Optimized method for the production of catalyst supports based on silica gel and chromium catalysts supported on silica gel

A method for the production of a catalyst support comprising the following steps:

• a) production of a silicic acid hydrogel having a solids content of from 10 to 25% by weight (calculated as SiO2) whose particles are substantially spherical, by
• a1) introducing a sodium water-glass or potassium water-glass solution into a swirling stream of a mineral acid, both longitudinally and tangentially to the stream to give the silicic acid hydrosol,
• a2) spraying of the resultant hydrosol in drop form into a gaseous medium,
• a3) allowing the hydrosol to solidify in the gaseous medium to give substantially spherical hydrogel particles,
• a4) washing of the resultant hydrogel particles in order to free the hydrogel from salts,
• b) extraction of the hydrogel particles with an alcohol until at least 60% of the water present in the hydrogel has been removed,
• c) drying of the resultant hydrogel until the residual alcohol content than 10% by weight (xerogel formation) at temperatures of 160° C. at atmospheric pressure using an inert entraining gas,
• d) setting of the desired particle size of the resultant xerogel, and wherein at least 90 to 99% by weight of said particles have a particle size 8 mm before the extraction.