The Illinois Environmental Protection Agency on Oct. 16 issued a final air construction permit covering the plan by NRG Energy to convert the three coal-fired units (Units 6-8) at the Joliet power plant to burn natural gas.
The five affected boilers are served by three stacks, with two pairs of boilers having common stacks. When this conversion is completed for a boiler with installation of new natural gas burners, certain emission standards that are applicable to fuel combustion emission units that fire coal will no longer be applicable for the boiler, the agency noted.
In addition, certain existing emission control equipment and systems that were used when burning coal — the electrostatic precipitators for particulate, the selective non-catalytic reduction systems for NOx and the sorbent injection system for mercury — will no longer be needed.
As part of this project, a new natural gas-fired auxiliary boiler and new natural gas-fired fuel heaters would be constructed to support the operation of the existing boilers (the main boilers) on natural gas. This project will greatly reduce the emissions of most pollutants from the station. NRG is looking to comply with the U.S. EPA's Mercury and Air Toxics Standards with this project.
Bill Naglosky, Station Director at Joliet, told the crowd at a Sept. 24 public hearing on this permitting: "Joliet Generating Station can produce 1,468 MW of electricity, enough to power more than 1.6 million homes. Our stated practice and goal is to operate our units in full compliance with all environmental laws and regulations, to ensure that we consistently and constantly monitor our operations for compliance and to look for opportunities to improve our environmental performance. We are proud of the opportunity that the proposed gas conversion provides. We will keep jobs in the area for both our direct station employees and for hundreds and hundreds of contractors and laborers that we use throughout the year."
Notable is that Units 7 and 8 are part of what is often called Joliet 29, which is just across the Des Plaines River from Joliet 9, which consists of Unit 6. U.S. Energy Information Administration data shows that the plant's coal supplier earlier this year was Peabody Energy's North Antelope Rochelle mine in the Powder River Basin of Wyoming.