1、Designation: D4045 15Standard Test Method forSulfur in Petroleum Products by Hydrogenolysis andRateometric Colorimetry1This standard is issued under the fixed designation D4045; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the y
2、ear 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 sulfur inpetroleum products in the range from 0.02 mg kg to10.00
3、mg kg.1.2 This test method may be extended to higher concentra-tion by dilution.1.3 This test method is applicable to liquids whose boilingpoints are between 30 C and 371 C (86 F and 700 F).Materials that can be analyzed include naphtha, kerosine,alcohol, steam condensate, various distillates, jet f
4、uel, benzene,and toluene.1.4 The values stated in SI units are to be regarded asstandard. The values given in parentheses are for informationonly.1.4.1 Certain specifications for the recorder (see 5.5) areexcepted.1.5 This standard does not purport to address all of thesafety concerns, if any, assoc
5、iated 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:2D1193 Specification for Reagent WaterD6299 Practice for Ap
6、plying Statistical Quality Assuranceand Control Charting Techniques to Evaluate AnalyticalMeasurement System Performance3. Summary of Test Method3.1 The sample is injected at a constant rate into a flowinghydrogen stream in a hydrogenolysis apparatus. The sampleand hydrogen are pyrolyzed at a temper
7、ature of 1300 C, orabove, to convert sulfur compounds to hydrogen sulfide (H2S).Readout is by the rateometric detection of the colorimetricreaction of H2S with lead acetate. Condensable components areconverted to gaseous products, such as methane, during hy-drogenolysis.4. Significance and Use4.1 In
8、 many petroleum refining processes, low levels ofsulfur in feed stocks may poison expensive catalysts. This testmethod can be used to monitor the amount of sulfur in suchpetroleum fractions.4.2 This test method may also be used as a quality-controltool for sulfur determination in finished products.5
9、. Apparatus3,45.1 Pyrolysis FurnaceA furnace that can provide anadjustable temperature from 900 C to 1400 C in a 5 mminside diameter or larger tube is required to pyrolyze thesample. The furnace entry temperature shall allow insertion ofthe hypodermic tip to a depth at which the temperature is550 C
10、to provide sample vaporization at the injection syringetip. This temperature shall be above the boiling point of thesample and of the sulfur compounds in the sample (see Fig. 1).The pyrolyzer tube may be of quartz; however, the lifetime islimited above 1250 C. Ceramic may be used at any tempera-ture
11、.5.2 Rateometric H2S ReadoutHydrogenolysis productscontain H2S in proportion to sulfur in the sample. The H2Sismeasured by measuring rate of change of reflectance caused bydarkening when lead sulfide is formed. Rateometricelectronics, adapted to provide a first derivative output, allowssufficient se
12、nsitivity to measure below 0.1 mg/L (see Fig. 2).1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products, Liquid Fuels, and Lubricantsand is the direct responsibility ofSubcommittee D02.03 on Elemental Analysis.Current edition approved April 1, 2015. Published April 20
13、15. Originallyapproved in 1987. Last previous edition approved in 2010 as D4045 04 (2010).DOI: 10.1520/D4045-15.2For 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
14、standards Document Summary page onthe ASTM website.3The apparatus described in 5.1 5.4 inclusive is similar in specification to theequipment available from Analytical Systems Keco, 9215 Solon Rd., Suite A4,Houston, TX 77064. For further information see Drushel, H. V., “Trace SulfurDetermination Petr
15、oleum Fractions,” Analytical Chemistry, Vol 50, 1978, p. 76.4The sole source of supply of the apparatus known to the committee at this timeisAnalytical Systems Keco. If you are aware of alternative suppliers, please providethis information to ASTM International Headquarters. Your comments will recei
16、vecareful consideration at a meeting of the responsible technical committee,1whichyou may attend.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15.3 Hypodermic SyringeA
17、hypodermic having a needlelong enough to reach the 550 C zone is required. A side portis convenient for vacuum filling and for flushing the syringe. A100 L syringe is satisfactory for injection rates down to3 L min and a 25 L syringe for lower rates. (WarningExercise caution as hypodermics can cause
18、 accidental injury.)5.4 Syringe Injection DriveThe drive shall provideuniform, continuous sample injections. Variation in driveinjection rate caused by mechanical irregularities of gears willcause noise. The adjustable drive shall be capable of injectionfrom 6 L min to 0.06 L min over a 6 min interv
19、al.5.5 RecorderA chart recorder with 10 V full scale and10 000- input or greater and having a chart speed of0.2 in. min to 1 in. min (approximately 0.5 cm/min to 3 cm-min) is required. An attenuator can be used for more sensitiverecorders. Newer instruments that display the results areacceptable in
20、lieu of a chart recorder.5.6 ThermocoupleA thermocouple suitable for use at500 C to 1400 C, 250 mm long with readout is required.Type K,116 in. (1.6 mm) diameter, Type 316 stainless steelsheath is suitable.6. Reagents and Materials6.1 Purity of ReagentsReagent grade chemicals shall beused in all tes
21、ts. Unless otherwise indicated, it is intended thatall reagents conform to the specifications of the Committee onAnalytical Reagents of the American Chemical Society wheresuch specifications are available.5Other grades may be used,provided it is first ascertained that the reagent is of sufficientlyh
22、igh purity to permit its use without lessening the accuracy ofthe determination.6.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean Type II reagent gradewater conforming to Specification D1193.6.3 Sensing TapeLead acetate impregnated paper of chro-matographi
23、c quality shall be used. (WarningLead is acumulative poison.)6.4 HydrogenAs no commercial grade of hydrogen has asulfur specification sufficiently low, each new source of supplymust be tested. A change in the zero base line of 5 % of fullscale from no flow to full flow indicates impure hydrogen.(War
24、ningExtremely flammable gas under pressure. Hydro-gen is a flammable gas. Test all flow systems for leaks and5Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For Suggestions on the testing of reagents notlisted by the American Chemical Society,
25、see Annual Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.NOTE 1The humidifier gas wash bottle is optional.FIG. 1 Hydrogenolysis Flow DiagramFIG. 2 Photorateometry H2
26、S ReadoutD4045 152purge with inert gas before introducing hydrogen and afterremoving hydrogen. Keep all flow systems as small in volumeas practical and provide protective screening for containersother than sample flow lines. Dispose of exhaust gases in afume hood or by vacuuming to a safe area. If g
27、as cylinders areused handle carefully as rupture of the valve or cylinder isdangerous.)6.5 Reference Standards:6.5.1 2,2,4 Trimethyl Pentane (Isooctane)(WarningExtremely flammable.)6.5.1.1 ASTM Knock Test Reference Fuel6may be used asthe solvent. However, when this material is used, each new lotshal
28、l be tested for sulfur by this procedure because thespecifications are not rigorous enough for this application.NOTE 1Heptane or equivalent material may also be used but precisiondata is based on the use of isooctane.6.6 Acetic Acid SolutionMix glacial acetic acid 1 part byvolume into 19 parts water
29、 (see 6.2). (WarningCorrosive.)6.7 Di-n-Butyl Sulfide(CH3CH2CH2CH2)2S) is used toprepare standards. Equivalent sulfur compound may be used ifcare is exercised to prevent more volatile compounds fromevaporating during preparation or use of standards.6.8 Helium or Nitrogen Purge Gas. (WarningCompresse
30、d gas under high pressure.)7. Preparation of Apparatus7.1 Turn on the furnace with temperature controls at mini-mum. Gradually increase furnace control over a 3 h period toapproximately 1300 C to minimize thermal shock. Reversethe procedure when preparing for long-term storage. Forshutdown at night
31、and over weekends, reduce temperature toabout 900 C but do not turn off the furnace. Furnace andquartz tubing life are extended by not cooling to roomtemperature.7.2 Connect all tubing and fill prehumidifier outside thecabinet with water if this apparatus is being used, and finalhumidifier inside th
32、e cabinet with 5 % by volume acetic acidsolution. Purge with inert gas, then close valve. Check allconnections and repair any leaks that are found.(WarningOn instruments where electronics are in closeproximity with the flow systems, exercise care if leak checkingwith a soap solution. A suitable meth
33、od is to block the line thatgoes to the final humidifier and observe the flow meter. If theflow drops to zero, the flow systems are adequately leak-free.)Set hydrogen flow at 200 mL min, and allow temperature tostabilize. (WarningExtremely flammable gas under pres-sure.) Make final temperature adjus
34、tment to 1315 C 6 15 C.Use a standard thermocouple to verify temperature by insertingthrough a septum with hydrogen flowing at the rate notedabove. Determine depth of insertion required, and always insertthe hypodermic tip to the 550 C point (see7.6).(WarningThe use of a humidifier gas wash bottle f
35、illedwith approximately 250 mL of water is a potential safetyhazard as hydrogen pressure may build up inside the container.The user of this test method should take appropriate safetymeasures to prevent an accidental injury, if the humidifier gaswash bottle is used in the analysis.)7.3 Prepare the sa
36、mple injection drive. Check to be suredesired injection rate is obtained at various settings. Verify thaterratic pulses of fast drive do not occur when the drive rangeis switched. Pulses of high sample flow above 15 L min willcause carboning and spurious readings.7.4 Install sensing tape, and turn H
37、2S readout analyzer on.7.5 Connect the recorder and adjust the zero to desiredposition with hydrogen flowing.7.6 Fill syringe with blank reference standard solution,typically isooctane, insert the needle through the septum to the550 C temperature zone, and clamp to the syringe drive. Athigh temperat
38、ure the hot needle may absorb sulfur and at lowertemperature heavy compounds may not evaporate. Set thesyringe drive rate desired, normally 6 L min, maximum with200 mL min hydrogen flow. Drive rate may be increased forincreased sensitivity up to the point at which carbon is formed.(Hydrogen flow at
39、500 mL min allows injection of 15 L min;however, dibenzothiophene conversion will be low.)8. Calibration Standard8.1 Prepare a reference standard-solution or solutions ofstrength near that expected in the unknown. Measurements canbe made by weight or by volume for carrier liquid.8.2 Units of sulfur
40、in milligrams per litre of sample arepreferred as this is independent of the density of the carrierliquid. The following equation is used to calculate the volumeof solvent required to dissolve a precise weight of sulfurcompound, of known composition and purity to prepare aliquid standard:z 5Sbc3 d 3
41、 e 3106D/a! or alternatively: (1)a 5Sbc3 d 3 e 3106D/z! (2)where:a = desired concentration of sulfur, mg/L, of the standardsolution of z millilitre of volume,b = molecular weight of sulfur: 32.06,c = molecular weight of the sulfur compound to be used toprepare the standard.d = mass of the sulfur com
42、pound used to prepare thestandard, g,e = purity of sulfur compound expressed as a decimal, andz = millilitres of standard solution required to give thedesired concentration a.Example:Calculate the volume of sulfur free isooctane with volume ofsulfur compound necessary to dissolve 0.5013 g of 98 % by
43、weight di-n-butyl sulfide to obtain a standard containing 1000mg/L of sulfur in a solution.a = 1000 mg/Lb = 32.06c = 146.29 di-n-butyl sulfide (CH3CH2CH2CH2)2S6Available from Phillips Petroleum Co., P.O. Drawer O, Borger, TX 79071.D4045 153d = 0.5013 ge = 0.98z =32.06 / 146.29#30.501330.983106100051
44、07.66 mLIsooctane is added to bring the solution to a total volume of107.66 mL. When results are to be reported in mass of parts permillion mg/kg, the conversion from milligrams per litre shouldbe done as the last step in the calculations.8.3 To prepare a sulfur standard with a sulfur concentrationo
45、f 1000 mg L, as previously described, obtain a clean 125 mLglass container, a 100 mL flask, and a 20 mL graduated glasspipet. Rinse each thoroughly with 2,2,4-trimethyl pentane(isooctane). (WarningExtremely flammable.) Pour approxi-mately 90 mL of isooctane into the 100 mL flask. Weighapproximately
46、0.5 g of di- n-butyl sulfide directly into the flaskand record the mass added, to 650 g. Add additional isooc-tane to the flask to 100 mL. Transfer the mixture to the 125 mLcontainer and add isooctane equal to the difference of z minus100 mL. Keep containers closed as much as possible. Do notopen co
47、ntainers of pure sulfur compound in the vicinity ofsulfur free stocks or low-level standards. Evaporation fromcontainers of pure sulfur compounds can contaminate othernearby liquids. This is particularly troublesome when workingbelow 1 mg/L near volatile sulfur compounds. Volumetricallydilute stock
48、to prepare low-level standards.9. Calibration and Standardization9.1 With hydrogen flow at 200 mL min, advance new tapeand note baseline. Adjust the offset up scale about 5 % to beclear of the recorder stops. Record the stable reading averagevalue as the zero sulfur reference and record as Rbin 11.1
49、.There will be essentially no difference in reading with orwithout hydrogen flow and with or without blank injection, ifblank and hydrogen have no sulfur.9.2 Advance the tape and inject a reference material with asulfur concentration near that expected in the unknown. Afterabout 4 min injection time, adjust the recorder span forapproximately 90 % of scale. Record the average reading asRstdin 10.1.10. Procedure10.1 Advance the tape and inject the unknown sample.Aftera stable reading is obtained record this a
