Green synthesis of 5-hydroxymethylfurfural through non-catalytic conversion of glucose in a microreactor

5-hydroxymethylfurfural (HMF) is an essential platform chemical that can be transformed into various high-value-added products. Most of the 5-HMF production nowadays involves the use of catalyst, which significantly contributes to the production cost as well as the environmental problem concerning highly acidic compounds. Moreover, the low 5-HMF yield has been recognized as a bottleneck, reducing its attractiveness. In this work, the enhancement of continuous green synthesis of 5-HMF from glucose in a biphasic microreactor was proposed. Methyl isobutyl ketone (MIBK) was used as an organic solvent to prevent further reactions of 5-HMF into undesired products. The main and interaction effects of reaction temperature, residence time, and organic-to-aqueous volumetric ratio on 5-HMF yield were studied. The 5-HMF yield of 69.5% and 5-HMF selectivity of 77.9% were achieved at the reaction temperature of 190 °C, residence time of 134 mins, and organic-to-aqueous volumetric ratio of 0.5:1. The kinetic parameters were estimated to predict the concentration profiles. It was found that our environmentally-friendly process provided a similar yield of 5-HMF compared to those of the conventional techniques (literature data).