Hydrogen sulfide-carbon dioxide membrane separation systems and processes

Patent metadata

Field	Value
Publication number	US-11420153-B2
Application number	US-202016877433-A
Country	US
Kind code	B2
Filing date	May 18, 2020
Priority date	May 17, 2019
Publication date	Aug 23, 2022
Grant date	Aug 23, 2022

Abstract

A process for recovering sulfur from a sour gas is provided. The process includes the steps of: providing the sour gas to a membrane separation unit having a carbon dioxide-selective membrane that comprises a perfluoropolymer, wherein the sour gas comprises carbon dioxide and at least 1 mol % hydrogen sulfide; separating the sour gas using the carbon dioxide-selective membrane in the membrane separation stage to obtain hydrogen sulfide-enriched gas and hydrogen sulfide-stripped gas, wherein the hydrogen sulfide-enriched gas has a hydrogen sulfide concentration of at least 20 mol %, and wherein the hydrogen sulfide-stripped gas comprises carbon dioxide; and processing the hydrogen sulfide-enriched gas in a sulfur recovery unit to obtain sulfur.

First claim

We claim:

1. A process for recovering sulfur from a sour gas, the process comprising the steps of:
providing the sour gas to a membrane separation unit having a membrane stage that comprises a carbon dioxide-selective membrane, the carbon dioxide-selective membrane comprising a perfluoropolymer and having a carbon dioxide-hydrogen sulfide selectivity greater than 10, and wherein the sour gas comprises carbon dioxide and at least 1 mol % hydrogen sulfide;
separating the sour gas using the carbon dioxide-selective membrane in the membrane separation stage to obtain hydrogen sulfide-enriched gas and hydrogen sulfide-stripped gas, wherein the hydrogen sulfide-enriched gas has a hydrogen sulfide concentration of at least 20 mol %, and wherein the hydrogen sulfide-stripped gas comprises carbon dioxide; and
processing the hydrogen sulfide-enriched gas in a sulfur recovery unit to obtain sulfur.

2. The process of claim 1 , wherein the hydrogen sulfide-stripped gas further comprises residual hydrogen sulfide, and wherein the process further comprises the steps of:
oxidizing the hydrogen sulfide-stripped gas in an oxidizer such that residual hydrogen sulfide in the hydrogen sulfide-stripped gas is reacted with oxygen to produce sulfur dioxide-bearing gas.

3. The process of claim 2 , further comprising the step of:
venting the sulfur dioxide-bearing gas to the atmosphere.

4. The process of claim 2 , further comprising the step of:
capturing the sulfur dioxide-bearing gas for use in enhanced oil recovery operations.

5. The process of claim 1 , wherein the hydrogen sulfide-stripped gas has a concentration of hydrogen sulfide that is less than 0.1 mol %.

6. The process of claim 1 , wherein the hydrogen sulfide-stripped gas has a concentration of hydrogen sulfide that is less than 0.015 mol %.

7. The process of claim 1 , wherein the hydrogen sulfide-stripped gas has a concentration of hydrogen sulfide that is less than 0.01 mol %.

8. The process of claim 1 , wherein the hydrogen sulfide-enriched gas has a concentration of hydrogen sulfide that is greater than 80 mol %.

9. The process of claim 1 , wherein the hydrogen sulfide-enriched gas has a concentration of hydrogen sulfide that is greater than 90 mol %.

10. The process of claim 1 , wherein the hydrogen sulfide-enriched gas has a concentration of hydrogen sulfide that is greater than 95 mol %.

11. The process of claim 1 , wherein the carbon dioxide-selective membrane has carbon dioxide-hydrogen sulfide selectivity greater than 20.

12. The process of claim 1 , wherein the carbon dioxide-selective membrane has carbon dioxide-hydrogen sulfide selectivity greater than 30.

13. The process of claim 1 , wherein the membrane separation unit has a single-pass membrane stage configuration.

14. The process of claim 1 , wherein the membrane separation unit has a two-stage retentate-in-series membrane configuration.

15. The process of claim 1 , wherein the membrane separation unit has a two-stage permeate-in-series membrane configuration.

16. The process of claim 1 , wherein the membrane separation unit has a three-stage membrane configuration.

17. The process of claim 1 , wherein the perfluoropolymer comprises a monomer having the chemical structure:

18. The process of claim 1 , wherein the perfluoropolymer comprises a monomer having the chemical structure:

19. The process of claim 1 , wherein the perfluoropolymer comprises a monomer having a chemical structure selected from the group consisting of

and combinations of the same.

Assignees

• Saudi Arabian Oil Co
• Membrane Tech And Research Inc

Inventors

• Vaidya Milind M
• Duval Sebastien A
• Hamad Feras
• Baker Richard
• Merkel Tim
• Lokhandwala Kaaeid
• Bahamdan Ahmad A
• Al-Otaibi Faisal D

Classifications

• Y02P20/151

  Reduction of greenhouse gas [GHG] emissions, e.g. CO2 · CPC title

• Y02C20/40

  of CO2 · CPC title

• C01B17/167

  Separation · CPC title

• B01D53/22

  by diffusion (manufacturing semi-permeable membranes B01D67/00; form, structure or properties of semi-permeable membranes B01D69/00; material for semi-permeable membranes B01D71/00) · CPC title

• B01D53/226 Primary

  in serial connexion · CPC title