Direct air capture technologies vie for pre-eminence

Capture and storage of CO₂ is attracting interest from non-energy corporations seeking to achieve net-zero emissions

Direct air capture (DAC) plants all seek to offer a relatively inexpensive means of cutting net greenhouse gas to companies in hard-to-abate sectors such as aviation—but two rival technologies are battling for dominance in the nascent sector. DAC plants are usually proposed above sequestration sites, where captured CO2 is stored underground, eliminating the need for costly pipelines. Fifteen small-scale DAC plants are operational worldwide capturing around 9,000t of CO2 annually, according to an IEA report last June. There are two competing DAC technologies—liquid and solid. Canada’s Carbon Engineering uses a hydroxide solution to capture, purify and condense CO2, while Switzerland’s Climewo