S01 MEA

GL1.Z COMPLEX - SONATRACH

PROCESS OPERATING MANUAL

GAS PRE-TREATMENT

« MEA-CO2 REMOVAL »

SECTION N o 1 ~ REVISION N o 2

GL1.Z RENOVATION PROJECT

TABLE OF CONTENTS

1.0 GENERAL OVERVIEW.....................................................................................1

1.1 Location in the Train.......................................................................................1

2.0 OPERATING PRINCIPLES..............................................................................1

2.1 Process Description.........................................................................................12.1.1 Natural Gas Feed.....................................................................................12.1.2 MEA/CO2 Removal System.......................................................................22.1.3 MEA Flash Drum.....................................................................................52.1.4 MEA Regenerator System.........................................................................52.1.5 MEA Filtration System.............................................................................92.1.6 MEA Purification System.........................................................................92.1.7 MEA Storage and Sump System..............................................................102.1.8 Chemical Injection System......................................................................11

2.1.8.1 Anti-foam Injection..........................................................................112.1.8.2 Corrosion Inhibitor..........................................................................11

3.0 PREPARATION FOR START-UP....................................................................11

3.1 Chemical Cleaning.........................................................................................113.1.1 General Information................................................................................123.1.2 Alkaline Preclean Solution......................................................................123.1.3 Acid Cleaning Solution............................................................................13

3.2 Nitrogen Purging............................................................................................143.2.1 General....................................................................................................143.2.2 Inerting Procedure..................................................................................15

3.3 Preparation and Inventory of the MEA Solution............................................153.3.1 Preparation of 20% MEA into Storage Tanks.........................................163.3.2 Inventorying the MEA/CO2 Removal System..........................................17

3.4 Introduction of Natural Gas to the CO2 Absorber System..............................183.4.1 General....................................................................................................183.4.2 System Preparation.................................................................................183.4.3 Valve Positions, CO2 Absorber...............................................................183.4.4 Natural Gas Pressurisation.....................................................................19

3.5 MEA Circulation.............................................................................................193.5.1 Preparing MEA Solution pumps X01-J-503/504.....................................19

4.0 NORMAL START-UP........................................................................................21

4.1 HOT MEA Circulation....................................................................................214.1.1 Prerequisites for Start-up........................................................................214.1.2 CO2 Absorber and MEA Flash drum.......................................................214.1.3 Starting the MEA Solution pumps...........................................................224.1.4 Establishing Hot Circulation..................................................................24

4.1.4.1 Commission Steam to X01-E-506 Gas pre-heater...........................24

4.1.4.2 Commission Steam to X01-E-502 Regenerator Reboiler................244.1.4.3 Starting the MEA Purifier................................................................254.1.4.4 Injecting Anti-foam Solution............................................................27

4.2 Establishing Natural Gas feed through the CO2 Absorber.............................29

5.0 NORMAL OPERATION....................................................................................30

5.1 Normal Operating Parameters.......................................................................305.2 Feed Stream Composition...............................................................................325.3 Product Stream Composition..........................................................................33

6.0 OPERATING VARIABLES...............................................................................34

6.1 Internal Variables...........................................................................................356.1.1 CO2 Absorber Overhead Product............................................................356.1.2 MEA Regenerator....................................................................................35

6.2 External Variables..........................................................................................356.2.1 Site Temperature.....................................................................................356.2.2 Feed Gas Composition............................................................................36

7.0 PROCESS CONTROL.......................................................................................36

7.1 Natural Gas Feed...........................................................................................367.2 Absorber Contacting Section..........................................................................377.3 MEA Circulation and Regeneration...............................................................39

7.3.1 MEA Flash Drum....................................................................................397.3.2 Regenerator Column...............................................................................407.3.3 MEA Solution Pumps X01-J-503/504.....................................................427.3.4 MEA Filtration........................................................................................447.3.5 MEA Purification....................................................................................447.3.6 Chemical Injection..................................................................................457.3.7 MEA Storage...........................................................................................45

7.3.7.1 MEA Sump X01-G-504....................................................................457.3.7.2 MEA Sump pump X01-J-505...........................................................467.3.7.3 MEA Storage Tanks 201-G-501/401-G-505....................................46

8.0 NORMAL SHUTDOWN....................................................................................48

8.1 Stopping Feed Gas Flow................................................................................488.2 Shutdown the MEA Purifier............................................................................498.3 Shutdown the MEA Regenerator....................................................................498.4 Draining the Absorber and Regenerator system............................................50

8.4.1 Draining the MEA Regenerator to Storage.............................................508.4.2 Draining the CO2 Absorber to Storage...................................................50

9.0 SHORT TERM SHUTDOWN............................................................................51

10.0 QUALITY CONTROL........................................................................................52

11.0 PROTECTIVE SYSTEMS AND EMERGENCY SHUTDOWN......................53

11.1 Shutdown Systems...........................................................................................5411.1.1 ESD System..............................................................................................54

11.1.2 Primary Protection System..............................................................5611.1.2.1 CO2 Absorber...................................................................................5611.1.2.2 MEA Regenerator............................................................................56

12.0 SAFETY HAZARDS..........................................................................................57

12.1 General...........................................................................................................5712.2 Monoethanolamine (MEA).............................................................................58

12.2.1 Flammability...........................................................................................5812.2.2 Handling and Safety Precautions............................................................5812.2.3 Safe Handling..........................................................................................59

12.3 Combustible Mixtures.....................................................................................5912.3.1 Ventilation and Cleaning of Vessels and Lines.......................................59

13.0 APPENDICES....................................................................................................60

13.1 DCS Schematics..............................................................................................6013.2 Process Flow Diagrams (PFD's)....................................................................6013.3 Process and Instrument Diagrams (PID's).....................................................6013.4 Cause and Effect Charts.................................................................................60

June 2001 Page 10 of 60Rev 2SECTION – 1


MEA-CO2 REMOVAL

1.0 GENERAL OVERVIEW

1.1 Location in the Train

The MEA-CO2 removal section is located in each individual LNG train. It is the first section that the feed gas enters in the LNG process.

The purpose of the MEA system is to remove the Carbon Dioxide (CO2) from the incoming feed gas before it enters the Cryogenic section of the process. It is necessary to remove the CO2 from the feed gas in order to prevent freezing of the CO2 at low temperatures in the cryogenic section.

CO2 removal from the feed gas using MEA solution as an absorbing medium is based on the principal that at high pressure and low temperature the CO2 molecules are attracted to the MEA molecules (RNH2) and combine with them according to the following chemical reaction (moving left to right).

2RNH2 + H2O + CO2 < > (RNH3)2 CO3 + Heat

During the regeneration, process the chemical reaction is reversed, (from right to left).

A 15-20% Monoethanolamine, (MEA) solution is utilised to absorb the Carbon Dioxide (CO2) in the incoming natural gas stream.

A high concentration of CO2 in the outlet of the MEA section could result in freezing problems in the gas chillers and the Main Heat exchanger

2.0 OPERATING PRINCIPLES

2.1 Process Description

2.1.1 Natural Gas Feed

The natural gas feed enters the GL1Z complex from Hassi R'Mel via (2) 42" parallel pipelines. The quantity of gas delivered is dependent upon the production demands of the facility. Inside the GL1Z battery limit, these 2 pipelines join a common 42" distribution header, which distributes the gas to the following users:

The six LNG trains for LNG production via (6) 20" supply headers.

The common fuel gas distribution header to supplement the fuel gas requirements for the boilers during periods of increased demand



MEA-CO2 REMOVAL

The following instruments and controls are provided on the common header:

A 42" (normally fully open) fire valve JV-000-04 that uses natural gas as motive power. This valve requires a minimum upstream pressure of 19.68 Bar for the valve to operate. It takes approximately 30 seconds to open or close. JV-000-04 can be opened and closed locally by (2) hand switches (HS-000-04A/B). This valve is also connected to the ESD system and can be closed via a push button (HS-000-04C) on the ESD panel in the CCR. JV-000-04 is also equipped with a 3" bypass line for pressurisation purposes prior to valve opening. (2) valve position indicators (ZLO-000-04 / ZLC-000-04) as well as valve "tripped" alarm (XA-000-04) are displayed on the DCS in the CCR.

A 2" normally closed drain line to the hydrocarbon decanter system, which is used to drain entrained liquid from the header.

A local pressure indicator (PI-000-07A) and DCS display (PI-000-07) with associated high/low alarms.

An analyser unit (Gas chromatograph) AE-940-38. This analyser sends a density correction signal (AI-940-38) to FR-X01-05 in the CO2 removal section via the DCS in the CCR. A local sample connection is also provided.

2.1.2 MEA/CO2 Removal System

The feed gas enters the MEA absorber (X01-F-502) bottom section through 20" PRG-X0110-904. This line is equipped with an ESD valve; JV X01-70, and a pressure controller, PIC X01-04, which maintains constant feed gas pressure in the MEA absorption column. The bottom section serves as a liquid separation vessel removing any entrained hydrocarbon liquid from the feed gas stream. This liquid is then level controlled to the Hydrocarbon decanter system.

The gas stream passes through a mist eliminator to further remove any liquid carryover prior to entering the feed gas pre-heater. The gas then flows through the tube side of the Feed Gas Preheater (X01-E-506) where the gas temperature is adjusted utilising 3.45 Barg 150°C saturated steam prior to entering the MEA absorption column. 62 Barg steam is also injected on the outlet of X01-E-506 to control the water balance in the MEA column.



MEA-CO2 REMOVAL

The MEA absorption column, (X01-F-502) contains 27 single pass valve trays. The bottom 25 trays are the amine absorption, (contacting) section, with the top 2 trays, being the overhead wash section. The natural gas enters the column under Tray 27 and passes upward through the column, counter-current to the Lean (15-20%) aqueous MEA solution descending through the column. The target for the residual CO2 content in the overhead stream is 10 ppm with a maximum of 90 ppm.

CO2 removal from the feed gas using MEA solution as an absorbing medium is based on the principal that at high pressure and low temperature the CO2 molecules are attracted to the MEA molecules (RNH2) and combine with them according to the following chemical reaction (moving left to right).


During the regeneration, process the chemical reaction is reversed, (from right to left).

The CO2 (rising) is absorbed by the MEA solution (descending) and collected in the bottom of the absorber, (Rich) prior to being level controlled out to the amine regeneration system.

The overhead gas being free from CO2 passes through the wash section, trays 1 & 2, where it is washed with demineralised water to remove any MEA that is entrained in the gas stream. The resultant gas then flows through a mist eliminator to further remove any liquids that could be carried overhead with the gas stream.

The overhead gas stream flows via 20"PRG X0113-904 to the Drier Pre-cooler (X04-E-5.21) where it is cross exchanged with liquid propane from the Propane refrigeration system, prior to entering the gas Drier section.

(Rich) MEA solution leaves the bottom of X01-F-502 through 4" MEAR-X01201-904A and enters X01-G-507 (MEA Flash Drum). Any hydrocarbon vapours are flashed from this drum to the Fuel Gas system. This MEA solution then passes through X01-E-503B/A tube side, where it is cross-exchanged with (Lean) MEA solution exiting the bottom of X01-F-501 (Amine Regenerator).



MEA-CO2 REMOVAL

Column CharacteristicsMEA Absorber X01-F-502(Contacting section)Type Vertical ColumnTrays 27 (Valve) + 1 (Chimney)Design pressure 49.7 BarOperating pressure 41.2 BarDesign temperature 82° COperating temperature 38° CFlow rate 267,000 Nm3/h (H)

278,000 Nm3/h (L)MEA 61,000 kg/hr

Vessel CharacteristicsFeed Gas separator (lower part of the Absorber column)Type Vertical vesselDesign pressure 49.7 BarDesign temperature 82° COperating temperature 0-50° CFlow rate 267,000 Nm3/h (H)Vapour 278,000 Nm3/h (L)

Exchanger CharacteristicsFeed gas Pre-heater X01-E-506Type Horizontal tube and shell

Shell sideFluid Saturated steam/condensateDesign pressure 10 BarDesign temperature 177° COperating pressure 3.5 BarOperating temperature (In) 150° (Out) 130°Flow rates 10,184 kg/hr (H)

10,090 kg/hr (L)

Tube sideFluid Natural GasDesign pressure 49.7 BarDesign temperature 52° COperating pressure 41.2 BarOperating temperature (In) Ambient / (Out) 38° CFlow rates 267,000 Nm3/h (H)Vapour 278,000 Nm3/h (L)Number of tubes 186 (1/4")Number of passes 1



MEA-CO2 REMOVAL

2.1.3 MEA Flash Drum

The function of the MEA flash drum is to eliminate all hydrocarbon contaminants from the "Rich" MEA solution which otherwise would cause foaming in the regenerator column.

The rich MEA solution from the Absorber is directed under level control by LIC-X01-21 to the MEA flash drum. The wash water section outlet LIC-X01-204 also ties into the inlet of the MEA flash drum downstream of LV-X01-21. Across LV-X01-21, the pressure is reduced from 41 Bar to 8 Bar. This causes the light hydrocarbons to flash off and create a vapour space in the drum, which is used to control the liquid level. The vapour pressure is used by PIC-X01-215 to control the flash drum pressure at 8 Bar by actuation of PV-X01-215. Excess pressure is routed to the fuel gas system.

Rich MEA liquid is level controlled from the flash drum to MEA regenerator by LIC-X01-218 after passing through the tube sides of exchangers X01-E-503B/A respectively. The rich amine is preheated in these two exchangers by lean amine exiting X01-F-501 on the shell side.

Heavy hydrocarbons on top of the amine solution can be "skimmed" over a 1110 mm Weir and collected in a separate compartment and sent to the hydrocarbon decanter as required. 2 sample valves are provided on the side of the flash drum for determining the presence of heavy hydrocarbons, at 900 mm and 1000 mm. If hydrocarbons are detected the level can be raised to direct them over the weir and then sent to the decanting system.

Vessel CharacteristicsMEA Flash Drum X01-G-507Type Horizontal vesselInternal volume 14.67 m3

Maximum Allowable Pressure 12 BarOperating pressure 8 BarDesign temperature 147° COperating temperature 43° C (H) 47° C (L)Flow rates 62,612 kg/hr (H)

61,910 kg/hr (L)

2.1.4 MEA Regenerator System

The function of the MEA regenerator is to remove the CO2 from the rich MEA solution. This is achieved by reversing the chemical reaction, which caused the CO2 in the feed gas to be absorbed by the MEA, moving from right to left.




MEA-CO2 REMOVAL

X01-F-501 (Amine Regenerator) contains 21 single pass valve trays. Rich MEA exits X01-E-503A tube side at 93° C and enters the MEA regenerator on tray 1 via LV-X01-218. Initially a large portion of the CO2

flashes due to the pressure drop across this valve from 8 Bar to 0.7 Bar and exits the column overheads to the Acid Gas separator. The MEA solution descends through the trays and the remaining CO2 is stripped by the hot vapour rising through the column.

The stripping steam is produced in the MEA reboiler by vaporizing a part of the MEA solution entering the reboiler after collection on tray 21.The liquid flows into the shell side of the reboiler and is heated by 3.45 Barg 150° C steam. An overflow weir ensures the tube bundle is completely covered with MEA solution at all times, for maximum efficiency and protection against overheating. Thermo-syphon effect is used to direct the vaporized portion of the MEA solution back to the Regenerator column under tray 21. The non-vaporized portion of the MEA solution overflows the weir into the bottom of the regenerator column.

Exchanger CharacteristicsMEA Recoiled X01-E-502Type Kettle recoiled

Shell sideFluid Lean MEAPressure 0.7 BarTemperature 118 °CFlow 61,533 kg/hr

Tube sideFluid L.P. SteamPressure 3.45 BarTemperature 150 °CFlow 6977 kg/hr

The bottom section of the MEA regenerator provides many functions. It is a mixing vessel, a pump suction drum, MEA solution reservoir, and a separator. The main functions are:

To separate the two-phase vapour/MEA mixture from the reboiler outlet into stripping steam and lean MEA.

To collect the lean MEA from the reboiler.

To provide mixing space for the incoming MEA solution and condensate streams.

To provide suction capacity for the MEA solution pumps.

To provide inventory for the MEA system.



MEA-CO2 REMOVAL

The 15-20% makeup solution is injected into the outlet of the regenerator bottoms, so not to disturb the temperature profile of the column bottom section.

The regenerator bottoms level is not controlled directly as it has enough capacity to compensate for occasional level changes and fluctuations due to flow adjustments, level controller response time or foaming conditions.

The MEA regeneration and circulation system is a Closed Circuit, and once the normal operating levels and pressures have been established in the Absorber, Flash drum, and the Regenerator the bottoms level should remain relatively stable.

The bottoms of the regenerator column enter the shell side of X01-E-503A/B exchangers where the lean MEA is cooled to approximately 71° C by the Rich MEA on the tube side entering the regenerator column. Temperature indicator TI-X01-109 on the outlet of X01-E-503B monitors the lean MEA temperature. TAL-X01-109 (low temperature alarm.) set at 62° C and TAH-X01-109 (high alarm) set at 78° C provide monitoring of the lean MEA solution.

The function of the MEA solution pumps X01-J-503/504 is to return the Lean MEA solution to tray 3 of the Absorber column. In order to do this the pump must increase the pressure from 0.7 Bar to 52 Bar to overcome the Absorber pressure (41 Bar), and friction losses in the piping.

Two solution pumps are provided, one driven by a steam turbine (X01-J-503T) using 16.2 Bar and 221° C superheated steam. The other, (X01-J-504) driven by an electric motor (380 Volt AC). Normally the turbine driver is in service with the electric driven pump in Auto/standby. PAL-X01-62 (low discharge pressure) on X01-J-503 will automatically start the standby electric pump (X01-J-504) at 35 Bar (decreasing) pressure to maintain MEA flow to the absorber column.

Pump CharacteristicsMEA Solution pumps X01-J-503/504Type Centrifugal Horizontal 6 StagesManufacturer Byron JacksonDischarge Pressure 52 BarSuction Pressure 0.7 BarOperating Temperature 69° CFlow rates 61,000 kg/hr (H/L)Normal Flow 54.7 m3/hrCapacity 63 m3/hrSpeed 3910 RPM



MEA-CO2 REMOVAL

Driver CharacteristicsX01-J-504 Electric MotorMotor Power 250 HPCurrent 380 Volt (AC) 3 phase 50 HzMotor speed 1470 RPMIncreasing Gear 1470-3910

X01-J-503T Steam turbine (single stage)Turbine power 250 HP (186 kW)Turbine speed 3910 RPMSteam Inlet pressure 16.2 BargSteam inlet flow 7401 kg/hr 221° CTurbine exhaust pressure 3.5 Barg (150° C)

MEA Solution Cooler X01-E-504

The function of the MEA solution cooler X01-E-504 is to further cool the lean MEA from 70° C to approximately 40° C at the absorber inlet. The MEA solution must be 2° C higher then the gas temperature in the column to prevent condensation at the point of contact. Lean MEA flows through the shell side of X01-E-504 and is cooled by seawater passing on the tube side. A 3" bypass line is provided on the MEA piping to allow manual temperature control during periods of cold weather. A high temperature alarm TAH-X01-103 set at 42° C is provided on the outlet of the cooler for monitoring purposes.

A minimum flow line to the pump suction with a control valve FV-X01-76 is provided on the outlet of the cooler for solution pump low flow protection. FIC-X01-76 operates on FV-X01-76 and is set at 27,000 kg/hr. Minimum flow protection is required for pump start-up and shutdown conditions. A check valve downstream of the cooler provides reverse flow protection from the absorber to the regenerator column.

Lean MEA flow is directed to tray 3 on the absorber column via FV-X01-29 controlled by FIC-X01-29. Normal MEA flow is set at approximately 54,700 kg/hr.

The MEA regenerator overhead is comprised mainly of CO2 (10-19%) and water vapour (81-89%). The overhead vapour leaves the top of the MEA regenerator column and enters the shell side of the overhead condenser, X01-E-501 where it is cooled by seawater. The seawater flow is controlled manually by a ball valve placed in the supply to the exchanger. Two restriction orifices are placed in series downstream of the exchanger to maintain cooling water backpressure across the condenser.

A controlled amount of corrosion inhibitor is injected upstream of the condenser to neutralize the acidity of the overhead stream. The



MEA-CO2 REMOVAL

condensed liquid is collected in the acid gas separator, X01-G-502 and is pumped by X01-J-506 to the sump of the MEA regenerator.

The non-condensable vapour, mainly carbon dioxide (CO2) is vented to atmosphere from the acid gas separator via pressure control, PIC-X01-07 that maintains a constant pressure on the MEA regenerator column.

2.1.5 MEA Filtration System

Lean MEA filters, X01-P-501 (Carbon) and X01-P-502A/B/C (Cartridge) are provided for the removal of solid impurities from the MEA solution, that if allowed to accumulate could cause foaming and plugging of the trays in the MEA absorption and regeneration columns.

A slipstream of MEA, approximately 4% of the total flow to the MEA absorber is taken off upstream of FV-X01-29. It passes through cartridge filter (X01-P-502A) to remove any solid particles greater then 5 micron. The solution then passes through a bed of activated carbon, (X01-P-501) which removes any compounds that could cause foaming in the MEA columns. It is then passed through another cartridge filter (X01-P-502B) to remove any carbon particulate and rejoins the lean MEA stream downstream of FV-X01-29 on the inlet of the MEA absorption column.

The normal pressure drop across each of the 3 filters is 0.5-0.7 Bar. Cartridge filter change is required at 1-1.4 Bar. When the differential pressure across the carbon filter is greater then 1.4 Bar, the bed must be replaced. Local pressure indications, PI-X01-73/47 are provided for differential pressure monitoring.

Another slipstream of lean MEA, (approximately 10% of total flow) is drawn off upstream of FV-X01-29 and passes through cartridge filter (X01-P502C) before returning downstream of FV-X01-29. The normal pressure drop across this filter is 0.5-0.7 Bar. The filter element must be replaced at 1.4 Bar.

2.1.6 MEA Purification System

Although corrosion inhibitor is added into the MEA Regenerator overhead system to neutralise the vapour containing CO2, other corrosion problems are often caused by poor maintenance of the amine solution.

The purpose of the MEA purifier, X01-E-505 is to remove any impurities caused by the oxidation and degradation of the amine solution, which could lead to corrosion problems within the system. These impurities are non-volatile and can be separated from the amine by distillation.

A small slipstream of amine is drawn from the bottom tray of the MEA regenerator column by level control, LV-X01-01 on (X01-E-505) to maintain the liquid level above the tube bundle. The MEA solution is



MEA-CO2 REMOVAL

heated by 10.3 Barg, 212° C steam on the tube side of X01-E-505. Amine solution is admitted to the purifier at the same rate of the vapour boil-off. This vapour leaves the purifier and re-enters the MEA regenerator column under tray 21.

During the distillation process in the purifier, the acidic components in the MEA solution form salts with the sodium carbonate added to the purifier at the start of each cycle. The salts, together with other degradation products form sludge, which accumulates in the tube bundle of X01-E-505. They can be drained, or washed out by using steam condensate at the end of each purification cycle indicated by high temperature, +150° C on X01-E-505.

The MEA Purifier should be placed in service as soon as possible after establishing amine circulation.

2.1.7 MEA Storage and Sump System

MEA solution (20%) concentration is stored in two tanks, 201-G-501 and 401-G-505. Tank 201-G-501 provides the inventory and make-up requirements for Trains 100/200/300, with Tank 401-G-505 providing inventory and make-up for Trains 400/500/600.

Each tank is supplied with a Nitrogen connection to maintain positive pressure to prevent the ingress of air into the tanks. The tanks are also provided with a 3.5 Barg steam heating coil to prevent the amine solution from solidifying should the amine concentration become too high.

Each individual CO2 removal section has a sump X01-G-504 equipped with a pump, X01-J-505. This sump system is used for transferring Amine solution and diluting amine with condensate for make-up into the system. The MEA sump is also used for collecting MEA, which is drained from various equipment in the unit:

MEA Regenerator X01-F-501

Reboiler X01-E-502

MEA Exchanger X01-E-503

MEA Absorber X01-F-502

Carbon Filter X01-P-501



MEA-CO2 REMOVAL

Sump pump X01-J-505 can transfer amine to the specific unit amine system, the amine purifier, another process train, or the amine storage tank.

2.1.8 Chemical Injection System

2.1.8.1 Anti-foam Injection

Anti-foam solution is injected into the system at a very low rate to control the foaming phenomenon in the CO2 removal system. Excessive injection of anti-foam chemicals can actually aggravate the foaming condition.

Foaming can result from rapid changes in the system flow rates or by a build-up of impurities within the system. The purification and filtration systems should always be in service to maintain the amine solution.

Foaming is indicated by:

High differential pressure across MEA Absorber X01-F-502

High differential pressure across MEA Regenerator X01-F-501

An increase in liquid carryover from MEA Absorber X01-F-502

Large fluctuations in Absorber and Regenerator column levels.

2.1.8.2 Corrosion Inhibitor

Corrosion inhibitor injected into the regenerator overhead line is required at intervals dictated by analysis, experience, corrosion probes, etc to neutralize the acidity of the vapour leaving the regenerator for the protection of downstream piping and equipment. The injection target is to establish and maintain an inhibitor concentration of 300-450 ppm per volume of MEA in the system.

The recommended corrosion inhibitor is, Type 9-RB-819-N.1 (Nalco Italiana)

3.0 PREPARATION FOR START-UP

3.1 Chemical Cleaning

The following procedure is recommended for cleaning carbonate scale greases and corrosion products from the MEA system.

Alkaline pre-cleaning is required when the internal equipment and piping surfaces of the CO2 removal system is believed to be coated with oil or greasy substances. Without chemical cleaning, the oil and grease would remain in the system and could contribute to foaming throughout the MEA system.



MEA-CO2 REMOVAL

3.1.1 General Information

Acid used will be 3-3.5% by weight , ammoniated citric acid with a Ph of 3.5

System inventory is approximately 33 m3. The system will be under 28 bar natural gas pressure. MEA cartridge filters are to remain installed during the procedure. The carbon must be removed from the carbon filters. Soda ash is to be removed from the MEA purifier. Temporary screens are to be installed in the suction of the MEA

pumps. Proper safety equipment must be used. Seawater is to be isolated on the MEA cooler. The capacity of the MEA sump is approximately 3.2 m3

The solutions will be mixed in the MEA sump until all the ingredients are in solution. 10 to 11 sumps will be required to load the system to normal inventory.

3.1.2 Alkaline Preclean Solution

Ingredients required for mixing one sump load:

Hot condensate 2840 litres Tri-sodium phosphate 70 kg Sodium hydroxide 70 kg Sodium nitrate 27 kg Aqua ammonia (28%) 190 litres Laundry detergent (teldj) 31 kg

1. Fill the MEA sump with condensate and slowly add the Trisodium phosphate, sodium hydroxide and sodium nitrate.

2. Circulate the sump on recycle to ensure adequate mixing.

3. When the solution is mixed, add ammonia and the detergent.

4. Add the sump to the amine system. Repeat until 10-11 sumps are added.

5. Start an amine circulation pump and circulate the system for 15 minutes.

6. Commission the steam to the regenerator reboiler and increase the solution temperature to between 80-90° C.

7. Drain the system to the sewer

8. Refill the entire system with clean condensate and circulate for 15 minutes.



MEA-CO2 REMOVAL

9. Drain the system to sewer.

3.1.3 Acid Cleaning Solution

Ingredients needed for mixing one sump load:

Hot condensate 2840 litres Citric acid 100 kg Ammonium hydroxide (20%) 114 litres

1. Fill the sump with 2840 litres of condensate.

2. Slowly add the citric acid until it is dissolved.

3. Circulate the sump on recycle to ensure adequate mixing.

4. Add the ammonia to adjust the pH to 3.5.

5. Fill the MEA system with10-11 sumps of the acid solution.

6. Ensure the absorber pressure is approximately 28 bar with natural gas.

7. Set the Regenerator at 0.7 bar with PIC-X01-07.

8. Circulate the amine system, raising the temperature to 90-95° C with the regenerator reboiler.

9. Circulate for 1 ½ hours and check the solution pH.

10.If the solution is above 6 pH, add acid to lower the pH to 4-5.

11.Repeat the above step until the pH remains below 6 for 1 ½ hours.

12.When the acid cleaning is complete, slowly add ammoniac to the system to raise the pH to 9-10.5 and circulate for 2 hours.

13.Drain the system to sewer.

14.Fill the system with condensate, approximately 33 m3 and circulate for 1 hour.

15.Drain to the sewer system.

16.Repeat step 14, adding 176 kg of sodium nitrite to the total condensate solution, (16 kg) per sump.

17.Circulate for 30 minutes.

18.Drain all instrument connections and 'dead' legs. Drain the entire system to sewer.



MEA-CO2 REMOVAL

19. Change the amine cartridge filters.

20.Add charcoal to the carbon filter, after inspecting the internals.

21.Depressure, nitrogen, and air purge the system.

22.Inspect all vessel and tower internals, including the MEA sump.

23.Remove the temporary strainers on the pump suctions.

Total Chemicals required:

Alkaline Preclean

Trisodium phosphate 795 kg Sodium hydroxide 795 kg Sodium (Ammonium) nitrate 310 kg Local detergent (Teldj) 355 kg Aqua ammonia (28%) 2160 litres

Acid Cleaning

Citric, (Sulphonic) acid 1140 kg Sodium nitrite 176 kg Aqua ammonia (28%) 1270 litres.

3.2 Nitrogen Purging

3.2.1 General

Hydrocarbons must never be introduced into the process piping and equipment until all the Oxygen has been removed, (Purged). Otherwise explosive mixtures could be formed. Oxygen removal is accomplished by displacing the air with an inert gas, usually nitrogen gas. Nitrogen purging is most effective utilising the Pressure purge method. Pressurising the selected system to 3 Barg, (several times) while ensuring that no air is trapped in 'dead legs' (blocked pipes or tubing) and then blown to atmosphere in as many points as possible. As Nitrogen is an asphyxiate precautions must be taken to protect personnel during release to atmosphere.

For practical and safety reasons, nitrogen purging should be carried out section-by-section and not the entire train at once. This does not preclude purging several sections at the same time, or starting another section before one section is completed, as long as a positive purge can be completed. In addition, nitrogen used in one section should be whenever possible be utilised to purge the next section in series until the entire train is O2 free. Ideally, only when the last section has been purged should the nitrogen be evacuated to atmosphere.



MEA-CO2 REMOVAL

The first pressure purge cycle should never be evacuated to the Flare system in order to prevent a combustible mixture into the Flare headers. After the oxygen level has been reduced, the purge sequence can be routed to the flare system.

Following chemical cleaning operations the entire MEA/CO2 removal system must be purged with Nitrogen to prevent oxidization and kept under positive nitrogen pressure to prevent Vacuum collapse.

3.2.2 Inerting Procedure

1. Ensure XV-X01-202, 20" overhead block valve on X01-F-502, XV-X01-211, PV-X01-215, and PV X01-07 are closed.

2. Connect a nitrogen hose to the 1" fitting upstream of PV-X01-04

3. Pressurise the system to 2 Barg, from X01-F-502, through the MEA flash drum and into X01-F-501.

4. Open the valves in the system as per normal amine circulation flows.

5. Open the bypass around PSV-X01-30 (Absorber overheads), the bypass around PSV-X01-217 (Flash drum), and the bypass around PSV-X01-14 (Regenerator overheads).

6. Depressure the system to 0.2 Barg.

7. Repeat steps 3 through 6 until the Oxygen level is less than 1% throughout the system. Sampling at AT-X01-38 (Absorber overhead analyser), the MEA flash drum and the Regenerator overheads. Open all level column drains/vents, exchanger vents (High/low points) and pump casings to ensure the system is oxygen free.

It is not critical to have the Regenerator column completely Oxygen free as during normal start-up and operation this column is vented to atmosphere.

8. An initial leak test of the system can be performed at 5 Barg of all flanges and fittings in the section.

9. Leave the system under 0.5 Barg nitrogen pressure in preparation for MEA inventory.

3.3 Preparation and Inventory of the MEA Solution

MEA solution for storage is produced by mixing 100% commercial Monoethanolamine (MEA) with Condensate water to a final solution strength containing 20% wt. of MEA.



MEA-CO2 REMOVAL

Approximately 2m3 of condensate is added to the MEA sump (X01-G-504) via the normal condensate make-up line, to which is added approximately 3 (210 litre) drums of concentrated MEA.

Using the sump pump (X01-J-505) and the recirculation line, the sump is thoroughly mixed to strength of approximately 20% wt. And then transferred to the MEA storage tanks 201-G-501 (Train 200), or 401-G-505 (Train 400) for makeup storage to the process trains.

Each of the MEA storage tanks has a capacity of 45m3, which is sufficient to supply 3 process trains. Tank 201-G-501 supplies Trains 100/200/300, with 401-G-505 supplying Trains 400/500/600. Demineralised water is added at each individual process unit to obtain solution strength of approximately 15% wt. MEA solution. Process train inventory during normal operation is approximately 33m3.

Alternatively, a 15% wt. solution can be prepared in each process train by firstly inventorying the MEA/CO2 system with Demineralised water, as described in Section 3.1 of this manual. Then adding drums of concentrated MEA to the sump and circulating the system until the required MEA % wt. is achieved.

3.3.1 Preparation of 20% MEA into Storage Tanks

1. Commission the nitrogen to the storage tanks. Monitor the nitrogen pressure closely to remain below the set point of 0.5 PSIG on the individual PSE's on the tanks.

2. Start filling the MEA sump with demineralised water. Add approximately 3 drums of MEA to the sump.

3. Check the operation (Auto start/stop) of X01-J-505.

4. Start X01-J-505 on recirculation for 30 minutes. Check the amine concentration and add demineralised water or MEA as required to maintain 20% wt. concentration.

5. Transfer the sump tank to the MEA storage tanks utilising X01-J-505.

6. Repeat steps 2 through 5 until the normal operating level of 70% is in the MEA storage tanks.

7. Commission the heating coil to the MEA storage tanks.



MEA-CO2 REMOVAL

3.3.2 Inventorying the MEA/CO2 Removal System

1. The CO2 Absorber is under 0.5 Barg Nitrogen pressure with the Regenerator column at 0.7 Barg Nitrogen (PV-X01-07 Auto), and PV-X01-215 (MEA flash drum) on Auto at 8.5 Barg.

2. The carbon filter is charged with activated carbon and new filter cartridges are installed in X01-P-502A/B/C.

3. The 20" absorber overhead block valve to the gas driers is blocked in.

4. XV-X01-202, downstream block valve to the hot flare is closed.

5. Block in the absorber wash section outlet block valve to the wash pumps X01-J-510/511. (At the column). Ensure the inlet block valve upstream of LV-X01-212 (MEA flash drum) is closed

6. Start wash water flow through FI-X01-206 to the wash section. Allow the section to overflow to the bottom of the column, until level reaches 30%. Open LV X01-212 and fill MEA flash drum to 70%, maintain absorber level at 30%.

7. Isolate the 4" globe valve downstream of X01-E-503A tube side. Open the drains and vents on X01-E-503A/B.

8. Slowly open the outlet block valve on the amine flash drum. When liquid is detected at the drains and vents, close the valves.

9. Close the downstream block valve on LV-X01-218. Open the ¾" upstream drain valve.

10. Slowly open the 4" globe valve downstream of X01-E-503A until liquid is present at the drain. Unblock LV-X01-218 and set at 60% in Auto.

11. Open the 3" block valve from the MEA storage tank to the MEA sump. Fill to 80% level. Start X01-J-505 (sump pump) and begin to fill the MEA regenerator through 2" MEAL-X0121-903 line.

12. Fill regenerator column to 60%.

13. Open the suction block valves on the MEA solution pumps (X01-J-503/504). Vent the pump casings and Exchanger tube sides to fill with liquid.

14. Fill the Anti-foam and Corrosion Inhibitor tanks using the Condensate supply piping attached to each tank.



MEA-CO2 REMOVAL

15. Fill the MEA filtration system using the Condensate supply piping.

16. The system is now ready to begin Natural gas pressurisation.

3.4 Introduction of Natural Gas to the CO2 Absorber System

3.4.1 General

When the entire train is free of oxygen and under nitrogen pressure, the CO2 Absorber system must be leak tested with natural gas at normal operating pressure. This includes the Absorber column, the Wash water circuit, and the Feed Gas separator.

The MEA Flash drum, the Regenerator system will have been tested during the Inerting procedure described in Section 3.2.

3.4.2 System Preparation

1. Ensure that the process train has been nitrogen purged and is Oxygen free.

2. Ensure the 20" and 1" blinds are removed on the Feed gas inlet upstream of PV-X01-04 at the Battery limits.

3. Ensure the Hot flare system is purged and available and all system PSV's are in service.

4. All automatic Process and Emergency systems for the MEA/ CO2

are in service. (ESD, Fire and Gas Detection, and Fire Water protection systems).

5. Notify all Unit personnel of the introduction of Natural gas.

3.4.3 Valve Positions, CO2 Absorber

All manual and automatic valves in the MEA/ CO2 absorber system, which are not mentioned below, are assumed to be in OPEN position.

PSV by-pass valves.

Drains and vent valves.

Analyser and sample valves.

Instrument and control valve by-pass valves.

Nitrogen and steam out connection valves.

1. 20" Absorber overhead to Dryer section and 1" bypass valves closed.



MEA-CO2 REMOVAL

2. 8" Absorber overhead (Start-up) to Hot flare closed.

3. Absorber overhead XV-X01-202 closed and manual block valve open to the Hot flare.

4. LV-X01-204, and FV-X01-205 (Wash section), block valves closed.

5. FV-X01-29/76 block valves closed.

6. Gas separator to hydrocarbon decanter, Battery limit block valve closed XV-X01-211 open.

7. PV-X01-04 in Manual and closed.

8. 4" downstream block valve on LV-X01-21 (Flash drum inlet) and bypass valve closed.

9. XV-X01-212 (Flash drum inlet), valve open.

3.4.4 Natural Gas Pressurisation

1. Slowly open the 1 ½" bypass globe valve on PV-X01-04 feed gas inlet and pressurise the Absorber system to 10 Barg.

2. Check all flanges, joints, valves drains, control valves, instrument connections, and PSV's for external leaks using tape and a soapy water solution. Also, check valves for internal leakage, if possible.

The nitrogen content in the system is not a concern, as this will be purged to flare during Absorber start-up.

3. Repair any leaks which are present.

4. Continue to raise the gas pressure in increments of 5 Barg until the normal operating pressure of 41 Barg is reached. Check for leaks at each step, and repair as necessary

5. The Absorber can remain at 41 Barg to establish MEA circulation.

3.5 MEA Circulation

3.5.1 Preparing MEA Solution pumps X01-J-503/504

1. Ensure both solution pumps are coupled and have the proper rotation.

2. Ensure all instrumentation is in service and functioning properly.

3. Ensure the pump and motor lubrication levels are correct



MEA-CO2 REMOVAL

4. Ensure the suction screens are installed on both MEA pumps.

5. Ensure the cooling water supply is in service.

6. Ensure the Absorber column is at 41 Barg Natural gas pressure andLV-X01-21 is in Auto and set at 60%.

7. Ensure PV-X01-215 (MEA Flash drum) is in Auto and set at 8.0 Barg. Set LV-X01-218 at 60% and in Auto.

8. Ensure PV-X01-07 Regenerator overheads is in Auto, set at 0.7 Barg.

9. Set FV-X01-76 (MEA Recirculation) in Manual and closed, this is to prevent reverse gas flow to the regenerator in case the check valve upstream of FV-X01-29 passes.

10. Place FV-X01-29 (MEA to Absorber) in Manual at 10% open.

11. Open the suction valves to both MEA solution pumps and vent casing to fill with liquid.

MEA circulation can be started with either pump X01-J-503/504.

12. Ensure the discharge block valve is closed on X01-J-504.

13. Start the pump and slowly open the discharge valve to maintain 45 Barg discharge and 27,000-kg/hr flow through FV-X01-29.

14. As the pump pressure and flow stabilises, place FV-X01-29 in Auto and set at approximately 30,000 kg/hr. Set FV-X01-76 in Auto at 27,000 kg/hr.

15. Monitor the Regenerator level closely; due to the time, it takes MEA to circulate throughout the system. Make-up as necessary from the MEA sump and MEA storage tanks to establish system levels at 60%.

16. Closely monitor the MEA circulation pumps for abnormalities and check the entire system for leaks.

17. Sample the MEA solution concentration and adjust to 15% wt.

18. Establish flow through the Carbon and cartridge filtration system.

19. Continue "Cold" MEA circulation.



MEA-CO2 REMOVAL

4.0 NORMAL START-UP

4.1 HOT MEA Circulation

4.1.1 Prerequisites for Start-up

It is assumed that prior to start-up:

The MEA Absorber and Regenerator systems have been prepared and inventoried with MEA solution and are at normal operating levels as described in Section 3 of this manual.

All blinds have been removed or are in their normal positions.

The MEA Absorber is pressurised to normal operating pressure of 41 Barg, Natural gas.

The Regenerator column is under normal operating pressure, (0.7 Barg)

All Safety systems are operational and in service. Fire/Gas, Safety showers, and ESD systems.

All control and instrument devices are operational.

Process utilities systems, (steam, water, condensate, and air) are available from off sites.

Chemicals required for the system are available, (e.g. Anti-foam, corrosion inhibitor, Soda ash).

4.1.2 CO2 Absorber and MEA Flash drum

1. Start the wash section pumps, X01-J-510/511 and set FIC X01-205 at 10,000 kg/hr and LIC-X01-204 at 50%, both in Automatic.

2. Ensure XV-X01-202 is closed with the downstream block valve to the hot flare open.

3. Set PIC-X01-215 on Auto at 3.5 Barg to the fuel gas system.

4. Ensure LIC-X01-21 (inlet to the flash drum) is unblocked, set at 60% and in Automatic.

5. Establish cooling water flow to X01-E-501/504.

6. Ensure PV-X01-07 is unblocked, set at 0.7 Barg in Automatic.



MEA-CO2 REMOVAL

7. Unblock the outlet of the MEA flash drum and LV-X01-218, set at 60% in Automatic to the Regenerator column.

8. Ensure the level in the Regenerator column is 50%, with the Lean/Rich cooler valves unblocked and the coolers liquid filled.

4.1.3 Starting the MEA Solution pumps

1. Ensure both solution pumps are coupled and have the proper rotation.

2. Ensure the pump and motor lubrication levels are correct

3. Ensure the suction screens are installed on both MEA pumps.

4. Ensure the cooling water supply and return is in service to both pumps.

5. Set FV-X01-76 (MEA Recirculation) in Manual and closed. This is to prevent reverse gas flow to the regenerator from the Absorber in case the check valve upstream of FV-X01-29 passes.

6. Place FV-X01-29 (MEA to Absorber) in Manual at 10% open.

7. Open the suction valves to both MEA solution pumps and vent casing to fill with liquid.

MEA circulation can be started with either pump X01-J-503/504.

8. Ensure the discharge block valve is closed on X01-J-504.

9. Start the pump and slowly open the discharge valve to maintain 50 Barg discharge and 27,000-kg/hr flow through FV-X01-29. (Minimum flow for the pumps is 27,000-k/g/hr)

10. As the pump pressure and flow stabilises, place FV-X01-29 in Auto and set at approximately 30,000 kg/hr. Set FV-X01-76 in Auto at 27,000-kg/hr.


12. Closely monitor the MEA circulation pump for abnormalities and check the entire system for leaks.



MEA-CO2 REMOVAL

X01-J-503 Turbine driven MEA pump

It is necessary prior to placing a steam turbine in service to ensure the turbine has been heated slowly and the steam is free of water, which could cause damage to the turbine blading.

1. Ensure the proper lubrication levels in the oil system.

2. Ensure cooling water flow to the bearings and oil cooler

3. Place the steam trap downstream of the 4" block valve on the steam outlet of X01-J-503T in service.

4. Open fully all the drains on the turbine casing.

5. Open slightly the 4" steam outlet block valve to begin to warm up the turbine casing. Begin to close the drains as the steam becomes "dry"; open fully the outlet steam valve. Leave the drains open slightly until the turbine has been started to ensure there is no water present in the turbine casing and the casing remains hot.

6. Reset the "Trip and Throttle" valve on the Steam admission chamber.

7. Open the ¾" drain valve upstream of the block valve on the steam inlet line to drain and warm the steam inlet piping. Place the steam trap in service.

8. Ensure FV-X01-76 is in Manual and closed, to prevent potential reverse gas flow from the absorber to the Regenerator.

9. Open the discharge block valve on X01-J-503.

10. Place FV-X01-29 in Manual, set at 10%. (Minimum flow for the pumps is 27,000-k/g/hr)

11. Slowly open the steam inlet valve fully to X01-J-503T, allowing the Governor controller to maintain 3900 RPM.

12. As the pump pressure and flows stabilises, set FV-X01-29 on Auto at 30,000-k/g/hr.

13. Set FV-X01-76 on Auto at 27,000-kg/hr.




MEA-CO2 REMOVAL

15. Closely monitor the MEA circulation pump for abnormalities and check the entire system for leaks.

4.1.4 Establishing Hot Circulation

The MEA/CO2 Absorber and Regenerator will be in service with "COLD" circulation as described in the previous sections.

Lean MEA flow to the Absorber column at approximately 30,000-kg/hr, on Automatic control.

PIC-X01-215 at 3.5 Bar, in Automatic. LIC-X01-21 at 50% in Automatic. Wash water flow, FIC-X01-205 at 10,000-kg/hr with LIC-X01-204 at 50% in Automatic.

PIC-X01-04 (Natural gas Feed) set at 41 Barg in Automatic.

4" block valve on the Absorber overheads to Hot flare (Start-up) open slightly to establish a small gas flow through the absorber.

LIC-X01-26 (to Hydro-carbon decanter) in Automatic set at 40%.

MEA filtration system in service. (X01-P-501, X01-P-502A/B/C)

Amine purifier, X01-E-505 loaded with soda ash.

4.1.4.1 Commission Steam to X01-E-506 Gas pre-heater

1. Open the ¾" drain valve downstream of the 10" inlet block valve to X01-E-506. Place the steam trap in service.

2. Open slightly the bypass valve on the condensate outlet, LV-X00-125.

3. Slowly open the inlet steam valve to X01-E-506 to heat the exchanger. Close the bypass on LV-X00-125 and place LIC-X00-125 in Cascade with TIC-X00-125 set at 38° C. There will not be too large of an increase in temperature at this point due the small gas flow at this time.

4.1.4.2 Commission Steam to X01-E-502 Regenerator Reboiler

1. Open the Condensate outlet block valve downstream of the steam traps on X01-E 502.

2. Open both steam trap inlet block valves and strainer drain valves on the steam traps on X01-E-502. Leave the outlet block valves (2) closed.



MEA-CO2 REMOVAL

3. Open the ¾" drain and steam trap on the inlet steam upstream of FV-X00-78 (X01-E-502). FV-X00-78 in Manual and closed.

4. Open slowly the inlet steam block valve to warm up the steam piping. When free of water, close the ¾" drain. Open the main block valve fully.

5. Open FV-X00-78 slowly to 5%, as steam appears at the strainer drains. Close and open the steam trap outlet block valves fully.

6. Continue to open FV-X00-78 to raise the regenerator column overhead temperature to 100° C. Place in Automatic.

7. At this stage the level in X01-G-502, Acid Gas Separator will start to increase. Start the condensate pump (X01-J-506) and place LIC-X01-19 in Automatic at 50%.

4.1.4.3 Starting the MEA Purifier

Although corrosion inhibitor is added into the MEA Regenerator overhead system to neutralise the vapour containing CO2, other corrosion problems are often caused by poor maintenance of the amine solution.

The purpose of the MEA purifier, X01-E-505 is to remove any impurities caused by the oxidation and degradation of the amine solution, which could lead to corrosion problems within the system. These impurities are non-volatile and can be separated from the amine by distillation.

A small slipstream of amine is drawn from the bottom tray of the MEA regenerator column by level control, LIC-X01-01 on (X01-E-505) to maintain the liquid level above the tube bundle. The MEA solution is heated by 10.3 Barg, 212° C steam on the tube side of X01-E-505. Amine solution is admitted to the purifier at the same rate of the vapour boil-off. This vapour leaves the purifier and re-enters the MEA regenerator column under tray 21.

During the distillation process in the purifier, the acidic components in the MEA solution form salts with the sodium carbonate added to the purifier at the start of each cycle. The salts, together with other degradation products form sludge, which accumulates in the tube bundle of X01-E-505. They can be drained, or washed out by using steam condensate at the end of each purification cycle indicated by high temperature, +150° C on X01-E-505.

The MEA Purifier should be placed in service as soon as possible after establishing amine circulation.



MEA-CO2 REMOVAL

The operation of the MEA purifier is semi-continuous in that it operates for one cycle and then must be shutdown, cleaned and placed back in service.

1. Ensure that the purifier has been cleaned after the last purification cycle.

2. Close all block valves on the inlet and outlet of the purifier.

3. Add one bag (25-50 kg) of Soda ash via the 4" flange on the top of the purifier.

4. Place LIC-X01-01 in Manual closed and unblock the valves on LV-X01-01.

5. Open the outlet block valve on the purifier.

6. Start a small flow to the purifier through FI-X01-06.

7. Fill the purifier to approximately 55%. Close the globe valve on FI-X01-06.

8. Open slowly FV-X00-77 on the 10.3 Barg steam inlet to the purifier. Adjust the steam flow to reach the temperature of 110 °C on TI-X01-02 at a rate of 30 °C/hr (maximum).

9. When a temperature of 110 °C is reached, monitor closely the level in the purifier. As the level decreases, open the globe valve on FI-X01-06 and commission the level controller on LV-X01-01. Set at 55%.

10. Record the temperature and flow every 8 hours. If the temperature has remained steady, but the flow has decreased. Increase the temperature by steam flow FV-X00-77.

11. Repeat step 10 until the purifier temperature reaches 145 °C. At this point 3.45 Bar steam must be injected to reach the higher temperatures. Open the drain on the exchanger until all condensate is removed. Open the steam to the exchanger.

12. Close LV-X01-01 and FI-X01-06. When the level decreases below the sight glass, block in the steam. The purifier is at the end of its operating cycle.

13. Open the drain valves and drain the remaining liquid to the sewer.

14. Close the outlet block valve of the purifier.



MEA-CO2 REMOVAL

15. Open the flange on top of the purifier, wash the remaining sludge to the sewer.

16. Add more Soda ash, and the purifier is ready to begin another purification cycle.

4.1.4.4 Injecting Anti-foam Solution

Anti-foam solution injection at very low and variable rates is required to control foaming in the MEA Absorber and Regenerator. Foaming can be caused by:

Rapid changes in the flow rates of "Lean" MEA solution, or the Natural gas feed to the Absorber column.

Accumulation of impurities in the MEA solution throughout the system, such as hydrocarbons, dust, dirt, and MEA degradation products.

Excessive addition of corrosion inhibitor to the system.

Low temperature of "Lean" MEA to the absorption column.

Excessive addition of anti-foam chemical.

It is therefore very important that all flow; temperature and pressure changes in the MEA system are made slowly and gradually. The MEA filters and purifier should be placed in service as soon as possible after establishing MEA circulation.

Anti-foam is injected into either the "lean" or "rich" MEA solution at the following points:

The suction of the "lean" MEA solution pumps to control foaming in the Absorber.

Into the "rich" MEA solution at the outlet of X01-E-503A to control foaming in the Regenerator column.

Foaming is evident when the following deviations from normal operating conditions, (pressures, levels, flows, temperatures, and CO2

content are indicated in the MEA/ CO2 system.

An increase in the differential pressure across the absorber column trays as indicated on PDI-X01-28. If the pressure drop across the trays exceeds 140 mm Hg, foaming could be the cause.



MEA-CO2 REMOVAL

An increase in the differential pressure across the regenerator column trays as indicated on PDI-X01-09. If the pressure drop across the trays exceeds 160 mm Hg, foaming could be the cause.

A decrease of liquid level in the regenerator bottom. If the levels in the MEA absorber, flash drum, and the acid gas separator are normal, but the liquid level in the regenerator bottom decreases rapidly, foaming in the regenerator could be a possible cause.

Rapid decrease in the liquid level in the absorber, or large fluctuations of the absorber and regenerator levels. An increase in the level of the acid gas separator could be caused by foaming in the absorber or regeneration columns.

Liquid carryover from the absorber column overheads to the dryer separator. A sudden increase of the liquid level in the dryer separator, indicated on LAH-X02-01 and LSHH-X02-256 could be caused by foaming in the absorber column.

An increase in the CO2 content of the absorber overheads, with all other operating parameters at normal levels, could be an indication of foaming.

Anti-foam solution is injected at maximum 11 litres per hour, only when evidence of foaming appears. Continuous injection of anti-foam is not necessary and must be avoided as excessive injection can cause undesirable foam formation and further aggravate the foaming condition. The recommended anti-foam is an aqueous solution, Union Carbide UC-SAG-7133, or equivalent. It is assumed that the anti-foam injection system has been pre-commissioned and thoroughly cleaned prior to start-up.

1. Ensure the 1" drain line on the drum is closed. Fill the mixing drum to approximately 30% with condensate through the condensate make-up line. Add 30% level of anti-foam solution, start the agitator and thoroughly mix the solution.

2. Open the block valve at the suction of the injection pump. Open the ¾" strainer drain to fill the piping. Clean the strainer as necessary.

3. Open the isolation valves on PI-X01-210/235/236, with the pump discharge still closed start the pump and ensure PSV-X01-41 opens at 52.2 Barg (PI-X01-235) for pump protection. Vent the air from the pump and PI's to fill lines.

4. Open the first block valve at the pump discharge.

5. Open the block valve to either injection point:



MEA-CO2 REMOVAL

The suction of the "lean" MEA solution pump.

The outlet of X01-E-503A "rich" MEA.

6. Set the injection flow at 30% design and adjust as necessary.

7. Continue to increase and inject anti-foam until the differential pressure in the affected area returns to normal. Shutdown and isolate the pump.

4.2 Establishing Natural Gas feed through the CO2 Absorber

MEA is circulating through the system at normal temperatures, flows and pressures. The dehydration and cryogenic sections are available for service.

1. Set lean MEA flow at 40,000-kg/hr.

2. With PIC-X01-04 in Automatic, set at 41 Barg slowly. PV-X01-04 will control to admit gas to the absorber column.

3. Ensure the feed gas knockout section LV-X01-26 is in service to the Hydrocarbon decanter. LIC-X01-26 set at 20% in Automatic.

4. Open slightly the 4" globe valve on the CO2 absorber overheads to the Hot flare, (Start-up line).Set flow at 65,000 Nm3/hr, indicated on FT-X01-05.

5. Allow the system to stabilise.

6. Place AT-X01-38 (overhead CO2 analyser) in service.

7. Open the 1" bypass valve on the 20" absorber overheads line to the Dehydration section. Pressurise the entire system downstream to normal operating pressure. Open the 20" overhead block valve.

8. Set TIC-X01-25 on the feed gas preheater at 38 °C in Automatic.

9. Monitor the temperatures, pressures and flows throughout the system.

10. Ensure the reboiler on the MEA Regenerator is at 118 °C with FIC-X01-78 in Automatic.

11. Ensure PIC-X01-07 is set at 0.7 Barg in Automatic.

12. The MEA solution heat balance will change as acid gas is extracted from the system. Allow the system to stabilise before increasing the feed gas flow.



MEA-CO2 REMOVAL

13. Adjust feed gas flow to 65,000 Nm3/hr. The system can remain in this state until feed is increased to the cryogenic section utilising TIC-X01-12.

Feed gas increases should always be made in small increments and will involve changes in the MEA circulation rates. Allow the process to stabilise before proceeding with an increase in feed gas flow. For efficient CO2 absorption, it is essential that the operating variables be maintained in a steady state.

5.0 NORMAL OPERATION

5.1 Normal Operating Parameters

Typical operating parameters for the MEA/CO2 Removal System are listed below and these mainly depend on the feed gas flow rate and composition.

Refer to the Process Flow Diagram 85-X01-PF-10A.



MEA-CO2 REMOVAL

All data listed below is based on 100% design capacity.

Stream Temperature, oC Pressure, bargL.F.C H.F.C L.F.C H.F.C

Feed to the Inlet Separator

Downstream X01-E-506

Absorber overheads

Amb

38

38

Amb

38

38

41.2

41.2

41

41.2

41.2

41

Flow Rates

Unit L.F.C. H.F.C

Gas Feed to the Inlet Separator (per hr)

Absorber Column Overhead

Lean MEA to Absorber

Demin water to Wash section

103Nm3

103Nm3

Kg/h

Kg/h

253.4

253.4

61,000

53,400

243.4

243.4

51,000

53,400

During normal operations, the above parameters are most likely to be at some points between the two possible cases shown above.

Notes:

L.F.C.: Light Feed Gas CaseH.F.C.: Heavy Feed Gas Case



MEA-CO2 REMOVAL

5.2 Feed Stream Composition

The feed entering the Absorber Column is withdrawn from the Complex feed gas header and its composition depends on whether the feed gas to the train is lean or rich. However, during normal operations, the feed gas composition is most likely to be at some point between the two possible feed gas cases shown below.

Components Formula L.F.C. H.F.C.

Mole % Mole %

Nitrogen

Helium

Methane

Ethane

Propane

Iso-Butane

Normal Butane

Iso-Pentane

Normal Pentane

Hexanes and Heavier

Carbon Dioxide

Water (ppm)

N2

He

CH4

C2H6

C3H8

iC4H10

nC4H10

iC5H12

nC5H12

C6+

CO2

H2O

6.0

0.21

84.6

6.77

1.48

0.20

0.30

0.07

0.07

0.00

0.30

50

3.32

0.11

84.91

7.90

2.15

0.40

0.50

0.16

0.17

0.20

0.18

50

Total 100.00 100.00



MEA-CO2 REMOVAL

5.3 Product Stream Composition

The Absorber column overhead stream varies very slightly from the inlet stream to the Absorber column, with the exception of the concentration of carbon dioxide (CO2), which is considerably less than the inlet stream.

During normal operations, the composition is most likely to be at the some point between the two possible compositions shown below:

Components Formula L.F.C. H.F.C.Mole % Mole %

Nitrogen

Helium

Methane

Ethane

Propane

Iso-Butane

Normal Butane

Iso-Pentane

Normal Pentane

Hexanes and Heavier

Carbon Dioxide

Water

N2

He

CH4

C2H6

C3H8

iC4H10

nC4H10

iC5H12

nC5H12

C6+

CO2

H2O

6.01

0.21

84.71

6.78

1.48

0.20

0.30

0.00

0.00

0.00

<90ppm

0.16

3.32

0.11

84.93

7.90

2.15

0.40

0.50

0.16

0.17

0.20

<90ppm

0.16

Total 100.00 100.00



MEA-CO2 REMOVAL

6.0 OPERATING VARIABLES

The main function of the MEA/CO2 Removal Section is to maintain the quality of the products leaving this section. This is normally accomplished by the automatic controls described in Chapter No. 7.

1. Observable Variables: Pressure, Temperature, Level, Flow, and Stream Composition.

2. Internal Variables to this Section: These variables are dependent on special or alternate modes of operation within the system and which can be controlled, e.g. Feed gas flow and MEA Flow Rates and temperatures.

3. External Variables to this Section: These variables are beyond control, e.g. Feed Gas Composition, Ambient Temperature, etc.



MEA-CO2 REMOVAL

6.1 Internal Variables

6.1.1 CO2 Absorber Overhead Product

For effective CO2 absorption, it is essential to keep the process variables on the absorber column at the most efficient values.

Feed gas inlet temperature, controlled by TIC-X01-25 on X01-E-506, set at 38° C.

Lean MEA flow to the Absorber, controlled by FIC-X01-29 on tray 3. Normal flow 54,700 kg/hr.

Lean MEA solution temperature to the absorber, set with the manual bypass around X01-E-504 at approximately 2-5° C above the gas temperature.

Lean MEA strength 15-20%, controlled by regenerator operation and system make-up.

6.1.2 MEA Regenerator

The ability of CO2 absorption in the absorber column is largely affected by the operation of the MEA regenerator column. That is to say, if the regenerator is not operating properly the optimal strength of the lean MEA solution will be at a lower value affecting the ability to absorb CO2.

Regenerator column pressure, maintains the column at a low pressure to distill the CO2 from the amine solution. Set at 0.7 Barg on PIC-X01-07.

Regenerator column reboiler temperature operates in conjunction with the column pressure. Maintains the column temperature necessary to boil the CO2 from the amine solution. Set at 118° C by FIC-X00-78.

The amine purifier, filtration, corrosion protection, make-up, and anti-foam systems also play an important role in maintaining the MEA solution integrity.

6.2 External Variables

6.2.1 Site Temperature

Site temperature variations have no major effect on the operation of this system.



MEA-CO2 REMOVAL

6.2.2 Feed Gas Composition

The light feed gas case and the heavy feed gas case compositions result in changes in the composition of the feed gas. The principal change, which will affect this system, is the concentration of CO2 in the feed gas. Changes in the feed gas flow cause the distribution of the MEA solution to change and may require adjustments to the Lean MEA flow rate and steam flow to the Reboiler X01-E-502.

7.0 PROCESS CONTROL

7.1 Natural Gas Feed

Natural gas enters the GL1Z complex via a 42" collection header equipped with an ESD valve JV-000-00 at the complex boundary. The pipeline pressure can range between 42-49 Barg with a temperature between 0° C - 25° C. Pipeline pressure and temperature are indicated by PIT-000-07 and TI-000-05 respectively in the offsite control room. Analyser AT-940-38 collects a sample of the gas stream and transmits a Density correction signal to FT-X01-05 (feed gas inlet to trains) for flow calculation purposes.

Natural gas enters the individual trains through a 20" line equipped with an ESD valve JV-X01-70 and a pressure control valve PV-X01-04. PIC-X01-04 controls the inlet feed gas pressure at 41.2 Barg. Flow is measured by an orifice meter FI-X01-05 and transmitted to the DCS control room prior to the gas entering the disengaging section in the bottom of the MEA absorber column.

The normal liquid level in this section is 10-15% maintained by LIC-X01-26, which sends any liquids to the hydrocarbon decanter. During normal operation, this level should be monitored closely to avoid sending hydrocarbon liquids to the bottom of the MEA absorber. A high level alarm LAHH-X01-224 is provided in the DCS control room. There normally is very little liquid flow from this bottom section.

The feed gas leaves this section and flows through feed gas pre-heater X01-E-506 where it is heated to 38° C utilising 3.45 Barg steam on the shell side. This temperature is regulated by TIC-X01-25 set at 38° C, which overrides the level controller, LIC-X00-125 on the condensate outlet line. TIC-X01-25 has an associated high alarm, TAH-X01-25 set at 42° C, and TAL-X01-25 set at 33° C.

To control the water balance in the MEA absorber and saturate the feed gas before it enters the column, 62 Barg steam is injected via a manual controlled globe valve into the outlet of X01-E-506.



MEA-CO2 REMOVAL

7.2 Absorber Contacting Section

The lean MEA is supplied to the absorber column on tray 3 and descends through the valve trays, where the CO2 in the raw feed gas rising through the column is absorbed by the MEA solution. The resultant gas passes overhead through the wash section prior to entering the dehydration section.

The wash section consists of the last 2 trays in the absorber, a chimney tray and a demister pad near the top outlet of the column. The feed gas leaving the contacting section enters the wash section via the chimney tray. Any MEA solution carried upwards is washed down with demineralised water to be collected in the chimney tray.

Wash water level on the chimney tray is controlled by LIC-X01-204 acting upon LV-X01-204 routing excess water to the MEA flash drum (normal), or the hydrocarbon decanter. Normal set point is 30%. Water makeup to the system is provided from the utilities unit manually controlling the flow on FI-X01-206 with the needle valve provided. An emergency valve XV-X01-223 is also provided and connected to the Process Shutdown system. XV-X01-223 acts as follows:

Closes on LAHH-X01-229 MEA Flash drum High high level. Valve position indicators ZLO/ZLC-X01-223 are indicated on the

DCS in the CCR.

Two wash water pumps X01-J-510/511 are provided for circulation back to tray 1. Suction of the pumps comes from the chimney tray. Water flow is controlled by FIC-X01-205 set at 53,800 kg/hr (normal). High and low flow alarms are provided on the DCS. Each pump has "motor running" (JI-X01-228/229) indicated on the DCS.

X01-J-510/511 are connected to the Emergency Shutdown system and operate as follows:

Via HS-X01-227A at the LCR (Process train shutdown system) Via HS-X01-227B at the CCR (Process train shutdown system) Via XS-X00-279 (Fire and Gas Detection system)



MEA-CO2 REMOVAL

Pump Characteristics

Wash Water pumps X01-J-510/511Type Centrifugal, single stageManufacturer GouldsDesign Discharge pressure 45.5 BarOperating Discharge pressure 44.5 BarFluid Operating temperature 38° CDesign Flow 64.6 m3/hrNormal flow (110% of design) 53,800 kg/hrMinimum Continuous flow 22 m3/hrPump speed 1480 RPMMotor power 10 HPCurrent 380V AC 3 Phase 50 Hz

Before leaving the wash water section the overhead gas stream passes through a demister pad where moisture particles are collected and returned to the column. The following valves and instrument are provided on the overhead vapour line of the absorber column.

10" depressuring line to Hot flare system that is used for Emergency depressuring. This line is equipped with:

o 10" (locked open) manual block valveo 3" pneumatically operated valve (XV-X01-202) connected

to the Process Shutdown and Emergency depressuring system operating as follows:

o XV-X01-202 can be "Opened or Closed" via HS-X01-202 in the CCR. (Process Shutdown system)

o XV-X01-202 will "Open" Via HS-X01-1230A in the LCR Via HS-X01-1230B in the CCR

(Emergency Depressuring system)The valve will open only after the permissive signal (ZSC-X02-252) has been received, indicating valve XV-X02-252A downstream of the demercuriser is closed.

8" line to the Hot flare with a 4" globe valve for start-up purposes.

20" manual isolation valve from the downstream system.

Gas temperature and pressure are approximately 38° C and 41 Barg, indicated on TI-X01-101and PIT-X01-37 respectively on the DCS. The column is protected from overpressure by PSV-X01-30, set at 49.7 Barg relieving to atmosphere. The residual CO2 content of the gas, less than 20 ppm is continuously analysed by AE-X01-38 and indicated in the CCR, with a high alarm AAH-X01-38 set at 90 ppm.

A pressure differential indicator PDI-X01-28A is used to measure the pressure drop across the column trays, which indicates tray "loading" or



MEA-CO2 REMOVAL

"foaming". This transmitter can be also utilised to indicate differential pressure across partial absorber sections dependant upon the transmitter valve alignment. High differential pressure alarm PDAH-X01-28A is set 140 mmHg and indicated in the CCR.

The CO2 rich MEA solution is collected in the sump section of the absorber column. The level in the absorber is controlled by LIC-X01-21 in the DCS, which actuates LV-X01-21 on the outlet line to the MEA Flash Drum. Normal level set point in the absorber bottoms is 60%. A low low level alarm LALL-X01-225 is indicated on the DCS in the CCR.

LALL-X01-225 is connected to the Process Shutdown system and initiates the following actions:

Closes XV-X01-212 Absorber bottom outlet valve.

Valve position indicators ZLO/ZLC-X01-212 on XV-X01-212 are indicated on the DCS in the CCR.

7.3 MEA Circulation and Regeneration

7.3.1 MEA Flash Drum

The CO2 rich amine solution exits the absorber bottom and enters the MEA flash drum. Across LV-X01-21, the pressure is reduced from 41 Bar to 8 Bar. This causes the hydrocarbons in the solution to flash and create a vapour space in the drum, which is used to control the liquid level. Pressure is controlled by PIC-X01-215, which actuates PV-X01-215 set at 8 Bar. The gas is routed to the fuel gas system. High-pressure alarm PAH-X01-215 set at 10 Bar, and low-pressure alarm PAL-X01-215 set at 6 Bar are also provided on the flash drum.

PV-X01-215 is connected to the Process and Emergency shutdown systems and operates as follows:

PV-X01-215 will CLOSE: Via LAHH-X01-215 (Process Shutdown System) Via HS-X01-227A in the LCR (Process Shutdown System) Via HS-X01-227B in the CCR (Process Shutdown System) Via HS-X00-279 (Process Train Fire and Gas Detection system)

The MEA flash drum is protected from over pressure by PSV-X01-217 set at 12 Bar relieving to the atmosphere. The level in the flash drum is controlled by LIC-X01-218 actuating LV-X01-218 in the outlet line to the MEA exchangers X01-E-503A/B. Normal operating level is 40%. High-level alarm LAHH-X01-219 and low-level alarm LALL-X01-220 are provided and displayed on the DCS.



MEA-CO2 REMOVAL

LAHH-X01-219 and LALL-X01-220 are connected to the Process Shutdown system and initiate the following actions on a high or low level in the drum.

LAHH-X01-219 will CLOSE: XV-X01-212 (MEA Absorber bottoms) XV-X01-215 (Flash Drum overhead) XV-X01-223 (MEA wash water make-up)

LALL-X01-220 will CLOSE: LV-X01-218 (MEA Flash drum bottoms)

7.3.2 Regenerator Column

The rich MEA leaves the Flash drum and flows through the tube side of X01-E-503B/A respectively prior to entering the regenerator column. TI-X01-114 on the tube side inlet of X01-E-503B is displayed on the DCS with associated high alarm TAH-X01-114 set at 47° C and a low alarm TAL-X01-114 set at 32° C. TI-X01-017 on the tube side inlet of X01-E-503A allows for local temperature indication. TI-X01-115 on the tube side outlet of X01-E-503A in the DCS is utilised to assess the heat transfer across both exchangers. High alarm TAH-X01-115 set at 100° C and low alarm TAL-X01-115 set at 82° C are also provided.

The rich MEA solution enters the regenerator on tray 1 through LV-X01-218, which receives the output signal from LIC-X01-218. Across the valve, the pressure is reduced from 8 Bar to 0.7 Bar. At this pressure, most of the CO2 flashes along with traces of MEA and water vapour and are carried overhead. A demister pad collects most of the water vapour overhead and returns it to the column. The CO2 gas and some water vapour carry overhead into the condenser X01-E-501 at approximately 107° C indicated on TI-X01-106 in the DCS, where it is cooled to approximately 52° C. A temperature indicator, TI-X01-107 and high alarm TAH-X01-107 set at 57° C are provided on the outlet line.

The seawater flow on the tube side of this exchanger is manually controlled with a ball valve installed on the supply piping to the exchanger.

Pressure control of the column is achieved by PIC-X01-07 (DCS controller) receiving a signal from PI-X01-07 which is located upstream of X01-E-501. The PIC sends a signal to PV-X01-07 located on the acid gas separator. Any non-condensable gases are vented to atmosphere. A sample connection located upstream of PV-X01-07 is provided for periodic monitoring of the gas effluent.

Condensate level collected in the acid gas separator is controlled on the DCS by LIC-X01-19, which actuates LV-X01-19 to return the fluid with



MEA-CO2 REMOVAL

pump X01-J-506 to the MEA regenerator column. Normal operating level is set at 50%. Condensate can be routed to either the sump of the regenerator column, or the reboiler inlet line.

Condensate pump X01-J-506 is connected to the Process and Emergency Shutdown system and will operate as follows during an emergency:

X01-J-506 will STOP: Via LALL-X01-226 Separator level (Process Shutdown system) Via HS-X01-226A at the LCR (Process Train Shutdown system) Via HS-X01-226B at the CCR (Process Train Shutdown system) Via HS-X00-279 (Train Fire and Gas Detection System)

The set point of LALL-X01-226 must be synchronised with the input signal of LV-X01-19 so the pump stops before the valve is fully closed to protect the pump from low flow conditions.

The remaining traces of CO2 in the MEA flow down the column and are removed by the hot stripping vapour travelling up through the column. The following indications are provided for the operation of the regenerator column:

PI-X01-108 local pressure indicator, Tray 21 vapour TI-X01-12 local temperature indicator, Tray 21 PDI-X01-09 local differential pressure indicator can be valved to

provide total column differential pressure, or individual section differential pressure.

The regenerator column is protected from overpressure by PSV-X01-14, set at 5.17 Bar

The stripping steam is produced in the MEA reboiler by vaporizing a part of the MEA solution entering the reboiler after collection on tray 21.The liquid flows into the shell side of the reboiler and is heated by 3.45 Barg 150° C steam. An overflow weir ensures the tube bundle is completely covered with MEA solution at all times, for maximum efficiency and protection against overheating. Thermo-syphon effect is used to direct the vaporized portion of the MEA solution back to the Regenerator column under tray 21. The non-vaporized portion of the MEA solution overflows the weir into the bottom of the regenerator column.

The 3.45 Bar saturated steam through the reboiler tubes is controlled by FIC-X00-78 from the CCR by actuating FV-X00-78 on the steam inlet to the reboiler. Flow is set at 5600 kg/hr or as necessary to maintain the temperature on TI-X01-108 at 118° C. TI-X01-108 and TAL-X01-108 set at 110° C are indicated on the DCS. The condensate returns to the condensate header.



MEA-CO2 REMOVAL

FV-X00-78 is connected to the Emergency Shutdown system and operates as follows:

FV-X00-78 will CLOSE: Via HS-X01-227A at the LCR (Process Train Shutdown system) Via HS-X01-227B at the CCR (Process Train Shutdown system) Via HS-X00-279 (Train Fire and Gas Detection System)

The MEA sump section is located in the bottom of the MEA regenerator. A low-low level LALL-X01-13 and high level alarm LI-X01-13 are provided as well as temperature on TI-X01-108 with a low temperature alarm TAL-X01-108 set at 110° C. LALL-X01-13 is connected to the Process Shutdown system and initiates the following actions:

Closes FV-X01-29 MEA to the Absorber column. Opens FV-X01-76 MEA solution pump minimum flow.

A local flow indicator FI-X01-10 is provided on the condensate make-up to the bottom of the regenerator. It is expected that normal make-up rates will be approximately 48 kg/hr.

7.3.3 MEA Solution Pumps X01-J-503/504

The lean amine solution exits the bottom of the regenerator column at approximately 116° C where it is cooled to 71° C in X01-E-503A/B shell side with the rich amine solution flowing through the tube side.

The following instruments are associated with the solution exchangers. Local temperature indicator, TI-X01-16 on the shell side outlet of X01-E-503A. Temperature indicator TI-X01-109 on the shell side outlet of X01-E-503B, with associated high TAH-X01-109 set at 78° C and low TAL-X01-109 set at 62° C alarms on the DCS.

A local pressure indicator PI-X01-18 on the shell side outlet of X01-E-503B, which provides suction pressure indication for the MEA solution pumps. A corrosion probe on X01-E-503A shell side inlet for corrosion monitoring.

The function of the MEA solution pumps X01-J-503/504 is to return the Lean MEA solution to tray # 3 of the Absorber column. In order to do this the pump must increase the pressure from 0.5 Bar to 52 Bar to overcome the Absorber pressure (41 Bar), and friction losses in the piping.

Two solution pumps are provided, one driven by a steam turbine (X01-J-503T) at 16.2 Bar and 221° C superheated steam. The other (X01-J-504) driven by an electric motor (380 Volt AC). Normally the turbine driver is in service with the electric driven pump in Auto/standby. PAL-X01-62 (low pump discharge pressure) on X01-J-503 will automatically start the



MEA-CO2 REMOVAL

standby electric pump (X01-J-504) at 35 Bar (decreasing) pressure to maintain MEA flow to the absorber column.

The electric pump X01-J-504 is connected to the Process and Emergency Shutdown system and will operate as follows:

X01-J-504 will STOP: by the Process Shutdown system and indicating X01-J-503 is not

running on PAL-X01-65 (discharge pressure). By HS-X01-227A at the LCR (Process Train Shutdown system) By HS-X01-227B at the CCR (Process Train Shutdown system) By HS-X00-279 (Train Fire and Gas Detection System) Electric Power failure by XS-X00-284

The lean MEA pumps send the MEA to the solution cooler X01-E-504 where it is further cooled from 71° C to 40° C. A bypass line is provided on the cooler to maintain temperature during periods of cold weather. A temperature indicator TI-X01-103 (DCS) with high alarm TAH-X01-103 set at 42° C and a local indicator TI-X01-32 are provided on the shell side outlet for monitoring purposes.

Downstream of X01-E-504 a flow control valve FV-X01-76 is provided for minimum flow protection of the solution pumps. This valve recycles MEA back to the pump suction, receiving a signal from FIC-X01-76. Normal set point is 27,000 kg/hr. Minimum flow control is required during pump start-up and shutdown operations

FV-X01-76 is connected to the Process Shutdown system and operates as follows:

FV-X01-76 will OPEN and FV-X01-29 will CLOSE simultaneously by LALL-X01-13, Regenerator bottoms low low level.

The main MEA flow is directed to tray #3 in the absorber column by FV-X01-29, which receives a signal from FIC-X01-29 on the DCS. The normal MEA flow is approximately 61,000-kg/hr dependent upon unit load conditions.

Flow valve FV-X01-29 is connected to the Process Shutdown system and operates as follows:

FV-X01-29 will CLOSE: By LALL-X01-13, Regenerator low low level. (Process Train

Shutdown system) By HS-X01-227A at the LCR (Process Train Shutdown system) By HS-X01-227B at the CCR (Process Train Shutdown system) By HS-X00-279 (Train Fire and Gas Detection System)



MEA-CO2 REMOVAL

7.3.4 MEA Filtration

A slipstream of MEA, approximately 4% of the total flow to the MEA absorber is taken off upstream of FV-X01-29. The flow is manually set by FI-X01-33. It passes through cartridge filter (X01-P-502A) to remove any solid particles greater then 5 micron. The solution then passes through a bed of activated carbon, (X01-P-501) which removes any compounds that could cause foaming in the MEA columns. It is then passed through another cartridge filter (X01-P-502B) to remove any carbon particulate and rejoins the lean MEA stream downstream of FV-X01-29 on the inlet of the MEA absorption column.

The normal pressure drop across each of the 3 filters is 0.5-0.7 Bar. Cartridge filter change is required at 1-1.4 Bar. When the differential pressure across the carbon filter is greater then 1.4 Bar, the bed must be replaced. Local pressure indications, PI-X01-76/47 are provided for differential pressure monitoring.

Another slipstream of lean MEA, (approximately 10% of total flow) is drawn off upstream of FV-X01-29 and passes through cartridge filter (X01-P502C) before returning downstream of FV-X01-29. The flow is adjusted manually through local flow meter FI-X01-34. The normal pressure drop across this filter is 0.5-0.7 Bar indicated locally on PI-X01-74. The filter element must be replaced at 1.4 Bar.

7.3.5 MEA Purification

A slipstream of MEA solution is drawn from the chimney tray of the regenerator to the MEA purifier. (MEA can also be pumped from the MEA sump to the purifier by restriction orifice RO-X01-67).

Local level controller LC-X01-01 maintains the level by acting on LV-X01-01 in the purifier inlet line, situated above the tube bundle. The normal flow to the purifier is 1527 kg/hr indicated by local flow indicator FI-X01-06. The MEA is heated by 10.3 Bar saturated steam on the tube side of the exchanger. Steam flow is regulated by DCS controller FIC-X00-77 actuating FV-X00-77 on the steam inlet line. Purifier temperature indication is provided locally by TI-X01-02

A 1½" superheated steam sparger line is provided for additional heat when the saturated steam will no longer supply the required heating value. As the level controller LC-X01-01 maintains level in the purifier, the rate of amine added is identical to the rate of vaporisation. The rate of vaporisation and the rate of solution added are determined by the amount of steam flow, (normally about 1750 kg/hr). As the solution in the purifier boils, the concentration of MEA in it increases until a portion is vaporised into the overhead line. Finally, equilibrium develops between the MEA



MEA-CO2 REMOVAL

concentration in the vapour returning to the regenerator and the solution added to the purifier.

As the process continues, the compounds formed by the chemical reactions between the soda ash and acid settle in the tube bundle and cause the temperature of the MEA solution to increase above the normal vaporisation point. At this time, (145° the purifier must be placed out of service and cleaned.

Flow valve FV-X00-77 is connected to the Process Shutdown system and operates as follows:

FV-X00-77 will CLOSE: By HS-X01-227A at the LCR (Process Train Shutdown system) By HS-X01-227B at the CCR (Process Train Shutdown system) By HS-X00-279 (Train Fire and Gas Detection System)

7.3.6 Chemical Injection

Corrosion inhibitor is injected into the overhead line of the Regenerator column through a 1" line. The corrosion inhibitor system consists of:

A mixing drum with a capacity of 380 litres. Electric agitator Local level indicator, LG-X01-247 A condensate make-up supply Metering pump X01-R-503J with a rated capacity of 19litres/hour Local pressure indicator PI-X01-233 (pump suction) Local pressure indicator PI-X01-201 (pump discharge)

The pump is protected from overpressure by PSV-X01-200 set at 7.3 Bar, which relieves back into the mixing drum.

X01-R-503J is connected to the Process Shutdown system and operates as follows:

X01-R-503J will STOP: By HS-X01-227A at the LCR (Process Train Shutdown system) By HS-X01-227B at the CCR (Process Train Shutdown system) By HS-X00-279 (Train Fire and Gas Detection System)

7.3.7 MEA Storage

7.3.7.1 MEA Sump X01-G-504

The MEA sump tank is a multi-purpose, non-pressurised underground vessel used for the preparation, reclamation, and transfer of MEA solution. It is connected with the MEA storage tank by a 6" underground line used for MEA transfer from the storage tank to the sump. Connected



MEA-CO2 REMOVAL

with the MEA system by a network of drain lines used for MEA reclaiming. A 1½" condensate line is connected to the sump for make-up water purposes.

The sump is also equipped with:

Pump X01-J-505 An MEA fill line A 2" vent to atmosphere A cover plate for inspection and observation Local pressure indication PI-X01-46

The sump can be used for the following:

To prepare 15-20 wt% MEA solution from concentrated MEA barrels for make-up into the system.

To prepare 20 wt% MEA solution for storage into the storage tanks.

To reclaim MEA from equipment that has been drained and transfer to the storage tanks.

To transfer MEA to different locations throughout the system.

7.3.7.2 MEA Sump pump X01-J-505

X01-J-505 is a vertical submerged centrifugal pump with a rated capacity of 5.68 m3/hr at a discharge pressure of 2.15 Bar. A local pressure indicator PI-X01-46, check valve and manual isolation valve are provided on the pump discharge.

The pump can be Start/Stopped by the local hand switch.

In the AUTO position the pump will be started by level switch LAH-X01-45 and stopped by level switch LAL-X01-45.

The pump is connected to the Process Shutdown system and operates as follows:

By HS-X01-227A at the LCR (Process Train Shutdown system) By HS-X01-227B at the CCR (Process Train Shutdown system) By HS-X00-279 (Train Fire and Gas Detection System)

7.3.7.3 MEA Storage Tanks 201-G-501/401-G-505

Two storage tanks are provided to supply MEA solution to the 6 LNG trains. Tank 201-G-501 situated in Train 200 supplies Trains 100/200/300. Tank 401-G-505 situated in Train 400 supplies Trains 400/500/600. Each storage tank is identical and has a capacity of 65 m 3 of 20 wt% MEA, which is sufficient to supply 3 process units. Each unit requires approximately 32 m3 of 15-20 wt% MEA for normal operation.



MEA-CO2 REMOVAL

Both tanks are equipped with a nitrogen blanketing system to prevent oxidation of the MEA solution by contact with the air consisting of:

1½" nitrogen supply piping to the tank.

Pressure control valve PCV 201-49/ PCV-401-55 set at 10 mbar.

Local pressure indicators PI-201-50/401-55.

A manual isolation valve and check valve.

The tanks are also provided with heating coils to prevent the MEA solution from freezing at high concentrations. The heating coils consist of:

1½" 3.5 bar saturated steam line with a manual globe valve.

A 1" condensate return line with a trap and check valve.

A ¾" bypass line between the steam and condensate for when the coil is out of service.

Additionally the tanks are equipped with the following instrumentation:

Local temperature indicators TI-201-53/401-59.

Local level indicators LI-201-54/401-59.

A 3" drain to the sewer system.

The storage tanks are protected from over-pressure vacuum by a 10" pressure/vacuum relief valve PSE 201-52/401-58 set at + 35 mbar and – 20 mbar respectively.

An interconnecting above ground/underground piping network between the tanks and the process units allows the transfer of MEA to/from the tanks.

From the MEA storage tanks, 201-G-501/401-G-505 to the MEA sump tank in the trains via 6" MEA-0101/0104.

From the MEA storage tanks, 201-G-501/401-G-505 to the MEA electric solution pumps in the trains via start-up line 6" MEA-X0103

From the MEA sump tank in the trains, to storage tanks 201-G-501/401-G-505 via the MEA sump pump.



MEA-CO2 REMOVAL

8.0 NORMAL SHUTDOWN

8.1 Stopping Feed Gas Flow

Normal shutdown will be performed only after the feed forward to the Liquefaction Main exchanger has been stopped. Normal shutdown assumes the shutdown is voluntary and controlled.

Normally the Gas purification, Dehydration and Liquefaction sections will be shutdown together, however if only a short-term shutdown of the liquefaction unit is necessary feed gas can be maintained through the MEA/CO2 removal section.

It will be necessary to maintain the Pre-treatment area in service until Deriming operations in the Liquefaction area are completed.

1. Reduce the rate of feed gas into the Liquefaction section as per procedure described in Section 6 of the Operating Manuals.

2. Reduce feed gas flow to approximately 110,000 Nm3/hr flow slowly to avoid upsets to the MEA system, the process unit and the utilities systems.

3. As feed gas is being reduced, slowly lower the set point on FIC-X0129 to 45,000 kg/hr. (Maintain column overheads CO2

specification at < 90 ppm).

4. Close XV-X02-252 (Demercuriser outlet filter) via HS-X02-252.

5. Ensure one drier is regenerated and available for service, regenerate the other drier as soon as possible.

6. Maintain a flow of 22,000 m3/hr through the absorber system for regeneration of the Driers.

7. When Drier regeneration and derime operations are complete, close the 20" Absorber overhead block valve to the Dehydration section.

8. Isolate the steam to X01-E-506 Preheater.

9. Place PV-X01-04 in manual and close.

10. Reduce the Lean MEA flow to 30,000 kg/hr on FIC-X01-29.

11. Maintain the pressure on the absorber column at 41 bar. It may be necessary to open the bypass around PV-X01-04.

12. Continue to circulate MEA solution until completely regenerated. (Verify with Laboratory analysis.)



MEA-CO2 REMOVAL

If the MEA solution is to be transferred to the Storage tanks, it may be necessary to continue to regenerate the MEA solution to 20% by boiling off the water content.

13. Shutdown the Anti-foam injection system.

8.2 Shutdown the MEA Purifier

1. Place LIC-X01-01 on manual and close.

2. Boil off remaining MEA in X01-E-505.

3. When the temperature on X01-E-505 rises above 140° C, open the manual steam sparger and boil the remaining MEA.

4. Place FIC-X00-77 in manual and close. Drain the residue in the exchanger to barrels and flush with water.

5. Isolate the condensate outlet.

8.3 Shutdown the MEA Regenerator

During the cool down of the regeneration system, closely monitor the system pressure to prevent a vacuum condition. Add nitrogen if necessary.

1. When the regeneration of the MEA solution is complete, begin the cool down of the regenerator and solution.

2. Place FIC-X00-78 (Reboiler steam) in manual and slowly close.

3. When a low level is reached in the acid gas separator, shutdown the condensate pump.

4. Place PIC-X01-07 in manual at 100% open.

5. Close the cooling water to the Regenerator overhead condenser.

6. When the temperature reaches 40° C on TI-X01-108 (Regenerator column bottom), stop MEA circulation by slowly closing FIC-X01-29. FIC-X01-76 will open automatically at 27,000 kg/hr.

7. Shutdown the MEA circulation pumps.

8. Isolate FV-X01-29 and LV-X01-21.

9. Close PV-X01-07 and connect a nitrogen hose to the regeneration column. Pressurise to 1.0 bar.



MEA-CO2 REMOVAL

8.4 Draining the Absorber and Regenerator system

If the system is to be shutdown for a short period and the columns are not to be entered for inspection, leave the MEA solution in the system. Depressure the Absorber and amine flash drum to 1 bar. Leave the Regenerator column under 0.5 Bar nitrogen pressure. If the systems are to be entered, drain the MEA to storage, purge the system with Nitrogen and steam out the columns.

8.4.1 Draining the MEA Regenerator to Storage

1. Open the 2" drain on the bottom of the regenerator column to the MEA sump.

2. Open the 1" drain on the regenerator reboiler (X01-E-502) bottom to the MEA sump.

3. Open the 1"drain on the shell side of X01-E-503B to the MEA sump.

4. Start the sump X01-J-505 and pump the MEA back to the storage tanks.

5. Pump out the sump and completely empty the regenerator system.

6. When the regenerator system is completely empty, close the drains.

7. Open the 1" bypass on PSV-X01-14, and PV-X01-07 to 100%.

8. Connect a steam hose to the steam out connection on the bottom of the regenerator column.

9. Steam out the column for minimum 24 hours.

8.4.2 Draining the CO2 Absorber to Storage

1. Depressure the Absorber column to flare.

2. Isolate LV-X01-26 to the hydrocarbon decanter.

3. Open the 1" drains on the tube side of X01-E-503A/B to the MEA sump.

4. Open the 2" bypass on LV-X01-21 completely. This will drain the absorber, to the MEA flash drum through the X01-E-503A/B drains.

5. Start X01-J-505 sump pump and transfer the MEA back to the storage tanks. Completely empty the system.



MEA-CO2 REMOVAL

6. Connect a nitrogen hose to the connection on the bottom of the Absorber column.

7. Purge the absorber system to flare.

8. Connect a steam hose to the bottom of the absorber.

9. Open the 2" bypass on PSV-X01-30 to atmosphere. Open the ¾" vent valves on the level columns.

10. Steam purge the column for minimum 36 hours.

9.0 SHORT TERM SHUTDOWN

The MEA/CO2 Removal Section may be shut down for a short duration because of:

1. Shutdown of equipment within the train.

2. Maintenance being required on a vital piece of equipment within the train affecting this Section.

If the shutdown does not involve the MEA solution pumps, the Absorber column and regeneration column can remain in service at a reduced flow. The required actions necessary will be determined by the type of shutdown.

The system should be restarted following the applicable procedure when the source of the trip has been rectified.

The duration of a shutdown involving maintenance will depend on the complexity of the repairs. Subsequent start up should follow the relevant sections of the procedure given elsewhere in this Operating Manual.



MEA-CO2 REMOVAL

10.0 QUALITY CONTROL

The Absorber overheads vapour stream is continuously monitored for quality by the on-line analyser (Gas chromatograph) AT-X01-38 via the sampling point AE-X01-38 which is located upstream of the 20" block valve to the dehydration section.

The analyser measures the content of CO2, if any, in the stream (Composition Analysis).

The CO2 specification of the overheads vapour is maintained by controlling the operation of the CO2 Absorber Column. If the correct operating parameters (temperature, LEAN MEA flow, and MEA concentration) are maintained, the overheads vapour from the Absorber will be on specification. Any variation in these process variables can have a significant impact on the overhead vapour CO2

content

For regular laboratory analysis, the following sampling points are provided:

AE-X01-38 Absorber overhead product, gas chromatograph analyser

SC-3: Lean MEA on the Outlet of X01-E-503B shell side.

SC 3B Lean MEA, inlet of X01-E-503B shell side.SC-5: Acid gas condensate X01-G-502 overheads.

Laboratory analysis of the samples taken via the Analyser sample connection can also be used to verify the accuracy of the on-line analyser AT-X01-38.

In addition to the regular samples, additional samples should be taken whenever the quality of a product stream is in question.

The maximum allowable CO2 content in the Absorber overheads is 90 ppm.

In addition to process samples taken throughout the system, there are Corrosion probes installed at various points to measure the effects of corrosion in the MEA/ Acid gas system.

X01-J-506 Suction piping (Acid gas condensate pump)

Inlet shell side of X01-E-503A (Lean MEA out of Regenerator)



MEA-CO2 REMOVAL

X01-E-501 shell side outlet (Regenerator Overhead condenser)

These are used to assist in determining the rate of corrosion inhibitor injection.

11.0 PROTECTIVE SYSTEMS AND EMERGENCY SHUTDOWN

There are three levels of protection:

1. Tertiary Protection:

This protection is represented by the control valves (PVs, FVs, and LVs). During normal operation, these control valves when operating satisfactorily will keep the system within the specified operating parameters and hence keep the system under safe conditions.

2. Secondary Protection:

This protection is represented by the emergency shutdown valves (XVs) which either close or open to keep the system under safe operating conditions in the event of control valves failures, mal-operation or in an emergency situation.

The system is provided with depressurisation valves (ED) for use in an emergency. The use of these valves is usually preceded by an ED initiation.

The ED valves cannot be positioned. They are either open or closed. The ED valves are provided with secured air supply which will permit the opening and closing of the valves three times in the event of an instrument air failure. Activation switches are located in the CCR.

If all the ESD valves contained within one LNG Train were opened simultaneously, the vapours released would most likely exceed the design capacity and hence the pressure rating of the LNG Emergency Flare System.

3. Primary Protection:

This is the ultimate protection and is presented by the safety relief valves: PSVs. In this case, when the secondary and / or the tertiary protection fail to keep the system under safe operating conditions, the relief valves open.



MEA-CO2 REMOVAL

11.1 Shutdown Systems

The CO2 Removal/MEA System has been provided with a number of trip systems to protect equipment and personnel and prevent hazardous operating conditions from occurring. These systems, which are activated in the CCR, can be separated into two areas as follows:

1. The overall emergency shutdown system.2. Individual equipment emergency shutdown.

A number of these trips are simple and self-explanatory and therefore require no further explanation. However, there are a number of trips that are more complicated and require further clarification.

Refer to the following Cause and Effect Charts:

C&E Chart No. CE-85-X01-02 CO2 Removal/MEA Section

11.1.1 ESD System

The inlet of each process train is provided with a motor operated valve JV-X01-70. This valve is interlocked with various process unit trips and will close automatically under the following conditions:

FSHH-X01-05 High feed gas flow set at 360,000 NM3/hr (10 second time delay).

HS-X01-230A at the LCR (Emergency Depressuring system)

HS-X01-230B at the CCR (Emergency Depressuring system)

HS-X01-227A at the LCR (Process train shutdown system)

HS-X01-227B at the CCR (Process train shutdown system)

XS-X00-279 Process Train Fire and Gas detection system.

HS-X01-701A Manual switch at LCR.

HS-X01-701B Manual switch at CCR.

Downstream of JV-X01-70 is the main Feed gas pressure control valve PV-X01-04. It closes automatically under the following conditions:

FSHH-X01-05 High feed gas flow set at 360,000 NM3/hr (10 second time delay).

PSLL-X00-00A/B MCR Intercooler water supply low pressure.



MEA-CO2 REMOVAL



HS-X01-227A at the LCR (Process train shutdown system)

HS-X01-227B at the CCR (Process train shutdown system)

XS-X00-279 Process Train Fire and Gas detection system.

Associated with FSHH X01-05 is a feed gas low low flow switch FSLL-X01-05 set at 70,000 NM3/hr, which initiates the following actions:

OPENS:

1st stage MCR Anti surge valve FV-X05-19

2nd stage MCR anti surge valve FV-X05-29

CLOSES:

Main exchanger valve CrV-X05-06

MCR Liquid to Main exchanger HV-X06-03

MCR Liquid to Main exchanger HV-X06-02

LNG from main exchanger TV-X06-12

Main exchanger valve FV-X06-15

The Process Train shutdown system and Fire and Gas Detection systems initiate the following actions via HS-X01-227A/B and HS-X00-279:

Stops X01-J-505 MEA sump pump.

Stops X01-J-504 MEA solution pump.

Closes FV-X01-29 Lean MEA to absorber.

Closes PV-X01-215 MEA flash drum vapour.

Stops X01-J-506 Acid gas condensate pump.

Closes PV-X01-04 Feed gas pressure control

Closes JV-X01-70 Feed gas Motor valve.

Closes XV-X01-211

Closes XV-X00-271



MEA-CO2 REMOVAL

Closes FV-X00-078

Closes FV-X00-077

Stops pumps, X01-R-502J, X01-R-503J, and X01-J-510/511.

The Emergency Depressuring system operates in the following manner in the case of an emergency:

XV-X01-202 can be OPENED or CLOSED by HS-X01-202 in the CCR.

XV-X01-202 will OPEN:



This valve will only open after receiving a permissive signal from ZSC-X02-252 indicating that depressuring valve XV-X02-252A (Mercury removal drum) is closed.

11.1.2 Primary Protection System

11.1.2.1 CO2 Absorber

PSV-X01-30 (Absorber column overhead) set at 49.7 bar and relieving to atmosphere.

PSV-X01-35 (MEA Carbon filter) set at 63.8 bar relieving to atmosphere.

PSE-X01-23 (Feed Gas Preheater X01-E-506 shell side) set at 8.3 bar

PSV-X01-217 (MEA Flash drum) set at 12 bar relieving to the Regenerator reboiler outlet line.

11.1.2.2 MEA Regenerator

PSV-X01-14 (Regenerator overhead) set at 5.2 bar relieving to atmosphere.

PSV-X01-41 (Antifoam pump discharge) set at 52.2 bar relieving back to the antifoam mixing tank

PSV-X01-200 (Corrosion inhibitor pump discharge) set at 7.3 bar relieving back to the corrosion inhibitor-mixing tank.



MEA-CO2 REMOVAL

PSV-X01-03 (MEA Purifier shell side outlet) set at 5.47 bar relieving to atmosphere.

PSE-20152/40158 (MEA Storage tanks 201-G-501/401-G-505) Pressure/Vacuum relief to atmosphere. Set at + 35 mbar and –20 mbar respectively.

12.0 SAFETY HAZARDS

12.1 General

The role of the MEA/CO2 System is to remove the CO2 from the natural gas stream with a chemical solution of Monoethanolamine (MEA).

The overheads vapour from the absorber is lighter than air and will rise and dissipate when discharged into the atmosphere.

Except for methane which is lighter than air and will rise and dissipate when discharged into the atmosphere, ethane, propane, butanes and heavier hydrocarbons have the same or higher density as air and therefore, any leakage or spillage will concentrate and accumulate at low points such as drains, ditches, etc., spreading at ground level to form a combustible mixture with air. In this context, all the leaks and spills should be stopped, contained and dispersed quickly so that fire and explosion risks are prevented or minimised.

Great care should be taken to see that all pumps and motors are well lubricated and maintained to ensure that mechanical defects do not become sources of ignition. In addition, any maintenance work in the near vicinity of a leak should be stopped, as there is the danger of tools creating sparks unless special non-sparking tools are being used.



MEA-CO2 REMOVAL

High vapour concentrations of all components will cause oxygen deficiency while lower concentrations will have an anaesthetic effect. Personnel must not enter an area suspected to be deficient of oxygen until the vapours and their causes have been cleared and the appropriate gas test shows the oxygen content will sustain life, i.e. about 20% oxygen. The atmosphere should also be tested for toxic material.

If an inert atmosphere must be maintained, personnel must be equipped with self contained breathing apparatus and enter the area using the appropriate safety code for such work, e.g. standby personnel with extra breathing apparatus sets, belt and safety line to effect a rescue in case of an emergency.

There are potential cold hazards due to the low processing temperature of the treated gas, propane and the MCR circuits. Any contact of the skin can cause severe burn type injuries. If such a contact occurs, immediately flush the affected area with slightly warm water for approximately five minutes but DO NOT TOUCH THE INJURED AREA. After flushing with warm water, seek medical attention for the injury. Personnel working in areas of low temperature fluids to minimise the risk of injury should always wear protective clothing and gloves.

12.2 Monoethanolamine (MEA)

Refer to the appropriate Material Safety Data Sheets (MSDS) supplied by the manufacturer for additional information.

12.2.1 Flammability

MEA is not classified as a flammable material. It has a Flash point of 91° C and generally does not pose a hazard except in cases of large spills or leaks.

12.2.2 Handling and Safety Precautions

Oral toxicity. Serious toxic effects may result in the event of ingestion in substantial quantities.

Eye irritation. MEA is strongly alkaline and has significant irritating actions on the eyes.

Skin irritation. MEA is strongly alkaline and has significant irritating actions on the skin. The undiluted material and solutions containing more than 10% MEA are capable of producing considerable injury to the skin.



MEA-CO2 REMOVAL

12.2.3 Safe Handling

During the handling and transfer of MEA, personnel should be trained in the use of and provided with personnel protective equipment. Rubber gloves, rubber suits, goggles, and face shields. Safety showers and eyewash stations should also be provided nearby.

In the event of exposure, thoroughly wash the affected area with water for minimum 15 minutes and seek medical assistance.

12.3 Combustible Mixtures

1. Never admit flammable vapours or liquids into a circuit containing air or vise versa until you have purged the circuit or vessel with nitrogen and carried out tests to ensure that the level of air is down to a safe level, less than 1% O2.

2. When shutdown, always keep a slight positive pressure inside the circuits or vessels to avoid the ingress of air or vapours unless the shutdown was for inspection and maintenance reasons. In this case, purge the system concerned with nitrogen first prior to admitting air.

3. Do not vent large amount of cold hydrocarbon vapours through atmospheric vents as cold vapours are generally denser than air and could form low points pockets of flammable gas. Also avoid venting large amounts of air into flammable gas vents as this could form an explosive atmospheric inside the pipe.

12.3.1 Ventilation and Cleaning of Vessels and Lines

1. When vessels and lines are opened for inspection, repairs or cleaning, the system must first be purged with an inert gas (N2) to remove the combustible mixture. After the system is inert, air is introduced to prepare the system for inspection.

2. Proper ventilation will minimise the danger of forming flammable gas pockets or a toxic atmosphere. This can be achieved by opening top and bottom man-ways and lines in vessels and aiding the movement of air by using an air mover. Under no circumstances are personnel allowed in vessels and piping unless the atmosphere is between 20.0 – 21.5% O2.

3. Before using any cleaning agents, refer to supplier’s instructions and check for toxicity that could occur by breathing of the vapours and absorption through the skin. Wear the protective safety gear and follow the special handling and safety precautions as recommended by the chemical register for the particular agent that is being used.



MEA-CO2 REMOVAL

13.0 APPENDICES

13.1 DCS Schematics

13.2 Process Flow Diagrams (PFD's)

PFD-85-X01-PF-10BPFD-85-X00-M-10APFD-85-X00-M-10B

13.3 Process and Instrument Diagrams (PID's)

PID-30-920-10.2/3PID-85-X00-24.1PID-85-X00-21.2PID-85-X01-10.1PID-85-X01-10.2PID-85-X00-24.1PID-85-X01-10.3

13.4 Cause and Effect Charts

CE-85-X01-02 MEA/CO2 Removal

S01 MEA

Documents

regenerator system

co2 absorber system

system preparation

sump system

purification system

filtration system

natural gas feed

esd system