process description

PROCESS DESCRIPTION

Doc. No.:S090768.231-3.00-002-A-E

Job No.: 090768

Rev. B of 29

LPG Train-4 Project at MAA RefineryContract CA/CSPD/0009

LPG Train-4 Projectat

MAA Refinery

Contract CA/CSPD/0009

PROCESS DESCRIPTION(S090768.231-3.00-002-A-E)

B 14-Oct-11 Revised as Marked J.M.Jung J.M.Mun G.P.Moon S.K.KIM

A 7-Sep-10 Issue For Review G.P.Moon S.M.Choi B.J.Yi S.K.KIM

REV. DATE DESCRIPTION ORIGINAL/REVISED BY

CHECKEDBY

CHECKEDBY

APPROVEDBY

PROCESS DESCRIPTION

Doc. No.:S090768.231-3.00-002-A-E

Job No.: 090768

Rev. B of 29

TABLE OF CONTENTS

1. GENERAL ..................................................................................................................... 31.1 Plant Facilities .......................................................................................................................... 4

2. FEED PRETREATMENT (UNIT 231) ............................................................................. 52.1 PFD: Feed Gas Collection Header 090768.231-3.00-101-A-B .................................................. 52.2 PFD: Feed Gas Compression 090768.231-3.00-102-A-B & 090768.231-3.00-103-A-B ............ 52.3 PFD: Feed Gas Dehydration 090768.231-3.00-104-A-B & Fired Heater For Dryer

090768.231-3.00-105-A-B ....................................................................................................... 62.4 PFD: Condensate and LPG Collection Headers 090768.231-3.00-106-A-B ............................. 82.5 PFD: Condensate and LPG Feed Dehydration 090768.231-3.00-107-A-B ............................... 92.6 PFD: HP Fuel Gas Conditioning 090768.231-3.00-108-A-B ................................................... 11

3. NGL RECOVERY (UNIT 232) ...................................................................................... 133.1 PFD: NGL Recovery 090768.232-3.00-101-A-B ...................................................................... 133.2 PFD: Condensate Stripping 090768.232-3.00-102-A-B .......................................................... 13

4. NGL FRACTIONATION (UNIT 233) ............................................................................. 144.1 PFD: Deethaniser 090768.233-3.00-101-A-B .......................................................................... 144.2 PFD: Depropaniser 090768.233-3.00-102-A-B ........................................................................ 154.3 PFD: Debutaniser 090768.233-3.00-103-A-B .......................................................................... 16

5. PRODUCT TREATING (UNIT 234) .............................................................................. 175.1 PFD: Propane Product Treating 090768.234-3.00-101-A-B .................................................... 175.2 PFD: Butane Product Treating 090768.234-3.00-102-A-B ...................................................... 18

6. REFRIGERATION & DEEP REFRIGERATION (UNIT 235) ......................................... 216.1 PFD: Refrigerant System (1/2) 090768.235-3.00-101-A-B ...................................................... 216.2 PFD: Refrigerant System (2/2) 090768.235-3.00-102-A-B ...................................................... 22

7. SOUR WATER STRIPPING (UNIT 236) ...................................................................... 237.1 PFD: Sour Water Stripper System (1/2) 090768.236-3.00-101-A-B ........................................ 237.2 PFD: Sour Water Stripper System (2/2) 090768.236-3.00-102-A-B ........................................ 23

PROCESS DESCRIPTION

Doc. No.:S090768.231-3.00-002-A-E

Job No.: 090768

Rev. B of 29

1. GENERAL

Feed Gas supplied to LPG Train-4 facilities consist of mixture of Associated Gas andCondensate from the KOC Gathering Centers Southeast Kuwait (SEK) and North Kuwait(NK) oilfields. In addition, existing KNPC Refinery Gases from the Shuaiba (SHU) AGRPand the Mina Al-Ahmadi (MAA) AGRP are supplied to the LPG Train-4 Plant facilities.Future Non-associated Gas from the Dorra Gas field is considered in the design cases.

The range of the Feed Gas composition is covered by the six defined design cases, whichgovern the design of Liquefaction and Fractionation Sections. And JT valve operationcase of Winter Without Dorra feed is also considered in design. These cases arepresented in the Design Basis and summarized below:

1. Summer Case Without Dorra2. Summer Case With Dorra3. Winter Case Without Dorra4. Winter Case With Dorra5. Rich Case6. Lean Case7. JT Valve Operation Case

A separate design Feed quality has been defined to represent the maximum content of 2.5%CO2 and 2000 ppm H2S. These Feed Gas conditions are presented in the Process DesignBasis.

To support the operations of the LPG Train-4 Plant, C3 Refrigeration and general UtilityFacilities are provided. These facilities consist of Fuel Gas System, Waste Heat RecoverySteam Generation System, Sea Water System, Closed Cooling Water System, NitrogenGeneration System, Instrument and Plant Air Systems, Water Treatment and DistributionSystems, Pressure Relief and Flare, Liquid Disposal Systems, Fire Fighting System, andEffluent Treating, etc.

The design of the NGL section is based on the GSP (Gas Sub-cooled Process), which is aTurbo Expander, based cryogenic technology. The GSP (Gas Sub-cooled Process) wasselected among 4 candidate processes, which are two open-art and two licensed processes,i.e. GSP (Gas Sub-cooled Process, Open Art), OHR (Over Head Recycle, Open Art), SFR(Split Flow Reflux, Licensed by Ortloff), and the CRR (Cold Residue Recycle, Licensed byOrtloff) during the development of the Feasibility Study by Fluor Daniel.

This plant capacity is designed to process 805 MMSCFD of Feed Gas and 106.3 MBPD ofexternal Condensate in addition to the Condensate produced in the NGL Recovery Sectionof the process. Product Recoveries of at least 75% C2, 97% C3 and 99% C4 are expected.The Percent Recovery varies based on the Feed composition. Among the 6 different FeedCases, the Lean Case will have a higher Percent Recovery than the Rich Case.

Notes: This Process Description is based on the Case 1 “Without Dorra Summer” ofProcess Flow Diagrams submitted on July 04, 2008, Revision B (Issued for Pre-Hazop).Any future changes in the Process Flow Diagrams may require changes in this ProcessDescription.

PROCESS DESCRIPTION

Doc. No.:S090768.231-3.00-002-A-E

Job No.: 090768

Rev. B of 29

1.1 Plant Facilities

The Plant facilities are provided as follows to allow operations for 6 different cases:

Feed Pretreatment Unit (Unit 231)- Two gas turbine driven compressor trains to get driving force of ethane

recovery.- Feed Gas, Condensate and LPG Dehydration to prevent ice and hydrate

formation in the downstream NGL Recovery Unit (Unit 232) which wouldcause blockage of lines and equipment.

- Mercury Guard Bed is provided downstream of the Feed Gas Dehydrator.The purpose of Mercury Guard Bed is to remove trace quantities of mercurythat could be present in the feed to the NGL Recovery Unit (Unit 232) toprotect the brazed aluminum plate heat exchanger against rapid corrosionof aluminum. Mercury, even in trace quantities, has been found to corrodealuminum rapidly under certain conditions.

NGL Recovery Unit (Unit 232)- The purpose of the NGL Recovery Unit (Unit 232) is to produce and recover

the C2 heavier component. The selected process is GSP process which isusing Turbo Expander and C3 Refrigeration System as a cooling medium.

- Condensate Stripping System is to separate stripped condensate from thefeed condensate and to inject separated light ends into the Demethaniser(V-232-001).

NGL Fractionation Unit (Unit 233)- Single NGL fractionation facilities including Deethaniser, Depropaniser,

Debutaniser system. The objectives of a fractionation unit are:- To produce ethane, propane, butane, pentane and KNG for using as a fuel

gas or storage.

Product Treating Unit (Unit 234)- Propane sweetening and drying- Butane sweetening and drying- Purpose of Propane and Butane Treatment Facilities are to remove the

residual mercaptan and sulphur compounds (H2S, COS) in order to meetcommercial grade specifications.

Propane Refrigeration & Deep Refrigeration System (Unit 235)- The purpose of C3 Refrigeration System is to provide main cooling duty to

liquefying the C2 heavier component.- The purpose of Deep Refrigeration System is to provide cooling duty for

propane product cooling down to -49 oF (-45 oC)

Sour Water Stripping Unit (Unit 236)- Sour water stripping unit are provided with inlet feed drums, stripping tower

and associated equipment, etc. The purpose of sour water stripping unit isto strip out H2S in sour water. The H2S gas is sent to existing SRU

PROCESS DESCRIPTION

Doc. No.:S090768.231-3.00-002-A-E

Job No.: 090768

Rev. B of 29

2. FEED PRETREATMENT (UNIT 231)

2.1 PFD: Feed Gas Collection Header 090768.231-3.00-101-A-B

At the front of LPG Train-4 facilities, there are receiving facilities consisting of a PigReceiver and Slug Catcher, which are part of the existing facilities. South East Kuwait(SEK) and North Kuwait (NK) Feed Gases and Condensates are directly introducedfrom those existing facilities. The Mina Al-Ahmadi and Shuaiba Feed Gases areintroduced through the existing AGRP facilities.

Because of previous operations and the known possibility of entrained liquids andwater being carried along with the Feed Gases from the SEK and the NK GatheringCenters and Booster Compressor Stations, and gas stream from Shuaiba AGRP thesethree streams are combined and processed in the Feed Gas Separator, V-231-003.This equipment is designed to separate the Vapour, Hydrocarbon Liquids and Waterinto separate streams.

The vapour from this vessel is combined with the vapour streams from the Mina Al-Ahmadi and the Shuaiba AGRPs to be compressed in the Feed Gas Compressor, C-231-001 A/B. The Hydrocarbon Liquids or Condensate is routed to the CondensateFeed Drum, V-231-011. The collected Sour Water is routed to the Sour Water FeedSeparator, V-236-002.

2.2 PFD: Feed Gas Compression 090768.231-3.00-102-A-B & 090768.231-3.00-103-A-B

Feed Gas Compressor System consists of two identical trains to maximise operationflexibility and uniformity of gas turbine selection. This description will be written fortrain A due to identical train design.

The Feed Gas from the Feed Gas Separator, V-231-003, and the Feed Gas from theMina Al-Ahmadi and Shuaiba AGRPs is routed to the Feed Gas Compressor SuctionDrum, V-231-004A. The Feed Gas then separated and routed to the two compressortrains.

The half of feed stream enters Feed Gas Compressor Suction Drum, V-231-004A,which serves as a safeguard for the Compressor, separating out any liquids before theFeed Gas is compressed. This vessel contains the lower sump to collect bulkcontaminants and slug from the vessel’s first stage and Cyclotube with independentsecond stage sump to remove and collect entrained contaminants from the vapourstream.

The suction line to the Compressor contains pressure, temperature and flow elementsthat relay information to the Anti-Surge Controller. In addition, a pressure-controlleron the inlet adjusts the flow of Feed Gas by controlling the Feed Gas from the AGRPsand the combined Feed gas from the SEK and NK fields.

The Feed Gas is then compressed from a pressure of 507.9 psig (35.0 barg) to apressure of 1139.4 psig (78.6 barg). The inlet temperature to the Feed GasCompressor is 96.8 OF (36.0 OC) while the outlet temperature is 220.4 OF (104.7 OC).The discharge line from the Compressor contains pressure and temperature elements

PROCESS DESCRIPTION

Doc. No.:S090768.231-3.00-002-A-E

Job No.: 090768

Rev. B of 29

that relay information to the Anti-Surge Controller. In addition, a pressure-controlleradjusts the speed of the Compressor through the speed-controller and the GasTurbine. The Compressor is also equipped with an Anti-Surge line to theCompressor suction, to maintain the flow of Feed Gas through the Compressor. Andto keep the Compressor away from the surge line within reasonable limits.

The compressed Feed Gas is cooled in the Feed Gas Compressor Discharge AirCooler, E-231-001A, to a temperature of 140 OF (60 OC) followed by the Feed GasCompressor Discharge Water Cooler, E-231-002 A~D, to a temperature of 104 OF (40OC). During this cooling process, water and some hydrocarbon liquids can separate;therefore, the Feed Gas is routed to the Feed Gas Compressor Discharge Drum, V-231-005A, where the vapour, hydrocarbon liquids and water can be separated androuted separately. The hydrocarbon liquids or Condensate will be routed to theHydrocarbon Closed Sump Drum, V-237-010. The Sour Water will be routed to theSour Water Feed Separator, V-236-002. The separated, compressed and cooledFeed Gas will be routed to the Feed Gas Dehydrator Inlet Filter, F-231-002 A/B. Inaddition, KNPC has added a Feed Gas Sub-cooler exchanger, E-231-006A/B, that willheat Raw NGL and cool the Feed Gas to a temperature of approximately 95 OF (35OC).

2.3 PFD: Feed Gas Dehydration 090768.231-3.00-104-A-B & Fired Heater For Dryer090768.231-3.00-105-A-B

Adsorption (See Figure 1 & 2)

The wet Feed Gas enters the Dehydration section where it is first filtered in the FeedGas Dehydrator Inlet Filter, F-231-002A/B. This filter separator removes anyentrained or solid particles that may enter the gas stream from the connecting piping.These particles, if not removed, would deposit on the solid molecular sieve desiccantand eventually reduce its capacity for water adsorption. The wet Feed Gas (Water @803 ppmv, 40OC & 74.6 bara) enters three (3) of the five (5) Dehydrators that areoperating in the dehydration mode. The flow of the Wet Feed Gas is downwardthrough the desiccant. After passing through the molecular sieve desiccant, theexiting Feed Gas will be dried to a concentration of Max. 0.1 ppmv in the exiting FeedGas. Of the other two (2) of the five (5) dehydrators, one will be in theRegeneration/Cooling mode and the other in a Stand-by mode.

Upon exiting the Dehydrator, the Feed Gas enters the Dry Feed Gas After Filter, F-231-003 A/B, where molecular sieve particulates are removed, down to 5 microns ( )in size. The filtered Gas exiting the Dry Feed Gas Filter enters the Mercury Guard Bed,V-231-002, where Mercury in the Feed Gas (100 g/Sm3) will be removed by beingadsorbed on a sulphur-impregnated activated carbon bed. After passing through theMercury Guard Bed, the Feed Gas enters the Mercury Guard Filter, F-231-004A/B,where any carbon particulates, down to 5 microns ( ) in size, are removed. The driedand essentially Mercury free (Max. 10 g/Sm3) Feed Gas is routed to the Natural GasRemoval Unit (Unit 232).

Depressurising

PROCESS DESCRIPTION

Doc. No.:S090768.231-3.00-002-A-E

Job No.: 090768

Rev. B of 29

After each of the Dehydrator vessels approach water saturation or capacity, Wateranalysers that are placed in the bottom section of the Mol Sieve indicate thatbreakthrough will occur. This means that the Dehydrator has to be depressurisedand then regenerated, cooled and repressurised to be ready for the next cycle in theoverall operation. First, each vessel is switched to the Regeneration mode and thendepressurised, with the vapour flowing from the bottom-up. This operation occurs forapproximately 30 minutes (0.5 hr) with the gas being routed to the Dryer RegenerationAir Cooler, E-231-003, the Spent Regeneration Gas KO Drum, V-231-006, and then tothe High Pressure Fuel Gas system via the Dryer Regeneration Compressor system,or the Low Pressure Fuel Gas system via the pressure-control valve on the SpentRegeneration Gas KO Drum, V-231-006. The pressure of V-231-006 is controlled bysplit range control with LPFG and HPFG route. During normal operation, theregeneration gas will be routed to HPFG via the Dryer Regeneration CompressorSystem. When the pressure in Spent Regeneration Gas KO Drum, V-231-006, ishigher than the set point of pressure controller in LPFG route, then the controller inLPFG will take over the pressure control of Spent Regeneration Gas KO Drum, V-231-006.

Regeneration – Heating (See Figure 2)

Once the vessel is depressurised and verified by the pressure gauge on the outlet lineof the vessel, the regeneration-heating step begins. The regeneration-heating stephas an up-flow direction, from the bottom to the top of the vessel. High PressureFuel Gas from the Ethane Recovery Plant (ERP) or Residue Gas from the LPG Train-4 Plant can be used for regeneration-heating gas. This gas first flows to the DryerRegeneration Gas Preheater, E-231-004A/B, where it is heated to 426.6 OF (219.2 OC)and then to the Dryer Regeneration Gas Heater, H-231-002, where it is heated to atemperature of 590 OF (310 OC). Both the Preheater and Heater have sufficient over-design to meet or exceed these required process conditions. The Hot Gas from theDryer Regeneration Gas Heater is then routed to the dehydration vessel that is under-going regeneration for approximately 3 hours. Because the regeneration process isan endothermic process (heat absorbed), the Spent Regeneration Gas exiting thedehydration vessel will be lower than the inlet temperature. The outlet gas will alsocontain more water than the inlet gas. This Spent Regeneration Gas is routed to thetube side of the Dryer Regeneration Gas Preheater, E-231-004A/B, where it is cooledto approximately 140 OF (60 OC) and water is condensed. The Spent RegenerationGas is then routed to the Spent Regeneration Gas KO Drum, V-231-006, where thefree water is separated from the Spent Regeneration Gas along with any hydrocarbonliquids that may also condense. The Sour Water is routed to the Sour Water FeedSeparator, V-236-002, and the hydrocarbon liquids to the Hydrocarbon Closed SumpDrum , V-237-010. The Spent Regeneration Gas vapour stream is then routed to theDryer Regeneration Compressor Suction Drum, V-231-008, the Dryer RegenerationCompressor, C-231-002, the Regeneration Compressor Discharge Air Cooler, E-231-007, the Regeneration Compressor Discharge Drum, V-231-007, and then on pressurecontrol to the High Pressure Fuel Gas system.

Regeneration – Cooling (See Figure 1 & 2)

The next step in the cycle is the Cooling step. Air operated valves (AOV) will need tobe switched to accommodate this step in the overall cycle. High Pressure Fuel Gas

PROCESS DESCRIPTION

Doc. No.:S090768.231-3.00-002-A-E

Job No.: 090768

Rev. B of 29

from the ERP or Residue Gas from the LPG Train-4 Plant (Cold Regeneration Gas) isrouted to the top of the Dehydrator vessel and flows downward through the molecularsieve desiccant, extracting heat from the vessel and desiccant. Initially the CoolingGas temperature will be hot as heat is absorbed from the vessel and molecular sievematerial. As time progresses, the temperature will drop until the exit temperatureapproaches the inlet temperature. The spent Cooling Gas is routed to DryerRegeneration Air Cooler, E-231-003, where the temperature is cooled to 140 OF (60OC) and then routed to the Spent Regeneration Gas KO Drum, V-231-006, the DryerRegeneration Compressor Suction Drum, V-231-008, the Dryer RegenerationCompressor, C-231-002, the Regeneration Compressor Discharge Air Cooler, E-231-007, the Regeneration Compressor Discharge Drum, V-231-007, and then on pressurecontrol to the High Pressure Fuel Gas system.

Repressurising

After the Dehydrator has been depressurised, regenerated and cooled, it is ready tobe put back on-line, so repressurising of the vessel is the next step. A slipstream ofDry Feed Gas, downstream of the Dry Feed Gas Filter and upstream of the MercuryGuard Bed, is routed to the Dehydrator to increase the pressure to approximately thefeed conditions. This will require the AOV on the outlet of the Dehydrator to beclosed. The flow continues until the pressure increases and reaches the pressure ofthe Dry Feed Gas. At this point the cycle is complete and the Dehydrator is ready forservice and placed on Stand-by.

Dryer Regeneration Gas Heater (See Figure 2): Only one (1) Dryer Regeneration GasHeater will be provided for the Feed Gas Dehydrators, the Condensate Dehydratorsand the LPG Dehydrators. Therefore, it is very important to make sure that the valvesequencing is worked out and that conflicts do not exist. Also, this Heater will alwaysoperate. If not during a heating step for one of the Dehydrators, it will operate on aminimum flow. A by-pass line equipped with an AOV is provided from the outlet ofthe Heater to the inlet of Dryer Regeneration Air Cooler, E-231-003, so thatRegeneration Gas can continually flow through the system.

2.4 PFD: Condensate and LPG Collection Headers 090768.231-3.00-106-A-B

Feed Condensate

The Condensate Feed can come from the Ethane Recovery Plant, North Kuwait, theSlug Catcher, South East Kuwait or the Mina Al-Ahmadi AGRP. In addition, severalsources of intermittent flows of Condensate can come from the Feed CondensateTransfer Pump, P-231-001 A/B; the Hydrocarbon Closed Drain Sump Drum Pumps, P-237-003A/B or the Condensate Dehydrator, V-231-012A/B, during the draining step.

The Condensate is collected in the Condensate Feed Drum, V-231-011, and theoutflow of Condensate to the Condensate Feed Pump, P-231-011 A/B, will be on flowcontrol reset by the level in the Drum.

LPG

PROCESS DESCRIPTION

Doc. No.:S090768.231-3.00-002-A-E

Job No.: 090768

Rev. B of 29

The LPG Feed can come from the Mina Al-Ahmadi Flare Gas Recovery (MAFG) Unit,the LPG Unit, the Mina Al-Ahmadi Fractionation Plant (MAFP), the HydrocrackingRecovery Unit (HCR) or the Mina Abdullah Refinery (MAB) LPG. In addition, anintermittent recycle stream of LPG from the LPG Dehydrator during the draining stepwill be re-processed.

The LPG is collected in the LPG Feed Drum, V-231-021, and the outflow of LPG to theLPG Feed Pump, P-231-021 A/B, will be on flow control reset by the level in the Drum.This control scheme will allow for fluctuations in the feed caused by the primarysources or that occurring during the “draining step” of the Molecular Sieve DehydrationBed.

2.5 PFD: Condensate and LPG Feed Dehydration 090768.231-3.00-107-A-B

Condensate Dehydration (See Figure 3)

The Condensate Feed from the Condensate Feed Pump, P-231-011 A/B, is routed tothe Condensate Inlet Filter, F-231-011 A/B, where particulates 5 microns ( ) andlarger are removed to avoid future blockage and a reduction in the adsorption capacityof the molecular sieve. This filter is spared so that the elements can be changed,during operation, by switching the spent filter to the spare filter.

The Condensate Feed is then routed to the Condensate Dehydrator, V-231-012 A/B,where the Condensate flows upward from bottom-to-top and the water is removedfrom saturation (~305 ppmw) to 1.0 ppmw. The Dry Condensate is then routed to theCondensate Outlet Filter, F-231-012 A/B, which is also spared for easy elementchange-out during normal operations. The dry and filtered Condensate is then routedto the Condensate Stripper, V-232-002.

LPG Dehydration (See Figure 3)

The LPG Feed from the LPG Feed Pump, P-231-021A/B, is routed to the LPG InletFilter, F-231-021A/B, where particulates 5 microns ( ) and larger are removed to avoidfuture blockage and a reduction in the adsorption capacity of the molecular sieve.This filter is spared so that the elements can be changed, during operation, byswitching the spent filter to the spare filter.

The LPG Feed is then routed to the LPG Dehydrator, V-231-022 A/B, where the LPGflows upward from bottom-to-top and the water is removed from a saturation level of~305 ppmw to 1.0 ppmw. The Dry LPG is then routed to the LPG Outlet Filter, F-231-022 A/B, which is also spared for easy element change-out during normaloperations. The dry and filtered LPG is then routed to the LPG KNG ProductExchanger, E-231-012 A/B, where the temperature of the LPG product is increased toapproximately 119.4 OF (48.6 OC) and then routed to tray 9 (numbered from bottom-up) in the Deethaniser, V-233-001.

Condensate / LPG Dehydrator Regeneration (See Figure 2 & 3)

PROCESS DESCRIPTION

Doc. No.:S090768.231-3.00-002-A-E

Job No.: 090768

Rev. B of 29

After the Condensate and LPG Dehydrators have gone through their respectiveadsorption cycles where water is removed down to 1.0 ppmw in each of the products,the Dehydrator is then ready to be regenerated. The following discussion applies toeach of these dehydration systems since the steps are the same except for the timespans of each of the steps.

The Dryer Regeneration Gas Heater, H-231-002, will be used to regenerate thesedehydrators in addition to the Feed Gas Dehydrators, V-231-001 A~E, previouslydiscussed.

Dehydrator Draining (See Figure 3)

The first step in regenerating these molecular sieve Dehydrators is to drain the liquidfrom the vessel. The Condensate is drained to the Condensate Feed Drum, V-231-011, and the LPG is drained to the LPG Feed Drum, V-231-021. This draining step isan intermittent step (approximately 60 minutes (one hour) in duration) that willincrease the level in the respective Feed Drum by approximately 500-600 mm, a levelthat can be slowly reduced by slowly increasing the flow of the respective Feed to theDehydrator. The draining step is assisted by the introduction of Dry Feed Gas tomaintain the pressure on the Dehydrator during the draining step. As the liquid isdrained from the vessel, the Dry Feed Gas may also displace Condensate / LPGliquids adsorbed onto the molecular sieve material, adding to the total time to drain thevessel and to get it prepared for the regeneration-heating step.

Condensate / LPG Dehydrator Regeneration – Heating (See Figure 2 & 3)

ERP High Pressure Fuel Gas (HPFG) will be the first choice for providing theRegeneration Gas (Hot) for the Condensate and LPG Dehydrators. The ERP HPFGwill first exchange heat in the Dryer Regeneration Gas Preheater, E-231-004 A/B,where it will be heated from 54 OF (12.2 OC) to approximately 426.6 OF (219.2 OC),exchanging heat from the Spent Regeneration Gas (Hot) exiting the Dehydratorsduring the regeneration step or the beginning of the cooling step. The ERP HPFG isfurther heated in the Dryer Regeneration Gas Heater, H-231-002, to a temperature of590 OF (310 OC) so that the vessel, which is being regenerated, will reach atemperature of 554 OF (290 OC), the temperature required to assure that the water hasbeen stripped from the mol sieve desiccant.

The hot Spent Regeneration Gas exiting the top of the vessel is routed to the DryerRegeneration Gas Preheater, E-231-004 A/B, where the stream is cooled toapproximately 140 OF (60 OC) against the ERP HPFG stream. The SpentRegeneration Gas (Hot) is then routed to the Spent Regeneration Gas KO Drum,where condensed water and hydrocarbons will separate from the Gas stream. Theremaining Gas stream is then compressed and cooled in the Dryer RegenerationCompressor, C-231-002, and the Regeneration Compressor Discharge Air Cooler, E-231-007. The Regeneration Compressor Discharge Drum is provided to collect anywater and hydrocarbons that may condense after being compressed and cooled to464 Psig (32 barg) and 113 OF (45 OC), respectively. Hydrocarbons will more thanlikely condense during the beginning of the Regeneration-heating step, when theRegeneration Gas is stripping residual Condensate and LPG from the respective MolSieve Units.

PROCESS DESCRIPTION

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Job No.: 090768

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Dryer Regeneration Compressor:The Dryer Regeneration Compressor will experience variations in flow from aminimum Nm3/hr flow to as high as 95,000+ Nm3/hr. In addition to the Anti-Surgevalve, a separate flow control scheme is to be developed to accommodate thesevariations in flow from the three Dehydration systems, based on the systematicopening and closing of the sequence valves around the Dehydration systems, as itproceeds through the various steps in the cycle.

Condensate / LPG Dehydrator Regeneration – Cooling (See Figure 3)

Regeneration Gas (Cold) will be used to cool the Dehydrator Beds after they havebeen regenerated and the water removed. Initially the Spent Regeneration Gasexiting the Bed will be hot since it will remove the heat contained in the vessel shelland the molecular sieve. To minimize energy consumption, the Spent RegenerationGas can be routed to the Dryer Regeneration Gas Preheater, E-231-004 A/B, as longas the temperature of the Spent Regeneration Gas exiting the bed on the cooling stepcan be utilized to preheat the Regeneration Gas to the Dryer Regeneration GasHeater, H-231-002. When the Dryer Regeneration Gas Heater is operating on theminimum flow, preheating this gas to the Heater may be a benefit and help to reduceenergy consumption.

Condensate / LPG Dehydrator Refilling & Repressurising (See Figure 3)

Once the beds have been regenerated and cooled, they have to be refilled with dryproduct and repressured to be ready for the next cycle. Dry LPG and Condensateproduct, respectively are used to refill and repressure the respective Dehydrationvessels. A slipstream of the dry product will be introduced at the bottom of the vesseland the vessel and the mole sieve will be refilled with liquid. Once the vessel is filledand the level switch (transmitter) on the top of the vessel is actuated, the filling stepwill stop and the vessel will be placed on Stand-by, ready for the next cycle.

2.6 PFD: HP Fuel Gas Conditioning 090768.231-3.00-108-A-B

The Wet Feed Gas from the Feed Gas Separator, V-231-003, and the Feed Gas fromthe Mina Al-Ahmadi and Shuaiba ARGPs after the Metering Station, 231-MT-2102is routed to the HP Fuel Gas Conditioning System – if required when the Feed GasCompressor, C-231-001 A/B are not in service.

The wet Feed Gas controlled by the flow of max, 403.3 MMSCFD based on withoutDORRA Summer Case will first exchange with the HP Fuel Gas/ Gas exchanger, E-231-031, where it will be cooled to 55.9 OF (13.3 OC). And then the cooled Feed Gas isfed to the HP Fuel Gas K.O. Drum, V-231-031 via the HP Fuel Gas Chiller, E-231-032,where it will be chilled to 10.1 OF (-12.2 OC) in order to obtain the LHV requirementapp. 1088 Btu/SCF) of HP Fuel Gas coming from the HP Fuel Gas K.O. Drum.Methanol is injected in the upstream of both heat exchangers to prevent ice andhydrate fomation. For the chilling of the Feed Gas, LP Propane Refrigerant is suppliedfrom the Propane Refrigerant Compressor MP Suction Drum, V-235-003 via the Level

PROCESS DESCRIPTION

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Job No.: 090768

Rev. B of 29

Control Valve, which is controlled by the Temperature Controller installed on the outletof the HP Fuel Gas Chiiler.

After chilling of the Feed Gas, the mixed phase flow is separated in the HP Fuel GasK.O. Drum, V-231-031, and then the gas stream is sent to the Residue Gas Headervia the HP Fuel Gas/ Gas Exchanger Tube Side, where it will be heated by the wetfeed gas up to app. 51.7OF (10.9 OC), and is sent to the upstream of the MeteringStation, 232-MT-2111, which will be connected to the existing HP Fuel Gas Header.The operating pressure of the HP Fuel Gas K.O. Drum shall be controlled by theflowrate of gas stream to the residue gas.

The HP Fuel Gas K.O. Drum bottom liquid is routed to the Feed Condensate Drum, V-231-011, as pumped by the HP Fuel Gas K.O. Drum pump, P-231-031 A/B, and is flowcontrolled reset by level control to the HP Fuel Gas K.O. Drum.

PROCESS DESCRIPTION

Doc. No.:S090768.231-3.00-002-A-E

Job No.: 090768

Rev. B of 29

3. NGL RECOVERY (UNIT 232)

3.1 PFD: NGL Recovery 090768.232-3.00-101-A-B

Dry Feed Gas from the Feed Gas Dehydrators enters this section and is split into twostreams, one stream which is cooled in the Feed – Residue Gas Exchanger, E-232-002, and the other stream cooled in the Combined Reboiler Exchanger, E-232-001.These two streams, after exiting their respective exchangers, are recombined androuted to the Dry Feed Gas Chiller, E-232-004 A/B. This combined stream is thenflashed adiabatically in the Chilled Feed Gas KO Drum, V-232-003A/B, wherehydrocarbon liquids are separated from the vapour stream. The majority of thecondensed hydrocarbon liquids is routed to tray 20 in the Demethaniser, V-232-001,while the vapour stream is separated and routed to the Demethaniser RefluxSubcooler, E-232-003, and the Turbo Expander, L-232-001. A small part of theliquids normally routed to tray 20 in the Demethaniser is re-routed to the DemethaniserReflux Subcooler, E-232-003, in order to meet the minimum Ethane Recoveryrequirements. The mixed phase exiting the Turbo Expander is then routed to tray 26in the Demethaniser, just below the packed section. The mixed phase exiting theDemethaniser Reflux Subcooler is routed to the top of the packed section, whereEthane and heavier components are washed down to the bottom trays and recoveredin the bottoms liquid.

The composition of the Demethaniser overhead vapour or Residue Gas is determinedto meet the minimum Ethane recovery requirements along with Propane and Butanerecoveries for the overall processing of Feed Gas, Condensate and LPG. To be surethat the bottoms product does not contain too much Ethane and lighter components,the Demethaniser Trim Reboiler, E-232-006, is being installed to operate on LP Steamand work in conjunction with the Combined Reboiler Exchanger, E-232-001, inmaintaining a consistent bottoms product composition.

The Condensate Stripper, V-232-002, Overhead stream is introduced on tray 5 of theDemethaniser so that the Ethane and lighter components can move up the columnwhile the Ethane and heavier components can be recovered in the bottoms, raw NGL,product.

The cold Residue Gas exiting the Demethaniser, V-232-001, exchanges heat in theDemethaniser Reflux Subcooler, E-232-003, and the Feed – Residue Gas Exchanger,E-232-002, before it is compressed in the Residue Gas Compressor, C-232-001, androuted to the Battery Limits of the plant, after being metered. The composition of thisstream will also be measured with an in-line analyser measuring H2S, C1, C2 C3 andCO2.

3.2 PFD: Condensate Stripping 090768.232-3.00-102-A-B

The Condensate Stripper, V-232-002, contains 20 trays for the stripping of Methaneand some Ethane from the dry Condensate feed. The Condensate Stripper overheadis routed back to the Demethaniser, where the Ethane and heavier components arecondensed and recovered in the raw NGL bottoms product. The CondensateStripper bottoms product is routed to tray 13 of the Deethaniser, V-233-001, whereEthane and lighter components are stripped from the Deethaniser bottoms product.

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PROCESS DESCRIPTION

Doc. No.:S090768.231-3.00-002-A-E

Job No.: 090768

Rev. B of 29

The Condensate Stripper Reboiler, E-232-008, provides the heat required for thestripping operation, using LP Steam as the heating medium. In addition to theCondensate Stripper Reboiler, a Condensate Stripper Side Reboiler, E-232-007, isprovided, recovering heat from the Condensate Stripper bottoms product and helpingto reduce the LP Steam load on the main reboiler. By distributing the reboiler loadswithin the trayed section (middle and bottom), the vapour and liquid traffic up anddown the column will also be reduced, resulting in a better and more efficient columndesign.

The temperature on tray 3 (numbered from the bottom to top) is measured and used tocontrol the LP Steam rate to the Condensate Stripper Reboiler. The hot CondensateStripper bottoms product is routed to the Condensate Stripper Side Reboiler, E-232-007, to recover heat and then to the Deethaniser as a feed to tray 13.

During Start-up, when the column overhead product may not be optimum, a provisionhas been made to allow the overhead vapour to be routed to the Low Prssure FuelGas by pressure control.

4. NGL FRACTIONATION (UNIT 233)

4.1 PFD: Deethaniser 090768.233-3.00-101-A-B

Feed streams to the Deethaniser consist of Raw NGL from the Demethaniser BottomsPumps, P-232-001 A/B/C, to tray 34; the Condensate Stripper bottoms from theCondensate Stripper Side Reboiler, E-232-007, to tray 13; and the dry LPG from theLPG KNG Product Exchanger, E-231-012, to tray 9.

The purpose of the Deethaniser is to strip out and fractionate the Ethane and lightercomponents in the feed streams, and to produce the highest recovery of Ethane andheavier components. To accomplish this, the column is equipped with a total of 54trays; 20 fractionating trays above the Condensate feed tray so that a minimum refluxrate can be employed while producing the quality and recovery of Ethane. Thisminimum reflux also helps to reduce the number of condensers required and thediameter of the Deethaniser column.

The Deethaniser Overhead Condenser, E-233-001, is a Core-in-Kettle type exchangerusing vaporizing MP Propane as the cooling medium. This partial condenserproduces an ethane-rich liquid, which is totally recycled back as reflux. Theoverhead vapour from the Deethaniser Overhead Receiver, V-233-006, or the EthaneProduct, is routed back to the Feed-Residue Gas Exchanger, E-232-002, to exchangeheat to the Feed Gas. The Ethane Product is then routed to the Propane RefrigerantSubcooler, E-235-002, before going to the metering station and then Storage.

The Deethaniser Reboiler, E-233-009 A/B, which uses condensing LP Steam as itsheat supply, provides the vapour for stripping and fractionation of the Ethane andlighter components in the column. The temperature of tray 5 is measured and usedto control the quantity of LP Steam to the Reboiler.

PROCESS DESCRIPTION

Doc. No.:S090768.231-3.00-002-A-E

Job No.: 090768

Rev. B of 29

The Deethaniser bottoms product is routed to the Depropaniser Feed Preheater, E-233-002, before being routed to the Depropaniser, V-233-002, on flow control reset bylevel control.

During Start-up, when the column overhead product may not be optimum or light endsneed to be vented, a provision has been made to allow the overhead vapour to berouted to the Low Pressure Fuel Gas system by pressure control.

4.2 PFD: Depropaniser 090768.233-3.00-102-A-B

The Feed stream to the Depropaniser consists of the preheated Deethaniser bottomsproduct from the Depropaniser Feed Preheater, E-233-002, to tray 39.

The purpose of the Depropaniser is to strip out and fractionate the Propane and lightercomponents in the feed stream, and to produce the highest recovery of Propane andButane components. To accomplish this, the column is equipped with a total of 66trays; 27 fractionating trays above the Depropaniser feed tray so that a minimum refluxrate can be employed while producing the purity and recovery of Propane. Thisminimum reflux also helps to reduce the number of condensers required and thediameter of the Depropaniser column.

The Depropaniser Overhead Condenser, E-233-003 A~D, consists of 4 large diameterfixed type Shell & Tube Heat Exchangers using Seawater as the cooling medium.This total condenser produces a propane-rich liquid, which is partially recycled back asreflux. The overhead liquid product from the Depropaniser Overhead Receiver, V-233-007, or the Propane Product, is routed to the Propane Product HP RefrigerantCooler, E-233-004, where the Propane Product is cooled to 59 OF (15 OC). ThePropane Product is then routed to the Propane Product Treaters, V-234-001A~D forSulphur control.

The Depropaniser Reboiler, E-233-010 A/B, which uses condensing LP Steam as itsheat supply, provides the vapour for stripping and fractionation of the Propane andlighter components in the column. The temperature of tray 5 is measured and usedto control the quantity of LP Steam to the Reboiler.

The Depropaniser bottoms product is routed to the Debutaniser, V-233-003, on flowcontrol reset by level control to tray 26 in the Debutaniser.


PROCESS DESCRIPTION

Doc. No.:S090768.231-3.00-002-A-E

Job No.: 090768

Rev. B of 29

4.3 PFD: Debutaniser 090768.233-3.00-103-A-B

The Feed stream to the Debutaniser consists of the Depropaniser bottoms product,which is routed to tray 26 of the Debutaniser.

The purpose of the Debutaniser is to strip out and fractionate the Butane and Pentanecomponents in the feed stream, and to produce the highest recovery of Butane andPentane components. To accomplish this, the column is equipped with a total of 37trays; 11 fractionating trays above the Debutaniser feed tray so that a minimum refluxrate can be employed while producing the purity and recovery of Butane. Thisminimum reflux also helps to reduce the number of condensers required and thediameter of the Debutaniser column.

The Debutaniser Overhead Condenser, E-233-005 A~D, consists of 4 large diameterfixed type Shell & Tube Exchangers using Seawater as the cooling medium. Thistotal condenser produces a butane-rich liquid, which is partially recycled back as reflux.The overhead liquid product from the Debutaniser Overhead Receiver, V-233-008, orthe Butane Product, is routed to the Butane Product HP Refrigerant Cooler, E-233-006,where the Butane Product is cooled to 59 OF (15 OC). The Butane Product is thenrouted to the Butane Product Treaters, V-234-002 A~D for Sulphur control.

The Debutaniser Reboiler, E-233-011 A/B, which uses condensing LP Steam as itsheat supply, provides the vapour for stripping and fractionation of the Butane andPentane in the column. The temperature of tray 3 is measured and used to controlthe quantity of LP Steam to the Reboiler.

The Debutaniser bottoms product, or the KNG Product, is pumped to the LPG KNGProduct Exchanger, E-231-012, by the KNG Product Pump, P-233-004 A/B, and thenrouted to the KNG Product Cooler, E-233-007 A/B, on flow control reset by levelcontrol.

The Pentane side stream is drawn from tray 6 and routed to the Pentane ProductAccumulator, V-233-009. The Pentane Product is then pumped by the PentaneTransfer Pump, P-233-005 A/B, and cooled via the Depropaniser Feed Preheater, E-233-002, and then further cooled in the Pentane Product Cooler, E-233-008 A/B, to100 OF (37.8 OC) before being routed to Storage.

The Debutaniser is also equipped with a Debutaniser Side Reboiler, E-233-012 A/B,which will be heated with hot, wet Feed Gas if additional reboiler capacity is required.Under normal operating conditions, this reboiler will not be used.


PROCESS DESCRIPTION

Doc. No.:S090768.231-3.00-002-A-E

Job No.: 090768

Rev. B of 29

5. PRODUCT TREATING (UNIT 234)

5.1 PFD: Propane Product Treating 090768.234-3.00-101-A-B

The Propane Product from the Propane Product HP Refrigerant Cooler, E-233-004A/B,is routed to the Propane Product Treater, V-234-001 A~D, where the Propane Productflows upward from bottom-to-top and the sulphur compounds (H2S, COS, and RSH)are removed to produce a Total Sulphur content of < 20 ppm(w) and a Copper StripCorrosion (1 hr @ 100 OF) of No.1. The treated Propane Product is then routed tothe Propane Product Treater Outlet Filter, F-234-001 A/B, which is spared for easyelement change-out during normal operations, and will remove particulates 5 microns

) and larger, to avoid future blockage or a reduction in the capacity of thedownstream heat exchangers. The treated and filtered Propane Product is thenrouted to the tube-side of the Propane Product MP Refrigerant Cooler, E-234-001,where the Propane is cooled to 14 OF (-10 OC), and then further cooled in the PropaneProduct LP Refrigerant Cooler, E-234-002 and Propane Product Deep RefrigerantChiller, E-234-003, to -49 OF (-45 OC) before being routed to Storage.

Propane Treater Regeneration (See Figure 4)

After the Propane Treaters have gone through their respective adsorption cycleswhere the sulphur compounds have been removed, the Treater is then ready to beregenerated. The following discussion applies to each of these Treater vessels sincethe steps are the same except for the offset of each of the time spans.

The Treater Regeneration Gas Heater, H-234-001, will be used to regenerate thePropane Product Treaters, V-234-001 A~D, in addition to the Butane Product Treaters,V-234-002 A~D. Before a Treater can be regenerated, the Propane contained in thevessel and molecular sieve has to be drained and recovered. The Propane isdrained to the Propane Regeneration Receiver, V-234-003, while being assisted withERP High Pressure Fuel Gas (HPFG) to maintain the vessel pressure.

Treater Draining (See Figure 4)

The Propane Product is drained in a downward manner to the Propane RegenerationFilter, F-234-002 A/B, and the Propane Regeneration Receiver, V-234-003. ThePropane recovered during the draining process will be pumped by the PropaneRegeneration Pump, P-234-001 A/B, and recycled back to the Propane Product HPRefrigerant Cooler, E-233-004 for reprocessing. This draining step is an intermittentstep (approximately 114 minutes (1.9 hour) in duration). The draining step isassisted by the introduction of ERP HPFG to maintain the pressure on the Treaterduring the draining step. As the liquid is drained from the vessel, the ERP HPFGmay also displace Propane liquids adsorbed onto the molecular sieve material, addingto the total time to drain the vessel and to get it prepared for the regeneration heatingstep. Typically, just before the Regeneration step (heating) is initiated, a final drain ofthe collected Propane is initiated to minimize all free Propane from the Treater.

PROCESS DESCRIPTION

Doc. No.:S090768.231-3.00-002-A-E

Job No.: 090768

Rev. B of 29

Propane Treater Regeneration – Heating (See Figure 4)

ERP High Pressure Fuel Gas (HPFG) will be the first choice for providing theRegeneration Gas (Hot) for the Propane Treaters. The ERP HPFG will firstexchange heat in the Treater Regeneration Gas Preheater, E-234-011 A/B, where itwill be heated from 54 OF (12.2 OC) to approximately 339 OF (170.5 OC), exchangingheat from the Spent Regeneration Gas (Hot) exiting the Treaters during theregeneration step or the beginning of the cooling step. The ERP HPFG is furtherheated in the Treater Regeneration Gas Heater, H-234-001, to a temperature of 590OF (310 OC) so that the vessel, which is being regenerated, will reach a temperature of554 OF (290 OC), the temperature required.

The hot Spent Regeneration Gas exiting the bottom of the vessel is routed to thePropane Regeneration Hot Gas Filter, F-234-005 A/B, and then the TreaterRegeneration Gas Preheater, E-234-011 A/B, where the stream is cooled toapproximately 203 OF (95 OC) against the ERP HPFG stream and then, further cooledthrough Propane Regeneration Hot Gas Cooler, E-234-012. The Spent RegenerationGas (Hot) is then routed to the Propane Regeneration KO Drum, V-234-005, wherecondensed hydrocarbons will separate from the Gas stream. The condensedhydrocarbon is routed to the Hydrocarbon Closed Drain system. The remaining Gasstream is then routed to the Low Pressure Fuel Gas or to the 175 Psig Refinery GradePropane Unit (RGPU), if Propane Vapour is used for Regeneration.

Propane Treater Regeneration – Cooling (See Figure 4)

Treated Propane Product liquid will be used to cool the Treater Beds (QuenchCooling) after they have been regenerated and the sulphur and water componentsremoved. This step will proceed from the bottom of the vessel and upward. Initiallythe Spent Propane Regeneration Gas exiting the top of the Bed will be hot, since it willremove the heat contained in the vessel shell and the molecular sieve, thus vaporisingthe Propane. To minimize energy consumption, the Spent Propane RegenerationGas can be routed to the Propane Regeneration Hot Gas Filter, F-234-005 A/B, andthe Treater Regeneration Gas Preheater, E-234-011 A/B, as long as the temperatureof the Spent Propane Regeneration Gas exiting the bed on the cooling step can beutilized to preheat the HPFG to the Treater Regeneration Gas Heater, H-234-001.Otherwise, the Spent Regeneration Gas will be routed to the Propane RegenerationAir Cooler, E-234-005, the Propane Regeneration Water Cooler, E-234-006 A/B, thePropane Regeneration Filter, F-234-002 A/B, and the Propane Regeneration Receiver,V-234-003.

Propane Treater Refilling (See Figure 4)

As the Quench Cooling step proceeds, the Refilling and Repressuring of the Treateralso proceeds. Treated Propane Product introduced at the bottom of the Bed willaccumulate in the vessel, cooling the vessel and its contents while refilling the vesselfor the next cycle. Once the vessel is filled and the level switch (transmitter) on thetop of the vessel is actuated, the Quench Cooling - Refilling step will stop and thevessel will be placed on Stand-by, ready for the next cycle.

5.2 PFD: Butane Product Treating 090768.234-3.00-102-A-B

PROCESS DESCRIPTION

Doc. No.:S090768.231-3.00-002-A-E

Job No.: 090768

Rev. B of 29

The Butane Product from the Butane Product HP Refrigerant Cooler, E-233-006, isrouted to the Butane Product Treater, V-234-002 A~D, where the Butane Productflows upward from bottom-to-top and the sulphur compounds (H2S, COS, and RSH)are removed to produce a Total Sulphur content of < 20 ppm(w) and a Copper StripCorrosion (1 hr @ 100 OF) of No.1. The treated Butane Product is then routed to theButane Product Treater Outlet Filter, F-234-003 A/B, which is spared for easy elementchange-out during normal operations, and will remove particulates 5 microns ( ) andlarger, to avoid future blockage or a reduction in the capacity of the downstream heatexchangers. The treated and filtered Butane Product is then routed to the tube-sideof the Butane Product Chiller, E-234-007, where the Butane is cooled to 14 OF (-10OC).

Butane Treater Regeneration (See Figure 4 & 5)

After the Butane Treaters have gone through their respective adsorption cycles wherethe sulphur compounds have been removed, the Treater is then ready to beregenerated. The following discussion applies to each of these Treater vessels sincethe steps are the same except for the offset of each of the time spans.

The Treater Regeneration Gas Heater, H-234-001, will be used to regenerate theButane Product Treaters, V-234-002 A~D, in addition to the Propane Product Treaters,V-234-001 A~D. Before a Treater can be regenerated, the Butane contained in thevessel and molecular sieve has to be drained and recovered. The Butane is drainedto the Butane Regeneration Receiver, V-234-004, while being assisted with ERPHPFG to maintain the vessel pressure.

Treater Draining (See Figure 5)

The Butane Product is drained in a downward manner to the Butane RegenerationFilter, F-234-004 A/B and the Butane Regeneration Receiver, V-234-004. TheButane recovered during the draining process will be pumped by the Butane RecyclePump, P-234-002 A/B, and recycled back to the Butane Product HP RefrigerantCooler, E-233-006 for reprocessing. This draining step is an intermittent step(approximately 114 minutes (1.9 hour) in duration). The draining step is assisted bythe introduction of ERP HPFG to maintain the pressure on the Treater during thedraining step. As the liquid is drained from the vessel, the ERP HPFG may alsodisplace Butane liquids adsorbed onto the molecular sieve material, adding to the totaltime to drain the vessel and to get it prepared for the regeneration-heating step.Typically, just before the Regeneration step (heating) is initiated, a final drain of thecollected Butane is initiated to minimize all free Butane from the Treater.

PROCESS DESCRIPTION

Doc. No.:S090768.231-3.00-002-A-E

Job No.: 090768

Rev. B of 29

Butane Treater Regeneration – Heating (See Figure 4 & 5)

ERP High Pressure Fuel Gas (HPFG) will be the first choice for providing theRegeneration Gas (Hot) for the Butane Treaters. The ERP HPFG is heated in theTreater Regeneration Gas Heater, H-234-001, to a temperature of 590 OF (310 OC) sothat the vessel, which is being regenerated, will reach a temperature of 554 OF (290OC), the temperature required.

The hot Spent Regeneration Gas exiting the bottom of the vessel is routed to theButane Regeneration Hot Gas Filter, F-234-006 A/B. The Spent Regeneration Gas(Hot) is then routed to the Butane Regeneration Hot Gas Cooler, E-234-013, and thenthe Butane Regeneration KO Drum, V-234-006, where condensed hydrocarbons willseparate from the Gas stream at approximately 140 OF (60 OC). The condensedhydrocarbon is routed to the Hydrocarbon Closed Drain system. The remaining Gasstream is then routed to the Low Pressure Fuel Gas or to the 175 Psig Refinery GradePropane Unit (RGPU), if Propane Vapour is used for Regeneration.

Butane Treater Regeneration – Cooling (See Figure 5)

Treated Butane Product liquid will be used to cool the Treater Beds (Quench Cooling)after they have been regenerated and the sulphur and water components removed.This step will proceed from the bottom of the vessel and upward. Initially the SpentButane Regeneration Gas exiting the top of the Bed will be hot, since it will remove theheat contained in the vessel shell and the molecular sieve, thus vaporising the Butane.The Spent Butane Regeneration Gas will be routed to the Butane Regeneration AirCooler, E-234-009, the Butane Recycle Water Cooler, E-234-010 A/B, the ButaneRegeneration Filter, F-234-004 A/B and the Butane Regeneration Receiver, V-234-004. Condensed Butane will be recycled back to the process for reprocessing toavoid contamination.

Butane Treater Refilling (See Figure 5)

As the Quench Cooling step proceeds, the Refilling and Repressuring of the Treateralso proceeds. Treated Butane Product introduced at the bottom of the Bed willaccumulate in the vessel, cooling the vessel and its contents while refilling the vesselfor the next cycle. Once the vessel is filled and the level switch (transmitter) on thetop of the vessel is actuated, the Quench Cooling - Refilling step will stop and thevessel will be placed on Stand-by, ready for the next cycle.

PROCESS DESCRIPTION

Doc. No.:S090768.231-3.00-002-A-E

Job No.: 090768

Rev. B of 29

6. REFRIGERATION & DEEP REFRIGERATION (UNIT 235)

6.1 PFD: Refrigerant System (1/2) 090768.235-3.00-101-A-B

The Propane Refrigeration System is a closed-system that provides low temperaturecooling and chilling to the Propane and Butane product streams. The composition ofthe propane refrigerant is:

Ethane & Lighter Maximum 0.5 mol%Propane Minimum 99.0 mol%Butane and Heavier Maximum 0.5 mol%

Propane Make-up to this system is taken downstream of the Propane Product DeepRefrigerant Chiller, E-234-003, on an as-needed basis, depending upon the leakage inthis system around the compressor seals, etc.

The circulating Propane Refrigerant exiting the Propane Refrigerant Accumulator, V-235-001, is sub-cooled in the Propane Refrigerant Subcooler, E-235-002, using theEthane Product as the coolant. The Propane Refrigerant is cooled from 118.4 OF (48OC) and 226.5 Psig (15.6 barg) to 112 OF (44 OC).

Propane Refrigerant is then routed to the Propane Product HP Refrigerant Cooler, E-233-004 A/B, and the Butane Product HP Refrigerant Cooler, E-233-006. Theremaining amount of the Propane Refrigerant is routed to the Propane RefrigerantCompressor HP Suction Drum, V-235-004. The Propane Refrigerant is adiabaticallyflashed to the drum pressure of 79 Psig (5.4 barg) producing a temperature of 51.3 OF(10.7 OC). In addition to this liquid refrigerant, the HP Propane Refrigerant returnvapour from the Propane Product HP Refrigerant Cooler and the Butane Product HPRefrigerant Cooler will join the flashed vapour and be routed to the PropaneRefrigerant Compressor, C-235-001 A/B.

The refrigerant liquid produced from the adiabatic flash in the Propane RefrigerantCompressor HP Suction Drum is routed to:

the Deethaniser Overhead Condenser, E-233-001, the Propane Product MP Refrigerant Cooler, E-234-001 A/B, the Butane Product Chiller, E-234-007, and the Deep Refrigerant Subcooler, E-235-012.

In addition, refrigerant liquid is routed to the Propane Refrigerant Compressor MPSuction Drum, V-235-003, and adiabatically flashed to the pressure of 26.8 Psig (1.8barg) and 5.4 OF (-14.8 OC). The vapour formed from the adiabatic flash along withthe combined vapour streams from the Deethaniser Overhead Condenser, thePropane Product MP Refrigerant Cooler, the Butane Product Chiller and the DeepRefrigerant Subcooler is routed to the Propane Refrigerant Compressor, C-235-001A/B.

The refrigerant liquid formed from the adiabatic flashing in the Propane RefrigerantCompressor MP Suction Drum is routed to the Dry Feed Gas Chiller, E-232-004 A/B.

PROCESS DESCRIPTION

Doc. No.:S090768.231-3.00-002-A-E

Job No.: 090768

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In addition, refrigerant liquid is routed to the Propane Refrigerant Compressor LPSuction Drum, V-235-002, and adiabatically flashed to the pressure of 5.5 Psig (0.4barg) and -27.2 OF (-32.9 OC). Refrigerant liquid formed in the Propane RefrigerantCompressor LP Suction Drum is used to chill the Propane Product in the PropaneProduct LP Refrigerant Cooler, E-234-002, and circulates through the shell-side of thisexchanger in a thermosiphon manner. The vapour formed from the vaporization ofthe refrigerant liquid in this drum along with the refrigerant vapour from the Dry FeedChiller is routed to the Propane Refrigerant Compressor, C-235-001 A/B.

These three streams comprise the feed streams to the Propane RefrigerantCompressor, C-235-001A/B which are compressed from 20.2 (15.7 Psia minimum)Psia to 41.5 Psia to 93.7 Psia and finally to 251.1 Psia. This combined refrigerantstream is cooled and condensed in the Propane Refrigerant Condenser, E-235-001A~H, with the liquid returned to the Propane Refrigerant Accumulator, V-235-001.

This completes the Propane Refrigeration Cycle.

NOTE: The Propane Refrigerant Compressor LP Suction Drum and the PropaneRefrigerant Compressor will be designed to accommodate a 1 Psig (0.07 barg) suctionpressure.

6.2 PFD: Refrigerant System (2/2) 090768.235-3.00-102-A-B

The Deep Refrigeration System is a closed-system that provides low temperaturechilling to the Propane Product Deep Refrigerant Chiller, E-234-003.

Because of the H2S content in the Ethane Product used for the make-up of this DeepRefrigerant, it has been decided to use essentially 99.9 % pure Ethane which will betrucked and stored at the plant for use when required, depending upon the leakage inthis system around the compressor seals, etc. The refrigerant composition will be:

C2 30.0000 % ETHANE 30 mol%C3= 70.0000 % PROPENE 70 mol%

Or

C2 37.0000 % ETHANE 37 mol%C3 63.0000 % PROPANE 63 mol%

The circulating Deep Refrigerant exiting the Deep Refrigerant Accumulator, V-235-011,is sub-cooled in the Deep Refrigerant Subcooler, E-235-012, using the MP PropaneRefrigerant as the coolant. The Deep Refrigerant is cooled from 118.4 OF (48 OC)and 424.7 Psig (29.3 barg) to 14.0 OF (-10 OC).

The Deep Refrigerant is then routed to the Propane Product Deep Refrigerant Chiller,E-234-003. The refrigerant vapour from the Propane Product Deep RefrigerantChiller is routed to the Deep Refrigerant Compressor Suction Drum, V-235-012. Therefrigerant vapour is adiabatically flashed to the drum pressure of 1.0 Psig (0.07 barg)producing a temperature of -55.4 OF (-48.6 OC). The flashed vapour is then routed to

PROCESS DESCRIPTION

Doc. No.:S090768.231-3.00-002-A-E

Job No.: 090768

Rev. B of 29

the Deep Refrigerant Compressor, C-235-011, where it is compressed to a pressure of159.4 Psig (10 barg) and a temperature of 167OF (75 OC) in the stage and a pressureof 434.7 Psig (30 barg) and a temperature of 234 OF (112.2 OC) in the discharge ofcompressor. The compressed refrigerant is cooled by the Deep Refrigerant Intercooler,E-235-013 and condensed in the Deep Refrigerant Condenser, E-235-011, usingSeawater as the coolant respectively. The condensed refrigerant liquid is returned tothe Deep Refrigerant Accumulator and this completes the Deep Refrigeration Cycle.

7. SOUR WATER STRIPPING (UNIT 236)

7.1 PFD: Sour Water Stripper System (1/2) 090768.236-3.00-101-A-B

The Sour Water Stripper System collects sour water from various sources in the planton an intermittent basis:

Feed Gas Separator, V-231-003 Feed gas Compressor Discharge Drum, V-231-005 A/B Regeneration Compressor Discharge Drum, V-231-007 Spent Regeneration Gas KO Drum, V-231-006 Dryer regeneration Compressor Suction Drum, V-231-008 Condensate Feed Drum, V-231-011 LPG Feed Drum, V-231-021 Sour Water from Slug Catcher Sour Water from Trains #1, #2, and #3

Sour Water from these various sources will be collected in the Sour Water FeedSeparator, V-236-002, where oil and hydrocarbons will be skimmed from the sourwater. The Slop Oil Pump, P-236-001 A/B, will remove any hydrocarbons collected inthe Separator and route them to the existing Blow Down system. The Sour WaterTransfer Pump, P-236-002 A/B, will transfer the Sour Water to the Sour Water Stripper,V-236-001.

The Sour Water Feed Separator is pressure controlled, with excess pressure beingrelieved to the Flare system and low pressure being increased by the import of LowPressure Fuel Gas (LPFG).

7.2 PFD: Sour Water Stripper System (2/2) 090768.236-3.00-102-A-B

The Sour Water Feed from the Sour Water Transfer Pump, P-236-002 A/B, routed theSour Water to the shell side of the Feed/Bottoms Exchanger, E-236-003 A/B, wherethe Sour Water Feed is heated from 104 OF (40 OC) to 208.4 OF (98 OC) beforeentering the Sour Water Stripper, V-236-001, on the top tray. The Sour Water Feedthen flashes producing an H2S rich overhead stream at 265 OF (129.4 OC).

The Sour Water Stripper overhead stream is partially condensed in the SWSOverhead Condenser, E-236-001, at a temperature of 149 OF (65 OC) and collected inthe SWS Reflux Separator, V-236-003. The vapour stream from the SWS Reflux

PROCESS DESCRIPTION

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Job No.: 090768

Rev. B of 29

Separator is routed to the existing Sulphur Recovery Unit at the Mina Al-AhmadiRefinery. The condensed liquid from the SWS Reflux Separator is pumped as refluxback to the top of the column by the SWS reflux Pump, P-236-004 A/B.

The SWS Reboiler, E-236-002, is a kettle-type exchanger and is provided to generatestripping steam within the column to strip out both H2S and CO2 from the strippedwater stream that eventually exits the bottom of the Sour Water Stripper. The SWSReboiler uses condensing LP Steam as the heating medium.

The stripped water exiting the bottom of the Sour Water Stripper is pumped by theStripped Water Pump, P-236-003 A/B, to the tube-side of the Feed/BottomsExchanger and then to the shell-side of the Stripped Water Trim Cooler, E-236-004A/B, and cooled to 100 OF (37.8 OC) and then to the Waste Water Treatment Plant,which is outside the battery limits of this project.

Drips and drabs of sour water collected from level instruments and valves and fromother sources will be collected in a closed-drain system and routed to a Sour WaterSump outside the plant’s battery limits.

PROCESS DESCRIPTION

Doc. No.:S090768.231-3.00-002-A-E

Job No.: 090768

Rev. B of 29


Figure 1: Feed Gas Dehydration

V-231-001A V-231-001B V-231-001C V-231-001D

74.6 bar-a74.6 bar-a 30.6 bar-a 30.1 bar-a

73.6 bar-g

F-231-003A/B

290 OCV-231-001A

74.6 bar-a

Feed Gas Dehydration

F-231-002A/B

F-231-004A/B

V-231-002

Dry Feed GasTo E-232-001 / 002

To V-231-012 A/BV-231-022 A/B

Dry Feed Gas

Spent Regeneration Gas (Cold)

To E-231-003

Regeneration Gas (Hot)

From H-231-002

Spent Regeneration Gas (Hot)

Regeneration Gas (Cold)

To E-231-004

From ERP HPFG

FC

Re-

Pre

ssur

ing

PROCESS DESCRIPTION

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Job No.: 090768

Rev. B of 29


Figure 2: Regeneration Gas Heater and Compressor

Spent Regeneration Gas (Hot)From V-231-001 A~E


Regeneration Gas (Hot)To V-231-001 A~E

Spent Regeneration Gas (Cold)From V-231-001 A~E

E-231-004

ERP HPFG

V-231-006366 Psig, 140 OF

HC Drain

Sour Water

E-231-003

H-231-002

HCD

SW

V-231-008

C-231-002

E-231-007 E-231-008

HPFG

LC

LC

LC

Regeneration Gas (Hot)To V-231-012 A/B

V-231-022 A/B

Regeneration Gas Heater & Compressor

From V-231-012 A/B & V-231-022 A/B

Spent Regeneration Gas (Hot) / (Cold)


To V-231-001 A~E

To V-231-012 A/B & V-231-022 A/B

HCD

HCD

PC

LPFG

PROCESS DESCRIPTION

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Job No.: 090768

Rev. B of 29

Figure 3: Condensate & LPG Dehydration

PROCESS DESCRIPTION

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Job No.: 090768

Rev. B of 29

Figure 4: Propane Treaters

PROCESS DESCRIPTION

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Job No.: 090768

Rev. B of 29

Figure 5: Butane Treater

process description

Documents

b page

choi b

feed pretreatment unit

product treating unit

feed gas dehydration

ngl recovery unit

lpg feed dehydration

feed gas compression