1、Designation: D7679 13Standard Test Method forSulfur Content in Carbon Black Feedstock Oils1This standard is issued under the fixed designation D7679; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A numb
2、er 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 instrumental determinationof sulfur content in samples of carbon black feedstock oils.Values obtained represent
3、 the total sulfur content. Two analysismethods are available for use:Test Method A: High-Temperature CombustionWithInfrared Absorption Detection ProceduresSections 410Test Method B: X-Ray Fluorescence Sections 13171.2 This test method is applicable to carbon black feedstockoils derived from petroleu
4、m, coal, and other sources whichinclude fuel oils, residues, tars, pitches, reclaimed oils, andsimilar materials that are normally handled as liquids. This testmethod is applicable to products typically containing 0 to 5mass % sulfur.1.3 The results of these tests can be expressed as mass %sulfur.1.
5、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 concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-
6、priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D1619 Test Methods for Carbon BlackSulfur ContentD4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD4177 Practice for Automatic Sam
7、pling of Petroleum andPetroleum ProductsD4483 Practice for Evaluating Precision for Test MethodStandards in the Rubber and Carbon Black ManufacturingIndustries3. Significance and Use3.1 Measuring the total sulfur content of feedstock oil isoften a necessary component in calculations for sulfur dioxi
8、deemissions.3.2 The carbon black industry measures sulfur content offeedstock oils along with sulfur content of carbon blackproducts per Test Method D1619 in calculations to determinesulfur dioxide emissions for compliance with governmentalreporting requirements.TEST METHOD A: HIGH-TEMPERATURECOMBUS
9、TION WITH INFRARED ABSORPTIONDETECTION PROCEDURES4. Summary of Test Method4.1 In this test method, a sample of feedstock oil is weighedin a combustion boat containing either a tungsten oxide basedaccelerator, sand or aluminum oxide absorbent, and the sulfurcontent is determined by placing the boat i
10、n a tube furnace at1350C in an air or oxygen-enriched atmosphere resulting incomplete combustion. Sulfur in the sample is completelyoxidized to sulfur dioxide. Moisture and particulates areremoved from the gas stream by traps filled with anhydrousmagnesium perchlorate. The gas stream is then passed
11、througha cell in which sulfur dioxide concentration is measured by aninfrared (IR) absorption detector at a precise wavelength in theIR spectrum. The IR absorption detects sulfur dioxide through-out the entire combustion process. The integral of the detectorsignal is the basis for the total sulfur c
12、ontent of a sample.4.2 This test method is for use with commercially availablesulfur analyzers equipped to carry out the combustion andmeasurement operations automatically.4.3 The sulfur analyzer shall be calibrated using appropriatecalibration standards (see 6.7).4.4 The instrument may be configure
13、d to analyze more thanone element such as a carbon-sulfur analyzer. In this case, theanalyzer has individual detectors for each element that arearranged in series.1This test method is under the jurisdiction of ASTM Committee D24 on CarbonBlack and is the direct responsibility of Subcommittee D24.66
14、on Environment,Health, and Safety.Current edition approved Nov. 1, 2013. Published December 2013. Originallyapproved in 2010. Last previous edition approved in 2011 as D7679 11. DOI:10.1520/D7679-13.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service
15、 at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15. Apparatus5.1 There are a number of commercial
16、ly available instru-ments designed to measure sulfur content in organic materialsincluding sulfur and carbon-sulfur combustion analyzers. Thistest method makes no specifications regarding system designs.5.2 Functionally, however, the following are specified for allinstruments:5.2.1 An analytical bal
17、ance, or equivalent, that is capable ofa weighing sensitivity of 0.1 mg or better resolution.5.2.2 The combustion tube and boat are made of a suitablematerial such as mullite, porcelain, or zircon.5.2.3 The sample is absorbed onto a solid which mayinclude the following materials: (1) tungsten oxide
18、basedaccelerator; (2) Sea sand; (3) Aluminum oxide. Refer to theinstrument manufacturers recommendations.5.2.4 The sample is combusted at a temperature of 1350 615C in an air or oxygen-enriched atmosphere.5.2.5 The combustion gas is passed through an absorbent(anhydrous magnesium perchlorate) to rem
19、ove water vapor.5.2.6 The detection system measures sulfur dioxide using anIR absorption detector at a wavelength suitable for linearresponses with respect to the concentration over the full rangeof possible concentrations.6. Reagents6.1 Purity of ReagentsReagent-grade chemicals shall beused in all
20、tests. Unless otherwise indicated, it is intended thatall reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Societywhere such specifications are available.3Other grades may beused, provided it is first ascertained that the reagent is ofsuf
21、ficiently high purity to permit its use without lessening theaccuracy of the determination.6.2 Magnesium Perchlorate.6.3 Oxygen, high purity, 99.9 %.6.4 Tungsten (VI) Oxide Accelerator, containing potassiumdihydrogen-phosphate (optional).6.5 Sea Sand, purified by acid and calcinated (optional).6.6 A
22、luminum Oxide, optional.6.7 Calibration Standards.47. Sampling7.1 Collect feedstock oil as specified in Practices D4057 orD4177.7.2 SampleThis is the portion or aliquot of the feedstockoil for use in obtaining a result.7.3 PreparationWarm viscous samples until they are fluidand shake for 5 s.7.4 Tra
23、nsferUse any convenient, clean syringe or pipet totransfer a sample to the combustion boat as described inSection 10.8. Preparation of Apparatus8.1 Assemble the apparatus according to the manufacturersinstructions.8.2 Stabilize the furnace temperature at 1350 6 15C.8.3 Make a minimum of two determin
24、ations to condition theequipment or follow the manufacturers recommendation tocondition equipment before calibrating the instrument.9. Calibration9.1 Calibrate the instrument per the manufacturers recom-mendation using appropriate sulfur calibration standards.9.2 Adjustment of Response of Measuremen
25、t SystemWeigh approximately 0.1 to 0.2 g of calibration standard or usethe recommended mass per manufacturer. Analyze the sample(see Section 10). Repeat this procedure. Adjust the instrumentas recommended by the manufacturer until the absence of driftis indicated. Insure the minimum analysis time is
26、 sufficient forcomplete combustion of the sample.9.3 Calibration ProcedureFollow the calibration proce-dure recommended by the manufacturer. Confirm the calibra-tion by analyzing a reference material of known sulfur con-centration. Reference standards should be similar to feedstockoils with sulfur c
27、ontent in the range of approximately 0 to 5 %.The measured value should be within allowable limits of theknown value. If not, repeat the procedure. If acceptable resultsare not obtained, refer to the manufacturers instructions forcalibration.10. Procedure10.1 Stabilize and verify calibration of the
28、analyzer (seeSections 8 and 9).10.2 Confirm the furnace temperature is 1350 6 15C.10.3 Weigh an appropriate mass of accelerator or absorbentinto the combustion boat.NOTE 1Use a material and mass recommended by the instrumentmanufacturer suitable for the combustion boat in use. Calibration stan-dards
29、 and feedstock samples should be analyzed using a similar mass ofaccelerator or absorbent.10.4 Weigh approximately 0.1 to 0.2 g of the sample intothe combustion boat on top of the accelerator or absorbent.10.5 Record the sample weight.10.6 A portion of the accelerator or absorbent within theboat may
30、 be used to cover the sample, or alternatively,additional accelerator or absorbent may be weighed and addedto cover the sample.NOTE 2When covering the sample use care to insure none of thesample is accidentally removed from the combustion boat due to contactwith a spatula or other tool used to trans
31、fer or position the accelerator orabsorbent.3Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For Suggestions on the testing of reagents notlisted by the American Chemical Society, see Annual Standards for LaboratoryChemicals, BDH Ltd., Poole, Do
32、rset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.4Sulfur calibration and reference standards are typically available from theinstrument manufacturer, National Institute of Standards and Technologys (NIST),http:/www.nist.go
33、v, and are also available from Alpha Resources, 3090 JohnsonRoad, Stevensville, MI 49127, .D7679 13210.7 Initiate the analysis and place the boat in the instru-ment using a boat puller or an auto-sampler mechanism.10.8 When the analysis is complete, the instrument shouldindicate the sulfur value. Re
34、fer to the manufacturers recom-mended procedure.11. Report11.1 The percent sulfur value is obtained directly from theapparatus.12. Precision and Bias512.1 These precision statements have been prepared inaccordance with Practice D4483. Refer to this practice forterminology and other statistical detai
35、ls.12.2 The precision results in this precision and bias sectiongive an estimate of the precision of this test method with thematerials used in the particular interlaboratory program de-scribed below. The precision parameters should not be used foracceptance or rejection testing of any group of mate
36、rialswithout documentation that they are applicable to those par-ticular materials and the specific testing protocols of the testmethod. Any appropriate value may be used from Table 1 forthe High Temperature Combustion Method A. An alternatecombustion method for carbon content, CHNS, was included in
37、the interlaboratory program used to generate this precisionstatement since a few labs use this instrumental method.Precision data specific to the CHNS method is found in Table2.12.3 A type 1 inter-laboratory precision program was con-ducted. Both repeatability and reproducibility represent short-ter
38、m (daily) testing conditions. The testing was performed ineach laboratory performing the test twice on each of two days(total of four tests). A test result is the value obtained from asingle determination. Acceptable difference values were notmeasured.12.4 The results of the precision calculations f
39、or this test aregiven in Table 1 for the High Temperature Combustion MethodA. The materials are arranged in ascending “mean level” order.12.5 RepeatabilityThe pooled relative repeatability, (r), ofthis test has been established as 5.72 %. Any other value inTable 1 may be used as an estimate of repea
40、tability, asappropriate. The difference between two single test results (ordeterminations) found on identical test material under therepeatability conditions prescribed for this test will exceed therepeatability on an average of not more than once in 20 casesin the normal and correct operation of th
41、e method. Two singletest results that differ by more than the appropriate value fromTable 1 must be suspected of being from different populationsand some appropriate action taken.NOTE 3Appropriate action may be an investigation of the test methodprocedure or apparatus for faulty operation or the dec
42、laration of asignificant difference in the two materials, samples, etc., which generatedthe two test results.12.6 ReproducibilityThe pooled relative reproducibility,(R) of this test has been established as 11.85 %. Any othervalue in Table 1 may be used as an estimate of reproducibility,as appropriat
43、e. The difference between two single and inde-pendent test results found by operators working under theprescribed reproducibility conditions in different laboratorieson identical test material will exceed the reproducibility on anaverage of not more than once in 20 cases in the normal andcorrect ope
44、ration of the method. Two single test resultsproduced in different laboratories that differ by more than theappropriate value from Table 1 must be suspected of beingfrom different populations and some appropriate investigativeaction taken.5A research report is pending.TABLE 1 Precision Parameters fo
45、r Test Method D7679, Type 1 Precision, High Temperature Combustion, Sulfur Content of FeedstockUnitsPercentMaterialNumber ofLaboratoriesMean Level Sr r (r) SR R (R)9. Ethylene Cracker Residue 7 0.1378 0.0121 0.0343 24.92 0.0175 0.0494 35.8810. NIST 1621e (0.95 % S) 7 0.9739 0.0195 0.0552 5.67 0.0435
46、 0.1232 12.6511. NIST 1622e (2.1 % S) 7 2.2038 0.0298 0.0843 3.83 0.1007 0.2851 12.9312. NIST 2717a (3.0 % S) 7 3.0525 0.0322 0.0911 2.98 0.0827 0.2341 7.6713. NIST 1620c (4.6 % S) 7 4.7190 0.0872 0.2467 5.23 0.1546 0.4376 9.27Average 2.2174Pooled Values 0.0448 0.127 5.72 0.093 0.263 11.85TABLE 2 Pr
47、ecision Parameters for Test Method D7679, Type 1 Precision, CHNS, Sulfur Content of FeedstockUnitsPercentMaterialNumber ofLaboratoriesMean Level Sr r (r) SR R (R)9. Ethylene Cracker Residue 5 0.1140 0.0170 0.0482 42.27 0.0312 0.0884 77.5410. NIST 1621e (0.95 % S) 6 0.9279 0.0295 0.0834 8.99 0.1219 0
48、.3451 37.1911. NIST 1622e (2.1 % S) 6 2.0917 0.0560 0.1585 7.58 0.1531 0.4331 20.7112. NIST 2717a (3.0 % S) 6 2.9788 0.0513 0.1453 4.88 0.0970 0.2745 9.2213. NIST 1620c (4.6 % S) 6 4.5825 0.0539 0.1524 3.33 0.1686 0.4772 10.41Average 2.1390Pooled Values 0.0443 0.1255 5.87 0.1242 0.3515 16.43D7679 13
49、312.7 BiasIn test method terminology, bias is the differencebetween an average test value and the reference (true) testproperty value. Reference values do not exist for this testmethod since the value or level of the test property isexclusively defined by the test method. Bias, therefore, cannotbe determined.TEST METHOD B: X-RAY FLUORESCENCE13. Summary of Test Method13.1 X-ray fluorescence may be used to determine sulfur incarbon black feedstock oils. Each element has a unique energyresponse (fluorescence) when exposed to x-ray ener
