Two-Step Production of a Furfural-Derived Biosolvent in a Single Reactor: an Economic and Life Cycle Assessment Study

Abstract

In this study, we investigated the credentials of furfural as a building block for producing 5-methyl-1-(tetrahydrofuran-2-yl)hexan-3-one (THF-ALD-1), a prospective biosolvent. The process consists of two steps: (1) aldol condensation-crotonisation of furfural with methylisobutylketone (MIBK) to generate (E)-1-(furan-2-yl)-5-methylhex-1-en-3-one (ALD-1), and (2) selective hydrogenation of ALD-1 to THF-ALD-1 in MIBK. We conducted a comparative techno-economic analysis (TEA) and life cycle assessment (LCA) to evaluate the potential benefits of process intensification in a single reactor over a bifunctional 5%Pd/Al2O3 catalyst compared to a two-reactor process employing two catalysts—Al2O3 for the aldol condensation-crotonisation step and 5%Pd/Al2O3 for ALD-1 hydrogenation. A sensitivity analysis was performed to identify the key contributing factors and propose levers to reduce the cost and environmental footprint of THF-ALD-1 production. Our study demonstrates that a single-reactor process can offer 11% and 7.5% reduction of the full manufacture cost and minimum selling point, respectively, and lower environmental impact across all impact categories, with particularly significant benefits in terrestrial ecotoxicity potential (46%), freshwater ecotoxicity potential (15%), photochemical oxidant creation potential (22%), and acidification potential (21%). The furfural and MIBK market price fluctuation, overall yield, MIBK/furfural molar ratio, and number of Pd/Al2O3 catalyst regeneration cycles, are critical levers that influence fresh Pd demand, waste generation, and heat requirements for distillation. Optimisation of these parameters could yield potential cost benefits up to 20%, and mitigate by 32-36% the global warming potential, non-renewable energy use, and abiotic and ozone depletion potential.