Citizens Thermal nears permit for coal-to-gas switch at Perry K

Citizens Thermal, which in recent months sought an Indiana Utility Regulatory Commission approval for a coal-to-gas switch at its Perry K steam plant, is also nearing a needed air permit change from the Indiana Department of Environmental Management (IDEM).

IDEM is taking public comment until Nov. 29 on the draft change. Citizens Thermal requested a change in the primary fuel used in boiler Units 12, 15, 16, 17 and 18. Boiler Units 12, 15 and 16 will no longer burn coal and will be converted to natural gas. Boiler Units 17 and 18 will change their primary fuel from fuel oil to natural gas, but will maintain the ability to burn fuel oil as a backup fuel.

This plant consists of the following emission units and pollution control devices:

  • One natural gas-fired Foster Wheeler boiler, identified as Emission Unit ID 11, with a nominal heat input capacity of 368 mmBtu/hr when firing natural gas, installed in 1938, with the primary fuel changed in 1998, and with a continuous emissions monitoring system for NOx and CO.
  • One Foster Wheeler boiler, identified as Emission Unit ID 12, which is dry bottom and wall fired, with a nominal heat input capacity of 352 mmBtu/hr, with natural gas fired during boiler startup and for flame stabilization, with emissions directed to two cold side electrostatic precipitators, installed in 1938, with a continuous opacity monitor, and with a continuous emissions monitoring system for NOx and SO2. After the fuel change from coal to gas, Emission Unit ID 12 would have a maximum heat input capacity of 439 mmBtu/hr.
  • One natural gas-fired Babcock & Wilcox boiler, identified as Emission Unit ID 13, with a nominal heat input capacity of 403 mmBtu/hr when firing natural gas, installed in 1946, with the primary fuel changed in 1998, and with a continuous emissions monitoring system for NOx and CO.
  • One natural gas-fired Babcock & Wilcox boiler, identified as Emission Unit ID 14, with a nominal heat input capacity of 403 mmBtu/hr when firing natural gas, installed in 1946, the primary fuel was changed in 1998, and with a continuous emissions monitoring system for NOx and CO.
  • One Babcock & Wilcox coal fired spreader stoker boiler, identified as Emission Unit ID 15, with a nominal heat input capacity of 324 mmBtu/hr, with natural gas fired during boiler startup and for flame stabilization, with emissions directed to one cold side electrostatic precipitator, installed in 1953, with a continuous opacity monitor, and a continuous emissions monitoring system for SO2 and NOx. After the coal-to-gas change, Emission Unit ID 15 would have a maximum heat input of 340 mmBtu/hr.
  • One Babcock & Wilcox coal fired spreader stoker boiler, identified as Emission Unit ID 16, with a nominal heat input capacity of 324 mmBtu/hr, with natural gas fired on boiler startup and for flame stabilization, with emissions directed to one cold side electrostatic precipitator, installed in 1953, with a continuous opacity monitor, and with a continuous emissions monitoring system for SO2 and NOx. After the coal-to-gas change, Emission Unit ID 16 would have a maximum heat input capacity of 340 mmBtu/hr.
  • One Combustion Engineering boiler, identified as Emission Unit ID 17, firing distillate oil, with a nominal heat input capacity of 228 mmBtu/hr and installed in 1974. After the oil-to-gas fuel change, Emission Unit ID 17 would have a maximum heat input capacity of 242 mmBtu/hr.
  • One Combustion Engineering boiler, identified as Emission Unit ID 18, firing distillate oil, with the capability to fire natural gas on boiler startup, with a nominal heat input capacity of 228 mmBtu/hr and installed in 1972. After the oil-to-gas fuel change, Emission Unit ID 18 would have a maximum heat input capacity of 242 mmBtu/hr.

Decommissioning of the truck loadout for waste coal ash will begin after boiler Units 12, 15 and 16 are fully converted from coal to natural gas. The same thing for one enclosed coal crusher with a throughput of 400 tons of coal per hour, constructed in 1945.

Citizens Thermal worked out conversion issues at IURC

Citizens Thermal official Korlon Kilpatrick II described a settlement on the issues related to the conversion in June 7 testimony filed at the Indiana URC. The settling parties agreed that Citizens Thermal’s plan to convert Boilers 12, 16, 17 and 18 is reasonable and in the public interest, based on Citizens Thermal’s evidence and its estimate that the total construction cost of implementing the Natural Gas Conversion Plan does not exceed $9m, exclusive of Allowance for Funds Used During Construction (AFUDC). The conversion is being done in place of more expensive emissions controls that would be needed to meet new U.S. Environmental Protection Agency rules.

The Natural Gas Conversion Plan does not contemplate immediate conversion of Boiler 15, which is a coal boiler, Kilpatrick said. Consequently, if Citizens Thermal completely eliminates the use of coal at the Perry K plant upon completion of the Natural Gas Conversion Plan, it will cease utilizing Boiler 15 until such time as that boiler is converted to burn natural gas or another fuel.

After the conversion of the Perry K boilers, the plant’s annual natural gas requirements will increase from about 1.0 BCF to 4.0 BCF. Coal for the Perry K plant is contracted at a level of 175,000 tons per year, said Robert Purdue, Director of Thermal Operations for Citizens Energy Group. Aug. 15 testimony from Purdue was filed at the Indiana URC in a fuel rate case. The Perry K steam plant is owned and operated by the Board of Directors for Utilities of the Department of Public Utilities of the city of Indianapolis, as successor trustee of a public charitable trust, d/b/a Citizens Thermal.

Citizens has contracted with an unnamed producer to provide coal over a three-year term, which ends on Dec. 31, 2013, Purdue noted. Citizens currently purchases about 175,000 tons of coal per year, which has decreased the past couple of years from 230,000 tons per year.

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.