Catalytic Upgrading of Pyrolytic Oil via In-situ Hydrodeoxygenation

Lignocellulosic biomass derived from non-food crops cultivated on lands that are increasingly marginal for more favoured major crops is a potential source of sustainable renewable energy. This study explores the transformation of crude organic phase pyrolytic oil derived from Napier grass biomass into high-grade biofuel precursors via hydrodeoxygenation reaction over platinum and palladium catalysts with in-situ hydrogen generation from methanol. The reaction was conducted in a high-pressure stainless steel batch reactor at 350 degrees C, 20 wt% methanol ratio, 2 wt% catalyst loading and 60 min reaction time. The result of physicochemical analysis showed that the higher heating value of the organic liquid products collected over the catalysts increased by 35-40% relative to the raw sample. Gas chromatography-mass spectrometry results revealed significant reductions in the oxygenated compounds such as methoxyaromatics, methoxyphenols, acids, aldehydes. The degree of deoxygenation and overall extent of upgrading observed was 50-54% and 56-60%, respectively. The gas products collected were mainly carbon monoxide, carbon dioxide, hydrogen and methane. Hydrodeoxygenation, hydrogenolysis, hydrogenation, dehydration, demethylation, hydrocracking, decarbonylation and decarboxylation were the main upgrading reactions, and a multiple reaction network was proposed.