Compositions and methods for carbon dioxide capture

Patent metadata

Field	Value
Publication number	US-12458920-B2
Application number	US-202217815394-A
Country	US
Kind code	B2
Filing date	Jul 27, 2022
Priority date	Apr 27, 2018
Publication date	Nov 4, 2025
Grant date	Nov 4, 2025

Abstract

An aqueous solvent composition is provided, comprising a nucleophilic component having one or more sterically unhindered primary or secondary amine moieties, a Brønsted base component having one or more basic nitrogen moieties, a water-soluble organic solvent, and water. A biphasic composition is provided, comprising one or more carbamate compounds, one or more conjugate acids of Brønsted base, a water-soluble organic solvent, and water. A biphasic CO 2 absorption process is also provided, utilizing the biphasic solvent composition.

First claim

What is claimed is:

1 . A biphasic composition comprising:
a) at least one carbamate compound comprising a carbamate moiety of a primary amine or a secondary amine; b) a Brønsted base wherein the Brønsted base is in the form of its conjugate acid, wherein the Brønsted base does not form a carbamate moiety with carbon dioxide; c) about 5% to about 50% by weight of a water-soluble organic solvent, wherein the organic solvent comprises a glyme; and d) about 5% to about 40% by weight of water; wherein the biphasic composition has a CO 2 -rich phase and a CO 2 -lean phase; wherein the rich phase comprises the highest % weight of water, the highest % weight of the carbamate compound, and the highest % weight of the conjugate acid; and the lean phase comprises the highest % weight of the organic solvent.

2 . The biphasic composition of claim 1 wherein the organic solvent comprises triglyme, tetraglyme, or a combination thereof.

3 . The biphasic composition of claim 1 wherein the water-soluble organic solvent is about 30% to about 50% by weight of the biphasic composition.

4 . The biphasic composition of claim 1 wherein the water is about 20% to about 40% by weight of the biphasic composition.

5 . The biphasic composition of claim 1 wherein the composition comprises about 0.5 mole equivalents to about 3 mole equivalents of the carbamate moiety per liter of the biphasic composition.

6 . The biphasic composition of claim 1 wherein the CO 2 -rich phase comprises about 0.5 mole equivalents to about 6.5 mole equivalents of carbamate moieties per liter of the CO 2 -rich phase.

7 . The biphasic composition of claim 1 wherein the Brønsted base comprises an imidazole in the form of its conjugate acid.

8 . The biphasic composition of claim 1 wherein the Brønsted base is 2-ethyl-4-methylimidazole in the form of its conjugate acid.

9 . The biphasic composition of claim 1 wherein the primary amine of the carbamate moiety is a sterically unhindered primary amine or the secondary amine of the carbamate moiety is a sterically unhindered secondary amine.

10 . The biphasic composition of claim 1 wherein the carbamate moiety comprises the secondary amine and the secondary amine is piperazine or 2-methylpiperazine.

11 . The biphasic composition of claim 1 wherein the carbamate moiety comprises piperazine and the biphasic composition comprises a second carbamate moiety comprising 2-methylpiperazine.

12 . The biphasic composition of claim 1 wherein the composition further comprises a gas comprising about 96% by volume oxygen and about 4% by volume carbon dioxide.

13 . The biphasic composition of claim 1 wherein the composition further comprises one or more metal catalysts.

14 . The biphasic composition of claim 1 wherein the composition oxidatively degrades at a loss-rate of less than 10% by weight in 10 days at 50° C.

15 . The biphasic composition of claim 1 wherein the composition is about 2-fold to about 4-fold less corrosive to carbon-steel than a 30% by weight monoethanolamine (MEA) aqueous solution when the composition and MEA are under absorption conditions at about 40° C. or desorption conditions at 120° C. to 150° C.

Assignees

• Univ Illinois

Inventors

• Lu Yongqi
• Du Yang
• Ye Qing

Classifications

• C07C211/03

  Monoamines · CPC title

• B01D2257/504

  Carbon dioxide · CPC title

• B01D2252/504

  Mixtures of two or more absorbents · CPC title

• B01D2252/20484

  with one hydroxyl group · CPC title

• B01D2252/2041

  Diamines · CPC title