Diamine solvent system for CO2 capture

Patent metadata

Field	Value
Publication number	US-11745137-B2
Application number	US-202217584597-A
Country	US
Kind code	B2
Filing date	Jan 26, 2022
Priority date	Mar 25, 2019
Publication date	Sep 5, 2023
Grant date	Sep 5, 2023

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 at a first temperature of from 30° C. to 80° C., to form a treated gas stream comprising a second amount of CO 2 that is less than the first amount, and a CO 2 -rich solvent stream;
heating the CO 2 -rich solvent stream to a second temperature of 80° C. to 160° C. to form a CO 2 stream and regenerate the CO 2 -lean solvent; and
cooling the regenerated CO 2 -lean solvent to a temperature of from 30° C. to 60° C. wherein the compound has a structure according to Formula I
R 1 (R 2 )N-L 1 -NH—R 3   Formula I

each of R 1 and R 2 independently is alkyl, cycloalkyl, or R 1 and R 2 together with the nitrogen to which they are attached, form a heterocyclyl ring;
L 1 is C 2-4 alkyl, or L 1 and R 1 together with the nitrogen to which they are attached form a 5- or 6-membered heterocyclyl ring; and
R 3 is branched C 3-6 alkyl, or alkoxyalkyl;

wherein the compound has a vapor pressure of less than 1 Torr at 40° C. content of less than 0.1 wt %, and has a viscosity of less than 75 cP at a CO 2 -loading of 40 mol % and at a temperature of 40° C.; and
at least one of the following conditions applies
i) at least one of R 1 and R 2 is branched alkyl or cycloalkyl;
ii) R 1 forms a heterocyclyl with L 1 ;
iii) R 1 and R 2 together with the nitrogen to which they are attached, forms a heterocyclyl ring;
iv) at least one of R 1 and R 2 is not linear alkyl; or
v) R 3 is alkoxyalkyl.

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

• B01D53/1493 Primary

  Selection of liquid materials for use as absorbents · CPC title

• B01D53/1425

  Regeneration of liquid absorbents · CPC title

• B01D53/1475

  Removing carbon dioxide · CPC title

• C07D295/13 Primary

  to an acyclic saturated chain · CPC title

• B01D2252/2041

  Diamines · CPC title