Alkylation of Isobutane by 1-Butene over H-beta Zeolite in CSTR (Part 1) Effects of Zeolite-structures and Synthesis Methods on Alkylation Performance

The effects of zeolite structures on alkylation of isobutane with 1-butene were investigated in a batch reactor and in a continuously stirred tank reactor (CSTR) using the proton-form zeolites, H-ZSM-5, H-L, H-Y, and H-*BEA (beta). H-ZSM-5 and H-L zeolite catalysts were deactivated rapidly, whereas H-Y and H-*BEA zeolites retained catalytic activity for a long time in the CSTR, implying that zeolites with three-dimensional large pore systems are useful for preventing deactivation of the catalyst during alkylation of isobutane with 1-butene. H-*BEA synthesized using a dried-gel method (DGC-H-*BEA) showed the most stable activity among the various H-*BEA zeolites. The effects of the synthesis methods and zeolite characteristics were investigated using H-*BEA zeolite. Characterization using NH3-TPD and pyridine-sorption monitored by FT-IR showed that high acid density and high Brønsted acid ratio promoted alkylation of isobutane with 1-butene over H-*BEA zeolite.