ASTM_D_3467_-_04_2014.pdf

Designation:D346704(Reapproved 2014)Standard Test Method forCarbon Tetrachloride Activity of Activated Carbon1This standard is issued under the fixed designation D3467;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.INTRODUCTIONCarbon tetrachloride is classified as a class I ozone depleting substance by the U.S.EnvironmentalProtection Agency.Therefore,use of this test method is discouraged.Instead,the use of Test Method D5742 is recommended.The correlation obtained between n-butaneactivity values and carbon tetrachloride activity values is contained in that test method.21.Scope1.1 This test method covers the determination of the acti-vation level of activated carbon.Carbon tetrachloride(CCl4)activity is defined herein as the ratio(in percent)of the weightof CCl4adsorbed by an activated carbon sample to the weightof the sample,when the carbon is saturated with CCl4underconditions listed in this test method.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.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.Specific hazardsstatements are given in Section 7.2.Referenced Documents2.1 ASTM Standards:3D2652 Terminology Relating to Activated CarbonD2854 Test Method for Apparent Density of ActivatedCarbonD2867 Test Methods for Moisture in Activated CarbonD5742 Test Method for Determination of Butane Activity ofActivated CarbonE300 Practice for Sampling Industrial ChemicalsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3.Terminology3.1 DefinitionsTerms relating to this test method aredefined in Terminology D2652.4.Summary of Test Method4.1 Activity is determined by flowing CCl4-laden airthrough a sample of carbon of known weight,under specifiedconditions,until there is no further increase in the weight of thesample,then determining the weight of the CCl4adsorbed.Theapparatus required for the test consists essentially of means tocontrol the supply air pressure,to remove oil and water in bothliquid and vapor states from the supply air,to produce thespecified concentration of CCl4in the air flowed through thecarbon sample,and to control the flow rate of the gas(air+CCl4)mixture through the sample.5.Significance and Use5.1 Activity as measured by this test method is basically ameasure of the pore volume of the activated carbon sample.This test method is therefore a means of determining the degreeof completion of the activation process,hence a useful meansof quality control for gas-phase activated carbons.This activitynumber does not necessarily provide an absolute or relativemeasure of the effectiveness of the tested carbon on otheradsorbates,or at other conditions of operation.6.Apparatus and Materials6.1 Carbon Tetrachloride,reagent grade.6.2 Supply of Clean,Dry,Oil-Free AirThe air must bepassed through a HEPA filter and a bed of activated carboncontaining at least 500 mL of carbon per 1670 mL/min of airflow.Relative humidity of the air must be less than 5%at25C.1This test method is under the jurisdiction of ASTM Committee D28 onActivated Carbon and is the direct responsibility of Subcommittee D28.04 on GasPhase Evaluation Tests.Current edition approved July 1,2014.Published September 2014.Originallyapproved in 1976.Last previous edition approved in 2009 as D3467 04(2009).DOI:10.1520/D3467-04R14.2The data for this correlation is available from ASTM International Headquar-ters.Request RR:D281000.3For 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 6.3 Balance,capable of weighing to within 610 mg.6.4 Pressure Regulator.6.5 CCl4Gas-Generating Device,capable of maintaining aCCl4concentration of 250 6 10 mg/L in the air stream at atemperature of 25 6 1C,equivalent to a relative saturation of27.5%.A typical generation device,shown in Fig.1,consistsof a gas-washing bottle and a refrigerated bath capable ofmaintaining a bath temperature of 0C.See also Table 1.6.6 Stopcock,three-way.6.7 Regulating Valve,needle valve,flowmeter,and clock.6.8 Adsorption Tube having the critical dimensions shownin Fig.1.6.9 Thermostat,capable of maintaining the CCl4-laden airstream and sample tube at a temperature of 25 6 1C.7.Hazards7.1 Carbon tetrachloride vapor is toxic and