​The purpose of CCS is to reduce carbon dioxide level in the atmosphere.
The carbon capture and sequestration process includes the stages of the capture, compression, transportation and storage of carbon dioxide.
Three types of CCS are:
      - Pre-combustion : CO2 capture from gasfied coal synthesis gas
      - Oxy-combustion : fuel burnt with pure oxygen to produce high purity CO2
      - Post-combustion : CO2 capture from the flue gas produced

Key technologies of post-combustion are:
      - Absorption
      - Adsorption
      - Membrane gas separation

Types of membrane are:
      - Rubbery polymer membrane
      - Glassy polymer membrane
      - Facilitated Transport Membrane