Regenerable solvent mixtures for acid-gas separation

Patent metadata

Field	Value
Publication number	US-10960345-B2
Application number	US-201816058395-A
Country	US
Kind code	B2
Filing date	Aug 8, 2018
Priority date	Mar 2, 2012
Publication date	Mar 30, 2021
Grant date	Mar 30, 2021

Abstract

A solvent system for the removal of acid gases from mixed gas streams is provided. Also provided is a process for removing acid gases from mixed gas streams using the disclosed solvent systems. The solvent systems may be utilized within a gas processing system.

First claim

The invention claimed is:

1. A solvent system comprising a solution formed of a first nucleophilic amine, in combination with a second nucleophilic amine and two or more non-aqueous liquids, wherein the solvent system is in the form of an ionic liquid; wherein the solvent system reacts with an acidic gas so as to form a carbamate, a mixed carbamate, a sulfamic acid, a sulfate salt, or a combination thereof.

2. The solvent system of claim 1 , wherein the first nucleophilic amine is hydrophobic.

3. The solvent system claim 1 , wherein the solvent system is immiscible with water.

4. The solvent system of claim 1 , wherein the solvent system has a solubility with water of less than about 20 g of solvent per 100 mL of water.

5. The solvent system of claim 1 , wherein the acidic gas comprises CO 2 , SO 2 or a combination thereof.

6. The solvent system of claim 1 , wherein the two or more nucleophilic amines are alkyl fluoroaromatic amines.

7. The solvent system of claim 6 , wherein the alkyl fluoroaromatic amines are selected from the group consisting of 3-fluoro-N-methylbenzylamine, 4-fluoro-N-methylbenzylamine, 2-fluorophenethylamine, 3-fluorophenethylamine, and 4-fluorophenethylamine.

8. The solvent system of claim 6 , wherein the two or more non-aqueous liquids are selected from the group consisting of 2,2,3,3,4,4,5,5-octafluoropentanol, 2,2,3,3,4,4-hexafluorobutanol, and 4,4,5,5,6,6,7,7,7-nonafluoroheptanol.

9. The solvent system of claim 1 , wherein the solvent system further comprises one or more additional nucleophilic amines.

10. The solvent system of claim 1 , wherein the first nucleophilic amine and/or the second nucleophilic amine has a pKa of about 8 to about 11 and wherein at least one of the two or more non-aqueous liquids have a pKa of about 10 to about 12.

11. The solvent system of claim 10 , wherein the first nucleophilic amine and/or the second nucleophilic amine has a pKa of about 9.55 to about 11.

12. The solvent system of claim 10 , wherein the first nucleophilic amine and/or the second nucleophilic amine has a pKa of about 10 to about 11.

Assignees

• Res Triangle Inst

Inventors

• Lail Marty
• Coleman Luke

Classifications

• B01D2252/30

  Ionic liquids and zwitter-ions · CPC title

• B01D53/485

  containing only one sulfur compound other than sulfur oxides or hydrogen sulfide · CPC title

• B01D2258/0283

  Flue gases · CPC title

• B01D53/1456 Primary

  Removing acid components · CPC title

• B01D2257/302

  Sulfur oxides · CPC title