Air (or flue gas) is pulled across a CO2-selective sorbent that chemically binds carbon dioxide molecules while letting other gases pass through. Once saturated, the sorbent is heated to release pure CO2 for storage or use, and the cycle repeats.
Capture rate ∝ flow rate × (1 − sorbent_load/capacity)
Efficiency = captured / (captured + slipped)
Energy/kgCO2 ↓ as regeneration heat is optimized
- Method — Direct Air Capture pulls dilute CO2 (~420 ppm) from ambient air; Post-Combustion captures concentrated CO2 (~12%) from flue gas, so particle density and capture rate differ.
- Fan / flow rate — how much air/flue gas is pushed through the sorbent bed per second.
- Sorbent capacity — how much CO2 the sorbent bed can hold before it saturates and needs regeneration.
- Regeneration heat — energy applied to release captured CO2; more heat speeds regeneration but costs more energy per kg captured.
Companies like Climeworks and Carbon Engineering operate real DAC plants using this exact sorbent-adsorption/regeneration cycle to remove CO2 permanently from the atmosphere.