How do CO2 Capture technologies work?

How do Co2 Capture technologies work?

To capture carbon dioxide (CO2) it is first separated from other gases resulting from combustion or processing. It is then compressed and purified to make it easier to transport and store.
Carbon dioxide resulting from combustion, particularly in the electricity sector, can be captured using one of three systems: 1) In a post-combustion system, the flue gas produced by combustion of the fuel with air only contains a small fraction of CO2. It is captured by injecting the flue gases in a liquid that selectively absorbs the CO2. 2) In a pre-combustion system, the primary fuel is first converted into gas by heating it with steam and air or oxygen. This conversion produces a gas containing mainly hydrogen and CO2, which can be quite easily separated out. 3) Oxyfuel combustion uses pure oxygen to burn the fuel instead of using air which only contains 20% of oxygen and a lot of nitrogen. It results in a gas mixture containing mainly water vapour and CO2. The water vapour is then easily removed from the CO2 by cooling and compressing the gas stream.