Photo: Pixabay/stux

Take plastic waste and CO2, then convert them into sustainable fuel by the help of a solar-powered reactor. This may sound too good to be true, but it isn’t.

Scientists at the University of Cambridge have done just this by converting CO2 into syngas, a key building block for sustainable liquid fuels. With this same process they also converted plastic bottles into glycolic acid, which is widely used in the cosmetics industry.

The plastic component is an important trick to this system,” says Motiar Rahaman, a researcher behind a study on the project. “Capturing and using CO2 from the air makes the chemistry more difficult. But, if we add plastic waste to the system, the plastic donates electrons to the CO2. The plastic breaks down to glycolic acid and the CO2 is converted into syngas,” the scientist says.

The researchers have adapted their solar-powered technology so that it works with flue gas or directly from the air, converting CO2 and plastics into fuel and other useful chemicals. Their system contains a photocathode and an anode with two compartments. On one side is captured CO2 solution that gets converted into syngas; on the other side plastics are converted into useful chemicals using only sunlight.

While the technology needs further fine-tuning before it can be used at an industrial scale, the results “represent another important step toward the production of clean fuels to power the economy, without the need for environmentally destructive oil and gas extraction,” the experts say.

Although their solar-driven experiments have used pure, concentrated CO2 from a cylinder, the hope is that in future CO2 can be captured from industrial processes or directly from the air.

“We’re not just interested in decarbonisation but de-fossilisation: we need to completely eliminate fossil fuels in order to create a truly circular economy,” says Erwin Reisner, a professor at the university’s Yusuf Hamied Department of Chemistry.

“In the medium term, this technology could help reduce carbon emissions by capturing them from industry and turning them into something useful, but ultimately we need to cut fossil fuels out of the equation entirely and capture CO2 from the air,” he explains.