Hydrogen storage is now possible under much higher pressure
Thursday, 27 April 2023 15:30 |
Currently, about 80% of the energy consumed in the world comes from fossil fuels: gas, oil and coal. Both climate issues and limited natural resources motivate the effort toward the development of alternative and green energy sources. The disadvantage of most renewable energy sources is uneven operation, causing a need to store increasing amounts of energy. Hydrogen has the potential to account for more than 10% of total energy by 2050, both as a store of renewable energy and as a source of energy, if hydrogen can be extracted from underground sources. The product of burning hydrogen is only water, unlike fossil fuels, which generate carbon dioxide and other harmful gases when burned.
Undoubtedly, a major challenge on the road to efficient use of hydrogen is its storage. In gaseous form, hydrogen has an extremely low density. Its cubic meter weighs a mere 84 grams, which naturally means that its transportation and storage would be inefficient and thus far more costly than the liquid fuels currently in use. Therefore, various methods of storing hydrogen are being worked on. Depending on the application, these will include technologies using high-pressure hydrogen tanks, storage in liquefied form (which unfortunately requires cooling to extremely low temperatures of -253°C), as well as storage by absorption in metal hydrides or materials with developed surfaces, which are being worked on by a number of research groups around the world.
In response to this problem, a team of scientists and engineers from the Institute of High Pressure Polish Academy of Sciences (IHPP PAS) has developed a high-pressure double-walled hydrogen storage tank, which parameters exceed the currently used designs.
The solution was recognized by the Polish Agency for Enterprise Development (PARP) and the National Research and Development Center (NCBiR) in the XXV edition of the "Polish Product of the Future" competition. IHPP PAS received the main prize in the category of Polish Product of the Future of the Institutions of Higher Education and Science for the project "Safe hybrid (double-walled) hydrogen storage tank of high density stored energy with continuous pressure monitoring". The tanks developed at IHPP PAS can be successfully installed in cars or mobile hydrogen storage units, as well as prove themselves in stationary applications, i.e., for example, as storage tanks for solar energy produced by photovoltaic installations, where it is obtained by electrolysis of water.
(Fot. Karol Stanczak)
Energy from hydrogen can be obtained in two ways. The technologically mastered method is to produce energy directly by oxidation reactions of stored hydrogen in fuel cells (fuel cells). This energy can then be transferred to an electric motor that drives the vehicle. Hydrogen energy can also be produced by burning hydrogen directly in the car engine. Due to the very short ignition time, it is not possible to run the engine by burning hydrogen alone. On the other hand, using a mixture of standard fuel and hydrogen makes carbon dioxide emissions ten times lower than when burning gasoline or diesel fuel in a standard way. For the time being, the hydrogen buses that are already running on Warsaw streets, among others, use direct oxidation. Their refueling with hydrogen takes just 15 minutes and they can travel 450 kilometers.
The solution developed at IWC PAN by a team led by Andrzej Morawski, PhD, and Tomasz Cetner, PhD, makes it possible to increase the energy density of stored hydrogen by increasing the pressure inside the tank. The maximum pressure under which hydrogen can be stored in the tank they developed is 150 MPa, which is 1,500 times higher than atmospheric pressure. A car powered by hydrogen from this tank can already travel up to 700 kilometers.
The solution developed at IWC PAN exceeds the parameters of hydrogen tanks currently available on the market. The most technologically advanced company in this regard currently seems to be Toyota, which uses tanks with a pressure of 700 bar (70MPa) to store gaseous hydrogen, which is then used to power the cars they manufacture. A kilogram of hydrogen contains 120-140 MJ of energy, which is three times as much as a kilogram of gasoline, so technologies to increase the "energy density" per unit volume will directly translate into increased storage efficiency and longer range for hydrogen-powered cars.
A high-pressure double-walled HDPE liner hydrogen storage tank with a maximum working volume of 60 dm³ has been developed at IHPP PAS. It can store as much as 3.4kg of hydrogen. A huge advantage of the solution is its relatively low weight, only 75kg, due to the composite materials the researchers proposed to make the tank from. Due to the need to maintain a very high pressure inside, while at the same time a very high level of safety, advanced conduit technology was used and a two-level pumping system for the tank was proposed. This unique solution is already under patent protection. The tanks are tested under specially designed conditions. Safety is ensured by an innovative double-walled design and a special pumping system. It is certainly pleasantly surprising that the innovative solution proposed and tested by a team of only nine people from IWC PAN makes it possible to achieve twice as much pressure in the tank as that worked on by a huge department of a large Japanese company.
High pressure is in the institute's name for a reason!
Rysunek 1. Cross-section of a double-walled tank for hydrogen storage designed by the research team from IHPP PAS
In an era of increasing energy demand and advancing climate change, it is inevitable to look for alternative energy sources to complement current technologies. Hydrogen storage facilities could easily make it possible to store energy generated from renewable sources such as wind turbines or photovoltaic farms. The green electricity thus obtained could then be used to produce hydrogen, which can be efficiently stored and used at any time.
(Fot. Karol Stanczak)
Nagroda w Konkursie Polski Produkt Przyszłości za "Bezpieczny hybrydowy (dwupłaszczowy) zasobnik wodoru o wysokiej gęstości zmagazynowanej energii z ciągłym monitorowaniem szczelności" w wysokości 100 000 zł sfinansowana została ze środków poddziałania 2.4.1. POIR „Centrum analiz i pilotaży nowych instrumentów inno_LAB”
