The production of phthalic anhydride by the oxidation of the aromatic hydrocarbons of a catalytic gas-oil

Abstract 1. 1. The vapour-phase catalytic oxidation of a narrow fraction—230–245° —of catalytic gas-oil from the Novo-Ufa petroleum refinery over an industrial complex vanadium-potassium-sulphate catalyst for the production of phthalic anhydride has been studied. 2. 2. It has been found that when the 230–245° fraction of catalytic gas-oil is oxidized (reactor temperature 360–370°, space velocity 2500 hr −1 , air : raw material ratio 206 g/g . hr), the main components of the fraction ignite, and under these conditions, the yields of phthalic and maleic anhydrides do not exceed 27·9 and 3·7% by weight, respectively. 3. 3. The oxidation of a concentrate of the furfural extract of the catalytic gas-oil on the same catalyst has been studied. 4. 4. The optimum conditions for the oxidation have been found to be: reactor temperature 390°, space velocity 2500 hr −1 , air : raw material ratio 250 g /g . hr. Under these conditions, the yields of phthalic and maleic anhydrides amount to 38·3 and 5·1% by weight, respectively.