Perspectives on CO2-Free Hydrogen Production: Insights and Strategic Approaches

Hydrogen is a necessary element in the transition to sustainable energy systems and plays a crucial role in achieving net zero emission targets. However, the current methods of hydrogen production are characterized by high carbon emission intensities. For instance, the production of hydrogen is responsible for approximately 1.05 billion tons of CO2 annually. This equates to about 11 kg of CO2 emitted per kg of hydrogen produced, significantly higher than many other industrial processes like ammonia, iron and steel, methanol, ethylene, and cement production. To address the urgent need to meet global decarbonization goals, it is crucial to develop and scale up low-carbon hydrogen production technologies, especially given the significant carbon emissions currently associated with existing methods. This review investigates to strategies for decarbonizing the steam methane reforming (SMR) process, exploring multiple pathways to significantly reduce its carbon footprint. These approaches include SMR with carbon capture and storage, SMR with electrolyzer, standalone electrolyzer, electrification of SMR (e-SMR), and improving energy efficiency within existing SMR infrastructures. Additionally, alternative methods such as dry methane reforming and methane pyrolysis are emerging techniques that utilize natural gas to produce low-carbon hydrogen, offering reductions in carbon emissions compared to traditional SMR. This study presents a comprehensive analysis of low-carbon hydrogen production, offering valuable insights into the pathways for achieving this goal. It identifies the key opportunities and challenges in commercializing these technologies and provides strategic recommendations to enhance their feasibility and market adoption, which are enhanced by ongoing research and development efforts. Achieving low-carbon hydrogen production can be realized through the integration of carbon capture and utilization and the use of low- or high-temperature electrolyzers, which significantly reduce the overall carbon footprint per unit of hydrogen in the short term. In the medium to long term, low-carbon hydrogen can be produced effectively via water electrolysis or e-SMR. The strategic integration of these technologies offers a sustainable pathway for hydrogen production, aligning with environmental and economic goals.