Selective fructose dehydration to 5-hydroxymethylfurfural from a fructose-glucose mixture over a sulfuric acid catalyst in a biphasic system: Experimental study and kinetic modelling

A two-step process combining the (equilibrium) glucose isomerization to fructose with selective dehydration of in obtained sugar mixture 5-hydroxymethylfurfural (HMF), where is largely unconverted and recycled, represents an attractive concept increase overall efficiency for HMF synthesis. This work presents experimental modelling studies on conversion such fructose-glucose using sulfuric acid catalyst a water-methyl isobutyl ketone biphasic system under wide range conditions (e.g., temperature, concentrations). Through detailed product analyses ESI-MS spectroscopy, excess formation formic (together humins) by direct sugar/HMF degradation was confirmed included reaction network (neglected most literatures). The kinetic based batch experiments monophasic water well describes measurements thereof, whereas distinct deviations were found prediction typical literature models. incorporation equilibrium extraction into developed model, consideration phase volume change as function temperature partial miscibility, enables predict results batch. model allows optimize synthesis that are favored continuous reactors minimized back mixing. Based implications, optimized slug flow microreactors better address intensification scale-up aspects. Using simulated feedstock represent commercially available high corn syrups, maximum yield 81% at 155 °C over 0.05 M H2SO4 residence time 16 min microreactor, 96% 95% remaining unconverted.