RAG Utilization & Flare Mitigation Project

In NGL Plant Complexof Qatar PetroleumA Successful Story of 

An Environmental Friendly Process

Prepared and Presented By

Senior Planning Engineer (Production)

Ghareb Al‐Mahmoud

Outline

• Global Worming Effect

• The NGL Plants Complex Facilities

• RAG & Flare Mitigation Project– Objectives– Description– Benefits

• Conclusion

Solar radiation in the form of light waves passes through the atmosphere

Most of this radiation is absorbed by the earth and warms it up

Some energy is radiated back into space by the earth in the form of infrared waves

Some of this outgoing infrared radiation is trapped by the earths atmosphere and warms it

As this layer get thickened, more radiated waves is trapped within the air atmosphere raising the earths temperature

Qatar PetroleumNGL Plant Complex

`PS-3

MAYDANMAHZAN

BUL-HANINE

HALUL

PS-2

PS-1

AL-BUNDUQ

IDDAL-SHARGI

DOHA

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WAKRAH

NORTH FIELD

RAS LAFFAN

AL-KHOR

RICH  GAS

LIQUID

OIL

LEAN  GAS

DUKHAN

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Slide 6

Q1 QPUser, 31/Oct/08

The NGL Plants Complex

NGL‐2

NGL‐1

NGL‐3

NGL‐4

FSP OnShoreNGL

ARAB –D NGL

Inj. Station

Off‐Shore Sour 

AccociatedGas

North Field Alpha

ALS  Rich Associated 

Gas

QatarGas& RasGas

Sour Fuel Gas

Industries

Power StationsLean Fuel 

Gas

Ethane Petrochemical Plants

Butane

NGL Condensate

Naphtha (NFC)

Propane

EXPORT

Naphtha (DSC)

Local Supply

To Refinery or Export

Molten Sulphur

Local Supply

NGL ‐ 11980 ‐ NGL‐1 Fractionation & Treating plant commissioned. 

NGL ‐ 1

FSP De‐C2

Ethane

De‐C3

ADIP  MEROXMolseieveAdsorber Chilling

MEROXMolseieveAdsorber

De‐C4

Cooling MEROX NGL Cond. To Storage

LPG ex QPR (CR)

C3+ ex ERU

LPG ex QPR (ST)

LPG ex QPR (CR)

C3 to Storage

Boil‐off Recovery

Chilling C4 to Storage

Boil‐off Recovery

RVP Correction 

unit

Light Pentane

NGL ‐ 21980 ‐ NGL‐2 Fractionation & Treating plant commissioned.

NGL ‐ 2

De‐C2

Ethane

De‐C3

ADIP MolseieveAdsorber Chilling

MolseieveAdsorber

De‐C4

CoolingNGL 

Cond. To Storage

C3+ ex ERU

LPG ex QPR (CR)

LPG ex QPR (CR)

C3 to Storage

Boil‐off Recovery

Chilling C4 to Storage

Boil‐off Recovery

De‐C1

Off‐Shore Gas 24”line

Stripping Unit

Sour Fuel GasSour 

Fuel Gas

FSP

NGL ‐ 3

1991 ‐ NGL‐3 plant commissioned.

NGL ‐ 3

34”North 

Field Gas Line

Gas Reception unit

Molesieve

AGR GDH

NGL Extraction

Lean Gas to 

Industries

Lean Gas to 

PowerPlants

Gas to Fahahil Re‐Injection

Raw NGL to NGL‐1

Sour Gas Compressor

Raw NGL to NGL‐4

12” North Field 

Condensate

Line

Condensate Reception

Stabilizer unit (6112)

NF Stabilized Condensate

NFC to Refinery/ Export

Sour Gas unit (6112)

NGL ‐ 42002 ‐ NGL‐4 plant commissioned.

NGL ‐ 4

ARAB‐D

NGL‐3 Raw NGL

De‐C2

Ethane

De‐C3

De‐C4

De‐C3

De‐C4

De‐C2

Ethane

ADIP  MEROXMolseieve Adsorber

Propane toChilling and Storage

MEROXMolseieve Adsorber

Butane to Chilling and Storage

Cooling MEROX NGL Cond. To Storage

RAG Utilization & Flare Mitigation Project

The Objectives of the RAG & Flare Mitigation Project

• Mitigate flaring emissions ( ERG, Liquids…)

• Maximize gas/liquid hydrocarbon recoveries from burning streams

• Eliminate ground level burn pits

• Improve the combustion performance of the flaring facilities 

Al‐Shaheen Rich Associated Gas (RAG) Utilization

Al‐Shaheen Field’s RAG Utilization

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MAYDANMAHZAN

BUL-HANINE

HALUL

PS-2

PS-1

AL-BUNDUQ

IDDAL-SHARGI

DOHA

MESAIEED

WAKRAH

NORTH FIELD

RAS LAFFAN

AL-KHOR

RICH  GAS

LIQUID

OIL

LEAN  GAS

DUKHAN

ALSHAHEEN

Al‐Shaheen Field’s RAG Utilization

• Optimize Al‐Shaheen rich associate gas (RAG) utilization

• Being a heavier gas, it requires a heaver cooling/heating duties

• Modify NGL‐3 Extraction Unit to be able to process Al‐Shaheen gas

Al‐Shaheen Field’s RAG Utilization• RAG Utilisation itself reduces the emission load as per the table below:

Emission GasComponent

Emission factor, tonne/tonne gas burned*

Emission reduction,tonnes/day

CO2 2.61 11740

CO 0.0087 39

NOx 0.0015 7

SO2 0.02 90

CH4 0.035 157

VOC 0.015 67

Total - 12100

** Based on the maximum sulphur content of 0.35 mol%

Flare Mitigation at the NGL Plants Complex

• Ethane Rich Gas (ERG) Recovery

• Hydrocarbon Recovery From Burning Streams

• Flare Modification

Ethane Gas Recovery

• Ethane Rich Gas is Supplied as a Feed Stock to Petrochemical Plants

• Flare Mitigation Project Provided an Ethane Compressor to Cater for Ethane Injection During Consumer Limitations or Plant Upsets

Ethane Gas Recovery

34”North 

Field Gas Line

Gas Reception unit

Molesieve

AGR GDH

NGL Extraction

Lean Gas to 

IndustriesLean Gas 

to Power Plants

Gas to Fahahil Re‐Injection

Raw NGL to NGL‐1

Sour Gas Compressor

Raw NGL to NGL‐4

12” North Field 

Condensate

Line

Condensate Reception

Stabilizer unit (6112)

NF Stabilized Condensate

NFC to Refinery/ Export

Sour Gas unit (6112)

Ethane Gas RecoveryLean Gas to Industries

Lean Gas to Power Plants

Gas to Fahahil Re‐Injection

Ethane Ex NGL‐1

Ethane Ex NGL‐2

Ethane Ex NGL‐4

Lean Gas ex. Extraction Unit

ERG Recovery

To Industries and Power Plants

ERG Recovery

Liquid Recovery Systems

• Store Feed & liquid Off Specification Products for Recycling after plant normalization

• The Project Provided Vessels/Pumps for Three main services to cater for the different plants

– Feed Storing Vessels (Plant Upsets)

– Off‐Spec Products Storing Vessels

– Liquid Disposal Vessels

Liquid Recovery Systems (NGL 1&2)

Liquid Recovery Systems (NGL 1&2)

Liquid Recovery Systems (NGL 1&2)

Liquid Recovery Systems (NGL 1&2)

Liquid Recovery Systems (NGL 1&2)

Liquid Recovery Systems (NGL 1&2)

Liquid Recovery Systems (NGL 1&2)

Liquid Recovery Systems (NGL 3)

Raw NGL Recovery Systems (NGL 4)

• Raw NGL Recovery :– Raw NGL Recovery Vessels:  6939‐V02 A/B/C

Flare Modification

Flare Modification (NGL ‐1,2 & 3)

• NGL‐1, NGL‐2 & NGL‐3 flares replaced & relocated

• Air assistance is given to LP and HP Flare for smokeless flaring

• Sonic flare tip to HP flare for complete combustion

Flare Modification (NGL ‐1&2)

RAG & FMP Project Benefits in 2008

• Ethane Recovered 7,663 MT 560,000 QAR

• Propane Recovered 780 MT 2,419,000 QAR

• Butane Recovered 533 MT 1,689,000 QAR 

• NGL Cond. Recovered 363 MT 1,124,000 QAR 

5,792,000 QAR

Thank You

Back‐Up Slides

Flare Modification (NGL ‐1&2)

Recommended Design Flare Radiation Levels

kW/m2 Condition

9.46 Exposure should be limited to a few seconds, sufficient for escape only

6.31 Exposure should be limited to 1 minute

4.73 Exposure should be limited to several minutes

1.58 Continuous Exposure is Safe

Ludwig E. (Applied Process Design for Chemical and Petrochemical Plants Vol.1)

Flare Modification (NGL ‐3)

Recommended Design Flare Radiation Levels

kW/m2 Condition

9.46 Exposure should be limited to a few seconds, sufficient for escape only

6.31 Exposure should be limited to 1 minute

4.73 Exposure should be limited to several minutes

1.58 Continuous Exposure is Safe

Ludwig E. (Applied Process Design for Chemical and Petrochemical Plants Vol.1)

Flare Modification (NGL ‐3)

Recommended Design Flare Radiation Levels

kW/m2 Condition

9.46 Exposure should be limited to a few seconds, sufficient for escape only

6.31 Exposure should be limited to 1 minute

4.73 Exposure should be limited to several minutes

1.58 Continuous Exposure is Safe

Ludwig E. (Applied Process Design for Chemical and Petrochemical Plants Vol.1)

Al‐Shaheen Field’s RAG Utilization• Installation of new Pre‐Flash Column Reboiler, 6103‐E‐16, replacing 6103‐E‐43

• Installation of 25 replacement trays in the Pre‐Flash Column, 6103‐C‐41 (trays 1 to 9 & 23‐38 only)

• Re‐impeller for the Pre‐Flash Column Raw NGL Pump,          6103‐P‐41A/B

• Improvements / re‐adjustments to existing process controls to achieve desired flow splits within the process

BACK

Flare Emission

Flare Total Emission*, tonnes per year

Composition**, wt%

NGL1&2 LP 2,390

NGL1&2 HP 4,350

NGL1&2 Acid Gas 1,262

NGL 3 LP 2,390

NGL 3 HP 3,287

NGL 3 Acid gas LP 1,482

NGL 3 Acid gas HP 2,390

CO2:15.24; SO2:Nil; NOx:0.01; CO:0.05; N2:72.28; HC:0.11; H2O:12.31

•Emissions during the normal flare operation.•Normally only purge gas and pilot gas is flared in all flares

Flare SO2 Emission

Maximum SO2 EmissionFlare

Normal Operation, tonnes/day

Emergency Situation*, tonnes/hour

NGL1&2 LP Nil 0.81

NGL1&2 HP Nil 36.85

NGL1&2 Acid Gas Nil 4.94

NGL 3 LP Nil 1.14

NGL 3 HP Nil 22.13

NGL 3 Acidgas LP Nil 14.65

NGL 3 Acidgas HP Nil 11.00

* Emergencies due to Plant Upsets, Fire in Plant, Power Failure etc. This will have low probability of occurrence and short lived.

Flare SO2 GLCMaximum SO2 GLC (24 Hour averaging)Flare

Normal Operation, µg/m3 Emergency Situation*, ppm

NGL1&2 LP Nil Negligible

NGL1&2 HP Nil Negligible

NGL1&2 Acid Gas Nil 0.21

NGL3 LP Nil Negligible

NGL3 HP Nil Negligible

NGL3 Acid gas LP Nil 0.38

NGL3 Acid gas HP Nil 0.002

Allowable limit 365 (24 hr) (As per Qatar Environmental

Protection Standard)

5.0 (15 minutes)(As per American Conference of Governmental Industrial

Hygienists, ACGIH)

•Emergencies due to Plant Upsets, Fire in Plant, Power Failure etc. This will have low probability of occurrence and short lived. All emergency situations are short lived and the allowable limit is the Threshold Limit Value – Short Term Exposure Limit (STEL) as per ACGIH is considered•GLC is based on 5m/s wind speed