Shell has signed a collaboration agreement with UK-based start-up Supercritical Solutions to advance a novel membrane-less low-temperature electrolyser technology towards a pilot demonstration project.

Technology and Efficiency

The core of the collaboration is Supercritical's electrolyser, which requires only 42 kilowatt-hours of energy to produce one kilogram of hydrogen. This represents a significant efficiency breakthrough for low-temperature electrolysers, where 50 kWh/kg is considered highly efficient. Only two other start-ups, Hysata and Cipher Neutron, have promised slightly higher efficiencies for their respective technologies. Commercially available high-temperature solid-oxide electrolysers can achieve higher efficiency but require the addition of waste heat to do so.

Technical Advantages and Design

Supercritical's patented system operates at elevated pressure and temperature, aiming for high system efficiency and delivery pressures up to 220 bar without the need for separate hydrogen compressors. This design eliminates dependency on rare-earth materials or membranes that can degrade or pose supply risks. The ultimate goal is to lower the cost of renewable hydrogen to accelerate its adoption as a feedstock and for use in hard-to-electrify sectors.

The technology differs from conventional designs by using solid, porous structures that act as both electrodes and cell walls. Water or steam flows through these layers, where electrolysis occurs. The tiny pores precisely control the movement of liquids and gases, preventing hydrogen and oxygen from mixing while allowing them to be collected at high pressure. The manufacturing method for these porous electrodes is also patented.

Collaboration and Commercialization

Shell, which is an investor in Supercritical having contributed to its 2024 Series A funding round, is planning to build the pilot project itself. The agreement involves a technology feasibility study to support the evaluation and planning of the pilot demonstration. For Supercritical Solutions, this collaboration is seen as a major milestone on its commercialization journey.