Study on Generation and Conversion of Methyl Ions in Cracking Reactions
The catalytic cracking behavior of pentene on two MFI zeolites with different densities of active sites was investigated on a fixed bed micro-reactor.It was found that there were significant differences in the composition of gas-phase products of the both,especially hydrogen and methane;further comparison was made by introducing the gas composition in thermal cracking reaction.The results reveal that under the environment of strong hydride transfer reaction,the methyl ions are prone to dimerization or polymerization with olefins,and hydrogen ions also tend to migrate.In the thermal cracking reaction system almost without the occurrence of negative hydrogen ions transfer,methyl radicals mainly combine with hydrogen radicals or extract hydrogen to produce methane.The generation of methane in thermal cracking and catalytic cracking reaction processes is essentially similar,both originating from the combination of precursor methyl ions and hydrogen ions.This work provides a theoretical basis for regulating the reaction path of methyl ions,thus suppressing methane generation.
NETL
NSTL
万方数据
