PROCESS FOR PRODUCING GASOLINE

摘要

A process for producing gasoline which comprises cracking of a heavy petroleum feedstock in the presence of an aluminosilicate zeolite-containing catalyst maintained in a condition of an ascending flow at a temperature ranging from 480 to 520.degree.C and a mass velocity of said feedstock of from 6 to 40 hr-1 in the direction of said ascending flow with the formation of a reaction mixture containing gasoline, a fraction with a specific gravity of from 0.75 to 0.85 and a fraction with a specific gravity of from 0.85 to 0.95; the resulting reaction mixture is isolated from the catalyst and subjected to separation; said separated fractions are employed as recycle. Fraction with a specific gravity of from 0.75 to 0.85 is subjected to cracking in the presence of said catalyst which is in a condition of an ascending flow at a temperature of from 460 to 520.degree.C and a mass velocity of said fraction of from 6 to 40 hr-1 in the direction of said ascending flow. As a result of said cracking a reaction mixture is formed containing gasoline. The reaction mixture is separated from the catalyst and gasoline is recovered therefrom; fraction with a specific gravity of from 0.85 to 0.95 is subjected to cracking in the presence of said catalyst which is in a condition of an ascending flow at a temperature of from 460 to 520.degree.C and at a mass velocity of this fraction selected within the range of from 5 to 8 hr-1 with the formation of a reaction mixture containing gasoline and a fraction with a specific gravity of 0.85 to 0.95; said latter reaction mixture is combined with the reaction mixture obtained from said cracking of a heavy petroleum feedstock and delivered, after separation from the catalyst, to the recovery of gasoline.