Hydrogen is a promising alternative fuel for vehicles, as it can produce zero-emission electricity through fuel cells. However, storing enough hydrogen on board to achieve a reasonable driving range is a major challenge. In this article, you will learn about some of the ways that hydrogen storage can be optimized for fuel cell vehicles, and the trade-offs involved.
One of the most common methods of storing hydrogen is to compress it at high pressures and store it in cylindrical tanks. This allows for a relatively simple and fast refueling process, and a high volumetric energy density. However, compressed hydrogen tanks also have some drawbacks, such as the need for heavy and expensive materials to withstand the pressure, the risk of leakage or rupture, and the limited space available for tank placement in the vehicle.
Die gr??te Herausforderung für einen Druckwasserstofftank ist die Kombination aus Sicherheit, Dichtigkeit und Haltbarkeit, wobei der Fokus der Weiterentwicklung bisher immer auf der reinen Gewichtsreduktion lag. Aktuell findet der Sprung vom Typ4 (Liner aus Kunststoff) zu Typ5 statt, bei dem ohne Liner vollst?ndig auf Verbundstoffe gesetzt wird. Meine Prognose: Bei Typ 6 wird nicht mehr die reine Gewichtsreduktion im Mittelpunkt stehen, sondern die Integration einer intelligenten Steuerung und überwachung um die Peripherie zu entschlacken.
Although compressed hydrogen tanks are an efficient storage option, they come with some challenges. The high-pressure requirements necessitate thick and heavy tanks, made from expensive materials, which can add to vehicle weight and cost. Additionally, the risk of leaks or ruptures calls for stringent safety measures and ongoing maintenance, which can add complexity. Moreover, finding enough space for bulky tanks, especially in smaller vehicles, is a design limitation. These limitations require continued research to develop lighter, safer, and more compact compressed hydrogen storage solutions, which will pave the way for wider hydrogen fuel cell technology adoption.
Mejoras en los materiales utilizados. Fuertes regulaciones en materia de seguridad y fabricación de dichos tanques. Uso de celdas de combustible que puedan realizar reformado directo o indirecto de manera que no se almacene hidrógeno Uso de hidrógeno líquido a bajas presiones y muy muy bajas temperaturas
Given the required mid-stream assets (e.g., pipeline connectors, delivery trucks/trailers, local electrolyzers, storage tanks, cooling/heating equipment, compressors, fuelling pumps) to deliver hydrogen at the fuelling point, pressurized H2 is the current low-cost alternative from a systemic point of view.
Currently.the high pressure (~700 bars) hydrogen tanks are the feasible option in term of the high specific storage capacity (6-7 wt%) with the lower storage density that takes quite bit onboard space. The metal hydride hydrogen storage tanks have lower specific storage capacity (~1 wt%), but high storage density that fit stationary storage or heavy engineering vehicles such as forklifts and mining vehicles.
Another option is to liquefy hydrogen at very low temperatures and store it in cryogenic tanks. This can increase the mass energy density of hydrogen, and reduce the tank weight and size. However, liquid hydrogen tanks also have some challenges, such as the high energy and cost required for liquefaction, the boil-off losses during storage and transport, and the complex and slow refueling process.
In addition, one of the benefits of using liquid hydrogen is that it is ideal for transporting hydrogen in tankers and consumed immediately. This is because liquid hydrogen has a low boiling point and as a result, it can easily boil off and escape during storage and transport. However, if consumed immediately, there will be no loss of product due to boil-off. Therefore, it is best to produce liquid hydrogen only when it is required, rather than storing it for prolonged periods.
Liquifying hydrogen offers a very dense and space-efficient way to store hydrogen, Insulated dewars can only keep hydrogen cold enough for so long, before it boils and evaporates away. So, liquid hydrogen stroage can be ideal if the rate of consumption is steady and predicatable.
In my experience liquid hydrogen tanks are well suited for high flow and high pressure applications. For high flow applications, having enough gas on site is not feasible. For high pressure applications, cryogenic liquid compression is much easier than gas compression. Less parts means less failures. For transportation, liquid hydrogen tankers are more efficient than gas trailers. If you look to the industrial gas majors, they move it mostly in liquid form. There is technology coming that will eliminate boil off on fixed ground stationery tanks and zero loss during transfers. The technology is like what we see in current liquefied CO2 tanks.
This option I think is not so much practical at least for light-duty transport. Boil-off is one problem, the cost of fuel supply is another (vacuum-jacketed lines). Now imagine there is a collision and your liquid hydrogen storage system lost its vacuum as a result! Disaster disaster!
Here, the high cost of conversion processes is a big issue. Many lovers of EVs in places like Africa ain't been able to buy them up till now.
A third possibility is to store hydrogen in metal hydrides, which are compounds that can absorb and release hydrogen through chemical reactions. Metal hydrides can offer a safe and compact way of storing hydrogen, without the need for high pressures or low temperatures. However, metal hydride storage also has some limitations, such as the low gravimetric energy density, the high cost and weight of the materials, and the slow kinetics and heat management of the reactions.
While the text accurately describes metal hydride storage's potential for safe and compact hydrogen storage, it's crucial to acknowledge additional complexities. One promising approach involves customising the composition and structure of metal hydrides to maximise hydrogen capacity and release rates. This could involve engineering alloys with enhanced hydrogen uptake, exploring new classes of complex hydrides with higher densities, or designing nano-structured materials for faster kinetics. Addressing cost and weight remains challenging, but promising avenues include exploring lighter metals like lithium and magnesium and developing efficient recycling processes for spent materials.
The metal hydride storage has a congenital thermodynamic obstacle. To store more hydrogen atoms in metal lattice needs higher bonding energy to form high capacity metal hydrides. To release the stored hydrogen from these high capacity metal hydrides, you need higher temperature. For example, MgH2 stores 7.3wt% hydrogen, but it need 300C to desorb hydrogen. DOE forms three Hydrogen Storage Materials Research Centers, there is no single material that meets all requirements of on-board storage after 5 year extensive research. Obviously, the nature law does not help.
H2 is a tiny molecule, and can thus be stored within the structures of solid materials. Metal hydride storage can work synergistically with more traditional hydrogen storage solutions (e.g., compressed gas, liquefied), to realize system-wide advantages.
I do wonder who comes up with these LinkedIn advice articles...this just another example of a technology looking for a justification. As other commenters have said, the energy density is poor and you need high temperatures to release the explosive gas from the hydride. Not exactly a recipe for safety.
Besides the three methods mentioned above, there are also other emerging technologies that aim to improve hydrogen storage for fuel cell vehicles. Some examples are carbon nanotubes, metal-organic frameworks, ammonia, and organic hydrides. These technologies have the potential to overcome some of the drawbacks of the existing methods, and offer higher energy densities, lower costs, or easier handling. However, they also face some technical and practical challenges, such as scalability, durability, safety, or compatibility with fuel cells.
Alongside the innovative methods mentioned, methanol is another promising option in the hydrogen storage arena. Unlike gaseous hydrogen, methanol is a liquid at room temperature and pressure, making it readily transportable and compatible with existing infrastructure like pipelines and tankers. Methanol can also be produced using renewable sources like biomass or captured carbon dioxide, potentially paving the way for a carbon-neutral fuel cycle. Ongoing research in catalyst development and direct methanol fuel cells aims to unlock the full potential of this versatile hydrogen carrier.
The process of making ammonia requires hydrogen. That hydrogen usually comes from steam-methane reforming. Co-locating ammonia produce with steam-methane reforming plants keeps production costs low, but results in a level of carbon dioxide emissions. To mitigate climate impacts, the carbon dioxide can be captured and sequestred or used in some cases.
For me, the use of metal hydrides to store hydrogen shows great promise because substances like Ti, Li, Al, etc, aren't new in manufacturing. With the availability of ores of these hydrides in nature plus continuing R & D, known barriers to hydrogen storage in fuel cells can be surmounted in no distant future.
Keeping in mind that any novel vehicle on-board storage requires a matching H2/derivative delivery system with the right on-site storage volumes, temperature, pressure and flow rate parameters, emerging technologies will likely need to be able to use 350-700bar or liquefied H2 outlets as sources.
The only sensible and relatively high density method mentioned here is ammonia. Aramco used this to transport hydrogen not so long back. Ammonia has the advantage of being movable by ship, pipeline or train and is cheap. Hydrides are a non-starter.
To optimize hydrogen storage for fuel cell vehicles, there is no one-size-fits-all solution. Instead, different methods may suit different applications, depending on the vehicle type, size, performance, and usage. Consequently, some of the optimization strategies that can be adopted include choosing the appropriate storage method based on the specific requirements and constraints of the vehicle, combining different storage methods to achieve a balance between energy density, cost, safety, and convenience, developing novel materials and processes that can enhance the efficiency and reliability of hydrogen storage, integrating hydrogen storage with other components of the vehicle such as the fuel cell or battery, and adopting smart control and management systems that can monitor and regulate the hydrogen storage conditions and performance.
Optimising hydrogen storage involves considering several factors, not just technical ones. To achieve high energy density, cost or complexity may need to be compromised, while prioritising convenience may affect the range. Therefore, it is important to understand the operational needs and user preferences of a vehicle to tailor the storage solution for an optimised experience. By adopting a human-centred approach, the full potential of hydrogen technology can be unlocked by aligning its technical capabilities with real-world usage patterns.
I would like to comment a strategy to refuel safety & with less consumption of energy, especially for 700 bar. To refuel at 700 bar we must store at 900 bar which implies greater energy consumption. For this reason, CASCADE refueling is designed, dividing the buffer volume into multiple tanks with various pressure levels. The lowest pressure level is used at the beginning of refueling before automatically switching to intermediate pressure levels and only the highest-pressure level of 900 bar is used at the end. It seems that at least with these 3 stages of pressure, we would save energy, & the refueling would be more safety, in terms of temperature.
The pipeline network for natural gas in North America not only serves to mobilize and transport the commodity, but also represents a massive storage solution. Consider a similar network for piping hydrogen throughout markets ... the pipeline would also serve as a storage reservoir. The storability of hydrogen is a crucial characteristic supporting its role in decarbonizing the global economy.
The fuel loading station for H2 will require a refrigeration cycle of propane, at least. A propane cascade refrigeration cycle will lower the temperature to -127 °C, and energy requirements are intensive. Other options for cryogenic cycles are available, but H2 fuel station process conditions must be set in order to choose a lower-energy cascade refrigeration cycle.
Hydrogen storage is a key factor that affects the feasibility and attractiveness of fuel cell vehicles. By optimizing hydrogen storage, fuel cell vehicles can achieve higher driving ranges, lower emissions, and better customer satisfaction. However, there is still room for improvement and innovation in hydrogen storage technologies, and more research and development is needed to overcome the existing challenges and barriers. As the demand and support for clean and sustainable mobility grows, hydrogen storage can play a vital role in the transition to a hydrogen economy.
Optimising hydrogen storage in fuel cell vehicles can offer more benefits than just extending the driving range. Lighter tanks can improve efficiency, while modular designs can enable fueling flexibility. Chemical storage alternatives hold promise for increased density and easier integration, and they can even make onboard hydrogen generation. Moreover, hydrogen carrier materials and infrastructure advancements could simplify distribution and refuelling, providing a unique user experience. Furthermore, by addressing safety concerns and public perception, alongside technological improvements, hydrogen storage can truly become the catalyst for a widespread shift towards a clean and sustainable hydrogen economy.
El hidrógeno jugará un papel importante en lo que concierne al transporte sostenible. Esta tecnología forma parte de la transición energética y es importante incluirla dentro de los planes de descarbonización.
I’m yet to be convinced that hydrogen is suitable for LDV fleet, whether fuel-cell powered or engine propelled. In this application other hydrogen carriers like ammonia or methanol would be far better options. Much simpler to store. Heavy duty and stationary applications are different. Hydrogen would play a significant role in achieving low-cost zero emissions solutions. The key would be driving the cost of storage down. Particularly in stationary applications, it appears hard to compete with cheap 200bar storage.
Building a roboust H2 refilling infrastructure is essential. With better infrastructure in place, the storage capacity can be optimised which accelerates efficiency and sustainable mobility. Though energy transition got its attention, end of the day, commercial viability is the key for H2 in Green Mobility. Subsidy are not longer a trait for promoting green energy, as many countries started to terminate the subsidy for EVs
Le NH3 est une bonne alternative et ne pollue pas. Mais beaucoup de R&D avant un déploiement massif. Pour l'instant cela coute aussi cher de transformer le H2 en NH3 que de le compresser à 700 bars...sauf que...c'est plus rassurant pour les consommateurs...
Advanced nanomaterials and composites offer the promise of lighter gaseous hydrogen tanks, providing increased range without compromising on safety. While liquid hydrogen offers higher density and can store more fuel in less space, the complex and energy-intensive cooling infrastructure required for liquid hydrogen poses challenges. Alternative storage methods like metal hydrides offer high capacity and potentially quicker refuelling but require further development to achieve cost-effectiveness and efficient hydrogen release. Onboard hydrogen generation from readily available fuels like methanol is a fascinating concept, but it requires significant technological advancements.
Head or tail, there would always be more than one side to an issue. So the case of hydrogen storage in fuel cells isn't an exception. With well-funded, passionate R & D, a standardized, improved, and win-win storage model of hydrogen in fuel cells is possible. Before then, let's continue to innovate.