Removal of carbon dioxide from a fluid flow

Patent metadata

Field	Value
Publication number	US-10279309-B2
Application number	US-201515506646-A
Country	US
Kind code	B2
Filing date	Aug 20, 2015
Priority date	Aug 25, 2014
Publication date	May 7, 2019
Grant date	May 7, 2019

Abstract

An absorbent for removing carbon dioxide from a fluid stream, comprising an aqueous solution a) of an amine of the general formula (I)

in which R 1 , R 2 and R 3 are each independently selected from C 1-4 -alkyl and C 1-4 -hydroxyalkyl; each R 4 is independently selected from hydrogen, C 1-4 alkyl and C 1-4 -hydroxyalkyl; each R 5 is independently selected from hydrogen, C 1-4 -alkyl and C 1-4 -hydroxyalkyl; X is OH or NH(CR 1 R 2 R 3 ); m is 2, 3, 4 or 5; n is 2, 3, 4 or 5; and o is 0 or 1; and b) at least one activator selected from b1) a sterically unhindered primary amine and/or a sterically unhindered secondary amine; and a carboanhydrase. The absorbent allows rapid absorption of carbon dioxide from fluid streams.

First claim

The invention claimed is:

1. An absorbent for removing carbon dioxide from a fluid stream, the absorbent comprising an aqueous solution comprising:
a) an amine of formula (I):

and
b) at least one activator which is a 5-, 6- or 7-membered saturated heterocycle comprising at least one NH group and optionally one or two further heteroatoms, which are nitrogen or oxygen, in the ring,
wherein:
R 1 , R 2 and R 3 are each independently C 1-4 -alkyl or C 1-4 -hydroxyalkyl;
each R 4 is independently hydrogen, C 1-4 -alkyl or C 1-4 -hydroxyalkyl;
each R 5 is independently hydrogen, C 1-4 -alkyl or C 1-4 -hydroxyalkyl;
X is OH or NH(CR 1 R 2 R 3 );
m is 2, 3, 4 or 5;
n is 2, 3, 4 or 5; and
o is 0 or 1.

2. The absorbent according to claim 1 , wherein a molar ratio of b) to a) is from 0.05 to 1.0.

3. The absorbent according to claim 1 , wherein a total amount of a) and b) in the aqueous solution is 10% to 60% by weight.

4. The absorbent according to claim 1 , wherein the amine a) is selected from the group consisting of 2-(2-tert-butylaminoethoxy)ethanol, 3-(tert-butylamino)propanol, 4-(tert-butylamino)butanol, 2-(2-tert-amylaminoethoxy)ethanol, 2-(2-(1-methyl-1-ethylpropylamino)ethoxy)ethanol, 2-(tert-butylamino)ethanol and (2-(tert-butyl amino)ethyl)methylamine.

5. The absorbent according to claim 1 , wherein the at least one activator is selected from the group consisting of piperazine, 2-methylpiperazine, N-methylpiperazine, N-ethylpiperazine, N-(2-hydroxyethyl)piperazine, N-(2-aminoethyl) piperazine, homopiperazine, piperidine and morpholine.

6. The absorbent according to claim 1 , wherein the aqueous solution further comprises at least one organic solvent.

7. The absorbent according to claim 1 , wherein the aqueous solution further comprises at least one acid.

8. The absorbent according to claim 1 , which does not contain a phosphonic acid.

9. A process for removing carbon dioxide from a fluid stream, the processing comprising:
contacting the fluid stream with the absorbent according to claim 1 , thereby obtaining a treated fluid stream and a carbon dioxide-laden absorbent.

10. The process according to claim 9 , wherein a partial carbon dioxide pressure in the fluid stream is from 0.01 to less than 3.0 bar.

11. The process according to claim 9 , wherein a partial carbon dioxide pressure in the treated fluid stream is less than 0.05 bar.

12. The process according to claim 9 , wherein the fluid stream is a hydrocarbonaceous fluid stream.

13. The process according to claim 9 , wherein the fluid stream is an oxygenous fluid stream.

14. The process according to claim 9 , wherein the carbon dioxide-laden absorbent is regenerated by at least one measure selected from the group consisting of
i. heating,
ii. decompression, and
iii. stripping with an inert fluid.

Assignees

• Basf Se

Inventors

• Ingram Thomas
• Notz Ralf
• Vorberg Gerald
• Sieder Georg
• Lozano Martinez Gustavo Adolfo
• Garcia Andarcia Hugo Rafael

Classifications

• B01D2252/2041

  Diamines · CPC title

• B01D53/1475 Primary

  Removing carbon dioxide · CPC title

• B01D2252/602

  Activators, promoting agents, catalytic agents or enzymes · CPC title

• B01D2252/502

  having two or more functionalities in the same molecule other than alkanolamine · CPC title

• B01D53/1493 Primary

  Selection of liquid materials for use as absorbents · CPC title