Method for preparing methyl mercaptan

Patent metadata

Field	Value
Publication number	US-10689334-B2
Application number	US-201515322387-A
Country	US
Kind code	B2
Filing date	Jun 29, 2015
Priority date	Jul 4, 2014
Publication date	Jun 23, 2020
Grant date	Jun 23, 2020

Abstract

The present invention relates to a method for preparing methyl mercaptan, in batches or continuously, preferably continuously, said method including at least the following steps: a) reacting at least one hydrocarbon feedstock in the presence of hydrogen sulphide (H 2 S) and optionally sulphur (S) such as to form carbon disulphide (CS 2 ) and hydrogen (H 2 ); b) reacting said carbon disulphide (CS 2 ) by hydrogenation in the presence of said hydrogen (H 2 ) obtained in step a) such as to form methyl mercaptan (CH 3 SH), hydrogen sulphide (H 2 S) and possibly hydrogen (H2); c) optionally recirculating said hydrogen sulphide (H 2 S) formed during step b) to step a); and d) recovering the methyl mercaptan.

First claim

The invention claimed is:

1. A process for preparing methyl mercaptan, batchwise or continuously, said process comprising at least the following steps:
a) reacting at least one hydrocarbon charge in the presence of hydrogen sulphide (H 2 S) to form carbon disulphide (CS 2 ) and hydrogen (H 2 ), wherein the molar H 2 S/hydrocarbon charge ratio is between 0.5 and 10, endpoints included,
b) carrying out a hydrogenation reaction of said carbon disulphide (CS 2 ) in the presence of said hydrogen (H 2 ), both obtained in step a), to form methyl mercaptan (CH 3 SH), hydrogen sulphide (H 2 S) and optionally hydrogen (H 2 ),
c) optionally, recycling said hydrogen sulphide (H 2 S) formed in step b) to step a), and
d) recovering the methyl mercaptan.

2. The process according to claim 1 , wherein the hydrocarbon charge is a hydrocarbon charge in gaseous, liquid or solid form and comprises at least one hydrocarbon having a hydrocarbon chain in saturated or unsaturated linear, branched or cyclic form.

3. The process according to claim 1 , wherein the hydrocarbon charge comprises at least one alkane.

4. The process according to claim 1 , wherein the hydrocarbon charge is methane.

5. The process according to claim 1 , wherein the hydrogen sulphide formed in step b) is recycled into step a).

6. The process according to claim 1 , wherein hydrogen is formed in step b) and is reacted with sulphur to form hydrogen sulphide.

7. The process according to claim 1 , wherein step a) is carried out at a reaction temperature between 500° C. and 1300° C.

8. The process according to claim 1 , wherein step b) is carried out at a reaction temperature between 100° C. and 400° C.

9. The process according to claim 1 , wherein the methyl mercaptan is reacted with sulphur to form dimethyl disulphide.

10. The process according to claim 1 , wherein the process is performed continuously.

11. The process according to claim 1 , wherein the hydrocarbon charge is in gaseous form.

12. The process according to claim 1 , wherein the hydrocarbon charge comprises at least one alkane selected from the group consisting of methane, ethane, propane and butane.

13. The process according to claim 1 , wherein the molar H 2 S/hydrocarbon charge ratio is between 1 and 3, endpoints included.

14. The process according to claim 1 , wherein step a) is carried out at a reaction temperature between 700° C. and 1100° C.

15. The process according to claim 1 , wherein step a) is carried out at a reaction temperature between 800° C. and 1000° C.

16. The process according to claim 1 , wherein step b) is carried out at a reaction temperature between 200° C. and 300° C.

17. The process according to claim 1 , wherein all of the hydrogen sulfide consumed in said process is produced in said process.

18. The process according to claim 1 , wherein hydrogen sulfide produced in said process is consumed in said process.

19. The process according to claim 1 , which produces 0.1 kg to 20 kg of methyl mercaptan per hour per liter of catalyst in step b).

20. The process according to claim 1 , conducted in the absence of a purification step between step a) and step b).

21. The process according to claim 1 , wherein the selectivity for methyl mercaptan is 100%.

Assignees

• Arkema France

Inventors

• Fremy Georges
• Barre Patrice
• Raymond Jean-Michel

Classifications

• Y02P20/582

  Recycling of unreacted starting or intermediate materials · CPC title

• C01B32/75 Primary

  Preparation by reacting sulfur or sulfur compounds with hydrocarbons · CPC title

• C07C319/02 Primary

  of thiols · CPC title

• C07C319/24

  by reactions involving the formation of sulfur-to-sulfur bonds · CPC title

• B01J2219/00033

  Continuous processes · CPC title