The Wisconsin Department of Natural Resources is taking public comment until June 10, with a June 5 hearing planned, for air permitting on the ReACT multi-pollutant control system that Wisconsin Public Service wants to install on the coal-fired Weston Unit 3.
The DNR has made a preliminary determination that the application meets state and federal air pollution control requirements and that the permit should be approved. The June 5 hearing is to be held in Wausau, Wisc.
“Wisconsin Public Service Corporation (WPSC) is proposing to install a ReAct (Regenerative Activated Carbon) emissions control system on the Weston #3 power boiler,” said a DNR permit document. “The ReAct control system is a slowly moving bed of activated carbon which will be used to control missions for SO2, NOx and mercury. The activated carbon is not injected into the air stream, but held in the moving bed. There the ReAct system will also have a material recovery process which will produce commercial grade sulfuric acid for sale to off-site customers (the sulfuric acid is not being produced to be used onsite or by WPSC). In addition, a baghouse emissions control system will be installed after the ReAct system to ensure that particulate matter emission do not increase as a result of the installation of the ReAct system.”
The captured sulfur will be reclaimed from the spent activated carbon and processed into industrial grade sulfuric acid for resale, the DNR noted.
Over the objections of some parties, the Public Service Commission of Wisconsin on April 12 approved an application by Wisconsin Public Service to install the ReACT system on Weston Unit 3. The utility proposed to construct the facilities to meet the requirements of a Consent Decree agreed to between it and the U.S. Environmental Protection Agency that resulted from allegations by EPA of Clean Air Act violations at WPSC’s Weston and Pulliam coal plants. WPSC also proposed to use the new facilities to comply with future air pollution regulations and help maintain a balanced generation portfolio.
WPSC estimates that the cost of ReACT project construction is $275m, excluding allowance for funds used during construction (AFUDC). The AFUDC associated with the project would be $41m.
The Weston plant is located along the Wisconsin River, about seven miles south of the city of Wausau in Marathon County. It includes four coal-fired units, two natural gas/oil-fired combustion turbine generators, and auxiliary systems. Weston 3 is the second largest coal-fired unit, with a capacity of 320 MW using primarily sub-bituminous Powder River Basin coal. It has been in service since 1981. Existing emissions control facilities include: fabric filters installed in 2000 for better particulate control, low NOx burners installed in 2009, and an activated carbon injection system installed in late 2009 for mercury emissions control.