Properties of Hydrogen
Hydrogen is a gas with a long history. Discovered in 1766 by the English chemist Henry Cavendish, it has been used as an industrial gas for over 100 years. Today, it is used in many industrial and technical processes.
When it comes to safety, hydrogen is often the subject of prejudices. In fact, hydrogen even has safety advantages over other fuels. Hydrogen (H2) is the lightest known element – about 14 times lighter than air. H2 forms an ignitable mixture with oxygen in a wide range (4 vol. % to 77 vol. %) –an explosive mixture with oxygen (oxyhydrogen gas) forms at a concentration of 18 % and above.
Hydrogen is non-toxic and cannot contaminate soils, the atmosphere or humans. In the event that hydrogen catches fire, the rate of combustion is relatively high. No smoke or fumes are produced unless other substances are burned.
(Green) Hydrogen production
While pure hydrogen exists in abundance in the blazing-hot interior of the sun and in the vastness of space, on earth it is only present in bonded form. Most of the hydrogen produced today is created as a by-product or co-product in processes of the chemical industry and is consumed again by the same industry. On an industrial scale, hydrogen is now mainly produced by reforming natural gas – a process that releases CO2 among other things.
Alternatively, hydrogen can be produced from water using electricity. This involves using an electrolyser to split water into its components hydrogen and oxygen – the energy used for this remains stored in the hydrogen. If the electricity comes from renewable sources, e. g. wind power, the hydrogen is emission-free – known as ‘green hydrogen’.
If the electrolyser is operated directly at the wind turbine, using hydrogen as a storage medium has another benefit: when the wind delivers more energy than is needed in the electricity grid at a given moment, this electricity can be temporarily stored in the hydrogen by splitting water. The gas thus assumes an important ‘buffer function’ in the intelligent electricity grid of the future.
Hydrogen (H2) safety
Fuel-cell vehicles are characterised by short refuelling times, long ranges, and powerful acceleration. They enable zero-emissions mobility for the purposes of a sustainable energy transition. Mobility powered by hydrogen and fuel cells is not only a safe bet when it comes to climate protection. It’s clear that handling hydrogen requires responsible handling — after all, it contains sufficient energy to propel a vehicle at high speed.
Safety during transport and storage
Hydrogen is transported in specially designed hydrogen trailers, using pressure levels of 200 bar, 300 bar or 500 bar. hydrogen is subject to the regulations for the transport of dangerous goods (ADR). This means that the transport vehicles used, as well as the drivers, must meet specified requirements. Alternatively, hydrogen can also be transported in cryogenic, liquid form in special, highly insulated tank trucks. In some parts of Germany, there are also hydrogen pipelines through which large quantities of hydrogen gas are transported to the customer.
There are various ways of storing hydrogen at the filling station, depending on the design of the hydrogen filling station, and the volume dispensed daily. Today’s facilities most commonly store hydrogen in a gaseous state at pressures of 45 bar or 200 bar. Storage in a cryogenic, liquefied state (-253 °C) is also possible.
Safety during refuelling
The hydrogen fuel pump communicates with the vehicle via an infrared interface. The vehicle has a communication interface directly next to the tank nozzle, which provides the filling station with data on pressure and temperature in the tank. This data is compared with the measurements taken at the filling station. If there are certain deviations, the service station interrupts or stops refuelling in order to check the reason for the deviation. In addition, the vehicle can stop the refuelling process – an additional safety feature that does not exist for any other fuel.
The refuelling line connection to the car is a so called ‘closed connection’ meaning: No hydrogen escapes during the refuelling process – otherwise the vehicle could not be refilled. It’s very similar with bicycle tyres: if you don’t have a good seal and the air blows past the valve, the tyre doesn’t fill up. To prevent this happening at the hydrogen filling station, the filling station first checks the fit of the nozzle and the tightness of the line. If one of the two is not right, the refuelling process will not start. The filling station uses a control system to ensure that the car is full, but not overfilled. As an additional safety measure, overpressure valves are installed in the vehicle tank to reliably limit the pressure.
After refuelling, the nozzle and the tank hose are “depressurised”: The hydrogen is fed back to the station. Only a very small and therefore harmless amount of hydrogen remains at the nozzle – about one third of a shot glass.
Safety in the vehicle
In terms of safety, hydrogen-powered vehicles are no different from conventional means of transport. This has been demonstrated by independent test services such as Germany’s TÜV in various crash tests and test series. Even if hydrogen is highly flammable, there is no increased risk in the event of an accident. Rather, hydrogen-powered vehicles are safer than conventional gasoline engines – because hydrogen doesn’t explode.
A leak in the hydrogen tank is very unlikely. And even if a leak should occur, the sensors detect the escaping hydrogen. The vehicle is automatically switched off and all safety valves are closed. The hydrogen tank is tested at 2.25 times the permitted operating pressure – i. e. a 700-bar-tank must withstand a pressure of at least 1 400 bar and has high safety reserves in the event of an accident. The hydrogen tank is extremely resistant to internal and external pressure as well as to fire.
Questions about payment & billing
How do I pay for the hydrogen I’ve refuelled my vehicle with?
In Germany, invoices are sent by post or email using H2.LIVE/CARD. If you don’t want to transfer the invoice amount each time, you can select ‘SEPA mandate’ in the card application form or subsequently request it by sending an email to email@example.com. However, there is one exception: you will need a credit card to refuel at the station in Frankfurt-Höchst.
The station’s app/web details screen tells you how to pay at the various hydrogen filling stations outside Germany. But we are also happy to provide the information directly: simply write to us at firstname.lastname@example.org. specifying the country.
If you wish to change your payment method or have any other questions, please contact us at email@example.com and include your username.
Since June 2022, it is also possible to pay with the DKV fuel card or by using the Euroshell fuel card.
From the end of the year, the refueling process will be even easier: digital payment via H2.LIVE app will be introduced at all H2 MOBILITY service stations. Then you authenticate directly via app from the car.
Where will my invoice be sent?
The invoice is always sent to the address provided in the card application. If you have a question about a specific H2 invoice or wish to change your billing address, please send an email to firstname.lastname@example.orgWill I get a receipt directly at the hydrogen filling station?
Yes. You can request and retrieve a receipt from the card terminal during authorisation or after completing the refuelling process.
Do I have to enter the filling station shop to pay?
In Germany you do not have to enter the filling station shop to pay. Payment for hydrogen is usually made by invoice directly via your H2.LIVE/CARD. For information in other countries please refer to the station details.
Can I view my fuel data?
Yes, but only if you are a private customer or if your company has approved this service for you. Then simply pull up the tab on the app or go directly to ‘My H2.LIVE’ on the Internet and download your fuel data under ‘My refueling data’.
How much does hydrogen cost at H2 MOBILITY filling stations?
Hydrogen is charged in kilograms. The price for a kilogram of hydrogen at all public H2 MOBILITY filling stations is €12.85 (gross). For 100 km, a fuel cell vehicle consumes approximately 0.8 kilograms of hydrogen (WLTP), generating fuel costs of €10.28. An equivalent journey with gasoline or diesel and an assumed average consumption of 6.6 liters at a fuel price of €1.90 costs €12.54 in comparison. The price for charging 19 kWh at a public charging station is €11.21. (Source: ADAC 2022 and BMDV 2021)
When and how will green hydrogen become affordable?
By scaling but mainly by changing rules and regulations: With the Renewable Energy Sources Act (EEG) the legislator wanted to promote investments in wind power, solar and biomass plants. This has been successful.However, this law also stipulates a fixed remuneration for electricity that cannot be fed into the grid due to bottlenecks. This remuneration is refinanced by all consumers.
Electrolysers are regarded as end consumers and therefore have to pay the EEG levy, like all consumers. The Act therefore currently does not create any incentives for the sensible use of electricity that is not produced in line with demand, because the wind farmer, the photovoltaic operator or the biogas company receives compensation anyway. Moreover, the electricity for electrolysis becomes so expensive that it is not economically viable.
This is now to change within the framework of the National Hydrogen Strategy. It also prescribes the establishment of 5 GW electrolysis capacity by 2030. This remuneration is refinanced by all consumers.
Since electrolysers are considered end consumers, they have to pay the EEG levy even if they store the electricity that can no longer be fed into the grid. The Act therefore currently does not create any incentives for the sensible use of electricity that is not generated in line with demand, because the wind farmer, the photovoltaic operator or the biogas company receives compensation anyway. Moreover, the electricity for electrolysis becomes so expensive that it is not economically viable.
This is now to change within the framework of the National Hydrogen Strategy. It also prescribes the establishment of 5 GW electrolysis capacity by 2030.This now also results in a scaling.
New here? Information about the H2.LIVE/CARD
How do I get an H2.LIVE/CARD?
It’s easy! Register through our H2.LIVE app or online (www.h2.live) in the ‘My H2.LIVE’ section, and apply for your free personal H2.LIVE/CARD. Please confirm that you have completed the video tutorial. You can manage your information on ‘My H2-LIVE’. We will gradually activate more and more features and functions. You will receive the card by post within five working days. It is ready for use. You will find the pin on the back of the card. If ever you wish to delete your account, just send us a message to email@example.com.
Why do I need an H2.LIVE/CARD?
A personal H2.LIVE/CARD is required for hydrogen refuelling at all public hydrogen filling stations in Germany (exception: the industrial estate in the Höchst district of Frankfurt: here, you will need a credit card). The fuel card is used to authenticate yourself at the terminal. It also serves to assign your refuelling data in the billing process. Unfortunately, the H2.LIVE/CARD isn’t valid outside Germany at this time – but we’re working on it! Our goal is to ensure hydrogen-powered mobility across borders
Why do I need a tutorial to apply for an H2 fuel card?
In principle, refuelling with hydrogen is almost like filling up with petrol. Remove gas cap, insert nozzle, done. The only significant difference is in the physical state of the fuel: hydrogen is gaseous! So there are some differences. To ensure that all hydrogen pioneers know how refuelling with hydrogen works, we’ve made the tutorial a prerequisite for the card application.
Forgot your PIN? Lost your card? Want more cards?
Who do I contact if I’ve lost my card, want to block it, forgot my PIN or need more cards? Please write to firstname.lastname@example.org.
VIDEO: It`s just as easy to refuel your car with hydrogen
How do I fill up with hydrogen?
At our stations there are two different tank couplings. In the movie we show how to refuel with both. You can also download the refuelling instructions as a PDF file here:
Refuelling instruction_WEHRefuelling instruction_WALTHER
Our hydrogen stations are all similar, but have small differences depending on their manufacturer. What all stations have in common is a card reader next to the fuel pump. The reader is either integrated into the dispenser or is very nearby. Insert your fuel card into the reader with the magnetic strip facing down to the right, and then simply follow the instructions on the display.
Depending on the configuration of your fuel card, you may also be asked to enter the current mileage and license plate number of your vehicle.
Remove the dispenser by lifting it upwards out of the slot and then moving it away in a downward direction. After you have opened the fuel tank flap and removed the tank lid, the dispenser nozzle can be placed on the vehicle’s tank nozzle.
There are two different types of coupling at our stations: either the tank coupling locks automatically, or the fuel nozzle has a lever for locking it into place. In the latter case, pull the lever upwards to lock the nozzle, and make sure that the locking ring is snapped forward on the tank coupling. Always check that the fuel nozzle is properly locked into place.
You can then start the refuelling process simply by pressing the green button on the dispenser. Don’t be startled – there is a test surge at the beginning, as the system tests whether the connection is secure and how much hydrogen is still in the tank. The refuelling process ends automatically and the green button lights up or stops blinking. Now you can release the locking device by activating the small crossbar on the fuel nozzle lever or by pressing the white button on the fuel coupling’s locking ring and pulling the ring towards you.
Hang the dispenser back into place, going from the top down. Please check that it is correctly engaged, otherwise the system will not be able to complete the refuelling process and prepare for the next refuelling. Now just close the fuel filler flap and enjoy your next 500-700 kilometres of emission-free driving!
Why does it hiss?
Your car and our dispenser communicate via an infrared interface. As soon as the tank hose is locked, the filling level of your tank is determined by a test surge. After a short pause, the refuelling process begins. Don’t worry about a hiss when the gaseous hydrogen is pressed into the tank and the hose tenses. In Linde systems, you can monitor the rising pressure in the tank via a pressure gauge on the side.
Replace the dispenser properly! Why this is so important.
Only when a refuelling process has been completed can the system begin to prepare for the next refuelling and build up the necessary starting pressure. A properly engaged dispenser is a prerequisite for this. Please be careful to do this after refuelling.
Is there a support hotline in case of problems or malfunctions?
We offer a 24/7 support hotline for all H2 MOBILITY stations: +49 800 400 20 23. Please use it only if there is a malfunction! If you require help or support at a station run by another operator, please contact the telephone number shown in the details window of the station.
Why does the refuelling take longer on hot days?
When refuelling an H2 vehicle, heat is generated as the pressure in the tank increases. For this reason, the hydrogen is pre-cooled before it is refuelled. At high outside temperatures, starting at about 28 °C, we slow down the cooling a little bit to better counteract the compression heat and the high outside temperature. Therefore the refuelling takes a little longer.
My car won’t fill up completely – What can I do?
The maximum filling level for vehicles can vary between individual H2 filling stations. Factors such as the outside temperature are also responsible for this. The average filling level is approx. 97 %. If your refuelling unexpectedly ends at less than 85 %, you can repeat the fuelling process. To do this, end the current refuelling process, including replacing the dispenser. Then restart the process by registering with your fuel card. If you still have difficulties, please contact the operator or the local support hotline.
Ice on the fuel nozzle – What does it mean?
Anyone who has ever inflated a bicycle tyre knows that it warms up as the pressure rises. We refuel hydrogen at 700 bar! The H2 is pre-cooled in our systems, to between -33 °C and -40 °C. So it can happen that ice forms on the nozzle when there is high humidity.
Difficulties when removing the fuel coupling
Our H2 systems are pre-cooled because refuelling under pressure generates heat. In some older systems, cooling may cause the coupling to briefly ‘freeze onto’ the car’s tank nozzle. If the coupling is stuck, simply push the coupling towards the car and then remove it. We are gradually retrofitting all older systems, as the problem has been eliminated in newer couplings.
How do I refuel hydrogen outside Germany?
At this point, the H2.LIVE/CARD is valid only in Germany, but we are working on introducing payment across borders. If you plan to travel abroad, we already have plenty of information available for you in the App/Web details window of the individual filling stations. We are also happy to provide information directly: Simply send us an enquiry with the destination country to email@example.com. We will contact you with the country-specific details
Can I submit feedback about filling stations or any refuelling problems I experience?We welcome and need your feedback! Please use the feedback section of our H2.LIVE app to submit your wishes, constructive criticism, suggestions for individual stations or about the hydrogen infrastructure in general. Or email us at firstname.lastname@example.org. Thank you!
Where does the hydrogen at the hydrogen filling station come from, and how ‘green’ is it at the moment?
At H2 MOBILITY, we are building a nationwide hydrogen infrastructure for Germany because we believe that using hydrogen as a propulsion energy will significantly reduce road traffic-related emissions. To achieve the greatest possible effect here, our goal must be to offer hydrogen that is 100 % from renewable sources.
We already have facilities that offer hydrogen produced by water electrolysis (e. g. in Wiesbaden and Brunsbüttel), and as a company we are committed to ensuring a steady and rapid increase of these renewable sources of hydrogen in Germany. At present, however, it is still a great challenge to obtain sufficient green hydrogen. The reason is that there is simply not enough green hydrogen available. However, this will soon change thanks to national and international hydrogen strategies.
In 2020, the average share of green hydrogen in the grid was 28 %. It is produced from water electrolysis and from biomethane and biomethanol, and is certified green by TÜV. Our goal is to successively increase this share.
30 % of the H2 offered by H2 MOBILITY is by-product from the chemical industry that would otherwise go unused.
The remaining 42 % is (still) produced from natural gas. And though hydrogen produced from natural gas saves about 1/3 CO2 compared to conventional fuels, our clear goal remains: green hydrogen, preferably produced with electrolysis using renewable energies.
How much effort does it take, or how cost-intensive is it, to upgrade a conventional filling station with hydrogen dispensers and tanks?
So far, we have mainly installed S-size hydrogen filling stations. Here, 200 kg of hydrogen are stored for refuelling at 700 bar. That is enough to refuel 40 vehicles. Integrating this kind of filling station into a conventional station costs about 1.2 million euros.
Starting in 2021, we are also building larger stations that can supply commercial vehicles with hydrogen at 350 bar and hold 400-800kg of hydrogen. We estimate the costs here at 2.5 million euros. Construction takes between 12 and 20 months. Most of this time is taken up by the application and approval procedure. Apart from that, it is an engineering feat in which we now have the greatest experience worldwide.
To what extent is the expansion of hydrogen filling stations supported by the state or otherwise?
H2 MOBILITY receives funding from the Federal Ministry of Transport and Digital Infrastructure (BMVI) under the National Hydrogen and Fuel Cell Technology Innovation Programme (NIP), and from the European Commission as part of the Hydrogen Mobility Europe project, which receives funding from the Fuel Cells and Hydrogen 2 Joint Undertaking (FCH 2 JU, grant agreement no. 671438). The FCH JU is supported by the European Union’s Framework Programme for Research and Innovation (Horizon 2020), Hydrogen Europe, and the Hydrogen Europe Research Association.
What does the H2.LIVE map show me?
Welcome to H2.LIVE!
Every 2 minutes, we pull live information from public hydrogen stations all across Europe where you can refuel with hydrogen at 350 and/or 700 bar! This means that you are always fully up to date with H2.LIVE online (www.h2.live) or the H2.LIVE app.
A brief explanation of our map. You can choose right at the beginning: Are you interested in 350 bar (mainly for buses and commercial vehicles) or 700 bar (mainly for passenger cars, but also refuse collection vehicles)?When you zoom in on a country, green and red dots become visible. Green dot: This station is available. Red dot: You can’t fill up here at this time. See where we are currently building stations with the blue dot. The extent to which the circle is filled shows how far construction has progressed at that site.An exclamation mark by a green station usually indicates maintenance dates; by a red station it informs you when the station will start operating again. If a station is unavailable due to its opening hours, the red dot is marked with clock hands. If we didn’t receive any live information, we assume that it is possible to refuel, but will put a question mark by the station.
For each station you will also find additional details, including its address, operator, opening hours and usually also contact details. Just click on the dot.
Tell us what you think! Share your thoughts with us!
If you have praise, criticism, or suggestions, we would love to hear from you – including about individual stations. Which is why we’ve included the option of opening a form via each individual station’s details page (simply click on the station) in the app. You can even upload photos – or send us general feedback comments here. Thank you!
What is H2 MOBILITY and what is H2.LIVE?
H2 MOBILITY Deutschland GmbH & Co.KG is our company, tasked with establishing a nationwide hydrogen infrastructure in Germany, i. e. building and operating hydrogen stations. H2.LIVE is our digital service, which among other things maps the entire European infrastructure.
H2 MOBILITY Deutschland was founded by the partners Air Liquide, Daimler, Linde, OMV, Shell, and TOTAL and is responsible for the nationwide establishment and operation of a hydrogen infrastructure to supply cars with fuel-cell drives in Germany. We handle all of the operational tasks, including network planning, permitting, procurement, construction, and operation. Our first goal is to operate 100 hydrogen stations in seven German metropolitan areas (Hamburg, Berlin, Rhine-Ruhr, Frankfurt, Nuremberg, Stuttgart, and Munich), and along the connecting arterial roads and motorways, in the course of 2020 regardless of vehicle numbers, as a prerequisite for hydrogen mobility. After this, we will continue building depending on demand and the market ramp-up of fuel-cell vehicles.
H2.LIVE is the digital refuelling service that can be downloaded free of charge as an app from the App Store and Google Play or online at www.h2.live. Here you can get real-time information about individual stations, find out when maintenance is planned, or apply for a fuel card. The H2.LIVE offer is constantly being expanded. Stay tuned!
Questions about fuel-cell vehicles
Above all in terms of sustainability: when is a battery electric car better and when a fuel cell vehicle?
In order to meet the challenge of the mobility revolution and to meet the climate targets, we will need both technologies – the battery for short distances of less than 250 km and hydrogen and fuel cells for long distances and whenever short refuelling times are required (e. g. in taxi operation). See also here: https://h2.live/wp-content/uploads/2019/07/ISE_Ergebnisse_Studie_Treibhausgasemissionen.pdf.
A current study of the ADAC here: https://stiftung.adac.de/app/uploads/2019/06/IBeMo_Abschlussbericht_final_190625_LBST_Zerhusen.pdfDoes heating in winter impair the range of fuel cell vehicles as is the case with battery electric vehicles?
Hydrogen vehicles have the advantage that a by-product of the chemical reaction of hydrogen with oxygen is heat. This can be used for heating in winter. Nevertheless, the consumption of hydrogen vehicles is slightly higher in winter than in summer. This is due, for example, to the fact that the fuel cell must be brought to operating temperature after starting. However, the additional consumption of a H2 car in winter is much lower than in a battery electric car.
When a hydrogen car is parked in the garage for a few days, does the hydrogen evaporate?
No. This was actually a problem at one time when the hydrogen was carried in the car in a cryogenic state, i. e. at -253 °C in a liquid aggregate state. This low temperature simply cannot be maintained for long periods of time. The hydrogen heats up and becomes gaseous again; in other words, it expands and the valves “blow off”.
How long is the holding time of a fuel cell?
Evaluations e. g. of fuel cells from the CleverShuttle fleet, a ride sharing service, after 180 000 km of mileage, have shown that fuel cells have a long service life. In the case of the CleverShuttle vehicles, the performance was still 98 %!
When will fuel cell vehicles be affordable?
Costs will decrease mainly due to scaling. If the number of fuel cells or the number of cars built increases, the price of fuel cell cars will also decrease. Toyota and Hyundai have announced higher production volumes of up to 30 000 units/year from 2020/21 for the Mirai and NEXO models.
Will fuel cell vehicles also be promoted?
Yes, the acquisition of at least three fuel cell vehicles will be promoted within the framework of fleet subsidies in the National Hydrogen and Fuel Cell Technology Innovation Programme (nip) by the Federal Ministry of Transport (BMVI). Toyota and Hyundai also pass on the support outside of fleets, mainly in the form of leasing offers. The amount of the subsidy depends on the current call, but in the past it has amounted to up to 16.000 euros.
What vehicles are currently available for rent, lease or purchase?
Click here to see an overview of all fuelcell car models
Can buses, trucks and other commercial vehicles refuel at all hydrogen filling stations?
No, there are still only a few stations where buses and/or trucks can refuel. On the one hand, the pressure level is decisive. While hydrogen passenger cars carry the H2 with a pressure of up to 700 bar, commercial vehicles that have more space for the on-board hydrogen storage can guarantee long ranges even with a pressure of 350 bar. Today, it is mainly hydrogen buses that operate with 350-bar-technology.
Even for commercial vehicles with 700-bar-technology not all stations in the network are suitable. Here, the compressor size is particularly decisive. While passenger cars fuel 4 kg on average, a hydrogen commercial vehicle requires up to 20 kg of hydrogen, for example.
The primary task of H2 MOBILITY is to establish a public hydrogen infrastructure for passenger cars – i. e. 700-bar-technology and small delivery volumes. With the increasing demand for H2 commercial vehicles, such as buses or trucks, we have expanded our strategy. To find out whether a station is suitable for a specific commercial vehicle, please contact Frank Fronzke directly at email@example.com.
Which vehicle tanks are available and how do they affect the refueling of heavy-duty vehicles?
The vehicle tanks of fuel cell vehicles are classified as Type III or Type IV. Type III vehicle tanks consist of an aluminum container encased in carbon fiber. Type IV vehicle tanks use a plastic container instead of the aluminum container. This makes them lighter, but they also heat up more during refueling than Type III vehicle tanks. When refueling heavy-duty vehicles with Type IV tanks, it is therefore necessary to pre-cool the hydrogen.
To ensure that all vehicles can refuel with us without restriction in the future, we are currently equipping all H2 MOBILITY 350-bar hydrogen refueling stations with pre-cooling. If you are a user, please check the location descriptions to see whether a station is suitable for refueling your vehicle.
Information about the LOHC technology
What is or what are LOHC?
LOHC, i. e. Liquid Organic Hydrogen Carrier, stands for liquid hydrogen carriers consisting of carbon compounds. There are different carriers such as benzyltoluene, dibenzyltoluene, toluene or N-ethylcarbazole. All of them have different properties. But basically, you can think of these carriers like a deposit bottle: This is because the hydrogen can be bound to the carrier substances and removed again when the energy carrier is needed. LOHC technology is thus a method of interim storage and transport of hydrogen.
How does the LOHC technology for hydrogen storage and transportation work?
The basis of LOHC technology is a chemical catalytic process. In Hydrogenious’ proprietary technology, hydrogen molecules are bonded by hydrogenation to the non-toxic and very low flammability carrier medium benzyltoluene (this is a thermal oil). Dehydrogenation of the LOHC, i. e., the release of the hydrogen from the carrier material, also occurs in a chemical reaction. Hydrogen storage is an exothermic reaction (heat release), while hydrogen release is an endothermic process (heat demand).
What is the efficiency of the technology?How much energy is required for storage and release? What is the energy balance?
LOHC loading and unloading are complementary chemical processes in terms of heat. That is, the heat released during hydrogenation is equal in amount to the amount of energy required during dehydrogenation. In the process of dehydrogenation, however, losses occur due to waste heat, so that somewhat more energy must be added for the release than for the storage. An optimization is already being worked on; in terms of efficiency, Hydrogenious always follows the approach to install its LOHC injection plants where the waste heat can be usefully utilized (e. g. for household heat supply in the Aqua Portus/Helgoland project) or to place its LOHC release plants in the direct vicinity of external heat sources, as can often be found in industry (and industrial hydrogen demand is currently/immediately the largest need/market for LOHC).
What is the purity of Hydrogenious’ released hydrogen?
The purity level can be adapted to the customer’s needs. In principle, storage plants can release hydrogen up to a purity level of 99.99 %. It therefore meets the requirements for fuel cells and complies with ISO 14687:2-2012 and SAE J2719 standards, which is essential for use at hydrogen refueling stations.
What is the storage capacity of the carrier material?
Here, in view of the function of LOHC, namely to transport hydrogen in very large quantities safely and easily over long distances, it is necessary to distinguish between two aspects, namely gravimetric and volumetric energy or storage density. In particular, volumetric density, combined with safety and ease of handling, also accounts for the particular suitability of LOHC-BT.
Volumetric (the energy per volume of space of a substance) >> Here, the current rule of thumb is that a single LOHC tanker can transport up to five times as much hydrogen as a compressed hydrogen trailer.
Gravimetric (a measure of the energy per mass of a substance) >> One cubic meter of LOHC can store 57 kilograms of hydrogen.
What are the advantages of Hydrogenious’ LOHC technology?
The benzyltoluene used by Hydrogenious as LOHC is characterized, beyond high safety, by the following:
It can be transported without loss and stored for long periods of time.
It is easily handled under ambient pressures and temperatures, even under cold conditions similar to diesel, so it can be handled within existing fuel logistics infrastructure.
Its (volumetric) energy density is extremely advantageous, as a transport container can store about 5 times more energy compared to compressed hydrogen.
Thus, for example, hydrogen can be stored underground in densely populated areas to save space.
BT is widely used in industry and is therefore commercially available in large quantities. It can also be loaded and unloaded with hydrogen many hundreds of times and is recyclable.
For high-volume port-to-port supply chains, LOHC is projected to have a very competitive total cost of ownership for hydrogen transport compared to ammonia, which additionally plays up its superior safety and handling with respect to ports as future high-volume hub locations.
What are the disadvantages?
Young technology with still limited industrial experience, but reliance on high maturity of today’s fuel infrastructure.
A larger amount of thermal energy is required to release hydrogen, see above (but similar to ammonia, with LOHC at much lower temperatures).