Direct Air Capture (DAC)

Direct air capture (DAC) extracts CO2 from ambient air, which holds it at roughly 420 ppm, using sorbent or solvent contactors, then concentrates it for storage or use. The dilute feed makes DAC energy-intensive: roughly 1,500 to 2,000 kWh of heat and power per tonne CO2, far above point-source capture from a 4 to 12% exhaust stream. DAC is not an onboard ship technology; in shipping it appears as a shore-side route to engineered carbon removal or to synthetic e-fuel feedstock, and as a source of carbon-removal credits used in offsetting.