ASTM_D_5160_-_95_2014.pdf

Designation:D516095(Reapproved 2014)Standard Guide forGas-Phase Adsorption Testing of Activated Carbon1This standard is issued under the fixed designation D5160;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 guide covers the evaluation of activated carbons forgas-phase adsorption.It presents a procedure for determiningthe dynamic adsorption capacity,No,and critical bed depth,dc,for an activated carbon used to remove a specific adsorbatefrom a gas stream under conditions chosen by the user.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 8.2.Referenced Documents2.1 ASTM Standards:2D2652 Terminology Relating to Activated CarbonD2854 Test Method for Apparent Density of ActivatedCarbonD2867 Test Methods for Moisture in Activated CarbonD3467 Test Method for Carbon Tetrachloride Activity ofActivated CarbonE300 Practice for Sampling Industrial Chemicals3.Terminology3.1 Definitions:3.1.1 breakthroughthe appearance in the effluent of aspecified concentration of an adsorbate of interest.3.1.2 Other terms relating to this guide are defined inTerminology D2652.4.Summary of Guide4.1 An activated carbon bed that contains a known amountof carbon is challenged with an adsorbate in a gas stream underconditions of flow rate,adsorbate concentration,temperature,pressure,and relative humidity set by the user.The time tobreakthrough of a specified concentration of adsorbate ismeasured.The measurement is repeated using the same con-ditions but varying the amount of carbon in the bed.For manypractical systems,a plot of breakthrough time versus amount ofcarbon is linear.The slope and x-intercept of this line can beused to calculate the dynamic capacity,No(expressed as gramsadsorbate/grams carbon or grams adsorbate/cm3carbon)andcritical bed depth,dc,characteristic of the activated carbonunder the conditions used in the test.5.Significance and Use5.1 Activated carbon is used extensively for removing gasesand vapors from air or other gas streams.The physical andchemical characteristics of an activated carbon can stronglyinfluence its suitability for a given application.The procedurein this guide allows the evaluation of the dynamic adsorptioncharacteristics of an activated carbon for a particular adsorbateunder conditions chosen by the user.It is necessary that theuser choose test conditions that are meaningful for the appli-cation(see Section 9).5.2 This guide can also be used to evaluate activatedcarbons that have been impregnated with materials to enhancetheir effectiveness at removing gases otherwise poorly ad-sorbed on activated carbon.5.3 The procedure given in this guide is not generallyapplicable for evaluation of carbons used as catalysts for suchpurposes as decomposition of low levels of ozone or oxidationof SO2to SO3.5.4 The procedure given in this guide can be applied toreactivated or regenerated activated carbons.5.5 Fig.1 shows the adsorbate concentration profile in anactivated carbon bed at breakthrough.The bed has a zone at theinlet in which the adsorbate concentration is equal to theinfluent concentration.In this region the carbon is at equilib-rium with adsorbate.The adsorbate concentration in theremainder of the bed drops until at the outlet it is equal to thebreakthrough concentration.The shorter the length of this mass1This guide is under the jurisdiction of ASTM Committee D28 on ActivatedCarbon and is the direct responsibility of Subcommittee D28.04 on Gas PhaseEvaluation Tests.Current edition approved July 1,2014.Published September 2014.Originallyapproved in 1991.Last previous edition approved in 2008 as D5160 95(2008).DOI:10.1520/D5160-95R14.2For 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 transfer zone(adsorption zone),the more effectively the carbonin the bed is utilized.A bed whose depth is less than the lengthof this zone will show immediate appearance of adsorbate inthe effluent(breakpoint).5.6 From the standpoint of best carbon utilization it isdesirable to choose a carbon which will give as short a masstransfer zone as possible under use conditions.However,inma