The Economist takes a look at ways of removing CO2 directly from the air. One such solution comes from Dr Lackner (nothing new to Fat Knowledge readers who have been aware of his technology for 2 years).
A cupboard-sized prototype (pictured) has already shown that the concept will work, and Dr Lackner is a member of a company, Global Research Technologies (GRT), that hopes to commercialise the technology. A machine the size of a standard shipping container, he estimates, could capture one tonne of CO2 a day.What is new is the way that it can be used to profitably extract CO2 from the air right now.
But given that air-capture machines are electrically powered, and generating electricity usually produces carbon-dioxide emissions, do the sums add up? Dr Keith’s prototype captured a tonne of CO2 using 100 kilowatt-hours of electricity. To generate this much power, a coal-fired power station would add around 35kg of carbon dioxide to the atmosphere, or 3.5% of the amount removed by the air-capture machine. Similarly, GRT estimates that when its technology is scaled up, the emissions associated with operating each machine will be less than 5% of the CO2 captured over its lifetime.
By mass, carbon dioxide is in fact the 19th most important commodity chemical in America, according to the Department of Energy. It can be piped into greenhouses to improve plant yields and is used in food processing, water treatment and fire extinguishers, among other things. Forcing CO2 into oil fields can also increase the amount of oil recovered. Air capture could, says Dr Lackner, be a viable way to supply carbon dioxide for industrial uses even at a cost of $200 per tonne, the current cost of the technology.By using it for industrial purposes, the technology can be profitably utilized right now. This will allow the company to get it out in the field and tested while they continue to make improvements to lower the cost. This will expediate the day when this process can remove CO2 from the air for just $30 a ton.
That is far higher than the cost per tonne of carbon dioxide on emissions-trading markets, where the price of permits that entitle their holders to emit a tonne of carbon dioxide recently fell below $10. Only if the cost of air capture falls below the cost of an emissions permit will it be economically attractive; otherwise emitters will find it cheaper to buy the right to pollute. But environmentalists expect emissions-trading markets eventually to price the gas at about $50 a tonne, and Dr Lackner hopes to get the cost of his process down to $30 per tonne in the long run.