Emerging approaches on biomass and water-based hydrogen production and downstream recovery pathways: a review on recent challenges and prospects

Transitioning towards a low-carbon society can be accelerated by producing clean hydrogen fuels from sustainable resources, such as biomass and water, thereby offering a sustainable energy source that effectively reduces greenhouse gas emissions. This review provides a comprehensive analysis of hydrogen production technologies, including fossil fuel-based processes (e.g., thermochemical conversions and steam methane reforming), electrolysis-based routes (alkaline, polymer electrolyte membrane, and solid oxide water), and biological methods (dark fermentation, photofermentation, and biophotolysis), along with emerging photocatalytic and photochemical systems. For each pathway, we critically assess its technological maturity, deployment status, and potential to enhance the share of clean energy in the global renewable energy supply chain. The manuscript also highlights research gaps, prospects, and challenges for numerous upstream hydrogen generation from both biological and non-biological sources, with a specific focus on enhancing efficiency, reducing costs, and improving environmental performance. Photochemical, electrochemical, and photocatalytic hydrogen generation systems utilizing biomass and water as feedstocks have garnered significant attention. Technological advances in the downstream enrichment and storage of hydrogen gas are critically evaluated, including opportunities, current challenges, and barriers associated with commercial applications. Metal–organic framework-based pressure swing adsorption, electrochemical hydrogen pumps, and metal hydrides are analyzed for their capacity to achieve high hydrogen purification (~ 99.99%) and enable a scalable storage solution. However, the economic and commercial feasibility of hydrogen production from biomass remains a substantial challenge due to the high production cost ($4.11–$7.45/kg H₂). This can be alleviated by appropriate biomass selection, the development of highly selective catalysts, the integration of different processes, and the application of artificial intelligence-/machine learning-driven models to predict the outcomes for better industrial automation. This study offers insightful information for the selection of highly effective and advanced hydrogen generation, purification, and storage techniques. We conclude with strategic recommendations for technology development, scale-up efficiency, and policy frameworks that can expedite the transition to a sustainable hydrogen economy.