Ongoing litigation over EPA rules raises compliance risks and costs. North Carolina utilities, however, benefited from the state’s forward thinking.
Capture and storage tech developments secure coal’s future.
enhanced oil recovery, or for injection and storage (sequestration) in a suitable underground geological formation. In this pilot project, though, the CO 2 was remixed with the treated flue gas, and the entire extracted gas volume reintroduced into the flue gas desulphurization (FGD) outlet transition duct, where it was mixed with the FGD exhaust gas.
Results are encouraging. The pilot performance improved steadily, to the point that stable absorber operation at 100 percent of design flue gas flow was established by April 2009. Overall, the project achieved the vast majority of its research objectives and demonstrated the fundamental viability of CO 2 capture. “The process was able to successfully capture CO 2 while it was integrated with the other air quality control systems that were in place,” Manthey says. “It was able to capture at about a 90-percent rate, so it was a very good first step.”
He adds that in the future, We Energies would consider using CCS as a technology tool for reducing greenhouse-gas emissions—albeit at a significant price. “One challenge that remains is energy consumption, which is a key cost driver,” he says. Another is that since Wisconsin doesn’t have the geological formations for sequestration, the utility would need to make sure there is a transportation system set up to send the CO 2 to a place where it could be stored. “This likely would be a pipeline system, and we would need to look at the cost of doing this,” he adds.
Considering such costs will be part of the purpose of AEP’s validation-scale project in West Virginia.
Phase II: Mountaineer
AEP and Alstom partnered to install the first CCS project designed to capture and store CO 2 at AEP’s 1,300-MW Mountaineer power plant, a pulverized coal-fired facility in New Haven, W.Va. Built in 1980, Mountaineer emits about 8.5 million metric tons of CO 2 a year.
In 2009, the plant was retrofitted with Alstom’s chilled ammonia CO 2 capture technology on a 20-MW slipstream of the plant’s flue gas. It was designed to capture 330 tons of CO 2 per day, and is capable of removing about 100,000 metric tons of carbon emissions annually.
The project began capturing CO 2 on Sept. 1, 2009, and began storing it on October 2 (although the sequestration process officially was launched October 30). The CO 2 was transported from the plant by pipeline to a nearby well, where it was injected into permanent storage in two saline reservoirs 7,800 feet underground.
“It’s still new, of course, but it’s working as anticipated,” reports Melissa McHenry, an AEP spokesperson. “The data that’s collected and analyzed from this project will support efforts to advance CCS technologies to commercial scale and provide information to the public and industry.”
The project will operate for at least 12 months, but possibly longer, in order to help validate the effectiveness of Alstom’s capture technology, as well as the viability of storage in the local geology. “We will continue to monitor the sequestered CO 2 for some time,” McHenry says.
Following the completion of product validation at Mountaineer, AEP plans to