1、Designation: D7621 13D7621 14IP 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 ca
2、se of revision, 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 the determination of the hydrogen sulfid
3、e (H2S) content of fuel oils suchas marine residual fuels and blend stocks, with viscosity up to 3000 mm2s-1 at 50C, and marine distillate fuels, as measured inthe liquid phase.NOTE 1Specification fuels falling within the scope of this test method are: ASTM Specification D396, MIL-DTL-16884, and ISO
4、 8217.1.2 ProcedureAhas been shown to eliminate interferences such as thiols (mercaptans) and alkyl sulfides. Procedure B can giveelevated results if such interferences are present (see Annex A2).1.3 Valid ranges for the precision are given in Table 2 and Table 3. Measurements can be made outside th
5、ese ranges howeverprecision has not been determined.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 respo
6、nsibilityof 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:3D396 Specification for Fuel OilsD4057 Practice for Manual Sampling of Petroleum and Petroleum Pr
7、oductsD5705 Test Method for Measurement of Hydrogen Sulfide in the Vapor Phase Above Residual Fuel OilsD6021 Test Method for Measurement of Total Hydrogen Sulfide in Residual Fuels by Multiple Headspace Extraction and SulfurSpecific DetectionD6300 Practice for Determination of Precision and Bias Dat
8、a for Use in Test Methods for Petroleum Products and Lubricants2.2 ASTM Adjuncts:4ADJ6300 D2PP Determination of Precision and Bias data for Use in Test Methods for Petroleum Products2.3 ISO Standards:5ISO 4259 Petroleum ProductsDetermination and Application of Precision Data in Relation to Methods o
9、f TestISO 8217 Fuels (Class F) Specification of Marine Fuels2.4 Energy Institute Standards:6IP 399 Test Method for Determination of Hydrogen Sulfide in Fuel OilsIP 570 Test Method for Determination of Hydrogen Sulfide in Fuel OilsRapid Liquid Phase Extraction Method1 This test method is under the ju
10、risdiction of ASTM Committee D02 on Petroleum Products Products, Liquid Fuels, and Lubricants and is the direct responsibility ofSubcommittee D02.14 on Stability and Cleanliness of Liquid Fuels.Current edition approved May 1, 2013June 1, 2014. Published August 2013July 2014. Originally approved in 2
11、010. Last previous edition approved in 20122013 asD7621 12.D7621 13. DOI:10.1520/D7621-13.DOI:10.1520/D7621-14.2 This test method has been developed through the cooperative effort between ASTM and the Energy Institute, London. The IP and ASTM logos imply that the ASTMand IP standards are technically
12、 equivalent, but their use does not imply that both standards are editorially identical.3 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summar
13、y page on the ASTM website.4 For referenced ASTM adjuncts contact ASTM Customer Service at serviceastm.org.5 Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http:/www.ansi.org.6 Available from Energy Institute, 61 New Cavendish St., London,
14、 WIG 7AR, U.K., http:/www.energyinst.org.uk.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 not be technically possible to adequately depict all changes accurately,
15、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 end of this standardCopyright ASTM International, 100 Barr Harbor Drive,
16、PO Box C700, West Conshohocken, PA 19428-2959. United States12.5 U.S. Department of Defense Specifications:7MIL-DTL-16884 Fuel, Naval Distillate3. Terminology3.1 Definitions:3.1.1 residual fuel oil, nfuel oil comprising a blend of viscous long, short or cracked residue from a petroleum refining proc
17、essand lighter distillates (blend stocks) blended to a fuel oil viscosity specification, burned for the generation of heat in a furnace orfirebox or for the generation of power in an engine.3.2 Definitions of Terms Specific to This Standard:3.2.1 liquid phase extraction, ntechnique to determine the
18、concentration of H2S gas trapped in a liquid by continuous analysisof gases extracted by bubbling air through the test specimen.3.2.2 vapor phase processor, napparatus enabling low temperature removal of interfering vapors.3.2.2.1 DiscussionThe vapor phase processor holds a specific filter cartridge
19、 at 20C during the Procedure A test.4. Summary of Test Method4.1 A weighed test specimen is introduced into a heated test vessel containing a diluent base oil. Air is bubbled through the oilto extract the H2S gas. The air with the extracted H2S is passed, via a vapor phase processor (ProcedureAonly)
20、, to an H2S specificelectro-chemical detector enabling the H2S content of the air to be measured and the amount in the liquid phase to be calculatedin mg/kg. The filter cartridge (see 7.4) is not required for Procedure B.5. Significance and Use5.1 Excessive levels of hydrogen sulfide in the vapor ph
21、ase above residual fuel oils in storage tanks can result in health hazards,violation of local occupational health and safety regulations, and public complaint. An additional concern is corrosion that can becaused by the presence of H2S during refining or other activities. Control measures to maintai
22、n safe levels of H2S require a precisemethod for the measurement of potentially hazardous levels of H2S in fuel oils. (WarningSafety. Hydrogen sulfide (H2S) is avery dangerous, toxic, explosive and flammable, colorless and transparent gas which can be found in crude oil and can be formedduring the m
23、anufacture of the fuel at the refinery and can be released during handling, storage, and distribution. At very lowconcentrations, the gas has the characteristic smell of rotten eggs. However, at higher concentrations, it causes a loss of smell,headaches, and dizziness, and at very high concentration
24、s, it causes instantaneous death. It is strongly recommended that personnelinvolved in the testing for hydrogen sulfide are aware of the hazards of vapor-phase H2S and have in place appropriate processesand procedures to manage the risk of exposure.)5.2 This test method was developed so refiners, fu
25、el terminal operators, and independent testing laboratory personnel canrapidly and precisely measure the amount of H2S in residual fuel oils and distillate blend stocks, with a minimum of training, ina wide range of locations.5.3 Test Method D5705 provides a simple and consistent field test method f
26、or the rapid determination of H2S in the residualfuel oils vapor phase. However it does not necessarily simulate the vapor phase H2S concentration of a fuel storage tank nor doesit provide any indication of the liquid phase H2S concentration.5.4 Test Method D6021 does measure the H2S concentration o
27、f H2S in the liquid phase, however it requires a laboratory anda skilled operator to perform the complex procedure and calculations, and does not offer any reproducibility data. This test method(D7621) offers a 15 min automated test, simplicity, full precision, and a degree of portability.5.5 H2S co
28、ncentrations in the liquid and vapor phase attempt to reach equilibrium in a static system. However, this equilibriumand the related liquid and vapor concentrations can vary greatly depending on temperature and the chemical composition of theliquid phase. The equilibrium of the vapor phase is disrup
29、ted the moment a vent or access point is opened to collect a sample.6. Apparatus6.1 GeneralThe apparatus, as detailed in Annex A1, comprises an air pump, test vessel, heating jacket, filters, H2S specificdetector, integral computer, automatic solenoid valves and gas flow detectors.6.1.1 Procedure A
30、requires the use of a vapor phase processor capable of cooling a specific filter cartridge (see 7.4) to 20 62C.6.2 Analytical Balance, single pan or double pan balance capable of weighing to the nearest 0.001 g.7 Available online at https:/assist.dla.mil/quicksearch/ or http:/ or from the Standardiz
31、ation Document Order Desk, 700 Robbins Avenue, Building 4D,Philadelphia, PA 19111-5094.D7621 1426.3 Syringe or Burette, able to dispense 20 mL for introduction of the diluent oil (see 7.1), accuracy 61 %.6.4 Refrigerator (optional), for storing the test sample (see 8.3). The refrigerator shall be of
32、 a type suitable for storingflammable, volatile materials.6.5 Oven/Water Bath (optional), for warming the sample to 40C with an accuracy of 62C (see 8.4.1.1). The oven shall beof a type suitable for use with volatile materials.6.6 Pipette, 1 mL positive displacement pipette, for the introduction of
33、the test specimen. The accuracy as stated by themanufacturer should be typically 60.25 %.6.7 Disposable Syringe, 5 mL or 10 mL, for the introduction of the test specimen. Typical accuracy 61 %. This may be fittedwith a needle or extra tube to allow sample to be taken from 3 cm below the surface, if
34、appropriate.7. Reagents and Materials7.1 Diluent Oil,8 proprietary water white API Group 2 base oil with a typical viscosity of 100 mm2s-1 at 40C.7.2 Reference Material,Materials: pressurized nitrogen, of at least 99.999 % (v/v) purity, containing a certified level of H2S (23to 27 ppm (v/v) traceabl
35、e to a national standard.7.2.1 Reference material, pressurized nitrogen, of at least 99.999 % (v/v) purity, containing a certified level of H2S (23 to 27ppm (v/v) traceable to a national standard.7.2.2 Verification solution containing a known concentration of liquid phase hydrogen sulphide.7.3 Clean
36、ing 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 a sealed envelope, required for use in the vapor phase processorrequired for use in Procedure A only.8. Sampling and Test Specimen Preparation8.1 Unles
37、s otherwise agreed, samples shall be taken in accordance with Practice D4057.8.1.1 During sampling operations, care shall be taken to ensure that the integrity of the material is maintained and the possibleloss of H2S is kept to a minimum. The precision of this method is critically dependent on the
38、sampling, thermal history, andhandling of the test sample.8.1.2 Collect the sample directly in a suitable clean H2S inert container, of a minimum volume of 500 mL, with an imperviousgas-tight closure. Suitable containers include amber glass bottles and epoxy lined containers. The closure aperture sh
39、all allow thedrawing of a test specimen with the syringe or pipette (see 6.7 and 6.6).8.1.2.1 Epoxy lined containers shall be visually inspected to ensure that the lining has not been damaged and that the containersare not dented.8.1.3 To ensure sample integrity fill the sample container to approxim
40、ately 95 % full and cap immediately.8.1.4 Where samples are drawn in a manner which does not minimize vapor loss (for example, continuous drip sampling) collecta dedicated sample for H2S determination.8.1.5 When samples cannot be collected directly into the sample container, transfer the sample from
41、 the sampling device intothe sample container and ensure that H2S loss is kept to a minimum.NOTE 2The precision has not been determined for smaller volume containers.8.2 If a dedicated H2S sample cannot be taken, then the H2S measurement shall be the first test carried out on the sample asany additi
42、onal handling can lead to loss of H2S and low results.8.3 Take the samples to the laboratory as soon as is practicable after sampling. Test immediately if possible. If samples are nottested immediately, store in a cool place such as a refrigerator (6.4), and analyze within 3 days after sampling.8.4
43、Test Specimen PreparationTo minimize the loss of H2S gas, do not homogenize or transfer the sample to anothercontainer, and avoid shaking the sample before taking a test specimen.8.4.1 The sample needs to be flowing freely enough to allow the test specimen to be drawn into the syringe or pipette (se
44、e 6.7and 6.6).8.4.1.1 A sample that is not free flowing at ambient temperature shall be gently warmed in a water bath or oven (see 6.5) setat a temperature not exceeding 40C.8.4.2 Samples with viscosities greater than 3000 mm2s-1 at 50C may be tested, but the precision has not been determined.8 The
45、following reagents and materials were used to develop the precision statements: Seta Diluent SA4000-004 and Seta Verification Gas SA4001-001. Stanhope-Seta,Chertsey, Surrey, KT16 8AP, UK. This is not an endorsement or certification by ASTM International.D7621 143NOTE 3It has been found that samples
46、with a viscosity over 500 mm500 mm2s-1, at 50C, usually require warming.8.4.3 By using a smaller volume of sample it is possible to extend the range of the instrument to over 200 mg/kg but theprecision has not been determined.9. Preparation of Apparatus9.1 GeneralFollow the manufacturers instruction
47、s for the correct set up, verification, calibration and operation of theapparatus.9.2 Location of ApparatusUse the apparatus under a suitable fume hood or equivalent well-ventilated work space, and ventthe gas exit tube to a suitable extractor as the test will release small amounts of H2S gas during
48、 test specimen introduction andduring the measurement.9.3 Filters and Tubing:9.3.1 At the beginning of each test inspect the moisture filter and the liquid trap.9.3.1.1 Replace the moisture filter if any discoloration is visible.9.3.2 Replace the tubing that connects to the test vessel if any discol
49、oration is visible.9.3.3 The inlet air filter shall be replaced every 3 months, or earlier if any discoloration is visible.9.3.4 Follow the manufacturers instructions regarding the replacement intervals of the air pump and moisture filters.9.4 Test VesselBefore each test ensure that the test vessel and screw cap are clean and dry. Fit the screw cap tightly.9.5 Liquid TrapEmpty and clean the liquid trap if any liquid or discoloration is visible.NOTE 4Toluene, followed by petroleum ether (60/80), and acetone, are effective in c
