HIGH-OCTANE GASOLINE COMPONENT PREPARATION METHOD Russian patent published in 2004 - IPC

FIELD: petrochemical processes. SUBSTANCE: isobutane fraction is alkylated with butane-butylene fraction in presence of concentrated sulfuric acid, which is continuously added into alkylation reactor. Olefin feedstock, fresh and recycling sulfuric acid as well as fresh and recycling isobutane flow in parallel streams into each reaction section of reactor, while reaction mixture overflows from one level of reactor into another, spent sulfuric acid is simultaneously removed. Reaction mixture consisting of sulfuric acid, isobutane, and alkylation product is settled, subjected to acid and alkali treatment and passed into deisobutanization column to remove isobutane, which is recycled into alkylation reactor. Alkylation is carried out consecutively in two reaction apparatuses having autonomous circuits for circulation of sulfuric acid, which is separated from reaction products after their withdrawal from each reaction apparatus. In the first reaction apparatus, butylene-containing feedstock is added to isobutane/sulfuric acid emulsion, while propylene-containing fraction is additionally introduced into gas product mixture removed from the first reaction apparatus and/or into the second reaction apparatus at propylene-to-isobutane volume ratio between 1:4 and 1:6. Alkylation of isobutane with propylene-containing fraction is conducted at flow rate of the latter 0.7-1.5 m³/h (calculated for propylene) per 1 m³ sulfuric acid in reactor space. EFFECT: increased yield of high-quality alkylated gasoline. 5 ex