1、Designation: D 6060 96 (Reapproved 2001)Standard Practice forSampling of Process Vents with a Portable GasChromatograph1This standard is issued under the fixed designation D 6060; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the
2、 year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice describes a method for direct sampling andanalysis of process vents for volatile organic compo
3、und (VOC)vapors and permanent gases using a portable gas chromato-graph (GC).1.2 This practice is applicable to analysis of permanentgases such as oxygen (O2), carbon dioxide (CO2) and nitrogen(N2), as well as vapors from organic compounds with boilingpoints up to 125C.1.3 The detection limits obtai
4、ned will depend on the por-table gas chromatograph and detector used. Detectors availableinclude thermal conductivity, photoionization, argon ioniza-tion, and electron capture. For instruments equipped withthermal conductivity detectors, typical detection limits are oneto two parts per million by vo
5、lume (ppm(v) with an applicableconcentration range to high percent by volume levels. Forinstruments with photoionization detectors detection limit ofone to ten parts per billion by volume (ppb(v) are obtainablewith a concentration range from 1000 to 2000 ppm(v). Theargon ionization detector has an a
6、chievable detection limit ofone (ppb(v), while the electron capture detector has anachievable detection limit of one part per trillion by volume(ppt(v) for chlorinated compounds.1.4 The applicability of this practice should be evaluated foreach VOC by determining stability, reproducibility, and line
7、ar-ity.1.5 The appropriate concentration range must also be deter-mined for each VOC, as the range will depend on the vaporpressure of the particular VOC.1.6 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of t
8、his standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. Refer to Section 8on Hazards for additional safety precautions.2. Referenced Documents2.1 ASTM Standards:2D 1356 Terminology Relating to Sampling and Analysis o
9、fAtmospheresD 3464 Test Method forAverage Velocity in a Duct Using aThermal AnemometerD 3154 Test Method for Average Velocity in a Duct (PitotTube Method)E 355 Practice for Gas Chromatography Terms and Rela-tionships2.2 Other Document:NFPA 496 Standard for Purged and Pressurized Enclosuresfor Electr
10、ical Equipment33. Terminology3.1 DefinitionsFor the definition of terms used in thispractice, refer to Terminology D 1356 and Practice E 355.3.2 Definitions of Terms Specific to This Standard:3.2.1 portablerefers to gas chromatograph with internalbattery, internal sample pump, and internal/rechargea
11、ble carriergas supply cylinder.4. Summary of Practice4.1 One end of a sampling line (typically 6 mm (14 in.)outside diameter TFE-fluorocarbon tubing) is connected to atee in a process vent and the other end to a condensation trap(see 6.1), which is connected to a gas sampling bulb. The outletof the
12、gas sampling bulb is connected to a sampling pump setat a flow rate of 0.5 to 2 L/min. The sample line from theportable gas chromatograph is inserted through the septum portof the gas sampling bulb.At user selected intervals, the internalpump of the portable gas chromatograph is activated andprocess
13、 vapors drawn through the injection valve of the gaschromatograph and analyzed.1This test method is under the jurisdiction of ASTM Committee D22 onSampling and Analysis of Atmospheres and is the direct responsibility of Subcom-mittee D22.03 on Ambient Atmospheres and Source Emissions.Current edition
14、 approved December, 10, 1996. Published February 1997.2For 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 page onthe ASTM website.3Availa
15、ble from National Fire Protection Assn., 1 Batterymarch Park, P.O. Box9101, Quincy, MA 02269-9101.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5. Significance and Use5.1 This practice has been widely used to obtain massbalance dat
16、a for process scrubbers, to determine the efficiencyof VOC emission control equipment, and to obtain data tosupport air permit applications.5.2 This practice will have applications to the MACT Ruleand may have applications to Compliance Assurance Monitor-ing verification required by the 1990 Clean A
17、ir Act Title IIIAmendments.5.3 This practice, when used with Test Methods D 3464 orD 3154 or on-line process flow meter data, can be used tocalculate detailed emission rate profiles for VOCs from processvents.5.4 This practice provides nearly real time results that candetect process changes or upset
18、s that may be missed usingconventional sorbent tube or integrated gas sampling bagsampling.6. Interferences6.1 Water or liquid in the process line will plug the sampleline of the gas chromatograph, since the injection valve of mostportable GCs is not heated. The condensation trap is designedto prote
19、ct the portable gas chromatograph if liquids are presentor occur during process upset.6.2 Interferences sometimes result from analytes havingsimilar retention times during gas chromatography.6.3 General approaches which can be followed to resolvesuch interferences are given below:6.3.1 Change the ty
20、pe of column, length of column, oroperating conditions.6.3.2 Analyze using a nonpolar methyl silicone columnwhich separates according to boiling point of the compoundsand a polar column whose separations are influenced by thepolarity of the compounds.46.3.3 Use a mass spectrometer to verify the iden
21、tity ofpeaks.7. Apparatus7.1 A schematic drawing of a typical sampling setup isshown in Fig. 1. The laptop computer may be physicallylocated near the gas chromatograph as shown in Fig. 1,orlocated remotely. In addition, some portable gas chromato-graphs have an integral computer. Use a short piece o
22、f 1.5 mm(116 in.) outside diameter by 1 mm (0.04 in.) inside diameterstainless steel tubing as the sampling probe line from the gassampling bulb to the GC inlet.7.2 Portable Gas Chromatograph (GC), with a thermalconductivity, photoionization, argon ionization, electron cap-ture or appropriate detect
23、or, internal/rechargeable carrier gassupply, and internal sampling pump.7.2.1 Portable gas chromatographs are typically equippedwith particulate filters which should be replaced periodically.7.3 Data Logger, device used for automated storage ofoutput from a flow measurement device.7.4 Gas Sampling B
24、ulb, 125 mL capacity with septum port.7.5 Personal Sampling Pump.4The columns in most portable gas chromatographs are easily interchanged. Onemanufacturer has an instrument that simultaneously injects onto two user selectedcolumn modules.FIG. 1 Schematic of Process Sampling EquipmentD 6060 96 (2001)
25、27.6 Gas-Tight Syringe, 1, 10, 100, 500 mL capacity or otherconvenient sizes for preparing standards.7.7 Microlitre Syringes, 10, 25, 50, 100 L or other conve-nient sizes for preparing standards.7.8 Gas Sampling Bags, for preparation of gas standards.Bags constructed of various polymer films, such a
26、s polyvi-nylidene fluoride, fluorinated ethylenepropylene,(tetrafluoroethylene)-fluorocarbon, polyvinylidene chloride,polyethylene and mixed polymer multilayers, with a variety offittings and capacities (typically 1 to 200 L) are available.7.9 Thermal Anemometer, Vane Anemometer, Mass Flowme-ter or
27、Pitot Tube, for measurement of vent velocity.7.10 Condensation Trap, Filtering Flask, 250 or 500 mLpolypropylene fitted with a stopper.7.11 TFE-Fluorocarbon Tubing, 6 mm (14 in.) outsidediameter by 5 mm (316 in.) inside diameter.7.12 Data System, an integral or external computer used forcontrol of o
28、peration of a portable gas chromatograph, datareduction, and storage of results.8. Hazards8.1 See NFPA 496 for use of electrical equipment in areasclassified as hazardous by Article 500 of NFPA 70, NationalElectrical Code. A purged and pressurized enclosure is re-quired.9. Calibration9.1 Suitable kn
29、owns may be prepared by the filling of a gassampling bag with a known volume of air. Inject a knownvolume of gas or liquid into the bag and knead the bag to mix.Permeation tubes or rigid chambers may also be used forpreparation of gas standards. Reference standards in com-pressed gas cylinders certi
30、fied as to concentration by themanufacturer are also available. Refer to Methods of AirSampling and Analysis5for applicable guidelines for all ofthese gas standard preparation techniques.9.2 Although standards of some compounds prepared in gasbags are very stable, others show sample loss during stor
31、agedue to permeation or surface adsorption.As a general guidelineprepare standards fresh daily.9.3 Prepare at least two reference standards containingvarying concentrations of each component. Bracket the ex-pected concentrations of each component in the testing of theprocess vent, if known.9.3.1 Con
32、nect the gas sampling bag to the inlet or thecalibration port of the GC and initiate the analysis. Perform atleast triplicate injections of each standard.9.3.2 The quantitative response of a GC detector may bedetermined by the measurement of the peak height or peak areausing the Data System or elect
33、ronic integrator.69.3.3 Following the standard analyze a gas sampling bagcontaining air only (blank). If carryover is 1 % increase thesampling period (internal GC pump time). Typical samplingperiods are 20 to 45 s, however, this parameter must beoptimized for each VOC analyzed.10. Procedure10.1 Prep
34、aration of the Gas Chromatograph:10.1.1 Fill the internal carrier gas reservoir as described bythe manufacturer.10.1.2 Select a carrier gas flow or column pressure andcolumn temperature compatible with the column selected forthe separation.10.1.3 Calibrate the chromatographic column to determinethe
35、relative retention times and response of the variouscompounds of interest.10.2 Preparation of the Sampling Train:10.2.1 Assemble the sampling train as shown in Fig. 1.Stainless steel or glass may be substituted for the TFE-fluorocarbon transfer line.710.2.2 For process vents containing high concentr
36、ations ofhigher boiling (125C) low vapor pressure (115 %, repeat the analysis of the vent after identifying sourceof the problem. Typical causes of poor recovery include leak insample train, partially or completely plugged instrument filter,improper internal pump or injection valve operation, anddet
37、ector malfunction.10.3.5 Data reduction, either by peak height or peak areameasurement, may now be performed. Some portable GCsautomatically develop files that can be directly loaded into anEXCEL or Lotus spreadsheet format. Most data loggers forrecording of flow also develop files that can be easil
38、y loadedinto spreadsheets, which can be combined into one spreadsheetto develop a detailed emission rate profile for each organiccompound. An example of a typical spreadsheet is given inAppendix X1.10.3.6 By direct sampling of process vents with a portablegas chromatograph, process trends and condit
39、ions can bemonitored and more easily and quickly optimized. A graphicaldisplay illustrating how simultaneous monitoring of the inletand outlet of a water scrubber using two portable gas chro-matographs aided optimization of flow rate required to removean organic compound from a vent stream is shown
40、inAppendixX2. This chart was created in EXCEL from the data shown inAppendix X1.11. Calculations11.1 Calculation of the Concentration of Organic ChemicalVapor Standards in Gas Sampling Bags:11.1.1 Calculate the concentration C in parts per million byvolume (ppm(v) as follows:c 5L 3 D 3 1000 3 24.45M
41、W 3 V(1)where:L = volume of liquid added to bag, L,D = density of liquid, kg/m3,24.45 = molar volume of ideal gas, L/mole, at 25C and101.3 kPa pressure (760 mm Hg),MW = molecular weight of compound, g/mol, andV = total volume = volume air in bag plus volume ofvaporized liquid added, L, and1000 = 100
42、0 mL/L.11.2 Calculate the vent flow rate at standard conditions.11.2.1 For instruments that correct to standard conditionscalculate as follows:F 5 V 3 A 3 1000 (2)where:F = flow, L/min at 25C and 101.3 kPa pressure (760 mmHg),V = air velocity, m/min, andA = vent cross sectional area, m2.11.2.2 For i
43、nstruments that do not automatically correct tostandard conditions:F 5V 3 A 3 P 3 298 3 1000101.3 3 T 1 273!(3)where:P = pressure of vent in kPa, andT = temperature of vent, C.11.3 Calculate the emission rate of organic compound.11.3.1 Calculate ER, the emission rate in kg/h as follows:ER 5C 3 10263
44、 MW 3 F 3 6024.45 3 1000(4)where:C = concentration of compound, ppm(v) (L/L),106= conversion factor for L to L, and1000 = conversion factor for g to kg.12. Keywords12.1 emissions; emission monitoring; gas chromatography;sampling and analysisAPPENDIXES(Nonmandatory Information)X1. EXCEL SPREADSHEET O
45、F PORTABLE GC RESULTS FOR VOC IN PROCESS VENTX1.1 The data contained in Columns 1 to 3 in Table X1.1were obtained by loading .dif file created by portable GC intoan EXCEL spreadsheet. Column 1 is the date and time thesample was analyzed, while Columns 2 and 3 are the concen-trations in ppm(v) of Com
46、pound A (CPD-A) found at the inletand outlet of the scrubber vent. The data in Column 4 werecreated by loading data stored by data logger for process ventflow into the EXCEL spreadsheet. The data logger stores avoltage reading which has to be converted to a flow reading.Data contained in the other c
47、olumns are calculated from data inColumns 2 to 4. Column 5 is Vent Flow (ft/min) = 10 000 3 Voltage Reading of Data Logger. Flow is atstandard conditions of 25C and 101.3 kPa pressure. Column 6is vent flow in meters/min (m/min) = .30480 3 values in Col-umn 5. Column 7 is flow in standard L/min obtai
48、ned using EqEq 2. Columns 8 and 9 obtained using Eq Eq 4 convert theconcentrations in ppm(v) at the inlet and outlet of the scrubberto kg/h entering and exiting the water scrubber. Column 10 iswater flow in litres/min. Column 11 is scrubberefficiency=1(Column 9/Column 8) 3 100.D 6060 96 (2001)4FIG.
49、X1.1 EXCEL Spreadsheet of Portable GC Results for VOC in Process VentsD 6060 96 (2001)5X2. GRAPH OF KG/H OF VOC INTO AND OUT OF WATER SCRUBBER VERSUS FLOW RATE OF WATER THROUGHSCRUBBERX2.1 The graph (Fig. X1.2) is a plot of Columns 8 and 9(kg/h of Compound A entering and exiting the water scrubber)of Table X1.1 versus the flow rate of water through thescrubber (Column 10). It illustrates how direct monitoring of aprocess vent with a portable GC can aid optimization ofprocess variables such as scrubber flow rate.ASTM International takes no position respecting
