Commercial scale carbon-dioxide capture is the goal of a demonstration project planned for a Texas coal-fired powerplant. In a quarterly report, its owner calls it one of “the largest carbon-capture and sequestration projects in the world” and says it “may be the first to achieve commercial scale from an existing coal-fueled powerplant.”

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NRG Energy Inc., Princeton, N.J., and Powerspan Corp., Portsmouth, N.H., have signed a memorandum of understanding to jointly design, construct and operate a demonstration of Powerspan’s ECO2 technology at NRG’s W.A. Parish powerplant, Thompsons, Texas. The project, whose cost NRG officials have estimated between $150 million and $200 million, will be designed to capture 90% of the carbon dioxide from flue gas equal in quantity to that from a 125-MW unit. Four of Parish’s units, totaling 2,455 MW, are coal-fueled. The other four, totaling 1,190 MW, use natural gas. NRG officials say the captured CO2 will be used in enhanced oil-recovery operations in the Houston area.

Powerspan’s electrocatalytic oxidation (ECO) multipollutant emissions-control process has successfully demonstrated postcombustion removal of oxides of nitrogen, sulfur dioxide, mercury and particulate matter from a 50-MW slipstream of a 157-MW unit at FirstEnergy Corp.’s R.E. Burger plant in Shadyside, Ohio, since 2004 (ENR 10/24/05 p. 13). Powerspan and FirstEnergy now are developing a regenerative ammonia-based process trade-named ECO2 and integrated with the ECO process to capture CO2 equivalent to 1 MW of the slipstream. The companies expect to have it operating in the first quarter of 2008, says Powerspan President Phil Boyle.

NRG and Powerspan will install both the ECO process, minus NOx control, and the ECO2 process on the Parish plant’s slipstream. It operates like a bucket brigade, says Boyle. An ammonia-based solution captures CO2 from flue gas and carries it to a regenerator. The regenerator then heats the solution to release the CO2 and returns it to the absorber to repeat the cycle.

“This demonstration project with Powerspan at one of the largest baseload coal facilities in the country has the potential to be a breakthrough in postcombustion carbon capture,” said NRG President Dav-id Crane, announcing the project.

It is scheduled for operation in 2011.