ASTM_D_2784_-_11.pdf

Designation:D278411Standard Test Method forSulfur in Liquefied Petroleum Gases(Oxy-Hydrogen Burneror Lamp)1This standard is issued under the fixed designation D2784;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 determination of total sulfurin liquefied petroleum gases containing more than 1 g/g.Specimens should not contain more than 100 g/g of halogens.1.2 To attain the quantitative detectability that the testmethod is capable of,stringent techniques must be employedand all possible sources of sulfur contamination must beeliminated.In particular,cleaning agents,such as commonhousehold detergents which contain sulfates,should beavoided.1.3 The values stated in SI units are to be regarded asstandard.The values given in parentheses are for informationonly.1.4 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 prior to use.2.Referenced Documents2.1 ASTM Standards:2D156 Test Method for Saybolt Color of Petroleum Products(Saybolt Chromometer Method)D1193 Specification for Reagent WaterD1265 Practice for Sampling Liquefied Petroleum(LP)Gases,Manual MethodD1266 Test Method for Sulfur in Petroleum Products(LampMethod)D1657 Test Method for Density or Relative Density of LightHydrocarbons by Pressure HydrometerE11 Specification for Woven Wire Test Sieve Cloth and TestSieves2.2 Energy Institute Standard:3IP 181Sampling Petroleum Gases,Including LiquefiedPetroleum Gases3.Summary of Test Method3.1 The sample is burned in an oxy-hydrogen burner,or ina lamp in a closed system in a carbon dioxide-oxygenatmosphere.The latter is not recommended for trace quantitiesof sulfur due to the inordinately long combustion times needed.The oxides of sulfur are absorbed and oxidized to sulfuric acidin a hydrogen peroxide solution.The sulfate ions are thendetermined by either of the following finishes:3.1.1 Barium Perchlorate TitrationThe sulfate is titratedwith barium perchlorate using a thorin-methylene blue mixedindicator.3.1.2 TurbidimetricThe sulfate is precipitated as bariumsulfate and the turbidity of a suspension of the precipitate ismeasured with a photometer.4.Significance and Use4.1 It is important to have the sulfur content of liquefiedpetroleum gases at low enough concentration to meet govern-ment regulations.The presence of sulfur can result in corrosionof metal surfaces.Sulfur can be poisonous to catalysts insubsequent processing.5.Apparatus5.1 Oxy-Hydrogen Combustion AssemblyThe two typeslisted below are recommended.Any combustion apparatusgiving equivalent results,however,is satisfactory.5.1.1 Wickbold-Type Combustion Apparatus,as shown inFig.1.5.1.2 Modified Beckman Burner-Type Apparatus,4,5asshown in Fig.2.Each of the above types of apparatus shallconsist of three parts:atomizer-burner,combustion chamber,1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products,Liquid Fuels,and Lubricants and is the direct responsibility ofSubcommittee D02.03 on Elemental Analysis.Current edition approved Jan.1,2011.Published February 2011.Originallyapproved in 1969.Last previous edition approved in 2006 as D278406.DOI:10.1520/D2784-11.2For 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.3Available from Energy Institute,61 New Cavendish St.,London,WIG 7AR,U.K.,http:/www.energyinst.org.uk.4The sole source of supply of the apparatus known to the committee at this timeis Scientific Glassblowing Co.,P.O.Box 18353,Houston,TX 77023.5If you are aware of alternative suppliers,please provide this information toASTM International Headquarters.Your comments will receive careful consider-ation at a meeting of the responsible technical committee,1which you may attend.*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 States1 and absorber with spray trap.A blowout safety port in thecombustion chamber is desirable.The remainder of the appa-ratus shall consist of a suitable support stand with the necessaryneedle valves and flow meters for precise control of oxygen,hydrogen,and vacuum.5.1.3 Safety ShieldA transparent shield shall be used toprotect the operator in the event an explosive mixture is formedin the combustion chamber.5.2 Apparatus for Lamp Combustion:5.2.1 Absorbers,Chimneys,and Spray Traps,as requiredare described in detail in An