Hot Topic Hour, January 19, “Making Coal Plants Green”

On January 19, Bob McIlvaine discussed novel ways to make coal-fired power plants green by taking advantage of various synergies within a plant, as well as synergies with other types of facilities. For example:

• Produce a saleable hydrochloric acid by prescrubbing the flue gas prior to the SO₂ scrubber. This eliminates the chloride problem in gypsum from the FGD and creates a saleable chemical product.
   
• Capture CO₂ and sell the gas for enhanced oil or gas production, as Saskpower is doing at its Boundary Dam Power Station in Saskatchewan.
   
• Take advantage of efficiency improvements through optimization and neural network technologies.

Bob also discussed the concept of co-locating a municipal wastewater treatment plant and a power plant. Power plants require large quantities of water, particularly for cooling. Treated municipal wastewater could be recycled as cooling water. In addition, municipal sludge could be burned for energy at the power plant and waste steam from the power plant can be used to improve sewage treatment operations. Integrating power and wastewater plants is particularly appealing given that 81 percent of planned power plants in the U.S. are within ten miles of a municipal treatment plant. 

A prime example of a “green” power plant is Dong Energy’s Asnaes Power Station in Denmark which is integrated with the adjacent Inbicon Biomass Refinery.  Energy and byproducts are exchanged between the two facilities in over 20 mutually beneficial ways.