Process for production of methane-containing gas mixture

Patent metadata

Field	Value
Publication number	US-9840446-B2
Application number	US-201515303928-A
Country	US
Kind code	B2
Filing date	Mar 20, 2015
Priority date	Apr 16, 2014
Publication date	Dec 12, 2017
Grant date	Dec 12, 2017

Abstract

A process for producing a methane-containing gas mixture includes the steps of:
(i) passing a first feed gas mixture including hydrogen and carbon dioxide through a bed of methanation catalyst to react a portion of the hydrogen with at least a portion of the carbon dioxide and form a methane-containing gas mixture containing residual hydrogen, (ii) adding an oxygen-containing gas to the methane-containing gas mixture containing residual hydrogen to form a second feed gas mixture, and (iii) passing the second feed gas mixture through a bed of an oxidation catalyst to react the residual hydrogen and oxygen to form a hydrogen depleted methane-containing gas mixture.

First claim

The invention claimed is:

1. A process for producing a methane-containing gas mixture comprising the steps of:
(i) passing a first feed gas mixture comprising hydrogen and carbon dioxide through a bed of methanation catalyst to react a portion of the hydrogen with at least a portion of the carbon dioxide and form a methane-containing gas mixture containing residual hydrogen,
(ii) adding an oxygen-containing gas to the methane-containing gas mixture containing residual hydrogen to form a second feed gas mixture, and
(iii) passing the second feed gas mixture through a bed of a selective oxidation catalyst at an inlet temperature in the range 150 to 350° C. to selectively react the residual hydrogen and oxygen to form a hydrogen depleted methane-containing gas mixture.

2. The process according to claim 1 , wherein the hydrogen concentration in the first feed gas mixture is 20% by volume.

3. The process according to claim 1 , wherein the first feed gas mixture is a synthesis gas comprising hydrogen, carbon dioxide and carbon monoxide.

4. The process according to claim 1 , wherein the first feed gas mixture is a prepared by mixing a hydrogen-containing gas mixture with a carbon dioxide-containing gas mixture.

5. The process according to claim 4 , wherein the hydrogen-containing gas mixture is a methane-containing gas mixture.

6. The process according to claim 4 , wherein the first feed gas mixture or hydrogen-containing gas mixture and/or the carbon dioxide-containing gas mixture are subjected to a desulphurisation step prior to the methanation step.

7. The process according to claim 1 , wherein the methanation catalyst is a ruthenium- or nickel-containing methanation catalyst.

8. The process according to claim 1 , wherein the methanation catalyst is operated at an inlet temperature in the range 200 to 350° C.

9. The process according to claim 1 , wherein the temperature of the methane-containing gas mixture containing residual hydrogen is adjusted before mixing it with the oxygen containing gas.

10. The process according to claim 1 , wherein the oxidation catalyst is a supported precious metal oxidation catalyst.

11. The process according to claim 1 , wherein the process is performed at a pressure in the range 5 to 80 bar abs.

12. The process according to claim 1 , wherein the methanation catalyst is operated at an inlet temperature in the range 200 to 300° C.

13. The process according to claim 1 , wherein the methanation catalyst is operated at an inlet temperature in the range 230 to 280° C.

Assignees

• Johnson Matthey Plc

Inventors

• Abbott Peter Edward James

Classifications

• C07C1/04

  from carbon monoxide with hydrogen · CPC title

• C07C2523/755

  Nickel · CPC title

• C10L2290/141

  of additive or catalyst · CPC title

• C10G2/332

  of the iron-group · CPC title

• C07C2523/46

  Ruthenium, rhodium, osmium or iridium · CPC title