Scrubbers, technically referred to as flue gas desulfurization (FGD) units, remove almost all sulfur dioxide from power plant emissions. In addition, the FGD units, in conjunction with existing environmental controls, capture significant mercury and fine particulate emissions.
DP&L was the first utility in the United States to use the FGD technology commercially, which was developed by the Chiyoda Corporation. The system pumps flue gas through a limestone and water bath as opposed to the traditional method of spraying gases with a limestone mist. DP&LÂ’s early adoption of this type of system resulted in capital costs well below industry averages. In addition, the simple design will have lower operating and maintenance expense compared to traditional scrubber designs.
“The scrubbed unit at Killen has been operating for about a year now, and we are very pleased with its performance and reliability,” said Mr. Barbas. “It is removing more than 95% of the sulfur dioxide and having positive impacts on particulate reduction.”
DP&LÂ’s investment in the FGD units is approximately $600 million. On a DP&L system-wide basis, the scrubber at the Conesville generating plant is expected to be on line next spring as planned. Conesville is jointly owned with and operated by American Electric Power (AEP). By mid-2009, almost 90% of DP&LÂ’s generation output will be produced by units with environmentally friendly scrubbers.