Comparative Techno-economic, Uncertainty and Life Cycle Analysis of Lignocellulosic Biomass Solvent Liquefaction and Sugar Fermentation to Ethanol

This study compares the use of three low boiling point polar aprotic solvents, tetrahydrofuran (THF), acetone, and 1,4-dioxane, for extracting biomass sugars in ethanol biorefineries. The techno-economic analysis employs experimental data to build a chemical process model and estimate capital and operating costs of a commercial-scale biorefinery. The biomass solvent liquefaction in a 2000 metric tonne per day sugar fermentation biorefinery yields ethanol at minimum fuel-selling prices (MFSP) of $2.98 to $4.06 per gallon. THF achieves the lowest MFSP. Uncertainty analysis indicates that solvent to biomass ratio, glucose and xylose yields, feedstock price, and capital costs are the primary drivers of the ethanol MFSP. The 10% to 90% percentile for THF-based ethanol MFSP are estimated to be $2.31 and $3.21 per gallon. Life cycle analysis shows that with a lower solvent to biomass ratio as suggested by previous studies, our process could achieve GHG emissions reduction of 25% and 45% for THF and acetone cases...