An experimental study of the endothermic catalytic cracking of hydrocarbon aviation fuels under extreme conditions

Abstract

Methylcyclohexane (MCH) is a suitable surrogate endothermic fuel that can operate under extreme conditions and it can be utilized to better understand the mechanisms of endothermic catalytic cracking and coke generation in jet engines. Zn-impregnated desilicated Zeolite Socony Mobil-5 (ZSM-5) zeolite catalysts have been successfully prepared and studied for aviation fuel cracking under high temperature and pressure conditions (550 degrees C; 50 bar). First, micropore ZSM-5 was desilicated by the alkali treatment method with NaOH to increase the mesopore distributions. In the second step, Zn-doped mesopore ZSM-5 zeolites were prepared by the incipient wetness impregnation method with an aqueous solution of zinc nitrate. After the endothermic pyrolysis of MCH fuel over the modified zeolite catalysts, the condensed liquid product fraction (%) was analyzed. It can be deduced that a reasonable combination of these advanced synthesis strategies can increase catalytic cracking performance. This study showed that, in the context of endothermic catalytic cracking of hydrocarbon aviation fuels at supercritical jet conditions, Zn-doped desilicated zeolites exhibited a decreased quantity of coke deposition.