NIPSCO nears permit for dry sorbent injection at Schahfer plant

The Indiana Department of Environmental Management (IDEM) on June 7 put out for 30 days of public comment a draft air permit change that would allow Northern Indiana Public Service to install additional emissions controls on two units of its coal-fired R.M. Schahfer power plant.

If approved by IDEM’s Office of Air Quality (OAQ), this proposed modification would allow NIPSCO-R.M. Schahfer Generating Station to add to the original project for construction of forced oxidation limestone flue gas desulfurization (FGD) systems on Units 14 and 15 to reduce SO2 emissions, and selective non-catalytic reduction (SNCR) technology on Unit 15 in order to reduce NOx. NIPSCO is adding an alkali reagent injection system that will be installed to control sulfuric acid mist emissions from Unit 14 and Unit 15.

The permit for the FGD and SNCR construction was issued in April 2011. As the project progressed the utility identified additional equipment that needed to be installed as part of the FGD project. In the original permit application NIPSCO noted that alkali reagent injection systems will also be installed to control sulfuric acid mist emissions from Unit 14 and Unit 15.

At the time of original permitting for the FGDs, limited information was available regarding the control system. However, as detailed design work progressed, NIPSCO selected a dry sorbent injection (DSI) system that will use Trona reagent to control sulfuric acid mist emissions.

The units at the R.M. Schahfer plant are:

  • One cyclone coal-fired boiler (Unit 14), which went into commercial operation in 1976, with a design heat input capacity of 4,650 million Btu per hour (MMBtu/hr), combusting No. 2 fuel oil and/or natural gas for ignition and as supplemental fuels, using an electrostatic precipitator (ESP) for control of particulate matter and exhausting to stack 14. Unit 14 has a selective catalytic reduction (SCR) system for NOx control. The company plans to install a Reagent Injection System on Unit 14 by 2014, and plans to install and operate the FGD system on Unit 14 by 2014.
  • One dry bottom pulverized coal-fired boiler identified as Unit 15, with commercial operation in 1979, and a design heat input capacity of 5,100 million Btu per hour (MMBtu/hr), with low NOX burners (replaced in 2008-2009), combusting No. 2 fuel oil and/or natural gas for ignition and as supplemental fuels, using an ESP with a flue gas conditioning (FGC) system for control of particulate matter, and exhausting to stack 15. The utility plans to install a Reagent Injection System on Unit 15 by 2016. It plans to install and operate SNCR on Unit 15 by 2013 and FGD by 2016.
  • One dry bottom pulverized coal-fired boiler (Unit 17), with commercial operation begun in 1983, with a design heat input capacity of 3,967 million Btu per hour (MMBtu/hr) based on 30-day averages from coal sampling. It has low NOX burners, combusts No. 2 fuel oil and/or natural gas for ignition and as supplemental fuels, uses an ESP for control of particulates, and exhausts through a limestone-based FGD system to stack 17. Unit 17 has been approved to fire blends of coal and petroleum coke.
  • One dry bottom pulverized coal-fired boiler identified as Unit 18, with commercial operation begun in 1986, with a design heat input capacity of 3,967 million Btu per hour (MMBtu/hr) based on 30-day averages from coal sampling, with low NOX burners, combusting No. 2 fuel oil and/or natural gas for ignition and as supplemental fuels, using an ESP for control of particulates, and exhausting through a limestone-based FGD to stack 18. Unit 18 has been approved to fire blends of coal and petroleum coke.
  • Two natural gas-fired combustion turbines, identified as 16A and 16B, constructed in 1979, each with a design heat input capacity of 1,450 million Btu per hour (MMBtu/hr), each using water injection as needed for NOX control, exhausting to stacks 16A and 16B, respectively.

NIPSCO parent NiSource (NYSE: NI) reported in its April 30 Form 10-Q report, which covered the first quarter of this year, on air compliance matters. “Initial preparation and construction of the approximately $250 million FGD project began at the Michigan City generating station,” the company said about another of its coal plants. “The more than $500 million FGD project at Northern Indiana’s Schahfer generating station remains on track, with units to be placed into service in the fourth quarter of 2013 and in 2014.”

About Barry Cassell 20414 Articles
Barry Cassell is Chief Analyst for GenerationHub covering coal and emission controls issues, projects and policy. He has covered the coal and power generation industry for more than 24 years, beginning in November 2011 at GenerationHub and prior to that as editor of SNL Energy’s Coal Report. He was formerly with Coal Outlook for 15 years as the publication’s editor and contributing writer, and prior to that he was editor of Coal & Synfuels Technology and associate editor of The Energy Report. He has a bachelor’s degree from Central Michigan University.