Catalytic hydropyrolysis of biomass over NiMo bimetallic carbon-based catalysts

Catalytic hydropyrolysis (CHP) is an emerging and promising technology to convert lignocellulosic biomass resources into alternative fuels and valuable chemicals. In this work, NiMo bimetallic carbon-based catalysts were designed and applied in the thermal conversion of alkaline lignin at 450 & DEG;C, 500 & DEG;C, and 550 & DEG;C under 1 atm H2. The CHP process exhibited a higher deoxygenation extent of around 60% compared with pyrolysis (FP) and hydropyrolysis (HP) processes. The bio-oil with higher H/C ratio and lower O/C ratio corresponding to a chemical formula of CH1.167O0.245 was obtained at 500 & DEG;C over the IW catalyst prepared via incipient wetness impregnation. CO2 and CO were generated via the decarboxylation and decarbonylation reactions, respectively. As for the CHP of real biomass, the deoxygenation extent reached about 55% over different modified catalysts. The ball milling-melting catalyst showed a considerable liquid product yield of 35.0 wt% and the best bio-oil quality with the chemical formula of CH1.456O0.339. The remarkable hydrodeoxygenation activity of carbonderived catalysts was attributed to the synergistic effect of metallic Ni0 and intermediate oxidation state of Mo2 & PLUSMN;/Mo & delta;& PLUSMN;. The active hydrogen was adsorbed on the nickel sites, and the molybdenum species were responsible for eliminating the oxygen in aromatic oxygenates.

Automated summary

Catalytic hydropyrolysis is a novel technology for converting lignocellulosic biomass into alternative fuels and chemicals. This study designed and applied NiMo bimetallic carbon-based catalysts in the conversion of alkaline lignin. The process showed higher deoxygenation extent compared to pyrolysis and hydropyrolysis processes. The carbon-derived catalysts exhibited remarkable hydrodeoxygenation activity due to the synergistic effect of Ni0 and Mo2+/Moδ+.