Production of jet fuel-range hydrocarbon biofuel by hydroxyalkylation–alkylation of furfural with 2-methylfuran and hydrodeoxygenation of C15 fuel precursor over a Ni/γ-Al2O3 catalyst: a reaction mechanism

Abstract

This study presents manufacturing jet fuel-range (C₉–C₁₅) hydrocarbon biofuels from 2-methylfuran and furfural. The process involves a hydroxyalkylation–alkylation reaction, followed by hydrodeoxygenation of the C₁₅ fuel precursor. The hydroxyalkylation–alkylation reaction was investigated under various cation exchange resin loadings, furfural/2-methylfuran molar ratios, and reaction temperatures. The hydroxyalkylation–alkylation reaction results were further corroborated by an appropriate kinetic model. Hydrodeoxygenation proceeds via the sequential furan ring-hydrogenation and ring-opening reactions, followed by the combination of dehydroformylation, hydrodeoxygenation, and cracking reactions. The dehydroformylation reaction was the leading pathway over a Ni/γ-Al₂O₃ catalyst, forming mainly C₁₄H₃₀ alkane. The oxygenate conversion was boosted with rising hydrogen pressure, Ni metal content on γ-Al₂O₃, and reaction temperatures. Both hydrodeoxygenation and hydrogenation reactions proliferated at elevated hydrogen pressure with the enrichment of the C₁₅ alkane and ring-opening and ring-hydrogenation products. The cracking, ring-opening, and ring-hydrogenation reactions were promoted at elevated reaction temperatures with a significant amount of lighter alkanes.