Exploring hydrogen storage solutions with Carbon280

Is hydrogen fuel the key to a clean energy future?

As we explore the potential for hydrogen as a promising renewable energy source, RSM has sought insights from industry experts at the forefront of pioneering solutions.

We recently had the pleasure of interviewing Mark Rheinlander – Founder and CEO of Carbon280. Mark and his team have developed a safe, scalable, and low-cost hydrogen storage solution called Hydrilyte®, which addresses many of the challenges currently hindering the broader commercialisation of hydrogen.  

To understand Mark’s view of these challenges, we asked him to share some of his insights…

Why the excitement about hydrogen fuel?

“Firstly, hydrogen has really high energy density,” says Mark. “1kg of hydrogen contains three times the energy of 1kg of diesel fuel. 

“Secondly, when you combust it, the waste product is water, not carbon dioxide (CO2). In contrast, when we use fossil fuels to power our cars, trucks and industry, we produce CO2. The CO2 escapes into the atmosphere, where it is very slow to break down and has now reached levels that are destabilising the global climate.” 

“When we use hydrogen as a fuel, it produces pure water instead of CO2. So, hydrogen is a molecule that allows us to store, transport and supply energy without damaging the planet.” 

Hydrogen is already used today as a precursor chemical in many industries, including petroleum refining, ammonia and methanol production, electronics, sugar processing, and more. Its energy density makes it an alternative for energy supply and storage when the economics of poles, wires and batteries don’t make sense. Hydrogen enables us to store energy indefinitely without losses over time.

With the right storage technologies, hydrogen enables us to move energy safely and in large volumes from places with excess energy to places with an energy deficit.

What is the general perception of hydrogen?

“Hydrogen has a mixed reputation, and often one of the first images that comes into people’s minds is the Hindenburg airship disaster in 1937,” says Mark.

“But why did the Zeppelin Airline Company choose hydrogen as the buoyancy gas for their airship in the first place? As the first element on the periodic table and being made up of a single proton and electron, hydrogen is the lightest of all elements. This makes it much lighter than air and, at first sight, an excellent gas to fill a balloon with as it floats so well. “

This also explains why, despite being the most common element in the universe, there is so little hydrogen gas on Earth. Any hydrogen gas released by biological and geological processes disappears into space unless it is trapped like natural gas. 

As well as being a very light element, hydrogen is also very flammable. It has a flammability range considerably wider than other fuels and has a minimum ignition energy of less than a tenth of natural gas. 

“Even a spark from static electricity is enough to ignite it. It is this second characteristic that made hydrogen a poor choice for a people-carrying balloon.”

Can we store hydrogen?

“Storing hydrogen safely is challenging because you have to deal with both of these characteristics – its lightness and its flammability,” says Mark.

“Hydrogen is very light. As a general comparison: 1kg of diesel has a volume of around 1.25 litres, 1kg of natural gas has a volume of 1.5m3, and 1kg of hydrogen gas has a monstrous volume of 11m3! So, we can see that while hydrogen is very energy dense by weight, it is very energy poor by volume. And as we have seen, it is also very flammable. This is why developing new technologies that enable us to store and transport hydrogen safely is one of the biggest challenges for the energy transition.”

Physical storage options for hydrogen

Mark outlines that there are broadly two approaches to storing and transporting hydrogen: physical storage and chemical storage.
Physical storage uses technologies similar to those used with gases like methane. Variously, combinations of compression, liquefaction (cooling a gas until it becomes a liquid) and specialised sponge-like materials that can confine gases, can be used to increase the density of the hydrogen gas. The physical carriers all have the ability to release hydrogen rapidly, which is critical for hydrogen mobility applications.

Compressed Gas

“The simplest approach is to compress the hydrogen gas. However, being so light an element means a lot of compression is required. The pressures are very high – 10,000psi compared to your car tyres at 40psi – and much higher than those for other industrial gases. This means compression costs are high.” 

Compressed hydrogen storage uses high-pressure tanks to contain hydrogen gas, which is essential for its practical application. To store hydrogen effectively, it must be compressed at high pressures ranging from 350 to 700 bar (5000 to 10,000 psi). These gas tanks are specially designed to withstand such high pressures, making them robust yet costly. 

The energy density of hydrogen by weight is impressive, but its low volumetric energy density means that a significant volume is required to store even small amounts of energy. Therefore, the design and engineering of these gas tanks are crucial to ensure safety and efficiency in hydrogen gas storage. 

“The cylinders that store the hydrogen are expensive because they must withstand those pressures. The transport costs are high because the specialised trucks that carry compressed hydrogen are also very expensive, at about 5 to 10 times the cost of a diesel truck.”

Despite the challenges, compressed hydrogen storage is a well-established method that forms the backbone of the current hydrogen supply chain.

Cryogenic Liquid Storage 

Another physical storage approach is to liquefy the hydrogen, which has been used by NASA since the 1950s. Cryogenic liquid storage involves cooling hydrogen to cryogenic temperatures of around -253°C to convert it into a liquid state. This method increases hydrogen's energy density, allowing for a more compact storage solution than gaseous hydrogen. 

Says Mark, “Cooling anything down to that temperature takes a lot of energy, and more energy is required to keep it that cold. If the temperature rises above -253C, the hydrogen ‘boils off’ and is lost.”

Specialised insulated tanks are necessary to minimise this evaporation, adding to the complexity and cost of this storage method. 

“Despite all the energy that goes into cooling hydrogen and keeping it liquified, though, 1M3 of liquid hydrogen only weighs around 71kg. For comparison, 1m3 of water weighs 1000kg.”

Nevertheless, liquid hydrogen has been successfully used in various applications, including space travel and high-purity industrial processes. Its high energy density makes it a viable option for industries that require large amounts of hydrogen in a compact form.

Metal Organic Frameworks

“More recently, some clever new materials have been developed – Metal Organic Frameworks (MOFs) – which are like metal sponges with atom-sized pores. They can be custom-designed for different gases. Hydrogen MOFs trap hydrogen and require only moderate cooling and compression to reach densities close to liquid hydrogen. This makes them potentially more cost-effective than physical carriers. 

“The Australian company Rux Energy is an exciting leader in this space. MOFs, like compressed and liquid hydrogen, can release hydrogen quickly which is a critical requirement for on-board hydrogen applications (planes, trains, trucks and cars) and for buffering services with high demand variability. Due to their low pressures and more moderate temperatures, MOFs can also be safer than the compressed and liquid variants.”

Chemical storage options for hydrogen

“Chemical storage of hydrogen utilises the fact that hydrogen bonds readily to other elements to make very familiar substances,” says Mark. “Water is a compound of hydrogen and oxygen. Sugar, bread, and alcohol are compounds of carbon, hydrogen, and oxygen.

“Chemical carriers include ammonia, liquid organic hydrogen carriers, and metal hydrides. These are better alternatives for storing and transporting hydrogen in large volumes because they are significantly more cost-effective at large scale.

Ammonia-based hydrogen storage

“Ammonia is a compound of nitrogen and hydrogen, and 1m3 of ammonia contains around 107kg of hydrogen. Counterintuitively, that’s considerably more than liquid hydrogen at 71kg per m3. This highlights the advantage of chemical storage, that often the densities are close to or greater than liquid hydrogen and require little or no energy for compression or cooling. 

“Ammonia production is an advanced industry, and millions of tonnes of it are safely transported around the world today.  This has led to huge interest in ammonia as a hydrogen carrier. However, the chemical bond between nitrogen and hydrogen is very strong and ‘cracking it’ to release the hydrogen requires a lot of energy. Ammonia cracking also requires specialist platinum group catalysts that are expensive and supply-chain-constrained. And while the ammonia production process is mature, the cracking technology is not. Most projects making the news in Australia are for the production, transport, and delivery of green ammonia – not of hydrogen. 

“Ammonia toxicity is the biggest issue preventing full commercialisation. Large-scale ammonia spills result in deaths, severe burns, and lung damage. Ammonia is also highly toxic in the marine environment, but more studies are required to quantify that danger. It can be managed safely, but expensive infrastructure, highly trained personnel, and costly maintenance across the entire supply chain are required to ensure that it stays safe. While making ammonia safe to handle is achievable in the chemical supply chain, where suppliers and users are typically sophisticated companies with safe premises, this will be extremely hard to ensure in the energy supply chain, which has many more transition points where there is potential for interaction with unskilled labour and the public.

Liquid organic hydrogen carriers

“Liquid organic hydrogen carriers (LOHCs) are organic compounds that react with hydrogen to form a ‘hydrogenated’ variant of the compound. The process of storing hydrogen in LOHCs involves binding hydrogen to the carrier molecule in a reversible way. Hydrogenation and dehydrogenation can be controlled by varying the temperature and pressure conditions. 

“The LOHC is a liquid and can then be stored and transported using the existing liquid fuels infrastructure. Hydrogen is added via the hydrogenation reaction, which is exothermic, meaning it is self-sustaining. Hydrogen is released by heating the LOHC in a dehydrogenation reaction, which requires energy input. LOHCs have moderate to severe toxicity, depending on the specific LOHC, but are significantly less toxic than ammonia. 

“Like ammonia, LOHCs require expensive catalysts to facilitate absorption of hydrogen. Another issue is that dehydrogenation (releasing the hydrogen) involves ‘cracking’ the LOHC. The cracking process is not perfect and results in some hydrocarbons being carried through with the hydrogen. This means that additional purification systems are required for applications that require very pure hydrogen, such as fuel cells that generate electrical power from hydrogen. This process decreases the overall cost efficiency. Cracking also leads to product stability issues that reduce product lifetime if not controlled. 

Materials-based hydrogen storage 

“Another chemical solution is metal hydrides, which occur when some metals react with hydrogen. Hydrides store hydrogen within a range of temperature and pressure conditions and will release the hydrogen again outside of those. Heat and pressure can be used to control the loading and unloading of these metals with hydrogen. Examples of metals are lithium and magnesium. 

“Hydrides provide good hydrogen storage density, and the energy required to store and release hydrogen is competitive with ammonia and LOHCs. Magnesium has been researched as a hydrogen storage material since the 1950s, and it can store 111kg of hydrogen per cubic metre. One of the challenges with hydrides is that they are reactive, not just with hydrogen but also with oxygen and water. Many hydride solutions require moderate pressure and/or cooling and containment to use them safely.”

How is Carbon280 addressing these challenges?

“Carbon280 is based in Perth, and we have set ourselves the challenge of developing a hydrogen storage material that is economically viable, safe for people to handle, and non-toxic to the environment,” explains Mark.

“This has resulted in a new hydrogen storage technology called Hydrilyte®: a metal hydride powder suspended in mineral oil. The mineral oil insulates the otherwise reactive metal powder from the air and transforms it into a material that can be safely handled without protection. It is also non-toxic to people, animals, and marine life in the event of a spill. 

“Hydrilyte® has a high storage density and low round trip energy costs. The hydriding and dehydriding reactions are fully reversible, and we don’t need to crack anything, so the product is very stable. Unusually for an energy storage material, we don’t see noticeable degradation in our lab testing. Performance continues to improve the more it is cycled. 

“Being a liquid, Hydrilyte® can be pumped, which means that, similar to the LOHCs, the existing liquid fuels infrastructure (ships, trucks, and pipelines) used to store and transport oil and diesel can be used to move hydrogen. 

“We’re currently building a pilot plant in Kwinana to demonstrate the Hydrilyte® technology using $10m of seed funding we have received from Woodside Energy and UK renewable developer Hive Energy. Hydrilyte® has applications in hydrogen-based steel making, hydrogen for the chemicals industry, hydrogen transport, export and distribution, and long-duration energy storage, providing a clean alternative to natural gas for smoothing solar and wind intermittency.”

Watch this space

With the clean energy landscape continuing to evolve, RSM is keeping our finger firmly on the pulse. We are excited to see new innovations develop and to work with our clients to help position them for success across our business advisory, audit, risk management, ESG, cyber and consulting teams. 

To start a conversation with one of our experienced advisers, contact Dan Hutchens in Perth on (08) 9261 9302, Jacob Elkhishin in Brisbane on (07) 3225 7819, or your local RSM office.