by Sieb Rodenburg
I always love to talk about hydrogen and the energy transition, so feel free to contact me if you have any questions or want to collaborate. If you want to dig even deeper into the subject then please listen to our podcast ‘De Waterstofpodcast’ where we discuss hydrogen with experts in the field. The podcast is in Dutch and is available on Spotify, Apple, or Google podcasts.
What is hydrogen?
Hydrogen is the first and simplest atom in the periodic table and consists of one proton and one electron. It is also the most abundant element on earth. When we speak of hydrogen we tend to mean dihydrogen, meaning two hydrogen atoms forming a molecule as seen below. However, this form of hydrogen does not occur naturally on earth. In nature hydrogen is always coupled with another element, for example oxygen in water or carbon in natural gas or oil. With different kinds of techniques you can subtract the hydrogen from its original form.
Currently the most used method to win hydrogen is steam methane reforming, in which methane is divided into CO₂ and hydrogen with steam. This CO₂ is emitted into the atmosphere, and is therefore called grey hydrogen. We can already capture this CO₂ and store it underground in for example old gas fields, which saves 80-90% of CO₂ emissions. (TNO, Peters, 2020) When this is done we call it blue hydrogen. Of course this way of producing hydrogen is still not future proof, because fossil fuels are still used in the process. To make sustainable hydrogen, also known as green hydrogen, we use renewable electricity for example from windmills or solar panels. With this electricity water is divided into hydrogen and oxygen in a machine called an electrolyser.
Even though hydrogen is seen as an energy carrier of the future, hydrogen production already plays a big role in our energy mix, taking up 6% of our total natural gas use and 2% of our coal use globally. (IEA, 2020) The biggest consumers are oil refineries and the fertilizer industry.
In the future, hydrogen will become important in all sections of our life. It will grow very large in industry, as a feedstock, but also for high temperature processes. It will play an important role in mobility, especially in heavy and long-haul transportation, such as for trucks, busses, trains, boats and airplanes. It can play a role for spatial heating of our homes and other buildings, where electrification or a heat grid will not be sufficient. It will become a crucial factor in moving and storing energy, since hydrogen is both easier and cheaper to store or move compared to electricity.
These are only just a few examples for hydrogen’s wide variety of possible applications, so do not forget to scroll through our website and discover the wonders of hydrogen and hopefully you will get inspired to work or investigate in the field of hydrogen as well.
Where did it all begin?
The first applications of hydrogen were seen in for example the hippomobile, one of the first ever combustion engine vehicles. This car was driven on a mix of hydrogen and carbon monoxide, which was a product made from coles. Another early use was in zeppelins. Both hydrogen and helium are lighter than air, which makes it possible to let a zeppelin fly. A famous zeppelin with a not so happy ending that flew on hydrogen was the Hindenburg, a zeppelin that flew between Germany and the United States before the second world war. The Hindenburg crashed into an electricity cable and caught fire. A fable is that this was caused by the hydrogen, but is more likely that the skin and wooden body burned, because hydrogen rises with a speed of around 20 m/s and therefore had already disappeared before it could burn. Another famous use was in space exploration. Except for a lot of kerosine and liquid oxygen, the Saturn V rocket that brought the Apollo 11 to the moon used more than 1.2 million liters of liquid hydrogen. The Eco-Runner X would be able to drive to the moon and back 285 times with this amount of hydrogen.
How safe is hydrogen?
Hydrogen is a combustible gas, and is therefore feared sometimes. The most dangerous features of hydrogen are its flammability and ignition limits. Hydrogen can ignite in a hydrogen-oxygen mixture between 4-77%, compared to an ignition range of beneath 20% for most fossil fuels. This asks for safe handling of hydrogen, but because it is already used in industry for so many years, all this knowledge is available and ISO standards have therefore long been made. Since 2015 standards have also been set on safe handling of hydrogen in cars and other applications. (ISO/TC 197)
Because we are used to using fossil fuels for over 100 years now, we are accustomed to dealing with them but tend to forget the dangers. Oil or natural gas are both very dangerous substances. A petrol leak will for example pool close to the ground, largely increasing incineration likelihood. If a leak occurs in a hydrogen tank the very volatile hydrogen will escape into the air quickly, not causing this extra danger. The advantage of the volatility can also be seen in the ignition experiment below, conducted by the US department of energy. For domestic usage hydrogen is also safer than natural gas. It diffuses 6 times quicker and is less toxic when breathed in. Just like natural gas hydrogen is scentless, so an indicator will be added when moving hydrogen into our homes.
How is hydrogen made?
Hydrogen is only found on earth in bound form, so it is always made with a certain production method. Most of today’s hydrogen production is based on fossil fuel energy sources. 68% of global and almost all European hydrogen is made with steam methane reforming, a technique which splits methane into CO2 and hydrogen with steam under high pressure.
CH4 + 2 H2O → CO2 + 4 H2
Today this CO2 is emitted into the atmosphere, this is called grey hydrogen, but technology is already there to capture this carbon and store it under the ground. Hydrogen produced this way is called blue hydrogen. The carbon will be captured during the production, moved under pressure in tubes and can be put in for example old gas fields, 2 to 5 km under the ground. This can save 80-90% of carbon emission during hydrogen production. Although this technique is not yet applied on a large scale the plans are there to start producing blue hydrogen in the Port of Rotterdam and store carbon underneath the north sea. This project is called project H-Vision. This area is ideal not only for its location near the north sea, but also because of the high current demand for grey hydrogen in the area for oil refinery and fertiliser industry. (TNO,2020) (Shell, 2020) (H-vision, 2020)
Eventually blue hydrogen production still emits carbon dioxide and still uses fossil fuels, so a sustainable way of producing hydrogen is needed. When hydrogen is produced in a sustainable way we call it green hydrogen. Even though hydrogen production through algae or biomass is possible, hydrogen production through electrolysis of water with green energy, such as solar or wind, will play the biggest role.
The most common type of electrolyser is the alkaline electrolyser which has been used in industry for over more than 100 years. An alkaline electrolyser consists of a DC source and two electrodes, splitted by an electrolyte. The cathode (negative pole) loses electrons to the water splitting it in hydrogen and hydroxide ions.
2 H2O + 2 e- → H2 + 2 OH-
At the anode (positive pole) the hydroxide ions form water and oxygen and release electrons.
2 OH- → H2O + ½ O2 + 2e-
Electrolysers are differentiated by different electrolytes and different operating temperatures. The alkaline electrolyser has an efficiency of around 60-80%, but there are newer technologies being scaled up today that are promised to reach way higher efficiencies. (Shell, Wuppertal Institut, 2020)
How can hydrogen be transported and stored?
A large advantage of hydrogen compared to electricity is that it can be moved and stored quite easily, just like natural gas or any gaseous molecule. Transport of hydrogen through pipelines can be 10-20 times cheaper than transport of electricity through a cable and large scale storage is at least 100 times cheaper than storage of electricity in a battery. (Van Wijk and Wouters, 2019) (Van Wijk, 2020) Therefore hydrogen will play a big role in storing renewable energy and transporting it around the world. This can compensate for the fluctuating energy production caused by renewables and the larger energy demand we have in winter.
Green hydrogen can be transported in different ways, of which the cheapest is through pipeline. The European Union is building a hydrogen backbone that will transport green hydrogen through Europe. This backbone is planning to connect most parts of the EU by 2040. (European Hydrogen Backbone, 2020) Hydrogen has a low volume density so is compressed when moved through pipelines. With some modest adjustments our gas network can be transformed into a hydrogen network. Around 75% of the European hydrogen backbone will consist of retrofitted infrastructure, while only representing 50% of total investment. The total investment is expected to range between 27 and 64 billion euros, of which 60% will be dedicated to pipeline works and 40% compression equipment. This seems like a lot of money but is quite a small amount compared to the hundreds of billions the European Commission expects for other hydrogen investments, like electrolysers and green energy to make hydrogen. (European Hydrogen Backbone, 2020) (Kiwa, 2018) (European commission, 2020)
An example of possible storage and transportation of energy;
What is hydrogen used for today?
Today almost all hydrogen produced is for Industry. The two largest uses of hydrogen are as feedstock for oil refinery and ammonia production. Ammonia is the main feedsock for fertilisers. Fertilisers are a large part of what made it possible to feed the 8 billion people living on earth today and are very important to feed the projected 10 billion people living on earth in the near future. Ammonia production accounts for around 55% of hydrogen use, oil refineries account for 25% and methanol production another 10%. Methanol is used as feedstock for the fabrication of all kinds of polymers. The last 10% is for all different kinds of uses, for example for making flat glass, or as protection gas making computer chips to be sure there is no oxidation. In total hydrogen production is good for 830 million tonnes of CO₂ emissions annually. (IEA,2020) (Hydrogen Europe, 2020)
The future uses of hydrogen
Hydrogen is being scaled up very rapidly. The EU has planned to supply all current industry with clean hydrogen by 2024 and make hydrogen an integrated part of our energy system by 2030. It is projected that the share of hydrogen in the european energy mix will be around 13-14% by 2050. This is because of its crucial role in the hard-to-decarbonise sectors and energy storage. Overall there are 3 ways of using hydrogen; As a fuel to make electricity, to burn and make heat and as a feedstock. (BloombergNEF, 2020) (European Commission, 2020)
Hydrogen in mobility
Except for using hydrogen in city cars, hydrogen will be used very broadly in mobility, of which the biggest category is the heavy and long haul transport. Some examples are trucks, intercity busses, trains, boats and airplanes. Hydrogen and hydrogen technology like fuel cells will drop drastically in price due to upscaling, this will make hydrogen a challenger for batteries in these sectors. Other reasons are for example that the energy to weight ratio is ten times larger than that of a battery. This is very important in aviation, but also in for example the maximum load of a truck.
Another advantage is a long range. The price of the hydrogen tank is relatively low compared to the price of the fuel cell, which makes upscaling the tank, thus the range, cheaper than upscaling a battery, which is the most expensive part of the battery electric vehicle’s powertrain. Another thing to take into account when upscaling a battery is that the greenhouse gas (GHG) emissions of battery production takes up around 50% of the total GHG emissions of a battery electric vehicle in its lifetime. (Deloitte, 2020) The refuelling time also plays a role when choosing hydrogen or battery electric. Refueling a Fuel Cell electric car can be done in just a few minutes, where recharging a battery takes longer.
Hydrogen in industry
Hydrogen can serve two great purposes in industry, in chemical reactions and as fuel. A good example of hydrogen in chemical reactions is for example as a feedstock in fertilizer industry, but also in for example the steel industry. Current steel production is good for around 8% of global GHG emissions, of which most originate in making raw iron from iron ores (FeO). For this heat is needed, but also a molecule to bind to the oxides. In today’s steel industry this is the carbon from fossil fuels, forming CO2. One of the few other materials that can also supply heat and can bind with the oxides is hydrogen, forming H2O. Project HYBRIT is a testing facility in Sweden that uses hydrogen for steelmaking, and they are planning to make ‘green’ steel marketscale in 2026. (Eurofer, 2019) (HYBRIT, 2020)
The second role for hydrogen in industry is as a fuel. High temperature processes are very hard to electrify. Therefore burning green hydrogen is very likely to be needed for processes of +400℃.
Hydrogen in the built environment
To make our homes fossil-free the biggest challenge is finding a solution for our heat, such as for cooking, showering and heating in winter. In the average Dutch household heat takes up around 80% of the energy demand, and this is currently almost fully supplied by natural gas. There are very nice solutions for this like a heat pump or a heat network with waste heat or geothermal warmth. These solutions do have some ifs and buts though; A low-temperature heat network or heat pump requires very good insulation for instance, which is hard for monuments. A heat network requires a sustainable heat supply near and isn’t cost efficient in more remote areas with a low connection density. Therefore it is more likely for some areas to use heat supplied by a sustainable gas, like biogas or hydrogen. Stedin, the grid operator in our province, expects around 30-40% of the households in their workfield to be heated with a sustainable gas. Hydrogen can be supplied to our houses in multiple ways. It is possible to move hydrogen through our gas pipes and provide the full heat demand with hydrogen together with a hydrogen boiler. It is also possible to use a hybrid heat pump together with hydrogen, where the heat pump will deliver a base load and hydrogen will supply the extra heat when the heat pump isn’t sufficient.
Crashcourse Waterstof [NL]
Are you curious about hydrogen and want to know (almost) everything in just less than 5 minutes? Check out the Crashcourse Waterstof (in Dutch) by Sieb at Koperloper Nederland Waterstofland event!
From 6:00 minutes and onwards, Sieb will explain everything. Enjoy!