A critical review on pyrolysis of maize biomass for bio-oil and biochar production with its potential outcomes

Abstract This review offers an in-depth analysis of pyrolysis as a sustainable route for converting corn-based biomass including corn stover, corn cob and corn stalk into valuable bio-oil and biochar. Amidst the growing demand for renewable and environmentally friendly energy alternatives, corn-derived agricultural residues have gained attention as attractive feedstocks due to their widespread availability, cost-effectiveness and ecological advantages. Although various conversion pathways such as chemical, biochemical and thermochemical have been explored, pyrolysis stands out as the most extensively investigated and efficient thermochemical method. Drawing from existing literature, this study systematically evaluates a range of pyrolysis techniques including slow, fast, catalytic, hydro-pyrolysis and microwave-assisted processes. The analysis underscores the significant impact of operational parameters and reactor design on product yield and composition. Nevertheless, key challenges such as catalyst deactivation, process optimization and scalability continue to hinder the commercial adoption of some pyrolysis approaches. By highlighting these issues, the review pinpoints current research gaps and proposes future directions aimed at improving process efficiency and product selectivity. In addition, the review incorporates a sustainability perspective through the lens of life cycle assessment (LCA) offering insights into the environmental impacts, carbon footprint and resource efficiency of bio-oil and biochar production from corn-based biomass. Ultimately, this comprehensive overview serves as a roadmap for advancing pyrolysis technologies toward large-scale and sustainable biofuel production from corn-based biomass.