The advance in catalytic pyrolysis of naphtha technology using ZSM-5 as catalyst

Light olefins, especially ethylene, have been produced mainly by hydrocarbon steam cracking in recent decades. Recent studies have shown that a considerable amount of propylene and ethylene can be produced by hydrocarbon cracking on modified ZSM-5 zeolite. This article emphasizes the current research progress that acidcatalyzed paraffin cracking leads to high yields of light olefins. Propylene and ethylene were produced by the catalytic pyrolysis of different kinds of paraffin over modified ZSM-5 zeolite and summarizes the mechanism and factors influencing the catalytic pyrolysis of paraffin, i.e., various modified elements and posttreatment methods have been employed, such as rare earth elements, alkaline earth and alkali elements, transition metals, P, steaming and alkali treatments, the influences on the properties of modified ZSM-5, and the selectivity of light olefins. In addition, the effects of different factors that contain the acid properties of zeolite, the ratio of Si/Al, and process conditions on the production of ethylene and propylene are discussed, and the effects of modified elements on the catalytic pyrolysis mechanism are summarized. We look forward to the development status of the catalytic pyrolysis process and expected future development orientation.