Through its Shell GameChanger Accelerator program, the oil company is trying to encourage young companies working on solutions that will allow us to move around in a greener way. In the last 3 startups hosted, 2 are following tracks concerning green hydrogen: Ionomr Innovations and Versogen.
For mobility and small stationary applications, proton exchange fuel cells are mostly used. Inside, hydrogen is oxidized at the anode where electrons are separated from protons on the surface of a rare metal catalyst. These protons pass through a PEMF membrane. At the same time, electrons move in a peripheral circuit, creating the current. On the cathode side, another catalyst made of a critical material combines protons and electrons with oxygen from the air to produce water at the exit of the cell. The use of rare metals has a heavy impact on the manufacturing cost of PACs, but also on the environmental impact.
Pemion membranes in a PEMF cell
Ionomr Innovations has developed two families of membranes that can be used in electrolyzers and hydrogen fuel cells. For the latter, the Vancouver, British Columbia-based start-up proposes to replace conventional PEMF membranes.
Its Pemion technology has superior chemical stability and a longer life span. The use of Ionomr Innovations’ hydrocarbon membranes also increases the durability of cell electrodes. This is due to the fact that the need for rare metals in the catalysts is now very low. PACs equipped with Pemion technology are able to operate at higher temperatures, with a conductivity that is double the industry standard. All these points contribute to obtaining batteries with improved performance for a longer life, a better environmental impact, and a lower production cost.
2 types of electrolyzers
In order to show the contribution of its membranes, Ionomr Innovation recalls on its website the 2 main electrolysis processes: alkaline or polymer electrolyte membrane (PEM) electrolysis. Both processes use electric current to split water molecules into hydrogen and oxygen. The former uses potassium hydroxide (KOH) as a liquid electrolyte to transport the anions (OH-). A porous diaphragm separates the cell into two.
The advantage of this process is that it uses only nickel and iron as catalysts and allows the use of stainless steel in the plant. However, it is not suitable for the production of green hydrogen for sustainable mobility. On the one hand because of the residual impurities in the H2 gas, and on the other hand because of its poor compatibility with intermittent energy sources at the input of the electrolyzer. This is why, despite the expensive materials used (platinum and iridium for the catalysts, titanium for the installation), PEM electrolysis is preferred to produce hydrogen to be used in fuel cells for low carbon mobility. Here, a solid polymer electrolyte is used. With a higher final yield, it selectively carries protons for water splitting reactions.
Pemion membranes also for electrolyzers
In PEM electrolyzers, Pemion membranes can be used with the same benefits as in PEMF cells. These include doubled conductivity, higher maximum operating temperatures, significantly longer service life, reduced critical metals in the catalysts, and ultimately lower investment in plant design.
For fuel cells and alkaline electrolyzers, Ionomr Innovation has also developed alternative AEM (anion exchange membranes), called “Aemion”. Particularly stable and durable, they are reserved for uses other than the production of green hydrogen from renewable and intermittent energy sources. They do, however, reduce the environmental impact of grey H2 production.
Between 2 worlds
Now that we are convinced that alkaline electrolyzers are not compatible with green hydrogen for mobility, let Versogen convince us otherwise! Located in Wilmington, Delaware, this other Shell GameChanger Accelerator startup has decided to tackle the electrolyzers themselves to benefit from the advantages of both alkaline and PEM processes. These installations, described as “revolutionary” by the startup, use AEM membranes.