1. Chris, Stephanie, Kyle, Mariam
Gas Treatment Plant
Chris, Stephanie, Kyle, Mariam

2. What is Shale gas? And why is it important?
Is natural gas trapped within shale formations.
And why is it important?
Energy dependence
Reduce greenhouse gas emissions

3. Purpose Take raw shale gas and purify.
Produce compressed natural gas/pipeline gas.
Produce liquefied natural gas (LNG)
Supply methane for Ammonia Plant, Air Separations and Syngas Plant, the Direct Iron Reduction Plant, and Combined Heat/Power plant.
Supply Nitrogen (N2) to Ammonia Plant.
Produce natural gas liquids (NGL) for sale.

4. Shale Gas Composition

5. Design Basis

6. First Step: Water Removal and Condensation

7. First Step: Water Removal and Condensation
Gravity Separation
Example of Horizontal Separator

8. First Step: Water Removal and Condensation
Purpose: To separate gas/liquid phases.
Additionally water and NGLs may be separated within the same unit given proper settling time.
Proper pressure and liquid-level controls required.
A mist extractor at gas exit captures droplets too small to settle by gravity.
The sudden change in momentum generates the separation of liquid from gas.

9. Second Step: Acid Gas Removal

10. Second Step: Acid Gas Removal
Amine Treating
Most commonly used process for removing sour gas in natural gas purification plants
Most Common Amines Used
Monoethanolamine
Diethanolamine
Methylethanolamine
Diisopropylamine

11. Second Step: Acid Gas Removal
Pressure Swing Adsorption (PSA)

12. Second Step: Acid Gas Removal
Benfield
Process
Thermally regenerated cyclical solvent process
Uses an activated, inhibited hot potassium carbonate solution to remove CO2, H2S and other acid gas components

13. Second Step: Acid Gas Removal
Sulfinol Process
For selective absorption of H2S, COS and mercaptans, while co-absorbing only part of the CO2
The solvent is composed of Sulfolane, DIPA or MDEA and water
Great for treating large quantity of gas such as natural gas which are at elevated pressure

14. Second Step: Separation H2S and CO2

15. Second Step: Separation H2S and CO2
Room-
Temperature Ionic Liquid (RTILs)
An ionic liquid comprising an anion having a carboxylate function and an effective amount of water is used as an adsorbent to selectively complex the CO2 yielding a gaseous stream with a greatly reduced CO2 content.

16. Third Step: Separation of H2S and recycle

17. Third Step: Separation of H2S and recycle
Claus Process

18. Third Step: Separation of H2S and recycle
Scot process

19. Third Step: Separation of H2S and recycle
Clauspol process

20. Fourth Step: Dehydration

21. Fourth Step: Dehydration
Glycol Separation
Commonly used
Triethylene Glycol
Glycol absorbs water
Can potentially vaporize hydrocarbons

22. Fifth Step: Nitrogen Removal

23. Fifth Step: Nitrogen Removal
Methods: Cryogenics, Pressure Swing Adsorption, Membrane separation and lean oil absorption.
Cryogenics: The only widely acceptable method on the industrial scale.
Costs $ /Mscf for plants handling 75 MMscfd
Costs $1.00+/Mscf for plants handling 2 MMscfd or less.
Methane and Nitrogen condense at different temperatures -256F and -346F respectively.
Membrane Process: No membrane alone has the Nitrogen/Methane separation characteristics.
PSA and Lean Oil Absorption: Prohibitively high capital costs and require lower volume flows.

24. Sixth Step: Natural Gas Liquid Recovery

25. Sixth Step: Natural Gas Liquid Recovery
Turbo Expander and Demethanizer
Turbine through which a high pressure gas is expanded to produce work that is often used to drive a compressor
Low-temperature distillation column to separate CH4 and Natural Gas Liquids (NGLs)

26. Seventh Step: Fractionation

27. Seventh Step: Fractionation

28. Eighth Step: Liquefaction and compression

29. Eighth Step: Liquefied Natural Gas (LNG) Production
Composition:
Methane 90-95%
Nitrogen 1-4%
C2+ hydrocarbons 1-5%
CO2 <1%
Example of coil-wound LNG heat exchanger

30. LNG Transportation
LNG occupies 1/600th the volume of natural gas in gaseous form.
LNG is necessary when no pipeline exists.
Efficient method for exporting natural gas.
Example of LNG tanker

31. Questions?