Process for the preparation of tertiary olefins

• US 5,227,564 A
• Filed: 12/09/1991
• Issued: 07/13/1993
• Est. Priority Date: 12/09/1991
• Status: Expired due to Fees

• Current Assignee: Daiken Corporation
• Original Assignee: Daiken Corporation
• Inventors: Wang, Shing Y., Sheu, Liang, Lin, F. S., Chu, C. C., Chen, S. C.
• Primary Examiner(s): Pal, Asok
• Assistant Examiner(s): ACHUTAMURTHY, PONNATHAPURA N
• Application Number:
  US07/804,002
• Time in Patent Office: 582 Days
• Field of Search: 585/640, 585/639
• US Class Current: 585/640
• CPC Class Codes: C07C 1/20 starting from organic compounds containing only oxygen atoms as heteroatoms
• CPC Class Codes: C07C 11/02 Alkenes
• CPC Class Codes: C07C 2529/40 of the pentasil type, e.g. types ZSM-5, ZSM-8 or ZSM-11
• CPC Class Codes: C07C 2529/44 Noble metals
• CPC Class Codes: C07C 2529/65 of the ferrierite type, e.g. types ZSM-21, ZSM-35 or ZSM-38
• CPC Class Codes: C07C 2529/67 Noble metals
• CPC Class Codes: C07C 2529/70 of types characterised by their specific structure not provided for in groups C07C2529/08 - C07C2529/65
• CPC Class Codes: C07C 2529/74 Noble metals

Abstract

A process for the preparation of tertiary olefins by decomposition of a tertiary alkyl ether in the vapor phase in the presence of a catalyst, wherein the catalyst used is a composition of: (i) 5 to 95 percent by weight of a crystalline aluminosilicate zeolite having a silica-to-alumina mole ratio of at least about 5 and a Constraint Index of about 1 to about 12, and (ii) 95 to 5 percent by weight of a binder selected from amorphous silica, alumina, silica-alumina and mixtures thereof.

Claims

1. A process for the production of a tertiary olefin and an alcohol by decomposition of the corresponding tertiary alkyl ether in the vapor phase at a temperature of about 120°

to about 300°

C. and a pressure of about 1 to about 10 atmospheres in the presence of a catalyst composition comprising;

(i) 5 to 95 percent by weight of a crystalline alumina silicate zeolite having a silica-to-alumina mole ratio of about 15 to about 500 and a Constraint Index of about 1 to about 12, and

(ii) 95 to 5 percent by weight of a binder selected from amorphous silica, alumina, silica-alumina, and mixtures thereof, and wherein;

conversion of such tertiary alkyl ether is at least 94 mole %, and selectivity towards production of said tertiary olefin is at least 99 mole % and towards production of said alcohol is at least 96 mole %.

2. A process according to claim 1 wherein the crystalline aluminosilicate zeolite is ZSM-5, ZSM-11, ZSM-5/ZSM-11 intermediate, ZSM-12, ZSM-22, ZSM-23, ZSM-35, ZSM-38, ZSM-48 or ZSM-50 and mixtures thereof.

3. A process according to claim 2 wherein said zeolite is ZSM-5 or HZSM-5.

4. A process according to claim 1 wherein the binder is amorphous silica.

5. A process according to claim 1 wherein the catalyst also includes a catalytic metal of Group VIII of the Periodic Table.

6. A process according to claim 5 wherein the catalytic metal is Pt or Pd, or mixtures thereof.

7. A process according to claim 1 wherein the tertiary alkyl ether has the formula:

##STR2## wherein R₁, R₂ and R₃ is the same or different, are alkyl groups straight or branched chain having 1 to 4 carbon atoms, and R₄ is an alkyl group, straight or branched chain, having from 1 to 6 carbon atoms.

8. A process according to claim 7 wherein R₁, R₂ and R₃ are alkyl groups having from 1 to 2 carbon atoms, and R₄ is an alkyl group having from 1 to 4 carbon atoms.

9. A process according to claim 1 wherein the tertiary olefin is isobutylene.

10. A process according to claim 1 wherein said tertiary olefin is isoamylene.

11. A process according to claim 7 wherein the tertiary alkyl ether is methyl tertiary butyl ether, methyl tertiary amyl ether, ethyl tertiary butyl ether, or mixtures thereof.

12. A process according to claim 11 wherein said the tertiary alkyl ether is methyl tertiary butyl ether.

13. A process according to claim 11 wherein the tertiary alkyl ether is methyl tertiary amyl ether.

14. A process according to claim 1 wherein the reaction is carried out in a fixed, fluidized or moving bed reactor.

15. A process according to claim 14 wherein said the reaction is carried out in a fixed bed reactor.

16. A process according to claim 2 wherein:

(i) the zeolite comprises 40 to 95 percent by weight, and

(ii) the binder comprises 60 to 5 percent by weight of the catalyst composition.