Duke Energy Indiana okayed for new air controls at Cayuga coal plant

The Indiana Department of Environmental Management on Nov. 29 issued a final air permit approval to Duke Energy Indiana for the addition of new emissions controls, including dry sorbent injection, on the two coal-fired units at the Cayuga power plant.

The plant would get two dry sorbent injection (DSI) systems for SO3 control, one for each unit, to be installed by 2015. The plant would also get two activated carbon injection (ACI) systems for mercury control, one for each unit, scheduled to be installed by 2015. Also added under the permit approval will be two dry ash handling systems, one for each unit, to be installed by 2015. These systems had been previously approved, but the utility had to permit certain design changes that came about during detailed planning for the new controls.

The units getting these new controls are:

  • One dry bottom, pulverized coal-fired boiler (Boiler No. 1), installed in 1967, with a nominal heat input capacity of 4,802 million Btu per hour (MMBtu/hr), with an electrostatic precipitator (ESP) for control of particulate matter and flue gas desulfurization (FGD) for control of SO2, exhausting to stack 1. Stack 1 has continuous emissions monitors (CEMs) for NOX and SO2 and a continuous opacity monitor (COM). Boiler No. 1 was configured with a low NOX burner in 1993. Selective catalytic reduction (SCR) to control NOx, DSI to control SO3, and ACI to assist in control of Hg emissions are scheduled to be installed by 2015.
  • One dry bottom, pulverized coal-fired boiler (Boiler No. 2), installed in 1968, with a nominal heat input capacity of 4,802 million Btu per hour (MMBtu/hr), with an ESP for control of particulate matter and an FGD system for control of SO2, exhausting to stack 2. Stack 2 has CEMs for NOX and SO2 and a COM. Boiler No. 2 was configured with a low NOX burner in 1993. SCR to control NOx, DSI to control SO3, ACI to help control Hg emissions scheduled to be installed by 2015.

The Duke Energy Indiana website noted that the utility is currently is investing $400M at 1,104-MW Cayuga plant to install SCR units that effectively reduce nitrogen oxides, as well as other equipment to enhance mercury removal. The Indiana agency approved the SCR air permit in September 2012. In 2008, the company invested approximately $500m for the two FGDs to control SO2 emissions at Cayuga.

On April 3, the Indiana Utility Regulatory Commission approved a series of air emissions projects under the utility’s Phase 2 plan, which included: 

  • Cayuga Unit 1 – SCR, DSI, ACI, arsenic mitigation system, mercury re-emission chemical injection system, in-service by December 2014; and
  • Cayuga Unit 2 – SCR, DSI, ACI, arsenic mitigation system, mercury re-emission chemical injection system, in-service by June 2015.
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.