Study Of Methyl Chloride To Olefins On F Modified ZSM-35 Molecular Sieve Catalyst

In recent years,the demand for propylene is increasing,while the traditional way of producing propylene is based on oil as raw material,obtained by steam cracking and fluidized catalytic cracking,but oil is non-renewableresources.so in order to solve the energy crisis,to meet the social production and life Broad demand,the development of more cost-effective new way of production of propylene is the focus of the study,one of the more popular research is based on methane as the intermediate product of methane propylene reaction process.The two catalysts in the process are H-ZSM-5 and H-SAPO-34,but H-SAPO-34 is inactivated due to the low selectivity of H-ZSM-5 to lower olefins and the inactivation of H-SAPO-34 The H-ZSM-35 catalyzed the conversion of chlorinated methane with high selectivity and good propylene has good research significance.In this paper,H-ZSM-35 zeolite catalysts with Si / Al ratio of 15,25,40 were synthesized by pyrolysis as a template.The catalysts were characterized by SEM,NH3-TPD and XRD.The catalytic performance of H-ZSM-35 under different reaction conditions(partial pressure,temperature,silica-alumina ratio)was investigated.The reaction conditions were optimized.In the paper,in order to obtain more methyl chloride conversion and propylene selectivity.the catalyst was modified with high temperature calcination at different concentrations of NH4F(0.02 M,0.03 M,0.04 M,0.05 M,0.06M),The effects of F treatment on the catalytic performance of the catalyst were investigated by SEM,NH3-TPD and XRD.The results show that the modification of fluorine has great influence on the catalytic performance of molecular sieves.The reaction exhibits a best catalytic performance when the fluorine content is 0.03 M,Not only the amount of methane conversion has increased(about 10%),but also the selectivity of propylene is also significantly improved(about 20%).