Basic information on hydroge

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Why hydrogen?
The basic precondition for the application of hydrogen in all sectors concerned is the transition to a low-emission or zero-emission economy. As for the constant efforts of states across all continents, new alternatives for the development of climate-neutral technologies are sought. The European Union itself has set the goal of achieving complete climate neutrality for the year 2050, i.e., capturing and storing the same amount of greenhouse gas emissions as will be released into the atmosphere. The very fact of the development of renewable energy sources across the Member States then creates room for stabilizing their unpredictable electricity production. In this case, hydrogen will play the role of an energy carrier, which is especially suitable for seasonal accumulation and some mobility applications.
What is hydrogen?
Hydrogen is the lightest gaseous chemical element forming up two-thirds of the entire cosmic mass. It is estimated that it makes up more than 30% of the total mass of the Sun. It is the third most widespread element on Earth, yet it occurs almost never as a single molecule because it is highly reactive and forms compounds immediately. Hydrogen is ubiquitous, whether in the form of water, natural gas, or methanol. As the simplest and lightest element, it disperses into the air very quickly when escapes. When escaping, hydrogen does not pollute the environment in any way. It is an emission-free substance that is non-toxic and odourless. Hydrogen is a combustible element, but it does not support combustion, and burns with a pale blue flame.
What is the history of hydrogen use?
Hydrogen is a long-known gas in the world, discovered in 1776 by the British scientist Henry Cavendish. Unfortunately, hydrogen was not widely used in industry at the time of its discovery, mainly due to the advent of cheaper fossil fuels in the 19th and 20th centuries. When pronouncing the word 'hydrogen', everyone will remember the Hindenburg airship disaster. Although "banging" hydrogen is still blamed, the catastrophe was caused by an electric shock that ignited the highly flammable material from which the hull was made. To this day, the terrifying video of the burning airship raises concerns and creates a stigma over the various applications of hydrogen. The expansion of hydrogen use was due to space research missions in the 1960s, such as the Apollo missions. Hydrogen was used at that time primarily as fuel for space rockets. In addition, during the Apollo spaceflight, hydrogen fuel cell technology was used on board to generate electricity, heat and water. In the Czech Republic, hydrogen was used as one of the main components of the well-known flue gas, which was later replaced by natural gas.
What energy properties does hydrogen have?
Vodík je energeticky velmi bohaté palivo (33 kWh/kg) a jedná se tak v současnosti o přímého konkurenta zejména bateriovým technologiím.
What is the use of hydrogen?
Hydrogen is a carrier (storage) of energy. It is widely used in transport, energetics and other industries. In the future, hydrogen is to serve as one of the energy carriers for the application of the so-called sector coupling, or the concept of sector integration.
How is hydrogen produced?
96% of all hydrogen produced today comes from fossil fuels. Only 4% is produced by water electrolysis. However, this ratio should change in the next decade in favour of emission-free production by means of the above-mentioned electrolysis of water.
How is hydrogen produced in the Czech Republic and what is the potential for the production of green hydrogen in our country?
Due to its specific position in the heart of Europe, the Czech Republic has relatively little potential for the production of so-called green hydrogen. The utilization coefficient (approximately slightly above 20%) of wind power plants is lower in our country than in neighboring coastal states, where strong and stable winds (approximately above 30%) blow over sea coasts. At present, there is no large electrolyser in the Czech Republic designed for the production of green hydrogen on a commercial basis. A small electrolyser using solar energy with an output of 6 kW is located in ÚJV Řež and is intended only for research purposes. Nevertheless, large electrolysers exist in the Czech Republic, but they are used primarily for the production of other chemicals and the so-called white hydrogen is formed here only as a by-product. It is worth to mention the largest Czech electrolyser, which is operated by Spolchemie for the production of chlorine. As a by-product, hydrogen is also produced there, the use of which is considered for urban transport in cooperation with the town of Ústí nad Labem in the future. Most hydrogen in the Czech Republic is produced by the Unipetrol company that by means of partial oxidation of heavy oil residues, steam reforming and from the ethylene unit produces more than 85,000 tons of hydrogen per year, which is then used mainly for the production of ammonia.
What is water electrolysis?

Elektrolýza je proces, při kterém stejnosměrný elektrický proud štěpí chemickou vazbu mezi vodíkem a kyslíkem ve vodném roztoku.

2 H2O → 2 H2 + O2

What types of electrolysers do we have?
At present, there is talk of a total of three types of electrolyzers, which are advanced enough to saturate market demand. These are electrolysers using alkaline electrolysis, PEM electrolysis and high-temperature electrolysis taking place in solid oxide fuel cells.
How much water is used in electrolysis?

To produce 1 kg of hydrogen and 8 kg of oxygen, 8.92 liters of demineralized water are needed, i.e., water free from all minerals present (even purer than distilled water).

What water can be used for electrolysis?
The water needed to produce very pure hydrogen must be demineralized, i.e. free of all solutes and impurities. However, it can be obtained from virtually any water source.

Hydrogen storage

How is it possible to store hydrogen?
At present, the compression of hydrogen in the gaseous state is mentioned as the most promising and also as the most commercially advanced technology for hydrogen storage. The hydrogen thus stored tends to escape due to the very small size of molecule. Modern storage tanks are already made of extremely strong and airtight materials, allowing safe storage with minimal losses of stored hydrogen. Compared to the competitive possibilities of hydrogen storage, the compression of hydrogen gas clearly has the least

Hydrogen applications in mobility

What are fuel cells?
Fuel cells in electric cars are basically small electricity generators obtaining energy from a direct electrochemical reaction between oxygen and hydrogen. Hydrogen is stored in a tank from which it is fed to the fuel cell. There it reacts with oxygen to produce electricity. The product of this electrochemical reaction is only distilled water.
How do fuel cells work in electric cars?

The fuel cell is similar in construction to batteries. In the fuel cell we find the anode, cathode and membrane with a catalyst. Hydrogen enters the system on the anode side and oxygen on the cathode side. Hydrogen is decomposed into an electron at the anode and an hydrogen proton, which is transported by the membrane to the cathode, reacts there with the oxygen present. The product is only distilled water and electricity, in addition, unused oxygen leaves the fuel cell.

How is a battery electric car different from a fuel cell one?
A fuel cell vehicle (FCEV) is also an electric vehicle. The car includes a battery, electric motor and fuel cell along with a hydrogen tank.
How is a hydrogen electric car refueled?

Refueling takes place at filling stations. The whole process is very similar to refueling traditional fossil fuels. After connecting the filling gun to the tank valve, you press the lever and the whole system will take care of the rest of the work. Filling the tanks takes 5 minutes and gives the car full capacity.

How many filling stations do we have in the Czech Republic?
At present, no public access to the filling station in the Czech Republic is open. One filling station, which is used mainly for research purposes, is located in Neratovice. However, a total of three are being prepared for 2021, which will be managed by the Unipetrol company – in Litvínov, Prague and Brno.
How does a hydrogen electric car work in cold weather?

The advantage is the reliability of the whole system in cold weather. Compared to battery packs, fuel cells are not subject to degradation during cold weather.

Can't the wastewater in the hydrogen electric car system freeze?
Fuel cell systems and water drainage are currently designed so that water cannot freeze throughout the car system.
Is battery electromobility a better transport solution than fuel cells?

It depends on who you ask and what type of transport we are talking about. However, hydrogen and batteries should be two complementary technologies that will complement each other. Why?

How heavy are hydrogen storage tanks in cars?
With the hypothetical storage of 4.2 kg of compressed hydrogen at a pressure of 700 bar, we need a tank in cars weighing about 135 kg. The tanks are currently made of reinforced carbon fibre.
Couldn't hydrogen be liquefied and then refueled like standard petrol?

This solution is extremely energy inefficient. Liquid hydrogen needs to be maintained at -253 °C and if such conditions are not met, hydrogen will evaporate.

Is hydrogen safe?

All fuels contain a high concentration of energy and can therefore be dangerous under certain conditions. However, hydrogen can be considered as similarly safe or even safer than any other fuel. In addition to standard crash tests, hydrogen tanks are also tested to withstand firing from a sniper rifle. The tanks can withstand twice the pressure that will be achieved under standard conditions. Filling stations, which have a number of systems focusing on safety when working with high pressure, are similarly safe.

The advantage in the safety of the use of hydrogen is also its very low density, when hydrogen rises rapidly when the tank is punctured, therefore it does not accumulate near the accident. In the event of fire, a flame will be created, which will rise vertically upwards and the vehicle will not fire as it is in case of liquid fossil fuels.

Hydrogen economy

How much does it cost to produce 1 kg of hydrogen?

The price depends mainly on the method of production. In addition, for the production of green hydrogen, it is necessary to take into account the different price in different parts of the world, depending on how much it costs to produce electricity from renewable energy sources. According to the International Energy Agency, the price of hydrogen production is as follows:

Steam reforming of natural gas $ 1–3.5/kg

Coal gasification $ 1.2–2.2/kg

Water electrolysis $ 3–7.5/kg

How much does 1 kg of hydrogen cost at filling stations?

For the end user, the price of hydrogen per kg is currently set at 9.5 euros in Germany (where most filling stations are located). Converted to kilometers and with an average consumption of 1 kg per 100 km, 1 km in a hydrogen electric car will cost you ~ 0,094 EUR.

How will the price reduction be achieved in the next 10 years?

The hydrogen economy will not be sufficiently developed without the help of state subsidies. In order to reduce the price, it is necessary to invest in production. In the coming years, support for low-emission and zero-emission (green hydrogen) will prevail in Europe, with the aim of building 40 GW electrolysers within the EU by 2030 and supporting the construction of another 40 GW electrolysers across borders to increase imports. In addition to increasing production capacity, the price of green hydrogen will also be reduced by technological progress and increasing the efficiency of the electrolysers themselves.

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Project "Coordination activity of the Czech Hydrogen Technology Platform 2027"
CZ.01.01.01/07/24_052/0005624
is Co-funded by the European Union.