For the past several decades, various efforts have been made in using lignocellulosic biomass as a renewable source of energy and a potential subsitute for pretoleum based fuels and chemicals. In particular, biomass derived carbohydrates can undergo acid-catalyzed dehydration reactions in water to produce furanic compounds such as 5-hydroxymethyl furfural (HMF), which is considered a top value commodity chemical for the production of fuels, fuel additives, and plastics. Nonetheless, the process involves many side reactions that often require the addition of an organic solvent to the system in order to extract HMF from the aqueous phase and prevent its further degradation. While these biphasic systems fall short in the case of convential batch reactors that require a frequent recycling of the organic phase and large volumes of the organic solvent, continuous flow microreactors enable the formation of intricate and tunable two-phase flow patterns with large specific interfacial areas that provide mass transfer rates that are 2 â 3 orders of magnitude greater than their batch counterparts for rapid extraction of HMF with improved yield, selectivity, and process economics by means of process intensification.
In this work, we study and characterize the hydrodynamic and mass transfer properties of two-phase flow patterns in a biphasic microreactor. We conducted experiments for the extraction of HMF with various organic solvents and also performed the reactive extraction using various carbohydrate substrates and catalysts. For this particular case, we will present a study of the reactive extraction of HMF in a water/ethyl acetate capillary biphasic microreactor using fructose as the substrate and an HCl and KCl buffer solution as the catalyst. A hybrid first-principles and data-driven kinetic model of the reaction network in combination with a mass transfer model was also used to evaluate the optimal reaction and operation conditions that maximize HMF yield.