Synergistic effects of biochar from the co-pyrolysis of lignocellulosic biomass and typical biomasses: mechanism of action and key parameters.

Biomass waste is a promising renewable feedstock, and pyrolytic conversion into biochar brings prominent economic and environmental benefits. Co-pyrolysis enables simultaneous waste recycling and produces synergistic interactions to improve biochar yield and quality under optimized thermal conditions. This review critically summarizes quantitative and mechanistic research methods of co-pyrolysis synergies, focusing on biochar production from co-pyrolysis of lignocellulosic biomass (LB) and other biomasses; such synergies originate from complementary compositions among diverse raw materials. The direction and magnitude of synergistic effects depend on feedstock properties, operating parameters and reactor styles. Primary synergy pathways include free-radical reactions, metallic catalysis and mineral-mediated mineralization, with pyrolysis temperature, blending ratio, residence time and heating rate as key parameters. Comparative analysis indicates screw reactors and rotary kilns benefit from uniform raw material mixing and suit large-scale biochar manufacturing. Future work is recommended to integrate artificial intelligence and multi-scale simulation to facilitate the engineered, customized and functional industrialization of co-pyrolysis-derived biochar.