Project UNICORN seeks to develop PEM electrolyzer with increased performance, reduced CAPEX, and increased sustainability
A €2.94-million project coordinated by SINTEF seeks to develop and demonstrate a proton exchange membrane (PEM) electrolyzer stack with increased performance, reduced CAPEX, and increased sustainability compared to current PEM electrolyszer systems.
Participating with SINTEF in the UNICORN (“Unlocking the Full Potential of Electrolysis with Next-Generation Proton Exchange Membrane Stacks”) are Hystar (industry partner, Norway), Alleima (industry partner, Sweden), Research Institutes of Sweden (RISE) (research organization, Sweden), Ionomr Innovations Inc. (industry partner, Canada), The French Corrosion Institute (research organization, France), University of Montpellier/CNRS (academic institute, France).
In the PEMWE (PEM Water Electrolysis) process, water is converted into oxygen gas and protons on the anode side of the membrane. These protons move across the membrane to the cathode side where they react with electrons to produce hydrogen gas. This hydrogen can then be transported in pipelines, stored in tanks, and used in industry or transport. Figure: SINTEF
In this project, a 40 kW stack that contains novel, beyond state-of-the-art components will be built and tested during 2000 hours of operation.
The project aims to replace expensive platinum group metal (PGM)-coated titanium bipolar plates (BPPs) with low-cost coated stainless steel; reduce the amount of iridium used in the catalyst layer to half of the current commercial standard; and eliminate the use of hazardous fluorinated compounds, specifically perfluorosulfonic acid (PFSA)-based materials, in the membrane and catalyst layers.
The innovations will be tested initially on a lab-scale before upscaling with the help of the project’s industrial partners.
The project is set to begin 1 November 2023 and will run for three years.
Background. There are two main types of electrolysis in use today: alkaline, and PEM (Proton Exchange Membrane). Compared to traditional alkaline electrolysis, PEM electrolyzers have higher performance, and can respond to quick changes in power supply, making them suited for coupling with renewable energy sources, according to SINTEF.
However, the major shortcoming of PEMWE is that it needs expensive and rare materials to overcome the harsh operating environment while producing high quality gases in a safe way.
Today’s commercial PEMWE systems all rely on materials that lead to a high cost of the electrolyzer and have been identified as critical raw materials, or materials with sustainability/environmental concerns. These materials are noble metal catalysts and protective coatings, titanium-based bipolar plates, and perfluorinated sulfonic acid (PFSA)-based membranes.
In the project’s electrolyzer stacks, the critical raw material titanium is replaced with stainless steel, and the iridium loading is decreased by 50%. In addition, replacing fluorinated membranes will improve the sustainability, providing more environmental friendly hydrogen production, at a significantly reduced cost.