1、Designation: D5705 13D5705 14Standard 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 revisi
2、on, 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 field determination of hydrogen sulfide (H2S) in the vapor phase (equilib
3、rium headspace) of aresidual fuel oil sample.1.2 The test method is applicable to liquids with a viscosity range of 5.5 mm2/s at 40C to 50 mm2 /s at 100C. The test methodis applicable to fuels conforming to Specification D396 Grade Nos. 4, 5 (Heavy), and 6.1.3 The applicable range is from 5 to 4000
4、parts per million by volume (ppm v/v) (micro mole/mole).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 r
5、esponsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D396 Specification for Fuel OilsD4057 Practice for Manual Sampling of Petroleum and Petroleu
6、m ProductsD6021 Test Method for Measurement of Total Hydrogen Sulfide in Residual Fuels by Multiple Headspace Extraction and SulfurSpecific DetectionD7621 Test Method for Determination of Hydrogen Sulfide in Fuel Oils by Rapid Liquid Phase Extraction3. Terminology3.1 Definitions:3.1.1 equilibrium he
7、adspace, nthe vapor space above the liquid in which all vapor components are in equilibrium with theliquid components.3.1.2 residual fuel oil, na fuel oil comprising a blend of viscous long, short, or cracked residue from a petroleum refiningprocess and lighter distillates blended to a fuel oil visc
8、osity specification.3.1.2.1 DiscussionUnder the conditions of this test (1:1 liquid/vapor ratio, temperature, and agitation) the H2S in the vapor phase (samplesheadspace) will be in equilibrium with the H2S in the liquid phase.4. Summary of Test Method4.1 A1-LH2S-inert test container (glass test bot
9、tle) is filled to 50 volume % with fuel oil from a filled H2S-inert container (glasssample bottle) just prior to testing. In the test container, the vapor space above the fuel oil sample is purged with nitrogen todisplace air. The test container with sample is heated in an oven to 60C, and agitated
10、on an orbital shaker at 220 rpm for 3 min.1 This test method is under the jurisdiction ofASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of SubcommitteeD02.14 on Stability and Cleanliness of Liquid Fuels.Current edition approved Dec. 1, 2013Jun
11、e 1, 2014. Published December 2013July 2014. Originally approved in 1995. Last previous edition approved in 20122013 asD5705 12.D5705 13. DOI: 10.1520/D5705-12.10.1520/D5705-14.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. Fo
12、r 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 standard an indication of what changes have been made to the previous version. Becauseit may n
13、ot 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 by ASTM is to be considered the official document.*A Summary of Changes section appears at the e
14、nd of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States14.2 A length-of-stain detector tube and hand-operated pump are used to measure the H2S concentration in the vapor phase ofthe test container. The length-of-stain detec
15、tor tube should be close to but not in contact with the liquid surface.5. Significance and Use5.1 Residual fuel oils can contain H2S in the liquid phase and this can result in hazardous vapor phase levels of H2S in storagetank headspaces. The vapor phase levels can vary significantly according to th
16、e headspace volume, fuel temperature and agitation.Measurement of H2S levels in the liquid phase provides a useful indication of the residual fuel oils propensity to form high vaporphase levels, and lower levels in the residual fuel oil will directly reduce risk of H2S exposure. It is critical, howe
17、ver, that anyoneinvolved in handling fuel oil, such as vessel owners and operators, continue to maintain appropriate safety practices designed toprotect the crew, tank farm operators and others who can be exposed to H2S.5.1.1 The measurement of H2S in the liquid phase is appropriate for product qual
18、ity control, while the measurement of H2S inthe vapor phase is appropriate for health and safety purposes.5.2 This test method was developed to provide refineries, fuel terminals and independent testing laboratories, which do not haveaccess to analytical instruments such as a gas chromatograph, with
19、 a simple and consistent field test method for the rapiddetermination of H2S in the vapor phase above residual fuel oils.NOTE 1D5705 is one of three test methods for quantitatively measuring H2S in residual fuels:1) Test Method D6021 is an analytical test method to determine H2S levels in the liquid
20、 phase.2) Test Method D7621 is a rapid test method to determine H2S levels in the liquid phase.NOTE 2Because of the reactivity, absorptivity and volatility of H2S, any measurement method only provides an H2S concentration at a given momentin time.5.3 This test method does not necessarily simulate th
21、e vapor phase H2S concentration in a fuel storage tank. It does, however,provide a level of consistency so that the test result is only a function of the residual fuel oil sample and not the test method,operator, or location. No general correlation can be established between this field test and actu
22、al vapor phase concentrations of H2Sin residual fuel oil storage or transports. However, a facility that produces fuel oil from the same crude source under essentiallyconstant conditions might be able to develop a correlation for its individual case.6. Interferences6.1 Typically, sulfur dioxide and
23、mercaptans may cause positive interferences. In some cases, nitrogen dioxide can cause anegative interference. Most detector tubes will have a precleanse layer designed to remove certain interferences up to somemaximum interferant level. Consult the manufacturers instructions for specific interferen
24、ce information.7. Apparatus7.1 Shaker, a bench-top orbital shaker and platform equipped with a four-prong clamp to hold 1-L Boston round-bottom glassbottles and capable of operation at 220 rpm.NOTE 3An orbital shaker with an orbit of 19 mm has been found to be suitable.7.2 Timer, capable of measurin
25、g from 1 s to 30 min at second intervals.7.3 Stopper with Temperature Measuring Device, a No. 2 cork stopper with a temperature measuring devices inserted throughit that is capable of accurately measuring the temperature of the sample at 60 6 1C as required in the procedure and extendingat least 25
26、mm into the residual fuel but no closer than 25 mm from the bottom of a test bottle (see Fig. 1(a). A dial thermometerhaving a range of 18 to 82C and a 200mm stem has been found suitable to use.7.4 Oven or Water Bath, capable of heating the fuel oil samples to 60 6 1C.7.5 Detector Tube Pump, a hand-
27、operated piston or bellows-type (Fig. 1(b) pump with a capacity of 100 cm3 6 5 cm3 perstroke.3 It must be specifically designed for use with detector tubes. (WarningA detector tube and pump together form a unitand must be used as such. Each manufacturer calibrates detector tubes to match the flow ch
28、aracteristics of its specific pump.Crossing brands of pumps and tubes is not permitted, as considerable loss of system accuracy is likely to occur.)8. Reagents and Materials8.1 ContainersBoth sample and test containers are composed of H2S-inert material such as 1-L size (clear Bostonround-bottom) gl
29、ass bottles with screw caps. The bottles are clean and dry. Mark test containers at the 50 % volume level by usinga ruler. (WarningHydrogen sulfide reacts with metal surfaces and is easily oxidized, which depletes its concentration and givesfalse low test results. Containers such as epoxy-lacquered
30、cans are suitable for sample collection.Alternative containers must giveequivalent results to those obtained by using glass.)3 Direct Reading Colorimetric Indicator Tubes Manual, First Edition, American Industrial Hygiene Association, Akron, OH 44311, 1976.D5705 1428.2 Length-of-Stain Detector Tube
31、and Calibration Scale, a sealed glass tube with breakoff tips sized to fit the tube holder ofthe detector tube pump. The reagent layer inside the tube, typically a silica gel substrate coated with the active chemicals, mustbe specific for hydrogen sulfide and must produce a distinct color change whe
32、n exposed to a sample of gas containing hydrogensulfide. Any substances known to interfere must be listed in the instructions accompanying the tubes. A calibration scale shouldbe marked directly on the tube, or other markings that provide for easy interpretation (reading) of hydrogen sulfide content
33、 froma separate calibration scale should be supplied with the tubes. The calibration scale shall correlate H2S concentration to the lengthof the color stain. AnnexA1 provides additional information. Shelf life of the detector tubes must be a minimum of two years fromthe date of manufacture, when sto
34、red according to the manufacturers recommendations.9. Sampling9.1 The sampling of residual fuel oils is done according to Practice D4057 for the sampling of storage tanks, ships, or barges.Composite sampling or running samples can be taken; spot samples should be taken from the midpoint or below mid
35、point of thefuel oil in a storage tank by first sufficiently purging sample transfer lines and then taking single samples where each samplecomprises one and only one test. (WarningSamples taken for this test method shall be dedicated to a single H2S determinationand not used for any other purpose, a
36、s any additional handling can lead to loss of H2S and thus low results.)NOTE 4Liquid samples taken well into the fuel oil have had less H2S lost by degassing as compared with a fuel oils surface. Samples taken fromwell within the fuel oil storage provide material that represents the greatest potenti
37、al for H2S exposure during fuel oil movements. Hydrogen sulfide islost by degassing (elevated temperature and mechanical agitation increases H2S degassing), oxidation, and absorption on water-wet surfaces.9.2 Fill at least two 1-L size sample containers with fuel oil. Minimize the headspace of the s
38、ample container. Cap immediatelyand deliver to the testing facility. Test each sample within 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, filled nearlycompletely with liquid, and capped tigh
39、tly until tested. Sample handling should be minimized, and rapid testing for H2S is required.Samples can not be stored for later testing as H2S loss may occur by the mechanism described in Note 4.FIG. 1 Measurement of H2S in the Vapor Phase of Residual Fuel OilD5705 14310. Procedure10.1 Let each fil
40、led sample container sit at room temperature for at least 1 h, transfer part of its contents to an empty 1-L testbottle such that it is filled 50 % 6 5 volume % with the sample. Discard the remaining contents of the sample container incompliance with applicable laws. A single test is to be performed
41、 on material from an individual sample container.10.2 Insert a nitrogen purge line outlet to within about 13 mm above the fuel surface. Nitrogen purge at 2 L/min for 30 s theheadspace above the test sample to displace air and water vapor. Minimize the time the bottle is open to avoid further loss of
42、 samplevapors. Close the test bottle opening (gas tight) with a cork stopper fitted with a dial thermometer (Fig. 1(a) immediately afternitrogen purging.10.3 Place each test bottle with sample in an oven or a water bath, set at 60 6 1C, until the sample temperature reaches 606 1C. Keep the sample in
43、 the oven or bath for a minimum of 30 min, which includes the time for the sample to reach 60C.NOTE 5If the sample temperature does not reach 60C, low results will be obtained for the H2S concentration. If the temperature exceeds 60C, highresults will be obtained for the H2S concentration.10.4 While
44、 the sample is heating, place an unbroken length-of-stain detector tube in the hand-operated pump and test the pumpfor leaks. Consult the manufacturers instructions for leak check procedure details and for maintenance instructions if leaks aredetected. The leak check typically takes 1 min.10.5 Remov
45、e the test bottle from the oven and place it in the four-prong clamp of the shaker. Shake at 220 rpm for 3 min 61 s to achieve H2S equilibrium between the liquid and the vapor phase.10.6 Rest the test bottle on a flat surface, remove the stopper with the dial thermometer, and immediately seal the to
46、p of thebottle with aluminum foil.10.7 Select a detector tube with a range that best encompasses the expected H2S concentration. Reading accuracy is improvedwhen the stain length extends into the upper half of the calibration scale.10.8 Break off the tube tips and insert the tube into the pump, obse
47、rving the flow direction indication on the tube. Insert the tubethrough the aluminum foil on the test bottle. Rest the pump on top of the test bottle with the detector tube only contacting thesamples vapor phase. Do not allow the detector tube to contact the liquid, see Fig. 1(b). Use one full compr
48、ession stroke.10.9 Remove the detector tube after complete decompression of the pump and immediately read the H2S concentration fromthe tubes calibration scale or from the charts provided in the box of tubes. Read the tube at the maximum point of the stain. Ifchanneling has occurred (non-uniform sta
49、in length), read the maximum and minimum stain lengths and average the two readings.(WarningIf the calibration scale is not printed directly on the detector tube, be certain that any separate calibration chart is theproper match for the tube in use to avoid incorrect results.)10.10 If the calibration scale specifies more than one stroke, correct the reading as below:ppm v/vcorrected!5ppm v/vreading!3specified strokes (1)NOTE 6If the test is being conducted at an altitude above 610 m, corrections for barometric pressure are significant. I
