Complex amine absorbent, and device and method for removing one or both of CO
View Patent ↗An absorbent is prepared by dissolving in water 1) monoethanolamine (MEA) and 2) a primary amine represented by the following formula (1) and having high steric hindrance. Releasability of CO 2 or H 2 S during regeneration of the absorbent is thereby improved, and the amount of water vapor used during regeneration of the absorbent in a facility for recovering CO 2 or H 2 S can be reduced. R 1 to R 3 : H or a hydrocarbon group having 1 to 3 carbon atoms, at least one of R 1 to R 3 being a hydrocarbon.
1. A complex amine absorbent for absorbing one or both of CO 2 and H 2 S in a gas, the complex amine absorbent comprising
1) monoethanolamine (MEA),
2) 2-amino-2-methyl-1-propanol, and
3) at least one selected from the group consisting of N,N′-dimethylethylenediamine, N,N′-diethylethylenediamine, and N,N′-dimethylpropanediamine.
2. The complex amine absorbent according to claim 1 ,
wherein the component 3) is N,N′-dimethylethylenediamine or N,N′-dimethylpropanediamine.
3. A device for removing one or both of CO 2 and H 2 S, the device comprising: an absorber for removing one or both of CO 2 and H 2 S by bringing a gas containing one or both of CO 2 and H 2 S in contact with the complex amine absorbent of claim 1 ; and a regenerator for regenerating a solution containing the one or both of CO 2 and H 2 S absorbed therein, the absorbent regenerated by removing the one or both of CO 2 and H 2 S in the regenerator being reused in the absorber.
4. A method of removing one or both of CO 2 and H 2 S, the method comprising: bringing a gas containing one or both of CO 2 and H 2 S in contact with the complex amine absorbent of claim 1 to remove the one or both of CO 2 and H 2 S; regenerating a solution containing one or both of CO 2 and H 2 S absorbed therein; and reusing, in an absorber, the absorbent regenerated by removing the one or both of CO 2 and H 2 S in a regenerator.
5. The method for removing one or both of CO 2 and H 2 S according to claim 4 ,
wherein an absolute pressure inside the regenerator is 130 to 200 kPa,
an absorption temperature in the absorber is 30 to 80° C., and
a regeneration temperature in the regenerator is 110° C. or higher.