Natural gas sweetening

Design of Sour Gas Design of Sour Gas Treatment PlantTreatment Plant

Faculty Advisor: Dr.Fahmi Abu Al-Rub

Industrial Contact: Dr.Mohamed Al-Marzouqi

Coordinator: Dr.Salah Al-Omary.

United Arab Emirates UniversityUnited Arab Emirates University

Faculty Of EngineeringFaculty Of Engineering

Graduation Project UnitGraduation Project Unit

Graduation Project IGraduation Project I

Done By : Osama Ali & Yousif Mohammed

GP 1 : Design of Sour Gas Treatment Plant

United Arab Emirates University

Faculty Of Engineering

Graduation Project Unit

Graduation Project I

Done by:

Osama AliOsama Ali 980715144980715144

Yousif MohammedYousif Mohammed 980710588980710588



•Introduction

•Processes Selection

•Absorption Process by Amine Solution



What is Sour Gas?

Sour Gas is acidic gases such as Carbon dioxide and hydrogen sulphide.

Natural GasNatural Gas

Non-Hydrocarbon

(Sour Gas)Hydrocarbon



Note: The composition of components is from ADMA Company



Industrial Industrial effectseffects

EnvironmentEnvironmental effectsal effects



- Corrosive material

- Reduce the heating value

- Non-combustible component



- H2S is a highly toxic

- Colorless

- Flammable gas

- 4.3% LEL and 45% HEL by volume with an auto-- ignition temperature of 500oF (292oC). Heavier than air (1.18 times heavier).

- It may accumulate in dangerous concentrations in drains, valve pits, vessels and tanks.



•Hydrogen sulphide must be less than 6 mg/m3 to prevent the effect of corrosion in process equipment.

•Carbon dioxide is limited to 2% maximum to prevent dilution of the heat producing combustible sales gas.



Conditions of Sour gas

Vapor fraction 1

Temperature (oC) 27

Pressure (psi) 200

Mass flow rate (lb/hr) 12720



Absorption Adsorption



Natural Gas

Sweet Gas

Lean Solvent

Rich Solvent

Absorption process is used to remove a component (solute) from the gas stream by contacting the gas with a liquid solution (solvent).



Adsorption is the process of removing impurities from a gas stream by means of a solid material called adsorbent that has special attraction for the impurities.

Done By : Osama Ali & Yousif MohammedDesign of Sour Gas Treatment Plant

•Absorption requires mass transfer of substance from the gas stream to the liquid.

•The component which is absorbed is called solute and the liquid is called solvent.

•The relation between Absorption & Stripping

•If the concentration of the vapor and liquid are in equilibrium, no driving force exist so no mass transfer will occur



High solubility. Low volatility. Easy to recovery. Low viscosity. Low cost.



The alkanolamines are the most generally accepted and widely used solvent for the removal of H2S and

CO2 from natural gas.

WaterSaltBaseAcid

OHSulfideeAeASH 22 minmin

OHCarbamateeAeACO 22 minmin



MonoEtanol Amine (MEA)

DiEthanol Amine (DEA)

Methyldiethanolamine (MDEA)



• From the three types of amines, DEA amine is selected. The reasons for select DEA are in following points:

1. DAE is much less corrosive to carbon steel than MEA

2. DEA is less volatile then MEA

3. MDEA is much less reactive than either DEA



Process DescriptionProcess DescriptionThe gas sweetening process consists basically of two parts :

a. Absorption b. Regeneration

Process ReactionProcess Reaction



•Absorption with amine was selected.

•Among the amine processes, the DEA process was found to be the best to treat the sour gas with the suggest specifications.

•Sour gas contains H2S and CO2, H2S was highly toxic, thus experiment analysis could not be carried out in our laboratories. Since H2S safety requirements are not available in the Chemical Engineering Department laboratories.

Natural gas sweetening

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