Hierarchical zeolite catalysed fructose dehydration to 5-hydroxymethylfurfural within a biphasic solvent system under microwave irradiation

Realising sustainability within the chemical industry necessitates a shift from the traditional linear approach, based on crude oil, to a circular economy using alternative feedstock such as biomass, from which 5-hydroxymethylfurfural (HMF) is a potentially highly interesting platform chemical. While its production is relatively straightforward via the dehydration of fructose, derived from either saccharides or lignocellulosic biomass, its production is hindered by undesirable side reactions, which decrease the selectivity of the intended reaction to HMF, hence diminishing the overall yield. Here we report a green, highly selective approach to producing 5-hydroxymethylfurfural (HMF) from fructose based on the co-deployment of a biphasic reaction medium, microwave radiation, and a commercial solid acid catalyst (FAU Y zeolites). Following an initial evaluation of catalyst-solvent interactions and diffusion, a hierarchical mesoporous Y zeolite was chosen and deployed within a range of reaction media and process conditions for process optimisation, identifying a biphasic system consisting of ((6 : 4 water : DMSO)/(7 : 3 MIBK : 2-BuOH)) as the optimal reaction medium. This solvent combination facilitated an HMF yield of similar to 73.9 mol% with an excellent selectivity of similar to 86.1% at 160 degrees C after only 45 minutes under microwave irradiation. These, in turn, result in optimal energy efficiency and excellent green credentials relative to conventional heating. The aqueous catalytic dehydration of fructose to HMF over Y zeolite in a DMSO water reaction phase under microwave irradiation is followed by subsequent product extraction into an organic phase for optimal HMF yields through reduced humin formation.