Method for the production of a titanium-containing zeolite

• US 6,841,144 B2
• Filed: 02/24/2001
• Issued: 01/11/2005
• Est. Priority Date: 03/02/2000
• Status: Expired due to Term

• Current Assignee: Evonik Degussa GmbH (Rag-Stiftung)
• Original Assignee: Degussa AG (Rag-Stiftung)
• Inventors: Kneitel, Dieter, Hasenzahl, Steffon, Heyne, Klaus
• Primary Examiner(s): SAMPLE, DAVID R
• Application Number:
  US10/220,577
• Publication Number:
  US 20030103894A1
• Time in Patent Office: 1,417 Days
• Field of Search: 423/713, 423/326, 423/716, 502/242, 549/531
• US Class Current: 423/713
• CPC Class Codes: B01J 29/89 Silicates, aluminosilicates or borosilicates of titanium, zirconium or hafnium B01J29/005 takes precedence
• CPC Class Codes: C01B 37/005 Silicates, i.e. so-called metallosilicalites or metallozeosilites
• CPC Class Codes: C07D 301/12 with hydrogen peroxide or inorganic peroxides or peracids

Abstract

The present invention concerns a method for the production of a titanium-containing zeolite whereby a synthesis gel is formed by combining and hydrolysing a hydrolysable silicon compound, a hydrolysable titanium compound and a basic quaternary ammonium compound in an aqueous medium, in quantities such that relative to the starting compounds the molar ratio of Si/Ti is greater than or equal to 30 and that of N/Si is 0.12 to less than 0.20, and the synthesis gel is then crystallised at a temperature of 150 ° C. to 220 ° C. for a period of less than 3 days, and a titanium-containing zeolite obtainable by this method.

Claims

1. A method for the production of a titanium-containing zeolite, comprising forming a synthesis gel by combining and hydrolyzing a hydroyzable silicon compound, a hydrolysable titanium compound and a basic quaternary ammonium compound, as starting compounds in an aqueous medium as a reactive mixture, in quantities such that relative to the starting compounds the molar ratio of Si/Ti is greater than or equal to 30, the molar ratio of H₂O/Si is 10 to 20 and the molar ratio of N/Si is 0.12 to less than 0.20, and crystallizing the synthesis gel in a crystallization stage at a temperature of 150°

C. to 220°

C. for a period of less than 3 days.

2. The method according to claim 1, wherein the molar ratio of N/Si is 0.12 to less than 0.17.

3. The method according to claim 2, wherein the hydrolyzable silicon compound is a tetraalkyl orthosilicate, and the hydrolysable titanium compound is a tetraalkyl orthotitanate.

4. The method according to claim 1, wherein the molar ratio of H₂O/Si is 12 to 17.

5. The method according to claim 4, wherein the hydrolyzable silicon compound is a tetraalkyl orthosilicate, and the hydrolysable titanium compound is a tetraalkyl orthotitanate.

6. The method according to claim 1, wherein the hydrolyzable silicon compound is a tetraalkyl orthosilicate, and the hydrolysable titanium compound is a tetraalkyl orthotitanate.

7. The method according to claim 6, wherein the hydrolysis of the hydrolysable titanium and silicon compounds is supported by distilling off resulting alcohols and optionally replacing a volume of alcohol removed by distillation at least in part by the addition of water to the reaction mixture.

8. The method according to claim 7, wherein the quaternary ammonium compound is a tetraalkyl ammonium hydroxide.

9. Titanium-containing zeolite produced by the method according to claim 6 having a primary crystallite size of 0.2 to 2.0 μ

m.

10. A method for the epoxidation of olefins comprising reacting an olefin with aqueous hydrogen peroxide in a solvent miscible with water in the presence of a catalyst which is the titanium-containing zeolite according to claim 9.

11. The method according to claim 1, wherein the quaternary ammonium compound is a tetraalkyl ammonium hydroxide.

12. The method according to claim 1, wherein the quaternary ammonium compound is a tetra-n-propyl ammonium hydroxide.

13. The method according to claim 1, wherein a crystal suspension is formed in the crystallization stage.

14. The method according to claim 13, further comprising adjusting pH value of the crystal suspension from the crystallization stage to a value of 7 to 10.

15. The method according to claim 1, further comprising separating off the titanium-containing zeolite, drying and calcining said titanium-containing zeolite.

16. Titanium-containing zeolite produced by the method according to claim 15 having a primary crystallite size of 0.2 to 2.0 μ

m.

17. A method for the epoxidation of olefins comprising reacting an olefin with aqueous hydrogen peroxide in a solvent miscible with water in the presence of a catalyst which is the titanium-containing zeolite according to claim 16.

18. Titanium-containing zeolite produced by the method according to claim 1 having a primary crystallite size of 0.2 to 2.0 μ

m.

19. A method for the epoxidation of olefins comprising reacting an olefin with aqueous hydrogen peroxide in a solvent miscible with water in the presence of a catalyst which is the titanium-containing zeolite according to claim 18.