Membraneless electrolyzers for the production of low-cost, high-purity green hydrogen: A techno-economic analysis

Hydrogen is an ideal energy carrier that can facilitate the transition to a sustainable economy. However, hydrogen is generally produced through polluting and energy-intensive processes such as steam methane reforming and coal gasification. The benefit of steam methane reforming is that it is a well-established and inexpensive process with a production cost in the 1-2.4 USD/kg(H2) range. Hydrogen can also be generated through water electrolysis powered by renewables. This mode of production is costly with a levelized cost of hydrogen of 3-8 USD/kg(H2) due to the expensive membrane-electrode assemblies used in conventional electrolyzers. Membraneless electrolyzers remove these membrane-electrode assemblies altogether achieving separation of the generated gases fluid-mechanically. Despite the potential economic benefits of this technology, a techno-economic analysis of these devices is still missing; this article aims to bridge the gap in the literature. Several scenarios, including the source of electricity (renewables vs. grid), plant size, technological maturity, carbon tax level, and location are examined. Membraneless electrolyzers have a levelized cost of hydrogen of around 2 USD/kg(H2), rivaling steam reforming and showing far higher profitability than conventional electrolyzer technologies.