Application of fluid rheology models for milled woody biomass and non-recyclable municipal solid waste particles

Abstract

Biofuels from biomass and non-recyclable municipal solid waste (N-MSW) can potentially replace aviation fossil fuels. However, the cost-effectiveness is impeded by feedstock handling issues, such as unstable flow or jamming in hoppers and feeders. This issue can be solved mainly based on enhanced understanding of the rheology of biomass and N-MSW particles, which remains poorly understood. Leveraging discrete and continuum-based granular rheology models, in this study, we conduct industry-scale hopper flow testing of milled woody biomass, paper, cardboard, foam, thin film, and plastic particles, and investigate the potential of using fluid rheology models to characterize the hopper flow behavior. The hopper flow tests demonstrate different flow behaviors of tested materials, including fast flow, stable-to-unstable flow, and varying flow rates. Numerical simulation of hopper flow tests utilizing the Gudehus-Bauer hypoplastic model demonstrates good agreement with experimental data for the biomass and rigid plastic particles, and those using non-Newtonian fluid models exhibit promising agreement with experimental data with low computational cost. However, new fluid rheological models are required to capture the unstable and varying rate flows of highly compressible particles such as paper and foam. This study advances the knowledge on the rheology of particulate biomass and N-MSW materials for biofuel production.