(332e) Advancing Forest Biorefineries Towards Commercial Applications through Preprocessing of Biomass Wastes

The Forest Bioproduct Research Institute (FBRI) at the University of Maine has been demonstrated the acid hydration and dehydration (AHDH) of lignocellulosic biomass to fuel intermediates at a one-ton-per-day pre-commercial pilot plant. In the AHDH process, cellulose is converted to levulinic, and formic acids and hemicelluloses are converted to furfural. The integrated AHDH process consists of sawdust preprocessing, conversion of forest residues to organic acids (levulinic and formic acids), biochar separation, and separation of organic acids. For the last few years, the FBRI has experienced a wide number of challenges while demonstrating the unit processes in each process area. The FBRI has collaborated with the Idaho National Laboratory to address these challenges through preprocessing and establishing the critical material attributes of forest residues. A combination of bench and pilot scale experiments coupled with computational modeling are employed to study the effect of feedstock composition, particle size, bulk density, moisture content, and particle size distribution on the feedstock flow flowability and the feedstock conversion to organic acids. The preliminary results have indicated that particle size has little importance on the effectiveness of a strong acid pretreatment step and the organic acid yields. Further it is found that the loss of mannan and galactan of forest biomass must be reduced in the chemical preconditioning of forest residues. Finally, the initial cold flow tests at pilot scale have indicated that the presence of fine particles aid flowability of forest biomass slurries in progressive cavity pumps.