As part of its climate change commitments in the aftermath of signing the historic Paris agreement India is now exploring the possibility of carbon capture utilization storage or CCUS.
A high-level Indian delegation attended an international meeting in Alabama looking into the possibility of adaptation of CCUS, which is the process of capturing waste carbon dioxide (CO2) from large point sources, such as fossil fuel power plants, transporting it to a storage site, and depositing it where it will not enter the atmosphere, normally an underground geological formation.
The three-day conference, which attracted attendees from around the world, was attended by Dr Prabhat Ranjan, Executive Director of TIFAC — Technology Information Forecast and Assessment Council — of Department of Science and Technology and Dr S K Acahrya, Chairman of Neyveli Lignite Corporation.
CCUS is a process that captures carbon dioxide emissions from sources like coal-fired power plants and either reuses or stores it so it will not enter the atmosphere.
Carbon capture and storage (CCS) (or carbon capture and sequestration or carbon control and sequestration) is the process of capturing waste carbon dioxide (CO2) from large point sources, such as fossil fuel power plants, transporting it to a storage site, and depositing it where it will not enter the atmosphere, normally an underground geological formation.
The aim is to prevent the release of large quantities of CO2 into the atmosphere (from fossil fuel use in power generation and other industries).
It is a potential means of mitigating the contribution of fossil fuel emissions to global warming and ocean acidification.
Although CO2 has been injected into geological formations for several decades for various purposes, including enhanced oil recovery, the long term storage of CO2 is a relatively new concept.
The first commercial example was the Weyburn-Midale Carbon Dioxide Project in 2000. Other examples include SaskPower’s Boundary Dam and Mississippi Power’s Kemper Project. ‘CCS’ can also be used to describe the scrubbing of CO2 from ambient air as a climate engineering technique.
There are three main techniques: the post-combustion process involves scrubbing the power plant’s exhaust gas using chemicals.
Pre-combustion CCS takes place before the fuel is placed in the furnace by first converting coal into a clean-burning gas and stripping out the CO2 released by the process. The third method, oxyfuel, burns the coal in an atmosphere with a higher concentration of pure oxygen, resulting in an exhaust gas that is almost pure CO2.
Once the CO2 has been trapped, it is liquefied, transported – sometimes for several hundred miles – and buried, either in suitable geological formations, deep underground saline aquifers or disused oil fields.
The last method is often used in a process called “enhanced oil recovery”, where CO2 is pumped into an oil field to force out the remaining pockets of oil that would otherwise prove difficult to extract.