(193c) Air-Classification of Forest Residues for Beneficiated High Temperature Conversion Feedstock

Economic viability of current pathways to renewable fuels and materials relies on the utilization of all available biomass resources including residues and low-cost materials. These low-cost resources such as the tops, limbs, and other wood waste after lumber harvest or milling operations, construction and demolition debris, industrial and residential residues, etc. These wastes, however, often have deleterious composition/properties for subsequent upgrading to fuels or products. There are many potential treatments to beneficiate feedstock prior to downstream utilization, and this work investigates using air-classification and other density-based separations to separate the feedstock down to tissues with differential anatomical function. Separation of these materials can improve the product yield, quality, and overall process economics of thermochemical conversion of biomass. This work also presents how these fractionation methods impact and control the feedstock material attributes. Material attributes related to the classification efficiency include particle size, size distribution, particle density, morphology, and moisture content. These properties alter the drag and hydrodynamics of the particles and ultimately impact the separation efficiency. These results and properties are also investigated in a preliminary discrete element modeling effort to understand the separations from a first-principles perspective.