1、Designation: D5622 16D5622 17Standard Test Methods forDetermination of Total Oxygen in Gasoline and MethanolFuels by Reductive Pyrolysis1This standard is issued under the fixed designation D5622; the number immediately following the designation indicates the year oforiginal adoption or, in the case
2、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. Scope*1.1 These test methods cover the quantitative determination of total oxygen in gasoline and meth
3、anol fuels by reductivepyrolysis.1.2 Precision data are provided for 1.0 % to 5.0 % oxygen by mass in gasoline and for 40 % to 50 % oxygen by mass inmethanol fuels.1.3 Several types of instruments can be satisfactory for these test methods. Instruments can differ in the way that theoxygen-containing
4、 species is detected and quantitated. However, these test methods are similar in that the fuel is pyrolyzed in acarbon-rich environment.1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.5 This standard does not purport to
5、address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.1.6 This international standard was developed in accord
6、ance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Sta
7、ndards:2D1298 Test Method for Density, Relative Density, or API Gravity of Crude Petroleum and Liquid Petroleum Products byHydrometer MethodD4052 Test Method for Density, Relative Density, and API Gravity of Liquids by Digital Density MeterD4057 Practice for Manual Sampling of Petroleum and Petroleu
8、m ProductsD4177 Practice for Automatic Sampling of Petroleum and Petroleum ProductsD4815 Test Method for Determination of MTBE, ETBE, TAME, DIPE, tertiary-Amyl Alcohol and C1 to C4 Alcohols inGasoline by Gas Chromatography2.2 Other Standards:Clean Air Act (1992)33. Summary of Test Method3.1 Afuel sp
9、ecimen of 1 Lto 10 Lis injected by syringe into a 950 C to 1300 C high-temperature tube furnace that containsmetallized carbon. Oxygen-containing compounds are pyrolyzed, and the oxygen is quantitatively converted into carbonmonoxide.3.2 A carrier gas, such as nitrogen, helium, or a helium/hydrogen
10、mixture, sweeps the pyrolysis gases into any of fourdownstream systems of reactors, scrubbers, separators, and detectors for the determination of the carbon monoxide content, henceof the oxygen in the original fuel sample. The result is reported as mass % oxygen in the fuel.1 These test methods are
11、under the jurisdiction of Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and are the direct responsibility of SubcommitteeD02.03 on Elemental Analysis.Current edition approved June 1, 2016May 1, 2017. Published June 2016May 2017. Originally approved in 1994. Last previous edition
12、approved in 20112016 asD5622 95 (2011).D5622 16. DOI: 10.1520/D5622-16.10.1520/D5622-17.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summar
13、y page on the ASTM website.3 Federal Register, Vol 57, No. 24, Feb. 5, 1992, p. 4408.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to a
14、dequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright AS
15、TM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States14. Significance and Use4.1 These test methods cover the determination of total oxygen in gasoline and methanol fuels, and they complement TestMethod D4815, which covers the determination of several
16、specific oxygen-containing compounds in gasoline.4.2 The presence of oxygen-containing compounds in gasoline can promote more complete combustion, which reduces carbonmonoxide emissions. The Clean Air Act (1992) requires that gasoline sold within certain,certain specified geographical areascontain a
17、 minimum percent of oxygen by mass (presently 2.7 mass 2.7 mass %) during certain portions of the year. Therequirement can be met by blending compounds such as methyl tertiary butyl ether, ethyl tertiary butyl ether, and ethanol into thegasoline. These test methods cover the quantitative determinati
18、on of total oxygen which is the regulated parameter.4.2.1 Only seven U.S. states have such wintertime requirements, and others with EPA approval have opted out of the program.The minimum oxygen limit now varies from 1.8 % to 3.5 % by mass. For methanol/heavier alcohol blend EPA waivers, themaximum o
19、xygen content allowed is 3.5 % or 3.7 % by mass.4.2.1.1 Only ethanol is used for such blending in the U.S. Ethers are banned by some states and are not used in all states becauseof water contamination issues.5. Apparatus5.1 Oxygen Elemental Analyzer4,5,6,7,8A variety of instrumentation can be satisf
20、actory. However, the instrument mustreductively pyrolize the specimen and convert oxygen to carbon monoxide.5.1.1 Test Method A4,8Helium carrier gas transports the pyrolysis products through a combination scrubber to remove acidicgases and water vapor. The products are then transported to a molecula
21、r sieve gas chromatographic column where the carbonmonoxide is separated from the other pyrolysis products.Athermal conductivity detector generates a response that is proportionalto the amount of carbon monoxide.5.1.2 Test Method B5,8Nitrogen carrier gas transports the pyrolysis products through a s
22、crubber to remove water vapor. Thepyrolysis products then flow through tandem infrared detectors that measure carbon monoxide and carbon dioxide, respectively.5.1.3 Test Method C6,8Amixture of helium and hydrogen (95:5 %), helium, or argon transports the pyrolysis products throughtwo reactors in ser
23、ies. The first reactor contains heated copper which removes sulfur-containing products. The second reactorcontains a scrubber which removes acidic gases and a reactant which oxidizes carbon monoxide to carbon dioxide (optional). Theproduct gases are then homogenized in a mixing chamber, which mainta
24、ins the reaction products at absolute conditions oftemperature, pressure, and volume. The mixing chamber is subsequently depressurized through a column that separates carbonmonoxide (or carbon dioxide, if operating in the oxidation mode) from interfering compounds. A thermal conductivity detectormea
25、sures a response proportional to the amount of carbon monoxide or carbon dioxide.5.1.4 Test Method D7,8Nitrogen carrier gas transports the pyrolysis products through scrubbers to remove acidic gases andwater vapor. A reactor containing cupric oxide at 325 C oxidizes the carbon monoxide to carbon dio
26、xide, which in turn istransported into a coulometric carbon dioxide detector. Coulometrically generated base titrates the acid formed by reacting carbondioxide with monoethanolamine.5.2 A technique must be established to make a quantitative introduction of the test specimen into the analyzer. Specim
27、en vialsand transfer labware must be clean and dry.5.3 For instruments that measure carbon monoxide only, pyrolysis conditions must be established to quantitatively convertoxygen to carbon monoxide.5.4 A system of scrubbers and separators must be established to effectively remove pyrolysis products
28、that interfere with thedetection of carbon monoxide or carbon dioxide, or both.5.5 The detector responses must be linear with respect to concentration, or nonlinear responses must be detectable andaccurately related to concentration.5.6 Selected items are available from the instrument manufacturer.5
29、.6.1 Pyrolysis tubes,5.6.2 Scrubber tubes, and5.6.3 Absorber Tubes.tubes.4 The sole source of supply of the apparatus (Thermo Scientific formerly known as Carlo Erba Models 1108, 1110, now FLASH 1112 and FLASH 2000) known to thecommittee at this time is CE Elantech, Inc., 170 Oberlin Ave. N., Ste 5,
30、 Lakewood, NJ 08701.5 The sole source of supply of the apparatus (Leco Model RO-478) known to the committee at this time is Leco Corp., 3000 Lakeview Ave., St. Joseph, MI 49085.6 The sole source of supply of the apparatus (Perkin-Elmer Series 2400) known to the committee at this time is Perkin-Elmer
31、 Corp., 761 Main Ave., Norwalk, CT 06859.7 The sole source of supply of the apparatus (UIC, Inc./Coulometrics Model 5012 CO2 coulometer and Model 5220 autosampler-furnace) known to the committee at thistime is UIC Inc., Box 863, Joliet, IL 60434.8 If you are aware of alternative suppliers, please pr
32、ovide this information to ASTM International Headquarters. Your comments will receive careful consideration at ameeting of the responsible technical committee,1 which you may attend.D5622 1726. Reagents6.1 Purity of Reagents9Reagent grade Reagent-grade chemicals shall be used in all tests. Unless ot
33、herwise indicated, it isintended that all reagents conform to the specifications of the Committee onAnalytical Reagents of theAmerican Chemical Societywhere such specifications are available. Other grades may be used, provided it is first ascertained that the reagent is of sufficientlyhigh purity to
34、 permit its use without lessening the accuracy of the determination.6.2 Calibration Standards:6.2.1 NIST SRM 1837,10which contains certified concentrations of methanol and t-butanol in reference fuel, can be used tocalibrate the instrument for the analysis of oxygenates in gasoline.6.2.1 Anhydrous m
35、ethanol, 99.8 % minimum assay, can be used to calibrate the instrument for the analysis of methanol fuels.6.2.2 Isooctane, or other hydrocarbons, can be used as the blank provided the purity is satisfactory.6.3 Quality Control StandardNIST SRM 183810 can be used to check the accuracy of the calibrat
36、ion.6.3 The instrument manufacturers require additional reagents.6.3.1 Test Method A:4,84,86.3.1.1 Anhydrone (anhydrous magnesium perchlorate),6.3.1.2 Ascarite II (sodium hydroxide on silica),6.3.1.3 Helium carrier gas, 99.995 % pure,6.3.1.4 Molecular sieve, 5, 60 to 80 mesh,6.3.1.5 Nickel wool,6.3.
37、1.6 Nickelized carbon, 20 % loading,6.3.1.7 Quartz chips, and6.3.1.8 Quartz wool.6.3.2 Test Method B:5,86.3.2.1 Anhydrone (anhydrous magnesium perchlorate),6.3.2.2 Carbon pyrolysis pellets, and6.3.2.3 Nitrogen carrier gas, 99.99 % pure.6.3.3 Test Method C:6,86.3.3.1 Anhydrone (anhydrous magnesium pe
38、rchlorate),6.3.3.2 Ascarite II (sodium hydroxide on silica),6.3.3.3 Carrier gas, either helium (95 %)hydrogen (5 %), mixture, 99.99 % pure; helium, 99.995 % pure; or argon, 99.98 %pure,6.3.3.4 Copper plus, wire form, and6.3.3.5 Platinized carbon.6.3.4 Test Method D:7,86.3.4.1 Anhydrone (anhydrous ma
39、gnesium perchlorate),6.3.4.2 Ascarite II (sodium hydroxide on silica),6.3.4.3 Copper (II) oxide,6.3.4.4 Coulometric cell solutions, including a cathode solution of monoethanolamine in dimethyl sulfoxide and an anodesolution of water and potassium iodide in dimethyl sulfoxide,6.3.4.5 Nickelized carbo
40、n, 20 % loading, and6.3.4.6 Nitrogen carrier gas, 99.99 % pure.7. Sampling7.1 Take samples in accordance with the instructions in Practices D4057 or D4177.7.2 Visually inspect the samples, and when there is evidence of nonuniformity, take fresh samples.7.3 Store the samples in a cold room or a labor
41、atory refrigerator designed for storage of chemicals.8. Preparation of Apparatus8.1 Prepare the instrument in accordance with the manufacturers recommendations. These test methods require that correctoperating procedures are followed for the model used. Instrument design differences make it impracti
42、cal to specify all of therequired operating conditions.8.2 The carrier gas can be scrubbed to remove traces of oxygen and oxygen-containing compounds.9 Reagent Chemicals, American Chemical Society Specifications, American Chemical Society, Washington, DC. For Suggestions on the testing of reagents n
43、ot listed bythe American Chemical Society, see Annual Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and NationalFormulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.D5622 1739. Calibration and Standardization9.1 Calibration for
44、Test Methods A, B, and C, Oxygenates in Gasoline:9.1.1 Use a syringe to introduce 1 L to 10 L, or 1 mg to 10 mg, of the blank. The amount of specimen must be preciselyknown. Measure the response. Repeat the introduction and measurement until stable readings are observed.9.1.2 In a similar fashion, i
45、ntroduce 1 L to 10 L, or 1 mg to 10 mg, of SRM 1837an appropriate quantity of calibrationstandard and measure the response. Repeat two times with the same quantity of the SRM. calibration standard. If the blankcorrected responses do not agree within 2 % relative, take corrective action and repeat th
46、e calibration.9.1.3 Calculate the K-factor as follows:K5Cstd 3MstdRavg(1)where:where:Cstd = mass % oxygen in the SRM,Cstd = mass % oxygen in the calibration standard,Mstd = mass of the SRM, mg,Mstd = mass of the calibration standard, mg,= volume of the SRM (L) density of the SRM (g/mL), and= volume
47、of the calibration standard (L) density of the calibration standard (g/mL), andRavg = average of the blank corrected responses.NOTE 1Density can be determined by Test Method D1298 or Test Method D4052.9.2 Calibration for Test Methods A, B, and C, Methanol FuelsRepeat procedure 9.1; however, substitu
48、te anhydrous methanolfor the SRM. calibration standard used. For methanol fuels, a unique K-factor can be necessary.9.3 Calibration for Test Method DThis test method does not require calibration; however, a quality control standard must beanalyzed to ensure proper operation of the instrument. A blan
49、k must also be analyzed periodically to ensure consistent responses.9.4 Quality Control (QC):9.4.1 Introduce the QC standard SRM 1838in the same manner as the calibration standards. Calculate the percent oxygen (m/m)as described in Section 10.9.4.2 When results obtained on the QC standard do not agree with the certified values within 2 % relative, take corrective actionand repeat the calibration and quality control.9.4.3 ForTest Method D, when the recovery of oxygen from the QC SRMsample is less than 0.85 (that is, 85 %), take correctiveaction and r
