METHOD FOR PRODUCING FUEL OILS POSSESSING SUPERIOR ECOLOGIC PROPERTIES Russian patent published in 1997 - IPC

FIELD: petroleum processing industry environmental control. SUBSTANCE: crude petroleum is processed in presence of alumina-containing catalysts preactivated by elemental sulphur. Inventive novelty of proposed method resides in fact that alumina-containing catalyst are used as complex catalytic system containing at least 50% aluminium-cobalt-molybdenum catalyst including 12-18 wt.-% molybdenum oxide and 3-8 wt.-% cobalt oxide and prepared by mixing cobalt molybdate suspension with aluminium hydroxide in hydrogen peroxide solution. Aluminium hydroxide is subjected to treatment with nitric acid in two steps, namely: first portion of aluminium hydroxide is treated with concentrated nitric acid for 0.5-2.0 h at 20-80 C, aluminium hydroxide-to-nitric acid molar ratio being (1:0.64)-(1:1.92). Next, product resulting from first step is mixed with remaining portion of aluminium hydroxide at 20-80 C, product-to-aluminium hydroxide (calculated on basis of alumina content) molar ratio being (1.5-3.0):100. Product resulting from second step of treatment is next subjected to shaping, drying and calcination. Second component of said complex catalytic system is aluminium-nickel-molybdenum catalyst. EFFECT: proposed fuel oils meet most severe requirements imposed by modern environment-protecting laws. 3 tbl