1、Designation: D7621 10IP 570Standard Test Method forDetermination of Hydrogen Sulfide in Fuel Oils by RapidLiquid Phase Extraction1, 2This standard is issued under the fixed designation D7621; the number immediately following the designation indicates the year oforiginal adoption or, in the case of r
2、evision, 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. Scope1.1 This test method covers a procedure for the determina-tion of the hydrogen sulfide (H2S) content
3、of fuel oils such asmarine residual fuels and blend stocks, in the range 0.40 to15.0 mg/kg as measured in the liquid phase.1.2 This test method is applicable for materials with aviscosity up to 3000 mm2s-1at 50C.NOTE 1ASTM specification fuels falling within the scope of this testmethod are: Specific
4、ation D396 Grade Nos 5 (light), 5 (heavy) and 6.1.3 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibilit
5、y 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:3D396 Specification for Fuel OilsD4057 Practice for Manual Sampling of Petroleum andPetroleum Product
6、sD5705 Test Method for Measurement of Hydrogen Sulfidein the Vapor Phase Above Residual Fuel OilsD6021 Test Method for Measurement of Total HydrogenSulfide in Residual Fuels by Multiple Headspace Extrac-tion and Sulfur Specific DetectionD6300 Practice for Determination of Precision and BiasData for
7、Use in Test Methods for Petroleum Products andLubricants2.2 ASTM Adjuncts:4ADJ6300 D2PP Determination of Precision and Bias datafor Use in Test Methods for Petroleum Products2.3 ISO Standards:5ISO TR 13739 Petroleum ProductsProcedures for theTransfer of Bunker Fuel(s) to ShipsISO 4259 Petroleum Prod
8、uctsDetermination and Applica-tion of Precision Data in Relation to Methods of Test2.4 Energy Institute Standards:6IP 399 Test Method for Determination of Hydrogen Sulfidein Fuel OilsIP 570 Test Method for Determination of Hydrogen Sulfidein Fuel OilsRapid Liquid Phase Extraction Method3. Terminolog
9、y3.1 Definitions:3.1.1 residual fuel oil, nfuel oil comprising a blend ofviscous long, short or cracked residue from a petroleumrefining process and lighter distillates (blend stocks) blended toa fuel oil viscosity specification, burned for the generation ofheat in a furnace or firebox or for the ge
10、neration of power in anengine.3.2 Definitions of Terms Specific to This Standard:3.2.1 liquid phase extraction, ntechnique to determine theconcentration of H2S gas trapped in a liquid by continuousanalysis of gases extracted by bubbling air through the testspecimen.4. Summary of Test Method4.1 A wei
11、ghed test specimen is introduced into a heated testvessel containing a diluent base oil. Air is bubbled through theoil to extract the H2S gas. The H2S is passed, with the air, over1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct
12、responsibility of SubcommitteeD02.E0.01 on Burner Fuels.Current edition approved May 1, 2010. Published August 2010.2This test method has been developed through the cooperative effort betweenASTM and the Energy Institute, London. The IP and ASTM logos imply that theASTM and IP standards are technica
13、lly equivalent, but their use does not imply thatboth standards are editorially identical.3For 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 Sum
14、mary page onthe ASTM website.4For referenced ASTM adjuncts contact ASTM Customer Service atserviceastm.org.5Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.6Available from Energy Institute, 61 New Cavendish St., London, WI
15、G 7AR,U.K., http:/www.energyinst.org.uk.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.an H2S specific electro-chemical detector to enable the H2Scontent of the air to be measured and the amount in the liquidphase to be calculated i
16、n mg/kg.5. Significance and Use5.1 Excessive levels of hydrogen sulfide in the vapor phaseabove residual fuel oils in storage tanks can result in healthhazards, violation of local occupational health and safetyregulations, and public complaint. An additional concern iscorrosion that can be caused by
17、 the presence of H2S duringrefining or other activities. Control measures to maintain safelevels of H2S require a precise method for the measurement ofpotentially hazardous levels of H2S in fuel oils. (WarningSafety. Hydrogen sulfide (H2S) is a very dangerous, toxic,explosive and flammable, colorles
18、s and transparent gas whichcan be found in crude oil and can be formed during themanufacture of the fuel at the refinery and can be releasedduring handling, storage, and distribution. At very low concen-trations, the gas has the characteristic smell of rotten eggs.However, at higher concentrations,
19、it causes a loss of smell,headaches, and dizziness, and at very high concentrations, itcauses instantaneous death. It is strongly recommended thatpersonnel involved in the testing for hydrogen sulfide areaware of the hazards of vapor-phase H2S and have in placeappropriate processes and procedures to
20、 manage the risk ofexposure.)5.2 This test method was developed so refiners, fuel termi-nal operators, and independent testing laboratory personnel canrapidly and precisely measure the amount of H2S in residualfuel oils and distillate blend stocks, with a minimum oftraining, in a wide range of locat
21、ions.5.3 Test Method D5705 provides a simple and consistentfield test method for the rapid determination of H2Sintheresidual fuel oils vapor phase. However it does not necessarilysimulate the vapor phase H2S concentration of a fuel storagetank nor does it provide any indication of the liquid phase H
22、2Sconcentration.5.4 Test Method D6021 does measure the H2S concentra-tion of H2S in the liquid phase, however it requires a laboratoryand a skilled operator to perform the complex procedure andcalculations, and does not offer any reproducibility data. Thistest method (D7621) offers a 15 min automate
23、d test, simplicity,full precision, and a degree of portability.5.5 H2S concentrations in the liquid and vapor phase at-tempt to reach equilibrium in a static system. However, thisequilibrium and the related liquid and vapor concentrations canvary greatly depending on temperature and the chemicalcomp
24、osition of the liquid phase. The equilibrium of the vaporphase is disrupted the moment a vent or access point is openedto collect a sample.6. Apparatus6.1 GeneralThe apparatus, as detailed in Annex A1,comprises an air pump, test vessel, heating jacket, filters, H2Sspecific detector, integral compute
25、r, automatic solenoid valves,gas flow detectors, a disposable syringe, anda1mLpositivedisplacement pipette.6.2 Analytical Balance, single pan or double pan balancecapable of weighing to the nearest 0.001 g.6.3 Syringe, 20 mL polypropylene disposable type, forintroduction of the diluent oil (see 7.1)
26、, accuracy 61%.6.4 Refrigerator (optional), for storing the test sample (see8.5). The refrigerator shall be of a type suitable for storingflammable, volatile materials.6.5 Oven/Water Bath (optional), for warming the sample to40C with an accuracy of 62C (see 9.4.2.1). The oven shallbe of a type suita
27、ble for use with volatile materials.7. Reagents and Materials7.1 Diluent Oil,7proprietary water white API Group 2 baseoil with a typical viscosity of 100 mm2s-1at 40 C.7.2 Reference Material,7pressurized nitrogen, of at least99.999 % (v/v) purity, containing a certified level of H2S(nominally 25 mg/
28、kg).7.3 Cleaning Materials, technical grade.7.3.1 Toluene.7.3.2 Petroleum Ether (60/80).7.3.3 Acetone.8. Sampling8.1 Unless otherwise agreed, samples shall be taken inaccordance with Practice D4057 or ISO TR 13739.8.2 During sampling operations, care shall be taken toensure that the integrity of the
29、 material is maintained and thepossible loss of H2S is kept to a minimum. The precision of thismethod is critically dependent on the sampling, thermal his-tory, and handling of the test sample.8.3 Draw the sample directly into a suitable clean H2S inertcontainer, of a minimum volume of 500 mL, with
30、an impervi-ous gas-tight closure. Suitable containers include amber glassbottles and epoxy lined containers. The closure aperture shallallow the drawing of a test specimen with the syringe or pipette(see A1.1.13 and A1.1.12).8.3.1 Epoxy lined containers shall be visually inspected toensure that the
31、lining has not been damaged and that thecontainers are not dented.8.3.2 To ensure sample integrity fill the sample container toapproximately 95 % full and cap immediately.NOTE 2Lower volume containers may be used, however the precisioncould be affected.8.4 If a dedicated H2S sample cannot be taken,
32、then the H2Smeasurement shall be the first test carried out on the sample asany additional handling can lead to loss of H2S and low results.8.5 Take the samples to the laboratory as soon as ispracticable after sampling. Test immediately if possible. Ifsamples are not tested immediately, store in a c
33、ool place suchas a refrigerator (6.4), and analyze within 3 days aftersampling.9. Preparation of Apparatus9.1 GeneralFollow the manufacturers instructions forthe correct set up, verification, calibration and operation of theapparatus.7The following reagents and materials were used to develop the pre
34、cisionstatements: Seta Diluent SA4000-004 and Seta Verification Gas SA4001-001.Stanhope-Seta, Chertsey, Surrey, KT16 8AP, UK. This is not an endorsement orcertification by ASTM International.D7621 1029.2 Location of ApparatusUse the apparatus under asuitable fume hood or equivalent well-ventilated w
35、ork space,and vent the gas exit tube to a suitable extractor as the test willrelease small amounts of H2S gas during test specimenintroduction and during the measurement.9.3 Filters:9.3.1 The inlet air filter shall be replaced every 3 months, orearlier if any discoloration is visible.9.3.2 Follow th
36、e manufacturers instructions regarding thereplacement intervals of the air pump and moisture filters.9.3.3 Replace the moisture filter if any discoloration isvisible.9.4 Sample Preparation:9.4.1 To minimize the loss of H2S gas, do not homogenizeor transfer the sample to another container, and avoid
37、shakingthe sample before taking a test specimen.9.4.2 The sample needs to be flowing freely enough to allowthe test specimen to be drawn into the syringe or pipette (seeA1.1.13 and A1.1.12).9.4.2.1 A sample that is not free flowing at ambient tem-perature shall be gently warmed in a water bath or ov
38、en (see6.5) set at a temperature not exceeding 40C.9.4.2.2 Samples with viscosities greater than 3000 mm2s-1at 50C may be tested, but the precision could be affected.9.4.3 By using a smaller volume of sample it is possible toextend the range of the instrument to over 200 mg/kg but theprecision could
39、 be affected.NOTE 3It has been found that samples with a viscosity over500 mm2s-1, at 50C, usually require warming.9.5 Test VesselClean the test vessel and screw cap beforeeach test. Fit the screw cap tightly.9.6 Liquid TrapEmpty and clean the liquid trap if anyliquid or discoloration is visible.9.7
40、 H2S DetectorFollow the manufacturers instructionsfor installing a new calibrated detector and verify the perfor-mance immediately afterwards as described in 10.2.3.NOTE 4Toluene, followed by petroleum ether (60/80), and acetone,are effective in cleaning the test vessel, cap, and liquid trap (see 7.
41、3).10. Calibration and Standardization10.1 Ensure that all of the manufacturers instructions forverification and calibration of the mechanical and electronicsystems, and operation of the apparatus are followed. Calibra-tion functions are separated from the usual operator controlsand are all implemen
42、ted electronically using the integraldisplay and keyboard.10.2 Verification:10.2.1 Air Flow RateVerify that the air flow rate is 375 655 mL/min, at least once a year using a suitable flow meterconnected to the air output connection. If the flow rate isincorrect, recalibrate the flow (see 10.3.1).10.
43、2.2 Test Vessel Heater JacketVerify that the tempera-ture of the heater jacket is 60.0 6 1.0 C, at least every sixmonths, by inserting a calibrated temperature sensor into theheater jacket. If the temperature is incorrect, recalibrate (see10.3.2).10.2.3 H2S DetectorVerify the performance of the dete
44、c-tor at least every month, or when a new detector is fitted, atzero using air, and at a nominal 25 mg/kg vapor concentrationlevel using pressurized nitrogen (see 7.2) containing a certifiedlevel of H2S.10.3 Calibration:10.3.1 Air Flow RateThe air flow adjustment is imple-mented electronically.10.3.
45、2 Test Vessel Heater JacketThe temperature adjust-ment is implemented electronically.10.3.3 H2S DetectorThe detector is factory calibratedusing the reference material (see 7.2) (static calibration) andusing factory calibration liquids with known mg/kg liquidconcentrations of H2S (dynamic calibration
46、). This calibrationinformation is held digitally on the detector assembly and isread directly by the computer in the apparatus. The calibrationenables results in mg/kg to be calculated from the test results.The dynamic calibration is a function of the detector andapparatus, and has a fixed value.10.
47、3.3.1 The static calibration is implemented electronicallyfollowing a verification (see 10.2.3).11. Procedure11.1 At switch on, the H2S apparatus shall control the testvessel heater jacket to 60.0 6 1.0 C, and purge by pumping airdirectly to the detector.11.2 Remove the screw cap from the cleaned te
48、st vessel (see9.5) and introduce 20.0 6 0.5 mL of diluent oil (see 7.1) usingthe syringe (see 6.3) and then replace the screw cap. Place thetest vessel in the temperature controlled heating jacket and fitthe input/output tubing.11.3 Air is pumped through the diluent in the test vessel andto the dete
49、ctor for 5 min. This allows the diluent oil to warmup, and the system to be purged.11.4 Air is then pumped directly to the detector, bypassingthe test vessel, to allow the test specimen to be introducedwithout purge air affecting the concentration of the H2S.Ensure that the instrument is operating in bypass mode beforeintroducing the test specimen. Introducing the test specimenbefore this condition is met will likely result in premature lossof H2S and an erroneously low result. If this is suspected or theinstrument indicates that an incorrect proc
