【英文标准名称】:StandardGuideforGas-PhaseAdsorptionTestingofActivatedCarbon
【原文标准名称】:活性碳气相吸收检验的标准指南
【标准号】:ASTMD5160-1995(2008)
【标准状态】:现行
【国别】:美国
【发布日期】:1995
【实施或试行日期】:
【发布单位】:美国材料与试验协会(US-ASTM)
【起草单位】:D28.04
【标准类型】:(Guide)
【标准水平】:()
【中文主题词】:
【英文主题词】:acceleratedtesting;activatedcarbon;criticalbeddepth;dynamicadsorptioncapacity;Activatedcarbon;Adsorption;Criticalbeddepth(dc);Dynamicadsorptioncapacity(No);Gas-phaseadsorption
【摘要】:Activatedcarbonisusedextensivelyforremovinggasesandvaporsfromairorothergasstreams.Thephysicalandchemicalcharacteristicsofanactivatedcarboncanstronglyinfluenceitssuitabilityforagivenapplication.Theprocedureinthisguideallowstheevaluationofthedynamicadsorptioncharacteristicsofanactivatedcarbonforaparticularadsorbateunderconditionschosenbytheuser.Itisnecessarythattheuserchoosetestconditionsthataremeaningfulfortheapplication(seeSection9).Thisguidecanalsobeusedtoevaluateactivatedcarbonsthathavebeenimpregnatedwithmaterialstoenhancetheireffectivenessatremovinggasesotherwisepoorlyadsorbedonactivatedcarbon.TheproceduregiveninthisguideisnotgenerallyapplicableforevaluationofcarbonsusedascatalystsforsuchpurposesasdecompositionoflowlevelsofozoneoroxidationofSO2toSO3.Theproceduregiveninthisguidecanbeappliedtoreactivatedorregeneratedactivatedcarbons.Fig.1showstheadsorbateconcentrationprofileinanactivatedcarbonbedatbreakthrough.Thebedhasazoneattheinletinwhichtheadsorbateconcentrationisequaltotheinfluentconcentration.Inthisregionthecarbonisatequilibriumwithadsorbate.Theadsorbateconcentrationintheremainderofthebeddropsuntilattheoutletitisequaltothebreakthroughconcentration.Theshorterthelengthofthismasstransferzone(adsorptionzone),themoreeffectivelythecarboninthebedisutilized.Abedwhosedepthislessthanthelengthofthiszonewillshowimmediateappearanceofadsorbateintheeffluent(breakpoint).Fromthestandpointofbestcarbonutilizationitisdesirabletochooseacarbonwhichwillgiveasshortamasstransferzoneaspossibleunderuseconditions.However,inmanyapplications,highadsorptivecapacityismoreimportantthanashortmasstransferzone.Inalmosteveryapplication,bedpressuredropisalsoaprimaryconsideration.Inafewsituationssuchasrespiratoryprotectionagainstlowlevelsofextremelytoxicgasessuchasradioactivemethyliodide,ashortmasstransferzone(thatis,highadsorptionratecoefficient)ismoreimportantthanultimatecapacity.Inothercasessuchassolventrecovery,ahighdynamiccapacityismoreimportant.Althoughthedesignofadsorberbedsisbeyondthescopeofthisguide,thefollowingpointsshouldbeconsidered.Thebeddiametershouldbeaslargeaspossibleinordertolowerthepressuredropandtomaximizetheamountofcarboninthebed.Subjecttopressuredropconstraints,thedeepestpossiblecarbonbedshouldbeused.Allelsebeingequal,theuseofsmallerparticlesizecarbonwillshortenthemasstransferzoneandimprovebedefficiencyattheexpenseofhigherpressuredrop.Ifpressuredropconsiderationsarecritical,someparticlemorphologiesofferlessresistancetoflowthanothers.Thetwoparametersobtainedbytheprocedureinthisguidecanbeusedasanaidinselectinganactivatedcarbonandinsizingtheadsorptionbedinwhichthiscarbonwillbeused.ThebestcarbonformostapplicationsshouldhaveahighdynamiccapacityfortheadsorbateNocoupledwithashortmasstransferzone(smalldc)whenevaluatedundertheoperatingconditionsanticipatedfortheadsorber.FIG.1ConcentrationProfileofanActivatedCarbonBedatBreakthrough1.1Thisguidecoverstheevaluationofactivatedcarbonsforgas-phaseadsorption.Itpresentsaprocedurefordeterminingthedynamicadsorptioncapacity,N