Modelling, optimal solvent screening and separation of 5-hydroxymethylfurfural or furfural from catalytic conversion reactor stream in downstream purification process

An overall process evaluation-based solvent selection for the biphasic catalytic conversion of the sugars into bio-based 5-hydroxymethylfurfural (5-HMF), furfural (FURF) and for the downstream separation and purification sequence was carried out, which represents an important step in industrial operating procedure. In the chemical process screening for 5-HMF extraction, the various dissolving fluids of different molecular polarity were used, parallel batch experiments were performed, and a few were identified as potential substance solutions for either, 5-HMF or FURF. Criteria were based on the ability to form two liquid phases within an aqueous thermodynamic system, to have fast transport kinetics, and simultaneously extract the 5-HMF and/or FURF with a high partitioning coefficient. The feasibility of the constituents’ pure mixture in terms of waste material efficiency, its resource recovery and the purity of both product species were also a part of the criteria. The best solute-partitioning alternatives found, besides an organic benchmark methyl isobutyl ketone (MIBK), were benzyl alcohol, tetrahydrofuran (THF) with an addition of sodium salt and homologues, resulting from the determined efficacy analysis, modelling and optimisation of the continuous purification methodology by means of partition, distillation and thermal heat recuperation. This allows for designing a diluted carbohydrate stream integrated bio refining in the wake of pulping.