Wisconsin Public Service permits new Pulliam coal plant air controls

The Wisconsin Department of Natural Resources is out for public comment until April 9 on a draft air permit to allow Wisconsin Public Service Corp. to install new air controls at the coal-fired Pulliam power plant.

The utility is proposing to install dry sorbent injection (DSI) and calcium bromide injection systems on Pulliam Units 7 and 8 (boilers B26 and B27) and expand the existing powdered activated carbon (PAC) injection system currently installed on boiler B27 to include boiler B26.

These pollution controls are being installed to comply with the federal Mercury and Air Toxics Standards (MATS) rule, which has a compliance date of April 16, 2015. WPS has also requested that the conditions of an air consent decree it worked out with the federal government be incorporated into the construction permit.

The DSI system will consist of a storage silo, two mills, systems to inject the DSI into the boiler flue gas stream and associated piping. DSI will be delivered by truck to a new DSI silo where emissions from loading and unloading will be controlled by a bin vent filter. The DSI material will be either trona or sodium bicarbonate. Only one of these sorbents can be injected at a time.

From the silo, the DSI will be pneumatically conveyed through fully enclosed piping to the new Pulliam Unit 7 mill or Pulliam Unit 8 mill. The piping and mills are totally enclosed processes and the mills will be contained within enclosed semi-trailers. The milled dry material is then pneumatically conveyed through enclosed piping and injected into the boiler flue gas path between the air heaters and the electrostatic precipitator (ESP). Alternatively, DSI material can bypass the mills and be conveyed through enclosed piping and directly injected into the boiler flue gas path between the air heaters and the electrostatic precipitator.

The expansion of the PAC injection system includes the addition of an injection system for boiler B26 and associated piping. PAC will be delivered by truck to an existing PAC storage silo where emissions from loading and unloading will be controlled by a bin vent. From the silo, the PAC will be pneumatically conveyed through fully enclosed piping and injected into the boiler flue gas path between the economizer and the air heaters.

The new calcium bromide injection system will consist of a storage tank for the liquid CaBr2 solution and piping to deliver the solution to the boiler B26 and B27 coal feeders. Addition of CaBr2 to the coal being fed to the boilers will enhance the collection of mercury, as demonstrated during a research and testing project authorized under a prior DNR approval.

J.P. Pulliam is located near the mouth of the Fox River in Green Bay, Wisc. The primary emission sources at this location are four coal-fired boilers, rated between 693 and 1510 mmBtu per hour. These boilers were built between 1949 and 1964. Natural gas is burned in a series of burners located on each boiler as a startup and supplemental fuel. Electrostatic precipitators are used to control particulate matter emissions from the boiler exhaust gases. Other significant emission sources at the plant include a combustion turbine, natural gas heaters used to thaw frozen coal contained in rail cars, two natural gas pipeline station heaters rated at 4.0 million Btu/hr each, and particulate matter emissions associated with coal and ash handling at the site.

Utility parent Integrys Energy Group (NYSE: TEG) noted in its Feb. 27 annual Form 10-K report that in connection with the WPS consent decree with EPA, early retirement of the Weston Unit 1, Pulliam Unit 5, and Pulliam Unit 6 is probable. These units have an aggregate generating capacity of 166.9 MW (based on summer 2014 capacity ratings). This consent decree was approved by a U.S. District Court in March 2013.

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.