In today's increasingly environmentally-conscious society, many contemporary technological developments in aviation have the planet's future in mind. One particular area that has seen extensive research is the fuelling of aircraft. For years, hydrogen-powered flight has been considered the next step for environmentally-friendly air travel. However, recent research has also yielded an alternative solution, that involves repurposing waste carbon dioxide.

A scientific breakthrough

Research carried out by chemists at the University of Oxford has found that CO2 can be combusted in a manner that converts it into usable hydrocarbon compounds. According to Popular Mechanics Magazine, this is done by utilizing a complex catalyst in the combustion process.

These usable hydrocarbons can serve several purposes, including conversion into jet fuel. This is a multi-step process, which first sees the CO2 converted to either carbon monoxide or ethanol. After this stage, the conversion to jet fuel can then follow.

The catalyst is created through the process of organic combustion. It consists of iron, manganese, and potassium. Creating iron-based catalysts often consumes large quantities of water. However, organic combustion represents a more efficient 'one-pot synthesis' approach.

First hydrogen commercial flight
You need to have good weather to fly VFR. Photo: Getty Images

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The new catalyst can then be used to add hydrogen to the CO2. This process is similar to the addition of hydrogen atoms to regular fats. The newly hydrogenated fats are more shelf-stable, and thus better-suited to storage at room temperature, such as in a supermarket's ambient department.

Various options explored

The researchers tried and tested a range of different variables during their project. According to Popular Mechanics, they found that:

"Fe–Mn-K catalysts synthesized with carboxylic acids and polycarboxylic acids as fuels showed superior catalytic performances than those prepared using urea and sugar (glucose) and the catalyst prepared without fuel."

The team even experimented with household products such as flour during this process. There are still lots of unknown aspects to demystify in this field. As such, by testing on as wide a range of compounds as possible, the scientists hope that a clearer picture will emerge. In any case, a promising factor is the fact that even the less-efficient processes can save considerable amounts of CO2.

The future of sustainable aviation fuel

If this process could be made widely available, it could ultimately result in 'net zero' emissions for aircraft using such fuel. However, having only reverse-engineered small amounts of CO2 in the lab thus far, there is lots more work to be done before this can be possible.

Airbus Zeroe
There has been much focus on efficient operation since Concorde, including lately Airbus' ZEROe project. Photo: Airbus

Other areas of research into sustainable aviation fuel have also reached milestones in recent months. September 2020 saw the world's first commercial-grade hydrogen-powered flight take place in Bedfordshire. British Airways has since partnered with ZeroAvia, the flight's operator, in an attempt to accelerate the 'hydrogen revolution.'

Airbus also recently revealed its propositions for hydrogen-powered aircraft in years to come. With many of commercial aviation's leading airlines and manufacturers getting behind the drive for such emission-free flights, the hydrogen revolution might just come sooner than we think.

How do you foresee research into sustainable aviation fuel panning out in the coming years? Let us know your thoughts and hopes in the comments!