Mechanism of n-Hexane Insolubles in Biomass-Coal Co-Pyrolysis and Optimization of Their Mixing Ratios

This study thoroughly investigates the influence mechanism of n-hexane insolubles (INS) and their blending ratio on product yields during the co-pyrolysis of biomass and coal. First, Spearman's correlation coefficient analysis revealed intrinsic relationships between INS content and yields of tar, water, and char. Results indicate significant correlations between INS and tar/char yields, while its effect on water yield is negligible. Subsequently, to further elucidate yield variation patterns under complex operating conditions, variance analysis was employed to investigate the interactive effects of INS and blending ratios on product yields. Findings revealed that different INS-blend combinations significantly altered tar growth rates and coke residue decline trends. Building upon these findings, a nonlinear optimization model was constructed to maximize energy conversion efficiency and product utilization. The Sequential Quadratic Programming (SLSQP) algorithm was employed to identify optimal blending ratios and INS dosage under specified cost and technical constraints. The research outcomes provide scientific theoretical foundations and operational guidance for optimizing biomass energy utilization, enhancing energy efficiency, and achieving sustainable energy production.