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0 07/06/2010 ISSUED FOR CONSTRUCTION ER CGT JA AM

E 20/05/2010 ISSUED FOR REVIEW AND APPROVAL ER CGT JA AM

D 15/03/2010 ISSUED FOR REVIEW AND APPROVAL ER CGT JA AM

C 10-02-2010 RE-ISSUED FOR HAZOP ER CGT JA AM

B 21-01-2010 ISSUED FOR HAZOP ER CGT JA AM

A 15-12-2009 ISSUED FOR REVIEW AND COMMENTS ER CGT JA AM

REV. DATE DESCRIPTIONBY CHKD APPD APPD.

TECNOCONSULT TOLEDO

Client RUWAIS REFINERY (TAKREER)

Project ADDITION OF LPG DEHYDRATION UNIT AT RUWAIS REFINERY

Title OPERATION, CONTROL AND INTEGRATION PHILOSOPHY

FEED Doc. No.: 6132-116-02-41-OCP-01 Doc. No: 5821-116-PA-E-00002 Rev 0 sheet: 1 of: 12

AGREEMENT No. 06RREDR10331

ADDITION OF LPGDEHYDRATION UNITAT

RUWAIS REFINERY

OPERATION,CONTROL AND INTEGRATION PHILOSOPHY

FOR

LPGDEHYDRATION UNIT 116

APPROVED FOR CONSTRUCTIONIMPLEMENTATION VIA TAKREER EMAIL

DATED 07-06-2010REF. NO T1149-DT-0843 DATED 23-05-10

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FEED Doc No.: 6132-116-02-41-OCP-01 Doc No.: 5821-116-PA-E-00002 Rev 0 Sheet 2 of: 12

REVISION DESCRIPTION SHEET

REV. DATE PARA. REVISION DESCRIPTION

A 15-12-2009 ALL ISSUED FOR REVIEW AND COMMENTS

B 18-01-2010 ALL ISSUED FOR HAZOP. INCLUDED NEW

OPERATION CONTROL SCHEME. REMOVEDVALVES 116-HV-110 AND 116-HV-111.ADDED CONTROL VALVE 116-PCV-100 INTHE LINE 6-116-P101-31051W-V

C 10-02-2010 ALL RE-ISSUED FOR HAZOP. INCLUDED NEWOPERATION CONTROL SCHEME. ADDEDVALVES 116-HV-110 AND 116-HV-111.ADDED CONTROL VALVE 116-FV-100 AND116-102 IN THE LINES 6-116-P100 AND 6-116-P101 RESPECTIVELY.

D 14/03/2010 ALL ISSUED FOR REVIEW AND APPROVAL

E 20/05/2010 ALL ISSUED FOR REVIEW AND APPROVAL

0 07/06/2010 ALL ISSUED FOR CONSTRUCTION

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HOLDS DESCRIPTION SHEET

REV. DATE PARAGRAPH REVISION DESCRIPTION

A 15-12-2009 NONE ISSUED FOR REVIEW AND COMMENTS

B 18-01-2010 NONE ISSUED FOR HAZOP INCLUDED NEWOPERATION CONTROL SCHEME.REMOVED VALVES 116-HV-110 AND 116-HV-111. ADDED CONTROL VALVE 116-PCV-100 IN THE LINE 6-116-P101-31051W-V

C 10-02-2010 NONE RE-ISSUED FOR HAZOP. INCLUDED NEWOPERATION CONTROL SCHEME. ADDEDVALVES 116-HV-110 AND 116-HV-111.ADDED CONTROL VALVE 116-FV-100 AND116-102 IN THE LINES 6-116-P100 AND 6-116-P101 RESPECTIVELY.

D 14/03/2010 NONE ISSUED FOR REVIEW AND APPROVAL

E 20/05/2010 NONE ISSUED FOR REVIEW AND APPROVAL

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TABLE OF CONTENTS

1.0 INTRODUCTION .............................................................................................. 51.1 BACKGROUND .................................................................................... 51.2 PURPOSE ............................................................................................ 51.3 REFERENCE DOCUMENTS ................................................................ 5

2.0 OVERVIEW OF EXISTING UNITS AND PROPOSED NEW UNIT .................. 52.1 EXISTING UNIT- 216 ............................................................................ 52.2 EXISTING UNIT- 112 ............................................................................ 52.3 NEW UNIT 116 .................................................................................. 5

3.0 OPERATING AND CONTROL OBJECTIVES FOR U-116 .............................. 64.0 OPERATING AND CONTROL PHILOSOPHY FOR U-116 ............................. 65.0 INTEGRATION WITH EXISTING FACILITIES ............................................... 11

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1.0 INTRODUCTION

1.1 BACKGROUND

Abu Dhabi Oil Refining Company, TAKREER, operates and maintains Ruwais RefineryComplex in Ruwais.

There are two LPG dehydration units, Unit-216 for drying LPG from CondensateProcessing trains and another Unit-112 for drying LPG from Naphtha Hydrotreating unit,Catalytic Reforming unit and Hydrocracking unit. Whenever these Dehydration units areout of service while the LPG is produced from upstream units, LPG has to be routed toeither fuel gas or flare.

It is intended to install new LPG dehydration unit which will act as common standby forthe existing dehydration units.

For reference see Operating, Control and Integration Philosophy 6132-116-02-41-OCP-01 Rev.1

1.2 PURPOSE

The purpose of this document is to provide operating and control philosophy for theStandby LPG Dehydration Unit 116.

1.3 REFERENCE DOCUMENTS

Design Basis Memorandum - LPG Dehydration Unit at Ruwais Project. Doc. No. 5821-116-GA-E-00001.

P&ID, Piping and Instrumentation Diagram LPG Dehydration Unit-116. Doc. No. 5821-116-GD-C-001,

ESD Cause and Effect Diagram Doc. No. 5821-116-SB-B-00013

ESD Narratives Doc. No. 5821-116-SA-E-00301

2.0 OVERVIEW OF EXISTING UNITS AND PROPOSED NEW UNIT

2.1 EXISTING UNIT- 216

LPG from the two condensate trains is dehydrated in U-216. The capacity of this unit is800 MT/day. This LPG Dehydration unit utilizes molecular sieve adsorbents. LPGbooster pumps are provided.

2.2 EXISTING UNIT- 112

Dehydration unit U-112 receives LPG produced from Naphtha Hydrotreating, CatalyticReforming unit and Hydrocracking unit. The capacity of this unit is 820 MT/day. This

LPG Dehydration unit utilizes molecular sieve adsorbents.

2.3 NEW UNIT 116

New dehydration unit (U-116) will act as common standby to existing units, U-216 andU-112. The new unit will receive wet LPG from U-216 feed as well as U-112 feed. Thecapacity of this new unit will be 820 MT/day with a 20% design margin. New unit will be

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located near existing unit 112 (at about 150 m). Wet LPG feed line of about 1.3 km willbe provided from U-216 to the new unit location and about 150 m will be provided fromU-112 to new unit location.

3.0 OPERATING AND CONTROL OBJECTIVES FOR U-116

The unit U-116 is intended to serve as a standby to existing units, U-216 and U-112.This unit can receive wet LPG from U-216 feed as well as U-112 feed.

The unit is designed to operate

Independently at 100% capacity with either U-216 LPG feed or U-112 LPG feed.

By sharing feed with existing unit at 50% capacity with either U-216 or U-112feed.

The unit can also process mixed feed (U-216 feed & U-112 feed) at any capacityfrom its turndown to full capacity.

Since, the unit-116 will normally operate in parallel with existing units, it is important tocontrol the feed flow rates to the new and existing units, in order to ensure the desired

distribution of feed flow rates.

4.0 OPERATING AND CONTROL PHILOSOPHY FOR U-116

Feed Receipt

The wet LPG from unit-216 feed is received at about 21.5 22.5 kg/cm2g and 45 C, in a

6-116-P100-31051W-V from existing U-216, which is located at about 1300 m distancefrom U-116. The wet LPG from unit-112 feed is received at 23- 24 kg/cm

2g and 25C

45C, through a 6-116-P101-31051W-V , from existing U-112, which is located at about150 m distance from U-116. Battery limit isolation valves (double block) along with anon-return valve are provided on both these feed lines. Both these lines join thecommon 6 feed header, which feeds the wet LPG to the Dehydration Package, 116-ME-001. See P&ID 5821-GD-C-00001

In order to achieve the hydraulic balance during the sharing feed operation scheme, flowcontrol stations 116-FV-100 and 116-FV-102 are installed at feed lines from U-216 andU-112 respectively. In the case of sharing feed operation the operator will reset the flowset point to the percentage required.

The wet LPG flow is measured by 116 - FE/FT- 100 / 102 located at feed lines from unit-216 and unit 112 respectively. When the unit U-116 is sharing feed along with theexisting units U-216 / U-112, then the flow is to be diverted through the control valve,116-FV-100 and 116-FV-102 located in the feed lines. This is to ensure control of theflow as required for processing in the existing as well as in the standby unit. When theunit 116 is operating at 100% throughput, the LPG will be routed through control valve116-FV-100 (if flow is coming from unit 216) or 116-FV-102 (if flow is coming from unit112).

Sharing feed in the Unit 116 with existing Unit 216 shall be avoided in case of transfer toOil Movement operation. In order to ensure this operation the interlock I2 will close theflow control valve 116-FV-100 when the flow value in the transmitter 207-FT-001 and216-FT-110 is different than zero (0).

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The feed pressure and temperature are also measured. Alarms provided for high andlow feed flow rates, high and low feed pressure and for high feed temperature.

Operation of LPG Dehydration Package, 116-ME-001

The dehydration package is designed to operate continuously. Two dryer towers areprovided - one will be under drying cycle and another in regeneration cycle. Thedehydration package is based on molecular sieve adsorbents. The package includesclosed regeneration system using dry product LPG for regeneration.

Drying Operation

The drying section comprises of feed Coalescer (116-ME-001D1), Dryer towers (116-ME-001D2A/B) and After-filters (116-ME-001V1A/B).

The free water in LPG feed is first removed in feed Coalescer and further dehydration iscarried out in LPG Dryer to remove saturated water. The dried LPG is routed throughAfter-filter; where any carryover of adsorbent particles are filtered from the product dryLPG.

One Feed Coalescer is provided, 116-ME-001D1. The pressure at inlet of feedcoalescer and pressure drop across the feed coalescer are measured, 116-PT-200 and116-PT-202.

The water accumulated in the coalescer is routed to sour water header based on levelcontrol. High level alarm is also provided.

Two Dryers are provided, 116-ME-001D2A/B, one of which will be in drying mode andanother will be in regeneration/ standby mode. The dryer beds are designed for anAdsorption cycle time of 8 hours at the design capacity. The feed enters from the bottomand exits from the top of the dryer tower.

Two after filters are provided, 116-ME-001V1A/B, one under operation and another isstandby. Standby is provided to facilitate internals maintenance and replacement whenthe package unit is under operation. Pressure drop across the after filter is measuredand change over of after filter is effected based on high pressure drop alarm.

Moisture analyzer is provided, 116-AE-200, on dry LPG product line.

The pressure and temperature of dry LPG product at outlet of after filter are alsomeasured.

Safety relief valves are provided for each one of the following equipment: coalescer,dryer tower and after filter vessels. These are provided to protect the individual vesselsfrom pressure build up due to heat input from external fire.

Instrumented Protective Function

On low-low interface level in feed coalescer, the sour water outlet will be closed. This is

to avoid LPG ingress in to sour water system.

The valve 116-LXV-201 shall be close when the level transmitter 116-LT-201 set low-lowlevel alarm. All signal associated to valve 116-LXV-201 and level transmitter 116-LT-201shall be integrated in the ESD system.

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Regeneration Operation

The regeneration section comprises of Regeneration pumps, 116-ME-001G1A/B, LPGVaporiser,116-ME-001E2, LPG Superheater ,116-ME-001E3, Cooler/Condenser, 116-ME-001E4 A/B.

When the dryer bed in operation is saturated with water, the feed LPG is to be divertedto the other dryer bed, which is in standby mode. The saturated dryer bed has to beregenerated.

The regeneration operation sequence involves displacement of LPG liquid from dryertower back in to the feed line upstream of the coalescer, heating of the dryer bed withvaporized regeneration stream for desorption of water, cooling of the dryer bed andfilling of the dryer with dry LPG liquid. Once the bed is regenerated, it is maintained onstandby mode, which is ready for changeover for drying operation.

The heating operation is carried out counter-current to feed flow during drying operation.That is, during heating, the regeneration stream enters from top and exits from bottom ofthe dryer tower. The cooling/filling operation is carried out co-current to feed flow duringdrying operation. That is, during cooling/filling, the stream enters from bottom and exitsfrom top of the dryer tower.

Instrument Protective Function

On high-high temperature in the LPG super heater or high-high temperature in theRegeneration Separator the medium pressure steam inlet will be closed. This is toavoid medium pressure ingress into LPG super heater.

The valve 116-TV-104 shall close for high-high temperature in the LPG Super Heateroutlet when 116-TAHH-208 alarm is activated or high-high temperature in theregeneration separator 116-TAHH-203 alarm is activated. Signals associated to 116-TV-204, 116-TT-203 AND 116-TT-208 shall be integrated in the DCS system.

On low-low level in the Regeneration Separator, the Oily Sewer outlet shall beclosed.

The valve 116-LXV-210 shall close for low-low level in the Regeneration Separator when161-LALL-101 alarm is activated. Signals associated to valve 116-LXV-210 andtemperature transmitter 116-LT-210 shall be integrated in the ESD system.

The regeneration Pumps 116-ME-001G1A/B shall stop for the following causes:

On low-low flow at the pumps discharge, 116-FALL-201 alarm and Pumps Trip will beactivated; this action is performed by the DCS logic with action over the MCC.

On High-high temperature at the Regeneration Separator when 116-TAHH-208 alarm isactivated, this action is performed by the DCS logic with action over the MCC.

On/Off switching valves commands are accessible to operator from DCS Systemonly when the sequence is stopped and is in Manual mode.

Valve Failure alarm is activated when any on/off automatic valve position is notconsistent with valve desired status (depending on actual sequence phase). WhenVave Failure alarm is activated the sequence is put on Hold, if the alarm causereenters, the sequence is automatically restarted (even if alarm has not been yetacknowledged).

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Valve Failure time out has been set to 60 seconds fixed value for all valves. (SeeFunctional Description 3014-02BD07.01-01).

Heating Cycle

The regeneration of dryer beds is carried out using a slip stream from dried LPG productwhich is pumped using regeneration pumps, 116-ME-001G1A/B. One pump will beunder operation and another will be standby. Flow controller, 116-FV-200, is provided atdownstream of the regeneration pumps, to control the flow rate of regeneration stream.

This pumped stream is routed to LPG Vaporizer 116-ME-001E2, the heating medium isLow Pressure Steam (LPS). This vapour is routed to the dryer bed under regeneration,through the LPG superheater 116-ME-001E3; the heating medium is Medium PressureSteam (MPS). The temperature at the superheater outlet is ramped up during theheating cycle. In both heat exchangers the outlet streams for the heating side is lowpressure condensate and will flow through Condensate Recovery Pot, 116-ME-001D3steam traps to the LP condensate header.

Temperature controller is provided at the outlet of super heater and level controller isprovided in vaporizer both modulate the incoming steam flow to the respective HX.

The superheated vapour desorbs the water from the saturated bed and exits from thebottom. Temperature indication and high alarm are provided at the outlet of dryer bed.

Cooling Cycle

Once adsorbed water from the dryer bed is removed, heating cycle is completed andthis is to be followed by cooling / filling cycle.

During the cooling / filling cycle, the slip stream from dried LPG product is pumped to thedryer tower from bottom and the displaced stream from the top of dryer is routed tocooler/condenser and sub-cooler, where it is cooled. This cooled stream joins the feedLPG stream upstream of the Coalescer.

Standby Mode

Once the cooling and filling cycle is completed, the regeneration pump is switched offand dryer bed is isolated from regeneration circuit and kept on standby mode, whichmeans it is ready for lining up for drying cycle.

Automati on of Dryer bed Changeover and Regeneration operat ion

Dryer bed changeover and regeneration operation can be carried out automaticallyusing the sequencing logic controller, by automatic sequencing and timing of valveoperations. However, provision for manual operation overriding automatic operation,during any of the sequencing step will be provided. The operational sequence for logic isbriefly explained below.

The dryer bed change over can be after 8 hours of adsorption. Alternatively, changeover can be initiated based on bed saturation sensed by analyzer provided on the driedLPG line. The changeover sequencing will involve checking of availability of the otherdryer on standby mode. If found so, the valves in drying circuit for the standby dryer willbe opened thus establishing flow through the standby dryer. This is followed by isolatingthe saturated dryer from the drying circuit by closure of relevant valves. This completesthe changeover sequence.

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Changeover sequence is followed by regeneration sequence. Under regeneratingsequence, heaters and pumps are checked for availability, the relevant valves in theregeneration circuit are opened. The available pump (selected and specified byoperator, if any of the pumps is under maintenance) is started and the vaporizer outlettemperature set point is specified. As per the pre-specified time sequencing, thevaporizer and superheater outlet temperature is gradually increased (ramped up) andmaintained for pre-specified time (in order to complete regeneration of the dryer bed).

At the end of heating period the adsorbent bed will be completely regenerated. Onreaching these conditions, the heater shall be switched off and bed is cooled by productLPG.

After cooling the regenerated adsorber remain in stand by.

The complete details will be provided by vendor ISG in the operating manual.

LPG Booster Pumps, 116-G-001A/B

When the unit U-116 is operating with unit U-216 feed which is at about 21 kg/cm2g at

the unit inlet, the product LPG is to be pumped to the GASCO header at a requiredheader pressure of 18.5 19.5 kg/cm

2g (at the Tie-in location). Two pumps are provided

with capacity of each pump being 50% of design capacity of the unit U-116.

When the unit U-116 is operating with unit-112 feed which is at about 23 kg/cm2g at the

unit inlet, the product LPG can be routed to the GASCO header bypassing the pumps.However, in case the feed pressure is less, the pumps can be used. See P&ID 5821-116-GD-C-00001

Instrumented Protective Function

When there is no feed flow to the unit, the operating pumps will be stopped.

The LPG Booster Pumps 116-G-001A/B shall stop when the flow in the inlet line is lessthan 15.5 m3/h. The action trip for the LPG Booster Pumps 116-G-001 A/B for low-lowflow in the inlet feed of the LPG Dehydration Unit is performed by the DCS Logic withaction in the MCC.

One flow transmitter ,116-FT-100 is installed in the line 6-116-P100-31051W-V to checkthe flow from the Unit 216 to Unit 116 and another one 116-FT-102, is provided in theline 6-116-P101-31051W-V to monitor the feed flow from the Unit 112 to Unit 116.

These flow signals shall be implemented in the DCS system and integrated in theinterlock I1 for generate low-low flow alarm on DCS and send one stop command signalof LPG Booster Pumps 116-G-001 A/B from DCS to MCC

Emergency Shutdown

Emergency Shutdown valve, 116-HXV-101 is provided on LPG line from dehydrationpackage at upstream of booster pumps in order to stop feeding a fire case of pumpleakage.

Signals associated with the valve 116-HXV-101, like open and close limit switch 116-HZSO-101 / 116-HZSC-101, local pushbutton for close and open valve 116-HXPB-101A/ 116-HXPB-101B, solenoid valve 116-HY-101, remote pushbutton for close the valve

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116-HXPB-101C and command signal for stop the pump when the valve is closed shallbe implemented in the ESD System

The LPG booster pumps 116-G-001-A/B pumps shall trip when the operator manually orremotely closes the valve 116-HXV-101. See ESD Cause and Effect Diagram Doc. No.5821-116-SB-B-00013 and ESD Narratives Doc. No. 5821-116-SA-E-00301.

Product Dispatch

The dry LPG product flow is measured using Coriolis mass flow meter, 116-FI-101, andprovision to route the LPG to GASCO headers are provided. The product is routed to thedestination based on back pressure at unit U-116 outlet control.

The sour water from the unit is routed to the existing sour water stripper unit through tie-in to the existing header.

5.0 INTEGRATION WITH EXISTING FACILITIES

The unit U-116 is standby unit for existing units U-216 and U-112 and will be integratedwith existing facilities for the following

Feed tie-in

Product tie-in

Flare connection

Utility connection

Feed Tie-in

The wet LPG from unit-216 feed is tapped from the U-216 feed line and is received in a6 line at U-116. The wet LPG from unit-112 feed is tapped from the U-112 feed line andis received through a 6 line. At unit 116, battery limit isolation valves (double block)along with a non-return valve are provided on both these feed lines.

When the unit U-116 is sharing feed along with the existing units U-216 or U-112, thenthe flow is to be diverted through the control valves 116-FV-100 and 116-FV-102 in thenew U-116. This is to ensure control of the flow as required for processing in the existingas well as in the standby unit. For this purpose, On/Off valves are also provided in theexisting units 216 and 112 (HV-110 for U-216 and HV-111 for U-112).

Product Tie-in

Connections provided to route the LPG to both the GASCO headers, to which productfrom U-112 and 216 are routed.

The sour water from the unit is routed to the existing sour water stripper unit through tie-in to the existing header.

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FEED D N 6132 116 02 41 OCP 01 D N 5821 116 PA E 00002 R 0 Sh t 12 f 12

Flare Connection

Flare header from this unit is connected to hydroskimmer unit flare header and toCondensate processing unit flare header. This is to ensure availability of the standbyunit U-116 during shutdown of either of the units, U-216 or U-112.

That is, when the condensate processing unit and associated facilities are undershutdown, then this unit will be required as standby for U-216 and in such scenario, theflare connection with condensate processing unit will be isolated and connection withhydroskimmer unit will be utilized and viceversa.

The flare connections are provided with isolation valves key tapping to facilitate the flowalignment to Hydroskimmer and Condensate flares in use and block the other one.The relief load to Condensate flare will be used only when there is a general shutdownin Hydroskimer Flare. One Drain Pot 116-D-001 is provided with steam out and steamtrace. Outlet lines to the condensate header shall be heat-traced from Drain Pot 116-D-001 to the highest point of the condensate flare header.

Utilities

Utility required for this unit are fresh cooling water, Medium Pressure Steam, LowPressure Steam, power and instrument air for continuous consumption. Nitrogen isrequired for purging and maintenance purposes. Service air, LPS and utility water arerequired for hose station.

The required utilities are tapped from the headers available in the location of the unit U-116.

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