METHOD OF PREPARING HIGH-OCTANE GASOLINE ADDITIVES Russian patent published in 2001 - IPC

FIELD: gasoline production. SUBSTANCE: isobutene-containing hydrocarbon mixture(s) and ethanol are brought into contact with acidic ionite catalyst(s) in two or several straight-flow reaction zones and unreacted C4-hydrocarbons are separated in rectification zone. At last one of reaction zones is followed by rectification zone and at least one of reaction zones is connected with rectification zone so that the latter receives side stream tapped off at point above that where reaction mixture from precedent reaction zone is fed and, possibly, additional amount of ethanol. Reaction mixture from that rectification zone is returned into rectification zone below the side stream withdrawal point. Total amount of ethanol is superior to summary molar amount of isobutene in initial hydrocarbon mixture and ethanol in distilled off stream of unreacted hydrocarbons. High-octane mixture containing 50 to 97 wt % of ethyl tert-butyl ether and 3 to 50 wt % of ethanol. EFFECT: decreased formation of by-products resulting in reduced activity of catalyst. 3 cl, 2 dwg, 6 ex