CPC B01D 53/1493 (2013.01) [B01D 53/1425 (2013.01); B01D 53/1475 (2013.01); C07D 295/13 (2013.01); B01D 2252/2041 (2013.01); B01D 2252/20426 (2013.01); B01D 2252/20431 (2013.01); B01D 2252/20452 (2013.01)] | 1 Claim |
1. A method, comprising:
contacting a gas stream comprising a first amount of CO2 with a CO2-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 CO2 that is less than the first amount, and a CO2-rich solvent stream;
heating the CO2-rich solvent stream to a second temperature of 80° C. to 160° C. to form a CO2 stream and regenerate the CO2-lean solvent; and
cooling the regenerated CO2-lean solvent to a temperature of from 30° C. to 60° C. wherein the compound has a structure according to Formula I
R1(R2)N-L1-NH—R3 Formula I
each of R1 and R2 independently is alkyl, cycloalkyl, or R1 and R2 together with the nitrogen to which they are attached, form a heterocyclyl ring;
L1 is C2-4alkyl, or L1 and R1 together with the nitrogen to which they are attached form a 5- or 6-membered heterocyclyl ring; and
R3 is branched C3-6alkyl, 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 CO2-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 R1 and R2 is branched alkyl or cycloalkyl;
ii) R1 forms a heterocyclyl with L1;
iii) R1 and R2 together with the nitrogen to which they are attached, forms a heterocyclyl ring;
iv) at least one of R1 and R2 is not linear alkyl; or
v) R3 is alkoxyalkyl.
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