Aromatization of Cracking Gasoline on ZSM-5 Zeolites

The aromatization of cracking gasoline on HZSM-5 and metal (Zn) modified HZSM-5 zeolites was investigated by using a continuous flow-reaction apparatus. The yields of the aromatics in liquid products were enhanced. A effective process of aromatization was proposed to abate the effects of sulfur and coke impurities in cracking gasoline, such as: distillation(in order to wipeout coke); hydrogenation-desulfuration;aromatization in hydrogen atmosphere;condensation of the products in order to obtain aromatics.The relationship between the solid acidic properties of the catalysts and its aromatization reactivity was also studied by using the methods of Temperature-Programmed-Desorption of ammonia. It was found that the suitable strcnth distribution and amount of acid sites on Zn-ZSM-5 may be one of the reasons for the high aromatization activity and selectivity of this catalyst.