Washington, September 30 : Scientists have shown that it is possible to reduce carbon dioxide (CO2) using a relatively simple machine that can capture the trace amount of CO2 present in the air at any place on the planet.
The machine has been developed by a team of researchers from the University of Calgary (U of C) in Canada, lead by climate change scientist David Keith.
"At first thought, capturing CO2 from the air where it's at a concentration of 0.04 per cent seems absurd, when we are just starting to do cost-effective capture at power plants where CO2 produced is at a concentration of more than 10 per cent," said Keith, Canada Research Chair in Energy and Environment.
"But, the thermodynamics suggests that air capture might only be a bit harder than capturing CO2 from power plants. We are trying to turn that theory into engineering reality," he added.
The research is significant because air capture technology is the only way to capture CO2 emissions from transportation sources such as vehicles and airplanes.
Keith and his team showed they could capture CO2 directly from the air with less than 100 kilowatt-hours of electricity per tonne of carbon dioxide.
Their custom-built tower was able to capture the equivalent of about 20 tonnes per year of CO2 on a single square metre of scrubbing material - the average amount of emissions that one person produces each year in the North American-wide economy.
"This means that if you used electricity from a coal-fired power plant, for every unit of electricity you used to operate the capture machine, you'd be capturing 10 times as much CO2 as the power plant emitted making that much electricity," Keith said.
The U of C team has devised a new way to apply a chemical process derived from the pulp and paper industry cut the energy cost of air capture in half, and has filed two provisional patents on their end-to-end air capture system.
The technology is still in its early stage, Keith said.
"It now looks like we could capture CO2 from the air with an energy demand comparable to that needed for CO2 capture from conventional power plants, although costs will certainly be higher and there are many pitfalls along the path to commercialization," said Keith.
Nevertheless, the relatively simple, reliable and scalable technology that Keith and his team developed opens the door to building a commercial-scale plant.