Sulfuric Acid Alkylation of Isobutane with Olefins in a Microemulsion Medium Using a Dimethyldioctadecylammonium Salt

The formation of a Winsor III microemulsion is detected for the first time in a system of concentrated H2SO4 + C4–C6 alkanes with added quaternary ammonium salt dimethyldioctadecylammonium chloride (C18H37)2N+(CH3)2Cl– acting as a surfactant. The effect this microemulsion has on parameters of the sulfuric acid alkylation of isobutane (iB) with 1-butene (1b) and 1-pentene (1p) is studied. Adding only 0.03 wt % of surfactant relative to H2SO4 sharply alters many parameters of the process, relative to using pure H2SO4. The conversion of isobutane rises by 1.5–2 times. The yield of C8 products produced by the olefin can double, with the research octane number reaching 100 points. NMR shows that relative to unmodified acid, the number of resulting acid-soluble oils (ASOs) falls by 15–20 times after using the microemulsion in the alkylation of isobutane with 1-butene.