Catalytic Co-Pyrolysis of Biomass and Plastic Waste: A Comprehensive Review

Abstract

Catalytic co-pyrolysis of biomass and plastic waste has gained significant attention as a strategically important thermochemical route for converting heterogeneous waste streams into high-value fuels and carbonaceous products. Recent advances demonstrate that the integration of suitable catalysts can substantially enhance product quality by promoting hydrogen transfer reactions, accelerating deoxygenation pathways, and facilitating the selective cracking of macromolecular intermediates. These catalytic effects not only enrich bio-oil with hydrocarbons and reduce oxygenated compounds but also improve syngas composition and tailor the structural properties of resultant chars for functional applications. This review synthesizes recent advancements in catalyst design, reaction mechanisms, synergistic effects, and reactor configurations. Special emphasis is placed on hydrogen donor interactions, deoxygenation mechanisms, and catalytic cracking behavior. Challenges related to catalyst stability, process scaleup, and technoeconomic feasibility are discussed, along with future research pathways.