Patent ID: 6642172
Filing Date: 2003-11-04
Classification: B01J,C07C

Abstract:
An extruded catalyst consisting of:a catalytically active portion of silica/alumina gel having a silica/alumina molar ratio ranging from 50:1 to 500:1 and an inert binding agent, which is prepared by: (a) preparing an aqueous solution of a tetraalkylammonium hydroxide (TAAâ€”OH), a soluble aluminum compound capable of yielding Al2O3 by hydrolysis and a silicon compound capable of yielding SiO2 by hydrolysis, in the following molar ratios: SiO2:Al2O3=from 50:1 to 500:1 TAAâ€”OH:SiO2=from 0.05:1 to 0.2:1 H2O:SiO2=from 5:1 to 40:1; (b) heating the resulting solution (a) in order to effect hydrolysis and gelation of the components of solution (a) thereby obtaining mixture (A) having a viscosity within the range of from 0.01 to 100 Pa sec; (c) adding to said mixture (A), firstly a binding agent selected from the group consisting of a boehmite and a pseudo-boehmite, in a ratio, by weight, to said mixture (A) within the range of from 0.05 to 0.5, followed by a plasticizer, and then adding an organic acid in an amount within the range of from 0.5 to 8 g per 100 g of binding agent; (d) mixing the combined material of step (c) and heating the mixture to a temperature within the range of from 40 to 90Â° C. until a homogeneous paste is obtained; (e) extruding said paste; (f) drying the extrudate; and (g) calcining the dried extrudate under an oxidizing atmosphere, wherein the axial breaking strength of the catalyst ranges from 99 kg/cm2 to 280 kg/cm2.