final internship report

INTERNSHIP REPORT 20

13

Umesh Kumar

ladhani

BYCO Petroleum Pakistan limitedORC-2

Interbship report of internship session aug-sep 2013 at ORC-2, from Umesh kumar ladhani(D-10-Ch-1249), student of Dawood university of engineering and technology Karachi, under supervision of Mr. abdul qadir dal.

Contents ACKNOWLEDGMENT

1. INTRODUCTION TO BYCO Oil Pakistan Ltd

2. EHS DEPARTMENT 3. Process Description

I. CRUDE UNIT PROCESS

a) Desalting

b) PRE-Heat Train

c) Furnace

d) Fractionating column

II. NAPHTA HYDRO TREATING UNIT

d) REACTIONS INVOLVED IN HYDROTREATING UNIT

III. GAS UNIT

IV. ISOMERISATION UNIT

4. UTILITIES

a) REVERSE OSMOSIS PLANT

b) COOLING TOWER

C) BOILER

d) DE ARATOR

ACKNOWLEDGEMENTAs an internee in BYCO Petroleum is undoubtedly the most learning and fascinating experience of my life. During my short 4 weeks internship in ORC-2, I got lots of learning, immense experience and useful social terms. I will remember BYCO always not just as a refinery but also as a complete institute with practical, theoretical and with experienced knowledge.

Through this report I would like to thank all the members of BYCO family, from top leadership to single employee, they all played a vital role during my internship tenure.

I specially pay my compliments to the following officials

Mr. Faraz Ahmed Sheikh (head of operations)Mr. Sakhawat AliMr. Sidique AhmedMr. Shoaib AhmedMr. Abdul Qadir DalMr. Farukh iqbalMr. AsadullahMr. ShamsMr. OwaisMr. NomanMR. Khalil ur rehman

I’m also grateful to all those operators who helped me during my task.Once again thank you BYCO petroleum Pakistan limited.

Umesh Kumar Ladhani.D-10-Ch-1249

INTRODUCTIONByco is Pakistan’s emerging energy companies engaged in the businesses of oil refining, petroleum marketing, chemicals manufacturing and petroleum logistics. Headquartered in Karachi. They are serving a mission to fulfill the energy demand within and beyond borders.Companies under BYCO umbrella are:

Byco Oil Pakistan Limited (BOPL) Oil Refining & Chemical Manufacturing

Byco Petroleum Pakistan Limited (BPPL) Oil Refining & Petroleum Marketing

Byco Terminals Pakistan Limited (BTPL) Petroleum Infrastructure & Logistics BYCO is engaged in manufacturing of a wide range of petroleum products with the objective to achieve sustainable productivity, profitability and high standards to address the environment, health and safety requirements.Byco's ORC-2 has a capacity to refine 1,20,000 barrels a day of crude oil into various saleable components including Liquefied Petroleum Gas, Light Naphtha, Heavy Naphtha, High Octane Blending Component, Motor Gasoline, Kerosene, Jet Fuels, High Speed Diesel and Furnace Oil.

Environment, Health and Safety (EHS)

At Byco petroleum Pakistan limited EHS is run under an integrated management system( IMS) . The basic goal is to develop the company on ethical and professional basis and be a responsible corporate entity with respect to Environment, health and safety. As for as the environment is

concerned , PAK-EPA (Pakistan environmental protection agency) keeps a check and balance on the environmental regulations. The company ensures

for the protection, conservation, rehabilitation and improvement of

environment , for the prevention and control of pollution, and promotion of sustainable development.

STANDARDS

Standards followed at BPPL are:

• Environmental management system(EMS) ISO 14,001

• Quality management system(QMS) ISO 9001

• Occupational health safety assessment series (OHSAS) ISO 18,001

PPE’s (Personal Protective Equipment):

Safety features are followed by every worker at the BPPL. All the workers wear PPE’s for their safety. This includes:

Safety helmet

Safety shoes

Safety cover Gloves, Air Filters, Goggles at sensitive areas

Body Safety Harness at height

PLANT SAFETY

Safety is the start of being safe /protected against failure, damage, error, accidents, harm or any other event. To prevent accidents main causes of accidents should be known.

TYPES OF HAZARDS

1. Fire and explosion hazards

2. Health and hygiene hazards

3. Electrical hazards

4. Pressure hazards

5. Maintenance

SAFETY EQUIPMENTS

1. Fire alarms

2. Smoke detectors

3. Personal protective equipment

4. Pressure control valves

5. Temperature control valves

6. Level control valves

7. Emergency shutdown valves

WORK PERMITS

Hot work permit: includes the work in which sparks are produced

Cold work permit: activates involve working in plant areas

Excavation work permit: including civil work

Confined space entry certificate: e.g. work inside confined space

Distillation ProcessCrude Distillation Unit (CDU):-THE CRUDE UNIT PROCESS PRINCIPLES:-

The Crude Unit can be divided into five sections:

1. Desalting Unit

2. Heat Exchangers

3. Furnaces

4. Crude Distillation Tower

5. Kerosene, LGO and HGO Stripper

The crude distillation unit is the first processing stage in the refinery. Here the crude is separated into five basic streams which are then further processed in the remainder of the refinery to yield a range of products from LPG to heavy fuel oil. Separation of the crude is accomplished by vaporizing and cooling the crude under controlled conditions so that fractions or cuts of the desired boiling range are obtained. In BYCO these are:

Stream Boiling range 0 F Description

Overheads 0 -320 overhead Naphtha

No.1 side stream 320-510 kerosene

No.2 side stream 510-680 light gas oil

No.3 side stream 680-750 gas oil

Bottoms 750+ reduced crude

FEED:-

The feed to the unit normally consists of predominately Qatar Marine crude. The unit is designed to handle 115 MBPD. The feed is pumped to the unit from crude storage by pumps located near the crude tanks.

DESALTING:-

Crude oil often contains water, inorganic salts, suspended solids, and water-soluble trace metals. As a first step in the refining process, to reduce corrosion, plugging, and fouling of equipment and to prevent poisoning the catalysts in processing units, these contaminants must be removed by desalting (dehydration).

The two most typical methods of crude-oil desalting, chemical and electrostatic separation use hot water as the extraction agent. In chemical desalting, water and chemical surfactant (demulsifies) are added to the crude, heated so that salts and other impurities dissolve into the water or attach to the water, and then held in a tank where they settle out. Electrical desalting is the application of high-voltage electrostatic charges to concentrate suspended water globules in the bottom of the settling tank. Surfactants are added only when the crude has a large amount of suspended solids. Both methods of desalting are continuous. A third and less-common process involves filtering heated crude using diatomaceous earth.

PRE-HEAT TRAIN:-

The heat exchangers used in byco is Shell and tube heat exchangers consist of a series of tubes. One set of these tubes contains the fluid that must be either heated or cooled. The second fluid runs over the tubes that are being heated or cooled so that it can either provide the heat or absorb the heat

required. Shell and Tube heat exchangers are typically used for high pressure applications.A crude oil processing system, comprising:

a plurality of heat exchangers defining a pre-heat train arranged along a crude oil flow path having an upstream end and a downstream end for progressively heating a flow of crude oil;

and a furnace for heating the crude oil for processing, wherein the furnace is disposed at the downstream end of the crude oil flow path at the end of the pre-heat train.

FURNACE:-

Furnace is a device used for heating. There are two types of furnaces,

Vertical furnace (tower furnace) Horizontal furnace (box furnace)

In ORC-2 at CDU plant-1 horizontal furnace is in use, in which there are 24 burners, 22 on fuel gas, and 2 on fuel oil.

Crude after pre-heat train at 580 0f enters in furnace, and after heating it gives the product of about 7000f.

FRACTIONATING COLUMN:-

A fractionating column or fractionation column is an essential item used in the distillation of liquid mixtures so as to separate the mixture into its component parts, or fractions, based on the differences in their volatilities.

Crude distillation unit is the soul of any type of refinery.

In byco ORC-2, cdu column contain 37 plates, in which 4 plates of bottom of stripping section are sieve plates, 4th one is feed plate or flash zone, and remaining 33 are movable valve plates.

Different products at different temperatures at different plates are achieved as mentioned above.

NAPTHA HYDRO TREATING UNIT:- It is a catalytic chemical process which is widely used to remove sulfur, oxygen, nitrogen and other metal content. This unit is also called Hydro-desulphurization unit.

The over head stream from plant-1 contain organic impurities i.e. wide range of organic sulfur compounds, including thiols, thiophenes, organic sulfides and disulfides, mercuptants and many others.

It is important to remove organic impurities from the overhead stream containing naphtha, gasoline, LPG and other lighters because these contents are highly poisonous to the catalyst used in the Plat former unit and Isomerization unit which is used to increase the octane number.

SURGE DRUM:-

The overheads from the crude column enter feed surge drum. Surge drum is a vessel used helps in giving proper suction head and it maintains the N.P.H.S. the water vapors present in naphtha also remove in this vessel. Compressed hydrogen gas is mix with naphtha before entering the pre heat exchangers train and then send to the furnace. Furnace:-

The feed is further heated into the furnaces to get the required temperature for the catalytic reaction in the reactor. At this point the feed almost 95 % vapors and 5% of liquid and its temperature is about 300-350°C and it was fed to the reactor.

FIXED BED CATALYTIC REACTOR:-

The reactor used in this unit is Fixed Bed Catalytic Reactor in which catalyst is used to increase the reaction time. The nature of bed in the reactor is fixed. The fixed bed comprised of three layers; move from bottom to top there was a bottom layer of ceramic balls of four different sizes. The difference of sizes is used to increase the residence time and for proper distribution of feed and to avoid channeling. After this there was a bed of catalyst i.e. Cobalt and Molybdenum. And at the top again there was a layer of ceramic balls of different sizes. At top the reactor is vacant up to the certain height for giving the proper area to spread over the layer of ceramic balls otherwise channeling starts. The feed stock contains a wide range of organic sulfur compounds, including thiols, thiophenes, organic sulfides and disulfides and many others. In this reactor feed stock is converted into H2S, NH3 and water due to sulfur, nitrogen and oxygen respectively. The reaction is both exothermic and endothermic but the net result is endothermic as the temperature drop is minute. The important factor in fixed bad reactor is the catalyst regeneration which was depends upon pressure drop. The pressure drop across reactor could not exceeds to 1 if it did then it indicates that the life of catalyst is over and we have to re generate it. This problem is also occurring if scaling of ceramic balls takes place. If compressors face sudden electricity dip then pressure in the reactor also drop due to which carbon starts deposits on the ceramic balls which causes to increase the pressure difference of reactor.

REACTIONS INVOLVED IN HYDROTREATING UNIT:-

Desulfurization:-

• Mercaptans RSH + H2 RH + H2S

• Sulphides R2S + 2H2 2RH + H2S

• Disulphides RS2 + 3H2 2RH + 2H2S

Deoxidation:-

• Phenol C6H5OH + H2 C6H6 + H2O

• Peroxides C7H13OOH + 3H2 C7H16 + H2O

Denitrogenation

• Pyrole C4H4NH + 4H2 C4H10 + NH3

• Pyridine C5H5N + 5H2 C5H12 + NH3

Other reactions include hydrocracking, DE halogenation and hydrogenation. These reactions are both endothermic and exothermic but the overall effect is exothermic thereby increasing the temperature slightly. The quantity of sulphur is reduced from 1200 ppm to <200 ppm. The gases obtained from the reactor are H2S, ammonia, hydrogen and water vapors which are then removed in separating vessels.

PFD of NHT unit:-

GAS PLANT:- The purpose of gas recovery plant is to separate the light ends from various other refining units into specific materials such as propane and butane. The other function is to remove the light ends from the naphtha fraction of crude to produce the most useful feedstock for the platformer.

There are four streams fed to the gas plant-naphtha from the naphtha HTU, the over head liquid stream from the platformer depentanizer, the gas stream from the distillate HTU stripper.

The purpose of this unit is to separate the ethane and lighter products from the heavy naphtha. The naphtha from the hydrotreater unit is then fed into the de- ethanizer column. In this unit ethane and lighter products are separated from heavy naphtha along with some hydrogen sulphide (H2S). The top product ethane and methane are used as fuel gas in furnaces and boilers. The de-ethanizer column operates at an overhead accumulator of below 450psia at 100oF. The bottom product is C3 and above naphtha.

DE-ETHANIZER:-

The word 'De-ethanizer' stands for the recovery of the ethane from the available feed. The unit configurations would be different in specific applications. The ethane from natural gas is recovered in NGL fraction unit in a LNG train i.e. the demethanizer column bottoms mainly C2+ and very less in C1 are fed to NGL fractionation train where you separate the these liquids. This is the typical recovery under the cryogenic temperatures. Even in LNG you find the substantial quantity of the Ethane.

DE-BUTANIZER:-

The bottom product from the De-ethanizer column is then fed into the De- butanizer column for further separation of lighter products. In De-butanizer the Butane and lighter products are withdrawn as the top product along with hydrogen sulphide (H2S). LPG’s and H2S is then send to the amine treatment plant. Some of this condensate is returned as reflux. The botanizer has a reboiler, which uses 200 psig streams as the heating medium. The bottom product from de-butanizer passes into de-isohexanizer.

DE-ISOHEXANIZER:-

The bottom product containing C5 and higher hydrocarbons from the de-butanizer column is then fed into the de-isohexanizer column. In this column

iso-hexanes and pentanes are separated as the top product along with iso-butane. This top product is used as the feed for isomerization unit. And the remaining is bottom product contains C7 and higher hydrocarbons used as a feed forplatforming unit

ISOMERIZATION UNIT:- Improving C5/C6 naphtha cut octane numbers up to 92 represents an increasingly applied solution to resolve the evolving gasoline pool equation. The isomerate product is free of sulfur, aromatics and olefins, making it a premium gasoline pool blending component. Strengthening regulation towards benzene content in gasoline result in increased quantities of light naphtha when benzene precursors are removed from reformer feed stocks.

Feed Preparation:-

Feed from Gas plant is introduced Coalescer for moisture removal & than passed through heat exchanger trains & finally through Sulfur Guard Bed for removal of Sulfur. Sodium Zeolite is used in this Sulfur removal. Than feed is passed through Dryers & Feed Surge Drum & sent in the PENAX unit.

PANEX UNIT:-

The isomerization unit is specifically designed to for the continues catalytic isomerization of paraffins. The pentane from the de-isohexanizer unit is used as a feed for the isomerization unit. Water must be removed from feed as water is poison to catalyst. Reaction takes place in the excess of hydrogen which must also to be dried. Two reactors are used to convert maximum n-paraffin into i-paraffin in the penex unit. It is first passed through a filter unit.

MOLEX UNIT:-

The Molex feed is normally pumped to the from the upstream penex stabilizer bottom, through chloride guard bed. Chloride guard bed is used to remove chloride from the Molex feed. In Molex unit actually we do the separation processes.

UTILITIES:-REVERSE OSMOSIS PLANT:-

Reverse osmosis plant

Osmosis is the name of a natural process, in which water with lower TDS would travel to the water with higher TDS, if they are separated by a semi-permeable membrane. While in Reverse Osmosis process, the water with higher TDS is made to travel (under pressure) to the water with lower TDS, if they are separated by a semi-permeable membrane.

Schematics of a reverse osmosis system (desalination) using a pressure exchanger.

1: Sea water inflow,

2: Fresh water flow (40%),

3: Concentrate flow (60%),

4: Sea water flow (60%),

5: Concentrate (drain),

A: Pump flow (40%),

B: Circulation pump,

C: Osmosis unit with membrane,

D: Pressure exchanger

Types of RO scheme:-

It is divided into three main sections:

Primary treatment

Secondary treatment

Tertiary treatment

Cooling tower:

Cooling towers are devices which remove heat from a medium and reject this heat to the atmosphere. The basic principle of cooling tower is that of

evaporate condensation and exchange of sensible heat.

TYPES OF COOLING TOWER

Natural draft cooling tower

Mechanical draft cooling tower

NATRUAL DRAFT COOLING TOWER

In natural draft cooling tower air flow is due to largely difference in density between the warm air in the tower and the external embient air. It has two types;

Cross flow NDCT

Counter flow NDCT

MECHANICAL DRAFT COOLING TOWER

Large fans to draw air through circulated water. It has further two types:

Forced draft cooling tower

Induced draft cooling tower

APPROACH OF COOLING TOWER

The approach is the difference in temperature between the cooled-water temperature and the entering air wet bulb temperature. It is outlet temp – wet bulb temp.

RANGE OF COOLING TOWER

The range is the temperature difference between the water inlet and exit states. Inlet temp –outlet temp.

WET BULB DEPRESSION

The wet bulb temperature is the difference between the dry-bulb temperature and the wet-bulb temperature. If there is 100% humidity, dry bulb and the wet-bulb temperatures are identical, making the wet-bulb temperature equal to zero in such conditions.

BOILERS

A boiler is a closed vessel in which water or other fluid is heated. Two types of boilers are used in BPPL.

Water tube boiler

Fire tube boiler

DEARATOR

A DE aerator is a device that is widely used for the removal of oxygen and other dissolved gases from the feed water to steam-generating boilers. In particular, dissolved oxygen in boiler feed water will cause serious corrosion damage in steam systems by attaching to the walls of metal piping and other metallic equipment and forming oxides (rust). Dissolved carbon dioxide combines with water to form carbonic acid that causes further corrosion. Most DE aerators are designed to remove oxygen.

THANKYOU.