1、Designation: D7621 15IP 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 re
2、vision, 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 procedures (A and B) for thedetermination of the hydrogen sulfide (H2S) c
3、ontent of fuel oilssuch as marine residual fuels and blend stocks, with viscosityup to 3000 mm2s-1at 50 C, and marine distillate fuels, asmeasured in the liquid phase.NOTE 1Specification fuels falling within the scope of this test methodare: ASTM Specification D396, MIL-DTL-16884, and ISO 8217.1.2 P
4、rocedure A has been shown to eliminate interferencessuch as thiols (mercaptans) and alkyl sulfides. Procedure B cangive elevated results if such interferences are present (seeAnnex A2).NOTE 2A procedure for measuring the amount of hydrogen sulfide incrude oil can be found in Appendix X1. Full precis
5、ion for Appendix X1has not yet been determined.1.3 Valid ranges for the precision are given in Table 2 andTable 3. Measurements can be made outside these rangeshowever precision has not been determined.1.4 The values stated in SI units are to be regarded asstandard. Non-SI units given in parentheses
6、 are for informationonly.1.5 This standard does not purport to address all of thesafety concerns, if any, associated 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 pri
7、or to use.2. Referenced Documents2.1 ASTM Standards:3D396 Specification for Fuel OilsD4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD5705 Test Method for Measurement of Hydrogen Sulfidein the Vapor Phase Above Residual Fuel OilsD6021 Test Method for Measurement of Total Hydroge
8、nSulfide in Residual Fuels by Multiple Headspace Extrac-tion and Sulfur Specific DetectionD6300 Practice for Determination of Precision and BiasData for Use in Test Methods for Petroleum Products andLubricants2.2 ASTM Adjuncts:4ADJ6300 D2PP Determination of Precision and Bias datafor Use in Test Met
9、hods for Petroleum Products2.3 ISO Standards:5ISO 4259 Petroleum ProductsDetermination and Applica-tion of Precision Data in Relation to Methods of TestISO 8217 Fuels (Class F) Specification of Marine Fuels2.4 Energy Institute Standards:6IP 399 Test Method for Determination of Hydrogen Sulfidein Fue
10、l OilsIP 570 Test Method for Determination of Hydrogen Sulfidein Fuel OilsRapid Liquid Phase Extraction Method1This test method 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 C
11、leanliness of Liquid Fuels.Current edition approved April 15, 2015. Published May 2015. Originallyapproved in 2010. Last previous edition approved in 2014 as D7621 14.DOI:10.1520/D7621-15.2This test method has been developed through the cooperative effort betweenASTM and the Energy Institute, London
12、. The IP and ASTM logos imply that theASTM and IP standards are technically 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
13、of ASTMStandards volume information, refer to the standards Document Summary 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.ans
14、i.org.6Available from Energy Institute, 61 New Cavendish St., London, WIG 7AR,U.K., http:/www.energyinst.org.uk.*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 States12.5 U.S.
15、Department of Defense Specifications:7MIL-DTL-16884 Fuel, Naval Distillate3. Terminology3.1 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 viscosit
16、y specification, burned for the generation ofheat in a furnace or firebox or for the generation 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 gase
17、s extracted by bubbling air through the testspecimen.3.2.2 vapor phase processor, napparatus enabling lowtemperature removal of interfering vapors.3.2.2.1 DiscussionThe vapor phase processor holds aspecific filter cartridge at 20 C during the Procedure A test.4. Summary of Test Method4.1 A weighed t
18、est specimen is introduced into a heated testvessel containing a diluent base oil. Air is bubbled through theoil to extract the H2S gas. The air with the extracted H2Sispassed, via a vapor phase processor (Procedure A only), to anH2S specific electro-chemical detector enabling the H2S con-tent of th
19、e air to be measured and the amount in the liquidphase to be calculated in mg/kg. The filter cartridge (see 7.4)isnot required for Procedure B.5. Significance and Use5.1 Excessive levels of hydrogen sulfide in the vapor phaseabove residual fuel oils in storage tanks can result in healthhazards, viol
20、ation of local occupational health and safetyregulations, and public complaint. An additional concern iscorrosion that can be caused by the presence of H2S duringrefining or other activities. Control measures to maintain safelevels of H2S require a precise method for the measurement ofpotentially ha
21、zardous levels of H2S in fuel oils. (WarningSafety. Hydrogen sulfide (H2S) is a very dangerous, toxic,explosive and flammable, colorless 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,
22、 and distribution. At very lowconcentrations, the gas has the characteristic smell of rotteneggs. However, at higher concentrations, it causes a loss ofsmell, headaches, and dizziness, and at very highconcentrations, it causes instantaneous death. It is stronglyrecommended that personnel involved in
23、 the testing for hydro-gen sulfide are aware of the hazards of vapor-phase H2S andhave in place appropriate processes and procedures to managethe risk of exposure.)5.2 This test method was developed so refiners, fuel termi-nal operators, and independent testing laboratory personnel canrapidly and pr
24、ecisely measure the amount of H2S in residualfuel oils and distillate blend stocks, with a minimum oftraining, in a wide range of locations.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 n
25、ot necessarilysimulate the vapor phase H2S concentration of a fuel storagetank nor does it provide any indication of the liquid phase H2Sconcentration.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 perfo
26、rm the complex procedure andcalculations, and does not offer any reproducibility data. Thistest method (D7621) offers a 15 min automated 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.
27、 However, thisequilibrium and the related liquid and vapor concentrations canvary greatly depending on temperature and the chemicalcomposition 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
28、 apparatus, as detailed in Annex A1,comprises an air pump, test vessel, heating jacket, filters, H2Sspecific detector, integral computer, automatic solenoid valvesand gas flow detectors.6.1.1 Procedure A requires the use of a vapor phase proces-sor capable of cooling a specific filter cartridge (see
29、 7.4)to20 C 6 2 C.6.2 Analytical Balance, single pan or double pan balancecapable of weighing to the nearest 0.001 g.6.3 Syringe or Burette, able to dispense 20 mL for introduc-tion of the diluent oil (see 7.1), accuracy 61%.6.4 Refrigerator (optional), for storing the test sample (see8.3). The refr
30、igerator shall be of a type suitable for storingflammable, volatile materials.6.5 Oven/Water Bath (optional), for warming the sample to40 C with an accuracy of 62 C (see 8.4.1.1). The oven shallbe of a type suitable for use with volatile materials.6.6 Pipette, 1 mL positive displacement pipette, for
31、 theintroduction of the test specimen. The accuracy as stated by themanufacturer should be typically 60.25 %.6.7 Disposable Syringe, 5 mLor 10 mL, for the introductionof the test specimen. Typical accuracy 61 %. This may be7Available online at https:/assist.dla.mil/quicksearch/ or http:/ from the St
32、andardization Document Order Desk, 700 Robbins Avenue, Building4D, Philadelphia, PA 19111-5094.D7621 152fitted with a needle or extra tube to allow sample to be takenfrom 3 cm below the surface, if appropriate.7. Reagents and Materials7.1 Diluent Oil,8proprietary water white API Group 2 baseoil with
33、 a typical viscosity of 100 mm2s-1at 40 C.7.2 Reference Materials:7.2.1 Reference material, pressurized nitrogen, of at least99.999 % (volume percent) purity, containing a certified levelof H2S (23 mol mol (ppm v/v) to 27 mol mol (ppm v/v)traceable to a national standard.7.2.2 Verification solution
34、containing a known concentra-tion of liquid phase hydrogen sulfide.7.3 Cleaning Materials, technical grade.7.3.1 Toluene.7.3.2 Petroleum Ether (60/80).7.3.3 Acetone.7.4 Filter Cartridge, see Fig. A1.5, individually packed in asealed envelope, required for use in the vapor phase processorrequired for
35、 use in Procedure A only.8. Sampling and Test Specimen Preparation8.1 Unless otherwise agreed, samples shall be taken inaccordance with Practice D4057.8.1.1 During sampling operations, care shall be taken toensure that the integrity of the material is maintained and thepossible loss of H2S is kept t
36、o a minimum. The precision of thismethod is critically dependent on the sampling, thermalhistory, and handling of the test sample.8.1.2 Collect the sample directly in a suitable clean H2Sinert container, of a minimum volume of 500 mL, with animpervious gas-tight closure. Suitable containers include
37、am-ber glass bottles and epoxy lined containers. The closureaperture shall allow the drawing of a test specimen with thesyringe or pipette (see 6.7 and 6.6).8.1.2.1 Epoxy lined containers shall be visually inspected toensure that the lining has not been damaged and that thecontainers are not dented.
38、8.1.3 To ensure sample integrity fill the sample container toapproximately 95 % full and cap immediately.8.1.4 Where samples are drawn in a manner which does notminimize vapor loss (for example, continuous drip sampling)collect a dedicated sample for H2S determination.8.1.5 When samples cannot be co
39、llected directly into thesample container, transfer the sample from the sampling deviceinto the sample container and ensure that H2S loss is kept to aminimum.NOTE 3The precision has not been determined for smaller volumecontainers.8.2 If a dedicated H2S sample cannot be taken, then the H2Smeasuremen
40、t shall be the first test carried out on the sample asany additional handling can lead to loss of H2S and low results.8.3 Take the samples to the laboratory as soon as ispracticable after sampling. Test immediately if possible. Ifsamples are not tested immediately, store in a cool place suchas a ref
41、rigerator (6.4), and analyze within 3 days aftersampling.8.4 Test Specimen PreparationTo minimize the loss ofH2S gas, do not homogenize or transfer the sample to anothercontainer, and avoid shaking the sample before taking a testspecimen.8.4.1 The sample needs to be flowing freely enough to allowthe
42、 test specimen to be drawn into the syringe or pipette (see6.7 and 6.6).8.4.1.1 A sample that is not free flowing at ambient tem-perature shall be gently warmed in a water bath or oven (see6.5) set at a temperature not exceeding 40C.8.4.2 Samples with viscosities greater than 3000 mm2s-1at50 C may b
43、e tested, but the precision has not been determined.NOTE 4It has been found that samples with a viscosity over500 mm2s-1, at 50 C, usually require warming.8.4.3 By using a smaller volume of sample it is possible toextend the range of the instrument to over 200 mg kg but theprecision has not been det
44、ermined.9. Preparation of Apparatus9.1 GeneralFollow the manufacturers instructions for thecorrect set up, verification, calibration and operation of theapparatus.9.2 Location of ApparatusUse the apparatus under asuitable fume hood or equivalent well-ventilated work space,and vent the gas exit tube
45、to a suitable extractor as the test willrelease small amounts of H2S gas during test specimenintroduction and during the measurement.9.3 Filters and Tubing:9.3.1 At the beginning of each test inspect the moisture filterand the liquid trap.9.3.1.1 Replace the moisture filter if any discoloration isvi
46、sible.9.3.2 Replace the tubing that connects to the test vessel ifany discoloration is visible.9.3.3 The inlet air filter shall be replaced every 3 months, orearlier if any discoloration is visible.9.3.4 Follow the manufacturers instructions regarding thereplacement intervals of the air pump and moi
47、sture filters.9.4 Test VesselBefore each test ensure that the test vesseland screw cap are clean and dry. Fit the screw cap tightly.9.5 Liquid TrapEmpty and clean the liquid trap if anyliquid or discoloration is visible.NOTE 5Toluene, followed by petroleum ether (60/80), and acetone,are effective in
48、 cleaning the test vessel, cap, and liquid trap (see 7.3).9.6 H2S DetectorFollow the manufacturers instructionsfor installing a new calibrated detector and verify the perfor-mance immediately afterwards as described in 10.2.3.9.7 Switch on the apparatus in accordance with the manu-facturers instruct
49、ions.9.7.1 Procedure AAfter switch on, initiate the vapor phaseprocessor cooling.8The following reagents and materials were used to develop the precisionstatements: 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 1539.7.1.1 Confirm that the temperature of the heater jacket is60.0 C 6 1.0 C and the vapor phase processor is 20.0 C 62.0 C. Air purging of the H2S detector commences.9.7.2
