Aviation industry has sought ways to reduce its global carbon footprint over the past decade, such as purchasing so-called carbon offsets – such as tree planting projects or wind farms – to offset the carbon dioxide emitted by high-flying aircraft. At the same time, airports in San Francisco, Chicago and Los Angeles, along with a dozen in Europe, supply greener aircraft with alternative fuels to help achieve carbon reduction targets.
Now, a team at Oxford University in the United Kingdom has come up with an experimental process that could turn carbon dioxide – a greenhouse gas emitted by all combustion engines – into aircraft fuel. If successful, the process, which uses an iron-based chemical reaction, could lead to “zero net” emissions from aircraft.
The experiment, reported today in the journal Communications about nature, was performed in a laboratory and still needs to be reproduced on a larger scale. But the chemical engineers who designed and completed the process hope it could be a climate game changer.
“Climate change is accelerating and we have huge emissions of carbon dioxide,” says Tiancun Xiao, a senior researcher at the Oxford Department of Chemistry and a paper author. “The hydrocarbon fuel infrastructure is already there. This process could help mitigate climate change and use current carbon infrastructure for sustainable development. “
When fossil fuels such as oil or natural gas burn, their hydrocarbons are converted to carbon dioxide and water and energy are released. This experiment reverses the process of turning carbon dioxide back into a fuel using something called the organic combustion method (CMO). By adding heat (350 degrees Celsius, or 662 degrees Fahrenheit) to citric acid, hydrogen and a catalyst of iron, manganese and potassium to carbon dioxide, the team was able to produce liquid fuel that would run on a jet engine. The experiment was done in a stainless steel reactor and produced only a few grams of the substance.
In the lab, the carbon dioxide came from a container. But the idea for adapting the concept to the real world would be to capture large amounts of greenhouse gases, either from a factory or directly from the air, to remove it from the environment. Carbon dioxide is the most common greenhouse gas that heats the planet and is produced by factories, cars and wood burning, including forest fires and slash-and-burn agriculture. Keeping it out of the atmosphere could help reduce global warming, although the world’s carbon emissions have risen in recent decades and are on track to warm the planet by 2 degrees Celsius by the end of the century.
Xiao and colleagues say the new method would also be cheaper than existing methods that turn hydrogen and water into a fuel, a process called hydrogenation, mainly because it would use less electricity. Xiao plans to set up a jet fuel plant next to a steel or cement plant or a coal-fired power plant and capture its excess carbon dioxide to produce the fuel. The process could also involve aspirating carbon dioxide from the atmosphere, which is called direct air capture. The tricky catalyst is abundant on earth and requires fewer steps than other methods of synthesizing high value-added chemicals, the authors say.
An expert who was not involved in the experiment says the concept looks promising, as long as the authors can figure out how to go from producing tiny amounts of jet fuel in the lab to making larger quantities in a factory. pilot. “This looks different and looks like it might work,” says Joshua Heyne, an associate professor of mechanical and chemical engineering at the University of Dayton. “Scaling is always a problem and there are new surprises when going up larger stairs. But when it comes to a long-term solution, the idea of a circular carbon economy is certainly something that could be the future. “