Much hydrogen produced via water electrolysis (“green” hydrogen) requires downstream compression for end use or storage. A new electrolyzer concept developed by Supercritical Solutions Ltd. (London; www.supercritical.solutions) produces high-pressure hydrogen using a membraneless technology. “Supercritical’s technology outputs hydrogen at pressures up to 200 bar. These high pressures allow the system to reach much higher temperatures without evaporating the feed water into steam, which significantly increases the efficiency of the electrolysis reaction. Moreover, the hydrogen produced is already compressed for use or storage,” says Mike Russ, chief technology officer of Supercritical. Traditional electrolyzer systems cannot achieve such high pressures and temperatures because membrane integrity is compromised. “Our electrolysis takes place on our proprietary porous, flow-through electrodes. This unique design and morphology is not only more robust for high-pressure and high-temperature operation, but also simplifies the system by removing the need for complex membrane management,” explains Russ.
Source: Supercritical
Enabling operation at more extreme conditions than other electrolyzers significantly improves electrical efficiency, and the elimination of the membrane avoids the use of iridium and other scarce materials. “Regarding inputs, our technology operates with low-molar alkaline dissolved electrolytes to improve conductivity. We have conducted years of research and development to systematically determine which electrolyte is optimal for use at our unique operating pressures and temperatures ourselves, as minimal to no prior literature references exist,” adds Russ. The only byproduct of the system is high-pressure oxygen, which can be simply vented to atmosphere once its pressure is reduced.
The company has an advanced out-of-lab demonstrator in Teesside, U.K, which has been designed to test the system as a whole up to 6 kW, and the next step is to test the feasibility of scaling up this prototype unit with Shell Global Solutions International B.V. (The Hague, the Netherlands; www.shell.com), which entered a strategic collaboration with Supercritical Solutions in January 2026. For end users, such as fertilizer manufacturers, the access to inexpensive high-pressure hydrogen simplifies the process by eliminating the need for an ammonia syngas compressor. Additionally, says Russ, “the company is also exploring partnerships with e-fuel producers and refineries, and we can’t discount the benefits of producing at high pressure being ideal for storage and fuel-cell e-mobility.”
In February, Supercritical announced a partnership with platinum-group metals producer Valterra Platinum for a joint pre-feasibility study to determine how Supercritical’s membraneless electrolyzer technology can be used to provide on-site hydrogen refueling for fuel-cell electric vehicle (FCEV) taxis in Berlin.