UK scientists use solar energy to convert plastic and CO2 into sustainable fuels

Experts describe process as a 'game-changer' in the fight against pollution

Scientists have discovered a way to use solar power to tackle plastic pollution by converting rubbish into sustainable fuels. Getty

Scientists have discovered a way of using solar energy to transform plastic waste and greenhouse gases into sustainable fuels.

Researchers from the University of Cambridge have developed a system that converts two waste streams into two products simultaneously.

It is the first time this has been achieved in a solar-powered reactor.

The reactor converts carbon dioxide and plastics into different products that are useful in a range of industries.

Tests of the reactor under normal temperature and pressure conditions showed that the reactor could efficiently convert plastic bottles and CO2 into different carbon-based fuels such as CO, syngas or formate, in addition to glycolic acid.

Syngas is a key building block for sustainable liquid fuels and glycolic acid is widely used in the cosmetics industry.

In the paper, which has been published in the journal Nature Synthesis, the scientists say the system can easily be tuned to produce different products by changing the type of catalyst used in the reactor.

“Converting waste into something useful using solar energy is a major goal of our research,” said Professor Erwin Reisner from the Yusuf Hamied Department of Chemistry, the paper’s senior author.

“Plastic pollution is a huge problem worldwide, and often, many of the plastics we throw into recycling bins are incinerated or end up in landfill.”

Prof Reisner also leads the Cambridge Circular Plastics Centre, which aims to eliminate plastic waste with new thinking with practical measures.

He says other solar-powered recycling technologies hold promise for addressing plastic pollution and for reducing the amount of greenhouse gases in the atmosphere, but they have not been combined in a single process.

“A solar-driven technology that could help to address plastic pollution and greenhouse gases at the same time could be a game-changer in the development of a circular economy,” said Subhajit Bhattacharjee, the paper’s co-first author.

Plastic pollution on the shoreline of the Thames estuary. Getty

“What’s so special about this system is the versatility and tuneability — we’re making fairly simple carbon-based molecules right now, but in future, we could be able to tune the system to make far more complex products, just by changing the catalyst.”

The team have designed different catalysts.

By changing the catalyst, the researchers could then change the end product.

“Generally, carbon dioxide conversion requires a lot of energy, but with our system, basically you just shine a light at it, and it starts converting harmful products into something useful and sustainable,” said co-first author Dr Motiar Rahaman.

“Prior to this system, we didn’t have anything that could make high-value products selectively and efficiently.”

Prof Reisner recently received new funding from the European Research Council to help the development of the solar-powered reactor.

Over the next five years, they hope to further develop the reactor to produce more complex molecules. The researchers say that similar techniques could one day be used to develop an entirely solar-powered recycling plant.

“Developing a circular economy, where we make useful things from waste instead of throwing it into landfill, is vital if we’re going to meaningfully address the climate crisis and protect the natural world,” said Prof Reisner.

“And powering these solutions using the sun means that we’re doing it cleanly and sustainably.”