Integrated capture and conversion of CO
A process for producing methane or methanol includes combining a hydrogenation catalyst, hydrogen, and CO 2 with a condensed phase solution comprising an amine under conditions effective to form methane or methanol, and water. A process for coproduction of methanol and a glycol includes combining an epoxide, a hydrogenation catalyst, hydrogen, and CO 2 with a condensed phase solution comprising an amine under conditions effective to form methanol and a glycol.
1. A process, comprising:
producing methane by combining a hydrogenation catalyst, H 2 , and CO 2 with a condensed phase comprising an amine under conditions effective to provide a reaction between the hydrogen and CO 2 to form methane and water in the condensed phase comprising the amine, wherein at least 10 mol % of the CO 2 is consumed in the reaction; and
separating the methane from the amine and the water.
2. The process of claim 1 , wherein the hydrogenation catalyst comprises Ru, Ni, Fe, Co, Rh, or a combination thereof.
3. The process of claim 2 , wherein the hydrogenation catalyst further comprises an oxide or carbon support on which the metal is disposed.
4. The process of claim 1 , wherein the conditions effective to form methane comprise:
(i) a temperature T M of 100° C. to 200° C.; or
(ii) an initial pressure P M of 0.1 MPa to 10 MPa; or
(iii) a time t M of 3 seconds to 36 hours; or
(iv) any combination of (i), (ii), and (iii).
5. The process of claim 1 , wherein:
(i) a molar ratio of H 2 to CO 2 is from 4:1 to 10:1; or
(ii) the CO 2 is adsorbed, absorbed, covalently bound, or ionically bound to the amine, and the process is performed in an absence of CO 2 overpressure; or
(iii) both (i) and (ii).
6. The process of claim 1 , wherein:
(i) the hydrogenation catalyst is disposed in a fixed bed or fluidized bed; or
(ii) the process is a continuous process; or
(iii) both (i) and (ii).
7. The process of claim 1 , wherein the condensed phase is a condensed phase solution further comprising the CO 2 .
8. The process of claim 7 , further comprising preparing the condensed phase solution by contacting a gas stream comprising CO 2 with an amine-containing solvent or solution prior to combining the epoxide, the hydrogenation catalyst, and the hydrogen with the condensed phase solution.
9. The process of claim 8 , wherein contacting the gas stream with the amine-containing solvent or solution is performed:
(i) at a temperature T′ of 20° C. to 60° C.; or
(ii) at an initial pressure P′ of 0.1 MPa to 5 MPa; or
(iii) both (i) and (ii).
10. The process of claim 1 , wherein:
(i) the amine comprises a 1° amine group, a 2° amine group, a 3° amine group, or any combination thereof; or
(ii) wherein the CO 2 is adsorbed, absorbed, covalently bound, or ionically bound to the amine; or
(iii) both (i) and (ii).
11. The process of claim 10 , wherein the amine comprises a polyamine, a tertiary amine, an aminopyridine, a compound according to Formula I, or any combination thereof, the compound according to Formula I having a structure R 1 (R 2 )N-L 1 -NH—R 3 where each of R 1 and R 2 independently is aliphatic or cycloaliphatic or R 1 and R 2 together with the nitrogen to which they are attached form a heterocyclyl ring, L 1 is aliphatic or cycloaliphatic or L 1 and R 1 together with the nitrogen to which they are attached form a heterocyclic ring, and R 3 is aliphatic, cycloaliphatic, cycloalkylalkyl or alkoxyalkyl.
12. The process of claim 11 , wherein the amine comprises a compound according to Formula I.
13. The process of claim 10 , wherein the amine comprises N-(2-ethoxyethyl)-3-morpholinopropan-1-amine.
14. The process of claim 1 , wherein separating the methane from the amine and the water comprises:
cooling the condensed phase solution comprising the methane, the amine, and the water to a temperature of 20° C. to 50° C.; and
flowing the condensed solution through a vapor-liquid separator, thereby separating the methane from the amine and the water.
15. The process of claim 1 , further comprising:
separating the amine and the water; and
recycling at least a portion of the amine.
16. The process of claim 1 , wherein the H 2 is present in molar excess to the CO 2 , the process further comprising:
separating unreacted H 2 from the methane and the amine; and
recycling at least a portion of the unreacted H 2 .
17. The process of claim 1 , further comprising:
flowing the methane, water, and amine through a steam generator prior to separating the methane from the amine and the water, thereby generating power.
18. The process of claim 1 , wherein the hydrogenation catalyst is disposed in a fixed bed or a fluidized bed.
19. The process of claim 1 , wherein producing methane by combining the hydrogenation catalyst, H 2 , and CO 2 with the condensed phase comprising the amine is a continuous process comprising flowing the H 2 , the CO 2 , and the condensed phase comprising the amine through a fixed or fluidized bed of the hydrogenation catalyst under the conditions effective to provide the reaction between the hydrogen and the CO 2 to form methane and water in the condensed phase comprising the amine.
20. The process of claim 1 , wherein:
the condensed-phase amine comprises N-(2-ethoxyethyl)-3-morpholinopropan-1-amine (EEMPA);
a concentration of CO 2 in the condensed-phase amine is 25 mol % to 50 mol %;
the hydrogenation catalyst comprises 5 wt % Ru/Al 2 O 3 ;
a molar ratio of H 2 to CO 2 is from 4:1 to 10:1; and
the conditions effective to form methane comprise (i) a temperature of 120° C. to 190° C., (ii) a pressure of 1 MPa to 6 MPa, and (iii) a time of 3 hours to 12 hours or a weight hourly space velocity is 0.05 g CO2 /g catalyst h −1 to 0.5 g CO2 /g catalyst h −1 .