The Florida Department of Environmental Protection on Feb. 11 issued a final air construction permit that authorizes the installation and operation of several pollutant reduction systems at the Orlando Utilities Commission‘s (OUC) Stanton power plant.
Stanton Energy Center is a nominal 1,876-MW facility. This facility consists of: two fossil fuel-fired steam units (Units 1 and 2); and two combined cycle combustion turbine generators (Units A and B).
Units 1 and 2 fire coal and No. 6 fuel oil, and have a combined output of 936 MW. Unit 1 began operation in 1987 and Unit 2 began operation in 1996. Units 1 and 2 have the following pollution control equipment: NOX is controlled by low NOX burners (LNB), over fire air (OFA) systems and selective catalytic reduction (SCR) systems; PM emissions are controlled by dry electrostatic precipitators (ESP); and SO2 emissions are controlled by FGD scrubbers.
OUC was approved on Feb. 11 to install and operate several other air systems, including: Fuel Lean Gas Reburn (FLGR) on Units 1 and 2 to reduce NOx emissions; upgrades to the wet FGD scrubber system on Unit 2 to reduce SO2; chemical spray technology based on spray application of halogen-based additives such as calcium bromide (CaBr2) into the coal feeder and sodium hydrosulfide (NaHS) into the wet FGD system; and a portable ACI system. The portable ACI system will be used in combination with chemical spray technology to mitigate mercury emissions. The proposed portable ACI system may be used on either Unit 1 or Unit 2, as needed.
More details of these new systems are:
- The FLGR will use natural gas-firing above the OFA zone in each unit of up to 10% of the permitted heat input rate (i.e., nominal 480 million British thermal units per hour on a 4-hour block average). Natural gas will displace coal or other authorized fuels. The heat input rate from the FLGR systems do not increase the maximum heat input rate for either unit.
- Orlando is authorized to install some or all of this equipment for the FGD system on Unit 2: a new distribution tray or an additional spray level with increased recycle pump capacity; wall rings to direct both flue gas and slurry; and modifications to the spray nozzles, nozzle arrangement and piping. These upgrades to the wet FGD system on Unit 2 are similar to the upgrades already completed on Unit 1.
- The permittee is authorized to modify the induced draft fan on Unit 2 to increase the fan speed to account for the additional pressure drop caused by the scrubber upgrades.
- Orlando is authorized to install a portable ACI system for use on either Units 1 or 2. The permittee is authorized to use a chemical spray technology consisting of halogen-based additives such as calcium bromide (CaBr2) into the coal feeder and sodium hydrosulfide (NaHS) or an equivalent sulfide-donating liquid agent, into the recirculating pumps of the wet FGD system for Units 1 and 2. The portable ACI system will be used in combination with chemical spray technology to mitigate mercury emissions. The portable ACI system may be used on either Unit 1 or Unit 2.