Co-aromatization of methane and methanol over MoxZn/HZSM-5 to increase aromatic hydrocarbon yield: experimental and kinetic studies

Abstract

Co-aromatization of methane and methanol over MoxZn/HZSM-5 was conducted to improve hydrocarbon yield and methane conversion. Natural gas, coalbed methane, and coke oven gas are rich in methane. The utilization of methane-rich gas is particularly important as energy demand continues to increase and environmental requirements continue to rise. The efficient conversion to light aromatics is obtained using a co-feed of methane and methanol under relatively mild conditions and catalyzed by MoxZn/HZSM-5. In general, Mo species promote the C-H bond breaking of methane to produce intermediates. Mo is transformed into Mo2C in the co-aromatization reaction as observed by FT-IR and XPS, which leads to the higher activity and aromatic selectivity of the catalyst and can also avoid carbon deposition of the catalyst. Furthermore, kinetic analysis results indicate that olefins play an important role during the co-aromatization of methane and methanol. Olefins are the key reaction intermediates to form aromatics and olefins initially formed in the transformation reaction of methanol perhaps promote the conversion of methane.