Hβ/HZSM-5 Composite Carrier Supported Catalysts for Olefins Reduction of FCC Gasoline Via Hydroisomerization and Aromatization

In order to develop a novel catalyst system that has excellent olefin reduction ability for FCC gasoline without loss in research octane number (RON), different catalysts supported on single- and binary-zeolite carriers consisting of Hβ or/and HZSM-5 were prepared and their catalytic performances for FCC gasoline upgrading were assessed in the present investigation. Acidity measurements by pyridine-adsorbed Fourier transformed infrared spectroscopy (FTIR) showed that hydroisomerization and aromatization activities were closely related to the density of acid sites and the ratios of medium Lewis acidity and strong Brönsted acidity to total acidity. Compared with the single HZSM-5 supported catalyst, the single Hβ supported catalyst was found to have much better olefin reduction performance, but the product RON still suffered from a loss of 1.6. Compared to the single-zeolite supported catalysts, the binary-zeolite Hβ/HZSM-5 supported catalysts with the mass ratio of Hβ to HZSM-5 at 6.6 offered much more stable activity and selectivity to arene, which played an important role in preserving gasoline RON.