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A new British technology that scrubs carbon dioxide from the air and creates synthetic petrol has the potential to mitigate climate change, the IMechE has said.
The institution has long argued for the development of “air capture” technologies in the battle to control CO2 emissions. Now a Teesside firm, Air Fuel Synthesis (AFS), has gone a stage further by developing a system that can not only scrub CO2 from the atmosphere but also create fuel for transport from the captured carbon.
The AFS system works by blowing air into a tower containing a mist of sodium hydroxide which reacts with the carbon dioxide in the air, forming sodium carbonate. Electricity is then passed through the sodium carbonate to release the CO2, which is stored. A dehumidifier in the tower condenses water from the air, and this water is then split into hydrogen and oxygen using an electric current.
The CO2 and hydrogen react together to create syngas, which is then processed to form methanol. This is passed through a gasoline fuel reactor to create petrol.
The fuel produced can be used in any regular petrol tank and, if renewable energy is used to provide the electricity, the process and end product are “completely carbon-neutral”, said the IMechE. Producing fuel sidesteps the problem of how to store the CO2 and also improves the economics of air capture.
The technology has the potential to stabilise CO2 emissions in some sectors where it might otherwise be difficult to capture them, such as aviation.
Dr Tim Fox, head of energy and environment at the IMechE, said producing aviation fuel from the process would be relatively straightforward. “It’s a carbon recycling process. You have, for example, petrol in the car: you burn it, carbon is emitted through the exhaust into the atmosphere, you capture the carbon, and then use it to make fuel. You’ve effectively created a closed loop that has the potential to stabilise emissions in the atmosphere.”
Countries with abundant renewable energy could develop large air-to-fuel plants, added Fox. “This is a first for British engineering and British ingenuity, but the greatest markets could be overseas,” he said.
AFS would now look to develop a more efficient plant producing about a tonne of fuel a day, but the company needs funding. “Ultimately, what they are looking to do is to build a refinery-scale plant making hundreds or thousands of tonnes a day,” he said.
“What’s really exciting about this is that you could build synthetic fuel production industries in places where they’ve got a lot of renewable energy that they currently can’t use, for their own sufficiency in fuel or for another sector such as aviation.” As a model, he suggested the way in which aluminium smelting developed in Iceland because of the abundance of cheap geothermal electricity there.
“I see this innovation as having export market potential,” said Fox. “If we can develop some of these technologies and the know-how here, then we can export it.”