MIXED OXIDE COMPOSITIONS AND PROCESS FOR PREPARING ISOOLEFINS

• US 20140087940A1
• Filed: 03/07/2012
• Published: 03/27/2014
• Est. Priority Date: 03/16/2011
• Status: Active Grant

• Current Assignee: Evonik Oxeno GmbH & Company KG
• Original Assignee: Evonik Degussa GmbH
• Inventors: Winterberg, Markus, Maschmeyer, Dietrich, Zanthoff, Horst-Werner, Quandt, Thomas, Bing, Christian, Nau, Asli, Schulze Isfort, Christian
• Granted Patent: US 9,371,255 B2
• Time in Patent Office: Days
• US Class Current: 502/243
• CPC Class Codes: B01J 21/12 Silica and alumina
• CPC Class Codes: B01J 23/002 Mixed oxides other than spinels, e.g. perovskite
• CPC Class Codes: B01J 23/04 Alkali metals
• CPC Class Codes: B01J 2523/00 Constitutive chemical elements of heterogeneous catalysts
• CPC Class Codes: B01J 2523/12 Sodium
• CPC Class Codes: B01J 2523/31 Aluminium
• CPC Class Codes: B01J 2523/41 Silicon
• CPC Class Codes: B01J 2523/51 Phosphorus
• CPC Class Codes: B01J 27/16 containing oxygen , i.e. acids, anhydrides and their derivates with N, S, B or halogens without carriers or on carriers based on C, Si, Al or Zr; also salts of Si, Al and Zr
• CPC Class Codes: B01J 27/1806 with alkaline or alkaline earth metals
• CPC Class Codes: B01J 35/30 characterised by their physical properties
• CPC Class Codes: B01J 35/396 Distribution of the active metal ingredient
• CPC Class Codes: B01J 35/613 10-100 m2/g
• CPC Class Codes: B01J 35/615 100-500 m2/g
• CPC Class Codes: B01J 37/10 in the presence of water, e.g. steam
• CPC Class Codes: B01J 37/28 Phosphorising
• CPC Class Codes: C07C 1/213 by splitting of esters
• CPC Class Codes: C07C 1/22 by reduction
• CPC Class Codes: C07C 11/09 Isobutene
• CPC Class Codes: C07C 2521/08 Silica
• CPC Class Codes: C07C 2523/04 : Alkali 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 29/00 : Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring
• CPC Class Codes: Y02P 20/52 : using catalysts, e.g. selective catalysts
• CPC Class Codes: Y02P 20/582 : Recycling of unreacted starting or intermediate materials

Abstract

The present invention relates to mixed oxide compositions, to the use thereof as a catalyst for cleavage of alkyl tert-alkyl ethers or tertiary alcohols, and to a process for cleaving alkyl tert-alkyl ethers or tertiary alcohols to isoolefins and alcohol or water.

Claims

1. A mixed oxide composition, comprising:

a silicon-aluminium mixed oxide powder, present predominantly or completely as an aggregated primary particles, and an alkali metal or alkaline earth metal oxide,

wherein a weight ratio (Al₂O₃/SiO₂)_ttl in the primary particles is from 0.002 to 0.05,

a weight ratio (Al₂O₃/SiO₂)_surface of the primary particles in a layer close to a surface and having a thickness of approximately 5 nm is less than in the primary particles overall and

a BET surface area of the primary particles is from 50 to 250 m²/g.

2. The mixed oxide composition according to claim 1, obtained by a process comprising treating with an aqueous alkali metal or alkaline earth metal hydroxide solution,

wherein a pH is from 5 to 6.5.

6. The mixed oxide composition according to claim 1, suitable for adding with binders, temporary assistants, and fixatives, thereby producing shaped bodies in a shaping process.

8. A process, comprising:

cleaving a starting compound of formula II;

9. The process according to claim 8,

wherein the catalyst is a mixed oxide composition obtained by a process comprising flame hydrolysis, and has the following a composition:

silicon;

50-99.9% by mass, calculated as SiO₂,

aluminium;

0.1-50% by mass, calculated as Al₂O₃,

alkali metal;

0-15% by mass, calculated as M₂O, or alkaline earth metal;

0-30% by mass, calculated as MO.

10. The process according to claim 8, wherein the starting compound is methyl tert-butyl ether.

11. The process according to claim 8, wherein the starting compound is tert-butyl alcohol.

12. The process according to claim 11, wherein the starting compound is tert-butanol in an azeotropic mixture with water.

13. The process according to claim 8, wherein the cleaving is at a temperature of from 110 to 450°

C.

14. The process according to claim 8, wherein the cleaving is at a pressure of from 0.1 to 2 MPa(abs).

3. A mixed oxide composition, comprising:

a silicon-aluminium mixed oxide powder, present predominantly or completely as aggregated primary particles,

wherein a weight ratio (Al₂O₃/SiO₂)_ttl in the primary particles is from 0.002 to 0.05,

a weight ratio (Al₂O₃/SiO₂)_surface of the primary particles in a layer close to a surface and having a thickness of approximately 5 nm is less than in the primary particles overall,

a BET surface area of the primary particles is from 50 to 250 m²/g, and

the composition is obtained by a process comprising treating with acidic aqueous solution, wherein a pH is within a range from 0 to 6.

4. The mixed oxide composition according to claim 3, wherein the treating comprises adjusting the pH with a phosphorus source.

5. The mixed oxide composition according to claim 4, wherein the phosphorus source is selected from the group consisting of phosphoric acid, phosphonic acid, phosphinic acid, polyphosphoric acid, and dihydrogenphosphate.

15. A process, comprising:

cleaving a starting compound of formula II;

16. The process according to claim 15,

wherein the catalyst is a mixed oxide composition obtained by a process comprising flame hydrolysis, and has a composition:

silicon;

50-99.9% by mass, calculated as SiO₂,

aluminium;

0.1-50% by mass, calculated as Al₂O₃,

alkali metal;

0-15% by mass, calculated as M₂O, or alkaline earth metal;

0-30% by mass, calculated as MO.

7. (canceled)