Abstract Biomass and organic solid waste are increasingly recognized as promising renewable feedstocks capable of supporting a clean, carbon‐neutral energy infrastructure. Efficient conversion of these resources into high‐value secondary energy carriers is therefore essential to meet escalating global energy demands. Among these carriers, hydrogen stands out due to its high gravimetric energy density, exceptional purity, conversion flexibility, and compatibility with multiple end‐use technologies. This review provides a comprehensive assessment of emerging pathways and technological advances for producing hydrogen from biomass and organic solid waste. Recent progress in both thermochemical and biological conversion routes is critically evaluated. Thermochemical pathways—including gasification, pyrolysis, steam reforming, partial oxidation, and thermochemical cycles—are examined with respect to reaction mechanisms, process efficiency, and integration potential. Likewise, biological routes encompassing enzymatic hydrolysis, microbial and dark fermentation, and direct and indirect biophotolysis are analyzed for their scalability, yield limitations, and system optimization strategies. Key challenges related to feedstock variability, catalyst design, process intensification, and environmental impacts are discussed to illuminate the practical viability of hydrogen production within a bio‐based circular economy. The review highlights future research directions essential for advancing biomass‐ and waste‐derived hydrogen as a cornerstone of a sustainable hydrogen economy.
Vichitra et al. (Wed,) studied this question.