1、Designation: D 7459 08Standard Practice forCollection of Integrated Samples for the Speciation ofBiomass (Biogenic) and Fossil-Derived Carbon DioxideEmitted from Stationary Emissions Sources1This standard is issued under the fixed designation D 7459; the number immediately following the designation
2、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 () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice defines specific procedu
3、res for the collec-tion of gas samples from stationary emission sources forsubsequent laboratory determination of the ratio of biomass(biogenic) carbon to total carbon (fossil derived carbon plusbiomass or biogenic carbon) in accordance with D 6866.1.2 This practice applies to stationary sources tha
4、t burnmunicipal solid waste or a combination of fossil fuel (forexample, coal, oil, natural gas) and biomass fuel (for example,wood, wood waste, paper, agricultural waste, biogas) in boil-ers, combustion turbines, incinerators, kilns, internal combus-tion engines and other combustion devices.1.3 Thi
5、s practice applies to the collection of integratedsamples over periods from 1 hour to 24 hours, or longer.1.4 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.5 This standard does not purport to address all of thesafety concern
6、s, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 1356 Terminology Relating to Sampling an
7、d Analysis ofAtmospheresD 4840 Guide for Sample Chain-of-Custody ProceduresD 6866 Test Methods for Determining the Biobased Con-tent of Natural Range Materials Using Radiocarbon andIsotope Ratio Mass Spectrometry Analysis2.2 Federal Standards:340 CFR 60 Appendix B, Performance Specification40 CFR 60
8、 Appendix A, Reference MethodUncertainties In Non-Proportional Sampling, Part 75Policy And Communication Efforts, EPA Contract No.EP-W-07-064, Work Assignment No. 0-8, Task No. 6(February 15, 2008 Draft)3. Terminology3.1 DefinitionsFor additional definitions of terms used inthis practice, refer to T
9、erminology D 1356 and Test MethodsD 6866.3.2 Definitions of Terms Specific to This Standard:3.2.1 biomass (biogenic) CO2, nCO2recently removedfrom the atmosphere by plants, then returned to the atmosphereby combustion or biogenic decay.3.2.1.1 DiscussionBiomass CO2emitted from combus-tion devices is
10、 often referred to as “carbon-neutral CO2.”3.2.1.2 DiscussionBiomass carbon contains the isotoperadiocarbon (carbon-14) in measurable quantities. Radiocarbonis a radioactive isotope of the element carbon, carbon-14,having 8 neutrons, 6 protons, and 6 electrons making up 1 310-12natural abundance of
11、carbon on earth. It decays exponen-tially with a half-life of about 5700 years and as such is notmeasurable in fossil materials derived from petroleum, coal,natural gas or any other source more than about 50,000 yearsold.3.2.2 constant rate sampling, nsampling conducted at afixed sampling rate.3.2.3
12、 Fossil CO2, nCO2introduced into the atmospherethrough the combustion or thermal dissociation of fossilmaterials.3.2.3.1 DiscussionFossil-derived CO2is void of radiocar-bon and consists entirely of the “stable carbon” isotopescarbon-13 (having 7 neutrons, 6 protons, and 6 electrons)making up 1.2 % n
13、atural abundance carbon on earth and1This practice is under the jurisdiction of ASTM Committee D22 on Air Qualityand is the direct responsibility of Subcommittee D22.03 on Ambient Atmospheresand Source Emissions.Current edition approved Aug. 1, 2008. Published August 2008.2For referenced ASTM standa
14、rds, 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 page onthe ASTM website.3Available from Standardization Documents Order Desk, DODSSP, Bldg. 4,Section D, 700 Rob
15、bins Ave., Philadelphia, PA 19111-5098, http:/www.dodssp.daps.mil.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.carbon-12 (having 6 neutrons, 6 protons, and 6 electrons) andmaking up 98.8 % natural abundance carbon on earth.3.2.4 p
16、roportional sampling, nsampling conducted suchthat the ratio of the sampling rate to stack gas velocity orvolumetric flow rate is constant.3.2.5 speciation, nidentification of the biomass and fossil-derived CO2components within bulk air effluents.3.2.6 sub-sampling, nthe process of taking a represen
17、ta-tive smaller amount of sample volume from a large bulksample volume.4. Summary of Practice4.1 Representative gas samples are collected at a constantrate from stationary emission sources into portable containersfor shipment to off-site analytical facilities performing D 6866analysis.NOTE 1The comp
18、lexity of the analytical method requires analysis tobe performed off-site.4.2 If the variability of stack gas velocity or CO2concen-tration, or both, is beyond specified limits, proportional ratesampling may need to be used. See Section 8.NOTE 2The majority of combustion sources are such that theiro
19、perational conditions do not vary significantly and, hence, constant ratesampling would provide representative samples. However, there are somesources, for example, peaking units, whose effluent flow rate (velocity)and CO2concentrations vary considerably. In such cases, it is necessary tosample prop
20、ortionally. Guidelines are given on when proportional sam-pling is necessary.5. Significance and Use5.1 Greenhouse gases are reported to be a major contributorto global warming. Since “biomass CO2” emitted from com-bustion devices represents a net-zero carbon contribution to theatmosphere (that is,
21、plants remove CO2from the atmosphereand subsequent combustion returns it), it does not contributeadditional CO2to the atmosphere. The measurement of biom-ass (biogenic) CO2allows regulators and stationary sourceowners/operators to determine the ratio of fossil-derived CO2and biomass CO2in developing
22、 control strategies and to meetfederal, state, local and regional greenhouse gas reportingrequirements.5.2 The distinction of the two types of CO2has financial,control and regulatory implications.6. Apparatus6.1 ProbeTubing of sufficient length, equipped with anin-stack or out-stack filter to remove
23、 particulate matter. Theprobe may be made of any material that is inert to CO2andresistant to temperature at sampling conditions, for example,stainless steel, borosilicate glass, quartz, or polytetrafluoroet-hylene. The filter may be a plug of glass wool. Samples mayalso be taken at the exhaust of a
24、ny extractive continuousemission monitoring system (CEMS) used for monitoringpollutant or diluent concentrations, including both full extrac-tive and dilution sampling systems.NOTE 3Samples may be collected using EPAMethod 3 in conjunctionwith applicable US EPA reference test methods requiring Metho
25、d 5sampling apparatus.6.2 CondenserAir-cooled, water-cooled, or other con-denser to remove excess moisture that would interfere with theoperation of the pump and flow meter. The condenser must notremove any CO2. The condenser may be omitted if themoisture concentrations are too low for condensation,
26、 forexample, after dilution CEMS.NOTE 4CO2is slightly soluble in water; its effect is estimated to beless than about 0.2 %. Acid gases (for example, SO2, HCl) reduce thesolubility of CO2to a negligible level. In addition, since the methodinvolves ratios of biomass to fossil derived CO2, any solubili
27、ty (if any) ofCO2in water does not affect the results.6.3 ValveNeedle valve, or equivalent, to adjust samplingflow rate. The valve may be omitted if a pump that samples ata constant rate is used.6.4 PumpLeak-free diaphragm-type pump, or equivalent,to transport sample gas to the flexible bag. It may
28、be necessaryto install a small surge tank between the pump and rate meterto eliminate the pulsation effect of the diaphragm pump on therotameter.6.5 Rate MeterRotameter, or equivalent rate meter, ca-pable of measuring sample flow rate to within 62.0 % of theselected flow rate.6.6 Sample ContainerAir
29、 tight vessel that is compatiblewith the system design, which includes flexible bags, evacu-ated canisters such as Summa canisters, vacutainer, Tedlar bag,or syringes.6.6.1 The capacity of the sample container must be largeenough to contain at least 2 cm3of CO2(sample containercapacity (L) 3 %CO23 1
30、0$2cm3) at the end of the samplingperiod.6.6.2 If sub-samples are used for shipment to the laboratory,then determine the size of the sub-sample container such that itwill contain at least 2 cm3of pure CO2.6.7 Flow Rate IndicatorIndicator that is proportional tostack gas velocity or volumetric flow r
31、ate. The following areacceptable indicators: Type S pitot tube (velocity pressure, asmeasured by manometer, transducer, etc.); ultrasonic, scintil-lation, thermal or other continuous flow devices; steam rates,boiler feed water, power generation (MW), process loads, fuelrates, or other proportional e
32、ffluent flow equivalents.NOTE 5In most combustion sources, moisture can be assumed to beconstant; however, if moisture varies by more than 610 % moisture(absolute) from the average, record hourly moisture content values todetermine the effect on the constant sample rate. Constant sampling rate isbas
33、ed on the moisture content at stack conditions, while the actualsampling rate is determined on a dry basis.NOTE 6If a pitot tube is used, the determination of gas density is notneeded. The square root of the velocity pressure should be used in thecalculations.6.8 Quality Assurance/Quality Control Eq
34、uipmentAs in-dicated in Section 8.7. Procedure7.1 Set up the sampling train as shown in Fig. 1 or Fig. 2.7.2 When using the Fig. 1 configuration, locate the tip of thesampling probe within or centrally located over the centroidalarea of the duct or stack cross-section or at least 1 meter infrom the
35、duct or stack wall. When using the Fig. 2 configura-tion, it is preferable to sample after the CO2monitors intake.D7459082Ensure that the attachment of the CO2sampling equipmentdoes not interfere with the normal operation of the existingequipment by adding significant restriction or back pressure, o
36、raffecting the analyzer flow rate(s).NOTE 7When using EPA Method 3 in conjunction with EPA Method5 sampling apparatus, an integrated multipoint sample taken at eachsampling point is acceptable.7.3 If the flow indicator is a pitot tube, insert the sensingportion of the pitot in an interference-free l
37、ocation next to theprobe, for example, attaching the pitot to the probe with thesensor tip extending at least 5.1 cm beyond the tip of the probe.7.4 Record the sample location, time and date of thecommencement of collection and the operators name on thecontainer. During the sampling period, record t
38、he date andtime, the sample flow rate (including temperature and pres-sure), and readings from the flow rate indicator at least at thefollowing frequencies.7.4.1 $6 hours sampling time every hour7.4.2 3, 4, or 5 hours sampling time every 30 minutes7.4.3 2 hours sampling time every 20 minutes7.4.4 1
39、hour sampling time every 10 minutes7.5 Sample at a constant rate within 610 % of the initialreading. Record the % deviation from initial reading at eachrecording of sampling rate.7.6 Using the readings from the flow rate indicator (forexample, pressure differential, steam rate, fuel rate), calculate
40、the mean () and standard deviation (s). If 2 s/ x 100 (or twotimes the relative standard deviation or 2RSD) #55 %, thecondition for constant rate sampling has been met; if not, thensampling must be conducted proportionally in accordance with7.6.1 through 7.6.3.NOTE 8The #55 % (2RSD) specification wa
41、s developed based onelectric utility coal-fired units where the %CO2variation was #40 %(2RSD). Under steady state conditions, the velocity or %CO2variationsfrom municipal solid waste or agricultural waste combustors are notexpected to reach these levels, that is, 55 % for velocity or 40 % for%CO2.7.
42、6.1 Record the initial sampling flow and pitot tube pres-sure differential (or other stack flow monitoring devices or flowrate indicator), and calculate the ratio.7.6.2 Maintain this ratio throughout the sampling period towithin 610 % of the initial ratio.7.6.3 Calculate the % deviation from the ini
43、tial ratio asfollows:%Deviation each sampling period! 5SSampling Period RatioInitial Ratio1D3 100 (1)7.7 At the end of the sampling period, securely close thesample container and remove it from the apparatus.7.8 Prepare the sample for shipment to the analyticallaboratory by one of the following proc
44、edures:NOTE 9The final sample must contain at least 2 cm3CO2. In somecases, several sub-sample containers may be required for analysis. SeveralFIG. 1 Sampling Train Configuration Using a ProbeFIG. 2 Sampling Train Configuration After CEMSD7459083sub-samples may be proportionately combined into a sin
45、gle samplecontainer for analysis. The source may wish to retain several back-upsamples.7.8.1 Ship the sample container as is.7.8.2 Transfer a sub-sample into a smaller container orproportionately combine multiple sub-samples.7.9 Document sample custody to ensure sample and dataintegrity in accordanc
46、e with Guide D 4840.8. Quality Assurance and Quality Control8.1 Constant Sampling Rate CheckCalculate the percentdeviation from the initial sampling rate. No value shall exceed610 %. If this limit is exceeded, invalidate the sample.8.2 Stack Flow Rate VariationCalculate the average stackflow rate in
47、dicator and 2RSD (twice the standard deviationrelative to the average). The 2RSD must be less than 30 %.8.3 Leak ChecksConduct a leak check of the container asfollows:NOTE 10Since the analysis is based on a ratio of14C/12C, leakingcontainers would not invalidate the sample. However, large leaks migh
48、tpose a problem by diluting the samples to the point where there isinsufficient CO2to analyze; therefore containers indicating leaks shouldnot be used.8.3.1 Perform the leak check before (mandatory) the test.Fill the container with gas, connect a water manometer, andpressurize the container to 5 to
49、10 cm H20. Allow to stand for10 minutes. Any displacement in the water manometer indi-cates a leak.8.3.2 An alternative leak check method for flexible bags isto pressurize the bag to 5 to 10 cm H20 and allow to standovernight. A deflated bag indicates a leak.8.3.3 Do not use any container that indicates a leak.8.4 Rate Meter CheckThe rate meter needs no calibration.Ensure that it is clean and free flowing.9. Report9.1 Include the following information in the Field SamplingReport:9.1.1 Source Identification and Description9.1.2 Tester In
