Conversion of Methanol and Glycerol into Gasoline via ZSM-5 Catalysis

Abstract

A quartz fixed-bed, microreactor was successfully constructed for both the catalytic methanol-to-gasoline (MTG) and methanol-and-glycerol-to-gasoline (MGTG) processes. The reaction products were analyzed by gas chromatography–mass spectrometry (GC–MS) and high-performance liquid chromatography (HPLC). Process variables of temperature and reaction time were studied to determine the effects on conversion rates, product yield, and ZSM-5 catalyst lifetime for both systems. Moreover, the factor of glycerol additions (10, 25, and 40% in methanol) was also investigated for the MGTG process. The MTG and MGTG generated oil phase showed a similar composition, mainly methylbenzenes, to regular gasoline, and composition changed as the reaction proceeded to favor heavier aromatics. In the MTG process, the best catalytic performance was achieved at 425 °C, at which the product yield and catalyst lifetime were 11.0 wt % and 20 h, respectively. Generally, the methanol conversion rate and the total liquid and organic-phase yield rates decreased with the reaction time at each temperature. In addition to gasoline-range aromatics, some oxygenates were also detected in the extracted aqueous phase from the MGTG process. The best MGTG catalytic performance was achieved at 500 °C with 10% glycerol in methanol, at which the product yield and catalyst lifetime were 14.9 wt % and 8 h, respectively. The higher glycerol content disfavored the production of aromatics but favored oxygenates. With an increasing reaction time at all reaction conditions, methanol and glycerol conversion rates were ≥99%.