Production of a high carbon jet-fuel precursor from biomass derived furfural and 2-methylfuran using propylsulfonic SBA-15 catalysts

MARÍA SOLEDAD ZANUTTINI; LUCAS TONUTTI; PRISCILA QUARANTA; CLAUDIA NEYERTZ; CRISTIÁN FERRETTI; CARLOS QUERINI

Buenos Aires

Congreso; 11th World Congress of Chemical Engineering; 2023

Asociación Argentina de Ingenieros Químicos

According to the International Energy Agency, CO2 emissions by cars, vans and trains will cease by 2050, but heavy trucks, maritime transport and aviation emissions will still be more than 0.5 Gt of CO2. Therefore, it is imperative to develop routes for the production of biomass-derived C12-C15 molecules compatible with jet diesel. A C-C condensation process followed by hydrodeoxygenation (HDO) is required to achieve these biofuels. Among the alternatives, hydroxyalkylation-alkylation (HAA) reaction of furfural (FAL) and 2-methylfuran (2-MF) is the one of the best ones [1]. 2MF can be produced by a selective hydrodeoxygenation of FAL, which is obtained from nonedible biomass sources.In this work, the synthesis of jet fuel range branched cycloalkanes oxygenated precursors by solvent-free HAA of FAL and its hydrodeoxygenated product, 2-MF, is explored. The catalysts employed were SBA-15 silica functionalized with propyl sulfonic groups. These mesoporous materials have structural and acid properties that can be tuned by adjusting syntheses conditions. We modified the amount of propyl sulfonic groups, the hydrophobicity of the catalyst and process conditions to optimize the production of the 15-carbon fuel precursor. The subsequent hydrodeoxygenation of the C15 molecule to paraffins was not studied in this work. SBA-15 type silica was synthesized with 3 different loads of propyl sulfonic acid groups: 5, 10 and 15 mol%S/Si. The catalysts were labeled S5, S10 and S15 respectively. Loads greater than 15% were not used because a detriment in the ordering of the material was observed.These catalysts were characterized and tested in solvent-free liquid reaction at a similar acid sites/F molar ratio and the same conditions. After each reaction test, the sample was diluted 500 times in acetonitrile and analyzed by gas chromatography with an MEGA-1 column and an FID detector. Catalyst S15 showed the best results. The optimal conditions found were: furfural conversion of 99.4% and C15 yield of 97.4% at 60ºC after 2h of reaction with stoichiometric feeding of the pure reagents. In this case, a catalyst load of 0.7% of the total mass of reactants was employed. This value is compatible with the quantities used in the industry, indicating that this process is suitable to be scaled.Nevertheless, it was observed that water in the feed highly affects the performance of the catalyst. For this reason, modifications were done on the hydrophobicity. A new catalyst was synthetized by the incorporation of hydrophobic groups by co-condensation. This catalyst was labeled as S15S+H. Catalysts S15 and S15B+H were tested at the same conditions. With the latter, a 14.5% improvement was obtained. Regarding selectivity, no significant differences were observed between both materials.Finally, catalyst-recycling studies revealed that both catalysts, S15 and S15S+H, could be recycled 3 times with a minor reduction of activity.ISSN 2953-5565