ASTM_D_5705_-_20.pdf

Designation:D570520Standard 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 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-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 40 C to 50 mm2/s at 100 C.The testmethod is applicable to fuels conforming to Specification D396Grade Nos.4,5(Heavy),and 6.1.3 Theapplicablerangeisfrom5 mol molto4000 mol mol(micromoles per mole)(5 ppm v v to4000 ppm v/v(parts per million by volume).1.4 The values stated in SI units are to be regarded asstandard.The values given in parentheses 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,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.6 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D396 Specification for Fuel OilsD4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD4175 Terminology Relating to Petroleum Products,LiquidFuels,and LubricantsD6021 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 For definitions of terms used in this test method,seeTerminology D4175.3.1.2 equilibrium headspace,nthe vapor space above theliquid in which all vapor components are in equilibrium withthe liquid components.3.1.3 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 specification.3.1.3.1 DiscussionUnder the conditions of this test(1:1liquid/vapor ratio,temperature,and agitation)the H2S in thevapor 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 50%by volume with fuel oil from a filled H2S-inertcontainer(glass sample bottle)just prior to testing.In the testcontainer,the vapor space above the fuel oil sample is purgedwith nitrogen to displace air.The test container with sample isheated in an oven to 60 C,and agitated on an orbital shaker at3.67 s-16 0.08 s-1(220 r min 6 5 r min(revolutions perminute)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 oils can contain H2S in the liquid phaseand this can result in hazardous vapor phase levels of H2S instorage tank headspaces.The vapor phase levels can vary1This 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,Cleanliness and Compatibility of Liquid Fuels.Current edition approved Oct.1,2020.Published October 2020.Originallyapproved in 1995.Last previous edition approved in 2015 as D5705 15.DOI:10.1520/D5705-20.2For 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 website.*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 StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.significantly according to the headspace volume,fuel tempera-ture and agitation.Measurement of H2S levels in the liquidphase provides a useful indication of the residual fuel oilspropensity to form high vapor phas