Jon Konings Former CEM Coordinator
Not covering every detail of these QA topics. There is such a wide variation in the configuration of hardware out there, and I can t cover everything, so I will address general terms and issues. I don t have all the answers, but I hope I can open your eyes and help you be better prepared and ready for success. 2
This protocol is only available to Gas fired peaking * units, or Oil fired peaking * units * Peaking units are those units with an: Average capacity factor of not more than 10% over the past 3 years, and Of those three years, no one year can have a capacity factor of > 15%. Units which have low capacity factors also have low total mass emissions for the year. Capacity factor = total actual accumulated annual load/total maximum hourly load times 8760 Each year the operator must update the Qualification Record for peaking status with either actual historical capacity data or projected capacity data. 3
Appendix E is based on the alternate way to calculate heat input from Appendix D, and then to indirectly to calculate an hourly NOx emission rate, based on previous testing. The NOx estimation protocol replaces operating NOx & O2/CO2 monitors. The hourly heat input value from Appendix D is extended to and used by the Appendix E protocol. Through NOx testing at four different operating levels, a response curve is developed of heat input versus NOx emission rate. After testing, the calculated hourly heat input value is used with the correlation curve to estimate the hourly NOx emission rate. Let s look at a sample Heat Input vs. NOx lb./mmbtu curve. 4
5
Notice the four different operating levels. The curve extends horizontally from the lowest testing level to the zero heat input on the X axis. And notice the highest operating level (level 4). We use the hourly heat input (MMBtu/hr.) to calculate or predict a NOx emission rate (NOx lb./mmbtu). This is an example of a PEMS Predictive Emission Monitoring System 6
I recommend that the Appendix E reporting protocol should only be used for P75 reporting purposes. We have seen a few reporting conditions outside of P75 where NOx correlation was allowed but ran into issues when the missing data values reported lead to exceedances. The NOx hourly averages were not intended to be used in extended averages, like 3-hour or 24 hour averages. For Appendix E, special missing data algorithms for: missing fuel flow periods, i.e. no hourly heat input. When the hourly heat input readings are higher than the highest heat input testing level (can be up to 1.25 times the highest NOx rate tested or up to MER. When one of the operating quality assurance parameters are missing 7
First, the NOx Correlation module must be enabled after purchasing. It s special software. The On-line Help for Appendix E information in SV Past NOx Correlation records found in StackVision Part 75 Policy Manual Section 24 Appendix E Plain English Guide to Part 75 Rule really good https://www.epa.gov/airmarkets/clean-air-marketsemissions-monitoring 8
1. Launching the NOx Correlation feature- Tools > QA and Certification > NOx Correlation 2. Adding a NOx Correlation Record a 5 step wizard to step up the record 3. Importing a NOx Correlation Record a 5 step wizard for importing older flat-file EDRs. 4. Selecting Protocol Gas Certificates- these are the cylinders the stack testers used on their monitors. They must be loaded into Cal Gas Management module first. 5. Entering AETB Data this info can be imported via Excel template that can be exported from SV first. 9
6. Associating AETB Data with a NOx Correlation test a six step process. 7. Adding additional Correlated parameters- wizard walk you through the steps will 8. Retrieving Minute Data after each run, the corresponding operating data needs to be retrieved. 9. Calculating the Reference Mean after the NOx lb./mmbtu rates are entered for each run, calculate the reference mean 10. Configuring NOx Correlation alarms review carefully to decide how best to use. 10
In 75.61 (a)(1) addresses initial certification or recertification, and written notification is required, but there are some exceptions, except as provided in paragraphs (a)(1)(iii), (a)(1)iv) and (a)(4) of this section. Read these exceptions carefully. In any case, a courtesy email to the local or state agency outlining your plans for using the Appendix E protocol isn t a bad idea either. They are going to receive your hardcopy certification package down the road for their approval. 11
For initial certification or recertification, a notification is required 21 days prior to the first scheduled day of testing. Check out 75.61 (a)(5) for details about this requirement. This notification process has two parts to it: First, submitting the electronic Monitoring Plan records through ECMPS. Second, submitting a hard copy package, incompatible with the electronic format, consisting of: Copy of the Monitoring Plan records, Test protocols, or many, many other special documents. This hard copy notification package goes to the EPA s regional office and to your local or state environmental agency. On-going retesting for Appendix E also have a 21 notice provision to CAMD, but the regulations allow regulatory agencies to issue a notice waiver. And CAMD has issued a waiver! You need to verify if your state or the regional EPA office has issued a waiver or still requires to be notified. I am not aware of any state having issued a notice waiver. 12
The idea behind the Monitoring Outline is to layout how this alternative or excepted monitoring system will operate. Again, this is not officially required but I used it to prepare this simple outline as the precursor to the QAQC plan. This protocol is a different way, so sit down and think this process through. At a minimum, an outline for Appendix E should include: 1. A description of how the four operating levels will be selected and determined. 2. Which four operating parameters will be used to check the NOx operating conditions 3. How wide the tolerance band is being set for these operating parameters 4. A description of the process for deciding how wide to set these tolerance bands. 5. A statement that the DAHS will follow the Appendix E missing data substitution requirements through StackVision. 13
1. The first step is identify the four operating levels and the sequence of the operating levels is very important. Why? Let s call the four levels the following. Lowest the lowest safe, sustainable and stable operating level, Low-mid, Mid-high, Highest this needs to be the highest, safe and sustainable load achievable today. The lowest level should be tested first, followed by the highest. Extend out the curve as far as possible. Now that you know the top and bottom, select the two mid loads. Break up this gap with the two mid loads equally spaced. 14
1. Here is an example. Say our unit is rated at 100 MWs for it s maximum. Let s call the four levels the following. Lowest level is tested first we are able to hold 40 MWs easily and test there first. Highest level comes next. We manage to hold 97 MWs today and test there next. The gap between highest and lowest is 57MWs. Divide this gap into thirds, or 19 MWs. Low-mid level is tested at 59 MWS (40+19), Mid-high level is tested at 78 MW (59 +19 = 78, or 97-19 = 78). After testing at the lowest and then the highest, the testing sequence for the last two loads isn t as important and you could leave it up to the operator to decide what order he wants. Work with the operators ahead of time to get the load levels you want in the sequence that you want. 15
2. From your in house procedure, identify the four operating parameters than are tracked for NOx emissions. On combustion turbines, if water or steam injection is used, then Appendix E requires that either the injection rate or the fuel-to-water/steam ratio is one of the four operating parameters. For boilers, the excess O2 level must be one of the four operating parameters. These operating parameters control or contribute to the formation of NOx emissions by controlling the combustion process. They might be: Inlet guide vane position, Compressor temperature, Compressor pressure, Outlet temperature, Or other parameters recommended by the OEM (Original Equipment Manufacturer) 16
3. While holding the operating load steady at each of the four levels, the stack testers will use reference methods to measure the NOx ppm concentration and the emission rate in lbs./mmbtu). They must record data for at least three runs at each operating level. Use the Wizard to add a NOx Correlation record. At the Main Menu, select : Tools QA and Certification and then NOx Correlation. Use the Add icon add a new record. In the Wizard screens, you will have to enter or select: When the last test was completed, The reason for the Test, Fuel Flow Measurement Type, Fuel Type, And a lot of other information. Having a written out in-house procedure to follow will make setting up these records much easier, 17
4. While the stack testers were measuring the NOx data, you need to set up the NOx Correlation records to retrieve from the minute database the corresponding information for: Average heat input recorded during each testing run. Average load recorded during each test rim. The average value recorded for each of the four operating parameters during each test run. Since the test runs are not typically an hour long, the actual recorded values will be converted to hourly averages by the NOx correlation utility. This will allow an easy comparison between hourly values recorded after testing is completed to values recorded during the testing, but converted to hourly averages. 18
5. At the Main screen for the NOx Correlation testing, be sure to click on the Associate AETB Qualified Individual(s) button in the toolbar or click the link in the AETB Qualified Individual column. This is the person on-site from the stack testing team who they identified as supervising the stack testing. When an AETB Individual has been successfully added or associated with a particular NOx test, the qualified individual s name should now appear on the NOx Correlation Tests tab in the AETB Qualified Individual column. 6. You also must add or associate the PGVP Certificates for the gas cylinders used by the stack testers to run QA checks on their monitors to the NOx Correlation records. This means those certificates must be entered into the Cal Gas Manager feature of StackVision. 7. Failure to associate an AETB individual or all of the gas certificates will trigger a fatal error when the QA file is evaluated in ECMPS. 19
8. Use the Retrieve minute data feature to fill in the operating data for each run. 9. Use the Calculate command in the toolbar to calculate the reference mean values for heat input (rounded to 1) and NOx rates rounded to three decimal places. 10. During the Calculate process, the heat input value recorded for each run will be converted to an hourly averages so it can be compared against future hourly averages of heat input. Using the Hourly Heat Input Vs. NOx emission rate curve (see slide 5), StackVision will estimate a corresponding NOx emission rate in lb./mmbtu. 20
11. For each of the four operating QA parameters, an average value was calculated for each of the average loads. Establish acceptable parametric ranges for these parameters at each tested load-heat input point. 12. The acceptable ranges should be based upon the turbine/engine manufacturer s recommendations. 13. Alternatively, the operator may use sound engineering judgement and operating experience with the unit to establish these acceptable ranges. 14. The rationale for choosing these parameters and establishing their ranges shall be included in the quality assurance plan for the unit. 21
15. For boilers which are using this protocol, the NOx emission rate heat input correlation should be review and possibly redetermined if the excess oxygen level at any heat input rate continuously exceeds by more than 2 percentage points O2 from the boiler excess oxygen level recorded at the same operating heat input rate from the last round of testing, if for one or more successive operating periods totally more than 16 unit operating hours. 16. For turbines and engines, the same holds true. Re-testing might be necessary after continuously exceeding the acceptable range of any of the QA parameters for one or more successive operating periods totaling more than 16 unit operating hours. 22
17. Setting up your correlation alarms is very important so you can track the performance of the QA parameters or boiler O2 levels. 18. In the Help area of SV, use the Configure NOx Correlation Alarms guidance to set up the NOXOOS (out-of-spec) and NOXRTEST (when 16 or more consecutive out-of-spec hours have occurred) alarms. 19. The alarms are configured in StackStudio and involve several configuration steps so use the guidance to walk you through the process. 20. Don t forget to setup ProcessNow to generate the hourly NOx emission rates from the hourly heat inputs and to generate the appropriate alarms when operating conditions are out of spec. 23
Use your in-house procedure to prepare for these periodic checks and tests. A consistent approach yields consistent and successful results. The data and results associated with these tests are included in the quality assurance file. These records can be generated at any time in SV and evaluated in ECMPS at any time. Don t wait until the end of the quarter to evaluate these results. Questions? Jkonings@envirosys.com or 512/250-7519. 24