Abstract
Alkylation of isobutane with butene is an important industrial process for producing high-octane gasoline. Current industrial alkylations use either H2SO4 or HF as a catalyst. Compared to the liquid catalyst, the use of a solid acid catalyst tremendously reduces or eliminates the potential hazard of large acid spills. In this study, a HY zeolite, sulfate-promoted titania, mixed oxide of TiO2/ZrO2, TiO2/Al2O3, and ZrO2 were synthesized. Two different sulfate-promoted zirconias, (MSG-ZrO2-S and PPT-ZrO2-S) were synthesized by the modified sol gel method and the precipitation method. The alkylation results indicated MSG-ZrO2-S had a significant larger butene conversion, C8 yield, and C8/C9 + ratio than PPT-ZrO2-S. MSG-ZrO2-S also had a larger C8/C9+ ratio than HY. MSG-TiO2-S and its related binary oxide were not active. MSG-ZrO2-S had more acid sites over the entire acidity range than PPT-ZrO2 -S. Compared to HY, MSG-ZrO2-S has a fewer number of weak and medium acid sites, as well as a greater number of strong acid sites. MSG-Ti02-S had the smallest amount of acid sites indicated by the ammonia TPD analysis. The reaction temperature significantly affected alkylation activity of HY. Butene conversion, C5+ yield, and n-butane production were dramatically increased with the increase of temperature with the decrease of C8/C9+. Isobutane to butene ratio had no significant effect on alkylation. A larger isobutane to butene ratio, however, was more favorable for the production of C8 than the production of light ends. All active catalysts used in this study showed rapid deactivation. The cause of deactivation is believed to be the deposit of polymer on the active sites. The experimental data obtained from HY-catalyzed alkylation were well fitted by the simulated results based on a simplified kinetic model. All 16 parameters used in the kinetic model were evaluated through the parameter estimation.
Liang, Chin-Huang (1993). Alkylation of isobutane with n-butene over solid catalysts. Texas A&M University. Texas A&M University. Libraries. Available electronically from
https : / /hdl .handle .net /1969 .1 /DISSERTATIONS -1482000.