METHOD OF SYNTHESIS OF CATALYST FOR CONVERSION OF SO TO SO Russian patent published in 2002 - IPC

FIELD: chemical technology, catalysts. SUBSTANCE: invention relates to methods of synthesis of vanadium sulfuric acid catalysts. Method of synthesis of catalysts involves precipitation of hydrosilica gel as a carrier from the system comprising dissolved silicon dioxide taken in the definite concentration, mixing and/or impregnation of a carrier with active components containing vanadium, alkaline metals and sulfur oxides, molding, drying and calcinations. The precipitation of carrier is carried out in silicon dioxide concentration 120-270 g/l before precipitation and after termination of precipitation and before mixing with active components a carrier is subjected for thermic treatment for 0.5 h, not less at temperature 30 C, not below, at pH in the range from 5.2 to 11.5. The precipitation of carrier is carried out by pouring acid preferably to system containing the dissolved silica. The precipitation can be carried out for two steps and on the first step concentration of silicon dioxide is maintained up to 160 g/l and on the second step it is increased by jump-type procedure. Mixing a carrier pulp with active component solutions is carried out at temperature 20 C, not below. Time of thermic treatment of a carrier is less 48 h and it can be decreased by stirring. Thermic treatment of a carrier can be combined with filtration, washing out and repulpation. Invention provides increase of stability of catalyst activity at 420 C under conditions of transient cooling a layer in reaction medium. EFFECT: improved method of synthesis. 8 cl, 1 tbl, 8 ex