Michigan agency takes comment on Presque Isle coal retrofits

The Michigan Department of Environmental Quality’s Air Quality Division (AQD) on Sept. 24 issued a draft air permit-to-install for new air emissions controls for the coal-fired Presque Isle power plant in the state’s Upper Peninsula.

The plant is operated by Wisconsin Electric Power d/b/a We Energies. These emissions projects are to be paid for by Michigan-based Wolverine Power Supply Cooperative in exchange for a one-third ownership stake in the plant.

The permit application is for a proposed modification to and operation of five existing coal-fired  units. The utility proposes to add air pollution control systems to each of the existing units (identified as EUBOILER5, EUBOILER6, EUBOILER7, EUBOILER8 and EUBOILER9).

The additional air pollution control systems will reduce NOx, acid gases (including SO2), and mercury emissions. Prior to acting on this application, the AQD is holding a public comment period (that runs to Oct. 24) and a public hearing, if requested in writing, to allow all interested parties the opportunity to comment on the proposed PTI.

Presque Isle is an existing generating facility located in Marquette, Mich. The proposed project will consist of adding: new low-NOx burners to EUBOILER5 and EUBOILER6; overfire air systems for all five boilers to further control NOx; spray dryer absorbers (SDA) to EUBOILER5, EUBOILER6 and EUBOILER7 for acid gas control; dry sorbent injection (DSI) to EUBOILER8 and EUBOILER9 for acid gas control; and powdered activated carbon (PAC) injection to EUBOILER5, EUBOILER6 and EUBOILER7 for mercury (Hg) control.

A new silo will be installed to store reagent for the SDA control systems and one new silo will be installed for PAC storage. A new sorbent milling system will also be installed for grinding reagent used for the DSI along with an associated DSI silo.

There will be no capacity increase or life extension work performed for these five units as part of this project, the agency noted.

The units are:

  • EUBOILER5 – Boiler #5 is a Riley pulverized coal wall fired dry bottom utility boiler. Nameplate steam capacity rating is 615,000 lb/hr. The heat input capacity is about 995 MMBTU/hr. The boiler serves a GE steam turbine/ generator set rated at 78,973 KW. Combustion equipment includes individual over fire air systems and new low NOX burners. Emission controls are an electrostatic precipitator (ESP) and fabric filter baghouse installed in series, SDA prior to the fabric filter for SO2 and HAP acid gas control, and PAC injection for mercury control.
  • EUBOILER6 – Boiler #6 is a Riley pulverized coal wall fired dry bottom utility boiler. Nameplate steam capacity rating is 615,000 lb/hr. The heat input capacity is approximately 995 MMBTU/hr. The boiler serves a GE steam turbine/generator set rated at 78,973 KW. Combustion equipment includes individual overfire air systems and new low-NOX burners. Emission controls are an ESP and fabric filter baghouse installed in series, SDA prior to the fabric filter for SO2 and HAP acid gas control, and PAC injection for mercury control.
  • EUBOILER7 – Boiler #7 is a Riley pulverized coal wall fired dry bottom utility. Nameplate steam capacity is 615,000 lb/hr. The heat input capacity is about 1010 MMBTU/hr. The boiler serves a GE steam turbine/generator set rated at 78,982 KW. Combustion equipment includes individual overfire air systems. Emission controls are an ESP and fabric filter baghouse installed in series, SDA prior to the fabric filter for SO2 and HAP acid gas control, and PAC injection for mercury.
  • EUBOILER8 – Boiler #8 is a Riley pulverized coal wall fired dry bottom utility boiler. Nameplate steam capacity rating is 615,000 lb/hr. The heat input capacity is about 1010 MMBTU/hr. The boiler serves a GE steam turbine/generator set rated at 78,982 KW. Bottom ash from Boilers #5 and #6 is reburned in this boiler. Combustion equipment includes individual overfire air systems. Emission controls are an ESP and fabric filter baghouse (shared with Boiler #9) installed in series, DSI prior to the fabric filter for SO2 and HAP acid gas control, and PAC injection for mercury control.
  • EUBOILER9 – Boiler #9 is a Riley pulverized coal wall fired dry bottom utility boiler. Nameplate steam capacity is 615,000 lb/hr. The heat input capacity is around 1010 MMBTU/hr. The boiler serves a GE steam turbine/generator set rated at 78,982 KW. Bottom ash from Boilers #5 and #6 is reburned in this boiler. Combustion equipment includes individual overfire air systems. Emission controls are an ESP and fabric filter baghouse (shared with Boiler #8) installed in series, DSI prior to the fabric filter for SO2 and HAP acid gas control, and PAC injection for mercury control.

Wolverine’s buy of a third of the plant has gotten various approvals

The Public Service Commission of Wisconsin (PSCW) on June 21 issued a final decision approving the sale by Wisconsin Electric Power (WEPCO) of the one-third stake in Presque Isle to Wolverine. This deal has also gotten approvals from the Michigan Public Service Commission and the Federal Energy Regulatory Commission.

WEPCO and Wolverine have entered into an Ownership Exchange and Participation Agreement under which Wolverine will provide all of the capital to undertake an air quality control system (AQCS) project at the plant, estimated to cost $130m-$140m, in exchange for receiving about a one-third undivided ownership interest in the plant. WEPCO would retain two-thirds of the plant.

WEPCO and Wolverine have also entered into an Operating and Maintenance Agreement under which WEPCO will act as agent for itself and for Wolverine as co-owners of Presque Isle, in connection with the management, control, operation, and maintenance of Presque Isle, and for the planning, design, engineering, procurement, licensing, permitting, construction, completion, startup, and testing of capital projects, other than the AQCS project.

WEPCO stated that the plant is needed to serve customers power supply needs in the greater Marquette, Mich., area. It has discussed the possibility of plant retirement with the Midcontinent Independent System Operator (MISO), and American Transmission Co. LLC. WEPCO filed an application with MISO in October 2011, to have MISO study the possibility of retiring PIPP. In January 2012, MISO replied that “retirement of the units prior to installation of transmission upgrades to the greater Marquette, MI area would result in violation of applicable reliability standards, creating unacceptable reliability issues.”

Presque Isle Units 5 and 6 are capable of firing both bituminous and sub-bituminous coal, while Units 7-9 are capable of firing sub-bituminous coal, and the application for the PTI authorization said those fuel options will remain unchanged after the emissions projects are completed.

U.S. Energy Information Administration data shows deliveries to the plant earlier this year from the Spring Creek mine in the Montana Powder River Basin of Cloud Peak Energy (NYSE: CLD), and the North Antelope Rochelle mine of Peabody Energy (NYSE: BTU) and the Black Thunder mine of Arch Coal (NYSE: ACI) in the Wyoming end of the PRB.

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.