Basin Electric Power Cooperative has taken another step toward what it envisions as one of the world’s largest carbon capture demonstration projects.

Among six contenders, the CO₂ capture technology developed by Powerspan Corp., ECO₂ ®, was selected by the cooperative for a commercial-scale demonstration at a 900 MW coal-based electrical generation facility near Beulah, North Dakota.

Leading models for reducing greenhouse gas emissions all include carbon capture and storage (CCS) technology as a critical piece of the puzzle; however, the technology is still in its infancy and has yet to be proven viable on a commercial scale. This demonstration will allow Basin Electric and Powerspan to verify tests in which 90 percent of the carbon dioxide from flue gas was successfully captured and reprocessed using an ammonia solution.

Approximately one million tons of CO₂ will be captured annually from an equivalent 120 megawatt slipstream project from one of the plants generating units, making this demonstration among the largest in the world. The captured CO₂ will be fed into the existing CO₂ compression and pipeline system for oil recovery owned by Basin Electric’s wholly owned subsidiary, Dakota Gasification Company.

Ron Harper, CEO and general manager of Basin Electric Power, said the promise of the new capture technology is essential at a time when generation and reduced emissions are major issues.

“That’s why we are exploring a project that could lead to commercialization of carbon capture technology for existing coal-based generation facilities.”

The project at Basin Electric’s Antelope Valley Station will provide important information, including:

• modifications necessary to retrofit existing coal-burning power plants with CCS technology;
• the additional energy needed to capture and compress the carbon dioxide for transportation and storage (Powerspan estimates the process will boost the energy requirements by 15 percent);
• the actual percentage of CO₂ that can be captured from the flue gas using this process (Powerspan estimates 90 percent can be captured).

Powerspan’s CO₂ capture process was selected as the most promising low-cost option for commercial deployment and for its ability to best integrate with Basin Electric’s operations.

About the capture technology

Powerspan’s CO₂ capture process, called "ECO₂" is a post-combustion, regenerative process, which uses an ammonia-based solution to capture CO₂ from the flue gas of a power plant and release it in a form that is ready for further compression, safe transportation, and geological storage.

The CO₂ capture takes place after the nitrogen oxides (NOx), sulfur dioxide (SO₂), mercury and fine particulate matter are captured. Once the CO₂ is captured, the ammonia-based solution is regenerated to release CO₂ and ammonia. The ammonia is recovered and sent back to the scrubbing process, and the CO₂ is in a form that is ready for geological storage.

Ammonia is not consumed in the scrubbing process, and no separate by-product is created.

The project is scheduled to move forward in 2009, subject to the completion of engineering studies and any necessary permits. While the design of the commercial demonstration unit is yet to be finalized, the facility is expected to be operational in 2011.