline washed, de-oiled, stripped with steam,

cooled and sent to the SCO feed surge drum, V-1121, which is

nitrogen-blanketed and vented to the wet flare system.



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

Alternatively, the spent caustic feed is pumped from holding

tank T-1101 A/B by P-1101 A/B, and sent to V-1121.

Spent caustic from V-1121 is pumped by reactor feed pump P-

1121 A/B on flow control through feed / vent gas exchanger E-

1122 A/B, where it is heated on temperature control. The

heated spent caustic is sent to the bottom of R-1122A, the first

reactor in a series of three.

The three reactors are fed with air from reactor feed air

compressor B-1121 A/B/C, by way of air surge drum V-1123.

The air is sent under pressure control through feed air filter Z-

1121 A/B/C to two flow controllers on each reactor, supplying a

special distributor at the bottom of each reaction zone. Each

distributor is also fed with desuperheated steam on flow

control.

Each reactor operates nearly full of liquid at 1300C, and is

divided into two zones by a valve tray. The spent caustic flows

slowly upward in contact with a stream of fine air bubbles.

The reactor pressures are individually controlled to allow the

flow of spent caustic through each reactor, under level control.

On the spent caustic stream from each reactor, a filter Z-1123

A/B/C is provided for removal of possible agglomerated

polymer.CHECKED BY PAGE 85



SECTION MODULE NO.


CKR-PR-P-001

The residence time in each reactor is approximately 4 hours at

the maximum design rate.

The high reactor temperatures required for good oxidation are

maintained by adjustment of the steam injection rates. The

sulphide content is highest in R-1122A, which therefore

requires more air than the other reactors. Heat from the

oxidation reactions is also highest in R-1122A, causing its

steam injection rate to be the lowest.

Oxidised spent caustic from R-1122C is filtered in Z-1123C,

cooled in E-1121 A/B, and released on level control to effluent

surge drum V-1122.

The vent gases from the reactors are released by their pressure

controls, and combined before flowing through feed / vent gas

exchanger E-1122A/B and vent gas cooler E-1123A/B to V-1122.

Vent gas from V-1122 is released on pressure control to

atmosphere at 400C. It consists mainly of nitrogen and oxygen,

with a small amount of water vapour. The oxidised spent

caustic from V-1122 at 400C is pumped by the effluent transfer

pump P-1122 A/b on level control to the T-1101 product tank.

This spent caustic is further neutralised in CPU pit to pH of 7.0

and pumped to effluent treatment plant.



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

UTILITIES



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

3.1 Cooling Water System

The cooling water in supplied by a dedicated cooling water

tower at OSBL. The cooling water quality supplied has the

following specifications :

pH : 7.2 to 7.8

Total Dissolved Solids Max. 2500 ppm as caco3.

Chlorides Max. 200 ppm as cl.

Silica Max. 100 ppm as S1O2

Free chlorine Max. 0.5 ppm

Turbidty Max. 15 NTV

Total viable count Max. 0.3 million colonies per ml.

Total hardness as Caco3 500 max.

0.P04 6.5-9.0 ppm

T-PO4 9-14

Total FC 3.0 max.

Zinc as Zn 2.0 max.

Corrosion monitoring system is provided at ISBL at the inlet of

E-230 exchangers.

Cooling water supply temperature is 340C. In order to keep the

circumstances to an optimum low quantity. a two level system

with some cooling services operating at an intermediate inlet

temperature of 390C which is known as cooling water tempered CHECKED BY PAGE 88



SECTION MODULE NO.


CKR-PR-P-001

(CWT). The maximum temperature rise through the entire

circuit is 90C. The typical return temperature will be 430C.

The cooling water supply pressure is 5.0 kg/cm2g with a return

pressure of 2.5 kg/cm2g

The cooling tower contains 16 cells and 8 main pumps and two

stand by pumps which supply into the common CWS header of

54” size. Also one more 20” parallel supply header

complements the cooling water supply to tertiary deethanizer.

Auxiliary C4 hydrogenation and propylene fractionation

overhead condensers.

Total of 54000 m3/hr cooling water supply requirement is met

by light pumps running continuously. The preselected three

standby pumps cut in on auto In case of drop in header

pressure to 4.6 kg / cm2g.

There are jumpover from CW supply to CW tempered and CW

supply to CW return to balance the header requirements.

However, these jump over valves are used only during start-up

and remained closed during normal plant running.

Apart from cooling water supply is provided to decoke pot

scrubbing , furnace decoke header injection and pump seal /

hearing house cooling which are routed to OWS system. This is

provided to convert water by reducing service water CHECKED BY PAGE 89



SECTION MODULE NO.


CKR-PR-P-001

requirement and accomplishing cooling tower blowdown which

otherwise it essential at holding tower to maintain circulating

water quality.



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

Cooling Water Balance

Cooling Water User

CWS Header Flow (kg/h) CWT Header Flow (kg/h)

CWR Header Flow (kg/h)

In OutE-320 A-C 1.153.334 1.153.334E-330 A-C 1.119.791 1.119.791E-345 A-D 1.213.325 1.213.325A-101 Note 1 159,120 159,120B-420/421 22,599 22,599BTG-900 102,060 102,060E-900 167,907 167,907E-990 A/B 25,957 25,957E-645 169,180 169,180BTG-600 61,690 61,690E-960 3,790,129 3,790,129E-980 147,654 147,654BTG-650 102,060 102,060B-965 10,633,802 10,633,802BTG-300 92,988 92,988E-930 10,633,802 10,633,802E-981 125,528 125,528E-982 35,456 35,456E-699 A-K 11,562,225 11,562,225E-555 A-H 8,662,000 8,662,000E-556 10,500 10,500E-565 986,800 986,800E-725 864,500 864,500E-736 4,000 4,000E-737 82,500 82,500E-738 (Note 1) 63.648 63,648E-751 154,333 154,333E-755 63,167 63,167E-910 228,000 228,000E-920 436,926 436,926E-735 1,987,400 1,987,400E-273 46,000 46,000B-458 1,033,600 1,033,600E-455 1,090,600 1,090,600E-456 A/B 1,120,200 1,120,200E-521 449,783 449,783E-535 650,000 650,000E-566 513,400 513,400E-711 507,667 507,667E-712 13,000 13,000E-726 30,667 30,667E-732 66,500 66,500E-741 420,333 420,333E-742 5,000 5,000E-802 1,022,824 1,022,824E-803 6,600 6,600E-804 94,964 94,964E-230 A-K 4,198,000 4,198,000E-373 122,960 122,960E-220 A-G 8,436,750 8,436,750E-375 355,212 355,212G-1000 (NOTE 1) 672,000 672,000E-1102 A/B 177,000 177,000E-921 (NOTE 1) 263,543 263,543E-341 355,212 355,212



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

P-900 A-C 33,654 33,654P-901 A/B 716 716P-989 A/B 716 716E-310 A-F 1,693,763 1,693,763E-274 37,700 37,700E-537 747,500 747,500SUB TOTAL 45,225,124 39,850,705 33,803,121 39,177,540BYPASS 6,047,584 6,047,584TOTAL 45,225,124 39,850,705 39,850,705 45,225,124



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

Cooling Water Balance For 700 KTA Expansion Case

ALL FLOWS ARE FROM LATEST ISSUE OF PROCESS DATA SHEETS @ 31 AUG.94 (DESIGN FLOW i.e.NORMAL OPG+ DESIGN MARGIN) PLUS AVAILABLE VENDOR DATACooling Water

UserCWS Header Flow (kg/h) CWT Header Flow

(kg/h)CWR Header Flow

(kg/h)In Out

E-320 A-C 1,291,387 1,291,387E-330 A-C 1,219,203 1,219,203E-345 A-D 1,334,067 1,334,067A-101 Note 1 159,120 159,120B-420/421 22,599 22,599BTG-900 102,060 102,060E-900 167,907 167,907E-990 A/B 25,374 25,374E-645 203,934 203,934BTG-600 61,690 61,690E-960 3,790,129 3,790,129E-980 147,654 147,654BTG-650 102,060 102,060B-965 10,633,802 10,633,802BTG-300 92,988 92,988E-930 10,633,802 10,633,802E-981 125,528 125,528E-982 35,456 35,456E-699 A-K 13,273,629 13,273,629E-555 A-H 9,961,300 9,961,300E-556 11,550 11,550E-565 1,085,480 1,085,480E-725 1,037,400 1,037,400E-736 4,400 4,400E-737 90,750 90,750E-738 (Note 1) 63,648 63,648E-751 169,766 169,766E-755 75,334 75,334E-910 228,000 228,000E-920 480,619 480,619E-735 2,225,888 2,225,888E-273 831,266 831,266E-458 1,136,960 1,136,960E-455 1,199,660 1,199,660E-456 A/B 1,232,220 1,232,220E-521 494,761 494,761E-535 747,500 747,500E-566 564,740 564,740E-711 609,200 609,200E-712 14,300 14,300E-726 33,734 33,734E-732 73,150 73,150E-741 487,586 487,586E-742 5,000 5,000E-802 1,278,530 1,278,530E-803 13,200 13,200E-804 132,000 132,000E-230 A-K 4,198,000 4,198,000E-373 147,552 147,552E-220 A-G 10,602,000 10,602,000E-375 586,100 586,100G-1000 (NOTE 1) 672,000 672,000E-1102 A/B 177,000 177,000



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

E-921 (NOTE 1) 263,543 263,543E-341 565,168 565,168P-900 A-C 33,654 33,654P-901 A/B 716 716P-989 A/B 716 716E-310 A-F 1,836,442 1,836,442E-274 41,470 41,470E-537 747,500 747,500SUB TOTAL 51,613,821 45,738,516 35,968,371 41,843,676BYPASS 9,770,146 9,770,146TOTAL 51,613,821 45,738,516 45,738,516 51,613,821

Notes : 1. Cooling Water flows for E-738, G-1000, A-101 & E-921 are based on Reliance data.

2. Deleted3. Cooling Water flows to analysers, analyser house and pump pedestals

are not included (minimal, typically 1-6 litres/min).



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

3.2 Steam System

The steam system is based on well established principles

developed by S&W. The following sections shall be read with

reference to Utility flow diagram enclosed :

3.2.1 Steam Levels

Five steam levels are employed with the ISBL.

Pressure kg/cm2g Temperature 0CSteam Level

Normal

Min Max. Normal

Min. Max.

SHP Steam 105 102 107 510 480 5100CHP Steam 40 38 42 373 360 400MP Steam 17 15 18 255 235 28LMP Steam 12 11.5 13 260 240 270LLP Steam 3.5 3.0 4.5 187 165

SHP Steam (SH)

SHP Steam is generated in the main and cracking recycle

furnaces is utilised for driving CG Compressor and propylene

refrigeration compressor, along with import steam from OSBL.

SHP Header float with OSBL 105 kg level header. Normally, SHP

to M P let down remains closed and opens only during trip of

any one of the two machines to satisfy HP steam demand. The

import header is sized for 235 TPH.



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

HP Steam (SM)

HP Steam is drawn as extraction from propylene refrigeration

turbine for ISBL requirements. Normally, no import or export of

HP steam taken place. However, the header that with OSBL

header. The header is sized for 60 TPH. Also HP to LMP

letdown closed and opens only during trip of propylene

refrigeration compressor.

MP Steam (SMP)

MP Steam is generated as extractor from cracked gas

compressor turbine. This extraction pressure is selected to float

with OSBL. existing pressure./ the header flats with OSBL

header. Normally, any excess of MP Steam letdown to LMP

steam is exported to OSBL network. However, import of steam

takes place In case of CG Compressor trip beyond the

requirement of letdown from HP to LMP steam.

The import export header is sized for 100 TPH.

MP SteamL (SLM)

LMP Steam steam generated from the letdown of MP steam

during normal operation (or) from HP steam during

emergencies / shutdown. There is nor LMP pressure level OSBL.

There is import / export facility for this steam.



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

LLP Steam (SL)

This steam is imported by letdown of 5.5 kg/cm2g pressure

level at OSBL. to extent of excess requirements of let down

from LMP Level. The import header is sized for 50 TPH.

However, during start-up turndown and upsets two scenario is

different depending on furnaces cracking and running of major

turbine drives.

3.3 Condensate and Boiler feed water system

The cracker plant is self sufficient to handle and recycle all the

steam condenste into the BFW system after treatment. The

facility for condensate, export to OSBL is also provided. For the

net quantity of steam that is reported as there are no facilities

to import condensate, this loss is made up from the import of

DM water.

The Boiler feed water is generated in deaerator from recycling

of clean condensate and by polishing of contaminated

condensate in condensate polishing units. DM water imported

form OSBL is used to make up the loss of steam due to net

export or otherwise and loss of condensate. This steam is

heated and treated to meet boiler feed water for the generation

of steam in furnace steam drums.

Condensate Pressures :

HP Condensate : 37 kg/cm2

LMP Condensate : 10 kg/cm2CHECKED BY PAGE 97



SECTION MODULE NO.


CKR-PR-P-001

LLP Condensate : 2.5 kg/cm2

Condensate system is divided into two subsystems as clean

condensate and support condensate. All high pressure HP, LMP

from user equipment is condensate, flashed in flash drums to

generate steam and the condensate is returned to deaerator

directly as clean condensate.

LLP condensate from user equipments where process side

pressure is higher than the steam pressure is routed to suspect

condensate vessel and subsequently sent to CPU for polishing

or to deaerator through activated carbon filter.

All surface condensate from CGC,C2,C3R turbines are sent to

deaerator after polishing in condensate polishing unit.

During start-up and upset conditions, surface condensate can

be exported to OSBL, before polishing core after polishing.

After deaeration and pH adjustment using ammonia, this is

termed as Boiler, feed water. This BFW is pumped to furnace

steam drums for steam generation for make up in main and

auxiliary dilution steam generation systems and for

desuperheating in SHP to HP letdown system. Two motor driven

and a turbine driven high pressure BFW pumps ate provided

out of which two will be running normally and one motor driven

pump as stand by on auto. In case of pressure drop in HP BFW CHECKED BY PAGE 98



SECTION MODULE NO.


CKR-PR-P-001

header, stand by pump takes auto start to maintain header

pressure.

One LP boiler feed water pump is running to supply water to

desuperheating stations and nominal quantity is exported to

aromatics plant.

3.4 Fuel Gas System:

Cracker Plant is self sufficient of in fuel requirements. All fuel

gas majority methane from demethanise, residue gas from

chilling train and purge gas from PSA unit is mixed in fuel gas

mixing drum and is consumed in main, recycle and GHU

furnaces at 3.5 kg/cm2g pressure.

Excess fuel gas during normal plant operation is exported at

5.5 kg/cm2 g pressure level from the discharge off expander

compressor.

Provision of using C4 raffinate from main and aux. C4

hydrogenation units (or) form OSBL storage is provided as back

up.

Provision of using propane / off .spec propylene from OSBL

storage sphere. propane directly from propylene fracitonator is

also provided.



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

LPG from OSBL LPG bullets can also be routed to fuel gas

system through vaporisers in case of requirement.

Due to various combination of full from methane during normal

operation to C4 raffinate during emergencies, homogeniser

system is provided at the down stream of mixing drum to

adjust density of fuel to furnaces.

Fuel gas is first superheated with LLP steam and LMP steam is

injected superheated in the homogeniser based on the density

of the fuel gas entering the homogeniser.

For initial start-up high pressure of fuel gas form OSBL is

provided as make up into the fuel gas mixing drum.

Design specification of fuel gas

Mole%

C1 92.5%

C2 1.68%

C3 0.1%

CO2 5.7%

H2O 0.01%

H2S 4 PPM mol/mol

Operating pressure : 27 kg/cm2g

Operating temperature : 1300C

Design MW : 17.9CHECKED BY PAGE 100



SECTION MODULE NO.


CKR-PR-P-001

3.5 Nitrogen Process Air, Instrument Air System

3.5.1 Nitrogen

Nitrogen is supplied to cracker at two pressure levels as HP

Nitrogen and LP Nitrogen. This is supplied from air separation

unit.

3.5.1.1 HP Nitrogen

HP Nitrogen is used during start-up as a sealing medium for

compressor during start-up air run. During normal operations.

HP Nitrogen is used in pump seals.

Apart from OSBL import, battery of HP nitrogen cylinders (two

sets) is provided to maintain ISBL header pressure to PMP seals

as back up in case of any drop in OSBL header pressure.

3.5.1.2 LP Nitrogen

LP Nitrogen is used for various services as tank blanketing, seal

gas for ethylene refrigerator compressors and for hose stations

with NRV to cannot to any equipment for purging etc.

Both HP & LP Nitrogen shall be oil free, dew point of -1000C at

atmospheric pressure and max. oxygen gas content of 10 ppm

mol/mol.CHECKED BY PAGE 101



SECTION MODULE NO.


CKR-PR-P-001

Pressure

Normal Min. Max.

HP Nitrogen 30 27 -

LP Nitrogen 7 - 8

3.5.2 Instrument Air

Instrument air is supplied form OSBL by CPP which is

compressed, dried and free of oil. Two parallel headers one at

102 N piperack and other at 105 N pipe rack maintain the

requirement of IA throughout the plant.

Pressure kg/cm2g Temperature (0C) (0C)

Min. Norma

l

Max. Min. Norma

l

Max

4.5 7.0 7.5 30 45 50 -40

3.5.3 Plant Air

Plant air is supplied from OSBL by CPP which is compressed,

saturated to moisture at the supply pressure. The oil content

shall be max. 0.5 ppm wt/wt supply propane. The air is fed from

the hose points to equipments which required deinertisation

etc.

Pressure Temperature

Min. Normal Max. Min. Normal Max.

6.0 7.0 8.0 30 45 50



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

3.6 Service Water System

Service water which is treated raw water is supplied by CPP to

OSBL which is used as service water at hose stations for

washing etc. and an drinking water at control room,

changerooms and yard toilet. Also this water is supplied to

laboratory for cleaning, washing etc.

Specifications for Service Water

pH : 7.8

Thurbidity : 2 NTV

Chloride : 32 ppm as cl.

Sulphate : 35 ppm as SO4

P-Alkalinity : Nil

M-Alkalinity : 187 as Ca CO3 ppm

Total Anions : 269 as Ca CO3 ppm

Total Hardness : 134 as Ca CO3 ppm

Magnesium Hardness : 62 as Ca CO3 ppm

Sodium : 135 as Ca CO3 ppm

Total Cations : 269 as Ca CO3 ppm

Total Silica : 10 as SiO2 ppm

Collected silica : 0.2 as S1O2 ppm

Total iron : 0.5 as FE ppm

Total Dissolved solids : 170 ppm



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

3.7 DM Water system

DM water is imported from CPP at a maximum peak flow rate of

250 m3/hr during start-up and upsets. DM water is received in

DM water storage tank and pumped to deaerator as make-ups.

Also provision is provided for make up into quench water tower

for make up. during upsets / start-up, DM water consumption is

minimised by recycling the condensate from various system.

DM water from OSBL has the following specifications :

pH : 6.5 to 7.0

Total dissolved solids : 0.5 ppm

Total hardness : Nil

Chlorides : Nil

Iron : .005 ppm as FE

Electricity conductivity : 0.2 ms/cm

Total silica : 0.02 as SiO2 ppm

Sodium : Nil

Colour : Colourless



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

3.8 Fire water system

Fire water is received from the hydrant header surrounding the

plant ISBL from OSBL fire water system. Every area is provided

with divide headed fire hydrant points with fire hose box

adjacent to them. Each hydrant point has an isolation valve and

hydrant points (single) on the structures has been provided

with common isolation valve at grade. Apart from hydrant

points, on line water monitors are provided at strategic

locations. Quench fittings on main and recycle furnaces are

provided with manual deluge system to be care of any fire

emergency at this locations.

Headers in each area of the plant can be isolated by closing

slice valves provided at both the ends of the network. (Refer

enclosed singe line sketch).



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

3.9 ELECTRIC POWER SYSTEM :

Electrical power at 33 KV, 50 Hz for start-up and normal operations shall

be available from the OSBL central electrical power handling facility at the

battery limit.

The electrical power system is characterised as follows :

Particulars Specification Suggested Users

A Frequency of all AC power supply

50 HZ # 3%

B Electrical Power Generation :Emergency Generator :TypeVoltage Level

AC 3 phase415 V # 6%

C Primary Distribution in OSBL:TypeVoltage Level

AC, 3 phase33 KV # 5%

D DC Power supply system: Voltage Level a)

b)

c)

220 V + 10%, -20%

110 V + 10%, -20%

24 V DC

Critical lighting control supply for circuit breakers, alarm annunciators.

Shutdown system (all solenoid valves) in existing plant area.

Relay logic, switches, solenoid valves in ISBL.

E Other AC Power Supply System :a) Type

Voltage LevelAC 3 phase6.6 KV # 6%

Motor drives above 160 KW

b TypeVoltage Level

AC, 3 phase415 V # 6%

Motor drives(0.18 KW to 160 KW, lighting, welding machine, overhead crane.

c TypeVoltage Level

AC 1 phase240 V # 6%

Motor drives below 0.18 KW & control supply for 415 V motor contactor, instrument cabinet lighting, hand lamp socket, portable tools, motor panel / space heater, plant communication, fire alarm, level gauge illumination.

d TypeVoltage Level AC, 1 phase



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

UPS basedNon UPS

110 V # 2%110 V # 5%

All instrument, DCS

e TypeVoltage Level

AC, 1 phase24 V # 6%

For handheld / portable lighting

UTILITY CONDITIONS AT BATTERY LIMIT

ALL STREAM PRESSURE SHALL BE CONSIDERED AS AT GRADE LEVEL :

Sl. Particulars Unit Operating Conditions Design

Minimum Normal Maximu

m

A SHP SteamPressureTemperature

kg/cm2gC

102485

105500

107510

112 (4)510

B HP Steam :Pressuretemperature

kg/cm2gC

38360

40373

42400

47420

C HP Steam (Import):PressureTemperature

kg/cm2gC

15235

17245

18280

22350

D LMP Steam (Export):PressureTemperature

kg/cm2gC

11.5240

12260

13270

15300

E LP Steam (Import):PressureTemperature

kg/cm2gC

4160

4.5170

5.5200

8.1270

F LLP Steam (Export):PressureTemperature

kg/cm2gC

3.0165

3.5187

4.5 (4) 6.5250

G Steam Condensate (Export):Pressure (note-3)Temperature

kg/cm2gC

3AMB

4.5AMB

17.965

H Instrument Air :PressureTemperature

kg/cm2gC

430

6.545

7.550

10.565

I Plant AirPressureTemperature

kg/cm2gC

430

7.045

7.550

10.565

J LP Nitrogen Gas:PressureTemperature

kg/cm2gC

7Ambient

8Ambient

9 10.565

K HP Nitrogen Gas:PressureTemperature

kg/cm2gC

30Ambient

32Ambient

33Ambient

4065

L Service WaterPressureTemperature

kg/cm2gC

4 Ambient

5.5Ambient

7Ambient

1065

M Fire Water:



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

PressureTemperature

kg/cm2gC

10Ambient

1265

N Cooling WaterSupply PressureSupply Temperature

Return PressureReturn Temperature

kg/cm2gC

kg/cm2gC

4.0Ambient

534

2.543

634

8.065

8.065

O Demineralized (DM) Water:PressureTemperature

kg/cm2gC

5Ambient

7.5Ambient

1065

P Drinking WaterPressureTemperature

kg/cm2gC

0.5Ambient

1Ambient

3.0 5.065

Q LP Boiler Feed Water:PressureTemperature

kg/cm2gC

21.2115

33.517.0



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

EFFLUENTS



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

4.0 Plant effluents and Disposal Methods:

Due to complex nature of operations, a variety of solid,

gaseous and liquid effluents are obtained form the gas cracker

plant. This is intended that all operating personnel shall take all

necessary measures to minimise effluents generation.

4.1 Solid effluents:

Coke:

Coke is the solid waste product obtained during decoking

operation from the decoke pots and during hydrojetting of USX

and collection headers. This is being disposed off to OSBL as

land fill.

By the addition of DMDS to the feed of cracking main and

recycle furnaces, this coke formation is minimised.

4.2Gaseous effluents :

Flue Gases :

There are produced in cracking furnaces and in GHU furnaces

which are released to atmosphere continuous. The quality of

this effluent from cracking furnace is continuously monitored

by one line CO and O2 analysers. Also, complete emission

constituents are analysed by central environmental monitoring

cell to ensure adherence to local statutory requirements.

Gases Hydrocarbons



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

During normal operation, no gases effluents are produced as

most all of the vent gases are recycled into the process system

for recovery. Few discharges as GHU stripper vent and spent

caustic oxidation stripper vents are routed into flare system

where they are flared at 110 M high level. For the completion of

combustion, steam is injected into the flare system. Also,

hydrocarbon vent during unit upset is routed to flare stack for

complete combustion and safe disposal.

4.3Liquid Effluents :

Storm Water :

Water during rains is collected in the ISBL by means of catch

pits and are routed to two storm water walls, located at north

and south side of the plants with slice gate to stop flow into the

storm water channel.

During normal season, the water collected into these walls from

fire water drain, boiler drum CBD, decoke pot drain and steam

condensate drains are pumped to effluent treatment plant for

suitable treatment and disposal.

During monsoon, water collected in these walls overflow into

the storm water channel and are disposed into Tapi River

entry.

Oily water sewer :CHECKED BY PAGE 111



SECTION MODULE NO.


CKR-PR-P-001

Water containing traces are hydrocarbon, seal cooling liquid

form pump seals, dil. steam generation blowdown, suspect

condensate drain, and other process aqueous plant drain are

collected into OWS well via hubs connected to underground

closed piping system. This is pumped to effluent treatment

plant for suitable treatment and disposal.

Spent Caustic Effluent :

Spent Caustic from Caustic Tower after treatment with gasoline

and additives is pumped to spent caustic oxidation unit where

COD and sulfur content is reduced to the great extent. Also,

stripper provided at the upstream of spent caustic oxidation

unit removes aromatic components. Thus this effluent is

neutralised with hydrochloric acid to pit of 7.0 and pumped to

effluent treatment plant for disposal.

CPU regeneration waste :

Regeneration water effluent from condensate polishing unit is

mixed along with SCO effluent and neutralised to pH 7.0 and

sent to ETP for disposal.

Quench oil sewer :

All heavy oil drains in the prefractionation area is collected in a

hubs which are connected to double pipe underground network

to drain drum. From the drain drum it is recycle back into

quench oil tower or can be sent to OSBL storage tanks.CHECKED BY PAGE 112



SECTION MODULE NO.


CKR-PR-P-001

EMERGENCIES



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

5.0 Emergency Shutdown

In all cases of emergency, the Operator in charge shall exercise

his discretion regarding shutdown, bearing in mind :

a) The safety of Personnel

b) The safety of equipment

Failure of an individual pumping unit, where a standby unit is

available for immediate service; individual instrument, failure,

where bypass or direct manual control (handjack) is available,

and similar isolated or individual failures must not be treated as

requiring emergency shutdown. Momentary failure of any utility

should be treated as a temporary emergency and any tripped

equipment or its standby unit must be commissioned, as

quickly as possible.

quench oil failure must not be treated as requiring emergency

shutdown. Quenching of the furnace effluent is automatically

continued by naphtha. Continue operation unit it is obvious that

oil circulation can't be restored and a planned shutdown is then

carried out. Shutdown of the furnaces should be undertaken if

the base liquid level of the quench oil tower, C-210, approaches

the transfer line inlet nozzle elevation and disposal of quench

oil continues to be a problem. If quenching of the furnace

effluent is insufficient for any reason, hydrocarbon feed should

be taken out of the furnaces. If a compressor should trip due to CHECKED BY PAGE 114



SECTION MODULE NO.


CKR-PR-P-001

an in-built safety system, the fault should be cleared before

restart; trips must not be overridden. The extent to which the

furnaces are kept on line during such an emergency will

depend upon individual circumstances but there should be

normally no necessity to use an emergency trip on the

furnaces.

The trip of any system, and in particular the reactor systems,

must be thoroughly investigated before attempting to bring

them back into operation. Again no emergency trip of any other

equipment should be necessary in this case.

Emergency shutdowns will be carried out for the following

events :

1. Total and sustained electric power failure

2. Total and sustained cooling water failure.

3. Total and sustained instrument air failure

4. Loss of steam pressure

5. Uncomfortable leakage of hydrocarbons

6. Serious and uncontrollable fire.

The P&I diagrams show the major automatic alarm and

shutdown systems included in the plant. SOP must be

consulted as necessary for detailed operation.



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

Electric Power Failure

A sustained power failure is regarded as a remote possibility

but would however result in the shutdown of :

-furnaces, due to induced draft fan failure (SD-2

-pumps and normal plant lighting

Motor driven compressors

Actions to be taken if Power is not Immediately Restored:

a) Block off all hydrogen supply to the C2 Hydrogenation

Reactors, depressurise the reactors and nitrogen and

nitrogen purge. Block in regeneration air flow if any is being

used. Refer to the IFP Operating Manuals for information on

handling the C3,C4 Gasoline Hydrogenation units.

b) Close cracking furnace burner cocks, block in hydrocarbon

fuel supply, close dampers to reduce rate of refractory

cooling. Close decoking air if any was used. Try to maintain

dilution steam to furnaces as long as is necessary to purge

coils.

c) If available, continue cooling water flows to all units. Release

excessive pressures in equipments to the flare, using safety

valve bypass valves, or depressurization control valves, in

preference to allowing the safety valves to lift and possibly

not reset.

d) Block in cracked gas dehydrators, take note of regeneration

status when blocking in regeneration lines.



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

e) Shut off heating medium to fractionation tower reboilers at

control valves and / or block valves.

f) Isolate the various refrigeration stages by block valves to

prevent pressure migration, if it is decided to shutdown the

compressors.

g) Reduce liquid levels in towers and drums to near normal, by

either pressuring to the next process sequence or to

blowdown drums, the choice being dependent upon

circumstances. In general, where a restart after an

emergency shutdown is anticipated fairly soon, levels should

be maintained at the optimum to facilitate the restart.

h) Equipment should be shutdown and shut in as far as possible

by means of control room instruments, particular attention

being paid to equipment pressures.

Cooling Water Failure

Cooling Water failure will automatically trip all USC and Recycle

furnaces to SD-2

-CG Compressor

-C2 Hydrogenation unit on offspec.

Actions to be taken at a Sustained Water Failure

a) Block in furnaces as under 9.2.1(b)

b) Stop electrically driven process compressors (B-740 A/B) and

block in.

c) Stop all heating media to reboilers.



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

d) Remove hydrogen from reactors and block in as under 9.21.

(a)

e) Stop charge pumps, stop reflux pumps as reflux drum levels

drop.

f) On a system by system basis release excessive pressures in

equipment to the flare only when required, using safety

valve bypass valves or drpressurization control valves, in

preference to allowing the safety valves to lift and possibly

not reset. Great care must be taken not to overload the flare

relief system by dumping large relief loads simultaneously.

g) Reduce liquid levels in towers and drums to near normal by

either pressuring to the next process sequence or to

blowdown drums, the choice being dependent upon

circumstances. In general, where a restart after an

emergency shutdown is anticipated fairly soon, levels should

be maintained at the optimum, to facilitate the restart.

h) Equipment should be shutdown and shut in as far as

possible, by means of the control room instruments,

particular attention being paid to equipment pressures.

i) Stop the pumping of fresh caustic solution to the caustic

wash tower.

j) Stop the injection of DMDS to the Furnaces and shutdown all

other process chemicals injection systems.

k) Stop all product withdrawal

Instrument Air Failure



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

Air failure would be result in the failure of activating air to

control valves. the instrument design of the plant is such that

the valves move to put the plant in the safest possible

condition under the circumstances.

Action to be taken on a General Instrument Air Failure

All automatic valves will have gone to the fail-safe position,

block valves on the following systems should also be closed to

make doubly sure of safe conditions.

a) Block off hydrogen to all reactors, proceed as under 9.2.1(a).

b) Shutdown furnaces as under 9.2.1(b).

c) block in compressors and refrigeration system.

d) Block in cracked gas dehydrators as under 9.2.1(d).

e) Isolate the various refrigeration stages to prevent pressure

migration.

f) Block off heating medium to reboilers, preheaters, etc.

g) Reduce liquid levels in towers drums to normal working

levels by use of control valve bypasses pressuring to the

next process sequence or the blowdown drum, maintaining

adequate levels to facilitate the starting operation.

Loss of steam pressure

Dependent upon the steam main involved various emergencies

could occur and the senior operator will need to exercise his

discretion upon the appropriate action to be taken. IN all cases

every effort must be made to continue dilution steam flows to



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

the cracking furnaces until all hydrocarbon materials are

purged out.

Action to be taken

a) Conserve the dilution steam main pressure as long as

possible, reducing higher pressure steam consumption

wherever possible.

b) Activate shutdown 1 on all furnaces. This will cut out furnace

feed, add dilution steam to the hydrocarbon coils and cut

60% of the heat input to the furnaces.

c) If dilution steam failure is imminent, activate shutdown 2 on

all furnaces. In addition to the SD-1 trips, this will cut out all

gas burners and after a short purge period, shut off the

dilution steam flow.

It is possible that furnaces which suffer dilution steam failure

before the short purge period will require decoking before the

next start-up.

d) If the S-105 steam supply pressure falls, stop the cracked

gas compressor to maintain the Refrigeration Compressors

in service if required depending on the steam demand at low

levels.

NOTE : When intending to shutdown furnaces or any other

equipment in an emergency situation, do not proceed by an

indirect route, i.e. making a process alteration which will in

normal sequence lead to the desired shutdown action.CHECKED BY PAGE 120



SECTION MODULE NO.


CKR-PR-P-001

If shutdown 1 or 2 on the furnaces is called, for, activate the

switches provided, checking that all furnace conditions proceed

thereby to the desired safe condition.



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

Uncontrollable Leakage and Fire

Actions to be taken at the occurrence of a large leakage or fire

will obviously depend upon the location of the fire, the

proximity of other inflammable materials and numerous other

variables. Company standard fire drill procedures should be

followed while the plant is being shutdown in as orderly a

manner as possible, extinguishing all furnace burners as

quickly as possible, stopping fans and closing furnace stack

dampers, isolating the burning equipment and cutting off

supplies of inflammable material to the source of the fire.

Motor operated isolation valves are installed on the common

suction lines to all hydrocarbon pumps and are also installed on

the first stage suction, third stage discharge, and the fourth

stage suction and discharge of the cracked gas compressor,

and the suction and discharge of all stages of the propylene

and ethylene refrigerant compressors, and also major product

streams. All these valves are operable from the field so that

easier isolation can be achieved. In the case of pumps, the

pump motor is tripped when the remote isolation switch is

activated. Snuffing steam purges to pump seals are provided

with remote field valves.

During any plant emergency or normal shutdown, the

containment of gaseous and liquid hydrocarbons with

controlled release to the flare and blowdown must be enforced.

Inflammable liquids accidentally entering surface drainage CHECKED BY PAGE 122



SECTION MODULE NO.


CKR-PR-P-001

systems and hydrocarbon vapours can lead to hazardous

conditions or an increase in an existing conflagration.



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

EQUIPMENT LIST



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

6.0 Equipment List

Section Title1 BUILDINGS2 ROTATING EQUIPMENTS3 TOWERS4 EXCHANGERS5 GENERAL EQUIPMENT6 FURNACES7 PUMPS8 REACTORS9 TANKS10 DRUMS

BUILDINGS

ITEM NO. DESCRIPTION

A 003 Mechanical Workshop/Dining RoomA 004 HVAC Chilling Unit Compressor HouseA 101 MCC & Control houseA 105 Gas Turbine Control HouseA 110 Furnace Analyser Shelter No.1A 120 Furnace Analyser Shelter No.2A 301 Cracker Gas Compressor ShelterA 401 Methane Compressor ShelterA 410 Cold Fractionation Analyser Shelter

No.1A 450 Cold Fractionation Analyser No.2A 510 Warm Fractionation Analyser ShelterA 601 Refrigeration Compressor ShelterA 701 G.H.U. Compressor ShelterA 901 Fuel Gas Compressor Shelter



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

ROTATING EQUIPMENT

ITEM NO.

QTY. DESCRIPTION

B 100 1 Gas TurbineB 101 A/B 2 FD Fan (Motor Driven)B 102 1 FD Fan (Motor Driven)B 103 1 GT Fuel gas CompressorB 110 1 ID Fan (USC Furnace)B 111 1 ID Fan (USC Recycle Furnace)B 120 1 ID Fan (USC Furnace)B 121 1 ID Fan (USC Recycle Furnace)B 130 1 ID Fan (USC Furnace)B 131 1 ID Fan (USC Recycle Furnace)B 140 1 ID Fan (USC Furnace)B 150 1 ID Fan (USC Furnace)B 160 1 ID Fan (USC Furnace)B 170 1 ID Fan (USC Furnace)B 180 1 ID Fan (USC Furnace)B 190 1 ID Fan (USC Furnace)B 192 1 ID Fan (USC Furnace)B 194 1 ID Fan (USC Furnace)B 196 1 ID Fan (USC Furnace)B 300 1 Cracked Gas CompressorB 420 1 Methane RecompressorB 421 1 Methane ExpanderB 600 1 Ethylene Refrigerant CompressorB 650 1 Propylene Refrigerant CompressorB 710 A/B 2 1st Stage Make-up and Recycle CompressorB 740 A/B 2 2nd Stage Make-up and Recycle CompressorB 900 1 Fuel Gas CompressorB 915 1 Polisher Air BlowerB 1101 A/B 2 High Pressure Air CompressorsB 1121 A/B/C 3 SCO Reactor Feed Air CompressorBT 102 1 FD Fan TurbineBT 300 1 Cracked Gas Compressor TurbineBT 600 1 Ethylene Refrigerant Compressor TurbineBT 650 1 Propylene Refrigerant Compressor TurbineBT 900 1 Fuel Gas Compressor Turbine



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

TOWERS

ITEM NO.

QTY. DESCRIPTION

C 210 1 Quench Oil TowerC 220 1 Quench Water TowerC 230 1 Heavy Fuel Oil StripperC 240 1 Light Fuel Oil StripperC 250 1 Distillate StripperC 260 1 LP Water StripperC 270 1 Dilution Steam StripperC 280 1 Auxiliary Dilution Steam StripperC 340 1 Caustic TowerC 350 1 Cracked Gas RectifierC 360 1 Condensate StripperC 410 1 Demethanizer PrestripperC 420 1 DemethanizerC 430 1 Residue Gas RectifierC 440 1 DeethanizerC 460 1 Ethylene StripperC 470 1 Ethylene RectifierC 510 1 DepropanizerC 530 1 Secondary DeethanizerC 535 1 Tertiary DeethanizerC 540 1 Propylene StripperC 550 1 Propylene RectifierC 560 1 DebutanizerC 720 1 DepentanizerC 730 1 DeoctanizerC 750 1 StripperC 1101 1 Steam Stripper



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

EXCHANGERS

ITEM NO.

QTY. DESCRIPTION

E011 1 Ethane/Propane Recycle HeaterE 041 1 Naphtha Feed HeaterE 051 A/B 2 AGO Feed HeaterE 052 1 AGO Feed Heater No.2E053 1 AGO Feed Heater No.3E 110 A/H, J/Q 16 USX Exchanger (USC Fresh Feed Furn.)E 111 1 TLX Exchanger (USC Fresh Feed Furn.)E 115 A/D 4 USX Exchanger (USC Fresh Feed Furn.)E 120 A/H, J/Q 16 USX Exchanger (USC Fresh Feed Furn.)E 121 1 TLX Exchanger (USC Fresh Feed Furn.)E 125 A/D 4 USX Exchanger (USC Fresh Feed Furn.)E 130 A/H, J/Q 16 USX Exchanger (USC Fresh Feed Furn.)E 131 1 TLX Exchanger (USC Fresh Feed Furn.)E 135 A/D 4 USX Exchanger (USC Fresh Feed Furn.)E 140 A/H, J/Q 16 USX Exchanger (USC Fresh Feed Furn.)E 141 1 TLX Exchanger (USC Fresh Feed Furn.)E 150 A/H, J/Q 16 USX Exchanger (USC Fresh Feed Furn.)E 151 1 TLX Exchanger (USC Fresh Feed Furn.)E 160, A/H, J/Q 16 USX Exchanger (USC Fresh Feed Furn.)E 161 1 TLX Exchanger (USC Fresh Feed Furn.)E 170 A/H, J/Q 16 USX Exchanger (USC Fresh Feed Furn.)E 171 1 TLX Exchanger (USC Fresh Feed Furn.)E 180 A/H, J/Q 16 USX Exchanger (USC Fresh Feed Furn.)E181 1 TLX Exchanger (USC Fresh Feed Furn.)E 190 A/H, J/Q 16 USX Exchanger (USC Fresh Feed Furn.)E 191 1 TLX Exchanger (USC Fresh Feed Furn.)E 192 A/H, J/Q 16 USX Exchanger (USC Fresh Feed Furn.)E 193 1 TLX Exchanger (USC Fresh Feed Furn.)E 194 A/H, J/Q 16 USX Exchanger (USC Fresh Feed Furn.)E 195 1 TLX Exchanger (USC Fresh Feed Furn.)E 196 A/H, J/Q 16 USX Exchanger (USC Fresh Feed Furn.)E 197 1 TLX Exchanger (USC Fresh Feed Furn.)E 210 A/C 3 Fuel Oil Product CoolerE 215 A/B 2 Quench Water Steam HeaterE 219 1 Pan Oil Trim CoolerE 220 A/G 7 Primary quench water coolerE 230 A/H, J/K 10 Secondary quench water coolerE 239 1 LFO Stripping Steam Superheater



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

ITEM NO.

QTY. DESCRIPTION

E 250 1 Distillate Stripper ReboilerE 258 1 Water Stripper Feed HeaterE 259 1 DSS Bd./Water Stripper Feed HeaterE 265 A/B 2 DSS Feed Heater No.1E 269 1 DSS Feed Heater No.2E 270 A/D 4 DSS Steam ReboilerE 271 A/H 8 DSS Q.O. ReboilerE 273 1 DSS Blowdown CoolerE 274 1 Auxiliary Dilution Steam Stripper Blowdown CoolerE 279 1 Aux. Dilution Steam Stripper Feed HeaterE 280 A/C 3 Aux. Dilution Steam Stripper ReboilerE 310 A/C 6 C.G. First Stage AftercoolerE 310 A/F 3 C.G. Second Stage AftercoolerE 320 A/C 3 C,G. Third Stage AftercoolerE 330 A/C 1 Weak Caustic HeaterE 340 1 Wash Water CoolerE 341 4 C.G. Fourth Stage AftercoolerE 345 A/D 1 C.G. Rectifier Overhead CondenserE 355 1 Condensate Stripper Feed HeaterE 359 2 Condensate Stripper ReboilerE 360 A/B 1 Condensate Stripper ReboilerE 371 1 React. Gas Feed / Effluent ExchangerE 372 1 React. Gas Feed HeaterE 373 1 Reactivation Gas Feed CoolerE 374 1 Reactivation Gas Feed ChillerE 375 1 Reactivation Gas Effluent CoolerE 401 1 Demethanizer Precooler No.1E 402 1 Demethanizer Precooler No.2E 403 1 Demethanizer Precooler No.3E 404 1 Demethanizer Precooler No.4E 405 1 Demethanizer Precooler No.5E 406 1 Demethanizer Precooler No.6E 407 1 Demethanizer Parallel Precooler No.1E 408 1 Demethanizer Parallel BTMS ReheaterE 409 1 Demethanizer Parallel Precooler No.2E 410 1 Demethanizer Prestripper ReboilerE 411 1 Demethanizer Core Exchanger No.1E 412 1 Demethanizer Core Exchanger No.2E 413 1 Demethanizer Core Exchanger No.3E 414 1 Demethanizer Core Exchanger No.4E 415 1 Demethanizer Core Exchanger No.5E 419 1 Hydrogen Core ExchangerE 420 1 Demethanizer ReboilerE 421 1 Demethanizer Parallel Precooler No.3E 422 1 Demethanizer Parallel Precooler No.4



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

EXCHANGERS

ITEM NO.

QTY. DESCRIPTION

E 424 1 Demethanizer Precooler No.6E 425 1 Demethanizer CondenserE 426 1 Methane Product HeaterE 427 1 Methane Product HeaterE 438 1 Demethanizer Bottoms ReheaterE 439 A/B 2 Demethanizer, Prestripper Btms ReheaterE 440 A/C 3 Deethanizer ReboilerE 445 A/D 4 Deethanizer CondenserE 450 1 C2 Hydrog. Feed HeaterE 452 A/D 4 C2 Hydrog. Feed / Effluent ExchangerE 455 1 C2 Hydrog. Adia. Rct. Intercooler No.2E 456 A/B 2 C2 Hydrog. Adia. Rct. AftercoolerE 458 1 C2 Hydrog. Adia. Rct. Intercooler No.1E 460 1 Ethylene Stripper ReboilerE 461 1 Ethylene Recycle Vaporiser E 470 A/B 2 Ethylene Rectifier ReboilerE 475 A/D 4 Ethylene Rectifier CondenserE 477 1 Ethylene Product VaporiserE 478 1 Ethylene Product SuperheaterE 480 1 Ethylene Product Cooler No.1E 481 1 Ethylene Product Cooler No.2E 482 1 Ethylene Product Cooler No.3E 490 1 HP Ethylene Product Heater No.1E 491 A/B 1 HP Ethylene Product Heater No.2E 510 A/B 2 Depropanizer ReboilerE 515 A/B 2 Depropanizer CondenserE 521 1 Interstage CoolerE 522 1 Catalyst TreatmentE 530 1 Secondary Deethanizer ReboilerE 535 1 Secondary Deethanizer CondenserE 536 1 Tertiary Deethanizer ReboilerE 537 1 Tertiary Deethanizer CondenserE 540 A/D 4 Propylene Tower ReboilerE 541 A/B 2 Propylene Tower Aux. ReboilerE 542 1 Propane Recycle VaporiserE 555 A/H 8 Propylene Tower CondenserE 556 1 Propylene Product CoolerE 560 A/B 2 Debutanizer ReboilerE 565 1 Debutanizer CondenserE 566 1 Pyrolysis Gasoline Product CoolerE 645 1 C2 Refrigerant Desuperheater No.1



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

EXCHANGERS

ITEM NO.

QTY. DESCRIPTION

E 646 1 C2 Refrigerant Desuperheater No.2 E 647 1 C2 Refrigerant Desuperheater No.3E 649 A/B 2 Aux. C2 Refrigerant CondenserE 650 1 C2 Refrigerant SubcoolerE 695 1 C3 Refrigerant DesuperheaterE 699 A/H, J/K 10 C3 Refrigerant CondenserE 701 1 1t Stage Reactor Feed/Effl. ExchangerE 702 1 1st Stage Reactor Start-up HeaterE 711 1 1st Stage Quench CoolerE 712 1 Hot Separator Vapour CondenserE 713 1 1st Stage Compressor Bypass CoolerE 720 1 Depentanizer CondenserE 725 1 Depentanizer CondenserE 726 1 C5 Product CoolerE 730 A/B 2 Deoctanizer ReboilerE 731 1 Wash Oil Condenser E 732 1 Deoctanizer Bottoms CoolerE 735 1 Deoctanizer CondenserE 736 1 Decoct Post Condenser CoolerE 737 1 Wash Oil Trim CoolerE 738 1 Ejector CondenserE 740 A/B 5 2nd stage Feed / Effluent ExchangerE 741 1 2nd stage Reactor Effluent CoolerE 742 1 2nd stage Compressor Bypass CoolerE 749 A/B 2 Stripper Feed / Effluent ExchangerE 750 1 Stripper ReboilerE 751 1 C6-C8 Product Trim CoolerE 755 1 Stripper CondenserE 801 1 Reactor start-up heaterE 802 1 Recycle CoolerE 803 1 Post CondenserE 804 1 Product CoolerE 805 1 C4H Startup Heater (Unit-2)E 806 1 C4H Recycle Cooler (Unit-2)E 807 1 C4H Postcondensor (Unit-2)E 808 1 C4H Product Cooler (Unit-2)E 900 1 Fuel Gas Compressor Recycle CoolerE 902 1 Cold Blowdown VaporiserE 903 1 C5 Fuel VaporiserE 904 1 Suspect Cond. Drum vent CondenserE 905 1 C3/C4 Fuel VaporiserE 906 1 Fuel gas SuperheaterE 907 1 Methanol VaporiserE 909 1 Cold Flare Superheater



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

EXCHANGERS

ITEM NO.

QTY. DESCRIPTION

E 910 1 Knock-out Drum Slops CoolerE 920 1 Contaminated Condensate CoolerE 921 1 Condensate Polisher Inlet CoolerE 922 1 CPU Effluent Heat ExchangerE 930 1 C.G. Comp. Steam Turbine CondenserE 938 1 Ejector CondenserE 960 1 C2 Refrig. Comp. Steam Turb CondenserE 961 1 Z-960 Ejector CondenserE 965 1 C3 Refrig. Comp. Steam Turb CondenserE 966 1 Z-965 Ejector CondenserE 980 1 C2/C3 Refrig. Compressor Lube/Seal Oil CoolerE 981 1 CG Compressor Lube Oil CoolerE 982 1 Cg Compressor Seal Oil CoolerE 990 A/B 2 Fuel Gas Compressor Lube / Seal Oil CoolerE 1101 1 Steam Stripper Feed Pre-heaterE 1102 A/B 1 Steam Stripper Effluent CoolerE 1103 1 Influent / Effluent Heat ExchangerE 1104 1 Oxidation Reactor Effluent CoolerE 1105 1 SCO Treated Effluent CoolerE 1121 1 SCO Effluent CoolerE 1122 1 SCO Feed / Vent Gas ExchangerE 1123 1 SCO Vent Gas Cooler



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

GENERAL EQUIPMENT:ITEM NO.

QTY. DESCRIPTION

BG 300 1 Turning Gear MotorBG 650BL 300 1 CG Compressor Lube Oil ConsoleBL 650 1 E 650 & E 600 LO/SO ConsoleBL 900 1 FG Compressor LO/SO ConsoleBS 300 1 CG Compressor Seal Oil ConsoleBTG 300 1 CG Compressor Gland Stm Ejector PkgBTG 600 1 C2 Refrig. Comp. Gland Stm. Ejector PkgBTG 650 1 C3 Refrig Comp Gland Stm. Ejector PkgBTG 900 1 Fuel Gas Comp Gland Stm Ejector PkgG 101 1 Main Control Room HVAC PackageG 711 1 Polymerisation Inhibitor Package

Including : T-711, Z-711, P-711 A-DG 736 1 Deoctanizer Ejector SystemG 742 1 DMDS Injection Package

Including: P-742G 752 1 Corrosion Inhibitor Injection Package

Including : T-752, Z-752, P-752G 981 1 Phosphate Injection Package

Including : T-981, Z-981, P-981 A/CG 982 1 Hydazine Injection Package

Including: T-982, Z-982, P-982 A/BG 986 1 DMDS Injection Package

Including : T-986, P-986 A/B, P-995 A/DG 987 1 Corrosion Inhibitor Package

Including: T-987. Z-987, P-987 A/BG 988 1 Defoaming : T-987, Z-987, P-987 A/B

Including : T-988, Z-988, P-988 A/BG 1000 1 Spent Caustic Oxidation UnitZ 110 1 Quench Fitting (USC Furnace)Z 111 1 Quench Fitting (USC Recycle Furnace)Z 120 1 Quench Fitting (USC Furnace)Z 121 1 Quench Fitting (USC Recycle Furnace)Z 130 1 Quench Fitting (USC Recycle Furnace)Z 131 1 Quench Fitting (USC Furnace)Z 140 1 Quench Fitting (USC Furnace)Z 150 1 Quench Fitting (USC Furnace)Z 160 1 Quench Fitting (USC Furnace)Z 170 1 Quench Fitting (USC Furnace)Z 180 1 Quench Fitting (USC Furnace)Z 190 1 Quench Fitting (USC Furnace)Z 192 1 Quench Fitting (USC Furnace)Z 194 1 Quench Fitting (USC Furnace)Z 196 1 Quench Fitting (USC Furnace)Z 210 A/B 1 Quench Oil Filters



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

GENERAL EQUIPMENT

ITEM NO.

QTY. DESCRIPTION

Z 230 A/B 2 Heavy Fuel Oil FilterZ 261 A/B 2 Water Stripper feed FiltersZ 300 1 Oil PurifierZ 301 1 Cracked Gas Compressor Service CraneZ 320 1 Vane Separator for 2nd stage suction drumZ 330 1 Vane Separator for 3rd stage Suction DrumZ 335 1 Vane Separator for 3rd stage suction drumZ 340 1 Vane separator for 4th Stage Suction DrumZ 341 1 Caustic Diluent MixerZ 342 1 Week Caustic Circ. Pump Suction StrainerZ 343 1 Spent Caustic / Aromatic Gasoline MixerZ 344 1 Caustic Area SumpZ 400 1 Pressure Swing Adsorption UnitZ 401 1 Methane Comp. Service CraneZ 601 1 Main Compressor Service CraneZ 602 1 Ethylene Compressor Service CraneZ 610 A/B 1 Ethylene Refrigerant Oil FiltersZ 611 1 Vane Separator for C2R 1st Stage Suction DrumZ 660 1 Vane Separator for C3R 1st Stage Suction DrumZ 690 1 Vane Separator for C3R 4th Stage Flash DrumZ 701 1 GHU Compressor Service CraneZ 702 A/B 2 RPG Feed FiltersZ 711 1 Polymerisation Inhibitor MixerZ 736 1 Deoctanizer Ejector SystemZ 740 1 2nd stage ejectorZ 752 1 Corrosion Inhibitor MixerZ 900 1 Condensate PolisherZ 901 A/B 2 S40 DesuperheaterZ 902 A/B 2 S12 DesuperheaterZ 903 A/B 2 S3.5 DesuperheaterZ 904 A/B 2 Suspect Condensate FiltersZ 905 1 GHU Reboiler Steam DesuperheaterZ 906 1 SMP Extraction Steam DesuperheaterZ 910 1 Flare System (outside Battery Limits of Cracker)Z 914 1 Polisher Acid Tank AgitatorZ 930 1 CG Compressor Turbine Ejector PackageZ 960 1 C2 refrig Compressor Turbine Ejector PkgZ 965 1 C3 refrig compressor Turbine Ejector PkgZ 981 1 Phosphate tank AgitatorZ 982 1 Hydrazine Tank AgitatorZ 987 1 Corrosion Inhibitor Tank AgitatorZ 988 1 Defoaming Agent Tank AgitatorZ 990 1 Emergency Power generator



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

GENERAL EQUIPMENT

ITEM NO.

QTY. DESCRIPTION

Z 995 A/B 2 Storm Sewer Collection SumpZ 996 1 OWS Collection SumpZ 1101 1 Vapour ScrubberZ 1103 1 SCO Steam DesuperheaterZ 1104 2 Carbon CanistersZ 1121 1 SCO Feed Air FilterZ 1122 1 SCO Reactor Feed FilterZ 1123 A/B/C 3 SCO Reactor Effluent FiltersZ 1124 1 SCO SLM Steam DesuperheaterZ 1125 1 SCO Reactor Sparger Capsules (1 Lot)Z 1126 1 SCO Feed Steam FilterZ 1127 1 SCO Vent Gas Silencer

FURNACES

ITEM NO.

QTY. DESCRIPTION

H 110 1 USC Fresh Feed FurnaceH 111 1 USC Recycle FurnaceH 120 1 USC Fresh Feed FurnaceH 121 1 USC Recycle FurnaceH 130 1 USC Fresh Feed FurnaceH 131 1 USC Recycle FurnaceH 140 1 USC Fresh Feed FurnaceH 150 1 USC Fresh Feed FurnaceH 160 1 USC Fresh Feed FurnaceH 170 1 USC Fresh Feed FurnaceH 180 1 USC Fresh Feed FurnaceH 190 1 USC Fresh Feed FurnaceH 192 1 USC Fresh Feed FurnaceH 194 1 USC Fresh Feed FurnaceH 196 1 USC Fresh Feed FurnaceH 710 1 1st Stage Reactor Treatment FurnaceH 740 1 2nd Stage Reactor Feed Heater / Regeneration Furnace



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

PUMPS

ITEM NO.

QTY. DESCRIPTION

P 210 A/C 3 Q.O. Circulating PumpP 211 A/B 2 Pan Oil Circulating PumpP 220 A/C 3 Quench Water Circulating PumpP 221 A/B 2 Quench Oil Tower Reflux PumpP 225 A/C 3 Secondary Quench Water Circ. PumpP 230 A/B 2 Heavy Fuel Oil Product PumpP 240 A/B 2 Light Fuel Oil Product PumpP 250 A/B 2 Distillate Stripper Bottoms PumpP 260 A/B 2 Dilution Steam Stripper Feed PumpP 270 1 QO Drain Drum PumpP 300 A/B 2 Wash Oil Injection PumpP 310 A/B 2 C.G. 1st Stage Condensate PumpP 320 A/B 2 Distillate Stripper Feed PumpP 341 A/B 2 Concentrated Caustic PumpP 342 A/B 2 Weak Caustic Circulating PumpP 343 A/B 2 Medium Caustic Circulating PumpP 344 A/B 2 Strong Caustic Circulating PumpP 345 A/B 2 Wash Water Circulating PumpP 346 A/B 2 Caustic Area Sum[p PumpP 347 A/B 2 Aromatic Gasoline Circulating PumpP 348 A/B 2 Spent Caustic Discharge PumpP 349 1 Aromatic Gasoline Injection PumpP 355 A/B 2 Cracked Gas Rectifier Reflux PumpP 360 A/B 2 Condensate Stripper Bottoms PumpP 400 A/B 2 Methanol PumpP 401 1 Methanol Unloading PumpP 425 A/B 2 Demethanizer Reflux PumpP 445 A/B 2 Deethanizer Reflux PumpP 451 A/C 3 C4 Coolant Circ. PumpP 470 A/B 2 Ethylene Rectifier Bottoms PumpP 475 A/B 2 Ethylene Rectifier Reflux PumpP 515 A/B 2 Depropanizer Reflux PumpP 516 A/B 2 C3 Hydrogenation Feed PumpP 520 A/B 2 C3 Hydrogenation Recycle PumpP 530 A/B 2 Secondary Deethanizer Bottoms PumpP 535 A/B 2 Secondary Deethanizer Reflux PumpP 536 A/B 2 Tertiary Deethanizer Bottoms PumpP 537 A/B 2 Tertiary Deethanizer Reflux PumpP 550 A/B 2 Propylene Transfer PumpP 555 A/B 2 Propylene Tower Reflux/Product PumpP 565 A/B 2 Debutanizer Reflux/Product PumpP 701 A/B 2 1st Stage Feed PumpP 710 A/B 2 1st Stage Quench Pump



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

PUMPS

ITEM NO.

QTY. DESCRIPTION

P 711 A/B 4 Polymerisation Inhibitor PumpP 725 A/b 2 Depent anizer Reflux PumpP 730 A/B 2 Deoctanizer Bottoms pumpP 731 A/B 2 Wash Oil Transfer PumpP 735 A/B 2 Deoctanizer Reflux PumpP 736 A/B 2 2nd Stage Feed PumpP 740 A/B 2 2nd stage Quench PumpP 742 1 DMDS Injection PumpP 750 A/B 2 C6-C8 Product PumpP 752 1 Corrosion Inhibitor PumpP 755 A/B 2 Stripper Reflux PumpP 801 A/B 2 Feed PumpP 802 A/B 2 Recycle PumpP 803 A/B 2 C4 Product PumpP 900 A/C 3 Boiler Feed Water PumpP 901 A/B 2 LP Boiler Feed Water PumpP 902 A/B 2 knock-out Drum Slops PumpP 910 A/C 3 Boiler Feedwater Make-up PumpP 914 1 CPU Feed PumpP 915 A/B 2 Polisher Caustic PumpP 916 A/B 2 Polisher Acid PumpP 917 1 Polisher Effluent PumpP 930 A/B 2 CG Compressor Turbine Condensate PumpP 931 A/B 2 Cracked Gas Compressor Seal Oil PumpP 932 A/B 2 Cracked Gas Compressor Lube Oil PumpP 942 A/B 2 Methane Expander / Rcomp. Condensate PumpP 956 A/B 2 Debutanizer Reboiler Condensate PumpP 960 A/B 2 C2R Comp. Turbine Condensate PumpP 961 A/B 2 C2/C3 Refrig Comp. Lube / Seal Oil PumpP 965 A/B 2 C3R Comp. Turbine Condensate PumpP 971 A/B 2 S/E LO Pump B-710 A/BP 974 A/B 2 S/E LO Pump B-740 A/BP 981 A/C 3 Phosphate Injection PumpP 982 A/B 2 Hydrazine Injection PumpP 983 A/C 3 Polymerisation Inhibitor Injection PumpP 985 A/D 4 Fresh Feed Furnaces DMDS Injection PumpsP 986 A/C 3 DMDS Injection PumpP 987 A/B 2 Corrosion Inhibitor Injection PumpP 988 A/B 2 Defoaming Agent Injection PumpP 989 A/B 2 Suspect Condensate PumpP 990 A/B 2 Fuel Gas Compressor Lube / Seal Oil PumpP 991 A/C 3 Boiler Feedwater Lube Oil Pump



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

PUMPS

ITEM NO.

QTY. DESCRIPTION

P 992 A/B 2 Aux. Corrosion Inhibitor Injection PumpsP 995 A/D 4 Storm Sewer Transfer PumpP 996 A/B 2 OWS Transfer PumpP 997 A/B 2 Portable Dewatering PumpP 1101 A/B 2 Spent Caustic Feed / Recycle PumpP 1102 A/B 2 High Pressure Feed PumpsP 1103 A/B 2 Effluent Transfer PumpsP 1104 A/B 2 Steam Stripper Bottoms PumpP 1121 A/B 2 SCO Reactor Feed PumpP 1122 A/B 2 SCO Effluent Transfer Pump



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

REACTORS

ITEM NO.

QTY. DESCRIPTION

R 451 A/C 3 C2 Hydrog. Adiabatic ReactorR 452 A/B 2 Prim. C2 Hydrog. Adiabatic ReactorR 531 A 1 C3 Hydrog. Reactor # 1R 531 B 1 C3 Hydrog. Reactor # 2R 531 C 1 C3 Hydrog. Reactor # 3R 532 1 C3 Hydrog. Second Stage ReactorR 710 A/B 2 First Stage ReactorR 740 1 Second Stage ReactorR 801 1 Hydrogenation ReactorR 802 1 Final Hydrogenation ReactorR 803 1 C4H Reactor (Unit-2)R 804 1 C4H Final Hydrog. Reactor (Unit-2)R 1101 1 Oxidation ReactorR 1122 A/B/C 3 SCO Reactor

TANKS

ITEM NO.

QTY. DESCRIPTION

T 300 1 Wash Oil TankT 340 1 Concentrated Caustic TankT 400 1 Methanol TankT 711 1 Polymerisation Inhibitor TankT 752 1 Corrosion Inhibitor TankT 900 1 CPU Feed Surge DrumT 910 1 BFW Make-up Storage TankT 914 1 Polisher Acid Storage TankT 915 1 Polisher Caustic TankT 916 1 Polisher Acid TankT 981 1 Phosphate Mixing TankT 982 1 Hydrazine Mixing TankT 983 1 Polymerisation Inhibitor TankT 986 1 DMDS TankT 987 1 Corrosion Inhibitor Mixing TankT 988 1 Defoaming Agent Mixing TankT 1101 A/B 1 Spent Caustic Holding Tank



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

DRUMS

ITEM NO.

QTY. DESCRIPTION

V 061 1 LPG/C4 raffinate Vaporiser Feed DrumV 110 1 Steam Drum (USC Furnace)V 111 1 Steam Drum (USC Recycle Furnace)V 120 1 Steam Drum (USC Furnace)V 121 1 Steam Drum (USC Recycle Furnace)V 130 1 Steam Drum (USC Furnace)V 131 1 Steam Drum (USC Recycle Furnace)V 140 1 Steam Drum (USC Recycle Furnace)V 150 1 Steam Drum (USC Recycle Furnace)V 160 1 Steam Drum (USC Recycle Furnace)V 170 1 Steam Drum (USC Recycle Furnace)V 180 1 Steam Drum (USC Recycle Furnace)V 190 1 Steam Drum (USC Recycle Furnace)V 192 1 Steam Drum (USC Recycle Furnace)V 194 1 Steam Drum (USC Recycle Furnace)V 196 1 Steam Drum (USC Recycle Furnace)V 198 1 Decoke Drum Separator/SilencerV 199 1 Decoke Drum Separator/SilencerV 262 A/B 2 Water Stripper Feed CoalescerV 270 1 Quench Oil Drain DrumV 310 1 CG First Stage Suction DrumV 320 1 CG Second Stage Suction DrumV 330 1 CG Third Stage Suction DrumV 335 1 CG Third Stage Discharge DrumV 340 1 CG Fourth Stage Suction DrumV 342 1 Spent Caustic Deoiling DrumV 343 1 Spent Caustic Degassing DrumV 346 1 Cracked Gas Rectifier Reflux DrumV 359 1 Condensate Stripper Feed CoalescerV 370 A/B 2 Cracked Gas DehydratorsV 371 1 Reactivation Gas SeparatorV 403 1 Demethanizer Preclr. No.3 Refrig. Flash PotV 406 1 Demethanizer Preclr. No.6 Flash PotV 410 1 Demethanizer Prestripper Feed DrumV 411 1 Demethanizer Feed Drum No.1V 412 1 Demethanizer Feed Drum No.2V 413 1 Demethanizer Feed Drum No.3V 414 1 Demethanizer Prestripper Parallel Feed DrumV 415 1 Demethanizer Parallel Feed Drum No.1V 416 1 Demethanizer Parallel Feed Drum No.2V 417 1 Demethanizer Parallel Feed Drum No.3



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

DRUMS

ITEM NO.

QTY. DESCRIPTION

V 418 1 Methane Expander 2nd Stage Suction DrumV 419 1 E-419 Knockout DrumV 420 1 Demethanizer Reboiler Refrig. Seal PotV 422 1 Demethanizer Parallel Precooler # 4 Flash Pot AV 423 1 Demethanizer Parallel Precooler # 4 Flash Pot BV 424 1 Demethanizer Parallel Precooler # 6 Flash Pot BV 425 1 Demethanizer Condenser Refrig Flash PotV 426 1 Demethanizer Reflux DrumV 431 1 Hydrogen DrumV 432 1 PSA Unit Surge DrumV 436 1 Residue Gas Rect. Reflux DrumV 445 1 Deethanizer Condenser Refrig. Flash potV 446 1 Deethanizer Reflux DrumV 453 A/B 2 Secondary DehydratorsV 455 1 C2 Hydrogenation Effluent SeparatorV 460 1 Ethylene Stripper Refrig. Seal PotV 476 1 Ethylene Rectifier Reflux DrumV 477 1 Ethylene Prod. Vaporiser Refrig. Seal PotV 480 1 Ethylene Product Cooler No.1 Refrig. Flash PotV 481 1 Ethylene Product Cooler No.2 Refrig. Flash PotV 482 1 Ethylene Product Cooler No.3 Refrig. Flash PotV 490 1 HP Ethylene Product Heater No.1 Seal PotV 516 1 Depropanizer Reflux DrumV 519 1 C3 Hydrogenation Feed CoalescerV 525 1 C3 Hydrogenation SeparatorV 536 1 Secondary Deethanizer Reflux DrumV 537 1 Tertiary Deethanizer Reflux DrumV 556 1 Propylene Rectifier Reflux DrumV 566 1 Debutanizer Reflux DrumV 610 1 Ethylene Refrig. 1st Stage Suction DrumV 620 1 Ethylene Refrig. 2nd Stage Suction DrumV 630 1 Ethylene Refrig. 3rd Stage Suction DrumV 645 1 Ethylene Refrigerant Surge drumV 646 1 Ethylene Refrigerant Drain DrumV 650 1 Ethylene Refrigerant Subcooler Flash potV 660 1 Propylene Refrig. 1st Stage Suction DrumV 670 1 Propylene Refirg. 2nd Stage Suction DrumV 680 1 Propylene Refrig. 3rd Stage Suction DrumV 690 1 Propylene Refrig. 4th Stage Suction DrumV 695 1 Propylene Refrigerant Surge DrumV 696 1 Propylene Refrigerant Drain DrumV 701 1 Feed Surge DrumV 710 1 1st Stage Hot Separator



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

DRUMS

ITEM NO.

QTY. DESCRIPTION

V 711 1 1st Stage Cold SeparatorV 712 1 1st Stage Knock-out DrumV 713 1 Decoking DrumV 726 1 Depentanizer Reflux DrumV 731 1 Wash Oil Holding DrumV 736 1 Deoctanizer Reflux DrumV 737 1 Z-736 Oily Water SeparatorV 740 1 2nd Stage Separator DrumV 741 1 2nd Stage Knock-out DrumV 756 1 Stripper Reflux DrumV 801 1 Feed Surge DrumV 802 1 Hot SeparatorV 803 1 Cold SeparatorV 804 1 C4 Product Flash DrumV 805 1 C4H Feed Surge Drum (Unit-2)V 606 1 C4H Hot Separator (Unit-2)V 807 1 C4H Cold Separator (Unit-2)V 808 1 C4 Product Flash Drum (Unit-2)V 900 1 DeaeratorV 901 1 Cold Flare Knock-out DrumV 902 1 Hot Flare Knock-out DrumV 904 1 S3.5 Suspect Condensate DrumV 905 1 AGO Feed Heater No.3 Condensate PotV 906 1 AGO Feed Heater No.2 Condensate PotV 907 1 Methanol Vaporiser No.1 Condensate PotV 908 1 Cold Blowdown Vaporiser Condnesate PotV 915 A-C 3 Polisher Mixed Bedsv 916 1 Polisher Regn VesselV 917 1 Polisher Effluent VesselV 920 1 S40 Steam Condensate Flash DrumV 926 1 DSG Feed Heater No.2 Condensate PotV 927 A/B 1 DSG Reboiler Condensate PotsV 928 1 Quench Water Steam Heater Condensate PotV 930 1 S12 Steam Condensate Flash DrumV 931 1 Continuous Blowdown DrumV 932 1 Intermittent Blowdown DrumV 937 1 Reactivation Gas Heater Condensate PotV 940 1 Fuel Gas Mixing DrumV 945 1 C2 Hydrog. Feed Water Condensate PotV 946 1 C2 Hydrog. Adia Reactor Feed Htr Cond. PotV 954 1 Propylene Tower Reboiler Condensate PotV 956 1 Debutanizer Reboiler Condensate PotV 961 1 LPG/C4 Raffinate Vaporiser Cond PotV 972 1 Depentanizer Reboiler Condensate Pot



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

Table 1

ITEM NO.

QTY. DESCRIPTION

V 973 1 Deoctoniser Reboiler Condensate PotV 975 1 Stripper Reboiler Condensate PotV 980 1 C3/C4 Fuel Vaporiser Condensate PotV 981 1 Fuel Gas Superheater Condensate PotV 1101 1 Steam Stripper Feed Preheater Condensate PotV 1102 1 Water K.O. DrumV 1103 1 SCO Reactor Feed Surge DrumV 1121 1 SCO Feed Surge DrumV 1122 1 SCO Effluent Surge DrumV 1123 1 SCO Air Surge Drum



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

FLARE SYSTEM



B. DAS AUTHOR BMK

SECTION MODULE NO.


CKR-PR-P-001

7.1 Pressure Relief, Blowdown and flare system

7.1.1 Pressure Relief Valve Header System

Within Cracker Plant, a relief valve Header system is provided

to collect hydrocarbon discharges :

1. The C2 & lighter effluents which below -450C are collected in

the cold flare header made of autenitic steel subjected to

gravity separation in the cold flare knockout drum and steam

superheated prior to being discharged to the hot flare header.

2. Cold dry effluents (basically C3) at temperatures from 0C to -

450C are collected in the intermediate flare header (IF) which is

(LTCS) subjected to gravity separation in the same knock-out

drum as the C2 and lights effluents.

3. Hot wet effluents above 0C are collected in a carbon steel

header and subjected to gravity separation in the horflare

knockout drum. The gases from this drum joined by the

superheated effluent from the cold knockout drum and sent to

OSBL flare stack.

4. Cold flare knock out drum vaporiser which vaporises any

liquid lighters and the outlet superheater is provided, heated by

steam via an intermediate methanol loop as a heating medium.

7.1.2 Blowdown SystemCHECKED BY PAGE 145



SECTION MODULE NO.


CKR-PR-P-001

Blowdown Systems are provided to remove residual

hydrocarbon only during unit shut down or fire emergency. The

drains of all hydrocarbons that will vaporise when opened to

atmosphere are routed to the blowdown system. Hot blowdown

is having CS piping (above 0C) and cold blown is provided with

SS headers. These drain are collected in a common headers

and terminate in their corresponding relief valve header KW

drums.

Provision is made for vaporising any coalesced liquids. In cold

flare knockout drum, a steam heated indirect exchanger is

used while in hot flare knock out drum a steam coil is used.

Any accumulated liquid from cold or hot flare knock out drum

are pumped either to quench oil tower or to OSBL.

7.2 Flare system at OSBL

Flare from cracker ISBL, Tank farm, MEG & Aromatics gaseous

effluents are collected in the common header and are routed to

OSBL flea stack system.

Flare stack system, corrosion of knock out drum where any

liquid is separated. Then gases are passed to liquid drum where

these gases bubbled through water seal and reach the flea

stack. Then there gases pass through molecular seal at the

stack top and are burnt at the flare tip.CHECKED BY PAGE 146



SECTION MODULE NO.


CKR-PR-P-001

4 No.s of burners continuously burn at the tip which is supplied

by fuel gas separately. Flare front generator located at grade

provides necessary ignition for putting pilots on these are

designed remain on even during heavy wind with rain. Each

pilot is provided with a thermocouple which sends any loss of

flare and connected to alarm. System both out the local panel

and in DCS. Also, one thermocouple provided at the centre of

the tip gives warning incase of any burnback.,

Two stages of steam are provided one at the centre into the

flare trip to cool the flea provides steam for complete

combustion. Centre, steam is adjusted manually at controlled

rate and the QS steam which is varied in accordance to the flow

to obtain smokeless flare.

Flare stack design parameters

Flare Gas:

Flow Rate : 1,050,689 kg/hr

Mot. Wt. : 33.26

Temp.: 800C

Pilot Gas:

Type : Fuel GasCHECKED BY PAGE 147



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Pressure : 1002 kg/cm2g

MW : 19.57

Steam :

Pressure : 7.03 kg/cm2g @ flare trip.

Flow max. : 32,659 kg/hr QS manifold @ 7.03 kg/cm2g

Flow : 430 kg/hr. Cooling rate for QS manifold

Flow Max. : 3855 kg/hr. through centre tip @ 7.03 kg/cm2g

Flow : 225 kg/cm2g cooling rate for center tip @ 7.03 kg/cm2

OPERATING INSTRUCITONS :

Pre-Start Up Check List

Before starting up the flare, checks should be made for the

following items :

1. Verify that all the flare components are installed in

accordance with the reference drawings.

2. If chromel-alumel Type K thermocouples are used, the blue

wire is negative (-) and the brown wire is positive (+).

3. All system lines should be dry and free of dirt and foreign

material.

4. Check that all drain and vent valves are closed and that all

drain and vent plugs are tightly secured. A drain plug or

valve is required at each low point in each pilot ignition line.

5. All manual valves in the pilot gas and waste gas systems

should be closed.

6. Check that all set points are properly adjusted.



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7. The pilot ignition lines must be dry and unobstructed so that

the flame front is not quenched or blocked.

Start-Up and Operation Procedures for Smokeless Flare

System (QS-C):

The EEF-QS-60/66C flare uses 4 Energy Efficient Pilots as an

ignition source. The flare is equipped with a 8” QS Steam

Manifold and steam injectors capable of providing 32,659 kg/hr

of saturated steam @ 7.03 kg/cm2g. A 3” Centre Steam

Sparger is included which is capable of providing 3,855 kg/hr of

saturated steam @ 7.03kg/cm2g.

A continuous steam flow of 375 kg/hr should be maintained to

the QS Steam Manifold for cooling and to prevent cracking of

the steam injectors and manifold. The centre steam sparger

requires 225 kg/hr of cooling steam.

1. Start up and operation:

Light the pilots:

The method of lighting the 4 pilots should be carried out using

the flame front generator panel. (refer to appendix “A” -

“Operating Instructions for Flame Front Generator” - Bulletin

5401E (2 pages).

c) Introduce the cooling steam flow to the Centre Steam (225

kg/h). The Centre Steam rate should be set manually.



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d) Introduce the cooling steam flow to the upper QS Steam

Ring (375 kg/hr).

e) Start the waste gas flow at a nominal vent rate (500-1000

kg/hr)

f) With the QS Steam set at the cooling rate of 375 kg/hr,

adjust the Centre Steam until smokeless operation is

achieved. It may be necessary to make this adjustment

several times with the flea receiving gas at the nominal vent

rate.

When the required Centre Steam rate is achieved, it should be

changed. It is suggested that the Centre Steam manual valve

handle be removed.

Since one of the purposes of the Centre Steam is to prevent

burn-back inside the flare tip, it is advisable to observe the flare

tip at night for a glow (excessive heat) below the flare tip exit.

The above procedure should be followed for initial start-up.

g) During a flaring event, the steam flow to the QS Steam

Manifold should be adjusted to the point where smoke is not

visible and the flame is a yellow orange colour. The amount

of steam to achieve this is anticipated to be 0.4 kg steam

per 1.00 kg. waste hydrocarbon.

h) After cessation of a flaring event, the QS Steam Manifold

rate should be returned to a rate of 375 kg/h for cooling. Do

not readjust the centre steam rate as the flare will still be

experiencing a nominal vent rate of waste gas.CHECKED BY PAGE 150



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2. Shut down

a) Close the steam supply valves to the QS Steam Manifold on

the flare trip. Close the steam supply to the Centre Steam

Sparger.

c) Shut Down the purge gas flow :

d) Extinguish the pilots by closing the pilot fuel gas block valve.

e) Close all hand valves.

f) Close all utility gas supply systems

OPERA TING INSTRUCITIONS FOR FLAME FRONT GENERATOR

Important :

A. All ignition lines must be one rich.

B. All low spots in ignition lines must be drained

Note : Sagging between supports is sufficient to cause low

spots in the line which can hold liquids and quench ignition

flame.

C. Confirm that all utilities are connected and operating

properly per the job drawing.

Ignition :

1. Purge flare system with nitrogen or fuel gas until all oxygen

has been replaced with purge gas.

Blow down air and gas supply lines to flame front generator at

blow down valves to remove condensate. Open all drains in the

low spots of ignition lines. Blow down each ignition line, one at



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a time, through valves A,E and C. Close all drains. Check each

ignition line for blockage by opening valve D and at a time.

When valve D is closed, pressure should fall off rapidly on the

pressure gauges. If pressure does not fall off rapidly,

investigate and correct the blockage in the ignition line.

3. Push switch ‘F” actuate Magiclite to check for spark at the

sight port.

4. Open valve “A’. Close valve “B” and “C” to ignite pilot No.1

5. Open valve “H”. This is the fuel for pilots.

6. Open valve “E” and set pressure gauge at 10 psig. (gas).

7. Open valve “D” and set pressure gauge at 13 psig. (air).

8. Wait two to three minutes after opening valves E and D.

9. Push and release quickly, switch “F”. At the same time

observe through the sight port to see if air/gas mixture was

ignited.

(If same is not observed, change either the air or gas slightly

until flame is observed). If the system uses Magiclite ignitor,

actuate as if you were using switch “F”.

10. If pilot does not light, repeat steps 8 and 9.

11. If repeating steps 8 and 9 two or three times does not ignite

the pilot, change air or gas pressure slightly using valve “D” or

valve “E”. Repeat steps 8 and 9 until pilot is ignited.

12. Close valve “A”. Open valve “B” to ignite Pilot No.3. Repeat

steps 8 and 9 until the pilot is ignited.

14. When all pilots are ignited, close valves ‘D” and “E”.



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15. On light or sunny days, if is difficult to observe pilot flame

to verify ignition. To observe pilot flame, close valve “D” and

open valve “E” fully for two or three minutes. If ignited, pilot

flame will become luminous. This can be repeated for each pilot

by opening and closing valves A,B, and C.

16. After all pilots are ignited and verified, the flea is ready for

operation. Waste gas can now be flared provided the remainder

of each system is operational.

1. If no spark is observed, check the electrical circuit and the

spark gap (1/16-1/8 inch).

If a blue flash cannot be observed at the sight glass, check for

gas and air delivery as follows :

A. Disconnect the spark plug lead and remove sight glass.

B. Check for air delivery by opening valve “D” and check for

gas delivery by opening valve “E”.

C. If a noticeable hiss does not occur, break the piping union

and check orifices at “I” (air). and “J” (gas).

3. If the pilot will not light and the above have been confirmed.

A. Check the piping between the flame front generator and the

pilot to ensue no low points in the piping have filled with

condensate.

B. Ensure that pilot gas pressures is per job drawing.

If a fuel gas other than that specified on the job drawing used,

the orifices “I” and “J” must be resized. Please contact John

Zink in Tulsa for specific recommendations.



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FIRE & GAS DETECTION SYSTEM



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1. INTRODUCTION

Industrial processes increasingly involve the use and manufacture of highly dangerous substances, particularly toxic and combustible gases. Inevitably, occasional escapes of gases occur creating a potential hazard to the industrial plant, its employees and people living nearby. In most industries, one of the key parts of any safety plan for reducing the risks to personnel and plant is the early-warning device such as Gas Detectors. These can help to provide more time in which to take remedial or protective action. They can also be used as part of total, integrated monitoring and safety system for an industrial plant.This report is intended to offer an overview of the Fire and Gas Detection System in Naphtha Cracker plant in RIL, Hazira. It provides a brief explanation of the principles involved in such systems and the instrumentation needed for satisfactory protection of personnel and environment.Some of the topics related to the Fire and Gas Detection system are also discussed.

2. COMBUSTIBLE GASES

Combustion is basically a simple chemical reaction, in which oxygen combines rapidly with another substance resulting in the release of energy. This energy appears mainly as heat - sometimes in the form of flames. The igniting substance is normally, but not always, an organic or hydrocarbon compounds and can be a solid, liquid, vapor or gas.

FIRE

AIR

FUEL

HEAT

The process of combustion can be represented by the well-known fire triangle. As can be seen, three factors are always needed i.e. a source of ignition, oxygen and fuel in the form of combustible gas or vapor. In any fire prevention system, therefore, the aim is always to remove at least one of these potentially hazardous items.

3. TOXIC GASES

Though there is a large group of gases, which are both combustible and toxic, the hazards and the regulations involved and the types of sensor required are different for the two categories of the gases. With toxic substances, (apart from the obvious environmental problems) the main concern is the effect on workers of exposure to even very low concentrations, which could be inhaled, ingested or absorbed through the skin. It is important not only to measure the concentration of gas, but also the total time of exposure, since adverse effects can often result from additive, long-term exposure.



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Sometimes these substances can interact and produce a far worse effect when together than the separate effect of each on its own.Concern about concentrations of toxic substances in the workplace focus on both organic and inorganic compounds, including the effects they could have on the health and safety of employees, the possible contamination of a manufactured end product (or equipment used in its manufacture) and also the subsequent disruption of normal working activities.Concentrations of gas in air are expressed as parts per million (ppm), which is a measure of gas concentration by its volume.

4. EXPLOSIVE LIMITS

There is only a limited band of gas/air concentration, which will produce a combustible mixture. This band is specific for each gas and vapor and bounder by an upper level, known as the Upper Explosive Limit (UEL) and a lower level, called the Lower Explosive Limit (LEL).

TOORICH

FLAMMABLE RANGE

TOOLEAN

100% air0% gas

LEL

UEL

100% gas0% air

At levels below the LEL, there is insufficient gas to produce an explosion (i.e. the mixture is too lean), whilst above the UEL, the mixture has insufficient oxygen (i.e. the mixture is too rich). The flammable range therefore falls between the limits of the LEL and UEL for each individual gas are mixture of gases. Outside these limits, the mixture is not capable of combustion.

5. HAZARD ZONES

Not all areas of an industrial plant or site are considered to be equally hazardous. For instance, an underground coal mine is considered at all times to be an area of maximum risk, because some methane gas can always be present. On the other hand, a factory where methane is occasionally kept on site in storage tanks, would only be considered potentially hazardous in the area surrounding the tanks or any connecting pipe work. In this case, it is only necessary to take precautions in those areas where leakage could reasonably be expected to occur.



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In order to bring some regulatory control into the industry, therefore, certain areas have been classified as follows :

ZONE 0 in which an explosive gas/air mixture is continuously present, or present for long periods.

ZONE 1 in which an explosive mixture is likely to occur in the normal operation of the plant.

ZONE 2 in which an explosive mixture is not likely to occur in normal operation.

6. GAS DETECTION SYSTEMS AND GDACS

For continuously monitoring an industrial plant for leakage of hazardous gases, a number of sensors are placed at strategic points around the plant at the places where any leaks are most likely to occur. These are then connected to a multi-channel controller located some distance away in a safe, gas free area having display and alarm facilities, recording devices, etc. This is known as Fixed point system. It is permanently located in the industrial plant (i.e. oil refinery, cold storage, etc.) and generally has a standard analogue electrical circuit design. The controllers used in the fixed systems are normally centrally located in a control panel. The control units normally have internal relays to control functions such as alarm, fault and shut down. The alarm can be set at either one or two levels, depending on statutory requirements or working practices within the industry. Alarm inhibit and reset, over-range indication and an analogue 4-20 mA output for a data logger or computer are some of the useful features of the control units.

GDACS stands for Gas Data Acquisition and Control System. This system uses transmitters to convert the 4-20 mA signal of standard gas sensors into digitally coded pulses. It also allows the information from a number of other sources, temperature or pressure sensors, fire detectors, etc. to be interfaced to a two-wire, digital highway. Highway is a simple digital communication channel. Each input to the highway is allocated a unique address code and when a sensor is ‘interrogated’ by the highway control card, it transmits status information back to the control room. The use of the microprocessor technology enables the compensation of external environmental influences for greater accuracy. By two-way communication with the sensors, the system can provide operational status and diagnostic information. The system can accept ‘status switches’ on the highway in addition to analogue devices. By using addressable output actuators, it is possible to operate local alarms or shut down procedures from the highway itself, instead of wiring all functions back to the controller.

The highway control cards give an output with detailed status information from the input devices and these can be passed via a serial port to a suitable host computer and visual display unit.

7. LOCATION OF SENSORS



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There are three methods of locating sensors: Point Detection, where sensors are located near the most likely sources of leakage, Perimeter Detection, where sensors completely surround the hazardous area (which could also be point detectors) and Open path detectors (uses IR beam for detection), in which the detectors can be connected covering a distance of several hundred meters.

Some of the factors to be kept in mind while deciding the location of a sensor are given below :

1. Any sensor which is to be used for detecting a gas with vapor density greater than 1 ( i.e. heavier than air), e.g. Butane, LPG and Xylem, etc. should be located near ground level.

2. Conversely, for any lighter-than-air gases, such as hydrogen, methane, ammonia, etc. The sensor is to be connected higher-up.

3. In the open, environmental conditions get more importance. Sensors are to be located downstream of the prevailing winds and the weather shields are to be fitted to protect against rain and snow. Diffusion-type sensors will normally be mounted so that they face downwards, particularly for light gases.

4. The location of IR sensors should be such that, there is no permanent blockade of the IR beam. Though normally sunlight does not cause any problem, it should not fall directly on the instrument window.

5. The locations mostly requiring protection are around gas boilers, compressors, pressurized storage tanks, cylinders or pipelines. Valves, gauges, flanges, T-joints, filling or draining connections, etc. are most vulnerable. Sensors should be positioned a little way back from any high-pressure parts to allow gas clouds to form. Otherwise any leakage of gas is likely to pass by in a high-speed jet and not be detected by the sensor.

8. GENERAL OVERVIEW OF THE F&G SYSTEM IN NAPHTHA CRACKER PLANT

The Fire & Gas Detection System in the Cracker plant in RIL, Hazira has been supplied by Zellweger Analytics (Sieger) Ltd, UK. The system consists of two independent detection systems: Gas detection system and Fire detection system. The Gas Data Acquisition and Control System (GDACS) within the control cabinet provides four RS485 internal highways for gas, fire and fault condition data collection. It is an Analogue Addressable System.

The different types of gas and fire detectors used in this plant are as follows:

Gas detectors : 1. Combustible (hydrocarbon) 0-100% LEL detectors,2. Toxic gas detectors : a) Hydrogen Sulphide detectors 0-50

ppmb) Carbon Monoxide detectors 0-500

ppm

Fire detectors : 1. Smoke detectors : a) Opticalb) Ionization



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2. Heat detectors3. IR Flame detectors4. Manual Alarm Callpoints.

The system comprises five dual bay cabinets namely :

1. Gas control cabinet2. Fire control cabinet3. Marshalling cabinet4. Control room mimic cabinet5. Fire station mimic cabinet.

Both the Gas and Fire detection systems have two highways each. Highways one & two are used for gas detection system and Highways three & four are used for fire detection system. Individual gas sensor and fire loop status from the GDACS is given to a Data Concentrator. This data from the Data Concentrator goes to the DCS ( Distributed Control System) via a Protocol Converter.

Gas and fire alarms on a fire area-grouping basis are annunciated via control room and fire station mimic panels and by siren/visual/internal audibles directly within the fire areas. All field detector loops are terminated within the marshalling cabinet, which houses the intrinsic safety (I.S.) MTL isolation units for these circuits. Gas detection transmitter 24V DC feeds are also terminated in this cabinet, each circuit having fuse/isolation terminals.



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FIG : FIRE & GAS DETECTION SYSTEM BLOCK DIAGRAM

9. DETECTORS

9.1 Gas Detectors :



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The gas detectors comprise two main units - a transmitter and a sensor. All units use a weather protection assembly providing protection to the sensor-input sinter against rainwater splash and high air speeds.

9.1.1 Combustible Gas Detectors :

Nearly all modern, low cost, combustible gas detection sensors are of the electro-catalytic type. They consist of a very small sensing element called a ‘bead’, a ‘Pellistor’ or a ‘Siegistor’. They are made of an electrically heated platinum wire coil. The coil is covered first with a ceramic base such as alumina and then with a final outer coating of palladium or rhodium catalyst dispersed in a substrate of thoria as shown in the figure below. When a combustible gas/air mixture passes over the hot catalyst surface, combustion occurs and the heat evolved increases the temperature of the ‘bead’. This in turn alters the resistance of the platinum coil and can be measured by using the coil as a temperature thermometer in a standard electrical bridge (Whetstones Bridge) circuit. The resistance change is then directly related to the gas concentration in the surrounding atmosphere and can be displayed on a meter or some similar indicating device. The change in resistance gets converted to a 4-20 mA signal (by amplifier) which corresponds to 0-100%



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LEL.

FIG : A COMBUSTIBLE SENSOR



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FIG : DIMENSIONS OF A COMBUSTIBLE GAS DETECTOR

9.1.2 Toxic Gas Detectors :

Toxic gases are generally needed to be detected and measured at very low concentrations. Therefore, although many toxic gases are also combustibles (e.g. ammonia, carbon monoxide or methanol), it is not possible to use combustible gas sensors for toxic gas measurements because the sensitivity needed is well below that which can be achieved with a flammable gas sensor.A toxic gas detector uses an electro-chemical sensor. It is an electrochemical cell, consisting of two electrodes immersed in a common electrolyte medium. This can be in the form of either a liquid, a gel-like fluid, or an impregnated, porous solid. The electrolyte is isolated from outside influences by means of a barrier, which may be in the form of either a gas permeable membrane, a diffusion medium, or a capillary. The cell is designed for maximum sensitivity combined with maximum interference from any other gases present.

During operation, a polarizing voltage is applied between the electrodes and when gas permeates through the barrier into the sensor, an oxidation-reduction reaction generates an electrical current that is linearly proportional to the gas concentration.



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FIG : A TOXIC SENSOR

FIG : DIMENSIONS OF A TOXIC GAS DETECTOR

The Combustible and toxic gas detectors are identical in appearance accept that, the transmitter of a toxic gas detector is slightly smaller than that of a combustible gas detector as shown in the figures above.



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Total 180 combustible gas detectors are in the plant. Since the combustible gases have a tendency to go up, these detectors are placed mostly at the top. Each of 6 H2S & CO detectors are used in the top and ground floors of the HVAC Inlet area.

FIG : CONNECTION DIAGRAM OF A GD TO GAS CONTROL CABINET

9.2 Smoke Detectors :

Optical and Ionization Smoke Detectors are the two most common types of plug-in smoke detectors. Ionization detectors are excellent for detecting the smaller aerosols associated with clean fires, which result from fibrous materials, i.e. paper or wood. Therefore this detector is a good selection for office areas. The Optical detectors provide a better response for mid-range range to heavy or large aerosols such as those produced by many synthetic products. Therefore this detector is a better selection for protecting areas where this type of material is prominent, i.e. electrical switch rooms, cable spreader room, rack room, where overheated cables and electrical components are the main risk.Large smoke particles can also result from smaller aerosols combining together, which usually happens as smoke travels over longer distances, i.e. along corridors. That is why, in the control room building area, both the types of detectors have been connected side by side.



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FIG : SENSITIVITY OF THE DETECTORS TOWARDS SMOKE PARTICLES OF DIFFERENT SIZES

9.2.1 Optical Smoke Detector :

The inner chamber of an optical smoke detector consists of two main parts : an infrared LED and a photo-diode. The LED is positioned at an obtuse angle to the photo diode. The photo-diode has an integral daylight filter for protection against ambient light. The LED emits a burst of collimated light every 10 second. In clear air conditions the photo-diode does not receive light particles (photons) due to the collimation of the light and the angle at which the light travels relative to the photo diode. When smoke enters the chamber, it excites the photo-diode by scattering photons onto it. Then the LED emits two further bursts of light at an interval of two seconds. Due to the presence of smoke, light is scattered on both these pulses of the photo-diode causing the detector to go to the alarm state. At the alarm state, a silicon controlled rectifier on the printed circuit board is switched on and the current drawn by the detector is increased from an average of 40 mA to a maximum of 61mA. To ensure reliability, the LED emits light modulated at about 3 KHz and the photo-diode reacts only on receiving light at this frequency.

9.2.2 Ionization Smoke Detectors :



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An Ionization Smoke detector has an inner and an outer chamber. The inner & outer chambers are called ionization (inner reference chamber) and smoke chambers respectively. (The smoke chamber has smoke inlet apparatus fitted with an insect resistant mesh.) A radioactive source holder and the smoke chamber acts as positive and negative electrodes respectively. The radioactive source is inside the ionization chamber. This radioactive source irradiates the air in both the chambers to produce positive and negative ions. On applying a voltage across the electrodes, an electric field is formed. The ions are attracted to the electrodes of opposite signs, some ions collide and recombine, but a small net electric current flows between the electrodes. A sensing electrode between the two chambers converts variations in the chamber currents into a voltage. When smoke particles enter the ionization chamber, ions become attached to them and reduce the current flowing through the ionization chamber. The current in the smoke chamber reduces far more than that of ionization. This imbalance causes the sensing electrode to go more positive. The sensor electronics monitors the voltage on the sensing electrode and produces a signal when a preset threshold level is reached and causes the detector to go to the alarm state. The total number of smoke detectors used in this plant is 155 and these have been supplied by Apollo Fire Detectors Limited. The detectors are used inside the control room building area. These are mounted on the ceiling, above ceiling and below false flooring. Remote indicators are also provided for giving indication of any actuation above ceiling.

The Ionization & Optical Smoke detectors are identical in appearance. The difference is that, the color of the LEDs on the Ionization and Optical Smoke detectors are red and white respectively. But when they get actuated, both emit red light.

The total number of smoke detectors used in the control room building area is 155.

9.3 Heat detectors :

Heat detectors are basically temperature-sensing devices. The main function of the heat detectors is to provide fire detection where speed of response is not so critical, or for the areas where unwanted triggering of smoke detectors is likely to occur, i.e. kitchen and workshop areas.

Heat detectors are available in three basic forms --- Fixed Temperature, Rate of Rise sensors and Rate Compensated sensors. Fixed Temperature type detectors are used in this plant. These heat detectors may be of bi-metal switch design or of single fixed electronic thermal sensor design. These are designed with a pre-set fixed temperature trip point e.g. 60, 75 or 900C. If the preset temperature value is exceeded, contacts of the switch changes and generates alarm signal. The detector contact closes at operating temperature. The contact is self-resetting.The detector temperature setting is the sum of ambient temperature and 100 0F. Here, ambient temperature has been taken as 400F. Therefore the set point of the heat detectors is 1400F or 600C. The detector will give a low-level alarm if the temperature increases to 25% of its preset value.

In cracker plant only 13 Heat detectors are in use. Most of them are used in the transformer yard and Diesel Generator room.

9.4 IR Flame Detectors :



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The IR Flame Detectors provide early warning of hydrocarbon flames. The detectors are used for the protection of high risk areas from fire (producing CO2 ) caused by the accidental burning of materials, like flammable liquids & gases, paper, wood, plastics, etc. The detector uses infrared sensors, filters and microprocessor that provide immunity to ‘black body’ false alarm sources. The detectors have a very fast speed of response -- typically 2 to 3 seconds.

Two signals (waveforms) are derived from the 4.3 µm wavelength, which corresponds to hot CO2

emissions of a hydrocarbon fire. The microprocessor analyses this signal and another one taken from the 3.8µm wavelength by means of a parented correlation technique to determine the presence of fire. The detectors can see hydrocarbon flames through smoke and high densities of solvent vapors. These are blind towards sunrays.

There are 16 IR Flame Detectors in the plant. These have been supplied by Thorn Security Limited. The detectors are used mostly in the Crack Gas Compressor (CGC) Building, Refrigeration Compressor, Methane Compressor Shelter, Recycle Compressor and Fuel Gas Compressor area.

9.5 Manual Call Points :

The MAC is the simplest of all the other detectors used in the Fire and Gas detection System. This is a manually operated device. The MAC used in this plant is of ‘Break-glass’ type. The unit is operated by applying thumb pressure to a pre-scored glass plate, releasing a micro-switch, which is normally held open, by the edge of the glass plate and alarm is generated. The glass is covered by a clear film to protect the operator from suffering glass cuts or splinters during operation. During operation, the LED in the front side also glows.

The number of MACs used in the whole plant is 90.



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FIG : CONNECTION DIAGRAM OF MAC & SD FROM FIELD TO GAS PANEL

There are two level alarms for gas detection system : For 0-100% LEL detectors, Ist (lower) level alarm is at 20% LEL and 2nd (higher) level alarm is

at 60% LEL For 0-500 ppm CO detectors, Ist level alarm is at 10% i.e. 50 ppm and 2nd level alarm is at 60%

i.e. 300 ppm. For 0-50 ppm H2S detectors, Ist level alarm is at 20% i.e. 10 ppm and 2nd level alarm is at 50%

i.e. 25 ppm.

10. AUDIBLE AND VISUAL ALARMS

For warning the persons working in the plant of gas leakage or fire, Electronic Sounders are used. The tone of the sounder is very piercing (500 - 1000 Hz). The sound generated can be modulated in a number of ways (pulse, warble, multi tone, etc.) which makes the sound stand out from other ambient noises. In areas where the ambient noise is particularly high to the point where the occupants are required to use ear defenders, ‘flashing light’ alarm devices are also used as a visual backup warning to the occupants.

11. SYSTEM DESCRIPTION

11.1 Gas Control Cabinet :

The signals from all the gas detectors come to this cabinet via the Marshalling cabinet and are terminated in the four channel Safe Area Quad Input (SAQI) cards. These signals act as the input to the Highway Control Cards (HCC). The Gas Control Cabinet has four pairs of HCCs, functioning in a main and standby configuration. There are two Highways in each HCC : Primary and Secondary. The Primary Highway is normally active. The Secondary Highway is automatically used if failure of the Primary Highway is detected by the HCC. Communication takes place in one Highway at a time. Each pair of HCC’s has both a dual power supply card and a highway bus



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manager module. The bus manager module controls the switching from the main to standby HCC whenever the dual power supply card fails.

Dual Highway Voting Cards (HVC) are interfaced to each of the four highways to provide voted alarms. HVC takes signals from the HCC and votes as per user logic, which is configured in HVC and generates output. These outputs are used to indicate alarms, sirens, etc. The voting of the Fire Area is explained with the help of the voting logic and the cause and effect diagrams in the next page.

FIG : VOTING LOGIC FOR THE DETECTORS IN THE FA-3

FA - 3 VOTING MAIN CONTROL PANEL GRAPHIC MIMIC PANELS

D G ROOM AUD. ALMS VISUAL ALMS

CAUSE EFFECTS 2 OUT OF 2

2 OUT OF 3

AUDIBLE ALM

VISUAL ALARM

FIRE GAS AUD ALM(FS ONLY)

FIRE & GAS FIRE/FLAME GAS

DETECTION CCT

HEAT (POINT) 1ST X X X X X X

HEAT (POINT) 2ND X X X X X X X

GAS-FLAM 20% X X X

GAS-FLAM 60% 1ST X X X X

GAS-FLAM 60% 2ND X X X X X X X

MANUAL X X X X X X

FIG : CAUSE & EFFECT DIAGRAM FOR THE FA-3



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Highways one and two have twenty-eight SAQI cards each. Total sixteen no of 16 channel input cards are used in highways three and four. A SAQI card has four channels whilst a 16 channel I/P card has sixteen channels as the name suggests. The whole plant has been divided into different fire areas. All the gas, heat and IR flame detectors have unique addresses and they are connected individually to the highways. In some cases, MAC and smoke detectors of some fire areas have been connected in loops and these loops have been assigned unique addresses. The system being an Analogue Addressable System cannot check the status of each of the detectors in the loop. The incoming data of gas concentration and fault information is gathered on highways one and two and fire alarm/fault switch inputs are gathered on highways three and four. The 4-20 mA analogue loop signals from the gas detectors come to the SAQI cards, which convert them to digital format. The outputs of the SAQI cards are the inputs to highway one and two. The signals from smoke, heat, IR flame detectors and MAC come to 16 channel I/P cards (via 2 channel and 6 channel Fire cards). The output of these cards is given to highways three and four.

The main function of HCC in polling mode is to request data from each address loop. The data collected is checked against the configuration data in the EPROM in the HCC. The configuration data contains alarm settings and relay driver channel allocations for each Highway device address. If any alarm level, fault or warning code is present in the received message from an addressed device, a transistor relay driver channel may be activated. In some specific areas, some but not all detectors are voted for final output, e.g. Two out of three detectors are voted i.e. if any two detectors out of the three get actuated then only an output will be generated.

The Highways of all the four HCCs are connected to a Data Concentrator which acts as a multiplexer. The Data Concentrator can time division multiplex upto 8 HCCs. The Data Concentrator converts the RS 422 data from the HCC to RS 232 and gives it to the Protocol Converter. The Protocol Converter (based on Intel 80186 compatible single board computer) internally builds a table of GDACS gas readings, sensor statuses, types and ranges. It then communicates these values in a suitable format via a second serial port to the DCS system. The Protocol Converter converts GDACS protocol to MODBUS protocol, which is acceptable for ABB DCS.

11.2 Fire control cabinet :

The signals from the detectors used for fire detection come to this cabinet via the Marshalling cabinet and are terminated in the 16 channel I/P cards. The signals then go to the HCCs in the Gas control cabinet.Two types of cards are used for fire detection control. Twin Zone Fire card monitors the smoke detection loops and Six Channel Switch Input cards monitors the MAC loops.

Below the Fire Cards, there is a sub panel for providing annunciation and operation functions. These are as follows :

System healthy (Green LED)System faults (Amber LEDs)



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HVAC/Plant Status (Amber LEDs)Alarm resetAcceptLamp TestAudible alarm

The System Healthy indicator in the panel goes off whenever there is any fault in the system. The Twin Zone Fire Module monitors the detector loop current for open and short circuits and also passes a nominal quiescent current of 4 mA through the loop for monitoring.Any HARDWARE error condition is annunciated by visual and audible alarms within the control room for initial attention seeking. The audible alarm has two tones, continuous to define fire or gas alarm and intermittent to define a fault condition.

11.3 Marshalling cabinet :

The dual bay marshalling cabinet provides the main termination facility between field and control electronics.The panel contains all intrinsic safety isolating modules for input and output loops.

Type/model and loop type:

MTL 3041 Gas Detection 4/20 mA loops MTL 3043 Fire Detection 1/40 mA loops

Connections into the other system panels are being terminated in ELCO sockets.

11.4 Control room mimic cabinet :

The control room mimic panel is considered the master mimic. It houses LED display, graphically representing fire and gas zonal alarm status.

LED colors: Red (fire detection)Amber (combustible gas detection)Blue (Toxic gas detection)

Master/function/indications: Supply onSystem Alert (HVAC status change)System fault Lamp test (switch)

At the normal condition, all the LEDs and the lamps on the mimic panel are off. The ‘System Alert’ and ‘System Fault’ glow only when there is any fault in the system. The ‘Lamp Test’ switch is used for checking the working condition of the LEDs on the panel. The LEDs on a Fire Area glow when any gas leakage or fire is detected in that particular area. A draft of the cabinet is given on the next page.



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11.5 Fire station mimic cabinet :

The fire station mimic cabinet is similar to the control room in respect to the display.

12. SIEGER CALIBRATION & COMMUNICATION SOFTWARE PACKAGE, CALCOM

The operation of the G.D.A.C.S. is fully monitored and controlled with the help of software, which is known as CALCOM. A PC having CALCOM can be connected to the RS 232C serial interface on a Bidicom. The Bidicom is a bi-directional communicator, which can convert both RS 422 & RS 485 into RS 232 communications suitable for connection into a serial port of a computer.Whenever there is no visual indication defining any hardware failure, a software diagnosis can be done through CALCOM. The operator can interrogate a highway and its respective device address electronics asking for responses to the control commands. The responses contain more detailed data on occurrence of a fault. CALCOM is also used for calibrating the gas detectors.

13. CALIBRATION PROCEDURE OF GAS DETECTORS

Small particles, corrosion, water may block the sinter of a combustible sensor thereby causing its failure. Exposure to certain ‘poisons’ can also degrade the performance of a sensor. Therefore it is essential that any gas monitoring system should be calibrated at the time of installation as well as checked regularly and re-calibrated as necessary. An accurately calibrated standard gas mixture should be used for checking, so that the ‘zero’ and ‘span’ levels can be set correctly on the transmitter. Here we are using 2.5% methane in air as the calibration gas.To calibrate, one has to expose the sensor to a flow of gas and the other to check the reading shown on the scale of its control unit (PC). Adjustments are then made to the ‘zero’ and ‘span’ potentiometers until the reading exactly matches that of the gas mixture concentration. The calibration procedure for both the combustible and toxic gas detectors is same. Calibration can be done in situ or remote from the transmitter. Sensors can be pre-calibrated and then plugged in. The transmitter is factory set and does not require calibration. If required, the transmitter can be calibrated using a Dummy Sensor.

The sensors are calibrated remote from the transmitter using the Calibration unit as follows :

1. Power is applied and waited for 5 minutes for stabilization. 2. The calibration cover above the adjustment potentiometers are loosen and slided

up. The display on the calibration unit will show ‘CAL’.3. Zero potentiometer (MZ) is adjusted to obtain zero reading on the display.4. Test gas at the rate of 1-2 liters/min is applied and waited for 5 minutes to

stabilize.5. Span potentiometer is adjusted until display indicates 50% LEL of the test gas.6. Test gas is removed and zero is re-checked.



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7. The calibration cover is tightened (should not be over tightened). The display should read zero and the ‘CAL’ from the display should disappear.

The above procedure is repeated if necessary.

The dummy sensor is used to inject either a Zero or a variable signal into the transmitter. The procedure is as follows :

1. The sensor is removed from the transmitter to be calibrated and the dummy sensor is fitted in its place.

2. The transmitter local display should show ‘Fault’ and no gas reading.3. The transmitter should show zero reading when the switch on the dummy is in zero

position. If not, it should be made zero by adjusting the signal level knob until zero is displayed. Zero calibration command is given from the CALCOM (through the PC) connected to the Data Concentrator of the system.

4. The switch of the dummy sensor is changed to the Span position. Then the signal level knob is turned to inject a simulated ‘gas signal’ into the transmitter. The display on the transmitter should show 50% LEL. 50% Span calibration command from CALCOM is given.

5. The transmitter should indicate zero when the switch on the dummy sensor is kept in zero position. The transmitter should also indicate the correct value when the switch is kept on the span position.

6. After completing the tests, the dummy sensor is removed and the correct sensor is refitted to the transmitter.

The procedure is repeated if required.

14. CHECKING PROCEDURE

14.1 Smoke Detectors :

Smoke or spray is applied to the detectors to check their actuation.

14.2 Heat Detectors :

Heat is applied to the detector with the help of Heat Blower to see the actuation.

14.3 IR Flame Detectors :

Spark or fire flame is generated in front of the detectors and checked their actuation.

14.4 MAC :



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A special key to check its operation operates MAC. The LED in the front side does not glow when the MAC is in fault condition.

All the checking procedures given above are done online.

15. GRAPHICS PACKAGE

A Graphics computer having the Intellution FIX graphics software has been installed in the control room for quick and exact detection of the location of any fire or gas leakage. By the graphics interface, an operator gets an optimum presentation of site information. He can also view sensor and alarm data at any level of the hierarchical data structure.

An Overview screen provides the occurrence of alarm in any zone. It is indicated by the change of border color of that particular zone. The Menu bar at the bottom right corner in the overview screen has different function keys, e.g. Alarm, History, Engineer, etc. When Alarm screen is opened, a screen Menu appears at the right hand side of the Alarm Screen with options: Alarm Log Files & Log Files. The Alarm Log File enables the user to view the alarm log files listed in the date order. Log file option can be used to see the log on/off events and security violations. Alarm History gives the list of all the alarms in the buffer. The Engineering screen lists all the tags, their descriptions, current values, current status, and GDACS addresses for all the sensors in each zone. Normalization and Calibration of the gas sensors can be carried out from the Engineering screen Menu.

The Fire area select Menu on the top right corner of the Overview screen enables the user to view any particular fire area. A red surrounding of a fire area button indicates the occurrence of an alarm. The detectors on the screen as well as the alarm message appearing in the Alarm Summary field at the bottom of the screen changes their color corresponding to the type of alarm, e.g. a gas detector, which has been shown as Green at normal state, will become Orange to indicate a High alarm, Red to indicate HiHi alarm and Yellow to indicate a fault. This helps the operator to check whether actual fire or gas leak has taken place or not. Two buttons -- ‘Accept’ and ‘Alarm Reset’ are used for accepting and resetting an alarm.

A System screen can be viewed with the help of the ‘System’ button at the right side of the Overview screen.



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By double clicking at a sensor the user can view the Trend Graphs. The trend logs record 30 days

of data at 1-minute intervals. The trend graphs of the gas detectors can be useful for relating or

comparing the gas levels of the plant area at different times.



B. DAS AUTHOR BMK

Naptha Cracking Plant Operation

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