Science paving the way towards circular, zero-emission economy

By Federico Citterich

A team of scientists from the University of Cambridge have developed a sunlight-powered technology that converts CO2 and plastic in renewable fuels and other applicable products.

The team, whose study was published in the journal Joule, successfully converted CO2 into syngas, an important component of sustainable fuels, and plastic into glycolic acid, a chemical found in fruit and used in the pharmaceutical industry.

The researchers hope that this innovative technology will help to mitigate global warming and pollution by lowering the levels of atmospheric CO2 and the amount of plastic waste.

Furthermore, the production of renewable fuels from CO2 could help to fight today’s energy crisis and could pave the way towards the development of a circular, zero-emission economy.

CO2 conversion

To reduce the levels of carbon dioxide in the atmosphere, CO2 is normally captured from the air and stored underground. This, however, has unknown long-term effects. 

Accordingly, CO2 conversion techniques have been developed to transform carbon dioxide into other compounds.

Normally, the majority of CO2 conversion techniques use water oxidation as the counter-reaction, an energy-demanding process that requires inputs of energy from different sources to be carried out.

A trick in the system: the plastic component

The Cambridge researchers, however, believe they have found a trick that could significantly meliorate the energy requirements: using plastic instead of water.

Vatican News spoke to two of the researchers, Sayan Kar and Motiar Rahaman, who explained more about the process and its aims.

“The oxidation of plastic allows us to use solar energy as the sole energy source for the entire process, which would not be possible if water was used instead of plastic," explained Motiar Rahaman from the University of Cambridge.

The implications of this are explicit: CO2 can be converted into renewable fuels without exacerbating our carbon footprint.

Towards a circular economy

The team hopes that this technology can be used in the future to develop a circular and zero-emission economy that completely eliminates the use of fossil fuels.

"The goal is to devise a process that can produce renewable fuels from industrial waste, fuels that would then be reused by the industries themselves," explained Sayan Kar from the University of Cambridge.

"The use of fuels in industries inevitably leads to the release of CO2 into the air, but if we could convert this CO2 back into renewable fuel, then we could think about creating a net-zero circular economy," added Kar.

This would also involve the generation of useful products from plastic waste, with the aim of reducing plastic pollution.

A spark of optimism

"The technology is still in its early stages," said Rahaman. “In order to exploit the process on an industrial scale, every component needs to be optimized, including the carbon capture, solar energy absorption, or CO2 conversion mechanisms."

The researchers estimate that it will take at least a decade for the technology to be used at an industrial scale.

"We are currently working to improve the efficiency and speed of the reaction," concluded Kar. "This will undoubtedly take time, but we are confident and very optimistic."