The Indiana Department of Environmental Management (IDEM) is taking public comment until Jan. 30 on a draft air permit change that would allow Northern Indiana Public Service Co. (NIPSCO) to build new SO2 scrubbers on two units at its coal-fired R.M. Schahfer plant in Wheatfield, Ind.
The company applied to operate a forced oxidation limestone flue gas desulfurization (FGD) system on Units 14 and 15 to reduce SO2 emissions, and also to install selective non-catalytic reduction (SNCR) technology on Unit 15 in order to reduce NOx emissions. The permit for this construction was issued in April 2011. As the project progressed the company identified additional equipment that needed to be installed as part of the FGD project, with that equipment covered by this air permit change.
Unit 14 consists of one cyclone coal-fired boiler, which began commercial operation in 1976. It already has an electrostatic precipitator (ESP) for control of particulate matter and a selective catalytic reduction (SCR) system for NOx. Under a January 2011 clean-air consent decree worked out with the U.S. Environmental Protection Agency, NIPSCO plans to install and operate an FGD system on Unit 14 by 2014, IDEM noted.
Unit 15 consists of one dry bottom pulverized coal-fired boiler, which began commercial operation in 1979. It has low-NOx burners (replaced in 2008-2009), and an ESP with a flue gas conditioning system for control of particulate matter. NIPSCO plans to install and operate the SNCR system on Unit 15 by 2013 and the FGD system by 2016.
Also at the same plant is Unit 17, which consists of a dry bottom pulverized coal-fired boiler, which already has low-NOX burners, an ESP and a limestone-based FGD system. Unit 17 has been approved to fire blends of coal and petroleum coke, IDEM noted.
There is also Unit 18, which is a dry bottom pulverized coal-fired boiler that has low-NOx burners, an ESP and a limestone-based FGD system. Unit 18 has also been approved to fire blends of coal and petroleum coke.
Indiana commission approves scrubber projects
NIPSCO has also been seeking approval from the Indiana Utility Regulatory Commission for a number of clean-air projects needed to comply with the consent decree. In mid 2011, to better address certain issues raised by intervenors in the case, NIPSCO had the case split into two, called Phase I and Phase II.
Phase I addresses the following three projects; the Schahfer Unit 14 FGD; facilities common to the Schahfer Unit 14 and 15 FGDs; and the Schahfer Unit 15 FGD. Phase II includes the following projects: Michigan City Unit 12 FGD; Bailly Unit 7 SCR Duct Burners; Bailly Unit 8 SCR Duct Burners; Michigan City Unit 12 SCR Duct Burners; Schahfer Unit 14 SCR Duct Burners; Schahfer Unit 15 SNCR; and continuous particulate monitors for Units 7, 8, 12, 14, 15, and Schahfer Units 17 and 18.
On Dec. 28, the commission approved the Phase I projects, with the Phase II projects still under review. The latest cost estimates provided by NIPSCO for the Phase I projects were: $203m for the Unit 14 FGD, $104m for Unit 14 and 15 common facilities, and $193m for the Unit 15 FGD.
The commission noted that besides the consent decree, NIPSCO will also need to comply with new federal and state environmental regulations, including EPA's final Cross-State Air Pollution Rule and EPA’s proposed Utility Maximum Achievable Control Technology rule for air toxics.
NIPSCO’s Multi-Pollutant Compliance Plan calls for the installation of FGD systems on Schahfer Units 14 and 15 and Michigan City Unit 12. To control NOx, the plan includes the installation of SNCR on Schahfer Unit 15 and Duct Burners on Bailly Unit 7, Bailly Unit 8, Michigan City Unit 12 and Schahfer Unit 14.
In a December 2010 order, the commission approved NIPSCO's request for the Schahfer Unit 14 wet FGD and certain common facilities to be shared with an FGD to be installed on Schahfer Unit 15. In the Phase I case approved Dec. 28, NIPSCO requested approval of its updated cost estimates for the Schahfer Unit 14 wet FGD and common facilities to be shared with the Schahfer Unit 15 FGD.
The NIPSCO generating facilities have a total capacity of 3,322 MW and consist of numerous separate generation sites, including R.M. Schahfer, Michigan City, Bailly, the gas-fired Sugar Creek plant and two hydroelectric generating sites near Monticello, Ind. Of the total capacity, 77.5% is from coal-fired units, 22.2% is from natural gas-fired units and 0.3% is from hydroelectric units.
Schahfer is located two miles south of the Kankakee River in Jasper County, has four coal-fired units (Units 14, 15, 17 and 18) and is the largest of NIPSCO's generating stations, providing over 50% of its generation capacity.
Michigan City is on the shore of Lake Michigan in Michigan City, Ind. Michigan City formerly had the two oldest generating units on NIPSCO's system, Units 2 and 3, which have been removed from service. Michigan City's newer Unit 12 remains in service and burns low-sulfur coal.
Bailly is located on a 100-acre site on the shore of Lake Michigan in Porter County, Ind. Bailly has a Pure Air FGD facility to allow it to use Midwestern high-sulfur coal.