Batch and continuous flow hydrodeoxygenation of furfural and acetone condensation adduct catalyzed by Ni/ZrO2-SiO2

Furfural is one of the promising precursors obtained from dehydration and hydrolysis of hemicellulose. Condensation reaction of furfural and acetone gives furfurylidene and difurfurylideneacetone in 96% yield by reflux. The conjugated system between C=C and C=O bond in furfurylidene skeleton provide a new challenge for hydrodeoxygenation (HDO) reaction to produce alkane derivatives as alternative liquid fuels. Here we report the continuous flow method compared with batch reaction for HDO reaction of furfurylidene acetone catalyzed by Ni/ZrO2-SiO2. The Ni loading is 10% and 20% by weight of ZrO2-SiO2. The batch reaction was carried out using 10% Ni/ZrO2−SiO2 at 200 °C for 8 h gave alcohol and alkene with 100% conversion. The product was detected as 2-octanol (88.2%) and 6-dodecene (2.9% yield) based on gas chromatography analysis. In comparison, reaction using continuous flow reactor at same temperature using 10% Ni/ZrO2−SiO2 gave 2-((E)-but-2-enyl)furan (9.4%) and 2-butylfuran (4.6%). Here, we subjected that batch reaction leading to ring opening/hydrocracking products gave linear alkene/alcohol. Continuous flow reaction gave furanyl derivatives by hydrocracking reaction.