NGL Plants

7/30/2019 NGL Plants

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Advanced Gas Processing

A. ShahsavandA. Shahsavand

Chemical Engineering DepartmentChemical Engineering Department

Faculty of EngineeringFaculty of Engineering

Ferdowsi University of MashadFerdowsi University of Mashad

20102010


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Feedstock & Product

Receives associated gases from

crude oil production units orwellhead separators.

Produces sale gas, Ethane (as

petrochemical feed stock), LPG (C3 -

C4) and light naphtha (C5+)


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Onshore and Offshore

NGL plant facilities

Gas Compression

Onshore

Associated

Gases

Offshore

Associated

Gases

Acid Gas Removal

NGL Recovery Unit

Acid Gas

incineration

or SRU

Sale Gas C2 C5+C4

CondensateC3


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NGL Recovery Unit

A conventional natural gas liquid plantincludes a separator that receives a cooled lowpressure feed gas (heavy HC separation).

The separator is coupled to an absorber (ordistillation column) and a demethanizer.Refrigeration duty of the absorber anddemethanizer are provided at least in part by

expansion of a liquid portion of the cooled lowpressure feed gas and an expansion of a liquidabsorber bottom product.

Propane recovery is at least 99 mol %.


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Ethane Recovery

As ethane recovery becomes increasinglyeconomically attractive, various

configurations have been developed toimprove the recovery of ethane from natural

gas liquids (NGL).

Most commonly, numerous processesemploy either cooling of feed gases via turbo

expansion or a sub-cooled absorptionprocess to enhance ethane recovery.


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Typical NGL unitSlug

CatcherDehumidificationCondensate

Separator

Feed

gas

Water

Refrigeration

LPG Absorber

C5+

Recovery

Recovery

Refrigeration

& Compression

C2

C5+

C3 & C4


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Conventional NGL unit


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Ideas

Can we use new separationprocesses such as PSA or

membrane instead of conventionalRefrigeration process.

These new processes are more

energy efficient and may beattractive from economical point of

view.


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60 MMSCFD NGL Plant,

Alberta, Canada (Start up: January 1998 )


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Hawiyah NGL Recovery

Project, Saudi ArabiaThe Hawiyah NGL Recovery Program produces

310,000 bbl/d of ethane and NGL products from around

four billion SCFD of associated gas.

This project is completed in early 2008..

This plant also produces 170,000 bbl/d of condensate,

and 1,000 t/d of sulphur.

Facilities at the plant, in addition to the four gas-

processing trains that perform gas dehydration, dew-

point control and sales-gas compression, include two gas

sweetening and sulphur recovery trains, two condensate

stabilizers and two sour-water strippers.


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Supply and Demand


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NIOC associated

gas gathering systems


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AMAK Project


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Environmental Issues


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AMAK Products


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Economic Aspects

Annual Product Value:

Total Cost : 530 MMUSD

Payback period: 2 years


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AMAK Gas Treating Unit


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AMAK Compressor Station


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Kharg NGL recovery unit


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Kharg NGL recovery unit


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Approximate Location


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Approximate Location


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Kharg NGL unit Project


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Kharg Associated Gas

Gathering Project


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Onshore Acid Gas

303 MMSCFD303 MMSCFD

Containing Following Impurities:Containing Following Impurities:

H2S : 12.7 mole % (38.5 MMSCFD)

CO2 : 5.5 mole % (16.7 MMSCFD)

COS : 222 ppm

RSH : 217 ppm

RSR : 34 ppm


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Offshore Acid Gas

297 MMSCFD297 MMSCFD

Containing Following Impurities:Containing Following Impurities:

H2S : 3.8 mole % (11.3 MMSCFD)

CO2 : 4.6 mole % (13.7 MMSCFD)

COS : 88 ppm

RSH : 46 ppm

RSR : 4 ppm


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Problems & Solution

80 MMSCFD Acid Gas Removed

H2S : 50 MMSCFD (2034 tone sulfur) Problems: Sales and Marketing,

Warehousing

CO2 : 30 MMSCFD (Emission To Atm.) Problems: Greenhouse Gas, Environmental

Concerns


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Acid Gas Injection

Sour Gas Acid Gas

Sweet Gas

AGRAGR

C&CC&CDisposal

Well

T=40 C

P=180 Bar

Pipeline

Disposal

Layer


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Acid Gas Injection

Injection Depth: 4500m under seabed

In ection Time: 25 ears

Total Injection volume : 128 MMbbl

THE BIGGEST ACID GAS INJECTION

PLANT IN THE WORLD!


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Economical aspect


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Price Per Unit (2004)

Sales Gas 25 $/MSCM

Ethane 65 $/Tone

Price Correlation

Butane 406 $/Tone

Pentane 30 $/BarrelCondensate 35 $/Barrel


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Economical aspect

Annual product value: 720 MMUSD

Onshore NGL facilities cost: 1200 MMUSD

Onshore GC facilities cost: 67 MMUSD

Offshore pipeline: 90 MMUSD




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Sox Emission by Flares


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Nox Emission by Flares


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NOx and Sox emission Comparison


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Siri NGL recovery unit


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Siri NGL unit Project


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Economical aspect


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Siri Island Associated Gas

Gathering Project


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Economical Aspect

Annual product value: 180 MMUSD

Onshore NGL facilities cost: 216 MMUSD

Onshore GC facilities cost: 12 MMUSD

Offshore pipeline: 72 MMUSD




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Environmental Aspect


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Project Schedules (Jan 2005)

Siri Onshore NGL plant:

40 months (ongoing)

s ore p pe ne pro ect:

Executed

Offshore Gas compression platform:

12 months (ongoing)


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Sirri NGL plant to be completed

in two years (Jan 2007)Sirri NGL Plant will collect 140 MMSCFD of associated gases, of

which 40 mcf will be used to produce condensates. This is equal to the

production of 12,000 barrels per day of condensates,

-

construct the plant have so far progressed by 20 percent and expected

to come on stream over the next two years.

Gases from the fields are to be sent to power plants at Qeshm and

Kish, while the extracted gas condensates are to be exported. The gas

transfer pipelines from Sirri to Qeshm and Kish have been completed

in offshore part.


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Canadian NGL Prices

C4 ($/m3)C3 (US/US gal.)C3 ($/m3)Date

245.0090.75 ( 40 US$/bbl)282.3602/07...

255.0088.95269.7412/06

380.48103.44307.2308/06

345.1693.63279.1005/06

334.03107.60332.7712/05


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Iranian NGL units

NGL 100, 200, 300 (Aghajari)

NGL 400, 500, 600 (Ahwaz)

NGL 700, 800, 900 (Ahwaz)

NGL 1000, 1100, 1200 (Ahwaz)

NGL 1300, 1400 (Ahwaz)

NGL 1500 (Karanj)

Documents

NGL Plants