Written by: The Proficient Airman, Mubashar Yasin.

I was recently reading an aviation newspaper by Flight training news and came across a few interesting articles – one of these articles is Airbus’s future plans to address carbon emissions. I have created a short summary on what I read in the article and further research to understand this better. Enjoy the read!

Airbus boasts to create a zero-emissions commercial aircraft by 2035. But how will it go about doing this?

Airbus is planning to replace traditional fuel with a promising alternative, hydrogen to power the zero-emission aircraft.

Why hydrogen?

Well, why not? Here are the reasons why:

•  The energy-per-unit mass of hydrogen is three times higher than that of traditional fuel – so it has more energy potential than traditional fuel.
• Zero carbon emissions – Instead of CO2 emissions, water is the most significant by-product.
• Zero NOx emissions – an engine powered with hydrogen fuel cells produces zero NOx emissions or contrails.

As we know it the hot topic in aviation is carbon emissions. Therefore, it is important this be addressed not only to satisfy the environmentalists and aviation critics but more importantly to create a sustainable aviation. It is believed hydrogen will contribute to reduce carbon emissions by up to 50%.

How is hydrogen used for aircraft propulsion?

The first method is to use hydrogen combustion in a gas turbine. So in theory hydrogen would be burnt the same way jet A is combusted in combustion engines.

The second method is using fuel cells to convert hydrogen into electricity to power an engine. This is the method Airbus is adopting.

As of November 2022, Airbus develops a hydrogen-powered fuel cell engine

This is big! Airbus has recently developed a hydrogen-powered fuel cell engine. They will begin ground and flight testing on the altered A380.

The model being used and tested on is the ZEROe demonstrator A380 MSN1. As we know hydrogen has a low energy density – so this will be a major contributing factor to the change in design of the aircrafts adopting hydrogen. For example, the A380 MSN1 carries liquid hydrogen in tanks on the rear end of the aircraft.

What are fuel-cells and how do they work. Please explain?

Fuel cells generate electricity through electrochemical reactions, instead of through combustion reactions (which is seen in traditional fuels).

The most promising fuel cell is called: The Proton Exchange Membrane (PEM) fuel cell. Here, hydrogen is used as fuel to generate electricity.

Fuels cells have been used in the car industry – but they don’t currently meet safety standards to be adopted in aircrafts.

How do they work?

The electrochemical reaction involves two electrodes (anode/cathode) separated by an electrolyte membrane.

• Hydrogen enters via anode – followed by a catalyst reaction (electrons and protons split apart from hydrogen)
• Oxygen enters via cathode
• Positively-charged protons move across to cathode via electrolyte membrane
• Negatively-charged electrons flow out of cell and generate an electric current
• At the cathode: protons and oxygens combine to form water

Is this achievable?

Fuels can be stacked together from one fuel cell to ‘stacks’ onto ‘channels’ of fuel cells. Having hundreds of fuel cells stacked together will achieve scalability and enough power output to fly an aircraft.

Who has Airbus partnered with to push this project forward?

They partnered with Elring Klinger, a leading provider of fuel cells in the automotive industry. As a result of this partnership ‘Aerostack’ was born in 2020 as a joint venture by Klinger and Airbus.

This is by far an interesting venture, and I look forward to what the future brings. Having a zero-emissions aircraft will definitely revolutionise the industry – it will be the beginning of an era with zero emissions in aviation. It will promote sustainable travel – which offers an exciting prospect whilst changing the way we currently think of travel.