(23b) Experimental Study of Intermediate Storage and Discharge of Compressible Biomass Particulate Solids in a Wedge-Shaped Hopper of Changing Geometry

Many challenges are associated with the granular flow (reliable transport) of compressible biomass through biorefinery unit operations (hoppers, silos, screw conveyors, etc.) arising from the material’s elasticity, compressibility and cohesive nature. The storage and intermittent discharge from hoppers or bins, for example, varies dependent on bin size, slope, material of construction, discharge opening, time-consolidation, etc. This talk will present extensive experimental investigation of the flow behavior (resulting from shear-failure of the bulk sample) of an industrially relevant mature loblolly pine that was grown in established plantations and corn stover in a pilot scale wedge-shaped hopper in relation to the design configuration. In this work, discharge opening, wall lining material, hopper semi-angle, and material height relative to discharge/recycle during dynamic tests are investigated for two different biomass samples. Static tests investigating the time- and stress-consolidation impacts on critical arching distance will also be presented. This work is an experimental investigation and validation of biomass flow behavior for pilot scale equipment, and can also be used to verify particle-scale DEM or FEM models. Accurate measurement and representation of these materials in intermediate storage and feeding bins is essential to ensure uniform handling of biomass and prevent issues of segregation, agglomeration, plugging, ratholing, stagnant material, arching, etc. This talk will also present preliminary linkages to coupled modeling effort at Idaho National Laboratory.