Mechanism-driven energy optimization in compression molding of biomass waste for renewable material production

The compression molding of biomass waste into value-added products is energy-intensive, hindering sustainable application. This study investigates energy dissipation mechanisms and optimization for low-energy molding of biodegradable seedling containers from straw-potato residue. A nonlinear viscoelastic-plastic constitutive model was developed to deconvolute elastic, plastic, and viscous energy contributions. Grey relational analysis quantified parameter sensitivity, identifying wall thickness as the most critical factor affecting Specific Energy Consumption. Discrete element method simulations visualized microscopic force chain evolution, linking micro-mechanical interactions to macroscopic energy dissipation. Results reveal a shift in dominant dissipation pathways with moisture content and demonstrate that increasing wall thickness from 2 mm to 5 mm stabilizes force chains, reducing friction and breakage to achieve a 56.25 % SEC reduction. Optimal parameters (30 % moisture, 0.3–0.9 mm particle size, 5 mm wall thickness, 450 s dwell time) ensure minimal energy use while maintaining structural integrity, providing a multi-method framework for designing energy-efficient biomass valorization systems. • A novel multi-method framework quantifies energy dissipation in biomass molding. • Viscoelastic-plastic modeling decouples elastic, plastic, viscous energy components. • Grey relational analysis identifies wall thickness as the most critical parameter. • DEM simulations reveal how microscopic force chains govern macroscopic energy loss. • Optimal parameters achieve a 56.25 % reduction in specific energy consumption (SEC).