Scientists from the University of Cambridge in the UK have developed a reactor that captures carbon dioxide (CO2) directly from the air and converts it into syngas using sunlight as the power source.
A form of direct air capture (DAC), the scientists say that the process could be used to make fuel to power cars and planes, or chemicals and pharmaceutical products, without relying on fossil fuels.
The reactor offers an alternative approach to CO2 management, as carbon capture and storage (CCS) remains energy-intensive and faces long-term storage challenges. While CCS is getting lots of funding from governments around the world, its viability and safety remain topics of debate.
Professor Erwin Reisner, who led the research, argued in releasing the findings that CCS alone is not a long-term solution, as it is in the fossil fuel value chain – “which is what caused the climate crisis in the first place.”
Reisner added that CCS is part of a non-circular process, since the pressurised CO2 is, at best, stored underground indefinitely, where it’s of no functional use.
The team’s system makes use of CO2 by capturing it and turning it into syngas – a mixture of hydrogen and carbon monoxide used in the production of hydrocarbon fuels and industrial chemicals like ammonia.
Inspired by photosynthesis, the solar-powered flow reactor captures CO2 at night using specialised filters and converts it into syngas using sunlight when the sun comes up. The device absorbs CO2 like a sponge, releasing it when heated by the sun, while a semiconductor powder drives the chemical reaction that turns the CO2 into fuel. A mirror on the reactor concentrates the sunlight, making the process more efficient.
“If we made these devices at scale, they could solve two problems at once: removing CO2 from the atmosphere and creating a clean alternative to fossil fuels,” said Dr Sayan Kar from Cambridge’s Yusuf Hamied Department of Chemistry.
If scaled up, the researchers said their reactor could be used in decentralised energy production, allowing individuals to generate their own fuel, particularly in remote or off-grid locations.
“Instead of continuing to dig up and burn fossil fuels to produce the products we have come to rely on, we can get all the CO2 we need directly from the air and reuse it,” said Reisner.
