Carbon capture and storage is a four-step process
- Pure CO2 captured from flue gas or other process stream
- Compressed to ~100 atm (~1500 psi)
- Transported to injection site
- Injected deep underground into geological formations
Developing Key Climate Change Technology
As the nation seeks to address climate change, carbon capture and storage has been widely viewed as one of the major technologies with potential to both reduce greenhouse gases and ensure the continued use of coal — the most abundant fossil fuel — to generate electricity.
Southern Company is playing a leading role in the effort to bring about reliable and cost effective carbon capture and storage technology, with involvement in several major capture/permanent storage research and development projects.
"We are working with our partners on several fronts to advance new carbon capture and storage technology beyond the lab," said Steve Wilson, director of research and technology management.
Pilot-scale carbon capture projects should be operating within the next 12 months, but it will be some time before these are commercially ready for full-scale power plant application, Wilson said.
Much of the research is aimed at helping the industry better understand the performance, reliability and cost, as well as public risks and benefits, of various carbon capture and storage approaches. Current Southern Company carbon capture and storage research includes:
Utility consortium to demonstrate first application of CO2 capture process
A consortium led by the Electric Power Research Institute has partnered with Alstom to demonstrate, at a small 2-megawatt pilot-scale, the first application of a new process to strip CO2 from power plant flue gas. Following construction and start-up, testing will begin on the process in late 2007. Consortium members include Southern Company and more than 25 other utilities.
Plant Daniel hosts regional carbon sequestration partnership demonstration
With partners DOE, EPRI, and the Southern States Energy Board, Mississippi Power’s Plant Daniel is hosting a demonstration under the second phase of the Southeast Carbon Sequestration Regional Partnership of CO2 storage in a deep saline-filled rock formation. Later this year, drilling will begin that will result in a well nearly 10,000 feet deep into which 3,000 tons of CO2 will be injected in 2008. The demonstration includes monitoring of the CO2 once it has been injected. The primary focus of the project is on public acceptance and permitting of such activities.
Partnership plans to demonstrate CO2 capture technology
For the third phase of its DOE-sponsored Regional Carbon Sequestration Partnership Program, Southern Company and its partners applied to the DOE for a large-scale demonstration of CO2 storage. To provide the CO2, a 50-MW-scale demonstration of advanced CO2 capture technology is being proposed. The CO2 will be injected into a deep geologic structure followed by monitoring of long-term stability. The lack of any proven commercial processes for CO2 removal at this scale will require monitoring planned lab and pilot-scale research in order to select the best possible process for this demonstration.
West Alabama coal seam is test site for CO2 injection
As another part of the DOE Regional Carbon Sequestration Partnership, Southern Company is studying the injection of CO2 into an unmineable coal seam near Tuscaloosa, Ala., to monitor the suitability and permanence of these geologic structures for this purpose.
Alabama’s Citronelle oil field to host CO2 storage demonstration
Partnering with the University of Alabama at Birmingham, Southern Company is studying the capacity of the Citronelle oil field in southern Alabama for the purpose of initially enhancing the field’s oil production but also as a CO2 storage site after as much of the oil as possible has been retrieved. The oil field is located near several coal-fired power plants owned by Southern Company.
Utility consortium to demonstrate oxygen-fired combustion for CO2 capture
Through technology developer Babcock and Wilcox, a consortium of utilities, including Southern Company, has agreed to participate in the retrofit of a pilot coal-fired combustor to burn coal with oxygen instead of air. By separating oxygen from air prior to combustion, the resulting power plant flue gas would consist primarily of CO2 and be free of the large volume of nitrogen typically in flue gas. Such an approach might make the flue gas more storage-ready. Testing at the pilot scale will begin in 2008.
Assessing CO2 geologic storage opportunities across the Southeast
In separate studies for states in its service territory, Southern Company has initiated technical assessments of the potential geologic storage sites for power plant CO2, assuming that technically viable ways to capture CO2 can be found.