Stable silicoaluminophosphate catalysts for conversion of alkyl halides to olefins

Patent metadata

Field	Value
Publication number	US-9550178-B2
Application number	US-201514907598-A
Country	US
Kind code	B2
Filing date	Jul 28, 2015
Priority date	Aug 5, 2014
Publication date	Jan 24, 2017
Grant date	Jan 24, 2017

Abstract

Disclosed is a method for converting an alkyl halide to an olefin. The method includes contacting a silicoaluminophosphate (SAPO) catalyst with a feed that includes an alkyl halide under reaction conditions sufficient to produce an olefin hydrocarbon product that includes C 2 to C 4 olefins. The SAPO catalyst has bimodal acidity designated as weak acid sites and strong acid sites. The weak acid concentration is less than 0.55 mmol/g-cat and the total acid concentration is less than 1.5 mmol/g-cat.

First claim

The invention claimed is:

1. A method for converting an alkyl halide to an olefin, the method comprising contacting a silicoaluminophosphate (SAPO) catalyst with a feed comprising an alkyl halide under reaction conditions sufficient to produce an olefin hydrocarbon product comprising C 2 to C 4 olefins, wherein the SAPO catalyst has bimodal acidity designated as weak acid sites and strong acid sites, wherein the weak acid concentration is less than 0.55 mmol/g-cat and the total acid concentration is less than 1.5 mmol/g-cat.

2. The method of claim 1 , wherein the SAPO catalyst has a weak acid concentration of 0.1 to 0.3 mmol/g-cat and a total acid concentration of less than 0.7 mmol/g-cat.

3. The method of claim 2 , wherein the SAPO catalyst has 1 to 2 wt. % of Si.

4. The method of claim 1 , wherein the SAPO catalyst has a weak acid concentration of 0.3 to 0.5 mmol/g-cat and a total a total acid concentration of 1.3 mmol/g-cat or less.

5. The method of claim 4 , wherein the SAPO catalyst has 3 to 4 wt. % of Si.

6. The method of claim 1 , wherein the SAPO catalyst is SAPO-34.

7. The method of claim 1 , wherein the SAPO catalyst has an average particle size of 0.1 um to 1 μm.

8. The method of claim 1 , wherein the SAPO catalyst has an average pore opening of 3.5 to 4.5 angstroms.

9. The method of claim 1 , wherein the SAPO catalyst has a P content of 17 to 20 wt. % and an Al content of 22 to 24 wt. %.

10. The method of claim 9 , wherein the SAPO catalyst has an Si/(A1+P) ratio of less than 0.17.

11. The method of claim 1 , wherein the alkyl halide conversion is at least 25% at 20 hours of use at a temperature of 300° C. to 375° C. and a WHSV of the halide feed of 0.5 and 1.5 h −1 .

12. The method of claim 11 , wherein the combined selectivity of ethylene and propylene is at least 80%.

13. The method of claim 1 , wherein the SAPO catalyst has a weak acid concentration of 0.50 mmol/g-cat or less and a total acid concentration of 1.3 mmol/g-cat or less.

14. The method of claim 1 , wherein the SAPO catalyst has 4 wt. % or less of Si.

15. The method of claim 1 , wherein the SAPO catalyst deactivation rate is less than 5% alkyl halide conversion decrease per hour.

16. The method of claim 1 , wherein the alkyl halide is a methyl halide, wherein the methyl halide is methyl chloride, methyl bromide, methyl fluoride, or methyl iodide, or any combination thereof.

17. The method of claim 1 , wherein the feed comprises about 10 mol % or more of the alkyl halide.

18. The method of claim 1 , further comprising regenerating the used catalyst after 20 hours of use.

19. The method of claim 1 , wherein the SAPO catalyst has an average particle size of from 0.2 μm to 0.6 μm.

20. The method of claim 1 , wherein the SAPO catalyst has an average particle size of about 0.4 μm.

Assignees

• Sabic Global Technologies Bv

Inventors

• Ghosh Ashim Kumar
• Khanmamedova Alla
• Mier Mike
• Banke Jonathan

Classifications

• C07C2529/85

  Silicoaluminophosphates (SAPO compounds) · CPC title

• Y02P20/584

  Recycling of catalysts · CPC title

• B01J29/85 Primary

  Silicoaluminophosphates [SAPO compounds] · CPC title

• C07C1/26

  starting from organic compounds containing only halogen atoms as hetero-atoms · CPC title

• Y02P20/52

  using catalysts, e.g. selective catalysts · CPC title