1、Designation: D7679 13D7679 16Standard 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
2、. 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 instrumental determination of sulfur content in samples of carbon black feedstock oils. Valuesobtained
3、represent the total sulfur content. Two analysis methods are available for use:Test Method A: High-Temperature CombustionWithInfrared Absorption Detection ProceduresSections 4 10Test Method B: X-Ray Fluorescence Sections 13 171.2 This test method is applicable to carbon black feedstock oils derived
4、from petroleum, coal, and other sources which includefuel oils, residues, tars, pitches, reclaimed oils, and similar materials that are normally handled as liquids. This test method isapplicable to products typically containing 0 to 5 mass % sulfur.1.3 The results of these tests can be expressed as
5、mass % sulfur.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 address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard
6、to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D1619 Test Methods for Carbon BlackSulfur ContentD4057 Practice for Manual Sampling of Petroleum and Petroleum ProductsD4177 Practice
7、for Automatic Sampling of Petroleum and Petroleum ProductsD4483 Practice for Evaluating Precision for Test Method Standards in the Rubber and Carbon Black Manufacturing Industries3. Significance and Use3.1 Measuring the total sulfur content of feedstock oil is often a necessary component in calculat
8、ions for sulfur dioxideemissions.3.2 The carbon black industry measures sulfur content of feedstock oils along with sulfur content of carbon black products perTest Method D1619 in calculations to determine sulfur dioxide emissions for compliance with governmental reportingrequirements.TEST METHOD A:
9、 HIGH-TEMPERATURE COMBUSTION WITH INFRARED ABSORPTION DETECTIONPROCEDURES4. Summary of Test Method4.1 In this test method, a sample of feedstock oil is weighed in a combustion boat containing either a tungsten oxide basedaccelerator, sand or aluminum oxide absorbent, and the sulfur content is determ
10、ined by placing the boat in a tube furnace at 1350Cin an air or oxygen-enriched atmosphere resulting in complete combustion. Sulfur in the sample is completely oxidized to sulfur1 This test method is under the jurisdiction of ASTM Committee D24 on Carbon Black and is the direct responsibility of Sub
11、committee D24.66 on Environment, Health,and Safety.Current edition approved Nov. 1, 2013Jan. 1, 2016. Published December 2013February 2016. Originally approved in 2010. Last previous edition approved in 20112013as D7679 11.D7679 13. DOI: 10.1520/D7679-13.10.1520/D7679-16.2 For referencedASTM standar
12、ds, 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 Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM
13、 standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published b
14、y ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1dioxide. Moisture and particulates are removed from the gas stream by traps filled with anhydrous magnesium perchlorate. Thegas stream is
15、 then passed through a cell in which sulfur dioxide concentration is measured by an infrared (IR) absorption detectorat a precise wavelength in the IR spectrum. The IR absorption detects sulfur dioxide throughout the entire combustion process. Theintegral of the detector signal is the basis for the
16、total sulfur content of a sample.4.2 This test method is for use with commercially available sulfur analyzers equipped to carry out the combustion andmeasurement operations automatically.4.3 The sulfur analyzer shall be calibrated using appropriate calibration standards (see 6.7).4.4 The instrument
17、may be configured to analyze more than one element such as a carbon-sulfur analyzer. In this case, theanalyzer has individual detectors for each element that are arranged in series.5. Apparatus5.1 There are a number of commercially available instruments designed to measure sulfur content in organic
18、materials includingsulfur and carbon-sulfur combustion analyzers. This test method makes no specifications regarding system designs.5.2 Functionally, however, the following are specified for all instruments:5.2.1 An analytical balance, or equivalent, that is capable of a weighing sensitivity of 0.1
19、mg or better resolution.5.2.2 The combustion tube and boat are made of a suitable material such as mullite, porcelain, or zircon.5.2.3 The sample is absorbed onto a solid which may include the following materials: (1) tungsten oxide based accelerator; (2)Sea sand; (3) Aluminum oxide. Refer to the in
20、strument manufacturers recommendations.5.2.4 The sample is combusted at a temperature of 1350 6 15C in an air or oxygen-enriched atmosphere.5.2.5 The combustion gas is passed through an absorbent (anhydrous magnesium perchlorate) to remove water vapor.5.2.6 The detection system measures sulfur dioxi
21、de using an IR absorption detector at a wavelength suitable for linear responseswith respect to the concentration over the full range of possible concentrations.6. Reagents6.1 Purity of ReagentsReagent-grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that allrea
22、gents shall conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society wheresuch specifications are available.3 Other grades may be used, provided it is first ascertained that the reagent is of sufficiently highpurity to permit its use without lessening th
23、e accuracy of the determination.6.2 Magnesium Perchlorate.6.3 Oxygen, high purity, 99.9 %.6.4 Tungsten (VI) Oxide Accelerator, containing potassium dihydrogen-phosphate (optional).6.5 Sea Sand, purified by acid and calcinated (optional).6.6 Aluminum Oxide, optional.6.7 Calibration Standards. 47. Sam
24、pling7.1 Collect feedstock oil as specified in Practices D4057 or D4177.7.2 SampleThis is the portion or aliquot of the feedstock oil for use in obtaining a result.7.3 PreparationWarm viscous samples until they are fluid and shake for 5 s.7.4 TransferUse any convenient, clean syringe or pipet to tra
25、nsfer a sample to the combustion boat as described in Section10.8. Preparation of Apparatus8.1 Assemble the apparatus according to the manufacturers instructions.8.2 Stabilize the furnace temperature at 1350 6 15C.8.3 Make a minimum of two determinations to condition the equipment or follow the manu
26、facturers recommendation tocondition equipment before calibrating the instrument.3 Reagent Chemicals, American Chemical Society Specifications, American Chemical Society, Washington, DC. For Suggestions on the testing of reagents not listed bythe American Chemical Society, see Annual Standards for L
27、aboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and NationalFormulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.4 Sulfur calibration and reference standards are typically available from the instrument manufacturer, National Institute of Standar
28、ds and Technologys (NIST),http:/www.nist.gov, and are also available from Alpha Resources, 3090 Johnson Road, Stevensville, MI 49127, .D7679 1629. Calibration9.1 Calibrate the instrument per the manufacturers recommendation using appropriate sulfur calibration standards.9.2 Adjustment of Response of
29、 Measurement SystemWeigh approximately 0.1 to 0.2 g of calibration standard or use therecommended mass per manufacturer. Analyze the sample (see Section 10). Repeat this procedure. Adjust the instrument asrecommended by the manufacturer until the absence of drift is indicated. Insure the minimum ana
30、lysis time is sufficient forcomplete combustion of the sample.9.3 Calibration ProcedureFollow the calibration procedure recommended by the manufacturer. Confirm the calibration byanalyzing a reference material of known sulfur concentration. Reference standards should be similar to feedstock oils wit
31、h sulfurcontent in the range of approximately 0 to 5 %. The measured value should be within allowable limits of the known value. If not,repeat the procedure. If acceptable results are not obtained, refer to the manufacturers instructions for calibration.10. Procedure10.1 Stabilize and verify calibra
32、tion of the analyzer (see Sections 8 and 9).10.2 Confirm the furnace temperature is 1350 6 15C.10.3 Weigh an appropriate mass of accelerator or absorbent into the combustion boat.NOTE 1Use a material and mass recommended by the instrument manufacturer suitable for the combustion boat in use. Calibra
33、tion standards andfeedstock samples should be analyzed using a similar mass of accelerator or absorbent.10.4 Weigh approximately 0.1 to 0.2 g of the sample into the combustion boat on top of the accelerator or absorbent.10.5 Record the sample weight.10.6 A portion of the accelerator or absorbent wit
34、hin the boat may be used to cover the sample, or alternatively, additionalaccelerator or absorbent may be weighed and added to cover the sample.NOTE 2When covering the sample use care to insure none of the sample is accidentally removed from the combustion boat due to contact with aspatula or other
35、tool used to transfer or position the accelerator or absorbent.10.7 Initiate the analysis and place the boat in the instrument using a boat puller or an auto-sampler mechanism.10.8 When the analysis is complete, the instrument should indicate the sulfur value. Refer to the manufacturers recommendedp
36、rocedure.11. Report11.1 The percent sulfur value is obtained directly from the apparatus.11.2 Report results to the nearest 0.01 %.12. Precision and Bias512.1 These precision statements have been prepared in accordance with Practice D4483. Refer to this practice for terminologyand other statistical
37、details.12.2 The precision results in this precision and bias section give an estimate of the precision of this test method with thematerials used in the particular interlaboratory program described below. The precision parameters should not be used foracceptance or rejection testing of any group of
38、 materials without documentation that they are applicable to those particularmaterials and the specific testing protocols of the test method. Any appropriate value may be used from Table 1 for the HighTemperature Combustion Method A. An alternate combustion method for carbon content, CHNS, was inclu
39、ded in the5 A research report is pending.TABLE 1 Precision Parameters for Test Method D7679, Type 1 Precision, High Temperature Combustion, Sulfur Content of FeedstockUnitsPercentMaterial Number ofLaboratories Mean Level Sr r (r) SR R (R)9. Ethylene Cracker Residue 7 0.1378 0.0121 0.0343 24.92 0.017
40、5 0.0494 35.8810. NIST 1621e (0.95 % S) 7 0.9739 0.0195 0.0552 5.67 0.0435 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 9.2
41、7Average 2.2174Pooled Values 0.0448 0.127 5.72 0.093 0.263 11.85D7679 163interlaboratory program used to generate this precision statement since a few labs use this instrumental method. Precision dataspecific to the CHNS method is found in Table 2.12.3 A type 1 inter-laboratory precision program was
42、 conducted. Both repeatability and reproducibility represent short-term(daily) testing conditions. The testing was performed in each laboratory performing the test twice on each of two days (total offour tests). A test result is the value obtained from a single determination. Acceptable difference v
43、alues were not measured.12.4 The results of the precision calculations for this test are given 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), of this test has been establishe
44、d as 5.72 %. Any other value in Table1 may be used as an estimate of repeatability, as appropriate. The difference between two single test results (or determinations)found on identical test material under the repeatability conditions prescribed for this test will exceed the repeatability on an avera
45、geof not more than once in 20 cases in the normal and correct operation of the method. Two single test results that differ by morethan the appropriate value from Table 1 must be suspected of being from different populations and some appropriate action taken.NOTE 3Appropriate action may be an investi
46、gation of the test method procedure or apparatus for faulty operation or the declaration of a significantdifference in the two materials, samples, etc., which generated the two test results.12.6 ReproducibilityThe pooled relative reproducibility, (R) of this test has been established as 11.85 %. Any
47、 other value inTable 1 may be used as an estimate of reproducibility, as appropriate. The difference between two single and independent testresults found by operators working under the prescribed reproducibility conditions in different laboratories on identical testmaterial will exceed the reproduci
48、bility on an average of not more than once in 20 cases in the normal and correct operation ofthe method. Two single test results produced in different laboratories that differ by more than the appropriate value from Table 1must be suspected of being from different populations and some appropriate in
49、vestigative action taken.12.7 BiasIn test method terminology, bias is the difference between an average test value and the reference (true) test propertyvalue. Reference values do not exist for this test method since the value or level of the test property is exclusively defined by thetest method. Bias, therefore, cannot be determined.TEST METHOD B: X-RAY FLUORESCENCE13. Summary of Test Method13.1 X-ray fluorescence may be used to determine sulfur in carbon black feedstock oils. Each element has a unique energyresponse (fluore
