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

Abstract

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, respectively. Further optimization of the process could lead to significant reductions in ethanol costs, commercialization risks, and GHG emissions.

A critical review of life cycle assessment studies of woody biomass conversion to sugars

“…[ 32 ] glucose/hemicellulose/lignin, bioethanol/lignin/furfural organosolv beech woodchips 1 t h −1 hardwood chips ✓ Li et al . [ 33 ] bioethanol dilute sulfuric and organic acid forest residues 1 MJ ethanol Moncada et al . [ 34 ] glucose production organosolv spruce woodchips 1 kg of dry glucose ✓ mass/energy flows Bright & Strømman [ 35 ] bioethanol dilute sulfuric acid poplar chips 1000 km distance Mu et al .…”

The Roles of H2O/Tetrahydrofuran System in Lignocellulose Valorization

“…Levoglucosenone (LGO), an anhydro-sugar with a double bond combined with a ketone and aldehyde, in addition to two hydroxyl groups (Tang et al, 2017b;Krishna et al, 2018), has shown a huge potential to serve as a bio-based platform chemical (Nguyen et al, 2015;He et al, 2017a;Li et al, 2018). Cao et al (2015) found that the highest yields of LGO could be obtained in both THF and GVL aqueous co-solvents.…”

“…Liquefaction in the presence of solvent has been considered as an efficient approach for the production of valuable chemicals or biofuels from lignocellulose, since solvents significantly improve the mass and heat transfer of solid lignocellulosic biomass (Li et al, 2018). Compared to pyrolysis, solvent liquefaction requires relatively moderate reaction temperature.…”

Production and purification of crystallized levoglucosan from pyrolysis of lignocellulosic biomass

“…The methanol recovery rate is assumed to be 99%. 36 We estimate the methanol recovery cost to be $7 per MT of methanol based on work by Shahandeh et al 37 This cost includes the annualized capital and operating costs of the distillation process.…”