Method for regenerating an amine-based, acid gas absorbent using a catalyst mixture containing silver oxide and silver carbonbate

Patent metadata

Field	Value
Publication number	US-11198090-B2
Application number	US-201916500287-A
Country	US
Kind code	B2
Filing date	Feb 18, 2019
Priority date	Oct 2, 2018
Publication date	Dec 14, 2021
Grant date	Dec 14, 2021

Abstract

A method for regenerating an amine-based, acid gas absorbent using a mixed catalyst containing silver oxide and silver carbonate includes the steps of absorbing an acid gas into an acid gas absorbent having an amine group to obtain an acid gas-absorbed absorbent; and regenerating the amine-based, acid gas absorbent by adding a catalyst mixture containing silver oxide and silver carbonate to the acid gas-absorbed absorbent and by removing the acid gas at a temperature ranging from 40° C. to 86° C. When the amine-based acid gas absorbent is an acid gas absorbent solution and when the acid gas that is absorbed into the acid gas absorbent solution is carbon dioxide, the catalyst mixture efficiently promotes decomposition of carbon dioxide-bound carbamate in the acid gas absorbent solution that absorbs the carbon dioxide through a novel catalytic reaction pathway.

First claim

The invention claimed is:

1. A method for regenerating an amine-based, acid gas absorbent using a catalyst mixture containing silver oxide and silver carbonate, the method comprising the steps of:
absorbing an acid gas into an acid gas absorbent having an amine group to obtain an acid gas-absorbed absorbent; and
regenerating the acid gas absorbent by adding a catalyst mixture containing silver oxide and silver carbonate to the acid gas-absorbed absorbent and by removing the acid gas at a temperature ranging from 40° C. to 86° C.

2. The method for regenerating an amine-based, acid gas absorbent of claim 1 , wherein the acid gas absorbent having an amine group is selected from the group consisting of monoethanolamine (MEA), diethanolamine (DEA), triethanolamine (TEA), tetraethylenepentamine (TEPA), triethylenetetramine (TETA), N-methyl diethanolamine (MDEA), 3-isobutoxypropylamine, dimethylaminoethylamine, diglycolamine (DGA), hexylamine, 2-amino-2-methylpropanol (AMP), hexamethylenediamine (HMDA), propylamine, dipropylamine, butylamine, isobutylamine, 2-ethylhexylamine, 4-aminobutanol, 3-Methoxypropylamine, allylamine, methyldiallylamine, pentylamine, isoamylamine, N-methylethylamine, 2-octylamine, 2-hydroxyethylaminopropylamine, piperazine, triisopropanolamine (TIPA), and combinations thereof.

3. The method for regenerating an amine-based, acid gas absorbent of claim 1 , wherein the amine-based, acid gas absorbent is monoethanolamine (MEA) or piperazine.

4. The method for regenerating an amine-based, acid gas absorbent of claim 1 , wherein the catalyst mixture is added in an amount of 0.1 to 20 parts by weight based on weight of the acid gas absorbent.

5. The method for regenerating an amine-based, acid gas absorbent of claim 1 , wherein the catalyst mixture containing the silver oxide and the silver carbonate is mixed in a weight ratio of the silver oxide to the silver carbonate ranging from 1:0.1 to 1:2.

6. The method for regenerating an amine-based, acid gas absorbent of claim 1 , wherein the method further comprises the steps of:
reusing a regenerated acid gas absorbent for absorbing the acid gas;
recovering the catalyst mixture to provide a recovered catalyst mixture; and
reusing the recovered catalyst mixture to regenerate the acid gas-absorbed absorbent.

7. The method for regenerating an amine-based, acid gas absorbent of claim 1 , wherein the amine-based, acid gas absorbent is an absorbent solution, wherein the acid gas that is absorbed into the absorbent solution is carbon dioxide, and wherein the catalyst mixture promotes decomposition of carbon dioxide-bound carbamate in the absorbent solution that absorbs the carbon dioxide.

Assignees

• Korea Inst Energy Res

Inventors

• Baek Il Hyun
• Nam Sung Chan
• Park Sung Youl

Classifications

• B01D2252/204

  Amines · CPC title

• B01D53/1425 Primary

  Regeneration of liquid absorbents · CPC title

• B01D53/1493

  Selection of liquid materials for use as absorbents · CPC title

• B01D2252/20484

  with one hydroxyl group · CPC title

• B01D2252/20447

  containing a piperazine-ring · CPC title