METHOD AND APPARATUS FOR CO CONVERSION TO METHANE

• US 3,766,027 A
• Filed: 02/04/1972
• Issued: 10/16/1973
• Est. Priority Date: 02/04/1972
• Status: Expired due to Term

• Current Assignee: Derek P. Gregory
• Original Assignee: Derek P. Gregory
• Inventors: Gregory, Derek P.
• Primary Examiner(s): Edmundson, F. C.
• Application Number:
  US05/223,546
• Time in Patent Office: 620 Days
• Field of Search: 204/73R,75,76
• US Class Current: 205/349
• CPC Class Codes: C07C 1/12 from carbon dioxide with hydrogen
• CPC Class Codes: C07C 9/04 Methane production by treatment of sewage C02F11/04; natural gas, synthetic natural gas C10L3/06
• CPC Class Codes: C10L 3/08 Production of synthetic natural gas

Abstract

A process of fixation and conversion of carbon dioxide from the atmosphere or other sources to produce methane and oxygen. Carbon dioxide is scrubbed from a CO2-containing source and separated by process of chemical concentration. A special cell is provided in which hydrogen is produced and reacted with the separated CO2 at methanation conditions to produce methane.

Claims

2. A process of claim 1 wherein the carbon dioxide selective sorbent is selected from a. molecular sieves, b. aqueous solutions of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, c. monoethanolamine, diethanolamine, triethanolamine, methyl-2-pyrrolidone, d. diamino isopropanol, methanol and e. mixtures thereof.

3. A process of claim 2 wherein the carbon dioxide selective sorbent is selected from mono-, di-, and triethanolamine, methyl-2-pyrrolidone, and methanol.

4. A process of claim 1 which includes the added step of transferring the exothermic heat of reaction produced in said reaction zone to said desorption zone to selectively effect desorption.

5. A process as in claim 3 which includes the steps of:

g. passing said carbon dioxide-containing sorbent produced in step (a) into a desorption zone to effect desorption therein, and h. recycling said regenerated sorbent into contact with said air to effect resorption of carbon dioxide.

6. A process as in claim 1 which includes the step of:

g. passing a portion of said methane-containing gas mixture to the desorption zone as said oxygen-free gaseous stream to effect said desorption.

7. A process as in claim 1 wherein said step (f) of methane recovery includes the step of separation of water from said methane-containing gas mixture, and which includes the added step of:

g. recycling said water to said electrochemical reaction zone.

8. A process as in claim 1 wherein said step (f) of methane recovery from said methane-containing gas mixture includes separation therefrom of residual CO2, H2 and CO produced in said methanation zone.

9. A process as in claim 8 wherein said residual CO2 and H2 are recycled to said methanation zone.

10. A process as in claim 8 wherein said residual CO2 and H2 are recycled to said desorption step (b) as said oxygen-free gaseous desorption stream.

11. A process as in claim 1 wherein said desorption step (b) is maintained at a temperature within the range of from about 100* to 1,000* F.

12. A process as in claim 1 wherein said electrolysis methanation step (d) is maintained at a temperature within the range of from about 250* to 2,000* F.

13. A process as in claim 1 which includes the step of:

g. passing said recovered methane to said desorption zone to effect said desorption.

14. A process as in claim 1 wherein said reaction zone utilizes an electrolyte selected from an acid, a carbonate or a solid oxide.

15. A process as in claim 1 wherein said gas is air.

16. A process as in claim 1 wherein said gas is process flue gas relatively rich in CO2.