ASTM_D_6159_-_97_2012.pdf

Designation:D615997(Reapproved 2012)Standard Test Method forDetermination of Hydrocarbon Impurities in Ethylene by GasChromatography1This standard is issued under the fixed designation D6159;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()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers the determination of methane,ethane,propane,propene,acetylene,iso-butane,propadiene,butane,trans-2-butene,butene-1,isobutene,cis-2-butene,methyl acetylene and 1,3-butadiene in high-purity ethylene.The purity of the ethylene can be calculated by subtracting thetotal percentage of all impurities from 100.00%.Since this testmethod does not determine all possible impurities such as CO,CO2,H2O,alcohols,nitrogen oxides,and carbonyl sulfide,aswell as hydrocarbons higher than decane,additional tests maybe necessary to fully characterize the ethylene sample.1.2 Data are reported in this test method as ppmV(parts permillion by volume).This test method was evaluated in aninterlaboratory cooperative study in the concentration range of4 to 340 ppmV(2 to 204 mg/kg).The participants in theinterlaboratory cooperative study reported the data in non-SIunits.Wherever possible,SI units are included.1.3 This standard dose 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 determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D2504 Test Method for Noncondensable Gases in C2andLighter Hydrocarbon Products by Gas ChromatographyD2505 Test Method for Ethylene,Other Hydrocarbons,andCarbon Dioxide in High-Purity Ethylene by Gas Chroma-tographyD5234 Guide for Analysis of Ethylene Product3.Summary of Test Method3.1 A gaseous ethylene sample is analyzed as received.Thegaseous sample is injected into a capillary gas chromatograph.A split-injector may or may not be used.The gas chromato-graph is provided with a 6port sampling valve and two widebore capillary columns connected in series.These columns area dimethyl silicone column and a(porous layer open tubularcolumn(PLOT)Al2O3/KCl column.3Aflame ionization detec-tor is used for detection.The integrated detector signal(peakareas)are corrected for detector response.The hydrocarbonimpurities are determined and the total impurities are used todetermine the ethylene content.4.Significance and Use4.1 High-purity ethylene is required as a feedstock for somemanufacturing processes and the presence of trace amounts ofcertain hydrocarbon impurities can have deleterious effects.This test method is suitable for setting specifications,for use asan internal quality control tool,and for use in development orresearch work.4.2 This test method does not detect such impurities as H2O,CO,CO2,and alcohols that may be present in the sample.Hydrocarbons higher than n-decane cannot be analyzed by thistest method,if present in the sample.Test Method D2504addresses the analysis of noncondensable gases and TestMethod D2505 addresses the analysis of CO2.Guide D5234describes all potential impurities present in ethylene.Thesestandards should be consulted when determining the totalconcentration of impurities in ethylene.5.Apparatus5.1 Gas Chromatograph(GC),a gas chromatographic in-strument provided with a temperature programmable columnoven and a flame ionization detector(FID).Regulate the carriergas by pressure control.5.2 DetectorUse a flame ionization detector(FID)havinga sensitivity of approximately 2.0 ppmV(1.2 mg/kg)or less forthe compounds listed in 1.1.An FID was exclusively used inthe interlaboratory cooperative study.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.D0.02 on Ethylene.Current edition approved Dec.1,2012.Published December 2012.Originallyapproved in 1997.Last previous edition approved in 2007 as D615997(2007).DOI:10.1520/D6159-97R12.2For 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.3This column is supplied by major column manufacturers.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 5.3 Column Temperature ProgrammerThe chromatographshall be capable of linear programmed temperature operationover a range sufficient for separation of the components ofinterest.Section 8 lists the recommended operating conditions.The programming rate shall be sufficiently reproducible toobtain retention repeatability of 0.05 min(3 s)throughout thescope of this analysis.5.4