New bio-aviation fuel production from 2-methylfuran and methyl isobutyl ketone using mesoporous sulfated SBA-15 catalyst

This study demonstrates the synthesis of a new C₁₆ branched bio-aviation fuel precursors (5,5'-(4-methylpentane-2,2-diyl)bis(2-methylfuran), abbreviated as MPM) from lignocellulose derivatives via hydroxyalkylation/alkylation (HAA) of 2-Methylfuran (2-MF) with Methyl Isobutyl Ketone (MIBK) using sulfated SBA-15 catalyst (S-SBA-15). The SBA-15 was synthesized and subsequently functionalized with sulfate groups (-SO₄^2-) for the first time using ammonium sulfate with various concentrations of 0.5, 1, and 2M. Among all catalysts, S-SBA-15-1M exhibited the highest conversion of MIBK (78 %) and MPM yield (47 %). S-SBA-15-1M is a mesoporous material which has hexagonal p6mm structure with a surface areas of 341 m²/g, a pore size of 6.8 nm, acidity of 1.9 mmol H⁺/g. The combination of its high mesoporosity and high acidity outperformed other S-SBA-15 catalysts. The reaction condition for HAA of 2-MF and MIBK was varied and the highest MIBK conversion (99 %) and MPM yield (62 %) was achieved at 4 to1 molar ratio of 2-MF to MIBK, a reaction temperature of 90 °C, 5.4 wt% catalyst loading and 24 h reaction time. The chemical structure of MPM was confirmed for the first time with GC-MS, ¹H NMR, and ¹³C NMR. This study provides a new insight into the synthesis of a new bio-aviation fuel precursor via HAA of 2-MF and MIBK. The MPM was then converted into a new C₁₆ branched alkanes via hydrodeoxygenation (HDO) reaction using commercial ruthenium-based catalyst.