Are hydrogen planes the future? – Apparatus

An average of 1,066 flights depart from Schiphol every day. Every air journey has a burden on the environment 7 to 11 times as much as the same journey by train. The impact on the environment is greatest at a short distance of travel. ‘Short’ refers to distances of less than 700 kilometres. If you compare flying with a car, a flight per kilometer is 2 to 4 times more harmful to the environment. Worldwide, aviation is responsible for approximately 3 percent of emissions.

To combat climate change, alternative fuels for aircraft are being sought. Green hydrogen is a sustainable alternative to flying on kerosene fuel. No CO₂ is released when hydrogen is burned. Are hydrogen-powered aircraft the future?

What is Hydrogen?

Hydrogen – also known as H₂ – is a flammable gas that, except for the experimental white hydrogen, cannot be extracted from the ground.

There are three different ways to make hydrogen: green, gray and blue.

Green hydrogen

When producing green hydrogen, electricity is used to split water (electrolysis). The splitting takes place in a so-called electrochemical cell. During this electrical process of making hydrogen, no CO₂ is released.

The source of electricity for this way of making hydrogen is green electricity. Electricity from sustainable sources such as sun, wind or hydropower. The current ensures that water can be converted into hydrogen and oxygen. This process is called electrolysis. Currently, only 1% of all hydrogen is green hydrogen.

Gray hydrogen

Gray hydrogen is produced using oil, gas or coal. Take natural gas, for example: heating and pressurizing causes a chemical reaction to take place. This reaction releases hydrogen and CO₂. A major disadvantage of gray hydrogen is the number of kilos of CO₂ that is released during production: no less than 7 kilos per kilo of hydrogen. In the Netherlands, 99% of all hydrogen is grey.

Blue hydrogen

When producing blue hydrogen, the CO₂ released during the process is captured and stored underground. Blue hydrogen has not yet been produced on a large scale anywhere in the world.

Hydrogen is cleaner, but also more dangerous

At the moment there are already cars on the market that run on hydrogen. A hydrogen car is fully electric and is powered by one or more electric motors. The hydrogen supplies electricity via a fuel cell that converts hydrogen into water and electricity. This electricity is needed for the electric motors that move the car.

Unfortunately, until now there is no properly functioning hydrogen engine especially for jet aircraft, such as large passenger aircraft. One of the biggest challenges of hydrogen as a fuel for aircraft is the instability of the flame when ignited. This instability can lead to dangerous situations such as an explosion. For a suitable solution, a lot of physics and mathematics are involved. Aircraft will have to take on a completely different shape than we are currently used to, because hydrogen takes up much more space per kilo than kerosene.

Successful test flight on hydrogen

The largest hydrogen aircraft in the world, financed by the British government, has completed a successful first test flight of just under ten minutes. During this test you can clearly see how the take-off and landing work exactly. In the video below we show the first flight of the ZeroAvia Dornier228.

Do green passenger planes have the future?

ZeroAvia has faith in the green (or blue, depending on how you look at it) passenger planes that can fly entirely on hydrogen. For example, the objective is to put the first hydrogen aircraft into service in 2025. It is expected that at least 550 kilometers can be covered. So another 2 years of waiting.