Basin Electric Power Cooperative will achieve an international milestone when it constructs technology at its Beulah power plant to capture carbon dioxide before it leaves the emission stack.

Thursday, Basin announced it had selected a New Hampshire company, Powerspan Corp., from six companies that proposed to design and build a commercial demonstration project at Antelope Valley Station.

The process, with a $200 million price tag, should capture 1 million tons of C02 annually, and Basin will add it to the compressed carbon gas it pipes from its adjacent synthetic natural gas plant, to Canada, where it enhances oil recovery and is permanently stored underground.

Basin said it chose Powerspan for its low cost and for the design ability to integrate with Basin's operations.

Construction should start in 2009 if engineering, permitting and Department of Energy incentives, or tax credits, for carbon capture can be obtained by then.

The process will capture carbon by diverting, or "slipstreaming," 120 megawatts of combustion from Unit 1, making it among the largest such demonstrations in the world. Unit 1 has capacity to generate 450 megawatts of electricity.

Powerspan's process utilizes an ammonia-based solution to capture carbon gas from the flue gas. The ammonia is recovered and recycled.

Basin's general manager Ron Harper said the project will prove a technology that can be retrofitted to the hundreds of coal-based power plants in the country.

"… we're ready to move to the next level," he said.

Powerspan's chief executive Frank Alix said the information learned at Antelope Valley will lead to design and construction of full-scale carbon capture systems.

That information will be critical if Congress ever requires carbon capture for new or existing coal-fired plants as it appears it will.

The gas is a so-called greenhouse gas and said to contribute to global warming.

Basin Electric's wholly owned subsidiary, Dakota Gasification Co., is the only company in the U.S. that captures CO2 from coal and delivers it for enhanced oil recovery operations. DGC has been delivering the carbon gas since 2000.

That experience makes Basin well prepared to move forward on the power plant demonstration project, Harper said.

Powerspan Corp., based in Portsmouth, N.H., develops and commercializes proprietary multi-pollutant control technology for the electric power industry.