Sustainable Production Of Liquid Biofuels And Value-Added Platform Chemicals By Hydrodeoxygenation Of Lignocellulosic Bio-Oil Over A Carbon-Neutral Mo2c/Cnf Catalyst

For the first time, this work addresses the hydrodeoxygenation (HDO) of lignocellulosic bio-oil over a carbon-neutral Mo2C/CNF catalyst for the production of liquid biofuels and value-added chemicals, thoroughly examining the effect of the temperature, initial H-2 pressure, reaction time and catalyst/bio-oil ratio. These variables had a significant influence on the process, allowing the transformation of the original bio-oil into different fractions in varying yields, including an upgraded bio-oil (17-72%), a solid product (4-44%), an aqueous phase (5-39%) and a gaseous stream (1-15%). The upgraded bio-oil comprised a mix of phenols (56-78%), cyclic ketones (7-30%), carboxylic acids (2-8%), esters (0-9%) and aromatic compounds (0-20%). The relative amounts of C, H and O of this product shifted by 34-78 wt%, 3-8 wt% and 13-62 wt%, while its HHV ranged between 9 and 35 MJ/kg. Process optimisation revealed that using a temperature of 350 degrees C, an initial H-2 pressure of 40 bar and 0.19 g cat/g bio-oil for 1 h, it was possible to convert 65% of the organic content of the bio-oil into a liquid bio-fuel with a HHV of 30 MJ/kg (twice the value of the original feedstock), which represents a deoxygenation degree of 70% and an energy efficiency of 62%. Besides, all the bio-oil organic content can be converted into a liquid product with a high proportion of phenols (79%) at 250 degrees C, applying an initial H-2 pressure of 20 bar and 0.14 g cat/g bio-oil for around 0.5 h. This liquid can be used as a sustainable phenolic-rich antioxidant additive as well as a bio-based source of aromatic compounds. Therefore, these results are a step forward in the biomass conversion over carbon-neutral catalysts.