Preparation of bio-carbon by polymerization of bio-tar: a critical review on mechanisms, processes, and applications

Abstract

Biomass pyrolysis serves as a pivotal technology in renewable energy development, yet persistent bio-tar formation remains a critical challenge in pyrolysis processes. The innovative strategy of converting bio-tar into bio-carbon presents a promising pathway for technological advancement. To assess the efficacy and value of this approach, a comprehensive analysis of existing research advancements is warranted. This review systematically elucidates the polymerization mechanisms, polymerization process regulation, and application potential of derived bio-carbon. Notably, oxygenated compounds containing carbonyl groups and furan rings serve as critical precursors in bio-tar polymerization, where their unsaturated oxygen-containing functional groups facilitate bond cleavage and recombination. The main methods for regulating polymerization were analyzed by considering interactions between multiple influencing factors during polymerization. Reaction parameters significantly modulate bio-carbon yield by altering bio-tar component states and polymerization reaction, while additive incorporation enhances the physicochemical characteristics of bio-carbon. Crucially, bio-carbon produced through secondary biomass thermoconversion emerges as a novel carbon material, with its primary applications focusing on high-performance carbon material synthesis via value-added utilization pathways. This work establishes a theoretical framework for both bio-tar treatment and advanced carbon material development, offering systematic insights into polymerization mechanisms and application prospects.