Patent ID: 6074980
Filing Date: 2000-06-13
Classification: B01J,C08F

Abstract:
A process for the manufacture of a support for catalysts containing silica, aluminum phosphate, and optionally alumina according to which, in a first stage, an alcohol, water, a silicon alkoxide and an acid are mixed in amounts such that the water/silicon molar ratio is from 2 to 50, the first stage being carried out at acid pH and comprising, the addition of water, acid, silicon alkoxide and alcohol, the temperature, during the addition, being less than or equal to 30.degree. C. to form a hydrolysis medium, and maturing the hydrolysis medium thus obtained at a temperature equal to at least 20.degree. C. and lower than the boiling temperature of the medium, so as to substitute at least part of the alkoxy groups of the silicon alkoxide by hydroxyl groups, without producing precipitation or gelling of silica, in a second stage, adding an acidic solution of an aluminum compound and a solution of a source of phosphate ions to provide sufficient phosphate ions to yield a molar ratio of between 0 and about 1 with respect to aluminum content of the final support, and, in a third stage, adding a gelling agent to the hydrolysis medium thus obtained to form a precursor gel, washing the gel with water and then by means of an organic liquid, recovering a suspension of the gel in the organic liquid, drying the suspension by atomization until a powder is recovered, and calcining the powder.