A Strategy for the Furfuryl Alcohol Oligomer Synthesis over Tungsten Oxide Catalyst

The conversion of renewable biomass into fuels and chemicals has been investigated as a result of increasing demand for petroleum oil and environmental pollution. Furfuryl alcohol (FA), which is produced from furfural derived from a selective dehydration of xylose, is an attractive intermediate chemical for the production of various chemicals, such as levulinic acid and FA polymer (FAP). FAP can be easily produced from FA monomer using strong mineral acid, such as H₂SO₄, and can produce ordered carbons through the pyrolysis, vapor deposition and carbonization methods. Although homogeneous catalysts showed higher conversion of FA to oligomers/polymers with hydrothermal treatment, these should be replaced by heterogeneous catalysts due to the issue of catalysts recycling and separation. The feasibility of using Tungsten Oxide (WO₃) catalysts were investigated in the FA oligomerization reaction in the liquid phase under mild experimental conditions, 100⁰C and ambient pressure. Five dimers (2,2’-Difurylmethane, 2-(2-furylmethyl)-5-methylfuran, Difurfuryl ether, 4-Furfuryl-2-pentenoic acid γ-lactone, 5-Fufuryl-furfuryl alcohol) and two trimmers (2,5-Difurfurylfuran and 2,2’-(Furylmethylene)bis(5-methylfuran)) were observed in GC and GC/MS measurement. The FA oligomers were further separated with unreacted FA monomer through liquid-liquid extraction using deionized water. Drying agent, Anhydrous Sodium Sulfate, was used to remove water in the isolated aqueous layer in order to recycle unreacted FA monomer. Purified FA oligomers can be used to produce alternative C9-C15 biofuel with further hydrodeoxygenation (HDO) reaction.