Diamine solvent system for CO2 capture

Patent metadata

Field	Value
Publication number	US-12290779-B2
Application number	US-202318353338-A
Country	US
Kind code	B2
Filing date	Jul 17, 2023
Priority date	Mar 25, 2019
Publication date	May 6, 2025
Grant date	May 6, 2025

Abstract

Disclosed herein is a method and system for CO 2 removal from a gas stream using a diamine solvent having a Formula I

R 1 (R 2 )N-L 1 -NH—R 3    Formula I.

With respect to Formula I, each of R 1 and R 2 independently is aliphatic, cycloaliphatic, or R 1 and R 2 together with the nitrogen to which they are attached, form a heterocyclyl ring; L 1 is aliphatic, cycloaliphatic, or L 1 and R 1 together with the nitrogen to which they are attached form a heterocyclyl ring; and R 3 is aliphatic, cycloaliphatic, cycloalkylalkyl, or alkoxyalkyl. And/or the compound may have a viscosity of less than 75 cP at a CO 2 -loading of 40 mol % and at a temperature of 40° C.

First claim

We claim:

1. A method, comprising:
contacting a gas stream comprising a first amount of CO 2 with a CO 2 -lean solvent stream comprising a compound according to Formula I, to form a treated gas stream comprising a second amount of CO 2 that is less than the first amount, and to form a CO 2 -rich solvent stream; and
heating the CO 2 -rich solvent stream to form a CO 2 stream and regenerate the CO 2 -lean solvent;

wherein the compound according to Formula I has a structure
R 1 (R 2 )N-L 1 -NH—R 3    Formula I

each of R 1 and R 2 independently is aliphatic, cycloaliphatic, or R 1 and R 2 together with the nitrogen to which they are attached, form a heterocyclyl ring;
L 1 is aliphatic, cycloaliphatic, or L 1 and R 1 together with the nitrogen to which they are attached form a heterocyclyl ring; and
R 3 is aliphatic, cycloaliphatic, cycloalkylalkyl, or alkoxyalkyl; and

wherein
the CO 2 -lean solvent stream consists essentially of the compound of Formula I; and
the compound according to Formula I is not

2. The method of claim 1 , wherein the CO 2 -rich solvent comprises less than 10 wt % water.

3. The method of claim 1 , wherein at least one of R 1 and R 2 is branched alkyl or cycloalkyl.

4. The method of claim 1 , wherein R 1 forms a heterocyclyl with L 1 .

5. The method of claim 1 , wherein R 1 and R 2 together with the nitrogen to which they are attached, forms a heterocyclyl ring.

6. The method of claim 1 , wherein at least one of R 1 and R 2 is not linear alkyl.

7. The method of claim 1 , wherein R 3 is alkoxyalkyl.

8. The method of claim 1 , wherein each of R 1 and R 2 independently is C 1-6 alkyl.

9. The method of claim 1 , wherein R 1 and R 2 together with the nitrogen to which they are attached form a 5- or 6-membered heterocyclyl ring.

10. The method of claim 1 , wherein L 1 is C 2-4 alkyl.

11. The method of claim 1 , wherein L 1 and R 1 together with the nitrogen to which they are attached form a 5- or 6-membered heterocyclyl ring.

12. The method of claim 1 , wherein R 3 is branched C 3-6 alkyl, or alkoxyalkyl.

13. The method of claim 1 , wherein the compound is selected from

14. The method of claim 1 , wherein:
the solvent has a vapor pressure of less than 1 Torr at 40° C. and a residual water content of less than 0.1 wt %;
the solvent has a viscosity of less than 75 cP at a CO 2 -loading of 40 mol % and at a temperature of 40° C.; or
a combination thereof.

15. The method of claim 1 , wherein contacting the gas stream with the CO 2 -lean solvent comprises contacting the gas stream at a first temperature of from 30° C. to 80° C.

16. The method of claim 1 , wherein heating the CO 2 -rich solvent comprises heating the CO 2 -rich solvent to a second temperature of 80° C. to 160° C.

17. The method of claim 1 , further comprising cooling the regenerated CO 2 -lean solvent to a temperature of from 30° C. to 60° C.

Assignees

• Battelle Memorial Institute

Inventors

• Malhotra Deepika
• Koech Phillip K
• Heldebrant David J
• Glezakou Vassiliki-Alexandra
• Rousseau Roger J
• Nguyen Manh Thuong
• Perry Robert
• Page Jordan P
• Cantu David C

Classifications

• B01D53/1425

  Regeneration of liquid absorbents · CPC title

• B01D2252/20426

  Secondary amines · CPC title

• B01D2252/20431

  Tertiary amines · CPC title

• B01D2252/2041

  Diamines · CPC title

• B01D2252/20452

  containing a morpholine-ring · CPC title