Intensified downstream processing for bioenzymatic HMF valorization

Abstract

The industrial viability of bioenzymatic production pathways for value-added chemicals relies on the development of energy-efficient and economically feasible downstream processes. This study presents the design, simulation, and techno-economic assessment of a novel downstream separation and purification process for the bioenzymatic conversion of 5-hydroxymethylfurfural (HMF) into four value-added products, namely: 2,5-bis(hydroxymethyl)furan (BHMF), 5-(aminomethyl)-2-furanmethanol (AMFM), R-1-phenylethylamine (R-PEAM), and S-1-phenylethylalcohol (S-PEA). The newly proposed process integrates a heat pump-assisted vacuum distillation column (supplying 5.38 MW_th to drive water evaporation) with pinch-optimized heat exchanger networks, reducing the heat pump system's total cost of ownership by 3% relative to a classic 10 °C minimum temperature approach design (44.31 vs. 45.67 M$). Alternative separation routes for the amine products and their process intensification via dividing wall column (DWC) were systematically evaluated against the base case across economic and environmental metrics. The DWC implementation of Route 2 (Case c) achieved high amine recovery (>99.88%) at the production cost of 42.94 $/kg of pure product and lowest pollutant and toxic materials emissions of 0.469 kg_pt/kg_product, although at a marginal increase in material intensity (0.0425 vs. 0.0420 kg_waste/kg_product) relative to the base case. All four products were obtained at purities exceeding 98%wt for BHMF and 99.9%wt for the remaining products. Economic feasibility is primarily determined by the price ratio of AMFM to phenylsilane feedstock, with AMFM currently priced significantly above the estimated production cost. This work demonstrates that heat pump integration and process intensification via DWCs offer measurable (but system-specific) advantages for bioenzymatic downstream processes, providing a quantitative basis for industrial scale-up decisions.