Conversion of isobutane-butenes mixtures on H-USY and SO2−4/ZrO2 catalysts under supercritical conditions: Isobutane alkylation and butenes oligomerization

The conversion of isobutane-butenes mixtures on the H-form of ultrastable zeolite Y and sulfated zirconia under supercritical conditions at 150–160°C and 80 atm was studied. The isobutane/C 4 -olefins molar ratios (I/O) were 1.5, 14, and 28. In isobutane alkylation (I/O = 14 and 28), sulfated zirconia was more stable: at 150°C and 80 atm, the olefin conversion above 90% was retained for 5 h. Under the same conditions, the deactivation of the zeolite catalyst started after 1–2.5 h (depending on the initial I/O ratio). Selectivity for the formation of C 8 hydrocarbons was 30–40%. An increase in the butene content of the initial mixture led to the domination of the dimerization of butenes over the alkylation of isobutane.