TH72055A - Modified alumina conductors And silver based catalysts for the production of alkylene oxide. - Google Patents

Abstract

DC60 (16/11/47) An improved conductor useful for preparing catalysts with excellent catalytic performance when used in the production of alkylene oxides, such as ethylene oxide. The conductor is prepared by a) impregnating the pre-made alpha-alumina conductor with at least one modifier selected from among the alkali metal silicates and alkaline earth metal silicates, b) drying the impregnated conductor; and c) calcining the dried conductor. Optionally, the conductor may be washed before impregnation with the catalytic material and/or common promoter material. An improved conductor useful for preparing catalysts with excellent catalytic performance when used in the production of alkylene oxides, such as ethylene oxide. The conductor is prepared by a) impregnating the pre-made alpha-alumina conductor with at least one modifier selected from among the alkali metal silicates. and alkaline earth metal silicate, b) drying of such impregnated conductors; and c) calcination of such dried conductors. The conductors may be chosen to be washed, before being impregnated with the catalytic material and/or common promoting material.

Claims (15)

1. The method for preparing modified conductors for catalysts to be used for vapor phase epoxidation of alkenes, which consists of: a) impregnating the pre-made alpha-alumina conductor with at least one modifier chosen from among the alkali metal silicates and alkaline earthmetal silicates; b) drying the impregnated conductor; and c) calcining the dried conductor. 2. The method of Claim 1, in which such modifier is selected from a group consisting of sodium silicate, lithium silicate, and potassium silicate, or a mixture of these substances. 3. Method of Claim 1, whereby the modifier is sodium silicate with a relative concentration of Na20-2.6 SiO2. 4. The method of claim 1, in which the modification is performed at a temperature not exceeding approximately 250 degrees Celsius for the first two hours, followed by the aforementioned wetting. 5. Methods for preparing modified conductors for catalysts to be used for vapor phase epoxidation of alkenes, which include: a) impregnating the pre-made alpha-alumina conductor with at least one modifier chosen from among the alkali metal silicates and alkaline earth metal silicates; b) drying the impregnated conductor; c) calcining the dried conductor; and d) depositing sulfur catalyst material on the dried conductor. 6. Method of Claim 5 in which at least one enhancing agent is deposited onto the pre-made alpha-alumina. 7. Method of Claim 6, in which such enhancing agent is selected from a group containing at least one alkali metal, alkaline earth metal, or oxyanion, other than oxygen, with atomic numbers 5 to 83, and chosen from groups 3b to 7b and 3a to 7a of the periodic table. 8. Method of claim number 6, in which the enhancing agent is the salt of a member of the redox half-reaction pair. 9. Method of claim number 6, where the enhancing agent is the rhenium component. 10. Method of claim 1 or 5, in which the aforementioned aldene is ethylene. 11. A catalytic modified conductor used for vapor phase epoxidation of alkaline prepared by a method comprising; a) impregnation of the pre-made alpha-alumina conductor with at least one modifier chosen from among the alkaline metal silicates and alkaline earthmetal silicates; b) drying of the impregnated conductor; and c) calcination of the dried conductor. 12. A novel catalyst for vapor-phase alkyne epoxidation prepared by a method comprising: a) impregnation of a pre-made alpha-alumina conductor with at least one modifier selected from the group of alkali metal silicates and alkaline earthmetal silicates; b) drying of the impregnated conductor; c) calcination of the dried conductor; and d) deposition of sulfur catalyst on the dried conductor. 13. Method of Claim 1 in which a prefabricated alpha-alumina conductor comprises flake/fluoride alumina containing at least 95% by weight of alpha-alumina, a characteristic interlocking flake morphology, and a surface area of at least approximately 0.5 sq.m./g, a pore volume of at least approximately 0.5 cc./g, and an average pore diameter between approximately 1 and 25 microns. 14. Method of Claim 13, where the modifier is sodium silicate with a relative quantity, Na20-2.6 SiO2. 15. The method of claim 1 or 13, in which the modified conductor is subsequently cleaned after calcination.