There has been great enthusiasm around the increase in global hydrogen capacity, particularly green hydrogen – which is produced using electrolysis powered by renewable energy sources, a process that does not emit carbon dioxide. However, one of the main challenges to hydrogen use is in the way it is stored. Hydrogen can be stored as a gas or liquid. As a gas, it can be stored in high-pressure tanks, and as a liquid in cryogenic temperatures to prevent it from boiling back into a gas – at around â252.8°C. It can also be stored in solid materials through a process of absorption. There are several challenges associated with hydrogen storage for practical use. For example, transport using hydrogen cannot currently hold the large quantity of compressed fuel required for travelling long distances. In addition, the current storage solutions are very inefficient, losing large amounts of energy in the process.
The development of effective hydrogen storage solutions is vital for the advancement of hydrogen and fuel cell technologies in applications. Hydrogen has the highest energy per mass of any fuel, but a high-tech storage solution is required to ensure the fuel or gas can be used effectively, without losing excess energy. In the U.S., the Hydrogen and Fuel Cell Technologies Office (HFTO), supported by funds from the Biden administration’s 2022 Inflation Reduction Act (IRA), is conducting research and development activities to advance hydrogen storage systems technology. To date, progress has been slow due to a wide range of challenges facing technological development.
A startup in California, founded in 2021 by two scientists believes it has discovered an innovative way to store hydrogen. The company, H2MOF, hopes to compress hydrogen into a small volume without the use of high pressure or low temperatures to store the fuel. If successful, the technology could be used to allow hydrogen to be stored at room temperature for a range of applications, including automobile fuelling. Many of the existing hydrogen storage methods are expensive and require high amounts of energy, making them inefficient. However, if hydrogen could be stored in a solid state it could massively reduce the storage burden.
Fraser Stoddart, winner of the Nobel Prize in Chemistry in 2016 and the co-founder of H2MOF, stated “The production of hydrogen, as far as I’m aware, is a settled problem.” He added, “There are ample efficient ways of producing hydrogen. The big challenge that remains is to store it in a manner that stores a lot of it at low pressures and ambient temperatures⦠“I am confident that one way or another we will get there of course.”
H2MOF believes that it can launch the innovative hydrogen storage technology within the next couple of years. The startup has been able to accelerate its research using AI and computer-generated models. The founders view hydrogen as key to achieving a green transition. Unlike electricity, hydrogen can be used as a fuel to power industrial operations, as well as for cooking and heating. It is also expected to be used as an alternative to electric batteries to power transport, particularly large vehicles such as ships and planes that cannot carry the heavy electric batteries needed to power them using electricity.
This is not the first time that scientists have offered an innovative solution for hydrogen storage. In 2023, a student group at Eindhoven University of Technology had the idea of using small iron balls (iron pellets) to carry hydrogen. The team developed a steam-iron process to achieve this. When iron is exposed to a flow of hot steam under high pressure it reacts with the water molecules, producing hydrogen and iron oxide, known as rust. Hydrogen can then be extracted to be used as an energy source. The remaining rust is regenerated back to iron with the addition of hydrogen, allowing iron to be a circular carrier of hydrogen. This is beneficial as iron has a higher energy density and can store approximately three times more energy per volume compared to pressurised hydrogen. The pellets can also be stored and transported much more easily, as they are safe and compact.
To date, many of the advances in hydrogen storage technology have emerged at the local rather than national level. Many startups and scientists believe they hold the key to unlocking hydrogen’s potential, but the question remains about whether they will be able to replicate and scale the technology to be used in large hydrogen operations. The U.S. is providing high levels of funding in hydrogen technology, with $9.5 billion of investment in the sector from the IRA and Bipartisan Infrastructure Law, which is expected to support accelerated research and development in the sector. The EU, MENA region and parts of Asia are also investing heavily in the development of hydrogen technologies to support the expansion of the world’s hydrogen capacity.
By Felicity Bradstock for Oilprice.com
