TECHNOLOGIES FOR CARBON CAPTURE AND STORAGE

Technologies for Carbon Capture and Storage

Technologies for Carbon Capture and Storage

Carbon capture and storage (CCS) is a means of mitigating the contribution of fossil fuel emissions to global warming, based on capturing carbon dioxide (CO2) from large point sources such as fossil fuel power plants, and store it away from atmosphere by different means. It can also be used to describe the scrubbing of CO2 from ambient air as a geoengineering technique.

The term carbon dioxide capture and storage has also been used to describe biological techniques such as biochar burial, which use trees, plankton, etc. to capture CO2 from the air. However, it is more conventional to use the term carbon capture and storage to describe non-biological processes of capturing carbon dioxide from combustion at the source.

Although CO2 has been injected into geological formations for various purposes, the long term storage of CO2 is a relatively new concept. The first commercial example is Weyburn in 2000; integrated pilot-scale CCS power plant was to begin operating in September 2008 in the eastern German power plant Schwarze Pumpe run by utility Vattenfall, in the hope of answering questions about technological feasibility and economic efficiency.

CCS applied to a modern conventional power plant could reduce CO2 emissions to the atmosphere by approximately 80-90% compared to a plant without CCS. The IPCC estimates that the economic potential of CCS could be between 10% and 55% of the total carbon mitigation effort until year 2100 (Section 8.3.3 of IPCC report.)

Capturing and compressing CO2 requires much energy and would increase the fuel needs of a coal-fired plant with CCS by 25%-40%. These and other system costs are estimated to increase the cost of energy from a new power plant with CCS by 21-91%. These estimates apply to purpose-built plants near a storage location: applying the technology to preexisting plants or plants far from a storage location will be more expensive. However, recent industry reports suggest that with successful research, development and deployment (RD&D), sequestered coal-based electricity generation in 2025 will cost less than unsequestered coal-based electricity generation today.

Storage of the CO2 is envisaged either in deep geological formations, in deep ocean masses, or in the form of mineral carbonates. In the case of deep ocean storage, there is a risk of greatly increasing the problem of ocean acidification, a problem that also stems from the excess of carbon dioxide already in the atmosphere and oceans. Geological formations are currently considered the most promising sequestration sites. In its 2007 Carbon Sequestration Atlas, the National Energy Technology Laboratory (NETL) reported that North America has enough storage capacity at its current rate of production for more than 900 years worth of carbon dioxide. A general problem is that long term predictions about submarine or underground storage security are very difficult and uncertain and CO2 might leak from the storage into the atmosphere.

When applied on plants which use biomass, the process is known as bio-energy with carbon capture and ...