The calcium looping cycle for large-scale CO2 capture

The reversible reaction between CaO and CO₂ is an extremely promising method of removing CO₂ from the exhaust of a power station, generating a pure stream of CO₂ ready for geological sequestration. The technology has attracted a great deal of attention recently, owing to a number of its advantages: the relatively small efficiency penalty which it imposes upon a power station (estimated at 6–8 percentage points, including compression of the CO₂); its potential use in large-scale circulating fluidised beds (a mature technology, as opposed to the vastly upscaled solvent scrubbing towers which would be required for amine scrubbing); its excellent opportunity for integration with cement manufacture (potentially decarbonising both industries) and its extremely cheap sorbent (crushed limestone).