internship report on process of ppl

INTERNSHIP REPORT

PROCESS ENGINEERING DEARTMENT

PAKISTAN ETROLEUM LIMITED

PREPARED BY ABDUL MANAN MUGHAL

CLASS : B.E ( 3rd YEAR )

FROM DAWOOD UNIVERSITY OF ENGINEERING & TECHNOLOGY

SUBMITTED TO DR.SHUJJAT AHMED (MPrE)

Internship Report 2015

Prepared By :- Abdul Manan (DUET)

ACKNOWLEDGEMENT

I am student of 3rd year, department of chemical engineering, Dawood university of engineering

& Technlogy, are greatly thankful to ALMIGHTY ALLAH (who is the most Merciful & Beneficial) for having

the great opportunity to work in “Pakistan Petroleum Limited”, Karachi.

I Stay here in “Pakistan Petroleum Limited” (PPL) was no doubt, One of the most fruitful Period

of my life. My journey of merely one month could not have been completed is such a positive way

without the co-operation of “Dr Shujjat Ahmed (MPrE)” and “Mr Farooq Azam Shah (DCE Pr)”. and all

staff of “Process Engineering Department” Especially “Mr Imran Bukhari (EPr)” who in spite of being

busy with his duties, took time out of here, guide and keep me on the correct path.

I express my deepest thanks to “Sir Anas (Trainee Engineer)”, “Sir Athar Shaukat (AE Proc)” for

guidance and support. They helped me all time whenever I need during the whole period of my

internship.



Table Of Content

S.No Description Page

1 Gas Sweetening Unit

1.1 Amine system

1.2 PFD Of Amine System

1

2 Dew Point Control Unit (DPC)

2.1 Refrigeration

2.2 Dehydration Unit

2.3 PFD Of Refrigeration Unit

2.4 PFD Of Glycol Regeneration Unit

2.5 PFD Of Produce Water

3

3 HOT OIL HEATER SYSTEM 4

4 INSTRUMENT AIR SYSTEM 5

5 FIRE WATER SYSTEM 6

6 Storage & Loading Area 7

7 LABORATORY Testing

7.1 LPG Testing

7.2 Condensate Testing

7.3 Amine Testing

7.4 Glycol Testing

7.5 Produced water testing

9

8 Process Pipeline Colour Coding & Glossary of Terms 15

9 GLOSSARY OF TERMS 16



Gas Sweetening Unit (Amine system)

At Hala the process used for the sweetening is Amine Process with an aqueous solution of Methyl Di Ethanol Amine (MDEA) and Demineralised water (Demin water in short) with a concentration ratio of 45/55 respectively. This Amine plant is designed for 270 GPM (gal/min)

flow rate with one amine booster pump & one main amine charge pump running in series, with one pump as standby for both of them.

Sour gas from Inlet Separation unit enters the Amine Unit via Inlet Filter (28-VJ-100), which is a horizontal, two-section, high pressure vessel. Gas first enters in the section which contains Filter elements, and then to the other section through these filters elements. So any free liquid or solid particle is removed from the gas prior to its entry into the Contactor Tower 28-VB-200.

The Contactor is a tower with 20 Trays. The gas flows upwards through the contactor column with the amine solution flowing down the contactor over the trays from the top of the column. As the gas is leaving the contactor, the sweetened gas passes through a demister pad that reduces amine losses due to carryover in the gas path.

Sweet gas leaves the contactor and flows through a fin fan cooler and then through the amine after scrubber 28-VD-202 to recover any entrained amine solution. From here, the sweet gas flows into the Dew Point Control Plant.

In the Contactor, lean amine is continuously pumped to the upper section of the contactor, where it flows downward across each tray. As the lean amine flows downward, it absorbs acid gases from the rising sour gas.

Rich amine flows out from the bottom of the contactor and flows into the flash tank. The flash tank 28-VD-500 separates entrained gases and liquid hydrocarbons from the rich amine.

From the flash tank, the rich amine flows through particle, Hydro carbon and Post filters to the lean/rich heat exchanger. The warm rich amine then flows to the upper section of the still column (Stripper), cascading down the still column. The Still column is also a Tray Tower with 20 Trays. Lean amine in the bottom of the still is heated in the re-boiler. Some of the water in the amine solution vaporizes and rises up through the still and heats up the counter flowing rich amine. Acid gases are released and the excess vapour carries gases to the top of the still.

Excess vapour carries the released acid gases out the top of the still column to the reflux condenser 28-HC-506 and accumulator. Here the vapour is condensed and separated from the acid gases. The acid gases are removed from the system and the condensed liquid is pumped to the upper section of the still as reflux.



Heat is applied to the base of the still by Lean amine flowing through the re-boiler. Hot lean amine flows from the re-boiler base to booster pump suction and pumped through the lean/rich heat exchanger to preheat the rich amine flowing to the still. Lean Amine flows through Amine cooler to the Amine Surge Tank. Lean amine is stored in the surge tank until it is pumped to the upper section of the contactor by Amine Charge Pump.

Chemical Reaction:

R2CH3N + H2S → HS + R3NH+

R2CH3N + CO2 + H2O → HCO3- + R3NH+

REFRIGERATION UNIT

MDEA / GAS CONTACTOR

AM

IN

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FTER

S

CR

UB

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INLET FILTER

AMINE FLASH TANK

AMINE STILL COLUMN

AMINE BOOSTER PUMPS

AMINE CHARGE PUMPS

AMINE SURGE TANK

AMINE COOLER

GAS COOLER

REFLUX ACCUMULATOR

REFLUX PUMPS

AMINE REBOILER

AMINE RECLAIMER

SOLIDS FILTER

CARBON FILTER

SOLIDS FILTER

REFLUX COOLER

LEAN / RICH HEAT EXCHANGER

28FCV-5131

28LCV-2001

28LCV-2021

28

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28LCV-5081

28LCV-5001

Sales Gas

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Hot Oil Supply

Hot Oil Return

Hot Oil Supply

28-TCV-5081

28-TCV-5130

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Amine Plant Process Flow Diagram



Dew Point Control Plant (Refrigeration & Dehydration Unit)

The dew Point Control Plant (DPC) is designed & built by Startec Refrigeration, Calgary, Canada. This plant is built to treat 15 MMSCFD (Gas equivalent of HC Feed) to produce dry sales gas, LPG and NGL (condensate) as sales products. This plant works on the principle of “Compression Refrigeration”, that is, here the inlet gas is cooled in steps to condense the heavier ends (propane, butane, etc).

Sweet gas from downstream of the amine treatment plant that enters the DPC, is first cooled in two Gas/Gas Exchangers 28-HA-401 A&B, with the gas coming from Low Temperature separator (LTS). From here the gas goes to Gas/Liquids Exchanger 28-HA-401, where the gas is further cooled with the liquids coming from LTS. Finally the gas is chilled in Gas Chiller 28-HA-402. A Propane (R-290) refrigeration system provides cooling for the Gas Chiller.

For Gas Dehydration (and to prevent hydrate formation), a Glycol/Demineralised water mix is injected in tube side of Gas/Gas, Gas/Liquids and Chiller by two PD glycol injection pumps. Then this 3-phase flow (Gas, HC liquids, and Glycol/Demin water mix) is passed to the Low Temperature Separator (LTS), where all fluids are separated and take their individual paths for further processing.

Cold Gas from LTS passes back to shell side of both Gas/Gas exchangers, warmed up and leaves the DPC as Sales Gas. Sales gas temperature is controlled below 120 °F as a spec from SSGCL (customer). The sales gas specification for supply to SSGCL transmission line is strictly controlled in terms of Temperature, H2S, HC Dew Point and Water Dew Point.

Cold HC liquids pass to shell side of Gas/Liquids Exchanger, warm up by in coming gas stream and flow to De-ethaniser column (28-TE-501) via two small heat exchangers: Propane Sub cooler and De-ethaniser feed heater. De-ethaniser column (DC-2 in short) is a non-refluxed, distillation column, designed to remove most of the Ethane (C2H6) from the bottom product.

In the initial production case from upper basal, the top gas from DC-2 splits into two streams: one used as Fuel gas and the other goes to Recycle Gas Compressor and recycled back to plant inlet. In the final production case from lower basal, the top gas from DC-2 is used only as Fuel gas. In this case Recycle Gas compressor will be lined up with top gas from the Liquids Sweetening column 28-TE-200.

The DC-2 bottoms liquid goes to Debutanizer 28-TE-502 (DC-4 in short), which is a refluxed distillation column. DC-4 is designed to remove most of the Butanes from bottom product. The top product is fully condensed, pumped & then splits into two streams: Sales LPG & Reflux to DC-4. LPG passes to two storage bullets (one of 60 and one of 22 ton capacity). The bottoms Pentane rich liquid is sales condensate, which is cooled in the cooler and then flows to three condensate storage tanks (each of 1050 Barrels).



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HOT OIL HEATER SYSTEM

Various Reboilers and heat exchangers at Hala EPF use Hot Oil as a heating medium. The hot oil

is supplied from a gas fired Hot Oil Heater which is fueled from plant fuel gas.

Approximately 1500 GPM of hot oil is pumped around the hot oil loop by two pumps at a pump

discharge pressure of 65 PSI. The hot oil loop takes oil from the pump discharge directly to the

Amine system where significant heating is required and the oil then flows from the amine

system to the Refrigeration Plant for heating requirements in that system.

The hot oil heater has a design duty of 26.75 MMBTU/Hr and 16 MMBTU/Hr is required for the

Amine plant with the remaining duty required by the Refrigeration Plant.

The operating temperature of the hot oil heater is 475 °F and the feed loop of hot oil is

approximately 350 °F. The hot oil system also has filters and a surge vessel to provide pumps

suction in a closed loop system.



INSTRUMENT AIR SYSTEM

Instrument Air is used on the plant for the operation of:

I. Control valves, BDV’s, ESDV’s

II. Air-driven small pumps

III. Pneumatic controllers

IV. Cooling of some equipment

V. Starting system of Gas Gensets / Feed Gas compressor

A fully automatic Instrument Air Package provides IA to the plant. It contains two air compressors, one wet air receiver, one heat less air-dryer package consisting two dryers that operate in cycles, one dry air receiver and one start air receiver.

Compressors are designed for a flow rate of 121 Standard Ft3/min and 125 PSI pressure.

Normal pressure of IA is about 110 PSI throughout the plant. In case of very low pressure, a pressure switch 63-PSLL-1011 actuates an ESD.



FIRE WATER SYSTEM

To provide a passive fire protection & fire Extinguishing medium throughout the plant, a dedicated a Fire Water System exists. It includes one FW storage tank, one Electric jockey pump, two Diesel engine driven FW pumps with control panel, FW header, fire hydrants & monitors, a Deluge system for LPG bullets. There are two Bore holes with downhole pumps to fill the FW tank with fresh water as required.

The Jockey pump starts and stops automatically to maintain the FW header pressure between 70 & 138 PSI. Main FW pumps remain on AUTO mode; they start on Low FW header pressure, if the jockey pump cannot maintain its set point pressure. This would normally happen in the event of a fire for example, when a fire fighter has activated a fire hydrant and started to extinguish a fire. The resulting pressure drop from this action would activate the start sequence for the main fire water pump. Remaining data of FW system is given below:

Tank capacity: 10,000 Barrels

Tank Construction: Bolted Vessel type

Tank Inner Construction: Bladder type

Jockey Pump flow rate / pressure: 160 GPM / 200 PSI

Main FW flow rate / pressure: 1,663 GPM / 200 PSI

There are five fire monitors (WFM) and seven fire hydrants (WFH) at different locations of the

plant to provide fire extinguishing medium. Also, LPG storage tanks are provided with DELUGE

system to spray water throughout the tank surface to cool it. Deluge system can be actuated

manually or from HMI using control system.



Storage & Loading Area

Storage & loading area are divided in two sections: one for Condensate & one for LPG.

Condensate storage area contains three storage tanks with following data:

Tank capacity: 1050 BBLs each

Total site capacity: 3150 BBLs

Tank material: Carbon steel

All the tanks are atmospheric with 8 oz pressure & 176 °F design temperature. Each tank has isolation valves at inlet & outlet, so that any of the tanks can be lined up with the outlet of condensate to the loading stage. There are high and low level switches provided on each tank, to actuate ESD logic as required by the PCS. All the tanks are within a contained bund area to contain the condensate in case of any leakage from tanks and to avoid spillage out of that bunded area.

Condensate loading area contains two tanker loading pumps to load condensate in to customer’s tankers. Pumps data is given below:

Flow rate: 250 GPM

Pressure: 180 PSIg

Temperature: 122 °F

On the discharge line of each pump, there is a PD type flow meter, to meter the amount of condensate loaded to the tanker. Two tankers can be loaded at the same time with both pumps running and both flow meters in service. There is an earthing system provided for Tankers, so that either of the tankers currently being connected can be earthed. Earthing is required prior to start of loading to avoid any static charge produced during the loading operation. One diaphragm pump is also provided to load back from tanker to the storage tanks in case of any leakage from the tanker.

LPG storage area contains two storage tanks (called “Bullets”) with following data:

Tank capacities: 60 Metric Tonnes for the large bullet

22 Metric Tonnes for smaller bullet



Total site capacity: 82 Metric Tonnes

Tank material: Carbon steel

Max. Design Pressure: 250 PSIg

Max. Design Temperature: 165 °F

Both the tanks are of high pressure design, carbon steel tanks. Each tank has manual & automatic isolation valves at inlet & outlet, so that any of the tanks can be lined up with plant rundown of LPG. Two level transmitters and one sight glass are provided on each tank for level monitoring. There are high and low level trips provided on each tank, to actuate ESD logic as required by the PCS and CSS. Both the tanks are within a bunded area to contain the LPG, in case of any leakage from tanks and to avoid spillage out of that bunded area. Each bullet has high pressure control valve (PCV) to relieve excess pressure to flare in case of process upset. These PCVs also work as BDVs in case of an ESD to flare the tanks contents & lower their pressure to minimize risk of tank bursting or collapse.

LPG loading area contains two LPG loading pumps to load LPG in to customer’s tankers. Pump data is given below:

Flow rate: 175 GPM

Pressure: 250 PSI

Temperature: 200 °F

On the discharge line of each pump, there is a Coriolis type flow meter, to accurately meter the amount of LPG loaded to the tanker. These flow meters also communicate with control system for their running status, with high and low alarms and flow rate totalisers.

There is an earthing system provided for Tankers, so that the tanker being connected can be

earthed, prior to start of loading, to avoid any static charge produced during the loading

operation. Tanker earthing confirmation signal is inter locked with pump start permissive, so

that the pump does not start unless the earthing signal is confirmed on PLC.



LABORATORY FACILITY

Hala is one of the latest Analytical Equipped Laboratories in Pakistan. Our analytical work is performed in accordance with recognized standards such as ASTM, ISO and other accepted industry standards.

For good quality products and for our customer’s satisfaction we are using the latest analytical equipments.

We are doing LPG. Condensate, Amine, Glycol & produced water testing in this lab.

LPG

In LPG we are doing some important tests which are necessary for good quality LPG:

1- LPG Composition. 2- 95% Boiling Point (Weathering Test) 3- RVP. 4- Free Water 5- Copper Strip. 6- Mercaptan Sulphur.

1- LPG Composition:

For LPG composition we are using one of the latest LPG Gas Chromatograph

Reagents:

1- Helium Gas. 2- Calibration Gas.

Spec of LPG Composition is: C2: <1%, C3: 60%, C4: 40%, C5: <2%



2- 95% Boiling Point:

We are using approved method ASTM D-1837 for the volatility of LPG.

Spec of Weathering Test in LPG is: 35.96°F

3- RVP:

We are using Stanhope seta cylinder and pressure gauge to perform RVP test, approved

method ASTM D-1267.

Spec of RVP in LPG is: Min 70 PSIa and Max 200 PSIa

Stanhope-Seta Water Bath with Pressure Cylinders and Gauge.

4- Free Water:

For Free Water Test we are using Field Test Method.

Spec of Free water in LPG is: Nil

5- Corrosion Copper Strip:

For Copper Strip Test we are using method ASTM D-1838, this is one of the most important

tests in LPG and is also related to Sulfur in LPG.

Spec of copper strip is: 1



CONDENSATE

In condensate we are doing some important test as per our client demand like:

1- RVP

2- Sp. Gr.

3- BS&W

4- Salt

5- H2S

1- RVP:

RVP is one of the most important Test in Condensate and we are using one of the latest RVP

apparatus in this lab which is (8100-2 SETA Vap II), ASTM D5191 which is correlate with D323.

Spec of RVP in condensate is: <8 PSIa

8100-2 SETA VAP I

2- Specific Gravity:

This is simplest and also important test in condensate and we are using ASTM D1298 method.

We are using latest centrifuge machine in this Lab.



3- BS&W:

For BS&W test we are using (Benchmark 2000), approved method ASTM D-96. Reagents:

1- Toluene or Xylene. Spec of BS&W in condensate is: <0.05%

BENCHMARK 2000 4- Salt:

For salt test we are using Dual Extraction Apparatus (14300-3 Stanhope SETA) & and for titration Potentiometric Automatic Titrator (AT-500N), approved method ASTM D 6470. Reagents & Materials:

1- Acetone (2-propanone). 2- Alcohol. 3- Barium Nitrate. 4- Hydrochloric Acid, 0.1 mol/L. 5- Nitric acid, 0.5 mol/L. 6- Silver Nitrate Solution. 0.1 & 0.01 mol/L. 7- Sodium Chloride Solution. 8- Xylene. 9- Lead Acetate Paper. 10- Polishing Paper.

Spec of Salt in condensate is: 6lbs/1000bbl.



5- H2S:

For the detection of H2S we are using Doctor Test and for the quantity of H2S in condensate we use method IP103. Reagents:

1- Cadmium Sulfate Solution. 2- Sodium Thiosulphate solution, 0.1N. 3- Starch Solution, 0.5%. 4- Hydrochloric Acid. 5- Doctor Solution.

Spec of H2S in condensate is: < 2ppm

AMINE

1- Concentration of amine, Field Test Method.

Reagents:

1- Hydrochloric Acid, 0.5N.

2- Methyl Purple or BromoPhenol Blue Indicator.

2- H2S Loading approved Method UOP-827.

Reagents:

1- Sodium Thiosulphate solution, 0.1N. 2- Starch Solution, 0.5%. 3- Hydrochloric Acid. 4- Iodine, 0.1N.

3- CO2 Loading approved Method UOP-829.

CO2 Loading is determined by difference.

4- Acid gas loading,

Reagents:

5- Methanol. 6- KOH, 0.5N. 7- Thymophthalene Indicator.



GLYCOL

Purity of Lean and Rich Glycol by Karl Fischer Moisture Titrator (MKC-501).

Reagents:

1- Anolyte (Electrolyte AG). 2- Catholyte (Electrolyte CG).

Produced Water

1- Chloride, Method# ASTM-D512.

Reagents:

1- AgNO3

2- Potassium Chromate.

2- pH, Method# ASTM D1293.

Reagents:

1- Buffer Solutions of 4, 7, 9, 10



Process Pipeline Colour Coding & Glossary of Terms

STANDARDISED COLOUR CODING OF PROCESS PIPELINES

SERVICE STREAM PIPING COLOUR

RAW / SWEET / SALES GAS YELLOW

INSTRUMENT AIR DARK BLUE

RAW / DEMINERALISED / COOLING WATER LIGHT BLUE

FIRE WATER RED

FIRE FIGHT FOAM YELLOWISH CREAM

TEG / MEA / MDEA / (LEAN) ORANGE

TEG / MEA / MDEA / (RICH) GREEN

CONDENSATE / HC LIQUIDS BROWN

STEAM SILVER

ACIDS / ALKALIES VIOLET



GLOSSARY OF TERMS

PD Meter Positive Displacement Flow Meter

PSIa Pounds per Square Inch Absolute

PSIg Pounds per Square Inch Gauge

HC Hydro-Carbon

BOM Build, Operate, Maintain

P&ID Piping & Instrumentation Drawing

PFD Process Flow Drawing

PPM Parts per Million

WFM Water Fire Main

CSS Control System Shutdown

UPS Uninterrupted Power Supply

ESD Emergency Shutdown

PCS Process Control System

PSD Process Shutdown

BBLs Barrels

GPM Gallons per minute

PID Proportional, Integral, Derivative (Control Blocks)

PLC Programmable Logic Controller

HMI Human Machine Interface

PCV Pressure Control Valve

Bund This is a spillage containment area around storage vessels

LPG Liquified Petroleum Gas

NGL Natural Gas Liquids

Hz Hertz (Frequency)



kVA kilo Volt Amps

kW kilo Watts

RPM Revolutions per minute

DPC Dew point control

BDV Blowdown Valve

EPF Early Production Facility

DC-2 De-Ethaniser Column

DC-4 De-Butaniser Column

LTS Low Temperature Separator

FG Fuel Gas

PRV Pressure Regulating Valve

internship report on process of ppl

Documents

amine unit

amine testing

amine process

pfd of amine system

amine losses

amine plant

gas path

amine booster pump