ASTM D6667-2014 red 3374 Standard Test Method for Determination of Total Volatile Sulfur in Gaseous Hydrocarbons and Liquefied Petroleum Gases by Ultraviolet Fluorescence《用紫外荧光法测定气.pdf

1、Designation: D6667 10D6667 14Standard Test Method forDetermination of Total Volatile Sulfur in GaseousHydrocarbons and Liquefied Petroleum Gases by UltravioletFluorescence1This standard is issued under the fixed designation D6667; the number immediately following the designation indicates the year o

2、foriginal 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. Scope*1.1 This test method covers the determination of total volati

3、le sulfur in gaseous hydrocarbons and liquefied petroleum (LP)gases. It is applicable to analysis of natural, processed, and final product materials containing sulfur in materials. Precision has beendetermined for sulfur in gaseous hydrocarbons in the range of 1 mg/kg to 100 mg/kg and for sulfur in

4、LP gases in the range of1 mg/kg to 196 mg/kg (Note 1).NOTE 1An estimate of pooled limit of quantification (PLOQ), information regarding sample stability and other general information derived from theinter-laboratory studyinterlaboratory studies on precision can be referenced in the ASTM research rep

5、ort.reports.2,31.2 This test method may not detect sulfur compounds that do not vaporize under the conditions of the test.1.3 This test method is applicable for total volatile sulfur determination in LP gases containing less than 0.35 % (mass/mass)halogen(s).1.4 The values stated in SI units are to

6、be regarded as 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 to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior

7、to use. See 3.1 and Sections 6 and 7 for specific warning statements.2. Referenced Documents2.1 ASTM Standards:4D1070 Test Methods for Relative Density of Gaseous FuelsD1265 Practice for Sampling Liquefied Petroleum (LP) Gases, Manual MethodD3700 Practice for Obtaining LPG Samples Using a Floating P

8、iston CylinderD5287 Practice for Automatic Sampling of Gaseous FuelsD6299 Practice for Applying Statistical Quality Assurance and Control Charting Techniques to Evaluate Analytical Measure-ment System PerformanceF307 Practice for Sampling Pressurized Gas for Gas Analysis2.2 Gas Processor Association

9、 (GPA) Standards:5GPA 2166 Obtaining Natural Gas Samples for Analysis by Gas ChromatographyGPA 2174 Obtaining Liquid Hydrocarbon Samples for Analysis by Gas Chromatography3. Summary of Test Method3.1 A heated sample valve is used to inject gaseous samples. Liquefied petroleum gas (LPG) samples are i

10、njected by a samplevalve connected to a heated expansion chamber. The gaseous sample then enters a high temperature combustion tube where sulfur1 This test method is under the jurisdiction of ASTM Committee D02 on Petroleum Products Products, Liquid Fuels, and Lubricants and is the direct responsibi

11、lity ofSubcommittee D02.03 on Elemental Analysis.Current edition approved Oct. 1, 2010Oct. 1, 2014. Published November 2010October 2014. Originally approved in 2001. Last previous edition approved in 2010 asD666704(2010).D6667 10. DOI: 10.1520/D6667-10.10.1520/D6667-14.2 Supporting data have been fi

12、led at ASTM International Headquarters and may be obtained by requesting Research Report RR:D02-1506. Contact ASTM CustomerService at serviceastm.org.3 Supporting data have been filed at ASTM International Headquarters and may be obtained by requesting Research Report RR:D02-1784. Contact ASTM Custo

13、merService at serviceastm.org.4 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 Summary page on the ASTM website.5 Available from Gas Processors

14、 Association (GPA), 6526 E. 60th St., Tulsa, OK 74145.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 adequately depict all changes ac

15、curately, 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 ASTM International, 100 Barr Harb

16、or Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1is oxidized to sulfur dioxide (SO2) in an oxygen rich atmosphere. Water produced during the sample combustion is removed andthe sample combustion gases are next exposed to ultraviolet (UV) light. The SO2 absorbs the energy from t

17、he UV light and isconverted to an excited sulfur dioxide (SO2). Fluorescence emitted from the excited SO2* as it returns to a stable state SO2* isdetected by a photomultiplier tube, the resulting signal is a measure of the sulfur contained in the sample. (WarningExposureto excessive quantities of ul

18、traviolet light is injurious to health. The operator shall avoid exposing their person, especially theireyes, not only to direct UV light but also to secondary or scattered radiation that is present.)4. Significance and Use4.1 The sulfur content of LPG, used for fuel purposes, contributes to SOx emi

19、ssions and can lead to corrosion in engine andexhaust systems. Some process catalysts used in petroleum and chemical refining can be poisoned by sulfur bearing materials inthe feed stocks. This test method can be used to determine sulfur in process feeds, to measure sulfur in finished products, and

20、canalso be used for compliance determinations when acceptable to a regulatory authority.5. Apparatus5.1 FurnaceAn electric furnace held at a temperature (1075 6 25C) sufficient to pyrolyze the entire sample and oxidizesulfur to SO2.5.2 Combustion TubeA quartz combustion tube constructed to allow the

21、 direct injection of the sample into the heatedoxidation zone of the furnace. The combustion tube shall have side arms for the introduction of oxygen and carrier gas. Theoxidation section shall be large enough (see Fig. 1) to ensure complete combustion of the sample (see 11.3). Fig. 1 depicts a typi

22、calcombustion tube. Other configurations are acceptable when precision is not degraded.5.3 Flow ControlThe apparatus shall be equipped with flow controllers capable of maintaining a constant supply of oxygenand carrier gas at the specified rates.5.4 Drier TubeThe apparatus shall be equipped with a m

23、echanism for the removal of water vapor formed during samplecombustion. This can be accomplished with a membrane drying tube, or a permeation dryer that utilizes a selective capillary actionfor water removal.5.5 UV Fluorescence DetectorA quantitative detector capable of measuring light emitted from

24、the fluorescence of sulfurdioxide by UV light.5.6 Sample Inlet SystemThe system provides a heated gas-sampling valve, or a LP gas-sampling valve, or both, with a heatedexpansion chamber, connected to the inlet of the oxidation area, Fig. 2. The system is swept by an inert carrier gas and shall becap

25、able of allowing the quantitative delivery of the material to be analyzed into the oxidation zone at a controlled and repeatablerate of approximately 30 mL/min. Fig. 3 provides an example.5.7 Strip Chart Recorder, equivalent electronic data logger, integrator or, recorder (optional).FIG. 1 Example o

26、f a Typical Direct Inject Quartz Pyrolysis TubeD6667 142FIG. 2 Example of Orientation of Total Sulfur Analyzer and Gas or Liquid Sampling ValveFIG. 3 Sample Inlet System Flow PathD6667 1436. Reagents6.1 Purity of ReagentsReagent grade chemicals shall be used in tests. Unless otherwise indicated, it

27、is intended that allreagents shall conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society,6 wheresuch specifications are available. Other grades may be used, provided it is first ascertained that the reagent is of sufficiently highpurity to permit its

28、use without lessening the accuracy of the determination.6.2 Inert GasArgon or helium only, high purity grade (that is, chromatography or zero grade), 99.998 % min purity, moisture5 mg/kg max. (Warning Argon or helium may be a compressed gas under high pressure (7.1).6.3 OxygenHigh purity (that is ch

29、romatography or zero grade), 99.75 % min purity, moisture 5 mg/kg max, dried overmolecular sieves. (WarningOxygen vigorously accelerates combustion and may be compressed gas under high pressure (7.1).6.4 Calibration StandardsCertified calibration standards from commercial sources or calibration gase

30、s prepared usingcertified permeation tube devices are required. Table 1 lists the sulfur source material and diluent matrices used during theinter-laboratory study (Notes 2 and 3).NOTE 2Other sulfur sources and diluent materials may be used if precision and accuracy are not degraded.NOTE 3Calibratio

31、n standards are typically re-mixed and re-certified on a regular basis depending upon frequency of use and age. These calibrationstandards may have a useful life of about 6 to 12 months.6.5 Quality Control (QC) Samples, preferably are portions of one or more gas or LP gas materials that are stable a

32、ndrepresentative of the samples of interest.7. Hazards7.1 High temperature, flammable hydrocarbons, and gases under high pressures occur in the test method. Use materials that arerated for containing these pressurized hydrocarbons in all sample containers and sample transfer apparatus. Exercise extr

33、a carewhen using flammable materials near the oxidative furnace.8. Sampling8.1 Obtain a sample in accordance with Practices F307, D1265, D3700, D5287, or GPA 2174 or GPA 2166. Analyze samplesas soon as possible after taking from bulk supplies to prevent loss of sulfur or contamination due to exposur

34、e or contact withsample containers.8.2 If the sample is not used immediately, then thoroughly mix it in its container prior to taking a test specimen. The use ofsegregated or specially treated sample containers can help reduce sample cross-contamination and improve sample stability.9. Preparation of

35、 Apparatus9.1 Assemble and check the apparatus for leaks according to manufacturers instructions.9.2 Typical apparatus adjustments and conditions are listed in Table 2.9.3 Adjust instrument sensitivity and baseline stability and perform instrument-blanking procedures following manufacturersguideline

36、s.10. Calibration and Standardization10.1 Consult Table 3 and select a calibration range based on the anticipated sulfur concentrations present in samples to beanalyzed, preferably using a sulfur compound and a diluent type representative of the samples to be analyzed (Note 4). Table 3is representat

37、ive of typical ranges, but narrower ranges than those indicated may be used if desired. However, the method precisionusing narrower ranges than those indicated has not been determined. Ensure the standards used for calibration bracket theconcentrations of the samples being analyzed.NOTE 4The number

38、of standards used per curve may vary.6 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 Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset

39、, U.K., and the United States Pharmacopeia and NationalFormulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.TABLE 1 Typical Standard MaterialsSulfur Source DiluentDimethyl sulfide n, butaneiso-butanepropylenepropaneD6667 14410.2 With the sample valve in the load position, connect the

40、 pressurized sample container to the sample valve of the sampleinlet system.10.3 Obtain a quantitative measurement of the injected material by filling the sample loop of the sample valve system for thematrix being analyzed (see Table 2) (Notes 5 and 6).NOTE 5Injection of a constant or similar sample

41、 size for all materials analyzed in a selected operating range promotes consistent combustionconditions and may simplify result calculations.NOTE 6An automatic sample transfer and injection device may be used.10.3.1 Flush the sample loop with sufficient calibrant to assure that the material to be in

42、jected is representative.10.3.2 For LPG samples, if bubbles are present in the viewable portion of the liquid column, flush the sample loop to introducea new liquid-full sample portion.10.4 Start the analyzer and inject the calibration material according to the manufacturers instructions.10.5 Calibr

43、ate the instrument using one of the following techniques.TABLE 2 Typical Operating ConditionsSample inlet system temperature 85 20CSample injection system carrier gas 2530 mL/minFurnace temperature 1075 25CFurnace oxygen flow meter setting 375450 mL/minInlet oxygen flow meter setting 1030 mL/minInle

44、t carrier flow meter setting 130160 mL/minGas sample size 1020 mLLPG sample size 15 LTABLE 3 Typical Sulfur Calibration Ranges and StandardConcentrationsCurve ISulfur mg/kgCurve IISulfur mg/kgBlank Blank5.00 10.0010.00 50.00100.00TABLE 3 Typical Sulfur Calibration Ranges and StandardConcentrationsCu

45、rve ISulfur (mg/kg)Curve IISulfur (mg/kg)Curve IIISulfur (mg/kg)Blank Blank Blank5 10 5010 50 100100 200TABLE 4 Repeatability (r) and Reproducibility (R)Concentration(mg/kg S) rR1 0.1 0.35 0.6 1.610 1.2 3.125 2.9 7.850 5.8 15.6100 11.5 31.3TABLE 4 Repeatability (r) and Reproducibility (R)Concentrati

46、on Repeatability ReproducibilityS(mg/kg)GaseousHydrocarbons LPGGaseousHydrocarbons LPG1 0.1 0.3 0.3 2.35 0.6 0.8 1.6 7.225 2.9 2.6 7.8 2250 5.8 4.2 16 36100 12 6.8 31 58150 N/AA 9 N/A 77196 N/A 11 N/A 93A N ANot applicable to the scope of Gaseous Hydrocarbons.D6667 14510.5.1 Multi-point Calibration:

47、10.5.1.1 When the apparatus features an internal self-calibration routine, analyze the calibration standards and blank three timesusing the procedures described in 10.2 10.4.10.5.1.2 Calibrate the analyzer according to the manufacturers instructions to yield sulfur concentration (see Section 14). Th

48、iscurve is typically linear and system performance shall be checked at least once per day, each day of use. (Note 7).NOTE 7Other calibration curve techniques may be used when accuracy and precision are not degraded. The frequency of calibration may bedetermined by the use of quality control charts o

49、r other quality assurance/quality control techniques.10.5.2 One-point Calibration:10.5.2.1 Utilize a calibration standard (6.4) with a sulfur content close to that of the samples to be analyzed (625 % max.).10.5.2.2 Follow the instrument manufacturers instructions to establish an instrument zero (instrument blank) by conducting ananalysis run without injection of the calibration standard.10.5.2.3 Perform measurements of the calibration standard a minimum of three times.10.5.2.4 Calculate a calibration factor K, in counts per nan