Direct production of hydroxymethylfurfural from raw grape berry biomass using ionic liquids and metal chlorides

Abstract

We report for the first time the direct conversion of raw grape berry biomass to hydroxymethylfurfural (HMF) using ionic liquid solvents with metal chloride catalysts. Exploiting raw plant biomass as a biorefinery feedstock is innovative for sustainable chemical industry. The use of the raw biomass to synthesize compounds can indeed lead to less energy consumption and less CO₂ emissions. Using raw plant biomass skips pretreatment steps that are required to produce biomaterials such as carbohydrates or cellulosic biomass. Here, grape berry biomass was used as a raw chemical feedstock for the production of hydroxymethylfurfural, a key platform intermediate for syntheses of future renewable biofuels. We examined 3 ionic liquid solvents, 3 reaction temperatures, 5 chloride catalysts, and 5 concentrations of HCl. We found an increasing HMF yields depending on reaction conditions. 1-octyl-3-methylimidazolium chloride was most effective for HMF synthesis. Addition of HCl or metal chlorides alone showed little improvement. The highest HMF yield of about 100 mg HMF per mL of grape biomass extract was obtained using 0.3 M HCl, [OMIM]Cl, and CrCl₂ at 100°C for 3 h. Our study provides a model system of sustainable production of valuable compounds from raw plant biomass.