Catalyst for the synthesis of alkyl mercaptans and process for producing it

Patent metadata

Field	Value
Publication number	US-9764309-B2
Application number	US-201214365801-A
Country	US
Kind code	B2
Filing date	Nov 27, 2012
Priority date	Dec 19, 2011
Publication date	Sep 19, 2017
Grant date	Sep 19, 2017

Abstract

The present invention relates to a catalyst which comprises a support material and an oxidic composition containing at least one alkali metal and tungsten, a process for producing such catalysts and also a process for preparing alkyl mercaptans by reaction of alkanols with hydrogen sulphide in the presence of such a catalyst.

First claim

The invention claimed is:

1. A process for producing a catalyst comprising a support material, wherein the support material has a particle size from 1-25 μm, and an oxidic composition comprising oxygen together with at least one alkali metal and tungsten, wherein the oxidic composition has a formula A x WO y , wherein A is at least one alkali metal, x is from 0.8 to 2 and represents the mole fraction of the alkali metal to tungsten in the composition, and y is from 3.4 to 4 and represents the mole fraction of oxygen in the composition, the process comprising:
1) mixing of the support material with an oxidic tungsten compound and at least one separate alkali metal compound to obtain a catalyst composition; and
2) shaping of the catalyst composition.

2. The process of claim 1 , wherein the oxidic tungsten compound is selected from the group consisting of tungsten trioxide (WO 3 ), tungstic acid (WO 3 .H 2 O), metatungstic acid, paratungstic acid, isopolytungstic acids, heteropolytungstic acids, ammonium salts thereof, hydrates thereof and mixtures thereof, ammonium orthotungstate, ammonium metatungstate and ammonium paratungstate.

3. The process of claim 1 , wherein at least one alkali metal compound is a basic alkali metal compound.

4. The process of claim 1 , wherein the support material is an oxidic inorganic support material.

5. The process of claim 1 , wherein the oxidic tungsten compound and the separate alkali metal compound are added in succession to the support material.

6. The process of claim 1 , wherein at least one organic and/or inorganic binder is added in one or both of 1) and 2).

7. The process of claim 1 , wherein the shaping of the catalyst is carried out by extrusion or pressing.

8. The process of claim 3 , wherein the basic alkali metal compound is selected from the group consisting of a hydroxide of an alkali metal and a carbonate of an alkali metal.

9. The process of claim 4 , wherein the support material is selected from the group consisting of aluminium oxide, silicon dioxide, titanium dioxide, zirconium oxide, and amorphous aluminosilicates and mixtures thereof.

10. The process of claim 5 , wherein the oxidic tungsten compound is added as a solid to the support material or to the mixture of support material and a least one alkali metal compound.

11. The process of claim 7 , further comprising:
(i) drying of the catalyst composition and/or of the shaped catalyst; and
(ii) calcination of the catalyst composition and/or of the shaped catalyst.

12. A catalyst, comprising:
a support material having a particle size from 1-25 μm; and
an oxidic composition comprising oxygen together with at least one alkali metal and tungsten, wherein the oxidic composition has a formula A x WO y , wherein A is at least one alkali metal, x is from 0.8 to 2 and represents the mole fraction of the alkali metal to tungsten in the composition, and y is from 3.4 to 4 and represents the mole fraction of oxygen in the composition.

13. The catalyst of claim 12 , wherein the catalyst is produced by a process comprising:
mixing a solid tungsten compound with the support material.

14. The catalyst of claim 12 , wherein the proportion of the oxidic composition composed of alkali metal and tungsten in the catalyst is greater than 15% by weight, based on the total weight of the catalyst.

15. The catalyst of claim 12 , wherein the support material comprises at least one oxidic inorganic compound.

16. The catalyst of claim 12 , which further comprises at least one organic and/or inorganic binder.

17. The catalyst of claim 12 , wherein a standard deviation, stadev, of the normalized tungsten concentration, c norm (W), over the cross section of the catalyst is less than 20, determined by quantitative EDX analysis in accordance with ISO 22309 (2006) in square measurement spots, which have a side length of 100 μm in each case and whose midpoints lie on a straight line and are in each case 100 μm from the midpoint of the adjoining square, with the first and last midpoint of a square being in each case 100 μm from the edge of the catalyst cross section.

18. A catalyst comprising, based on a total weight of the catalyst:
from 25% to 50% by weight of a support material having a particle size from 1-25 μm; and
greater than 40% by weight of an oxidic composition comprising oxygen together with at least one alkali metal and tungsten.

Assignees

• Fonfe Benjamin
• Fuss Sebastian
• Wilz Frank
• Jakob Harald
• Weckbecker Christoph
• Evonik Degussa Gmbh

Inventors

• Fonfe Benjamin
• Fuss Sebastian
• Wilz Frank
• Jakob Harald
• Weckbecker Christoph

Classifications

• B01J37/0205

  in several steps · CPC title

• B01J37/0036

  Grinding · CPC title

• B01J23/30 Primary

  Tungsten · CPC title

• C07C319/08

  by replacement of hydroxy groups or etherified or esterified hydroxy groups · CPC title

• C07C319/02

  of thiols · CPC title