ASTM_D_1072_-_06_2012.pdf

Designation:D107206(Reapproved 2012)Standard Test Method forTotal Sulfur in Fuel Gases by Combustion and BariumChloride Titration1This standard is issued under the fixed designation D1072;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.Scope1.1 This test method is for the determination of total sulfurin combustible fuel gases,when present in sulfur concentra-tions between approximately 25 and 700 mg/m3(1 to 30 grainsper 100 cubic feet).It is applicable to natural gases,manufac-tured gases,mixed gases,and other miscellaneous gaseousfuels.1.2 The values stated in inch-pound units are to be regardedas standard.1.3 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:2D1193 Specification for Reagent Water3.Summary of Test Method3.1 A metered sample of gas is burned in a closed system inan atmosphere of sulfur-free air.The oxides of sulfur producedare absorbed in sodium carbonate solution,where they areoxidized to sulfate.The sulfate in the absorbent solution isdetermined by titration with standardized barium chloridesolution,using tetra-hydroxy-quinone(THQ)as an indicator.4.Interferences4.1 There are no known interferences for the determinationof total sulfur in fuel gases when combustion is followed bybarium chloride titration.However,users employing bariumchloride titration following collection of sulfur dioxide byalternative procedures are cautioned that ammonia,amines,substances producing water soluble cations,and fluorides willinterfere with the titration.5.Apparatus5.1 Burner(Fig.1),as specified in the Appendix X1.5.2 Chimneys,Absorbers and Spray Traps,(Fig.2),asspecified in the Appendix X1.5.3 Flow meterA calibrated capillary flow meter forpredetermining and indicating the rate of flow of gas to theburner.The capillary selected should be of such size that at therequired rate of flow the differential pressure is at least 20 cmof water.A scale divided into millimeters will then provide areading precision of 6 0.5%.Other metering devices,includ-ing but not limited to rotameters or dry displacement meters,are suitable provided the reading precision is 6 0.5%or better.A flow controlling valve is attached to the inlet connection ofthe flow meter.5.4 Vacuum SystemA vacuum manifold equipped with avacuum regulating device,valves,and other necessary accou-terments.An example vacuum system capable of performingmultiple test measurements is shown in Fig.3.Other vacuumsystem configurations can be used to perform this test method.The vacuum system shall be connected to a vacuum pumpcapable of providing a steady gas flow of 3 L of air per minutethrough each absorber and capable of maintaining a constantmanifold pressure of approximately 40 cm of water belowatmospheric pressure.5.5 Air-Purifying SystemA device supplying purified airto the burner manifold at a constant pressure of approximately200 mm of water and to the chimney manifold at a pressure of1 to 2 cm of water.An example system configuration formultiple tests is illustrated in Fig.4;however,other air-purifying system configurations can be used to perform this testmethod.The tubing that connects the chimneys to the manifoldshall be of an internal diameter not smaller than 0.63 cm inorder to prevent unnecessary restriction of airflow.5.6 ManometerA water manometer for indicating the gaspressure at the point of volume measurement.It is connectedbetween the flowmeter and the burner,with one leg open to theatmosphere.1This test method is under the jurisdiction ofASTM Committee D03 on GaseousFuels and is the direct responsibility of D03.05 on Determination of SpecialConstituents of Gaseous Fuels.Current edition approved Nov.1,2012.Published December 2012.Originallyapproved in 1954.Last previous edition approved in 2006 as D1072 06.DOI:10.1520/D1072-06R12.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 6.Reagents and Materials6.1 Reagents PurityReagent grade chemicals shall beused in all tests.Unless otherwise indicated,it is intended thatall reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,where such specifications are available.3Other grades may beused,provided it is first ascertained that the reagent i