A Critical Review of Hydrogen Production Technologies: Comparative and Integrative Analysis From Industrial Processes to Emerging Low-Carbon Pathways.

The global transition toward low-carbon energy systems is constrained by the carbon intensity and scalability limitations of current hydrogen production technologies. Although hydrogen is widely recognized as a clean energy carrier, the absence of an integrated and comparative framework limits its system-level optimization. This review presents a critical assessment of hydrogen production technologies encompassing industrial processes, biomass, and electrochemical pathways. Conventional processes are analyzed across decarbonization strategies, while biomass-derived electrochemical pathways are evaluated for feedstock flexibility and life-cycle emission advantages. Advanced technologies, including thermochemical water-splitting cycles, plasma-assisted reforming, solar-driven thermochemical processes, photocatalytic and biological routes, are critically examined with respect to scalability, materials limitations, and system integration challenges.