Method and system for obtaining dimethyl ether from syngas

Patent metadata

Field	Value
Publication number	US-10501394-B2
Application number	US-201515111601-A
Country	US
Kind code	B2
Filing date	Jan 5, 2015
Priority date	Jan 28, 2014
Publication date	Dec 10, 2019
Grant date	Dec 10, 2019

Abstract

A process is proposed for production of dimethyl ether (DME) from synthesis gas (SG), in which at least one feed stream formed from synthesis gas (SG) is subjected to at least one synthesis step, in which components present in the feed stream are at least in part converted to dimethyl ether (DME), wherein at least one crude product stream is obtained which contains at least dimethyl ether (DME) and the unreacted components of the feed stream. The feed stream contains at least hydrogen, carbon monoxide and carbon dioxide, and has a stoichiometric number of 2.0 to 5.0. The feed stream further contains 4 to 20 mol percent carbon dioxide, and the ratio of carbon dioxide to carbon monoxide in the feed stream is in a range from 0.5 to 4. The at least one synthesis step is carried out under isothermal conditions. A system for production of dimethyl ether (DME) from synthesis gas (SG) is likewise subject matter of the present invention.

First claim

What we claim is:

1. A process for production of dimethyl ether from synthesis gas, said process comprising:
subjecting at least one feed stream formed from synthesis gas to at least one synthesis step wherein components present in the at least one feed stream are at least in part converted to dimethyl ether, and
obtaining at least one crude product stream which contains at least dimethyl ether and unreacted components of the at least one feed stream,
wherein said at least one feed stream contains hydrogen, carbon monoxide and carbon dioxide corresponding to a stoichiometric number of 2.1 to 5.0 and contains 4 to 20 mol percent carbon dioxide, and the molar ratio of carbon dioxide to carbon monoxide in the at least one feed stream is in a range from 0.5 to 4,
wherein unreacted components of the at least one feed stream are, at least in part, separated from the crude product stream, and said unreacted components are used together with the synthesis gas to form the at least one feed stream, and
wherein the at least one synthesis step is carried out under isothermal conditions.

2. The process according to claim 1 , wherein in said at least one synthesis step hydrogen, carbon monoxide and/or carbon dioxide are converted to methanol, and the methanol is further converted to dimethyl ether in the presence of other components present in the at least one feed stream.

3. The process according to claim 1 , wherein the unreacted components of the at least one feed stream are added at least in part to a synthesis gas stream as a recycle stream which predominantly contains hydrogen, carbon monoxide and carbon dioxide.

4. The process according to claim 3 , wherein a methanol stream is produced from the crude product stream, and the methanol stream is added at least in part together with the recycle stream to the synthesis gas stream.

5. The process according to claim 1 , wherein the at least one synthesis step is carried out at a temperature level of 190 to 310° C. and at a pressure level of 20 to 100 bar.

6. The process according to claim 1 , wherein, in the at least one synthesis step, at least one catalyst is used to form dimethyl ether from hydrogen and carbon monoxide, and from hydrogen and carbon dioxide via methanol as intermediate.

7. The process according to claim 1 , further comprising separating off water, dimethyl ether, carbon dioxide and/or methanol from the crude product stream.

8. The process according to claim 1 , wherein the at least one synthesis step is carried out at a temperature level of 190 to 310° C.

9. The process according to claim 1 , wherein the at least one synthesis step is carried out at a pressure level of 20 to 100 bar.

10. The process according to claim 1 , wherein the at least one synthesis step is carried out in an isothermally operated cooled fixed-bed reactor.

11. The process according to claim 1 , wherein the molar ratio of carbon dioxide to carbon monoxide in the at least one feed stream is in a range from 0.5 to 2.0.

12. The process according to claim 1 , wherein the molar ratio of carbon dioxide to carbon monoxide in the at least one feed stream is in a range from 0.5 to 1.0.

13. The process according to claim 1 , wherein the molar ratio of carbon dioxide to carbon monoxide in the at least one feed stream is in a range from 1.0 to 1.5.

14. The process according to claim 1 , further comprising subjecting said crude product stream to a separation step wherein a product stream predominantly containing dimethyl ether and a recycle stream of unreacted components of the at least one feed stream are obtained.

15. The process according to claim 1 , further comprising subjecting said crude product stream to a separation step wherein a product stream predominantly containing dimethyl ether, a carbon dioxide-rich stream, and a recycle stream of unreacted components of the at least one feed stream is obtained.

16. The process according to claim 1 , wherein said at least one feed stream contains hydrogen, carbon monoxide and carbon dioxide corresponding to a stoichiometric number of 3.6 to 4.8.

17. The process according to claim 1 , wherein said at least one feed stream contains hydrogen, carbon monoxide and carbon dioxide corresponding to a stoichiometric number of 4.0 to 4.8.

18. The process according to claim 1 , wherein the at least one synthesis step is carried out at a pressure level of greater than 50 bar to 100 bar.

19. A process for production of dimethyl ether from synthesis gas, said process comprising:
subjecting at least one feed stream formed from synthesis gas to at least one synthesis step wherein components present in the at least one feed stream are at least in part converted to dimethyl ether, and
obtaining at least one crude product stream which contains at least dimethyl ether and unreacted components of the at least one feed stream,
wherein said at least one feed stream contains hydrogen, carbon monoxide and carbon dioxide corresponding to a stoichiometric number of 2.1 to 5.0 and contains 4 to 20 mol percent carbon dioxide, and the molar ratio of carbon dioxide to carbon monoxide in the at least one feed stream is in a range from 0.5 to 4, and
wherein the at least one synthesis step is carried out under isothermal conditions in an isothermally operated cooled fixed-bed reactor.

Assignees

• Linde Ag

Inventors

• Fritz Helmut
• Bartesch Thomas
• Delhomme Clara
• Peschel Andreas
• Fendt Johannes
• Klein Harald

Classifications

• C07C41/46

  Use of additives, e.g. for stabilisation · CPC title

• C07C27/06

  by hydrogenation of oxides of carbon · CPC title

• C07C41/01 Primary

  Preparation of ethers · CPC title

• C07C41/09 Primary

  by dehydration of compounds containing hydroxy groups · CPC title

• Y02P20/582

  Recycling of unreacted starting or intermediate materials · CPC title