Process for increased selectivity and capacity for hydrogen sulfide capture from acid gases

Patent metadata

Field	Value
Publication number	US-9962644-B2
Application number	US-201514980634-A
Country	US
Kind code	B2
Filing date	Dec 28, 2015
Priority date	Dec 28, 2015
Publication date	May 8, 2018
Grant date	May 8, 2018

Abstract

A process for selectively separating H 2 S from a gas mixture which also comprises CO 2 is disclosed. A stream of the gas mixture is contacted with an absorbent solution comprising one or more amines, alkanolamines, hindered alkanolamines, capped alkanolamines, or mixtures thereof. The H 2 S/CO 2 selectivity of the absorbent solution is preferably greater than about 4.0 for an acid gas loading [mol(CO 2 +H 2 S)/mol(amine)] between about 0.2 and about 0.6, and is achieved by reducing pH of the absorbent solution.

First claim

What is claimed is:

1. A process for selectively separating H 2 S from a gas mixture which also comprises CO 2 , the process comprising:
contacting a stream of the gas mixture with an absorbent solution comprising methoxyethoxyethoxyethanol-t-butylamine (M3ETB);
wherein the M3ETB concentration in the absorbent solution is between 20 and 30 wt %.

2. The process of claim 1 , wherein the M3ETB concentration in the absorbent solution is between 25 and 30 wt %.

3. The process of claim 1 , wherein the H 2 S/CO 2 selectivity of the absorbent solution is greater than about 5.0 over the entire acid gas loading [mol(CO 2 +H 2 S)/mol(amine)] range between 0.2 and 0.55.

4. The process of claim 1 , wherein the H 2 S/CO 2 selectivity of the absorbent solution is greater than about 6.0 over the entire acid gas loading [mol(CO 2 +H 2 S)/mol(amine)] range between 0.2 and 0.55.

5. The process of claim 1 , wherein the H 2 S/CO 2 selectivity of the absorbent solution is greater than about 7.0 over the entire acid gas loading [mol(CO 2 +H 2 S)/mol(amine)] range between 0.2 and 0.55.

6. A process for selectively separating H 2 S from a gas mixture which also comprises CO 2 , the process comprising:
contacting a stream of the gas mixture with an absorbent solution comprising methoxyethoxyethoxyethanol-t-butylamine (M3ETB);
wherein the M3ETB concentration in the absorbent solution is between 25 and 30 wt %.

7. The process of claim 6 , wherein the H 2 S/CO 2 selectivity of the absorbent solution is greater than about 5.0 over the entire acid gas loading [mol(CO 2 +H 2 S)/mol(amine)] range between 0.2 and 0.55.

8. The process of claim 6 , wherein the H 2 S/CO 2 selectivity of the absorbent solution is greater than about 6.0 over the entire acid gas loading [mol(CO 2 +H 2 S)/mol(amine)] range between 0.2 and 0.55.

9. The process of claim 6 , wherein the H 2 S/CO 2 selectivity of the absorbent solution is greater than about 7.0 over the entire acid gas loading [mol(CO 2 +H 2 S)/mol(amine)] range between 0.2 and 0.55.

Assignees

• Exxonmobil Res & Eng Co
• Basf Ag

Inventors

• Pereira Carla S
• Siskin Michael
• Ingram Thomas
• Vorberg Gerald
• Ernst Martin

Classifications

• B01D53/1493 Primary

  Selection of liquid materials for use as absorbents · CPC title

• B01D2252/20489

  with two or more hydroxyl groups · CPC title

• B01D53/18

  Absorbing units; Liquid distributors therefor (B01D3/16, B01D3/26, B01D3/30 take precedence; packing elements B01J19/30, B01J19/32) · CPC title

• B01D2257/304

  Hydrogen sulfide · CPC title

• C10L3/10

  Working-up natural gas or synthetic natural gas · CPC title