Effects of particle size refinement, moisture content optimization, and poplar bark additive on the quality of bamboo-formed pellet fuels

This study investigated the effects of particle size, moisture content, and poplar bark additives on the quality of bamboo biomass pellets using waste bamboo sawdust from Zhejiang Province. Moisture content was systematically divided into six intervals (2%–12%) and particle size into five fractions (0–2 mm). Through single-factor and orthogonal experiments combined with scanning electron microscopy analysis of particle interfacial bonding mechanisms, we comprehensively evaluated pellet density, mechanical durability, and calorific value. Single-factor experiments showed progressive increases in density and mechanical durability as moisture content rose from 2% to 6%, followed by decreases at 12% moisture. Pellet quality improved holistically with poplar bark additive incorporation. Orthogonal experiments analyzed the effects of particle size and moisture content on pellet formation. Results demonstrated that moisture content significantly affected both density and mechanical durability, while particle size primarily influenced density. The additive counteracted moisture effects on density and the combined particle size–moisture effects on durability, expanding optimal parameter thresholds. This research provides guidance for improving the utilization efficiency of bamboo processing waste.