1、Designation: D5705 13Standard 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 to 4000 parts per
4、millionby volume (ppm v/v) (micro mole/mole).1.4 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 o
5、f 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 of Petroleum andPetroleum ProductsD6
6、021 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 Definitions:3.1.1 equilibrium headspace, nth
7、e 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 blended to a fuel oilviscosity specifica
8、tion.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 container (glass test bottle) is filledto
9、50 volume % with fuel oil from a filled H2S-inert container(glass sample bottle) just prior to testing. In the test container,the vapor space above the fuel oil sample is purged withnitrogen to displace air. The test container with sample isheated in an oven to 60C, and agitated on an orbital shaker
10、 at220 rpm 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 close to but not in contact with the liquid surface.5. Significance and Use5.1 Residual fuel oi
11、ls 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, fuel tempera-ture and agitation. Measurement of H2S levels in the liquidphase provides a useful i
12、ndication 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 involved in handling fuel oil,such as vessel owners and operators, continue to maintainappropriate sa
13、fety practices designed to protect the crew, tankfarm operators and others who can be exposed to H2S.5.1.1 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.1This test meth
14、od is under the jurisdiction of ASTM Committee D02 onPetroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility ofSubcommittee D02.14 on Stability and Cleanliness of Liquid Fuels.Current edition approved Dec. 1, 2013. Published December 2013. Originallyapproved in 1995. Last p
15、revious edition approved in 2012 as D5705 12. DOI:10.1520/D5705-12.2For 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 standards Document Summary page onthe ASTM we
16、bsite.*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 States15.2 This test method was developed to provide refineries,fuel terminals and independent testing laboratories, which
17、 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 is one of three test methods for quantitativelymeasuring H2S in residual fuels:1) Test Meth
18、od 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, absorptivity and volatility of H2S,any measurement method only provides an H2S concentration at a g
19、ivenmoment 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 function of the residual fuel oil sample and not the testmethod, operator, or location. No g
20、eneral 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 crudesource under essentially constant conditions might be able todevelop a correlation for its
21、 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 aprecleanse layer designed to remove certain interferences up tosome maximum interferant leve
22、l. 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 glass bottles and capable of operation at 220 rpm.NOTE 3An orbital shaker with an orbit of 19
23、 mm has been found tobe suitable.7.2 Timer, capable of measuring from1sto30minatsecond intervals.7.3 Stopper with Temperature Measuring Device, a No. 2cork stopper with a temperature measuring devices insertedthrough it that is capable of accurately measuring the tempera-ture of the sample at 60 6 1
24、C as required in the procedure andextending at least 25 mm into the residual fuel but no closerthan 25 mm from the bottom of a test bottle (see Fig. 1(a). Adial thermometer having a range of 18 to 82C and a 200mmstem has been found suitable to use.7.4 Oven or Water Bath, capable of heating the fuel
25、oilsamples to 60 6 1C.7.5 Detector Tube Pump, a hand-operated piston or bellows-type (Fig. 1(b) pump with a capacity of 100 cm36 5cm3perstroke.3It must be specifically designed for use with detectortubes. (WarningA detector tube and pump together form aunit and must be used as such. Each manufacture
26、r calibratesdetector tubes to match the flow characteristics of its specificpump. Crossing brands of pumps and tubes is not permitted, asconsiderable 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
27、 such as 1-L size (clear Bostonround-bottom) glass bottles with screw caps. The bottles areclean and dry. Mark test containers at the 50 % volume level byusing a ruler. (WarningHydrogen sulfide reacts with metalsurfaces and is easily oxidized, which depletes its concentra-tion and gives false low te
28、st results. Containers such asepoxy-lacquered cans are suitable for sample collection. Alter-native containers must give equivalent results to those obtainedby using glass.)3Direct Reading Colorimetric Indicator Tubes Manual, First Edition, AmericanIndustrial Hygiene Association, Akron, OH 44311, 19
29、76.FIG. 1 Measurement of H2S in the Vapor Phase of Residual FuelOilD5705 1328.2 Length-of-Stain Detector Tube and Calibration Scale, asealed 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
30、with the active chemicals,must be specific for hydrogen sulfide and must produce adistinct color change when exposed to a sample of gascontaining hydrogen sulfide. Any substances known to inter-fere must be listed in the instructions accompanying the tubes.A calibration scale should be marked direct
31、ly on the tube, orother markings that provide for easy interpretation (reading) ofhydrogen sulfide content from a separate calibration scaleshould be supplied with the tubes. The calibration scale shallcorrelate H2S concentration to the length of the color stain.Annex A1 provides additional informat
32、ion. Shelf life of thedetector tubes must be a minimum of two years from the dateof manufacture, when stored according to the manufacturersrecommendations.9. Sampling9.1 The sampling of residual fuel oils is done according toPractice D4057 for the sampling of storage tanks, ships, orbarges. Composit
33、e sampling or running samples can be taken;spot samples should be taken from the midpoint or belowmidpoint of the fuel oil in a storage tank by first sufficientlypurging sample transfer lines and then taking single sampleswhere each sample comprises one and only one test.(WarningSamples taken for th
34、is test method shall be dedi-cated to a single H2S determination and not used for any otherpurpose, as any additional handling can lead to 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. Sampl
35、es takenfrom well within the fuel oil storage provide material that represents thegreatest potential for H2S exposure during fuel oil movements. Hydrogensulfide is lost by degassing (elevated temperature and mechanical agitationincreases H2S degassing), oxidation, and absorption on water-wet sur-fac
36、es.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 deliver 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 con
37、tainers must be composed of inert materials, fillednearly completely with liquid, and capped tightly until tested.Sample handling should be 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. Proce
38、dure10.1 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 bottle 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 te
39、st is to beperformed on material from an individual sample container.10.2 Insert a nitrogen purge line outlet to within about 13mm above the fuel surface. Nitrogen purge at 2 L/min for 30 sthe headspace above the test sample to displace air and watervapor. Minimize the time the bottle is open to avo
40、id further lossof sample vapors. Close the test bottle opening (gas tight) witha cork stopper fitted with a dial thermometer (Fig. 1(a)immediately after nitrogen purging.10.3 Place each test bottle with sample in an oven or a waterbath, set at 60 6 1C, until the sample temperature reaches 606 1C. Ke
41、ep the sample in the oven or bath for a minimum of30 min, which includes the time for the sample to reach 60C.NOTE 5If the sample temperature does not reach 60C, low resultswill be obtained for the H2S concentration. If the temperature exceeds60C, high results will be obtained for the H2S concentrat
42、ion.10.4 While the sample is heating, place an unbroken length-of-stain detector tube in the hand-operated pump and test thepump for leaks. Consult the manufacturers instructions forleak check procedure details and for maintenance instructionsif leaks are detected. The leak check typically takes 1 m
43、in.10.5 Remove the test bottle from the oven and place it in thefour-prong clamp of the shaker. Shake at 220 rpm for 3 min 61sto 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 sea
44、l the top of thebottle with aluminum foil.10.7 Select a detector tube with 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 thepum
45、p, observing the flow direction indication on the tube.Insert the tube through 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 fullc
46、ompression stroke.10.9 Remove the detector tube after complete decompres-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
47、 stain length),read the maximum and minimum stain lengths and average thetwo 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 calibrati
48、on scale specifies more than one stroke,correct the reading as below:ppm v/v corrected! 5 ppm v/v reading! 3specified strokes (1)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:ppm v/v corr
49、ected! 5 ppm v/v reading! (2)3101.325 kPa!/barometric pressure, kPa!10.11 If the detector tube reading is over- or under-ranged,take another detector tube of a different range and test a secondD5705 133sample of the fuel oil. Do not repeat testing on a previouslytested sample or reuse detector tubes. Continue the testingusing different ranged detector tubes and new samples untileither the reading is on-scale or less than 5 ppm v/v.10.12 After obtaining a satisfactory first result, repeat thetest with another sample of the same fuel oil a
