The McPhy solution
Metal hydrides
Metal hydrides are chemical compounds formed when hydrogen gas reacts with certain metals.
McPhy has selected magnesium hydrides (MgH2) for mass storage because they offer a large range of benefits.
- Totally reversible storage: Mg + H2 ↔ MgH2
- Loading at typical electrolyser outlet pressure (10 bar)
- Unloading at fuel cell/H2 gas turbine inlet pressure (2 bar)
- No compression (energy, cost and maintenance savings)
- High cycling stability
For a given temperature, if the pressure is above a certain level (the equilibrium pressure), the metal absorbs hydrogen to form a metal hydride. If the pressure is below the equilibrium pressure, hydrogen is desorbed, and the metal returns to its original state. The equilibrium pressure varies directly with temperature.
Efficiency
Metal hydrides provide a much higher volume density than compressed or liquid gas.
No compression is required during the loading/unloading process. With a 97% efficiency rate, McPhy’s products allow significant energy, cost and maintenance savings compared to existing gas storage solutions for which 10 to 25% of gas energy content is used for compression.
Safety
Hydrogen is an extremely light and inflammable gas and safety requirements implemented by countries have been strong. Pressurized and liquefied hydrogen storage infrastructures are less and less welcome in urban environment, which further pushes in favor of alternative storage technologies.
In the case of large quantities, pressurization and liquefaction technologies appear as both inefficient and unreasonable from a safety perspective whereas McPhy’s products allow a drastic reduction of risks.
Logistics
Existing storage technologies that need to be delivered suffer from a structural risk related to potential logistical problems such as strikes or accidents. In addition, trucks accessing to industrial areas through cities and villages need to comply with various limitations that make transportation an important issue. McPhy’s independent on-site storage is thus a strong advantage.
Ease of use
McPhy’s products are ‘plug and play’ and do not require the presence of operators or expensive maintenance. Thanks to a modular approach in standardized size, they are easy to transport.
Carbon footprint
Thanks to McPhy’s patented technology, the heat that is released from the absorption reaction can be recuperated for the desorption reaction. In this case, the energy necessary to store hydrogen is very low compared to direct storage solutions. This reduced energy necessity not only translates in a lower cost, but also in a lower carbon footprint through the lifetime of using McPhy’s solid-state hydrogen storage solution.
Other advantages
Magnesium is an abundant and affordable material without any environmental impact. In addition, because of its non-reactivity with other materials, the magnesium hydrides do not have to be stored in containers made from specially treated metals.