The Wisconsin Department of Natural Resources is taking comment until June 24 on a draft air permit approval that would allow Wisconsin Power & Light (WPL) to use coal additives to help reduce air emissions at the 1,054-MW Columbia Energy Center (CEC) in Pardeeville, Wisconsin.
“WPL is proposing to partner with Clean Coal Solutions, LLC (CCS) to construct and operate a Fuel Additive Process that will provide refined coal for combustion in CEC’s generating units 1 and 2,” said a DNR permit document. “The CCS refined coal involves adding multiple additives (A1, A2, B) to the coal supply prior to combustion. The additives will aid in the removal of mercury (Hg) and reduce nitrogen oxides by adding proprietary reagents to the coal. The trade marked M45-PC additive technology systems will be used in the boilers.
“In addition to minor changes at the coal fired boilers, the project will result in additional fugitive emissions from transporting the additive ingredients into the plant (to the silos) and a liquid additive, emissions from the silos (mainly when receiving product), and indoor fugitive emissions from dry ingredient bending (within a structure). The facility noted subsequently that they won’t have a ribbon blender and don’t anticipate emissions from the indoor operations.”
A construction permit for this plant was issued in November 2011 authorizing the construction of a spray dryer to control acid gases and a baghouse to control particulate matter for each boiler B21 and B22, with supporting lime silos and powered activated carbon (PAC) systems. This was referred to as the Air Quality Control Systems (AQCS) project.
More recently, on Jan. 7, a construction permit was issued for a project to increase efficiency and recover lost capacity which was reviewed under PSD and established PSD BACT for carbon monoxide emissions and greenhouse gas emissions. These efficiency projects are part of the CEC Comprehensive Asset Management Plan (CAMP) Program. The CAMP projects include the following equipment/activities:
- steam turbine upgrade, and
- replacement of pulverizers.
The upgrades to the steam turbine and replacement of the pulverizers are expected to allow WPL to improve the heat rate of both Units 1 and 2 as well as expand the periods in time between routine planned maintenance outages.
WPL initially requested that this new coal additive project to use a “refined” coal be considered an exempt (from permitting) change. However, in light of the above projects, and the need to make changes to the boiler fuel (authorizing use of ‘refined’ coal); this new project is being evaluated through a construction permit. The only new emission sources are particulate matter from two dry material silos and fugitive truck traffic emissions from bringing the coal additives into the plant site.
The applied materials are Brucite (a mineral, mainly magnesium hydroxide), urea, and a proprietary halide material to reduce the emissions of mercury. Due to the use of the additives to make a ‘refined’ coal, there may be some reductions in emissions of mercury and NOx.