a Kochi Pref. Ind. Tech. Center, Nunosida 3992 Kochi 781-5101 Japan
b CCIC, 13-2 Kitaminato Wakamatsu Kitakyusyu 808 Japan
c NIMC AIST MITI, 1-1 Higashi Tsukuba Ibaraki 305 Japan
Abstract:
Background and strategy of catalyst development for upgrading aromatic hydrocarbons are intensively discussed. Originally prepared catalysts (hydrogenation and hydrocracking catalysts) were used for accelerated aging tests. Though each catalyst showed superior catalytic performance as compared to commercially available catalysts, a severe deactivation was observed on the hydrocracking (HC) catalysts. A new type of HC catalyst was designed and prepared, based on the understanding of catalyst deactivation. High silica NaY zeolites were synthesized using crown-ether. USY zeolites were then prepared by ion exchange, steaming and calcining. Surface properties and catalytic functions of well-crystallized USY zeolites were investigated to develop practical HC catalysts. The Ni–W catalyst prepared using the newly prepared USY zeolite showed a considerable improvement in the HC activity.