The FDS Project incorporates the principles of "Natural Capitalism" by using a world class integrated design and new innovative process technologies to minimize environmental impacts including air pollutant emissions. This approach leverages project business objectives to meet common goals of improving the environment.
The use of waste heat from the non-recovery coking process to generate electricity will also be done with no additional air pollutant emissions. FDS believes that the synergistic approach that combines industrial manufacturing with electrical generation is just the type of advanced energy project Ohio needs to serve as a model to retaining industrial manufacturing jobs into the future.
Air pollution controls for production operations at the FDS Coke Plant are state-of-the-art. These controls will meet and in many cases exceed existing environmental regulatory requirements such as Best Available Control technology (BACT). As a result, air pollution controls used at the FDS Coke Plant will set a new higher environmental standard for future coke plants.
When operational, the FDS Coke Plant will have the lowest overall emission rate of air pollutants per ton of coal charged of any non-recovery coking plant in the US. Based on 2006 USEPA data, the FDS Project will be producing coke and generating electricity on a per MegaWatt basis with approximately 40% of the SO2, 59% of the NOx, and 59% of the CO2 emissions that public utility coal-fired power plants in Northwest Ohio have to only generate electricity.
Ohio EPA-approved ambient air quality modeling demonstrates that FDS Coke Plant's air pollutant emissions do not adversely impact local ambient air quality. Modeled maximum air pollutant concentrations in the ambient are generally less than 50% of the allowable national ambient air quality standard (NAAQS).
The FDS Co-Generation Facility will annually generate approximately 1 million MegaWatt-Hours of electricity with no additional air pollutant emissions. This "zero emission" outcome results in the avoidance of 3,000 to 6,000 tons of sulfur dioxide (SO2), 2,000 to 3,000 tons of nitrogen oxides (NOx), and 50 to 100 pounds of mercury emissions if the electricity generated by the FDS Project is not produced by existing coal-fired utility plants.
Sulfur Dioxide - SO2
Sulfur dioxide (SO2 ) emissions from the FDS Coke Plant will be reduced approximately 92% through the combination of low sulfur coal and use of a flue gas desulfurization (FGD) system. Ohio EPA has determined that the FGD system meets BACT for SO2 . The system operates by injecting a slurry of calcium carbonate (a reagent) into the cold-end waste gas ducting to neutralize and absorb the SO2 .
The FGD system is comprised of two (2) Spray Dryer Absorber (SDA) vessels sized to treat 100% of the maximum design gas flow. One SDA vessel will be in operation, the second SDA will be a 100% standby. This and the use of other redundant systems will allow routine maintenance to be carried out on-line for the FGD system.
Upon entering the SDA, waste gas containing the combustion byproducts and particulate comes into intimate contact with finely atomized droplets of fresh lime reagent and water which absorb and neutralize the SO2 and other acid gases contained in the flue gas stream. The scrubbed waste gas and resulting particulate matter (fly ash, scrubber residual and spent AC) exits the SDA vessel through a single outlet duct that connects to the fabric filter (baghouse) inlet. The FGD baghouse controls these particulates before the exhaust gas exits the Main Stack.
Nitrogen Oxides - NOx
The FDS Coke Plant's non-recovery coke ovens operate under negative pressure with the hot waste gas exhausted to a common waste gas-collecting duct. Temperatures within common waste gas-collecting duct will reach up to 2,100° F. As a result, this collecting duct serves as an afterburner tunnel that has been approved by USEPA and Ohio EPA as BACT for reduction of nitrogen oxide (NOx ) emissions from non-recovery coke ovens.
NOx concentrations in the coke oven exhaust gas emissions will not exceed 20 parts per million (ppm). By comparison, the NOx concentrations in typical automobile vehicle emissions can range from 100 to 2000 ppm.
Volatile Organic Compounds - VOC
The common waste gas-collecting duct also serves as an afterburner tunnel that has been approved by Ohio EPA as BACT for destruction of volatile organic compounds (VOCs) from the non-recovery coke ovens.
VOC concentrations in coke oven exhaust gas emissions will not exceed 1 part per million (ppm). By comparison, the indoor VOC concentrations in typical new construction can range have been found to be as high as 5 ppm.
Hazardous Air Pollutants
The non-recovery coking process is the USEPA's new source maximum achievable control technology (MACT) standard for hazardous air pollutant (HAP) emissions from coke oven batteries. As a result, new byproduct coke oven plants are no longer built within the US.
Based on USEPA information, organic HAP emissions for the FDS Coke Plant are estimated to be less than 5% of the emission rate for existing US byproduct coke plants. Therefore, coke produced by the FDS Coke Plant will reduce organic HAP emissions by an estimated 236,000 lbs when compared to the same coke produced by existing US merchant byproduct plants.
Non-organic HAPs emissions such as metals are further controlled by the SDA and Baghouse used for the main waste gas stream. In addition, technological innovations incorporated in the design of the FDS Coke Plant further reduce HAP emissions from current coke industry standards. For example, the stamped coal charge in combination with the non-recovery oven optimizes the coal carbonization process. This optimization promotes even heating of the coal in the oven and eliminates organic HAP emissions from "green coke" pushes that are an operational problem with byproduct and some non-recovery coke batteries.
Mercury emissions from the FDS Coke Plant will be reduced by two air pollution control technologies. First, the FGD system will reduce mercury emissions from about 15% to 30% based on testing conducted at other non-recovery coke plants in 2006. Second, the FDS Coke Plant will incorporate activated carbon (AC) injection as a mercury-specific air emission control to remove additional mercury to the extent technically and economically feasible.
The AC injection system will consist of a large storage silo, two volumetric feeders, two 100% capacity air blowers with piping and eductors to pneumatically convey the powered AC to injection ports upstream of the SDA vessels.
AC injection is considered the best available technology for the control of mercury air emissions from non-recovery coke batteries. Non-recovery coking plants currently operating in the US are not required to use AC injection to reduce emissions of mercury. Therefore, the FDS Coke Plant will be one of the first to use this technology in the US .
By using AC injection, the FDS Project's anticipated mercury air emissions will be lower on a per MegaWatt-hour basis than USEPA's New Source Performance Standards (NSPS) limits for mercury emissions from new electric utility subbituminous coal-fired boilers.
Particulate Matter - PM
The FDS Project's particulate matter (PM) emissions (including PM10 and PM2.5) will be controlled with a variety of approaches and equipment. All of these approaches and equipment meet or exceed Ohio EPA-approved BACT and BAT requirements.
Summary of PM APC for FDS Project
|Coke Ovens - Coking Process ||High-Efficiency Multiple Compartment Fabric Filter with Leak Detection |
|Charging ||Flat Coal Charging with Traveling Hood and Fabric Filter Baghouse |
|Pushing ||Flat pushing with traveling hood and Fabric Filter Baghouse |
|Quenching ||Baffles and Clean Water |
|Crushing / Screening Operation ||Fully Enclosed Building + Fabric Filter |
|Rail Car Coal Unloading ||Fully Enclosed and Inside |
|Coal Conveying ||Fully Enclosed |
|Coal Storage Pile and Loading ||Minimum Drop / Wet |
|Coke Pile and Loading ||Partially Enclosed or Wet or PE/Chute |
|Coke Yard Conveying ||FE + Inside, PE + Inside, or PE |
|Coke Breeze and Nut Coke Storage and Loading ||PE, FE Hopper, or PE/Chute |
|Cooling Towers ||High Efficiency Mist Eliminator & TDS Water Limitation |
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Green House Gases (GHG)
Although not currently regulated, increasing public concerns regarding global warming have focused increased attention on the emissions of green house gases (GHGs) from industrial operations and electric utility plants. GHGs include carbon dioxide (CO2 ) and other compounds such as methane.
The FDS Coke Plant will have a GHG emission rate of less 5% of existing byproduct coke plants. Based on this huge difference, coke produced by the FDS Coke Plant will reduce GHG emissions by an estimated 30 million tons when compared to the same amount of coke produced by an existing US merchant byproduct plant.
The annual 1 million MWhrs of electricity to be generated by the FDS Project will be produced with no additional GHG emissions. According to the US General Accounting Office, 1 million MWhrs of electricity from a coal-fired power plant would result in annual emissions of 1 million tons of C02.