Low-Carbon Hydrogen Production via Ethanol Reforming Reactions in Membrane Reactors: Recent Advances and Future Directions

The emission of greenhouse gases (GHGs) has escalated to unprecedented levels due to the extensive use of fossil fuels for industrial development and population growth. Consequently, the transition to clean and renewable energy sources is critical for mitigating climate change. Hydrogen is considered a promising energy carrier that can be produced from both conventional (fossil fuels) and renewable resources (biofuels and water). Among renewable sources, ethanol is favored over other bioalcohols because it has a high energy content and is less toxic than hydrocarbon fuels. In addition, ethanol reforming represents a viable method of efficiently producing renewable hydrogen. To enhance this process, innovative technologies have been developed, particularly through the use of a membrane reactor (MR) technology. In MRs, the reaction and separation processes occur simultaneously, which improves the selectivity and yield while reducing operating conditions and preventing coke formation. This study aims to highlight recent advancements in ethanol reforming reactions─including steam reforming, partial oxidation, and autothermal reforming reactions─to produce renewable, low-carbon hydrogen using MR technology. In particular, the central focus is to provide a comprehensive analysis of the performance of different MRs, shedding light on their efficacy, scalability, and potential limitations in the context of renewable hydrogen production from ethanol reforming. By exploring these aspects, this study attempts to inform strategic decisions and advancements in sustainable energy technologies, facilitating the transition toward a greener, more resilient energy landscape.