METHOD OF PREPARING ALKYLGASOLINE Russian patent published in 2000 - IPC

FIELD: petroleum processing and petrochemical industries. SUBSTANCE: isobutane is alkylated with olefins in the presence of sulfuric acid. Mixture of alkylgasoline and unreacted isobutane is fed to the top of deisobutanization column, and stable C₄ isomerizate is fed to bottom of said column in amount of 10-25 vol % of amount of reaction mixture. Stable isomerizate containing, vol %: isobutane, 25-55; n-butane, 45-75 at pressure of 7-8 MPa and temperature at top, 50-55 C and 85-90 C at bottom, and there occurs separation of isobutane recycled into alkylation reactor. Fraction containing alkylgasoline and n-butane is withdrawn from deisobutanization column bottom and this mixture is fed into debutanization column to separate n-butane fraction from alkylgasoline which is together with n-butane fraction is heated in furnace to temperature of 200-430 C and is isomerized in the presence of catalyst comprising 0.40-0.55 wt % of platinum, 3-7 wt % of halogen on aluminium oxide carried at pressure of 2.0-3.5 MPa, volumetric stock rate of 1-2 h^-1. After separation of hydrogen-containing gas from unstable C₄ isomerizate, the latter is directed to stabilization column in which becomes stable and is recycled to deicobutanization column and then into alkylation reactor. EFFECT: increased yield of alkyl gasoline. 3 ex, 1 tbl