Process for preparing ethylene oxide

• US 5,380,885 A
• Filed: 06/09/1994
• Issued: 01/10/1995
• Est. Priority Date: 09/13/1993
• Status: Expired due to Fees

• Current Assignee: Shell Oil Company (Shell Plc)
• Original Assignee: Shell Oil Company (Shell Plc)
• Inventors: Kemp, Richard A.
• Primary Examiner(s): EVANS, JOSEPH
• Application Number:
  US08/259,023
• Time in Patent Office: 215 Days
• Field of Search: 549/536
• US Class Current: 549/536
• CPC Class Codes: B01J 23/688 with manganese, technetium or rhenium
• CPC Class Codes: B01J 23/8986 with manganese, technetium or rhenium
• CPC Class Codes: C07D 301/10 with catalysts containing silver or gold
• CPC Class Codes: Y02P 20/52 using catalysts, e.g. selective catalysts

Abstract

This invention relates to a process for the preparation of an ethylene oxide catalyst having improved selectivity stability which catalyst comprises depositing silver, a promoting amount of alkali metal, a promoting amount of rhenium and, optionally, a promoting amount of rhenium co-promoter selected from sulfur, molybdenum, tungsten, chromium and mixtures thereof, on a porous refractory support, at least partially drying the support, and thereafter depositing a promoting amount of nickel on the support.

Claims

1. In a process for the production of ethylene oxide wherein ethylene is contacted in the vapor phase with an oxygen-containing gas at ethylene oxide forming conditions at a temperature in the range of from about 180°

C. to about 330°

C. in the presence of a silver metal-containing catalyst, the improvement which comprises post-impregnating a catalyst comprising a catalytically effective amount of silver, a promoting amount of alkali metal and a promoting amount of rhenium supported on a suitable support having a surface area in the range of from about 0.05 m² /g to about 10 m² /g, with a promoting amount of nickel.

2. In a process for the production of ethylene oxide wherein ethylene is contacted in the vapor phase with an oxygen-containing gas at ethylene oxide forming conditions at a temperature in the range of from about 180°

C. to about 330°

C. in the presence of a silver metal-containing catalyst, the improvement which comprises post-impregnating from about 10 parts per million to about 1000 parts per million of a nickel promoter, expressed as the element, on a catalyst comprising silver, an alkali metal promoter, and rhenium promoter supported on a porous refractory support having a surface area in the range of from about 0.05 m² /g to about 10 m² /g, wherein said nickel promoter is applied to the support as a solubilized nickel compound.

3. In a process for the production of ethylene oxide wherein ethylene is contacted in the vapor phase with an oxygen-containing gas at ethylene oxide forming conditions at a temperature in the range of from about 180°

C. to about 330°

C. in the presence of a silver metal-containing catalyst, the improvement which comprises post-impregnating from about 10 parts per million to about 1000 parts per million by weight of the total catalyst of nickel compound(s), expressed as the element, on a catalyst comprising from about 1 percent by weight to about 40 percent by weight of the total catalyst of the silver compound(s), measured as the metal, from about 10 parts per million to about 3000 parts per million by weight of alkali metal compound(s), expressed as the metal, per million parts by weight of the total catalyst, and from about 0.1 micromoles to about 10 micromoles per gram of total catalyst of rhenium compound(s), expressed as the metal, to provide the catalyst with a catalytically effective amount of silver, a promoting amount of alkali metal, a promoting amount of rhenium and a promoting amount of nickel.

4. In a process for the production of ethylene oxide wherein ethylene is contacted in the vapor phase with an oxygen-containing gas at ethylene oxide forming conditions at a temperature in the range of from about 1800°

C. to about 330°

C. in the presence of a silver metal-containing catalyst, the improvement which comprises post-impregnating a catalyst comprising a catalytically effective amount of silver, a promoting amount of alkali metal, a promoting amount of rhenium and a rhenium co-promoter selected from sulfur, molybdenum, tungsten, chromium and mixtures thereof supported on a suitable support having a surface area in the range of from about 0.05 m² /g to about 10 m² /g, with a nickel promoter.

5. In a process for the production of ethylene oxide wherein ethylene is contacted in the vapor phase with an oxygen-containing gas at ethylene oxide forming conditions at a temperature in the range of from about 180°

C. to about 330°

C. in the presence of a silver metal-containing catalyst, the improvement which comprises post-impregnating from about;

10 parts per million to about 1000 parts per million of a nickel promoter, expressed as the element, on a catalyst comprising silver, an alkali metal promoter, a rhenium promoter and a rhenium co-promoter selected from sulfur, molybdenum, tungsten, chromium and mixtures thereof supported on a porous refractory support having a surface area in the range of from about 0.05 m² /g to about 10 m² /g, wherein said nickel promoter is applied to the support as a solubilized nickel compound.

6. In a process for the production of ethylene oxide wherein ethylene is contacted in the vapor phase with an oxygen-containing gas at ethylene oxide forming conditions at a temperature in the range of from about 1380°

C. to about 330°

C. in the presence of a silver metal-containing catalyst, the improvement which comprises post-impregnating from about 10 parts per million to about 1000 parts per million by weight of the total catalyst of nickel compound(s), expressed as the element, on a catalyst comprising from about 1 percent by weight to about 40 percent by weight of the total catalyst of the silver compound(s), expressed as the metal, from about 10 parts per million to about 3000 parts per million by weight of alkali metal compound(s), expressed as the metal, per million parts by weight of the total catalyst, from about 0.1 micromoles to about 10 micromoles per gram of total catalyst of rhenium compound(s), expressed as the metal, and from about 0.1 micromoles to about 10 micromoles per gram of total catalyst of rhenium co-promoter compound(s), expressed as the element, to provide the catalyst with a catalytically effective amount of silver, a promoting amount of alkali metal, a promoting amount of rhenium, a promoting amount of rhenium co-promoter and a promoting amount of nickel.