General GRU Information
Learn how GRU maintains good air quality
Monitoring Air Emissions:
We monitor our emission through the use of sophisticated electronic analyzers called Continuous Emission Monitors (CEMS). These monitors provide us with the information necessary to assure that our emissions are at or below all state and federal air emissions limits. We currently use CEMS to monitor the following:
- Oxides of Nitrogen (NOx)
- Sulfur Dioxide (SO2)
- Carbon Dioxide (CO2)
- Opacity
Controlling Air Emissions:
We control our emissions of SO2 by purchasing fuels (coal, distillate and residual fuel oils, and natural gas) that contain low concentration of sulfur. These low concentrations of sulfur in the fuel result in reduced amounts of SO2 produced during the combustion process.
Particulate emissions from our oil and gas fired units are also controlled by the quality of fuel we burn. Natural gas and low-sulfur fuel oils inherently burn cleaner and produce less particulate matter. Unit #2 at the Deerhaven Generating Station, combusts coal but is equipped with an electrostatic precipitator which removes over 99% of the particulates produced during the combustion process.
The control of NOx emission is generally accomplished through the use of fuels that contain lower quantities of nitrogen and/or though combustion techniques which minimize the formation of NOx in the first place. The combustion turbine (DH CT3) at our Deerhaven Generating Station and the combined cycle unit (JRK CC1) at our J.R. Kelly Generating Station are both equipped with NOx control devices, which minimize the formation of NOx when firing natural gas and fuel oil.
Deerhaven 2 Retrofit:
The U.S. Environmental Protection Agency passed the Clean Air Interstate Rule (CAIR) and the Clean Air Mercury Rule (CAMR) in March 2005. These rules require levels of sulfur dioxide (SO2), nitrogen dioxide (NO2) and mercury emission to be reduced. We plan to achieve greater emission reductions than required under CAIR and CAMR by using methods including Dry Flue Gas Desulfurization (FGD) with Fabric Filter (FF) to reduce sulfur dioxide levels and Selective Catalytic Reduction (SCR) to reduce nitrogen oxide levels. All of these methods will also reduce mercury emissions.
