Johannes W. Schwank, Chemical Engineering, University of Michigan, 2300 Hayward, 3014 H.H. Dow Building, Ann Arbor, MI 48109-2136 and Benjamin D. Harris, Chemical Engineering, Transportation Energy Center, University of Michigan, 2300 Hayward, 3014 H.H. Dow Building, Ann Arbor, MI 48109-2136.
Introduction of gallium into ZSM-5 catalysts has been shown to increase the yield of aromatic compounds formed from light olefins (C2-C4). Temperatures used for this reaction are typically above 400 °C. However, in combination with a Fischer-Tropsch Synthesis (FTS) catalyst, Ga/ZSM-5 catalysts have been shown to be active for aromatization reactions at lower temperatures. The activity of Ga/ZSM-5 catalysts synthesized by wet impregnation has not been sustained under FTS conditions (hydrogen, water and a wide range of hydrocarbons present at a time on stream of 15+ hr), though. Gallium incorporation into the MFI (ZSM-5 type) framework of zeolites has been shown to perform the aromatization reaction of propene with greater selectivity than Ga/ZSM-5 and to have gallium more uniformly distributed throughout the zeolite channels and surface. Additionally, the Ga-MFI zeolite has not been tested under FTS conditions. To better understand if an improvement may be made for the production of aromatic compounds alongside a FTS catalyst, the Ga-MFI zeolite was tested using propylene under FTS conditions.