X continuous emission monitoring system no later than the applicable deadline specified in § 75.4. Apply to the Administrator for certification to use this method no later than 45 days after the completion of all certification testing. Whenever the monitoring method is to be changed, reapply to the Administrator for certification of the new monitoring method.
1.2.2 If the owner or operator has already successfully completed certification testing of the unit using the protocol of appendix E of part 75 and submitted a certification application under § 75.20(g) prior to ____ July 17, 1995, the unit's monitoring system does not need to repeat initial certification testing using the revised procedures published ____ May 17, 1995.
2. Procedure
2.1 Initial Performance Testing
Use the following procedures for: measuring NOX emission rates at heat input rate levels corresponding to different load levels; measuring heat input rate; and plotting the correlation between heat input rate and NOX emission rate, in order to determine the emission rate of the unit(s).
2.1.1 Load Selection
Establish at least four approximately equally spaced operating load points, ranging from the maximum operating load to the minimum operating load. Select the maximum and minimum operating load from the operating history of the unit during the most recent two years. (If projections indicate that the unit's maximum or minimum operating load during the next five years will be significantly different from the most recent two years, select the maximum and minimum operating load based on the projected dispatched load of the unit.) For new gas-fired peaking units or new oil-fired peaking units, select the maximum and minimum operating load from the expected maximum and minimum load to be dispatched to the unit in the first five calendar years of operation.
2.1.2 NOX and O2 Concentration Measurements
Use the following procedures to measure NOX and O2 concentration in order to determine NOX emission rate.
2.1.2.1 For boilers, select an excess O2 level for each fuel (and, optionally, for each combination of fuels) to be combusted that is representative for each of the four or more load levels. If a boiler operates using a single, consistent combination of fuels only, the testing may be performed using the combination rather than each fuel. If a fuel is combusted only for the purpose of testing ignition of the burners for a period of five minutes or less per ignition test or for start-up, then the boiler NOX emission rate does not need to be tested separately for that fuel. Operate the boiler at a normal or conservatively high excess oxygen level in conjunction with these tests. Measure the NOX and O2 at each load point for each fuel or consistent fuel combination (and, optionally, for each combination of fuels) to be combusted. Measure the NOX and O2 concentrations according to method 7E and 3A in appendix A of part 60 of this chapter. Select sampling points as specified in section 5.1, method 3 in appendix A of part 60 of this chapter. The designated representative for the unit may also petition the Administrator under § 75.66 to use fewer sampling points. Such a petition shall include the proposed alternative sampling procedure and information demonstrating that there is no concentration stratification at the sampling location.
2.1.2.2 For stationary gas turbines, select sampling points and measure the NOX and O2 concentrations at each load point for each fuel or consistent combination of fuels (and, optionally, each combination of fuels) according to appendix A, method 20 of part 60 of this chapter. For diesel or dual fuel reciprocating engines, measure the NOX and O2 concentrations according to method 20, but modify method 20 by selecting a sampling site to be as close as practical to the exhaust of the engine.
2.1.2.3 Allow the unit to stabilize for a minimum of 15 minutes (or longer if needed for the NOX and O2 readings to stabilize) prior to commencing NOx, O2, and heat input measurements. Determine the average measurement system response time according to section 5.5 of method 20 in appendix A, part 60 of this chapter. When inserting the probe into the flue gas for the first sampling point in each traverse, sample for at least one minute plus twice the average measurement system response time (or longer, if necessary to obtain a stable reading). For all other sampling points in each traverse, sample for at least one minute plus the average measurement response time (or longer, if necessary to obtain a stable reading). Perform three test runs at each load condition and obtain an arithmetic average of the runs for each load condition. During each test run on a boiler, record the boiler excess oxygen level at 5 minute intervals.
2.1.3 Heat Input
Measure the total heat input (mmBtu) and heat input rate during testing (mmBtu/hr) as follows:
2.1.3.1 When the unit is combusting fuel, measure and record the flow of fuel consumed. Measure the flow of fuel with an in-line flowmeter(s) and automatically record the data. If a portion of the flow is diverted from the unit without being burned, and that diversion occurs downstream of the fuel flowmeter, an in-line flowmeter is required to account for the unburned fuel. Install and calibrate in-line flow meters using the procedures and specifications contained in sections 2.1.2, 2.1.3, 2.1.4, and 2.1.5 of appendix D of this part. Correct any gaseous fuel flow rate measured at actual temperature and pressure to standard conditions of 68 °F and 29.92 inches of mercury.
2.1.3.2 For liquid fuels, analyze fuel samples taken according to the requirements of section 2.2 of appendix D of this part to determine the heat content of the fuel. Determine heat content of liquid or gaseous fuel in accordance with the procedures in appendix F of this part. Calculate the heat input rate during testing (mmBtu/hr) associated with each load condition in accordance with equations F-19 or F-20 in appendix F of this part and total heat input using equation E-1 of this appendix. Record the heat input rate at each heat input/load point.
2.1.4 Emergency Fuel
The designated representative of a unit that is restricted by its Federal, State or local permit to combusting a particular fuel only during emergencies where the primary fuel is not available may petition the Administrator pursuant to the procedures in § 75.66 for an exemption from the requirements of this appendix for testing the NOX emission rate during combustion of the emergency fuel. The designated representative shall include in the petition a procedure for determining the NOX emission rate for the unit when the emergency fuel is combusted, and a demonstration that the permit restricts use of the fuel to emergencies only. The designated representative shall also provide notice under § 75.61(a) for each period when the emergency fuel is combusted.
2.1.5 Tabulation of Results
Tabulate the results of each baseline correlation test for each fuel or, as applicable, combination of fuels, listing: time of test, duration, operating loads, heat input rate (mmBtu/hr), F-factors, excess oxygen levels, and NOX concentrations (ppm) on a dry basis (at actual excess oxygen level). Convert the NOX concentrations (ppm) to NOX emission rates (to the nearest 0.01 lb/mm/Btu) according to equation F-5 of appendix F of this part or 19-3 in method 19 of appendix A of part 60
of this chapter, as appropriate. Calculate the NOX emission rate in lb/mmBtu for each sampling point and determine the arithmetic average NOX emission rate of each test run. Calculate the arithmetic average of the boiler excess oxygen readings for each test run. Record the arithmetic average of the three test runs as the NOX emission rate and the boiler excess oxygen level for the heat input/load condition.
2.1.6 Plotting of Results
Plot the tabulated results as an x-y graph for each fuel and (as applicable) combination of fuels combusted according to the following procedures.
2.1.6.1 Plot the heat input rate (mmBtu/hr) as the independent (or x) variable and the NOX emission rates (lb/mmBtu) as the dependent (or y) variable for each load point. Construct the graph by drawing straight line segments between each load point. Draw a horizontal line to the y-axis from the minimum heat input (load) point.
2.1.6.2 Units that co-fire gas and oil may be tested while firing gas only and oil only instead of testing with each combination of fuels. In this case, construct a graph for each fuel.
2.2 Periodic NOx Emission Rate Testing
Retest the NOx emission rate of the gas-fired peaking unit or the oil-fired peaking unit prior to the earlier of 3,000 unit operating hours or the 5-year anniversary and renewal of its operating permit under part 72 of this chapter.
2.3 Other Quality Assurance/Quality Control-Related NOx Emission Rate Testing
When the operating levels of certain parameters exceed the limits specified below, or where the Administrator issues a notice requesting retesting because the NOX emission rate data availability for when the unit operates within all quality assurance/quality control parameters in this section since the last test is less than 90.0 percent, as calculated by the Administrator, complete retesting of the NOX emission rate by the earlier of: (1) 10 unit operating days (as defined in section 2.1 of appendix B of this part) or (2) 180 calendar days after exceeding the limits or after the date of issuance of a notice from the Administrator to re-verify the unit's NOX emission rate. Submit test results in accordance with § 75.60(a) within 45 days of completing the retesting.
2.3.1 For a stationary gas turbine, obtain a list of at least four operating parameters indicative of the turbine's NOX formation characteristics, and the recommended ranges for these parameters at each tested load-heat input point, from the gas turbine manufacturer. If the gas turbine uses water or steam injection for NOX control, the water/fuel or steam/fuel ratio shall be one of these parameters. During the NOx-heat input correlation tests, record the average value of each parameter for each load-heat input to ensure that the parameters are within the manufacturer's recommended range. Redetermine the NOX emission rate-heat input correlation for each fuel and (optional) combination of fuels after continuously exceeding the manufacturer's recommended range of any of these parameters for one or more successive operating periods totaling more than 16 unit operating hours.
2.3.2 For a diesel or dual-fuel reciprocating engine, obtain a list of at least four operating parameters indicative of the engine's NOX formation characteristics, and the recommended ranges for these parameters at each tested load-heat input point, from the engine manufacturer. Any operating parameter critical for NOX control shall be included. During the NOX heat-input correlation tests, record the average value of each parameter for each load-heat input to ensure that the parameters are within the manufacturer's recommended range. Redetermine the NOX emission rate-heat input correlation for each fuel and (optional) combination or fuels after continuously exceeding the manufacturer's recommended range of any of these parameters for one or more successive operating periods totaling more than 16 unit operating hours.
2.3.3 For boilers using the procedures in this appendix, the NOX emission rate heat input correlation for each fuel and (optional) combination of fuels shall be redetermined if the excess oxygen level at any heat input rate (or unit operating load) continuously exceeds by more than 2 percentage points O2 from the boiler excess oxygen level recorded at the same operating heat input rate during the previous NOX emission rate test for one or more successive operating periods totaling more than 16 unit operating hours.
2.4 Procedures for Determining Hourly NOX Emission Rate
2.4.1 Record the time (hr. and min.), load (MWge or steam load in 1000 lb/hr), fuel flow rate and heat input rate (using the procedures in section 2.1.3 of this appendix) for each hour during which the unit combusts fuel. Calculate the total hourly heat input using equation E-1 of this appendix. Record the heat input rate for each fuel to the nearest 0.1 mmBtu/hr. During partial unit operating hours or during hours where more than one fuel is combusted, heat input must be represented as an hourly rate in mmBtu/hr, as if the fuel were combusted for the entire hour at that rate (and not as the actual, total heat input during that partial hour or hour) in order to ensure proper correlation with the NOX emission rate graph.
2.4.2 Use the graph of the baseline correlation results (appropriate for the fuel or fuel
combination) to determine the NOX emissions rate (lb/mmBtu) corresponding to the heat input rate (mmBtu/hr). Input this correlation into the data acquisition and handling system for the unit. Linearly interpolate to 0.1 mmBtu/hr heat input rate and 0.01 lb/mmBtu NOX (0.001 lb/mmBtu NOX after April 1, 2000). For each type of fuel, calculate NOX emission rate using the baseline correlation results from the most recent test with that fuel, beginning with the date and hour of the completion of the most recent test.
2.4.3 To determine the NOX emission rate for a unit co-firing fuels that has not been tested for that combination of fuels, interpolate between the NOX emission rate for each fuel as follows. Determine the heat input rate for the hour (in mmBtu/hr) for each fuel and select the corresponding NOX emission rate for each fuel on the appropriate graph. (When a fuel is combusted for a partial hour, determine the fuel usage time for each fuel and determine the heat input rate from each fuel as if that fuel were combusted at that rate for the entire hour in order to select the corresponding NOX emission rate.) Calculate the total heat input to the unit in mmBtu for the hour from all fuel combusted using Equation E-1. Calculate a Btu-weighted average of the emission rates for all fuels using Equation E-2 of this appendix. For each type of fuel, calculate NOX emission rate using the baseline correlation results from the most recent test with that fuel, beginning with the date and hour of the completion of the most recent test.
2.4.4 For each hour, record the critical quality assurance parameters, as identified in the monitoring plan, and as required by section 2.3 of this appendix from the date and hour of the completion of the most recent test for each type of fuel.
2.5 Missing Data Procedures
Provide substitute data for each unit electing to use this alternative procedure whenever a valid quality-assured hour of NOX emission rate data has not been obtained according to the procedures and specifications of this appendix.
2.5.1 Use the procedures of this section whenever any of the quality assurance/quality control parameters exceeds the limits in section 2.3 of this appendix or whenever any of the quality assurance/quality control parameters are not available.
2.5.2 Substitute missing NOX emission rate data using the highest NOX emission rate tabulated during the most recent set of baseline correlation tests for the same fuel or, if applicable, combination of fuels.
2.5.3 Maintain a record indicating which data are substitute data and the reasons for the failure to provide a valid quality-assured hour of NOX emission rate data according to the procedures and specifications of this appendix.
2.5.4 Substitute missing data from a fuel flowmeter using the procedures in section 2.4.2 of appendix D to this part.
2.5.5 Substitute missing data for gross calorific value of fuel using the procedures in sections 2.4.1 of appendix D to this part.
3. Calculations
3.1 Heat Input
Calculate the total heat input by summing the product of heat input rate and fuel usage time of each fuel, as in the following equation:
View or Download PDF
Where:
HT = Total heat input of fuel flow or a combination of fuel flows to a unit, mmBtu.
HIfuel 1,2,3,...last = Heat input rate from each fuel, in mmBtu/hr as determined using Equation F-19 or F-20 in section 5.5 of appendix F to this part, mmBtu/hr.
t1,2,3....last = Fuel usage time for each fuel (rounded up to the nearest fraction of an hour (in equal increments that can range from one hundredth to one quarter of an hour, at the option of the owner or operator)).
3.1 Heat Input
Calculate the total heat input by summing the product of heat input rate and fuel usage time of each fuel, as in the following equation:
HT = HIfuel1 t1 + HIfuel2 t2 + HIfuel3 t3 + . . . + HIlastfuel tlast
(Eq. E-1)
where:
HT = Total heat input of fuel flow or a combination of fuel flows to a unit, mmBtu;
HIfuel1,2,3,...last = Heat input rate from each fuel during fuel usage time, in mmBtu/hr, as determined using equation F-19 or F-20 in section 5.5 of appendix F of this part, mmBtu/hr;
t1,2,3....last = Fuel usage time for each fuel, rounded up to the nearest .25 hours.
Note:
For hours where a fuel is combusted for only part of the hour, use the fuel flow
rate or mass flow rate during the fuel usage time, instead of the total fuel flow during the hour, when calculating heat input rate using equation F-19 or F-20.
3.2 F-factors
Determine the F-factors for each fuel or combination of fuels to be combusted according to section 3.3 of appendix F of this part.
3.3 NOX Emission Rate
3.3.1 Conversion from Concentration to Emission Rate
Convert the NOX concentrations (ppm) and O2 concentrations to NOX emission rates (to the nearest 0.01 lb/mmBtu for tests performed prior to April 1, 2000, or to the nearest 0.001 lb/mmBtu for tests performed on and after April 1, 2000), according to the appropriate one of the following equations: F-5 in appendix F to this part for dry basis concentration measurements or 19-3 in Method 19 of appendix A to part 60 of this chapter for wet basis concentration measurements.
3.3.2 Quarterly Average NOX Emission Rate
Report the quarterly average emission rate (lb/mmBtu) as required in subpart G of this part. Calculate the quarterly average NOX emission rate according to equation F-9 in appendix F of this part.
3.3.3 Annual Average NOX Emission Rate
Report the average emission rate (lb/mmBtu) for the calendar year as required in subpart G of this part. Calculate the average NOX emission rate according to equation F-10 in appendix F of this part.
3.3.4 Average NOX Emission Rate During Co-firing of Fuels
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Where:
Eh = NOX emission rate for the unit for the hour, lb/mmBtu.
Ef = NOX emission rate for the unit for a given fuel at heat input rate HIf, lb/mmBtu.
HIf = Heat input rate for the hour for a given fuel, during the fuel usage time, as determined using Equation F-19 or F-20 in section 5.5 of appendix F to this part, mmBtu/hr.
HT = Total heat input for all fuels for the hour from Equation E-1.
tf = Fuel usage time for each fuel (rounded up to the nearest fraction of an hour (in equal increments that can range from one hundredth to one quarter of an hour, at the option of the owner or operator)).
Note:
For hours where a fuel is combusted for only part of the hour, use the fuel flow rate or mass flow rate during the fuel usage time, instead of the total fuel flow or mass flow during the hour, when calculating heat input rate using Equation F-19 or F-20.
4. Quality Assurance/Quality Control Plan
Include a section on the NOX emission rate determination as part of the monitoring quality assurance/quality control plan required under § 75.21 and appendix B of this part for each gas-fired peaking unit and each oil-fired peaking unit. In this section present information including, but not limited to, the following: (1) a copy of all data and results from the initial NOX emission rate testing, including the values of quality assurance parameters specified in section 2.3 of this appendix; (2) a copy of all data and results from the most recent NOX emission rate load correlation testing; (3) a copy of the unit manufacturer's recommended range of quality assurance- and quality control-related operating parameters.
4.1 Submit a copy of the unit manufacturer's recommended range of operating parameter values, and the range of operating parameter values recorded during the previous NOX emission rate test that determined the unit's NOX emission rate, along with the unit's revised monitoring plan submitted with the certification application.
4.2 Keep records of these operating parameters for each hour of operation in order to demonstrate that a unit is remaining within the manufacturer's recommended operating range.
[58 FR 3701, Jan. 11, 1993, as amended at 60 FR 26551-26553, May 17, 1995; 64 FR 28665, May 26, 1999]
