**Table 4-2**

**F3 SCR**  **Technology Impact Factors for SCR Coal Type**  **F3 SCR**  PRB 0.17 Other Coals 1 (no data available)**Table 4-3**

**Summary**

**of F2 Factors for A ir Heater Removal of Sulfuric A**  **cid Boiler Ty** **pe Fuel**  **F2 Comment**  All Boilers Low S Eastern Bit 0.5 Average of measurements at 7 units. All Boilers Med-High S Eastern Bit (S >2.5%) 0.85 Two data points only. All Boilers PRB 0.36 Based on one data point.

**Table 4-4 Summary** 

**of F2 Factors for Particulate Control Devices (ESP, Baghouse) Equipment Ty** **pe Coal Ty** **pe F2 Factor**  **Comment or Observation** Cold-side ESP Low S Eastern Bit 0.63 Average of measurements at 4 units. Cold-side ESP High S Eastern Bit (>2.5%) 0.77 Average of measurements at 3 units. Cold-side ESP Subbituminous (PRB) 0.72 Based on one measurement at one unit. Hot-side ESP All 0.63 Based on one measurement at one unit. Baghouse Subbituminous coal 0.1 Two data points.

**Table 4-5 Summary** 

**of F2 Factors for Wet, Dry FGD Equipment and A**  **dditives**

**FGD Ty pe**  **Coal Ty pe**  **F2 Factor Comment or Observation**  Wet: Spray Tower E. Bituminous 0.47 Seven data points. Wet: Spray Tower PRB or Lignite 0.4 Two data points. Wet: Venturi Tower All coals 0.65 Based on bituminous coal only; limited data merit assigning same factor for other coals. Dry FGD and baghouse All coals 0.01 Two data points. Mg-Ox mixed w/fuel oil All fuel 0.5 One data point. Mg-Ox into furnace All fuel 0.5 One data point.**Table 4-1**

**Summary**

**of Fuel Impact Factors (F1) for Steam Generating Units Fuel**  **Equipment F1**  **Comment**

Med-High S Eastern Bituminous (>2.5%) Dry Bottom Boiler 0.011 Seven data points.

Med-High S Eastern Bituminous (>2.5%) Cyclone 0.016 One data point.

Low S Eastern Bit. Dry Bottom Boiler 0.0082 Average of measurements at 16 units; slight increase in penetration compared to Harrison (2005). W.Bituminous Dry Bottom Boiler 0.00111 One data point. W.Bituminous Cyclone 0.0022 One data point.

Subbituminous/PRB All Boilers 0.0019 Average of 7 units; an increase in penetration compared to Harrison (2005). Lignite Dry Bottom Boiler 0.0044 One data point. Lignite Cyclone 0.00112 One data point. Petroleum coke Boiler 0.04 One data point. Natural gas Boiler 0.01 #2 Fuel oil Boiler 0.01 #6 Fuel oil Boiler 0.025 Used oil Boiler 0.0175

Natural gas CT See Table 6- 1

#2 Fuel oil CT See Table 6- 1 Natural gas CC 0.0555 #2 Fuel oil CC 0.0555 New category in 2007. Other Alternative Fuels Any 0.04 Other Alternative Fuels, co-fired w/coal, >75% heat throughput NA Use Coal F1, in absence of any applicable data.**EM Comb = K • F1 • E2** 

**K =** 3063 lb H2SO4/ton SO2 F1 = 0.0019 Fuel Impact Factor from F1 table

**Equation 4-2b E2 = K1** • **K2** • **C1** • **S1** C1 = 500 Coal burn, tons/hr S1 = 0.27 Coal sulfur weighted average, % K1 = 0.02 ton SO2/%S K2 = 0.875 0.95 for bituminous coals 0.875 for subbituminous coals = 0.55 to 0.85 for lignite, based on the Na content 1.0 for oil **E2 =** K1 • K2 • C1 • S1 **E2 =** 0.02 * 0.875 * 500 * 0.27 **E2 =** 2 SO2 mass rate, tons/hr

**EM Comb =**  K * F1 * E2 **EM Comb =**  3063 * 0.0019 * 2 **EM Comb =**  13.75 total H2SO4 manufactured from combustion, lbs/hr

**Sulfuric Acid Released from Combustion (ERComb) Equation 4-3 ERComb = EMComb**  • **F2 (all that apply) ERComb =**  EMCom b • F2 (AH) • F2 (PM) • F2 (FGD) **ERComb =** 14 * 0.36 * 0.72 * 1 **ERComb =** 3.56 total H2SO4 released from combustion, lbs/hr

**Sulfuric Acid M**

**anufacture by SCR (EM SCR)**  **EM SCR = K**  • **S2** • **fsops** • **E2**• **F3SCR** = Total H2SO4 manufactured from SCR, lbs per hour K = 3063 lb H2SO4/ton SO2 S2 = 0.005 SCR catalyst SO2 oxidation rate (specified as a decimal, typically from 0.001- 0.03) fsops = 1 for continuous operation E2 = 2 SO2 produced, tons per hour F3SCR = 1 Technology Impact Factor, for SCR Table 4-2 **EM SCR =**  K • S2 • fsops • E2 • F3SCR **EM SCR =**  3063 * 0.005 * 1 * 2 * 1 **EM SCR =**  36.18 = Total H2SO4 manufactured from SCR, lbs per hour**Equation 4-11a: Manufacture**

**TSA M = EMComb + EMSCR/SNCR +**  **TSA M =**  EMCom b + EMSCR/SNCR + EMFGC **TSA M =**  14 + 36 **TSA M =**  49.93 = Total H2SO4 manufactured, lbs per hour

**Sulfuric Acid Released from SCR and SNCR Equation 4-5 ERSCR = [EMSCR – (Ks**  • **B** • **fsreagent** • **SNH3)]** • **F2x** ERSCR = Total H2SO4 released from SCR, lbs per hour EMSCR = Total H2SO4 manufactured from SCR, lbs per hour Ks = 3799 Conversion factor HV = 8,950 Btu/lb B = 8.95E-03 Coal burn in TBtu/hr fsreagent = 1 fraction of SCR operation with reagent injection SNH3 = 2 NH3 slip from SCR/SNCR, ppmv at 6% O2, wet • SCR averages 0.75 ppmv over catalyst guarantee period • SNCR averages 5 ppmv • Note: actual NH3 slip data should be used if available F2x = Technology Impact Factors, all that apply **ERSCR =** [ EMSCR – ( Ks • B • fsreagent • SNH3 )] • F2 (AH) • F2 (PM) • **ERSCR =** ( 36 – ( 3799 * 8.95E-03 * 1 * 2 ))* 1 * 0.63 * **ERSCR =** ( 36 – ( 6.80E+01 ))* 0.2961 **ERSCR =** -3.18E+01 * 0.2961 **ERSCR =** (9.42) Total H2SO4 released from SCR, lbs per hour

**Equation 4-11b: Release TSA** **R = ERComb + ERSCR/SNCR + ERFGC TSA** **R =** ERComb + ERSCR/SNCR + ERFGC **TSA R =**  3.56 + (9.42) + **TSA R =**  (5.86) Total H2SO4 released, lbs per hourF2 (FGD)

0.47**Given/A ssume** 

**Combustion** Enter Value C1 = 500 Coal burn, tons/hr HV = 8,950 Btu/lb S1 = 0.27 Coal sulfur weighted average, %

K2 = 0.875 0.95 for bituminous coals 0.875 for subbituminous coals = 0.55 to 0.85 for lignite, based on the Na content 1.0 for oil

F1 = 0.0019 Fuel Impact Factor from F1 table

F2 (AH) = 0.36 Technology Impact Factor from F2 tables If not applicable, enter "1". F2 (PM) = 0.72 Technology Impact Factor from F2 tables If not applicable, enter "1". F2 (FGD) = 1 Technology Impact Factor from F2 tables If not applicable, enter "1".

**For SCR**S2 = 0.005 SCR catalyst SO2 oxidation rate (specified as a decimal, typically from 0.001- 0.03) fsops = 1 portion of time that SCR is in use F2 (AH) = 1 Technology Impact Factor from F2 tables If not applicable, enter "1". F2 (PM) = 0.63 Technology Impact Factor from F2 tables If not applicable, enter "1". F2 (FGD) = 0.47 Technology Impact Factor from F2 tables If not applicable, enter "1".

F3SCR = 1 **Technology Impact Factors for SCR Coal Type**  **F3SCR** PRB 0.17 Other Coals 1 (no data available)

fsreagent = 1 fraction of operation with reagent injection SNH3 = 2 NH3 slip from SCR/SNCR, ppmv at 6% O2, wet**Equation 4-1 EMComb = K** • **F1** • **E2**

where, EMCom b= total H2SO4 manufactured from combustion, lbs/yr K = Molecular weight and units conversion constant, equal to 3,063. This value is derived as follows: 98.07/64.04 • 2000 = 3,063. Here, 98.07 is the molecular weight of H2SO4; 64.04 is the molecular weight of SO2; conversion from tons per year to pounds per year requires multiplying by 2000. F1 = Fuel Impact Factor E2 = Sulfur dioxide (SO2) em issions, either: (1) recorded by a continuous em issions monitor, tons/yr, or (2) calculated from coal burn data, tons/yr.

When any source uses FGD equipment or another technology to control SO2 em issions, either the fuel basis **must** be used for the manufacturing and release calculations, or CEMS data can be used but only when the CEMS precedes the FGD or SO2 control equipment. **CEM S**  **data after**  **a flue**  **gas desulfurization**  **system cannot**  **be used.** 

As an alternative to using CEMS data, the following relationship based on coal burn data can be used to estimate the rate of SO2 emissions: **Equation 4-2b E2 = K1** • **K2** • **C1** • **S1** where, E2 = SO2 mass rate, tons/yr C1 = Coal burn, tons/yr S1 = Coal sulfur weighted average, % K1 = Molecular weight and units conversion constant, equal to 0.02. This value is derived from (64.04)/(100 • 32.06) = 0.02. Here, 64.04 is the molecular weight of SO2; 32.06 is the molecular weight of S; and conversion of % S to a fraction requires multiplying by 100. K2 = Sulfur conversion to SO2, implicit from EPA AP-42 (EPA, 1995b) = 0.95 for bituminous coals = 0.875 for subbituminous coals = 0.55 to 0.85 for lignite, based on the Na content = 1.0 for oil

**Sulfuric Acid Released from Combustion (ERComb)** For units that do not em ploy SCR or SNCR NOx control or FGC, the sulfuric acid released is the product of the

amount manufactured and the Technology Impact Factors (F2) for all downstream equipment (the air heater, the particulate control device, the FGD, etc.). For these units, the total sulfuric acid em issions can be calculated from Equation 4-3. **Equation 4-3 ERComb = EMComb** • **F2 (all that apply) Sulfuric Acid M**  **anufacture by SCR (EM SCR)**  The following relationship estimates the total H2SO4 manufactured from an SCR equipped utility boiler or steam generator: **Equation 4-4 EMSCR = K** • **S2** • **fsops** • **E2**• **F3SCR** where, EMSCR = Total H2SO4 manufactured from SCR, lbs per year K = Conversion factor = 3063 S2 = SCR catalyst SO2 oxidation rate (specified as a decimal, typically from 0.001- 0.03)

fsops = Operating factor of SCR system, or the fraction of coal burn when the flue gas is directed through the SCR, whether NH3 reagent is injected to derive NOx reduction or not. This value should reflect the hours the SCR reactor processed flue gas, which will be site-specific but can be approximated by generally 0.8 for year-round peaking operation, 0.98 for year-round base-loaded operation, or 0.43 for seasonal operation E2 = SO2 produced, tons per year F3SCR = Technology

Impact Factor, for SCR

An F3SCR factor for PRB coals is shown in Table 4-2. This factor is derived from measurements at two PRB-fired units. SO3 em itted from these units was lower than specified in the catalyst guarantee, which was based on laboratory test data. At present, there are no data to support F3SCR factors for other coals, so a factor of 1 (full penetration) is recommended.

**Table 4-2 F3SCR Technology Impact Factors for SCR**  **Coal Type F3SCR**  PRB 0.17 Other Coals 1 (no data available)

**Sulfuric Acid Released from SCR and SNCR** The sulfuric acid released from SCR or SNCR is determined by subtracting from the sulfuric acid manufactured the

amount removed by the residual am monia, or am monia slip. For SCR, the sulfuric acid released (ERSCR) is estimated with the following relationship: **Equation 4-5 ERSCR = [EMSCR – (Ks** • **B** • **fsreagent** • **SNH3)]** • **F2x** where, ERSCR = Total H2SO4 released from SCR, lbs per yearEMSCR = Total H2SO4 manufactured from SCR, lbs per year

Ks = Conversion factor = 3799 B = Coal burn in TBtu/yr
fsreagent = fraction of SCR operation with reagent injection, when residual NH3 is produced that will remove SO3. The value of fsreagent will be similar to, but slightly less than, the value of fsops, defined for Equation 4-4. SNH3 = NH3 slip from SCR/SNCR, ppmv at 6% O2, wet: • SCR averages 0.75 ppmv over catalyst guarantee period • SNCR averages 5 ppmv • Note: actual NH3 slip data should be used if available F2x = Technology

Impact Factors, all that apply The conversion factor Ks, equal to 3799, considers all relevant constants to yield the result in pounds per year of sulfuric acid. The derivation of this constant, for the case where residual NH3 is reported in terms of 6% oxygen and “wet” flue gas at 8.1% H2O, is presented in Text Box B. The coal burn rate in TBtu/yr is obtained from coal use records, such as those reported to EIA in Form 767. The operating factor of the SCR describes the portion of the coal burn that reflects the period of SCR operation, based

on whether the unit operates seasonally (0.43), annually in a base-load duty (0.98), or annually in peaking duty (0.80).

Accordingly

, total sulfuric acid manufacture (TSAM) and release (TSAR) is estimated for agenerating unit equipped with SCR and flue gas conditioning by the following equations: **Equation 4-11a: Manufacture TSA** **M = EMComb + EMSCR/SNCR + EMFGC Equation 4-11b: Release**  **TSA R = ERComb + ERSCR/SNCR + ERFGC**