1、Designation: D5705 15Standard Test Method forMeasurement of Hydrogen Sulfide in the Vapor PhaseAbove Residual Fuel Oils1This standard is issued under the fixed designation D5705; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the
2、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 field determination ofhydrogen sulfide (H2S) in the vapor phase (equilibrium head
3、-space) of a residual fuel oil sample.1.2 The test method is applicable to liquids with a viscosityrange of 5.5 mm2/s at 40C to 50 mm2/s at 100C. The testmethod is applicable to fuels conforming to Specification D396Grade Nos. 4, 5 (Heavy), and 6.1.3 The applicable range is from 5 mol mol to4000 mol
4、 mol (micromoles per mole) (5 ppm v v to4000 ppm v/v (parts per million by volume).1.4 The values stated in SI units are to be regarded asstandard. The values given in parentheses are for informationonly.1.5 This standard does not purport to address all of thesafety concerns, if any, associated with
5、 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:2D396 Specification for Fuel OilsD4057 Practice for Manual Sampling o
6、f Petroleum andPetroleum ProductsD6021 Test Method for Measurement of Total HydrogenSulfide in Residual Fuels by Multiple Headspace Extrac-tion and Sulfur Specific DetectionD7621 Test Method for Determination of Hydrogen Sulfidein Fuel Oils by Rapid Liquid Phase Extraction3. Terminology3.1 Definitio
7、ns:3.1.1 equilibrium headspace, nthe vapor space above theliquid in which all vapor components are in equilibrium withthe liquid components.3.1.2 residual fuel oil, na fuel oil comprising a blend ofviscous long, short, or cracked residue from a petroleumrefining process and lighter distillates blend
8、ed to a fuel oilviscosity specification.3.1.2.1 DiscussionUnder the conditions of this test (1:1liquid/vapor ratio, temperature, and agitation) the H2Sinthevapor phase (samples headspace) will be in equilibrium withthe H2S in the liquid phase.4. Summary of Test Method4.1 A 1 L H2S-inert test contain
9、er (glass test bottle) is filledto 50 % by volume with fuel oil from a filled H2S-inertcontainer (glass sample bottle) just prior to testing. In the testcontainer, the vapor space above the fuel oil sample is purgedwith nitrogen to displace air. The test container with sample isheated in an oven to
10、60 C, and agitated on an orbital shaker at3.67 s-16 0.08 s-1(220 r min 6 5 r min (revolutions perminute) for 3 min.4.2 A length-of-stain detector tube and hand-operated pumpare used to measure the H2S concentration in the vapor phaseof the test container. The length-of-stain detector tube shouldbe c
11、lose to but not in contact with the liquid surface.5. Significance and Use5.1 Residual fuel oils can contain H2S in the liquid phaseand this can result in hazardous vapor phase levels of H2Sinstorage tank headspaces. The vapor phase levels can varysignificantly according to the headspace volume, fue
12、l tempera-ture and agitation. Measurement of H2S levels in the liquidphase provides a useful indication of the residual fuel oilspropensity to form high vapor phase levels, and lower levels inthe residual fuel oil will directly reduce risk of H2S exposure.It is critical, however, that anyone involve
13、d in handling fuel oil,such as vessel owners and operators, continue to maintainappropriate safety practices designed to protect the crew, tankfarm operators and others who can be exposed to H2S.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products, Liquid Fuels, and
14、 Lubricants and is the direct responsibility ofSubcommittee D02.14 on Stability and Cleanliness of Liquid Fuels.Current edition approved April 1, 2015. Published July 2015. Originallyapproved in 1995. Last previous edition approved in 2014 as D5705 14. DOI:10.1520/D5705-15.2For referenced ASTM stand
15、ards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.*A Summary of Changes section appears at the end of this standardCopyright ASTM Interna
16、tional, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15.1.1 The measurement of H2S in the liquid phase isappropriate for product quality control, while the measurementof H2S in the vapor phase is appropriate for health and safetypurposes.5.2 This test method was
17、 developed to provide refineries,fuel terminals and independent testing laboratories, which donot have access to analytical instruments such as a gaschromatograph, with a simple and consistent field test methodfor the rapid determination of H2S in the vapor phase aboveresidual fuel oils.NOTE 1D5705
18、is one of three test methods for quantitativelymeasuring H2S in residual fuels:1) Test Method D6021 is an analytical test method to determine H2S levelsin the liquid phase.2) Test Method D7621 is a rapid test method to determine H2S levels inthe liquid phase.NOTE 2Because of the reactivity, absorpti
19、vity and volatility of H2S,any measurement method only provides an H2S concentration at a givenmoment in time.5.3 This test method does not necessarily simulate the vaporphase H2S concentration in a fuel storage tank. It does,however, provide a level of consistency so that the test result isonly a f
20、unction of the residual fuel oil sample and not the testmethod, operator, or location. No general correlation can beestablished between this field test and actual vapor phaseconcentrations of H2S in residual fuel oil storage or transports.However, a facility that produces fuel oil from the same crud
21、esource under essentially constant conditions might be able todevelop a correlation for its individual case.6. Interferences6.1 Typically, sulfur dioxide and mercaptans may causepositive interferences. In some cases, nitrogen dioxide cancause a negative interference. Most detector tubes will have ap
22、recleanse layer designed to remove certain interferences up tosome maximum interferant level. Consult the manufacturersinstructions for specific interference information.7. Apparatus7.1 Shaker, a bench-top orbital shaker and platformequipped with a four-prong clamp to hold 1 L Boston round-bottom gl
23、ass bottles and capable of operation at 3.67 s-160.08 s-1(220 r min 6 5 r min (revolutions per minute).NOTE 3An orbital shaker with an orbit of 19 mm has been found tobe suitable.7.2 Timer, capable of measuring from 1 s to 30 min atsecond intervals.7.3 Stopper with Temperature Measuring Device, a No
24、. 2cork stopper with a temperature measuring devices insertedthrough it that is capable of accurately measuring the tempera-ture of the sample at 60 C 6 1 C as required in the procedureand extending at least 25 mm into the residual fuel but nocloser than 25 mm from the bottom of a test bottle (see F
25、ig.1(a). A dial thermometer having a range of 18 C to 82 Cand a 200 mm stem has been found suitable to use.7.4 Oven or Water Bath, capable of heating the fuel oilsamples to 60 C 6 1 C.7.5 Detector Tube Pump, a hand-operated piston or bellows-type (Fig. 1(b) pump with a capacity of 100 cm36 5cm3perst
26、roke.3It must be specifically designed for use with detectortubes. (WarningA detector tube and pump together form aunit and must be used as such. Each manufacturer calibratesdetector tubes to match the flow characteristics of its specificpump. Crossing brands of pumps and tubes is not permitted, asc
27、onsiderable loss of system accuracy is likely to occur.)8. Reagents and Materials8.1 ContainersBoth sample and test containers are com-posed of H2S-inert material such as 1 L size (clear Bostonround-bottom) glass bottles with screw caps. The bottles areclean and dry. Mark test containers at the 50 %
28、 volume level byusing a ruler. (WarningHydrogen sulfide reacts with metalsurfaces and is easily oxidized, which depletes its concentra-tion and gives false low test results. Containers such asepoxy-lacquered cans are suitable for sample collection. Alter-native containers must give equivalent result
29、s to those obtainedby using glass.)3Direct Reading Colorimetric Indicator Tubes Manual, First Edition, AmericanIndustrial Hygiene Association, Akron, OH 44311, 1976.FIG. 1 Measurement of H2S in the Vapor Phase of Residual FuelOilD5705 1528.2 Length-of-Stain Detector Tube and Calibration Scale, aseal
30、ed glass tube with breakoff tips sized to fit the tube holderof the detector tube pump. The reagent layer inside the tube,typically a silica gel substrate coated with the active chemicals,must be specific for hydrogen sulfide and must produce adistinct color change when exposed to a sample of gascon
31、taining hydrogen sulfide. Any substances known to inter-fere must be listed in the instructions accompanying the tubes.A calibration scale should be marked directly on the tube, orother markings that provide for easy interpretation (reading) ofhydrogen sulfide content from a separate calibration sca
32、leshould be supplied with the tubes. The calibration scale shallcorrelate H2S concentration to the length of the color stain.Annex A1 provides additional information. Shelf life of thedetector tubes must be a minimum of two years from the dateof manufacture, when stored according to the manufacturer
33、srecommendations.9. Sampling9.1 The sampling of residual fuel oils is done according toPractice D4057 for the sampling of storage tanks, ships, orbarges. Composite sampling or running samples can be taken;spot samples should be taken from the midpoint or belowmidpoint of the fuel oil in a storage ta
34、nk by first sufficientlypurging sample transfer lines and then taking single sampleswhere each sample comprises one and only one test.(WarningSamples taken for this test method shall be dedi-cated to a single H2S determination and not used for any otherpurpose, as any additional handling can lead to
35、 loss of H2S andthus low results.)NOTE 4Liquid samples taken well into the fuel oil have had less H2Slost by degassing as compared with a fuel oils surface. Samples takenfrom well within the fuel oil storage provide material that represents thegreatest potential for H2S exposure during fuel oil move
36、ments. Hydrogensulfide is lost by degassing (elevated temperature and mechanical agitationincreases H2S degassing), oxidation, and absorption on water-wet sur-faces.9.2 Fill at least two 1 L size sample containers with fuel oil.Minimize the headspace of the sample container. Cap imme-diately and del
37、iver to the testing facility. Test each samplewithin one to four hours from the time of sampling.9.3 Sample integrity is extremely important; therefore,sample containers must be composed of inert materials, fillednearly completely with liquid, and capped tightly until tested.Sample handling should b
38、e minimized, and rapid testing forH2S is required. Samples can not be stored for later testing asH2S loss may occur by the mechanism described in Note 4.10. Procedure10.1 Let each filled sample container sit at room tempera-ture for at least 1 h, transfer part of its contents to an empty 1 Ltest bot
39、tle such that it is filled 50 % 6 5 volume % with thesample. Discard the remaining contents of the sample containerin compliance with applicable laws. A single test is to beperformed on material from an individual sample container.10.2 Insert a nitrogen purge line outlet to within about13 mm above t
40、he fuel surface. Nitrogen purge at 2 L min for30 s the headspace above the test sample to displace air andwater vapor. Minimize the time the bottle is open to avoidfurther loss of sample vapors. Close the test bottle opening (gastight) with a cork stopper fitted with a dial thermometer (Fig.1(a) imm
41、ediately after nitrogen purging.10.3 Place each test bottle with sample in an oven or a waterbath, set at 60 C 6 1 C, until the sample temperature reaches60 C 6 1 C. Keep the sample in the oven or bath for aminimum of 30 min, which includes the time for the sample toreach 60 C.NOTE 5If the sample te
42、mperature does not reach 60 C, low resultswill be obtained for the H2S concentration. If the temperature exceeds60 C, high results will be obtained for the H2S concentration.10.4 While the sample is heating, place an unbroken length-of-stain detector tube in the hand-operated pump and test thepump f
43、or leaks. Consult the manufacturers instructions forleak check procedure details and for maintenance instructionsif leaks are detected. The leak check typically takes 1 min.10.5 Remove the test bottle from the oven and place it in thefour-prong clamp of the shaker. Shake at 3.67 s-16 0.08 s-1(220 r
44、min 6 5 r min (revolutions per minute) for 3 min 61 s to achieve H2S equilibrium between the liquid and thevapor phase.10.6 Rest the test bottle on a flat surface, remove the stopperwith the dial thermometer, and immediately seal the top of thebottle with aluminum foil.10.7 Select a detector tube wi
45、th a range that best encom-passes the expected H2S concentration. Reading accuracy isimproved when the stain length extends into the upper half ofthe calibration scale.10.8 Break off the tube tips and insert the tube into thepump, observing the flow direction indication on the tube.Insert the tube t
46、hrough the aluminum foil on the test bottle.Rest the pump on top of the test bottle with the detector tubeonly contacting the samples vapor phase. Do not allow thedetector tube to contact the liquid, see Fig. 1(b). Use one fullcompression stroke.10.9 Remove the detector tube after complete decompres
47、-sion of the pump and immediately read the H2S concentrationfrom the tubes calibration scale or from the charts provided inthe box of tubes. Read the tube at the maximum point of thestain. If channeling has occurred (non-uniform stain length),read the maximum and minimum stain lengths and average th
48、etwo readings. (WarningIf the calibration scale is not printeddirectly on the detector tube, be certain that any separatecalibration chart is the proper match for the tube in use to avoidincorrect results.)10.10 If the calibration scale specifies more than one stroke,correct the reading as below:Cco
49、r5 C 3S (1)where:Ccor= the corrected hydrogen sulfide concentration in mi-cromoles per mole (ppm v/v),C = the reading from the detector tube in micromoles permole (ppm v/v), andD5705 153S = the specified number of strokes.NOTE 6If the test is being conducted at an altitude above 610 m,corrections for barometric pressure are significant. In this case, correct thereading as below:Ccor5 C 3101.325P (2)where:Ccor= the corrected hydrogen sulfide concentration in micromoles permole (ppm v/v),C = the reading from the detector tub
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