Carbon capture project

Project update

Winter 2008

System Status

The Alstom Chilled Ammonia Carbon Capture Pilot Demonstration Project, located at We Energies’ Pleasant Prairie Power Plant in Kenosha Country, has been in operation since March. During this period, key modifications have been made to the physical system and operating procedures to optimize the prototype. “It is encouraging to note that the problems to date have been minor and associated with the hardware used in supporting the process,” said Scott Patulski, vice president - Fossil Operations, when discussing the daily progress and results of the demonstration project. “The actual capture of CO2, and the process that supports this activity continue to look very promising.”

More on the CO2 Capture Process

To capture the carbon dioxide gas (CO2), the post-combustion project follows three main steps.

1. The flue gas from the power plant is cooled from 135 degrees Fahrenheit to less than 68.
   • Cooling takes place in the chilled-water, heat-exchanger system.
   • The CO2 in the flue gas reacts most effectively with the CO2 removal chemicals at a reduced temperature.

2. The CO2 is separated from other flue gases, as illustrated in the diagram below.
   • Separation occurs in the Absorber when the chilled flue gas, containing CO2, is introduced to an ammonia-containing reagent through a vertical-spray contact.

                   

3. The chilled ammonium carbonate solution is used to capture the CO2.

• In the Absorber, the CO2 is absorbed in the ammonia reagent.
• Once CO2 is absorbed, ammonium bicarbonate is formed in solution.
• The flue gas containing CO2 is re-circulated in the pilot project system. Other flue gases, not containing CO2, are discharged from the Absorber.
• Regulating pressures and temperatures keeps the ammonium bicarbonate dissolved in solution.

The pure CO2 can be extracted from the solution by heating it to 212 degrees Fahrenheit in the CO2 Regenerator. However, the Chilled Ammonia Carbon Capture Project at We Energies’ Pleasant Prairie Power Plant is in operation to demonstrate that CO2 can be captured using this technology. The next pilot project at American Electric Power will demonstrate not only capture, but also storage.

	EPRI funders from Australia, Canada, Denmark, Finland, France, Germany, UK, along with 20 U.S. utilities attended the Sept. update meeting at We Energies.

First Funders’ Meeting Report

Data summaries and project-specific operational experience were shared with funders from around the world at the first update meeting held in early Sept. at We Energies’ Pleasant Prairie Power Plant. The meeting was presented by The Electric Power Research Institute (EPRI), Alstom and We Energies. As the Carbon Capture Demonstration Project continues, more progress meetings will be held with funders to discuss technology and testing results.

A Look Ahead

The next Carbon Capture Project will be six times the size of the We Energies’ Pilot, demonstrating not only capture, but also storage.