Advancements in Electrochemical Hydrogen Compression

M. Hamdan
Giner ELX, Inc.,
United States

Keywords: fuel cell, hydrogen


Recent developments in membrane technology promise a new generation of very efficient low-cost electrochemical-hydrogen-compressors (EHCs). In the EHC process, low-pressure hydrogen (H2) is fed to the anode of an acidic electrolyte cell, where H2 gas is oxidized to form protons (H+) and electrons. The protons are ionically transported across the electrolyte, in this case a polymer electrolyte membrane (PEM), to the cathode, where H+ ions are reduced, forming H2 at higher pressure. Electrons move from the anode to the cathode through an external circuit. The PEM requires water to transport H+ (electro-osmotically). A significant innovation within Giner ELX’s EHC concept is the integration of a proprietary water management membrane that works in unison with the PEM to finely control the amount of water it experiences. EHCs have the potential to achieve higher reliability and efficiencies compared to conventional mechanical compressors. Giner ELX’s work on EHCs exploits the use of novel technologies that include the use of water management membranes in addition to PEM membranes engineered with low electro-osmatic drag and low hydrogen diffusivity, and an advanced high-pressure stack design optimized for safe high-pressure gas compression and low resistive losses. The successful development and implementation of these technologies have been key to improving efficiency, reducing cell-voltage required for 350-bar compressors by >50% compared to state-of-the-art, improving water and thermal management within the EHC, and enabling high current density operation resulting in a low-cost hydrogen compressor. The presentation will start with a short introduction of Giner ELX’s commercial MW Electrolyzer technology for renewable energy applications followed by an in-depth review of the advancements made in PEM-based EHCs.