Aqueous solutions of amine functionalized ionic compounds for carbon capture processes

Patent metadata

Field	Value
Publication number	US-9751044-B2
Application number	US-201514870318-A
Country	US
Kind code	B2
Filing date	Sep 30, 2015
Priority date	Dec 30, 2010
Publication date	Sep 5, 2017
Grant date	Sep 5, 2017

Abstract

An aqueous ionic absorbent solution is disclosed containing (a) about 15 wt. % to about 80 wt. % of one or more diluents, based on the total weight of the aqueous ionic absorbent solution; and (b) an ionic absorbent containing a cation and an anion comprising an amine moiety.

First claim

What is claimed is:

1. A process for separating carbon dioxide (CO 2 ) from a carbon dioxide-containing gas stream, the process comprising:
(a) contacting the carbon dioxide-containing gas stream with an aqueous ionic absorbent solution under absorption conditions to absorb at least a portion of the CO 2 from the carbon dioxide-containing gas stream and form a CO 2 -absorbent complex; wherein the aqueous ionic absorbent solution has a viscosity of about 0.1 to about 100 centistokes (cSt) and further wherein the aqueous ionic absorbent solution comprises (i) about 40 wt. % to about 80 wt. % of one or more diluents, based on the total weight of the aqueous ionic absorbent solution; and (ii) an ionic absorbent selected from the group consisting of tetrabutylammonium N-propyl-N-(3-sulfopropyl)amine, tetrabutylphosphonium N-isopropyl-N-(3-sulfopropyl)amine, tetraethylammonium N-isopropyl-N-(3-sulfopropyl)amine and mixtures thereof; and
(b) recovering a gaseous product having a reduced CO 2 .

2. The process of claim 1 , wherein the carbon dioxide-containing gas stream is flue gas and the aqueous ionic absorbent solution absorbs higher than about 0.5 mol CO 2 per mol ionic absorbent at 40° C. with a CO 2 partial pressure in the range of 1 to 20 psia.

3. The process of claim 1 , wherein the one or more diluents comprise water.

4. The process of claim 1 , wherein the one or more diluents comprise a diluent selected from the group consisting of a monohydric alcohol, a polyol and mixtures thereof.

5. The process of claim 1 , wherein the amount of the one or more diluents is from about 40 wt. % to about 70 wt. % diluent, based on the total weight of the aqueous ionic absorbent solution.

6. The process of claim 1 , wherein the amount of the one or more diluents is from about 40 wt. % to about 60 wt. % diluent, based on the total weight of the aqueous ionic absorbent solution.

7. The process of claim 1 , further comprising (i) pressurizing the CO 2 -absorbent complex to a pressure of greater than about 1.9 bar to about 10 bar and (ii) heating the pressurized CO 2 -absorbent complex to recover an ionic absorbent stream depleted in CO 2 .

8. The process of claim 7 , wherein the pressurized CO 2 -absorbent complex is heated to a temperature ranging from greater than 60° C. to about 80° C.

9. The process of claim 7 , wherein the pressurized CO 2 -absorbent complex is heated to a temperature ranging from greater than 100° C. to about 120° C. under atmospheric conditions.

10. The process of claim 7 , wherein the pressurized CO 2 -absorbent complex is heated to a temperature ranging from about 120° C. to about 200° C. under high-pressure conditions including a pressure of greater than about 1.9 bar to about 10 bar.

Assignees

• Chevron Usa Inc
• Univ South Alabama

Inventors

• Chinn Daniel
• Cooper Rusell Evan
• He Zunqing
• Davis Jr James H
• West Kevin N
• Timken Hye Kyung
• Driver Michael S

Classifications

• Y02C20/40

  of CO2 · CPC title

• Y02C10/04

  Cross-Sectional Technologies · mapped topic

• B01D2252/204

  Amines · CPC title

• B01D53/1493

  Selection of liquid materials for use as absorbents · CPC title

• B01D53/62 Primary

  Carbon oxides · CPC title