Synthesis of furfural from xylose using a choline chloride-based deep eutectic solvent and mechanistic insights

Abstract

The exacerbated use of fossil resources, along with the fact that these materials are raw materials from a non-renewable source, has caused a worldwide concern for their replacement. In view of this, biomass is identified as the best renewable raw material option to replace these materials in the production of energy, fuels and chemical products. Among the substances that can be obtained from biomass, furfural as a platform molecule deserves to be highlighted as it can facilitate the access of numerous substances useful for the society. Therefore, in this study, a green methodology was developed for the synthesis of furfural. For this, a biphasic system was used, where the reaction phase consisted of an acid deep eutectic solvent (DES) based on choline chloride ([Ch]Cl), water, p-toluenesulfonic acid (PTSA) and xylose and the extractor phase consisted of ethyl acetate. Using this system, it was possible to obtain furfural with a yield of 50% by heating the mixture at 130 °C for 15 min in a microwave reactor. Finally, the results presented were promising, with potential as a basis for the development of methods for the synthesis of furfural in biorefineries using DES, and, in addition, a discussion is carried out on the mechanistic route that leads to the formation of furfural.