Spray process for the recovery of CO
View Patent ↗A method for recovering carbon dioxide (CO 2 ) from a gas stream is disclosed. The method includes the step of reacting CO 2 in the gas stream with fine droplets of a liquid absorbent, so as to form a solid material in which the CO 2 is bound. The solid material is then transported to a desorption site, where it is heated, to release substantially pure CO 2 gas. The CO 2 gas can then be collected and used or transported in any desired way. A related apparatus for recovering carbon dioxide (CO 2 ) from a gas stream is also described herein.
1. A method for recovering carbon dioxide (CO 2 ) from a gas stream, comprising the following steps:
a) reacting CO 2 in the gas stream with fine droplets of a liquid absorbent, so as to form a solid material in which the CO 2 is bound;
b) transporting the solid material to a desorption site;
c) heating the solid material in the desorption site, to release substantially pure CO 2 gas; and
d) collecting the CO 2 gas.
2. The method of claim 1 , wherein reaction of the CO 2 with the fine droplets occurs in a spray tower, or in a venturi scrubber.
3. The method of claim 1 , wherein the fine droplets are formed by a spray atomization technique.
4. The method of claim 1 , wherein the fine droplets have an average diameter no greater than about 1000 microns.
5. The method of claim 4 , wherein the fine droplets have an average diameter in the range of about 500 microns to about 1000 microns.
6. The method of claim 1 , wherein the solid material comprises solid particles, having a density of at least about 1.1 g/cc.
7. The method of claim 6 , wherein the solid particles have an average particle size in the range of about 1000 microns to about 2000 microns.
8. The method of claim 1 , wherein the liquid absorbent comprises at least one amine compound.
9. The method of claim 8 , wherein the amine compound is selected from the group consisting of polyimines; polyamines; cyclic amines; guanidines; amidines; hindered amines; amino acids; amino-siloxane compounds, and combinations thereof.
10. The method of claim 9 , wherein the polyimine comprises polyethyleneimine.
11. The method of claim 9 , wherein the cyclic amine is selected from the group consisting of 4-aminopyridine; 1,5-diazabiciclo[4.3.0]non-5-ene (DBN); and 1,8-diazabiciclo[5.4.0]undec-7-ene (DBU).
12. The method of claim 9 , wherein the amidine comprises formamidine (HC(═NH)NH 2 ).
13. The method of claim 9 , wherein the hindered amine is selected from the group consisting of 2,2,6,6-tetramethyl piperidine; tert-butylamine; cyclohexyldiamine; 2-(dimethylamino)-ethanol; 2-(diethylamino)-ethanol; 2-(ethylmethylamino)-ethanol; 1-(dimethylamino)-ethanol; 1-(diethylamino)-ethanol; 1-(ethylmethylamino)-ethanol; 2-(diisopropylamino)-ethanol; 1-(diethylamino)-2-propanol; 3-(diethylamino)-1-propanol; and combinations thereof.
14. The method of claim 9 , wherein the amino-siloxane compound is
(NH 2 C 3 H 6 Si(Me) 2 OSiMe 2 C 3 H 6 NH 2 ),
wherein “Me” is a methyl group.
15. The method of claim 9 , wherein reaction between the liquid absorbent and the amine compound results in the formation of a carbamate, a bicarbonate, or combinations thereof.
16. The method of claim 1 , wherein heating step (c) regenerates at least a portion of the liquid absorbent, which is separated from the collected CO 2 gas.
17. The method of claim 16 , wherein heating step (c) is carried out in a chamber adapted to apply heat to the solid material in which the CO 2 is bound; or in an extruder.
18. The method of claim 16 , wherein the regenerated liquid absorbent is directed back to a reaction site for reaction with additional CO 2 from the gas stream, to form additional solid material.
19. The method of claim 16 , wherein the reaction site comprises a spray tower or a venturi scrubbing system.
20. The method of claim 18 , wherein the regenerated liquid absorbent is directed back to the reaction site by a pumping means or pressure means.
21. The method of claim 1 , wherein heating step (c) is carried out at a temperature sufficient to substantially decompose the solid material formed by the reaction of the CO 2 and the liquid absorbent.
22. The method of claim 1 , wherein reaction step (a) forms CO 2 -lean flue gas.
23. The method of claim 22 , wherein the CO 2 -lean flue gas contains volatile liquid absorbent, and the volatile liquid absorbent is condensed and directed back to a storage chamber, or to a reaction site for reaction with additional CO 2 .
24. The method of claim 1 , wherein the source of the gas stream is selected from the group consisting of a combustion process; a gasification process; a landfill; a furnace; a steam generator, a boiler, and combinations thereof.
25. The method of claim 24 , wherein the source of the gas stream is a coal-fired power plant.
26. The method of claim 1 , wherein the substantially pure CO 2 gas released in step (c) is sequestered in a separate location.
27. A method for recovering carbon dioxide (CO 2 ) from a gas stream which originates at a coal-fired power plant or a gasification plant, comprising the following steps:
A) reacting the CO 2 with fine droplets of a liquid absorbent in a spray tower or in a venturi scrubber, so as to form a solid material in which the CO 2 is bound;
B) transporting the solid material to a desorption chamber;
C) heating the solid material in the desorption chamber, to release substantially pure CO 2 gas; and to regenerate at least a portion of the liquid absorbent;
D) collecting the CO 2 gas; and
E) directing the regenerated liquid absorbent back to the spray tower or venturi scrubber.