Direct air capture 'unlikely' to address CO2 concerns

‘We humans should not kid ourselves that we can pour all the CO₂ we wish into the atmosphere right now and pull it out later at little cost,’ said Robert Socolow, a professor of mechanical and aerospace engineering at Princeton University.

The report — Direct Air Capture of CO₂ with Chemicals — was issued by a committee of 13 experts co-chaired by Socolow and Michael Desmond, a chemist at BP.

The group looked at technologies, known as DAC, in which ambient air flows over a chemical sorbent that selectively removes the CO₂. The CO₂ is then released as a concentrated stream for disposal or reuse, while the sorbent is regenerated and the CO₂-depleted air is returned to the atmosphere.

In essence, the committee found that such technologies would be far more expensive than simply preventing the emission of the CO₂ in the first place.

Making optimistic assumptions about initial DAC technologies, the committee concluded that, from the evidence it had seen, building and operating a system today would cost at least $600 (£367) for each metric ton of CO₂ removed from the atmosphere. In comparison, removing CO₂ from the flue gas of a coal-fired power plant would cost about $80 per ton.