carbon capture, usage and refers to a suite of technologies that enable the mitigation of carbon dioxide (CO2) emissions from large point sources such as power plants, refineries and other industrial facilities, or the removal of existing CO2 from the atmosphere.
CCUS is expected to play a crucial role in meeting global climate targets. Leading organisations including the International Energy Agency (IEA), International Renewable Energy Agency (IRENA), Intergovernmental Panel on Climate Change (IPCC) and Bloomberg New Energy Finance (BNEF) have all produced long-term energy outlooks that rely on a rapid expansion of CCUS in order to limit global temperature rise to 1.5°C.
A CCUS application consists of three stages: capture, transport and storage (or usage) of CO2. The main methods for capturing CO2 are: post-combustion; pre-combustion; and oxy-fuel combustion. Post-combustion technology separates CO2 from the flue gas, by using a chemical solvent for instance, after the fuel is burnt. Pre-combustion methods involve converting the fuel into a gas mixture consisting of hydrogen and CO2 before it is burnt. Once the CO2 is separated, the remaining hydrogen-rich mixture can be used as fuel. Finally, oxy-fuel technology involves burning a fuel with almost pure oxygen to produce CO2 and steam, with the released CO2 subsequently captured.
Post-combustion and oxy-fuel equipment can be fitted to new plants or retrofitted to existing facilities that were originally built without it. Pre-combustion methods require larger modifications to the operation of the facility and are therefore more suitable to new plants.
Currently operational facilities fitted with CCUS can capture around 90% of the CO2 present in flue gas. It is technologically possible to achieve higher capture rates, and research is ongoing to reduce the costs of doing so. CO2 can also be captured directly from the atmosphere by drawing in air using fans and passing it through an environment consisting of solid sorbents or liquid solvents. This practice is more energy intensive and therefore more expensive as CO2 has a much lower concentration in the atmosphere than in flue gas.

S.Amrin Irfath.

University/College name : Jamal Mohamed College.