Impacts of water-organic solvents on polymerization of the sugars and furans in bio-oil

Abstract

Polymerization is one major issue during acid-catalyzed conversion of sugars/furans to platform chemicals. Reaction medium is one of the main factors impacting the tendencies of sugars/furans towards polymerization. In this study, conversion of sugars (fructose/glucose/xylose/xylan) and furans (hydroxymethylfurfural (HMF)/furfural/furfuryl alcohol (FA)) over a solid acidic resin catalyst in various water-organic bi-solvents (toluene, chloroform, n-butanol, tetrahydrofuran (THF), dimethyl sulfoxide (DMSO) and ethyl acetate (EA)) were investigated. The results showed toluene/chloroform as the co-solvent did not suppress the polymerization of fructose, HMF, furfural and FA while diminished the formation of LA from fructose/HMF. The organic co-solvents remarkably affected properties of the coke formed. The presence of aprotic organic solvents tended to retain the CO group in the coke formed and affected its thermal stabilities and evolution of the functionalities. Additionally, polymerization tendency of the furans with the distinct structures showed very different sensitivity with the water in reaction medium.