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Clean Air Project

Using wet flue gas desulfurization technology - a “scrubber” system - the Clean Air Project captures at least 80 percent of the mercury in the coal and reduces sulfur dioxide emissions by more than 90 percent at Merrimack Station in Bow, New Hampshire.

Emissions Control Technology at Merrimack Station

Key Benefits:

  • Drastic reduction in mercury and sulfur emissions, Merrimack is one of the cleanest coal plants in the nation.
  • Continues to support New England’s fuel diversity, enhancing the stability of the power supply in the region.
  • Coal generation powers 45 percent of the nation and 6 percent of New England.
  • Will serve as a “bridge” over the next 10 to 20 years as we develop and build alternative energy sources on a much larger scale.

What is “scrubber technology?”

During a wet scrubber process, limestone is mixed with water to create a slurry, which is “rained down” on the flue gas before it enters the stack. The wet slurry absorbs the SO2 and reacts to form gypsum. After a dewatering process, the solid gypsum is sold to wallboard manufacturers. The mercury is removed in a new state-of-the-art waste water treatment facility.

Please click here for a larger version of the diagram.

Clean Air Project Awards:

  • 2013 – Environmental Business Council’s New England Outstanding Environmental-Energy Technology Application Achievement Award
  • 2013 – International Green Apple Awards for Environmental Best Practice 2013
  • 2012 – Power Magazine Top Plants: Six Innovative Coal-Fired Plants