1、Designation: D 6522 00 (Reapproved 2005)Standard Test Method forDetermination of Nitrogen Oxides, Carbon Monoxide, andOxygen Concentrations in Emissions from Natural Gas-Fired Reciprocating Engines, Combustion Turbines, Boilers,and Process Heaters Using Portable Analyzers1This standard is issued und
2、er the fixed designation D 6522; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since
3、 the last revision or reapproval.1. Scope1.1 This test method covers the determination of nitrogenoxides (NO and NO2), carbon monoxide (CO), and oxygen(O2) concentrations in controlled and uncontrolled emissionsfrom natural gas-fired reciprocating engines, combustion tur-bines, boilers, and process
4、heaters. Due to the inherent crosssensitivities of the electrochemical cells, this test methodshould not be applied to other pollutants or emission sourceswithout a complete investigation of possible analytical inter-ferences and a comparative evaluation with EPA test methods.1.1.1 The procedures an
5、d specifications of this method weredeveloped during laboratory and field tests funded by the GasResearch Institute (GRI).2Comparative emission tests wereconducted only on natural gas-fired combustion sources.1.2 The values stated in SI units are to be regarded as thestandard. The values given in pa
6、rentheses are for informationonly.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and to determine theapplicability of regulatory limit
7、ations prior to use.2. Referenced Documents2.1 ASTM Standards:3D 1356 Terminology Relating to Sampling and Analysis ofAtmospheres2.2 EPA Methods from 40 CFR Part 60, Appendix A4Method 3A - Determination of Oxygen and Carbon DioxideConcentrations in Emissions from Stationary Sources(Instrumental Anal
8、yzer Procedure)Method 7E - Determination of Nitrogen Oxides Emissionsfrom Stationary Sources (Instrumental Analyzer Proce-dure)Method 10 - Determination of Carbon Monoxide Emissionsfrom Stationary SourceMethod 20 - Determination of Nitrogen Oxides, SulfurDioxide, and Diluent Emissions from Stationar
9、y GasTurbines2.3 EPA Methods from 40 CFR Part 63, Appendix A4Method 301 - Field Validation of Pollutant MeasurementMethods from Various Waste Media2.4 EPA Methods from 40 CFR Part 75, Appendix H4Revised Traceability Protocol No. 1: Protocol G1 and G2Procedures3. Terminology3.1 For terminology releva
10、nt to this test method, see Termi-nology D 1356.3.2 Definitions of Terms Specific to This Standard:3.2.1 measurement system, ntotal equipment required forthe determination of gas concentration. The measurementsystem consists of the following major subsystems:3.2.1.1 data recorder, na strip chart rec
11、order, computer, ordigital recorder for recording measurement data.3.2.1.2 electrochemical cell, nthat portion of the systemthat senses the gas to be measured and generates an outputproportional to its concentration, or any cell that usesdiffusion-limited oxidation and reduction reactions to produce
12、an electrical potential between a sensing electrode and acounter electrode.3.2.1.3 external interference gas scrubber, ntube filledwith scrubbing agent used to remove interfering compoundsupstream of some electrochemical cells.1This test method is under the jurisdiction of ASTM Committee D22 on AirQ
13、uality and is the direct responsibility of Subcommittee D22.03 on AmbientAtmospheres and Source Emissions.Current edition approved Oct. 1, 2005. Published January 2006. Originallyapproved in 2000. Last previous edition approved in 2000 as D 6522 - 00.2Gas Research Institute Topical Report, “Developm
14、ent of an ElectrochemicalCell Emission Analyzer Test Method,” GRI-96/0008, July 1997.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary
15、page onthe ASTM website.4Available from Superintendent of Documents, U. G. Government PrintingOffice, Washington, DC 20402.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.2.1.4 sample interface, nthat portion of a system usedfor on
16、e or more of the following: sample acquisition, sampletransport, sample conditioning, or protection of the electro-chemical cells from particulate matter and condensed moisture.3.2.2 interference check, nmethod of quantifying analyti-cal interferences from components in the stack gas other thanthe a
17、nalyte.3.2.3 initial NO cell temperature, ntemperature of the NOcell that is recorded during the most recent pretest calibrationerror check.3.2.3.1 DiscussionSince the NO cell can experience sig-nificant zero drift with temperature changes in some situations,the temperature must be monitored if the
18、analyzer does notdisplay negative concentration results.3.2.4 linearity check, nmethod of demonstrating the abil-ity of a gas analyzer to respond consistently over a range of gasconcentrations.3.2.5 nominal range, nrange of concentrations overwhich each cell is operated (25 % to 125 % of span gas va
19、lue).3.2.5.1 DiscussionSeveral nominal ranges may be usedfor any given cell as long as the linearity and stability checkresults remain within specification.3.2.6 response time, namount of time required for themeasurement system to display 95 % of a step change in gasconcentration on the data recorde
20、r.3.2.7 span gas, nknown concentration of a gas in anappropriate diluent gas.3.2.8 span calibration error, ndifference between the gasconcentration exhibited by the gas analyzer and the knownconcentration of the span gas.3.2.9 stability check, nmethod of demonstrating that anelectrochemical cell ope
21、rated over a given nominal rangeprovides a stable response and is not significantly affected byprolonged exposure to the analyte.3.2.10 stability time, nelapsed time from the start of thegas injection to the start of the 30-min stability check period, asdetermined during the stability check.3.2.11 z
22、ero calibration error, ngas concentration exhib-ited by the gas analyzer in response to zero-level calibrationgas.4. Summary of Test Method4.1 Agas sample is continuously extracted from a stack andconveyed to a portable analyzer for determination of NO, NO2,CO, and O2gas concentrations using electro
23、chemical cells.Analyzer design specifications, performance specifications,and test procedures are provided to ensure reliable data.Additions to or modifications of vendor-supplied analyzers (forexample, heated sample line, flow meters, and so forth) may berequired to meet the design specifications o
24、f this test method.5. Significance and Use5.1 The results of this test method may be used to determinenitrogen oxides and carbon monoxide emissions from naturalgas combustion.5.2 This test method may also be used to monitor emissionsto optimize process operation for nitrogen oxides and carbonmonoxid
25、e control.6. Interferences6.1 NO and NO2can interfere with CO concentrationmeasurements, and NO2can interfere with NO concentrationmeasurements. The interference effects for the CO and NOemission measurements are quantified in 9.2 and shall notexceed 5 % of the measurement.7. Apparatus7.1 The minimu
26、m detectable limit depends on the nominalrange of the electrochemical cell, calibration drift, and signal-to-noise ratio of the measurement system. For a well designedsystem, the minimum detectable limit should be less than 2 %of the nominal range.7.2 Any measurement system that meets the performanc
27、eand design specifications in Sections 9 and 10.4.11 of this testmethod may be used. The sampling system shall maintain thegas sample at a temperature above the dew point up to themoisture removal system. The sample conditioning systemshall be designed so that there are no entrained water dropletsin
28、 the gas sample when it contacts the electrochemical cells. Aschematic of an acceptable measurement system is shown inFig. 1. The essential components of the measurement systemare described below:7.3 Sample Probe, glass, stainless steel, or other nonreactivematerial, of sufficient length to traverse
29、 the sample points, and,if necessary, heated to prevent condensation.7.4 Heated Sample Line, heated (sufficient to prevent con-densation), nonreactive tubing, to transport the sample gas tothe moisture removal system.7.5 Sample Transport Lines, nonreactive tubing to transportthe sample from the mois
30、ture removal system to the samplepump, sample flow rate control, and electrochemical cells.7.6 Calibration Assembly, a tee-fitting to attach to the probetip for introducing calibration gases at ambient pressure duringthe calibration error checks. The vented end of the tee shouldhave a flow indicator
31、 to ensure sufficient calibration gas flow.FIG. 1 Calibration System SchematicD 6522 00 (2005)2Any other method that introduces calibration gases at the probeat atmospheric pressure may be used.7.7 Moisture Removal System, a chilled condenser or similardevice (for example, permeation dryer), to remo
32、ve condensatecontinuously from the sample gas while maintaining minimalcontact between the condensate and the sample gas.7.8 Particulate FiltersFilters at the probe or the inlet oroutlet of the moisture removal system and inlet of the analyzermay be used to prevent accumulation of particulate materi
33、al inthe measurement system and extend the useful life of thecomponents. All filters shall be fabricated of materials that arenonreactive to the gas being sampled.7.9 Sample Pump, a leak-free pump, to pull the sample gasthrough the system at a flow rate sufficient to minimize theresponse time of the
34、 measurement system. The pump must beconstructed of any material that is nonreactive to the gas beingsampled.7.10 Sample Flow Rate Control, a sample flow rate controlvalve and rotameter, or equivalent, to maintain a constantsampling rate within 10 % during sampling and calibrationerror checks. The c
35、omponents shall be fabricated of materialsthat are nonreactive to the gas being sampled.7.11 Gas Analyzer, a device containing electrochemicalcells to determine the NO, NO2, CO, and O2concentrations inthe sample gas stream and, if necessary, to correct for interfer-ence effects. The analyzer shall m
36、eet the applicable perfor-mance specifications of Section 9. A means of controlling theanalyzer flow rate and a device for determining proper sampleflow rate (for example, precision rotameter, pressure gagedownstream of all flow controls, and so forth) shall be providedat the analyzer.NOTE 1Housing
37、the analyzer in a clean, thermally-stable, vibration-free environment will minimize drift in the analyzer calibration, but this isnot a requirement of the test method.7.12 Data Recorder, a strip chart recorder, computer, ordigital recorder, for recording measurement data. The datarecorder resolution
38、 (that is, readability) shall be at least 1 ppmfor CO, NO, and NO2; 0.1 % O2for O2; and 1 (C or F) fortemperature.Alternatively, a digital or analog meter having thesame resolution may be used to obtain the analyzer responsesand the readings may be recorded manually.7.13 External Interference Gas Sc
39、rubber, used by someanalyzers to remove interfering compounds upstream of a COelectrochemical cell.The scrubbing agent should be visible andshould have a means of determining when the agent isexhausted (that is, color indication).7.14 NO Cell Temperature Indicator, a thermocouple, ther-mistor, or ot
40、her device must be used to monitor the temperatureof the NO electrochemical cell. The temperature may bemonitored at the surface or within the cell.8. Reagents and Materials8.1 The analytical range for each gas component is deter-mined by the electrochemical cell design. A portion of theanalytical r
41、ange is selected by choosing a span gas concentra-tion near the flue gas concentrations.8.2 Calibration GasesThe calibration gases for the gasanalyzer shall be CO in nitrogen or CO in nitrogen and O2,NOin nitrogen, NO2in air or nitrogen, and O2in nitrogen.8.2.1 For the mid-level and span cylinder ga
42、ses, use cali-bration gases certified according to EPA Protocol G1 or G2procedures.8.2.2 Alternative certification techniques may be used, ifapproved in writing by the applicable regulatory agency.8.3 Span GasesUse these gases for calibration error,linearity, and interference checks of each nominal
43、range ofeach cell. Select concentrations as follows:8.3.1 CO and NO Span GasesChoose a span gas concen-tration such that the average stack gas reading for each test runis greater than 25 % of the span gas concentration. Alterna-tively, choose the span gas such that it is not greater than twicethe co
44、ncentration equivalent to the emission standard. Ifconcentration results exceed 125 % of the span gas at any timeduring the sampling run, then the test run for that channel isinvalid.8.3.2 NO2Span GasChoose a span gas concentrationsuch that the average stack gas reading for each test run isgreater t
45、han 25 % of the span gas concentration. Alternatively,choose the span gas concentration such that it is not greaterthan the ppm concentration value of the NO span gas. Thetester should be aware that NO2cells are generally designed tomeasure much lower concentrations than NO cells and the spangas sho
46、uld be chosen accordingly. If concentration resultsexceed 125 % of the span gas at any time during the samplingrun then the test run for that channel is invalid.8.3.3 O2Span GasChoose a span gas concentration suchthat the difference between the span gas concentration and theaverage stack gas reading
47、 for each run is less than 10 % O2.Where the stack oxygen is high, dry ambient air (20.9 % O2)may be used.8.4 Mid-Level GasesSelect mid-level gas concentrationsthat are 40 to 60 % of the span gas concentrations.8.5 Zero GasZero gas must have concentrations of lessthan 0.25 % of the span gas for each
48、 component. Ambient airmay be used in a well-ventilated area.9. Preparation of Apparatus9.1 Linearity Check:9.1.1 Conduct the linearity check once for each nominalrange that is to be used on each electrochemical cell (NO, NO2,CO, and O2) before each field test program.9.1.1.1 Repeat the linearity ch
49、eck immediately after 5 daysof analyzer operation, if a field test program lasts longer than5 days.9.1.1.2 Repeat the linearity check whenever a cell is re-placed.9.1.2 If the analyzer uses an external interference gasscrubber with a color indicator, verify that the scrubbing agentis not depleted, following the analyzer manufacturers recom-mended procedure.9.1.3 Calibrate the analyzer with zero and span gases.9.1.4 Inject the zero, mid-level, and span gases that areappropriate for each nominal range to be used on each cell.Gases need not be injected through
