Hydrogen Production Methods: Carbon Emission Comparison and Future Advancements

Hydrogen is emerging as a key energy carrier in the transition toward a low-carbon economy, however, the associated environmental impacts of hydrogen production vary significantly according to processes. In this paper, the different methods for producing hydrogen are studied in terms of their carbon emission loads, including steam methane reforming (SMR), gasification of coal, electrolysis, and new technologies, such as gasification of biomass and photoelectrochemical water splitting. SMR and coal gasification, producing gray and brown hydrogen respectively, presently dominate hydrogen production globally, causing major emissions of greenhouse gases. In contrast, blue hydrogen offers a reduced-carbon alternative from SMR with carbon capture and storage (CCS), while hydrogen produced by renewable energy via water electrolysis is considered the cleanest option. Carbon footprints are compared for different hydrogen production methods in this study, which also discusses technological innovations directed toward improving efficiency and reducing emissions. Particular emphasis is given to the scalability and economic viability of green hydrogen and innovative concepts, including high-temperature electrolysis, plasma gasification, and solar- driven hydrogen production. The paper also deliberates on the potential of policy incentives and pricing carbon emissions to facilitate rapid uptake of low-emission hydrogen. By weighing the alternatives between cost, efficiency, and environmental impacts, this paper reveals the most favorable sustainable hydrogen production pathways. The results substantiate the need for continued R&D, investments in infrastructure, and policy backing to allow hydrogen to deliver on the global decarbonization agenda.