Load catalyst used for preparing vinyl acetate monomer

Abstract

The invention provides a load catalyst used for preparing vinyl acetate monomer. Based on thermolysis-prepared mixed oxide with the following physic-chemical parameters, including that outer diameter is 0.8-25mm, BET surface area is 5-400m2 / g, pore volume is 0.2-1.8ml / g, fracture strength is 5-350N, composition is random combination of at least two of SiO2, Al2O3, TiO2 and ZrO2 and weight percent of other components is less than 1wt% besides SiO2 / Al2O3 mixed oxide with the weight percent of SiO2 more than 75wt% in the mixed oxide and bulk density is 250-1500g / L, molding bodies are prepared by the steps: the required thermolysis-prepared mixed oxide and one or multiple compounds selecting from methylcellulose, methyl hydroxyethyl cellulose, wax, polyvinyl alcohol, magnesium stearate and / or aluminium stearate are added with water, homogenized and then dried at the temperature of 70-150 DEG C, smashing at random is carried out to obtain powder, the powder is compacted at random to obtain molding bodies, and heat treatment is carried out at the temperature of 400-1200 DEG C for 0.5-10 hours. The moldings are doped with appropriate active components to prepare vinyl acetate monomer by utilizing gas phase process.

Description

technical field [0001] The present invention relates to a supported catalyst based on pyrolytically produced mixed oxides, which catalyst is especially suitable for the production of vinyl acetate monomer (VAM). Background technique [0002] The pyrolytically produced oxides are distinguished by their very fineness and correspondingly increased specific surface area, their very high purity, their spherical particle shape and their absence of pores. Owing to these characteristics, there has been increasing interest in using pyrolytically prepared oxides as catalyst supports (D. Koth, H. Ferch, Chem. Ing. Techn. 52, 628 (1980)). In some cases, fumed oxides are also used as catalysts. [0003] Since the pyrogenically produced oxides are particularly finely divided, shaping them into catalyst supports or catalysts faces some difficulties. [0004] DE-B 21 00 778 discloses the use of pyrogenically produced silica spheres as catalyst supports in the production of vinyl acetate m...

AI Technical Summary

Problems solved by technology

[0007] A disadvantage of these prior art processes is that they result in catalysts which lead to an unfavorable relationship between selectivity and activity in the production of vinyl acetate monomer