Atmospheric Hydrodeoxygenation of Biomass Fast Pyrolysis Vapor by MoO₃

Abstract

MoO 3 has been tested as a catalyst in hydrodeoxygenation (HDO) of both model compounds (acetone and guaiacol) and real biomass pyrolysis vapors under atmospheric pressure. The pyrolysis vapor was obtained by fast pyrolysis of wood or lignin in a continuous fast pyrolysis reactor at a fixed temperature of 500 °C, and it subsequently passed through a downstream, close coupled, fixed bed reactor containing the MoO 3 catalyst. The influences of the catalyst temperature and the concentration of H 2 on the HDO of the pyrolysis vapors were investigated. The level of HDO of the biomass pyrolysis vapors was not significant at temperatures below 400 °C. At 450 °C catalyst temperature and 93 vol % H 2 concentration, the wood pyrolysis vapor was more active toward cracking forming gas species instead of performing the desired HDO forming hydrocarbons. The lignin pyrolysis vapor was more resistant to cracking and yielded 16.2 wt % daf organic liquid, while achieving 52% degree of deoxygenation at 450 °C catalyst temperature under 89 vol % H 2 concentration. The corresponding energy recovery in the liquid phase was 23.5%. The spent catalyst showed two deactivation routes, coke formation and reduction of MoO 3 to MoO 2 , which is inactive in HDO. The catalyst experienced severe reduction at temperatures higher than 400 °C. The yields of coke relative to the fed biomass were in the range of 3−4 wt % daf for lignin and 5−6 wt % daf for wood. Compared to untreated bio-oil the upgraded lignin organic liquid showed improved compatibility with hydrocarbons and was miscible with a toluene/heptane mixture.

The Development of Mesoporous Ni‐Based Catalysts and Evaluation of Their Catalytic and Photocatalytic Applications

“…The catalytic conversion of biomass to biofuels through different technologies is currently being investigated globally. The thermochemical route is a significant pathway that converts biomass into liquid fuels . Bio‐oils are produced through the pyrolysis route of biomass at a temperature of 550 °C.…”

“…The microporous catalysts such as zeolites (HZSM‐5) and mesoporous catalysts such as Al‐MCM‐48, Al‐MCM‐41, Al‐SBA‐15, etc. ) have been used in the catalytic fast pyrolysis reaction.…”

“…While they are originated from the living sources and biodegradable waste, and life is cyclical, even processed byproducts need not run out. So long as there is something living on earth, it is possible to process living things components and waste products into renewable energy …”

“…The thermochemical route is a significant pathway that converts biomass into liquid fuels. [50][51][52][53][54][55] Bio-oils are produced through the pyrolysis route of biomass at a temperature of 550°C. The yield of bio-oils is almost 45% through the pyrolysis along with gases and char.…”

“…So long as there is something living on earth, it is possible to process living things components and waste products into renewable energy. [50][51][52][53] Different Products: Biomass is a versatile source of energy and chemicals. Different high-value products and chemicals can be synthesized using different lignocellulosic biomass via various catalytic and thermal processes.…”