The Oklahoma Department of Environmental Quality is out for comment until Feb. 9 on a draft approval for the Grand River Dam Authority (GRDA) to add waste from a powdered activated carbon injection system to be buried in a landfill at its coal-fired plant that is now only approved to take in fly and bottom ash, which are byproducts of coal combustion.
The powdered activated carbon (PAC) system is to be used to reduce mercury emissions from the flue gas at Unit 2 of the Grand River Energy Center in Mayes County, Okla., said a Nov. 2, 2014, letter from GRDA to the state agency. The PAC system is needed to meet federal Mercury and Air Toxics Standards (MATS) requirements. The waste from the PAC system will be mixed with the fly ash for landfill disposal. The letter said the PAC waste disposal would begin in January of this year.
The estimated amount of mercury that would be contained in the PAC waste is based on the mercury content of the plant’s largely Powder River Basin coal supply.
GRDA plans at this site to construct a natural gas-fired combined cycle combustion turbine (CCCT) called Unit 3. Unit 1 may be converted from coal-fired to natural gas-fired operation. Notable is that the plant underwent a name change, from the GRDA Coal Fired Complex to the Grand River Energy Center.
The plant currently consists of two coal-fired, Foster Wheeler opposed-wall boilers, designated as Units 1 and 2.
- Unit 1, which has a rated capacity of 490 MW, was built in 1978 and is designed to burn sub-bituminous (Wyoming) coal. Current air quality control equipment on Unit 1 consists of an electrostatic precipitator (ESP).
- Unit 2, which has a rated capacity of 520 MW, was built in 1982 and is designed to burn sub-bituminous (Wyoming) coal, or a blend of Wyoming and Oklahoma bituminous coal. Existing flue gas desulfurization (FGD) air quality control equipment on Unit 2 consists of a spray dryer absorber (SDA) followed by an electrostatic precipitator (ESP).