Wenzhang Wu, Wenyao Guo, Wen-de Xiao
Oct 15, 2011
Citations
2
Influential Citations
96
Citations
Quality indicators
Journal
Chemical Engineering Science
Abstract
Abstract The reaction pathway for propene formation in methanol to propene (MTP) process over a high silica H-ZSM-5 catalyst has been investigated in a fixed bed reactor by comparing the experimental results from three kinds of feeding: alkene only, methanol only and mixed alkene and methanol. The results show that alkene methylation with methanol is dominant for the case of methanol and individual C 3 –C 6 alkenes co-feeding, C 2 = is almost un-reactive. C 7 = cracks to propene and butene immediately whether co-fed with methanol or not, and C 6 = cracks to propene readily when reacted alone. Oligomerization occurs but is suppressed by the co-fed methanol for light alkenes of C 2 –C 5 . Methylation-cracking has been verified as the main reaction mechanism of a typical MTP process in which recycling of C 2 = and C 4 = –C 6 = to the reactor inlet is required. Based on the relative reactivities of alkenes towards methylation and inter-conversion, a reaction scheme has been presented including a cycle composed of a consecutive methylation from C 4 = through C 5 = to C 6 = and further to C 7 = , the β-scission of hexene and heptene for propene, and the α-scission of hexene for ethene as well.