Ex situ thermo-catalytic upgrading of biomass pyrolysis vapors using a traveling wave microwave reactor

•Ex-situ microwave reactor was used to heat catalyst bed for pyrolysis upgrading.•Results were compared with conventional catalytic reactor.•Microwave heating yielded higher aromatic compounds.•Catalyst deactivation due to coking was lower in microwave reactor.•30% decrease in energy input for microwave reactor.

Microwave heating offers a number of advantages over conventional heating methods, such as, rapid and volumetric heating, precise temperature control, energy efficiency and lower temperature gradient. In this article we demonstrate the use of 2450 MHz microwave traveling wave reactor to heat the catalyst bed for thermo-catalytic upgrading of pyrolysis vapors. HZSM-5 catalyst was tested at three different temperatures (290°, 330° and 370 °C) at a catalyst to biomass ratio of 2. Results were compared with conventional heating and induction heating method of catalyst bed. The yields of aromatic compounds and coke deposition were dependent on temperature and method of heating. Microwave heating yielded higher aromatic compounds and lower coke deposition. Microwave heating was also energy efficient compared to conventional reactors. The rate of catalyst deterioration was lower for catalyst heated in microwave system.

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