Biomass Processing and Product Recovery, Project No. 2. Interim Progress Report. Cooperative Research and Training in Biomass Conversion and Utilization

摘要

The goal of this research is to identify and explore some of the considerations in solvent extraction of ethyl alcohol from fermented wood hydrolyzate. The objectives of the experimental work was to provide batch and cross-current extraction data on common organic solvents and the fermentation broth. The data were necessary to validate the LLEXT program. Beer solutions were prepared in the laboratory to simulate the fermented wood hydrolyzate of southern red oak hardwood. Results show that: batch and cross-current solvent extractions can be simulated successfully using the LLEXT program which incorporates the UNIFAC free-energy model; extractions involving alkanes and aromatics were determined by simulations to rate unsatisfactory at ethyl alcohol recovery, but superior in water rejection and solvent losses; extraction simulations involving acetate solvents rated satisfactory at ethyl alcohol recovery, superior at water rejection and unsatisfactory at solvent losses; a solvent number can be used to predict the optimum number of cross-current solvent extraction stages, considering ethyl alcohol recovery and water rejection only; of the acetates considered as solvents only ethyl acetate and isobutyl acetate had relatively low costs; ethyl acetates boiling point is too low for good separation and recovery of ethyl alcohol via distillation of the extraction product; little or no ethyl alcohol can be separated from isobutyl acetate and MEK extracts in simulated distillations using the parameters specified; the majority of furfural and acetic acid remained with the solvent in the bottoms during simulated distillation using isobutyl acetate and MEK extracts; and simulated distillation of the standard fermentation beer using the parameters specified predicted a product containing less than 6 mole % ethyl alcohol. 4 references, 4 figures, 4 tables. (ERA citation 09:028045)