Low pressure hydrogen storage: it is possible with new materials

The global increase in hydrogen capacity, particularly green hydrogen, has generated great enthusiasm. However, one of the main challenges to its widespread use is efficient storage.

Hydrogen can be stored as a gas or as a liquid. As a gas, it can be stored in high-pressure tanks and as a liquid at cryogenic temperatures to prevent it from being reduced to gas at about -252.8°C. It can also be stored in solid materials through an absorption process. Hydrogen storage for practical use presents several challenges. For example, transportation vehicles currently using hydrogen cannot hold the large amounts of compressed fuel needed to travel long distances. In addition, current storage solutions are very inefficient and lose large amounts of energy in the process.

The development of effective hydrogen storage solutions is critical to the advancement of hydrogen and fuel cell technologies in various applications. Hydrogen has the highest energy per mass of any fuel, but a high-tech storage solution is needed to ensure that the fuel or gas can be used effectively without losing excess energy.

In the United States, the Hydrogen and Fuel Cell Technologies Office (HFTO), supported by the Biden administration’s 2022 Inflation Reduction Act (IRA) funds, is conducting research and development to advance hydrogen storage system technology. To date, progress has been slow due to a wide range of challenges facing technology development, but now a California tech start-up appears to have the solution.

H2MOF is designing a tank that holds energy-rich fuel in a solid state by absorbing it into specially designed nanomaterials. The approach is based on research by two of its co-founders and scientific advisers: Omar Yaghi, professor of chemistry at the University of California, Berkeley, and Professor Sir Fraser Stoddart, winner of the 2016 Nobel Prize in Chemistry.

Metal-organic structure materials

The company hopes to be the first to commercialize metal-organic framework materials, or MOFs, designed at the atomic level for hydrogen storage, but it is not alone in pursuing this technology. Scientists at Lawrence Berkeley National Laboratory recently published research on an aluminum-based MOF they created to hold hydrogen, Science reported. This very material suggested the name to the companies

H2MOF is testing prototypes made from crystal-like materials designed to attract and hold hydrogen atoms like a sponge that absorbs water. And unlike the carbon-fiber-coated tanks used in Toyota’s Mirai fuel cell sedan, which hold hydrogen at a pressure of 700 kg/cm2, H2MOF intends to press its tank at less than a tenth of the previous one, thus not requiring tanks of any particular thickness, strength, or cost.

This type of storage can make hydrogen an energy source available almost as easily as fossil fuels, or at least as easily as the compressed methane normally used in cars. It would be a truly epoch-making innovation.

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