Carbon Dioxide – Geologic Sequestration | Climate Change – Greenhouse Gas Emissions | U.S. EPA
July 3, 2011 Leave a comment
Mississippians are told by their Elected Public Service Commissioners that the Kemper County Coal Plant will Capture CO2 then store, transport, and trade it. So let’s learn more about this process:
According to scientists, atmospheric build-up of carbon dioxide (CO2) and other greenhouse gases as a result of human activities is changing the composition of the Earth’s atmosphere and tending to warm the planet. Scientific studies link these changes to shrinking glaciers, sea level rise, changes in plant and animal habitats, and other global impacts. One possible way to avoid the negative impacts of higher atmospheric concentrations of CO2 is to avoid emitting the CO2 into the air in the first place.
Carbon dioxide can be captured at stationary sources and injected underground for long-term storage in a process called geologic sequestration (GS) (Video – WMV, 8 min.). In its Special Report on Carbon Dioxide Capture and Storage Exit EPA Disclaimer, the Intergovernmental Panel on Climate Change (IPCC) identified CO2 capture and geologic sequestration as one of several options (including energy efficiency and renewable energy) that have the potential to reduce climate change mitigation costs and increase flexibility in achieving greenhouse gas emission reductions. The IPCC estimates that there is enough capacity worldwide to permanently store as much as 1,100 gigatons of CO2 underground (for reference, worldwide emissions of CO2 from large stationary sources is approximately 13 gigatons per year) (IPCC, 2005).
Confidence in this technology is supported by the knowledge that CO2 produced through natural processes has been retained in geologic formations for hundreds of millions of years (IPCC, 2005). The presence of multiple trapping mechanisms will reduce the mobility of CO2 underground over time, decreasing the risk of CO2 leaking to the surface (IPCC, 2005). It is likely that well-selected, well-designed, and well-managed GS sites can sequester CO2 for long periods of time.
Approximately 95% of the largest stationary sources of CO2 emissions (e.g., coal-fired power plants) in the United States are within 50 miles of a candidate GS site (GTSP, 2006). Considering the large storage capacity in the United States, GS has the potential to contribute significantly toward meeting the goals of the nation’s climate policy. To help realize these goals, the federal government is conducting a wide range of GS-related activities.
EPA Roles and Responsibilities
EPA’s goal is to ensure that GS activities are conducted safely and effectively. EPA’s Underground Injection Control (UIC) program regulates underground injection of CO2 and other fluids under the Safe Drinking Water Act (SDWA). The UIC regulations were designed to help ensure that injected fluids do not endanger underground sources of drinking water. The regulations are implemented by state and federal regulators and well operators with expertise in relevant geological issues, well siting, well construction, well operation, and well closure. With over 800,000 regulated wells injecting a variety of fluids over the past 30 years, the UIC program is one of the largest and most experienced permit programs in the nation.
EPA’s primary responsibilities include:
Developing Greenhouse Gas Reporting Mechanisms for GS Under the Clean Air Act
Developing UIC Regulations Under the Safe Drinking Water Act (SDWA)
Evaluating Risks to Human Health and the Environment
EPA is working closely with the Department of Energy (DOE), state co-regulators and other stakeholders on all GS activities to leverage resources, clarify key questions and data gaps, and ensure that work is complementary and not duplicative. The following are examples of the products of these coordinated efforts:
EPA issued Class V Experimental Technology Well Guidance for Pilot Geologic Sequestration Projects in March, 2007 to assist in processing permit applications for near-term pilot projects.
EPA has been sponsoring and co-sponsoring workshops on Geologic Sequestration since 2005.
EPA’s GS-related activities support those that DOE is conducting. For more than a decade, DOE has led federal efforts on research, development, and deployment of GS technologies. DOE is currently directing seven regional carbon sequestration partnerships and overseeing the development of FutureGen Clean Coal Projects, an initiative to equip multiple new clean coal power plants with carbon capture and storage technology.
GTSP. 2006. Carbon Dioxide Capture and Geologic Storage: A Core Element of A Global Energy Technology Strategy to Address Climate Change. Global Energy Technology Strategy Program.
IPCC. 2005. Special Report on Carbon Dioxide Capture and Storage, Special Report of the Intergovernmental Panel on Climate Change.