ASTM D6563-2005e1 4375 Standard Test Method for Benzene Toluene Xylene (BTX) Concentrates Analysis by Gas Chromatography.pdf

1、Designation: D6563 051Standard Test Method forBenzene, Toluene, Xylene (BTX) Concentrates Analysis byGas Chromatography1This standard is issued under the fixed designation D6563; 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 () indicates an editorial change since the last revision or reapproval.1NOTEEditorial corrections were made in Table 1 and 13.3 in February 2010.1. Scope*1.1 This test method covers the determi

3、nation of the totalnonaromatic hydrocarbons, benzene, toluene, ethylbenzene,xylenes, and total C9+ aromatic hydrocarbons in BTX con-centrates by capillary column gas chromatography. This testmethod is applicable to materials with a final boiling pointbelow 215C.1.2 This test method may also be used

4、to determine therelative distribution of the individual C8aromatic hydrocarbonisomers in mixed xylenes.1.3 Individual components can be determined from 0.01 to90 %.1.4 In determining the conformance of the test results usingthis method to applicable specifications, results shall berounded off in acc

5、ordance with the rounding-off method ofPractice E29.1.5 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.6 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsib

6、ility 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. For a specificprecautionary statement, see Section 9.2. Referenced Documents2.1 ASTM Standards:2D3437 Practice for Sampling and Handling L

7、iquid CyclicProductsD6809 Guide for Quality Control and Quality AssuranceProcedures for Aromatic Hydrocarbons and Related Ma-terialsE29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE355 Practice for Gas Chromatography Terms and Rela-tionshipsE691 Prac

8、tice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE1510 Practice for Installing Fused Silica Open TubularCapillary Columns in Gas Chromatographs2.2 Other Documents:OSHA Regulations, 29 CFR paragraphs 1910.1000 and1910.120033. Terminology3.1 Definitions of Terms S

9、pecific to This Standard:3.1.1 extracted reformate, nAn aromatic concentrate ob-tained by solvent extraction of reformate.3.1.2 reformate, nThe product of a catalytic process thatincreases the concentration of aromatic hydrocarbons.3.1.3 pyrolysis gasoline, nDepentanized by-product re-covered from e

10、thylene manufacture.3.1.4 synthetic blend, nBlend of reagent hydrocarbonsthat simulate a process product.3.1.5 hydrogenated pyrolysis gasoline, nPyrolysis gaso-line that has been treated with hydrogen to reduce the olefinscontent.3.1.6 crude ethylbenzene, nProduct produced from thereaction of impure

11、 fluid cat cracking, (FCC) ethylene andbenzene.3.1.6.1 DiscussionIt typically contains greater than 40 %of ethylbenzene and benzene.3.1.7 light blending aromatics feedstock, nLight aromat-ics fraction (with high amounts of benzene and toluene)typically recovered from the isomerization of a p-xylene

12、orm-xylene depleted C8aromatics stream.3.1.8 mixed xylenes, na mixture of C8aromatic hydrocar-bon isomers including ethylbenzene, but excluding stryene.1This test method is under the jurisdiction of ASTM Committee D16 onAromatic Hydrocarbons and Related Chemicals and is the direct responsibility ofS

13、ubcommittee D16.01 on Benzene, Toluene, Xylenes, Cyclohexane and TheirDerivatives.Current edition approved July 1, 2005. Published August 2005. Originallyapproved in 2000. Last previous edition approved in 2000 as D6463 00. DOI:10.1520/D6563-05E01.2For referenced ASTM standards, visit the ASTM websi

14、te, 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 U.S. Government Printing Office Superintendent of Documents,732 N. Capitol St., NW, Mail Stop: SD

15、E, Washington, DC 20401, http:/www.access.gpo.gov.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4. Summary of Test Method4.1 The specimen to be analyzed is injected

16、into a gaschromatograph equipped with a flame ionization detector (FID)and a capillary column. The peak area of each component ismeasured and adjusted using effective carbon number (ECN)response factors. The concentration of each component iscalculated based on its relative percentages of total adju

17、stedpeak area and normalized to 100.00. To determine the relativedistribution of C8aromatic hydrocarbons, the peak areas ofthose components only are normalized to 100.00.4.2 Results can be reported as either volume or weightpercent. Volumetric results can be derived by dividing eachcomponents weight

18、 percent by its relative density and re-normalizing to 100 %.5. Significance and Use5.1 This test method was primarily developed to determinebenzene, toluene, and xylenes in chemical intermediate andsolvent streams such as reformate, BTX extracts, pyrolysisgasoline, hydrogenated pyrolysis gasoline,

19、crude benzene,crude ethylbenzene, commercial toluene, and light blendingaromatic feedstocks. This test method may not detect allcomponents and there may be unknown components thatwould be assigned inappropriate response factors and thus, theresults may not be absolute.5.2 The relative distribution o

20、f C8aromatics is useful fordetermining conformance to p-xylene feedstock specifications.6. Interferences6.1 Nonaromatic hydrocarbons may interfere with the de-termination of benzene and toluene when certain columns areused.6.2 Styrene may be present in some samples. It will elutewith C9+ aromatics.7

21、. Apparatus7.1 Gas ChromatographAny gas chromatograph having aflame ionization detector and a splitter injector suitable for usewith a fused silica capillary column may be used, provided thesystem has sufficient sensitivity, linearity, and range to obtain aminimum peak height response for a 0.01 % p

22、eak of five timesthe height of the signal background noise, while not exceedingthe full scale of either the detector or the electronic integrationfor the highest peak. The split injection system shall notdiscriminate over the boiling range of the samples analyzed.The system shall be capable of opera

23、ting at the conditionsgiven in Table 1.7.2 ColumnsThe choice of column is based upon resolu-tion requirements. Any column may be used that is capable ofresolving all the components of interest. The column andconditions described in Table 1 have been used successfullyand will be the referee in case o

24、f dispute.7.3 Recorder/Electronic IntegrationElectronic integrationwith tangent capabilities is recommended.8. Reagents8.1 Carrier GasHelium with a minimum purity of 99.99mol %.8.2 Detector GasHydrogen with a minimum purity of99.99 mol %.8.3 Flame Support GasAir, total, hydrocarbon less than 5ppm.9.

25、 Hazards9.1 Consult current OSHA regulations, suppliers MaterialSafety Data Sheets, and local regulations for all material usedin this test method.10. Sampling10.1 Sample material in accordance with Practice D3437.11. Preparation of Apparatus11.1 ChromatographFollow manufacturers instructionsfor mou

26、nting and conditioning the column in the chromato-graph. Adjust the instrument to the conditions as described inTable 1 to give the desired separation using the suggestedcolumn. Other columns may require different conditions toachieve the resolution requirements. Allow sufficient time forthe instrum

27、ent to reach equilibrium as indicated by a stablerecorder/electronic baseline. See Practices E355 and E1510 foradditional information on gas chromatography practices andterminology.12. Procedure12.1 Bring the sample to ambient room temperature.12.2 Inject an appropriate amount of sample into the chr

28、o-matograph that meets the criteria outlined in 7.1. See PracticesE355 and E1510 for additional information on gas chromatog-raphy practices and terminology.12.3 Sample chromatograms are illustrated in Figs. 1-4.12.4 Measure the area of all peaks. The non-aromaticsfraction includes all peaks up to e

29、thylbenzene (except for thepeaks assigned to benzene and toluene). Sum together all thenon-aromatic peaks as a total area. The C9+ aromatics fractionincludes all peaks eluting after m-xylene except for 0-xylene.Sum together all the C9+ aromatic peaks as a total area.13. Calculation13.1 Calculate the

30、 weight percent concentration of eachcomponent as follows:TABLE 1 Instrument ParametersColumn 50 or 60 m by 0.25 mm ID bondedpolyethylene glycol-fused silica capillary,internally coated to a 0.25-m thicknessCarrier gas heliumFlow, linear velocity at 70C, cm/s 20Split ratio 200:1Detector gasHydrogen

31、flow rate, mL/min 30Air flow rate, mL/min 300Make-up flow rate, mL/min 30Sample size, L 0.5TemperaturesInjector, C 250Detector, C 300ColumnInitial, C 70Hold, min 10Rate, C/min 5Final, C 200Hold, min 24D6563 0512FIG. 1 Synthetic BlendD6563 0513FIG. 2 Pyrolysis GasolineD6563 0514FIG. 3 Extracted Refor

32、mateD6563 0515FIG. 4 Mixed XylenesD6563 0516Ci5100 3 Ai3 ECNi(i 5 1nAi3 ECNi!(1)where:Ci= concentration of component inweight percent,Ai= area of component, i peak,ECNi= effective carbon response factorfor component, and(i 5 1nAi3 ECNi! = the summation of all response cor-rected areas in the chromat

33、ogram.13.2 Calculate the volume percent concentration of eachcomponent as follows:V 5100 C/D(i 5 1nC/D!(2)where:V = calculated vol % concentration of component,C = calculated wt % concentration of component from12.1,D = relative density of component, andi=1n= sum of the quotients C/D.13.3 Use the fo

34、llowing effective carbon number (ECN)response factors for the calculations:ComponentECN ResponseFactorA,BRelative DensityCat15.56CNon Aromatics 1.0000 0.7200 (average)Benzene 0.9100 0.8829Toluene 0.9200 0.8743Ethylbenzene 0.9275 0.8744p-Xylene 0.9275 0.8666m-Xylene 0.9275 0.8694o-Xylene 0.9275 0.884

35、9_ C9+ aromatics 0.9333 0.8752 (average)AScanlon, J., T., and Willis, D., E., “Calculation of Flame Ionization DectorRelative Response Factors Using the Effective Carbon Number Concept” Journalof Chromatographic Science, Vol 35, August, 1985, pp. 333-339.BResponse Factors are relative to n-heptane.C

36、DS#4APhysical Constants of Hydrocarbons C1through C10, ASTM, 1971.13.4 Calculate the weight percent relative distribution ofeach C8aromatic hydrocarbon as follows:F15100 3 B1(i 5 1nB1(3)where:F1= concentration of component in weight percent,B1= peak area of component i, and= peak area o fall C8aroma

37、tic isomers.14. Report14.1 Report the following information:14.1.1 All component concentrations to the nearest 0.01 wt(or vol) %.14.1.2 For concentrations less than 0.01 wt (or vol) %,report as 0.01 wt (or vol) %.15. Precision and Bias415.1 PrecisionThe following criteria should be used tojudge the

38、acceptability of results obtained by this test method(95 % confidence level). The precision criteria were derivedfrom an interlaboratory study using data submitted by fourteenlaboratories (ten laboratories for mixed xylenes. Each inter-laboratory study participant was provided two gravimetricallypre

39、pared BTX known samples and three unknown samples ofvarying concentrations. Each sample was run twice on twodays by two different operators. Results of the interlaboratorystudy were calculated and analyzed using Practice E691.15.2 Intermediate Precision, (formerly Repeatability)Results in the same l

40、aboratory should not be consideredsuspect unless they differ by more than 6 the amount shown inTable 2, Table 3, Table 4, Table 5, Table 6,orTable 7.Onthebasis of test error alone, the difference between two resultsobtained in the same laboratory on the same material will beexpected to exceed this v

41、alue only 5 % of the time.15.3 ReproducibilityResults submitted by each of twolaboratories should not be considered suspect unless they differby more than 6 the amount shown in Table 2, Table 3, Table4, Table 5,orTable 6. On the basis of test error alone, thedifference between two results obtained i

42、n different laborato-ries on the same material will be expected to exceed this valueonly 5 % of the time.15.4 BiasFor mixed xylenes, the interlaboratory test uti-lized a sample prepared gravimetrically from individual fromindividual C8isomers obtained at the highest purity available.However, this sa

43、mple has not been approved as an acceptablereference material and consequently bias has not been deter-mined.15.4.1 As an aid for the users in determining the possibilityof bias, calculated C8distributed for the round robin sample islisted in Table 7 as the “Expected Concentration.” The averagevalue

44、 for each C8isomer as calculated from the reportedconcentrations is listed as “Average Concentration Reported.”16. Quality Guidelines16.1 Refer to Guide D6809 for suggested QA/QC activitiesthat can be used as a part of this method. It is recommended4Supporting data have been filed at ASTM Internatio

45、nal Headquarters and maybe obtained by requesting Research Report RR:D16-1025. Supporting data formixed xylenes are available separately: Request Research Report RR:D16-1015.TABLE 2 Interlaboratory Precision and Reproducibility forSynthetic Blend SampleNOTE 1This data was calculated after removal of

46、 outliers usingPractice E691.ComponentConcentrationWeight %IntermediatePrecisionReproducibilityNonaromatics 22.447 0.296 1.746Benzene 42.891 0.781 1.887Toluene 19.961 0.212 0.715Ethylbenzene 3.061 0.055 0.191Total xylenes 7.921 0.195 0.512C9+ aromatics 4.192 0.169 1.009D6563 0517that the operator of

47、 this method select and perform relevantQA/QC activities like the ones in Guide D6809 to help insurethe quality of data generated by this method.17. Keywords17.1 BTX concentrates; BTX extracts; capillary gas chro-matography; commercial toluene; crude benzene; crude ethyl-benzene; hydrogenated pyroly

48、sis gas; light blending aromaticfeedstock; mixed xylenes; pyrolysis gasTABLE 3 Interlaboratory Precision and Reproducibility forPyrolysis Gasoline SampleNOTE 1This data was calculated after removal of outliers usingPractice E691.ComponentConcentrationWeight %IntermediatePrecisionReproducibilityNonar

49、omatics 17.918 0.237 1.394Benzene 36.580 0.666 1.610Toluene 17.117 0.181 0.613Ethylbenzene 1.519 0.027 0.095Total xylenes 6.271 0.154 0.406C9+ aromatics 20.419 0.823 4.917TABLE 4 Interlaboratory Precision and Reproducibility forExtracted Reformate SampleNOTE 1This data was calculated after removal of outliers usingPractice E691.ComponentConcentrationWeight %IntermediatePrecisionReproducibilityNonaromatics 0.264 0.003 0.021Benzene 21.015 0.382 0.925Toluene 34.516 0.366 1.236Ethylbenzene 5.473 0.098 0.342Total xylenes 2