Study of Liquid Alkanes Production from Biomass-Derived Carbohydrates by Aldol-Condensation and Hydrogenation Processes

Abstract

This research aims to synthesis liquid alkanes from biomass-derived hydroxyl methyl furfural (HMF) and furfural by aldol-condensation and hydrogenation processes over several catalysts i.e. TiO₂, TiO₂-ZrO₂, Pd/Al₂O₃ and Pd/CeO₂. It was found that the catalysts make significant impact on the selectivity and yield of alkanes product. It is noted that Pd/Al₂O₃ provided the highest alkane yield and selectivity. The aldol-condensation and hydrogenation of HMF over Pd/Al₂O₃ provide high C12 selectivity whereas the aldol-condensation and hydrogenation of furfural over Pd/Al₂O₃ provide high C8 selectivity. The effects of reaction temperature, reaction pressure and reaction time were then studied. The effect of inlet furfural to acetone molar ratio was also determined. It was also found that the optimized conditions to maximize the yield of alkane production from the aldol-condensation/hydrogenation of HMF and furfural are (i) at 53^oC and 24 hr for aldol-condenstation of HMF, (ii) 80^oC and 24 hr for aldol-condenstation of furfural, and (iii) 120^oC for 6 hr with HMF to acetone molar ratio of 3:1 and furfural to acetone molar ratio of 4:1 in the presence of Pd/Al₂O₃ (calcined at 500^oC) for hydrogenation reaction.