Bifunctional NiO/Al₂O₃–Catalyzed Conversion of Hemicellulose Extracted from Maize Cobs to Liquid Hydrocarbons

The growing imperative for sustainable energy sources has spurred significant interest in the catalytic conversion of biomass, such as agricultural waste, into biofuels. Lignocellulosic biomass is a promising raw material for the production of energy and bio-based chemicals. This study investigates the catalytic conversion of hemicellulose derived from maize cobs into liquid hydrocarbons using NiO/Al2O3 as a bifunctional catalyst in an aqueous phase. The process comprises the initial generation of furfural via a one-step acid-catalyzed hydrolysis-dehydration sequence, followed by its transformation into liquid hydrocarbons via aldol condensation and hydrodeoxygenation. The empirical results demonstrate a conversion efficiency of 61.08% with the NiO/Al2O3 catalyst under optimized reaction conditions (220°C, 30 bar, 1 h), corresponding to a hydrocarbon selectivity of 61.08%. Gas chromatography/mass spectrometry (GC/MS) analysis of the liquid product identified the presence of alkanes within the C7-C15 range, with heptane (28.06%) and decane (17.65%) constituting the principal products. This finding substantiates the viability of employing hemicellulose sourced from maize cobs as a feedstock for producing liquid hydrocarbons through hydrodeoxygenation catalyzed by NiO/Al2O3.