A Comparative Evaluation of Particle Properties and Energy Demand for Biomass Comminution

Entrained-flow gasification is one of the most promising technological routes for efficient biomass conversion. A critical bottleneck restricting its rapid development lies in the efficient preparation of biomass powders. An ideal biomass powder preparation process should combine low energy demand with favorable particle properties conducive to conveying. However, direct comminution (DC) alone cannot meet these requirements. Here we systematically compare four comminution strategies─DC, multistage comminution (MC), screened comminution (SC), and blended comminution (BC)─and quantify the trade-offs among particle size distribution, morphology, bulk density, and energy demand for micron-scale feedstocks in entrained-flow gasification. MC produces moderate sphericity (0.60) and bulk density (273.2 kg/m3) but the broadest size distribution (span = 2.00); SC yields the narrowest size distribution (span = 1.34) at the cost of the lowest sphericity (0.50) and bulk density (223.8 kg/m3); BC achieves the highest sphericity (0.62) and bulk density (280.0 kg/m3), while DC falls between these extremes. In terms of comminution energy demand, MC, BC, and SC reduce the specific energy demand by 5.8%, 11.1%, and 41.0%, respectively, compared to DC (102.04 kWh/t). Energy allocation analysis reveals that heat loss from moisture evaporation accounts for 44.2–53.8% of the total energy input, underscoring the importance of predrying treatment. These findings highlight feedstock drying as a general principle for energy-efficient comminution, providing a quantitative framework for selecting comminution strategies based on specific industrial priorities and establishing a mechanistic basis for designing energy-efficient biomass pretreatment tailored to entrained-flow gasification.