Egyptian Natural Gas Co. (Gasco)

Gas Facilities DepartmentTraining Course on

Natural Gas Processing

Presented by:Ahmed M.Samy

25 July 2011

Why Summer Training??

ProjectInterview

Natural Gas Composition

Hydrocarbon gases Non-Hydrocarbon gases

Propane C3

Ethane C2

Methane C1

Butane C4

Pentane C5

Hexane+ C6+

Water vapor H2O(V)

Nitrogen N2

Carbon dioxide CO2

Hydrogen sulfide H2S

What is the meaning of

+ ?

Mercury Hg

Natural Gas Typical Composition

Hydrocarbon gases Non-hydrocarbon gases

Propane C3

Ethane C2

Methane C1

Butane C4

Pentane C5

Hexane+ C6+

Water vapor H2O(V)

Nitrogen N2

Carbon dioxide CO2

Hydrogen sulfide H2S 77-99 %

0.05-20 %

0.01-5 %

0-1.74 %

0-0.24 %

0-0.08 %

0.11-.83 %

0.1-3.44 %

0-4 PPM

Natural Gas Classification

Composition Reservoir

Lean Rich

Hydrocarbon gases Non-hydrocarbon gases

SweetSour Wet Dry

Propane C3

Ethane C2

Butane C4

Pentane C5

Hexane+ C6+

Propane C3

Ethane C2

Butane C4

Pentane C5

Hexane+ C6+

CO2

H2SH2S

CO2

H2O(V) H2O(V)

Note: The C1 is the main component in both

Natural Gas Composition

Natural gas reservoir

Oil and associated gas reservoir

Natural Gas Reservoir

Natural Gas in Egypt

TCF: Trillion Cubic feet

Gas reserves

Uses of natural gas

Electricity 56 %Industry 29 %

Petrochemical 12%

Domestic 2% CNG 1%

Natural Gas Processing

UP-Stream Down-Stream

Gas Productio

n

Gas treatment Consumers

Factory

Gas production from wells

Water removal (Dehydration)

Acid gas removal (Sweeting)

Compression

Field Treatment (Up-Stream Process)

H2S

CO2

Condensate

Free Water

Oil

Corrosion

H2O(V)H.C.+ H2O Hydrate(Physical combination)

Pipe blockage

Liquids removal

National Grid

?

Process ContaminantReason

Acid gas

H2o

Acid

National Grid

Field Treatment ConsumersNational

Grid

Well

Field Treatment ConsumersNational

Grid

Rich Gas Well

In Case Rich Gas

Factory

NGL

Sales gas

Down-Stream process

Up- Stream Process Down- Stream Process

C1C2C3C4C5+

Field Treatment ConsumersNational

Grid

Lean Gas Well

In Case Lean Gas

Factory

LNG

Sales gas

C1C2

Rich gas

National Grid

NGL????$

$NGL

Products

GASCO Mission

Gas Processing Gas Distribution Gas Transmission

Factories National Grid

WD Gas Fields

NGL

WDGC Western Desert Gas Complex

Sales Gas

C2/C3 (gas)

C3 (Liq.)

LPG (Liq.)

Cond. (Liq.)

El-Salam El-Tarek El-Obayid

El-Qasr

National Grid

Sidpec

Naftomar

WDGC

Petro Gas

Ameryia crude oil

WD Gas Fields

NGL

Ameryia LPG Recovery Plant

Sales Gas

C2/C3 (gas)

LPG (Liq.)

Cond. (Liq.)

National Grid

WDGC

Ameryia LPG

Petro Gas

Ameryia crude oil

Bed 3Abu-sananBed 2

Components

C7+ C6 Nc5 IC5 NC4

IC4 C3 C2 C1 N2 H2S Co2

Acid gas

LNG

LPG

Commercial propane

Condensate

NGL

Summary

Gas Productio

n

Gas treatment

NGL

LNG

Sales gas

Export

C2/C3

C3

LPG(C3/C4)

CondensateC5+

Petrochemicals

Industry

CNG stations

Domestic

Domestic

Export

Oil refinery(API)

Ric

h g

as

Lean

gas

Up-Stream ProcessDown-Stream

ProcessProducts

NGL Plant

Dehydration

Chilling

Fractionation

Storage

National Grid

NGL

FEED

GAS

SALES GAS

H2O(V)

PRODUCTS

Dehydration

Dehydration

Chilling

FractionationStorage

H2O(V)

National Grid

NGL

FEED

GAS

SALES GAS

PRODUCTS

Hydrate

H2O

CH4

Hydrate Triangle

Hydrate

H2O

P T

Psi

DehydrationAdsorption Absorption

Solid Surface

Molecules

Liquid Solvent

Molecules

Molecular sieve

Wet gas

Dry gas

Hot Regen gas

Wet Regen gas

Cold Regen gas

Hot Regen gas

HeatingAdsorption Cooling

Dehydration PFD

PFD: Process Flow Diagram

840 12 16 20 24

KV1

KV2

KV3

KV4

KV5

KV6

KV7

KV8

KV9

KV10

KV11

KV12

KV13

D1 D2 D3

D1D2D3

Chilling

Dehydration

Chilling

FractionationStorage

National Grid

NGL

FEED

GAS

SALES GAS

H2O(V)

PRODUCTS

Chilling

Turbo-Expander Joule-Thomson valve

High PHigh T

Low PLow T

High PHigh T

Low PLow T

Pressure reduction Refrigeration

High T Low T

Refrigerant

Refrigerant

Turbo-Expander Joule-Thomson valve

• For Gas only• Produce work• More efficient

• For Liquid and Gas• Doesn't produce work

ΔP ΔT ΔP ΔT

Expander CompressorW

Pressure reduction

Low Pressure

gas

High Pressure

gas

Low Pressure

gas

High Pressure

gas

Turbo-Expander Scheme

Heat Exchanger

Tube side Flow out

Shell side Flow in

Tube side Flow in

Shell side Flow out

Compression

Field Treatment ConsumersNational

Grid

Well Pipe storage

Pressure reduction

NGL

ChillingRefrigeration

Refrigeration Cycle

Expansion

Evaporation

Compression

Condensation

Refrigeration Cycle

Joule-Thomson valve

Air cooler

Process GasLatent heat of vaporization

Liquid Refrigerant

Vapor Refrigerant

Condenser

Compressor

Evaporator -Chiller

Liquid Refrigerant

Gas Refrigerant

Hot Process Gas

Cold Process Gas

Chiller-Evaporator

Chiller-Evaporator 3D

Propane Refrigeration Cycle

-42 °C1 bar 80 °C

20 bar

50 °C20 bar

-42 °C1 bar

Joule-Thomson valve

Air cooler

Process GasLatent heat of vaporization

Liquid Propane

Vapor Propane

Condenser

Compressor

Evaporator -Chiller

GAS - (STEAM)

LIQUID - (WATER)

SOLID - (ICE)0° C

100° C120° C

419 KJ 2676 KJ

1 kg water at 1 bar pressure

D335 KJ

Refrigeration Scheme

NGL Plant

Dehydration

Chilling

Fractionation

Storage

National Grid

NGL

FEED

GAS

SALES GAS

H2O(V)

PRODUCTS

Fractionation

•Distillation :The process of separating materials by successively heating to vaporizea portion and then cooling to liquefy a part of the vapor. Materials to be separated must differ in boiling point and/or relative volatility.

Top Product

Bottom Product

Condenser

Reboiler

NGL

C2/C3

NGL Plant

Dehydration

Chilling

Fractionation

Storage

National Grid

NGL

FEED

GAS

SALES GAS

H2O(V)

PRODUCTS

Ordinary evaporation is a surface phenomenon - some molecules have enough kinetic energy to escape. If the container is closed, an equilibrium is reached where an equal number of molecules return to the surface. The pressure of this equilibrium is called the saturation vapor pressure.

The boiling point is defined as the temperature at which the saturated vapor pressure of a liquid is equal to the surrounding atmospheric pressure

Evaporation Boiling

Storage

vapor pressure (true vapor pressure): The pressure exerted by the equilibriumvapor of a liquid when confined in a closed tank.

vapor pressure of water = 1 atm @ 100 °C

Water boils at 100 °C

Because

V.P. verses T

Storage pressure = Vapor pressure

1 atm

Storage

Propane

LPG

Condensate

Storage pressure = Vapor pressure

Propane

LPG

Condensate

Pressurized

Non- Pressuried

Vapor pressure of C3&C4 @ ambient T < 1 atm

Vapor pressure of C5 @ ambient T > 1 atm

Pressurized

Liquid Storage

Refrigerated

T) Ambient < T) Critical T) Ambient > T) Critical

Propane Methane

96 °C -82 °C

LPG Specs

V.P.=10 bar @ 50 °C

Rault lawVapor pressure of mixture (C3/C4) = (XC3*V.P. C3) + (XC4*V.P. C4)

WDGC PFD

Ameryia LPG PFD

Exhaust500 °C

Axial compressor Turbine Centrifugalcompressor

Combustion chamber

Air

Fuel

Low pressure gas

High pressure gas