Hydrogen is emerging as a cornerstone of the global clean energy transition, yet sustainable production pathways remain a major challenge. This review provides a comprehensive and comparative assessment of catalytic and non-catalytic biomass conversion technologies, including pyrolysis, gasification, and supercritical water gasification, for hydrogen-rich syngas production. Unlike previous reviews focused on individual processes, this work uniquely integrates the thermochemical fundamentals, catalytic mechanisms, and reactor configurations that govern hydrogen selectivity. Particular emphasis is placed on the effects of process parameters such as temperature, pressure, residence time, gasifying agents, and catalyst loading on syngas composition and yield. Emerging technologies such as microwave-assisted, plasma-assisted, and hybrid pyrolysis–gasification systems are critically analyzed for their potential to enhance process efficiency and hydrogen purity. Moreover, this review pioneers the discussion of artificial intelligence (AI)-driven modeling and optimization frameworks for predicting and improving biomass-to-hydrogen conversion performance. A techno-economic and life cycle assessment (LCA) perspective is presented, demonstrating that biomass-derived hydrogen can achieve low or even negative carbon emissions with carbon capture and renewable energy integration. By consolidating recent advances and identifying persistent challenges in catalyst stability, reactor scalability, and system integration, this review outlines a strategic roadmap for advancing biomass-based hydrogen technologies toward commercial deployment and a sustainable hydrogen economy. • Advances in biomass pyrolysis and gasification for hydrogen. • Catalytic systems enhance hydrogen yield and syngas quality. • Co-feeding waste improves efficiency and resource utilization. • Emerging reactor designs boost process sustainability and scalability. • Techno-economic and environmental analyses confirm commercial potential.
Razzak et al. (2026) studied this question.