FCC Gasoline: Gas Oil Cracked over Fluidised Silica-Alumina at 975 °F, 71.5 % Conversion (Gulf, US 3,071,535)

In a fluid catalytic cracker, gas oil vapour streams up through a bed of fine silica-alumina powder kept floating by the gas, and breaks into gasoline and lighter products. Gulf ran theirs hotter than usual, at 975 °F, to make more butylenes for alkylation. Result (Gulf's example, barrels per day): from 44,840 of gas oil, 15,052 of gasoline boiling to 400 °F plus 4,393 of pentane fraction, with 7,547 of C4-C5, 4,230 of C3, 10,555 of light gas oil and fuel gas. Conversion 71.5 %. Source: Condrasky & Glazier, US 3,071,535 (Gulf, filed 1959). The heavy gas oil and coker gas oil come from Gulf's own crude unit and coker. Not given: catalyst regeneration, space velocity, how the gasoline is sweetened. Hot oil vapour: fire risk. Picture drawn by Youblob.