activated carbon
DESCRIPTION
Activated carbon details are provided in this document. Uses of activated carbon and purification process is given.TRANSCRIPT
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Activatedcarbon
ActivatedcarbonFromWikipedia,thefreeencyclopedia
Activatedcarbon,alsocalledactivatedcharcoal,activatedcoal,orcarboactivatus,isaformofcarbonprocessedtohavesmall,lowvolumeporesthatincreasethesurfaceareaavailableforadsorptionorchemicalreactions.[1]Activatedissometimessubstitutedwithactive.
Duetoitshighdegreeofmicroporosity,justonegramofactivatedcarbonhasasurfaceareainexcessof500m2,asdeterminedbygasadsorption.Anactivationlevelsufficientforusefulapplicationmaybeattainedsolelyfromhighsurfaceareahowever,furtherchemicaltreatmentoftenenhancesadsorptionproperties.
Activatedcarbonisusuallyderivedfromcharcoaland,increasingly,highporositybiochar.
Contents
1Uses1.1Medicaluses1.2Adversedrugeffects1.3Analyticalchemistryapplications1.4Environmentalapplications1.5Fuelstorage1.6Gaspurification1.7Chemicalpurification1.8Soundabsorption1.9Distilledalcoholicbeveragepurification1.10Mercuryscrubbing
1.10.1DisposalintheUSAafterabsorbingmercury2Production3Classification
3.1Powderedactivatedcarbon(R1,PAC)3.2Granularactivatedcarbon(GAC)3.3Extrudedactivatedcarbon(EAC)3.4Beadactivatedcarbon(BAC)3.5Impregnatedcarbon
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3.6Polymercoatedcarbon3.7Other
4Properties4.1Iodinenumber4.2Molasses4.3Tannin4.4Methyleneblue4.5Dechlorination4.6Apparentdensity4.7Hardness/abrasionnumber4.8Ashcontent4.9Carbontetrachlorideactivity4.10Particlesizedistribution
5Modificationofpropertiesandreactivity6Examplesofadsorption
6.1Heterogeneouscatalysis6.2Absorptionrefrigeration
7Reactivationandregeneration7.1Thermalreactivation7.2Otherregenerationtechniques
8Seealso9References10Externallinks
Uses
Activatedcarbonisusedingaspurification,decaffeination,goldpurification,metalextraction,waterpurification,medicine,sewagetreatment,airfiltersingasmasksandrespirators,filtersincompressedairandmanyotherapplications.
Onemajorindustrialapplicationinvolvesuseofactivatedcarboninthemetalfinishingfield.Itisverywidelyemployedforpurificationofelectroplatingsolutions.Forexample,itisamainpurificationtechniqueforremovingorganicimpuritiesfrombrightnickelplatingsolutions.Avarietyoforganicchemicalsareaddedtoplatingsolutionsforimprovingtheirdepositqualitiesandforenhancingpropertieslikebrightness,smoothness,ductility,etc.Duetopassageofdirectcurrentandelectrolyticreactionsofanodicoxidationandcathodicreduction,organicadditivesgenerateunwantedbreakdownproductsinsolution.Theirexcessivebuildupcanadverselyaffecttheplatingqualityandphysicalpropertiesofdepositedmetal.Activatedcarbontreatmentremovessuchimpuritiesandrestoresplatingperformancetothedesiredlevel.
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Activatedcharcoalformedicaluse
Medicaluses
Activatedcarbonisusedtotreatpoisoningsandoverdosesfollowingoralingestion.Itisnoteffectiveforanumberofpoisoningsincluding:strongacidsoralkali,cyanide,iron,lithium,arsenic,methanol,ethanolorethyleneglycol.[2]
Tabletsorcapsulesofactivatedcarbonareusedinmanycountriesasanoverthecounterdrugtotreatdiarrhea,indigestion,andflatulence.
Adversedrugeffects
Incorrectapplication(e.g.intothelungs)resultsinpulmonaryaspirationwhichcansometimesbefatalifimmediatemedicaltreatmentisnotinitiated.[3]Theuseofactivatedcarboniscontraindicatedwhentheingestedsubstanceisanacid,analkali,orapetroleumproduct.
Analyticalchemistryapplications
Activatedcarbon,in50%w/wcombinationwithcelite,isusedasstationaryphaseinlowpressurechromatographicseparationofcarbohydrates(mono,ditrisaccharides)usingethanolsolutions(550%)asmobilephaseinanalyticalorpreparativeprotocols.
Environmentalapplications
Carbonadsorptionhasnumerousapplicationsinremovingpollutantsfromairorwaterstreamsbothinthefieldandinindustrialprocessessuchas:
SpillcleanupGroundwaterremediationDrinkingwaterfiltrationAirpurificationVolatileorganiccompoundscapturefrompainting,drycleaning,gasolinedispensingoperations,andotherprocesses.
In2007,UGent(GhentUniversity,Belgium)beganresearchinwatertreatmentafterfestivals.[4]AfullscaleactivatedcarboninstallationwasbuiltattheDranoutermusicfestivalin2008,withplanstoutilizethetechnologytotreatwateratthisfestivalforthenext20years.[4]
Activatedcarbonisalsousedforthemeasurementofradonconcentrationinair.
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Activatedcarbonisusuallyusedinwaterfiltrationsystems.Inthisillustration,theactivatedcarbonisinthefourthlevel(countedfrombottom).
Fuelstorage
Researchisbeingdonetestingvariousactivatedcarbons'abilitytostorenaturalgasandhydrogengas.Theporousmaterialactslikeaspongefordifferenttypesofgases.ThegasisattractedtothecarbonmaterialviaVanderWaalsforces.Somecarbonshavebeenabletoachievebondingenergiesof510kJpermol.Thegasmaythenbedesorbedwhensubjectedtohighertemperaturesandeithercombustedtodoworkorinthecaseofhydrogengasextractedforuseinahydrogenfuelcell.Gasstorageinactivatedcarbonsisanappealinggasstoragemethodbecausethegascanbestoredinalowpressure,lowmass,lowvolumeenvironmentthatwouldbemuchmorefeasiblethanbulkyonboardcompressiontanksinvehicles.TheUnitedStatesDepartmentofEnergyhasspecifiedcertaingoalstobeachievedintheareaofresearchanddevelopmentofnanoporouscarbonmaterials.Allofthegoalsareyettobesatisfiedbutnumerousinstitutions,includingtheALLCRAFTprogram,[5]arecontinuingtoconductworkinthispromisingfield.
Gaspurification
Filterswithactivatedcarbonareusuallyusedincompressedairandgaspurificationtoremoveoilvapours,odour,andotherhydrocarbonsfromtheair.Themostcommondesignsusea1stageor2stagefiltrationprincipleinwhichactivatedcarbonisembeddedinsidethefiltermedia.ActivatedcarbonisalsousedinspacesuitPrimaryLifeSupportSystems.Activatedcarbonfiltersareusedtoretainradioactivegasesfromanuclearboilingwaterreactorturbinecondenser.Theairvacuumedfromthecondensercontainstracesofradioactivegases.Thelargecharcoalbedsabsorbthesegasesandretainthemwhiletheyrapidlydecaytononradioactivesolidspecies.Thesolidsaretrappedinthecharcoalparticles,whilethefilteredairpassesthrough.
Chemicalpurification
Activatedcarboniscommonlyusedonthelaboratoryscaletopurifysolutionsoforganicmoleculescontainingunwantedcoloredorganicimpurities.
Soundabsorption
Activatedcarboncanfilterairandwater.Soundenergyisfoundwithinairandwaterandactivatedcarboncanbeusedtoabsorbthatenergy.Withthehighdegreeofporosityineachactivatedcarbongranule,soundenergyhasnumerousareastoenterintoandbeconvertedtoheat.Withtheenergychangetoheat,theprocessofsoundabsorptionoccurs.
Activatedcarboninitsgranuleformcanbeusedtoabsorbmiddleandhighfrequencyrangesprovidedtheabsorber'sdesignletsairpassthroughthecarbon.Activatedcarboncanalsobeusedinsideofdiaphragmaticabsorptiontechnologytoincreasetherateofabsorptionwithinthediaphragmaticabsorber.[6]
Distilledalcoholicbeveragepurification
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Activatedcarbonfilterscanbeusedtofiltervodkaandwhiskeyoforganicimpuritieswhichcanaffectcolor,taste,andodor.Passinganorganicallyimpurevodkathroughanactivatedcarbonfilterattheproperflowratewillresultinvodkawithanidenticalalcoholcontentandsignificantlyincreasedorganicpurity,asjudgedbyodorandtaste.
Mercuryscrubbing
Activatedcarbon,ofteninfusedwithsulfur[7]oriodine,iswidelyusedtotrapmercuryemissionsfromcoalfiredpowerstations,medicalincinerators,andfromnaturalgasatthewellhead.ThiscarbonisaspecialtyproductcostingmorethanUS$4.00perkg.However,itisoftennotrecycled.
DisposalintheUSAafterabsorbingmercury
Themercuryladenactivatedcarbonpresentsadisposaldilemma.[8]Iftheactivatedcarboncontainslessthan260ppmmercury,UnitedStatesfederalregulationsallowittobestabilized(forexample,trappedinconcrete)forlandfilling.However,wastecontaininggreaterthan260ppmisconsideredtobeinthehighmercurysubcategoryandisbannedfromlandfilling(LandBanRule).Thismaterialisnowaccumulatinginwarehousesandindeepabandonedminesatanestimatedrateof1000tonsperyear.
TheproblemofdisposalofmercuryladenactivatedcarbonisnotuniquetotheUnitedStates.IntheNetherlands,thismercuryislargelyrecovered[9]andtheactivatedcarbonisdisposedofbycompleteburning.
Production
Activatedcarboniscarbonproducedfromcarbonaceoussourcematerialssuchasnutshells,coconuthusk,peat,wood,coir,lignite,coal,andpetroleumpitch.Itcanbeproducedbyoneofthefollowingprocesses:
1. Physicalreactivation:Thesourcematerialisdevelopedintoactivatedcarbonsusinghotgases.Thisisgenerallydonebyusingoneoracombinationofthefollowingprocesses:
Carbonization:Materialwithcarboncontentispyrolyzedattemperaturesintherange600900C,usuallyininertatmospherewithgaseslikeargonornitrogenActivation/Oxidation:Rawmaterialorcarbonizedmaterialisexposedtooxidizingatmospheres(oxygenorsteam)attemperaturesabove250C,usuallyinthetemperaturerangeof6001200C.
2. Chemicalactivation:Priortocarbonization,therawmaterialisimpregnatedwithcertainchemicals.
Thechemicalistypicallyanacid,strongbase,orasalt[10](phosphoricacid,potassiumhydroxide,sodiumhydroxide,calciumchloride,andzincchloride25%).Then,therawmaterialiscarbonizedatlowertemperatures(450900C).Itisbelievedthatthecarbonization/activationstepproceedssimultaneouslywiththechemicalactivation.Chemicalactivationispreferredoverphysicalactivationowingtothelowertemperaturesandshortertimeneededforactivatingmaterial.
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Amicrographofactivatedcharcoal(R1)underbrightfieldilluminationonalightmicroscope.Noticethefractallikeshapeoftheparticleshintingattheirenormoussurfacearea.Eachparticleinthisimage,despitebeingonlyaround0.1mmacross,hasasurfaceareaofseveralsquaremetres.[11]Theentireimagecoversaregionofapproximately1.1by0.7mm,andthefullresolutionversionisatascaleof6.236pixels/m.
Classification
Activatedcarbonsarecomplexproductswhicharedifficulttoclassifyonthebasisoftheirbehaviour,surfacecharacteristicsandotherfundamentalcriteria.However,somebroadclassificationismadeforgeneralpurposebasedontheirsize,preparationmethods,andindustrialapplications.
Powderedactivatedcarbon(R1,PAC)
Normally,activatedcarbons(R1)aremadeinparticulateformaspowdersorfinegranuleslessthan1.0mminsizewithanaveragediameterbetween0.15and0.25mm.Thustheypresentalargesurfacetovolumeratiowithasmalldiffusiondistance.Activatedcarbon(R1)isdefinedastheactivatedcarbonparticlesretainedona50meshsieve(0.297mm).
PACmaterialisfinermaterial.PACismadeupofcrushedorgroundcarbonparticles,95100%ofwhichwillpassthroughadesignatedmeshsieve.TheASTMclassifiesparticlespassingthroughan80meshsieve(0.177mm)andsmallerasPAC.ItisnotcommontousePACinadedicatedvessel,duetothehighheadlossthatwouldoccur.Instead,PACisgenerallyaddeddirectlytootherprocessunits,suchasrawwaterintakes,rapidmixbasins,clarifiers,andgravityfilters.
Granularactivatedcarbon(GAC)
Granularactivatedcarbonhasarelativelylargerparticlesizecomparedtopowderedactivatedcarbonandconsequently,presentsasmallerexternalsurface.Diffusionoftheadsorbateisthusanimportantfactor.Thesecarbonsaresuitableforabsorptionofgasesandvapors,becausetheydiffuserapidly.Granulatedcarbonsareusedforwatertreatment,deodorizationandseparationofcomponentsofflowsystemandisalsousedinrapidmixbasins.GACcanbeeitheringranularorextrudedform.GACisdesignatedbysizessuchas820,2040,or830forliquidphaseapplicationsand46,48or410forvaporphaseapplications.A2040carbonismadeofparticlesthatwillpassthroughaU.S.StandardMeshSizeNo.20sieve(0.84mm)(generallyspecifiedas85%passing)butberetainedonaU.S.StandardMeshSizeNo.40sieve(0.42mm)(generallyspecifiedas95%retained).AWWA(1992)B604usesthe50meshsieve(0.297mm)astheminimumGACsize.Themostpopularaqueousphasecarbonsarethe1240and830sizesbecausetheyhaveagoodbalanceofsize,surfacearea,andheadlosscharacteristics.
Extrudedactivatedcarbon(EAC)
Extrudedactivatedcarboncombinespowderedactivatedcarbonwithabinder,whicharefusedtogetherandextrudedintoacylindricalshapedactivatedcarbonblockwithdiametersfrom0.8to130mm.Thesearemainlyusedforgasphaseapplicationsbecauseoftheirlowpressuredrop,highmechanicalstrengthandlowdustcontent.AlsosoldasCTOfilter(Chlorine,Taste,Odor).
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Amicrographofactivatedcharcoal(GAC)underscanningelectronmicroscope
Beadactivatedcarbon(BAC)
Beadactivatedcarbonismadefrompetroleumpitchandsuppliedindiametersfromapproximately0.35to0.80mm.SimilartoEAC,itisalsonotedforitslowpressuredrop,highmechanicalstrengthandlowdustcontent,butwithasmallergrainsize.Itssphericalshapemakesitpreferredforfluidizedbedapplicationssuchaswaterfiltration.
Impregnatedcarbon
Porouscarbonscontainingseveraltypesofinorganicimpregnatesuchasiodine,silver,cationssuchasAl,Mn,Zn,Fe,Li,Cahavealsobeenpreparedforspecificapplicationinairpollutioncontrolespeciallyinmuseumsandgalleries.Duetoitsantimicrobialandantisepticproperties,silverloadedactivatedcarbonisusedasanadsorbentforpurificationofdomesticwater.DrinkingwatercanbeobtainedfromnaturalwaterbytreatingthenaturalwaterwithamixtureofactivatedcarbonandAl(OH)3,aflocculatingagent.ImpregnatedcarbonsarealsousedfortheadsorptionofHydrogenSulfide(H2S)andthiols.AbsorptionratesforH2Sashighas50%byweighthavebeenreported.
Polymercoatedcarbon
Thisisaprocessbywhichaporouscarboncanbecoatedwithabiocompatiblepolymertogiveasmoothandpermeablecoatwithoutblockingthepores.Theresultingcarbonisusefulforhemoperfusion.Hemoperfusionisatreatmenttechniqueinwhichlargevolumesofthepatient'sbloodarepassedoveranadsorbentsubstanceinordertoremovetoxicsubstancesfromtheblood.
Other
Activatedcarbonisalsoavailableinspecialformssuchasclothsandfibres.The"carboncloth"forinstanceisusedinpersonnelprotectionforthemilitary.
Properties
Agramofactivatedcarboncanhaveasurfaceareainexcessof500m2,with1500m2beingreadilyachievable.[12]Carbonaerogels,whilemoreexpensive,haveevenhighersurfaceareas,andareusedinspecialapplications.
Underanelectronmicroscope,thehighsurfaceareastructuresofactivatedcarbonarerevealed.Individualparticlesareintenselyconvolutedanddisplayvariouskindsofporositytheremaybemanyareaswhereflatsurfacesofgraphitelikematerialrunparalleltoeachother,separatedbyonlyafewnanometersorso.Thesemicroporesprovidesuperbconditionsforadsorptiontooccur,sinceadsorbingmaterialcaninteract
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withmanysurfacessimultaneously.Testsofadsorptionbehaviourareusuallydonewithnitrogengasat77Kunderhighvacuum,butineverydaytermsactivatedcarbonisperfectlycapableofproducingtheequivalent,byadsorptionfromitsenvironment,liquidwaterfromsteamat100C(212F)andapressureof1/10,000ofanatmosphere.
JamesDewar,thescientistafterwhomtheDewar(vacuumflask)isnamed,spentmuchtimestudyingactivatedcarbonandpublishedapaperregardingitsadsorptioncapacitywithregardtogases.[13]Inthispaper,hediscoveredthatcoolingthecarbontoliquidnitrogentemperaturesallowedittoadsorbsignificantquantitiesofnumerousairgases,amongothers,thatcouldthenberecollectedbysimplyallowingthecarbontowarmagainandthatcoconutbasedcarbonwassuperiorfortheeffect.Heusesoxygenasanexample,whereintheactivatedcarbonwouldtypicallyadsorbtheatmosphericconcentration(21%)understandardconditions,butreleaseover80%oxygenifthecarbonwasfirstcooledtolowtemperatures.
Physically,activatedcarbonbindsmaterialsbyvanderWaalsforceorLondondispersionforce.
Activatedcarbondoesnotbindwelltocertainchemicals,includingalcohols,diols,strongacidsandbases,metalsandmostinorganics,suchaslithium,sodium,iron,lead,arsenic,fluorine,andboricacid.
Activatedcarbonadsorbsiodineverywell.Theiodinecapacity,mg/g,(ASTMD28StandardMethodtest)maybeusedasanindicationoftotalsurfacearea.
Carbonmonoxideisnotwelladsorbedbyactivatedcarbon.Thisshouldbeofparticularconcerntothoseusingthematerialinfiltersforrespirators,fumehoodsorothergascontrolsystemsasthegasisundetectabletothehumansenses,toxictometabolismandneurotoxic.
Substantiallistsofthecommonindustrialandagriculturalgasesadsorbedbyactivatedcarboncanbefoundonline.[14]
Activatedcarboncanbeusedasasubstratefortheapplicationofvariouschemicalstoimprovetheadsorptivecapacityforsomeinorganic(andproblematicorganic)compoundssuchashydrogensulfide(H2S),ammonia(NH3),formaldehyde(HCOH),mercury(Hg)andradioactiveiodine131(131I).Thispropertyisknownaschemisorption.
Iodinenumber
Manycarbonspreferentiallyadsorbsmallmolecules.Iodinenumberisthemostfundamentalparameterusedtocharacterizeactivatedcarbonperformance.Itisameasureofactivitylevel(highernumberindicateshigherdegreeofactivation),oftenreportedinmg/g(typicalrange5001200mg/g).Itisameasureofthemicroporecontentoftheactivatedcarbon(0to20,orupto2nm)byadsorptionofiodinefromsolution.Itisequivalenttosurfaceareaofcarbonbetween900m/gand1100m/g.Itisthestandardmeasureforliquidphaseapplications.
Iodinenumberisdefinedasthemilligramsofiodineadsorbedbyonegramofcarbonwhentheiodineconcentrationintheresidualfiltrateis0.02normal.Basically,iodinenumberisameasureoftheiodineadsorbedintheporesand,assuch,isanindicationoftheporevolumeavailableintheactivatedcarbonofinterest.Typically,watertreatmentcarbonshaveiodinenumbersrangingfrom600to1100.Frequently,thisparameterisusedtodeterminethedegreeofexhaustionofacarboninuse.However,thispracticeshouldbeviewedwithcautionaschemicalinteractionswiththeadsorbatemayaffecttheiodineuptakegiving
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falseresults.Thus,theuseofiodinenumberasameasureofthedegreeofexhaustionofacarbonbedcanonlyberecommendedifithasbeenshowntobefreeofchemicalinteractionswithadsorbatesandifanexperimentalcorrelationbetweeniodinenumberandthedegreeofexhaustionhasbeendeterminedfortheparticularapplication.
Molasses
Somecarbonsaremoreadeptatadsorbinglargemolecules.Molassesnumberormolassesefficiencyisameasureofthemesoporecontentoftheactivatedcarbon(greaterthan20,orlargerthan2nm)byadsorptionofmolassesfromsolution.Ahighmolassesnumberindicatesahighadsorptionofbigmolecules(range95600).Carameldp(decolorizingperformance)issimilartomolassesnumber.Molassesefficiencyisreportedasapercentage(range40%185%)andparallelsmolassesnumber(600=185%,425=85%).TheEuropeanmolassesnumber(range525110)isinverselyrelatedtotheNorthAmericanmolassesnumber.
MolassesNumberisameasureofthedegreeofdecolorizationofastandardmolassessolutionthathasbeendilutedandstandardizedagainststandardizedactivatedcarbon.Duetothesizeofcolorbodies,themolassesnumberrepresentsthepotentialporevolumeavailableforlargeradsorbingspecies.Asalloftheporevolumemaynotbeavailableforadsorptioninaparticularwastewaterapplication,andassomeoftheadsorbatemayentersmallerpores,itisnotagoodmeasureoftheworthofaparticularactivatedcarbonforaspecificapplication.Frequently,thisparameterisusefulinevaluatingaseriesofactivecarbonsfortheirratesofadsorption.Giventwoactivecarbonswithsimilarporevolumesforadsorption,theonehavingthehighermolassesnumberwillusuallyhavelargerfeederporesresultinginmoreefficienttransferofadsorbateintotheadsorptionspace.
Tannin
Tanninsareamixtureoflargeandmediumsizemolecules.Carbonswithacombinationofmacroporesandmesoporesadsorbtannins.Theabilityofacarbontoadsorbtanninsisreportedinpartspermillionconcentration(range200ppm362ppm).
Methyleneblue
Somecarbonshaveamesopore(20to50,or2to5nm)structurewhichadsorbsmediumsizemolecules,suchasthedyemethyleneblue.Methyleneblueadsorptionisreporteding/100g(range1128g/100g).
Dechlorination
Somecarbonsareevaluatedbasedonthedechlorinationhalflifelength,whichmeasuresthechlorineremovalefficiencyofactivatedcarbon.Thedechlorinationhalfvaluelengthisthedepthofcarbonrequiredtoreducethechlorinelevelofaflowingstreamfrom5ppmto3.5ppm.Alowerhalfvaluelengthindicatessuperiorperformance.
Apparentdensity
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Thesolidorskeletaldensityofactivatedcarbonswilltypicallyrangebetween2.0and2.1g/cm3(125130lbs./cubicfoot).However,alargepartofanactivatedcarbonsamplewillconsistofairspacebetweenparticles,andtheactualorapparentdensitywillthereforebelower,typically0.4to0.5g/cm3(2531lbs./cubicfoot).[15]
Higherdensityprovidesgreatervolumeactivityandnormallyindicatesbetterqualityactivatedcarbon.
Hardness/abrasionnumber
Itisameasureoftheactivatedcarbonsresistancetoattrition.Itisanimportantindicatorofactivatedcarbontomaintainitsphysicalintegrityandwithstandfrictionalforcesimposedbybackwashing,etc.Therearelargedifferencesinthehardnessofactivatedcarbons,dependingontherawmaterialandactivitylevel.
Ashcontent
Ashreducestheoverallactivityofactivatedcarbonanditreducestheefficiencyofreactivation.Themetaloxides(Fe2O3)canleachoutofactivatedcarbonresultingindiscoloration.Acid/watersolubleashcontentismoresignificantthantotalashcontent.Solubleashcontentcanbeveryimportantforaquarists,asferricoxidecanpromotealgalgrowths.Acarbonwithalowsolubleashcontentshouldbeusedformarine,freshwaterfishandreeftankstoavoidheavymetalpoisoningandexcessplant/algalgrowth.
Carbontetrachlorideactivity
Measurementoftheporosityofanactivatedcarbonbytheadsorptionofsaturatedcarbontetrachloridevapour.
Particlesizedistribution
Thefinertheparticlesizeofanactivatedcarbon,thebettertheaccesstothesurfaceareaandthefastertherateofadsorptionkinetics.Invapourphasesystemsthisneedstobeconsideredagainstpressuredrop,whichwillaffectenergycost.Carefulconsiderationofparticlesizedistributioncanprovidesignificantoperatingbenefits.
Modificationofpropertiesandreactivity
Acidbase,oxidationreductionandspecificadsorptioncharacteristicsarestronglydependentonthecompositionofthesurfacefunctionalgroups.[16]
Thesurfaceofconventionalactivatedcarbonisreactive,capableofoxidationbyatmosphericoxygenandoxygenplasma[17][18][19][20][21][22][23][24]steam,[25][26][27]andalsocarbondioxide[21]andozone.[28][29][30]
Oxidationintheliquidphaseiscausedbyawiderangeofreagents(HNO3,H2O2,KMnO4),[31][32][33]
Throughtheformationofalargenumberofbasicandacidicgroupsonthesurfaceofoxidizedcarbontosorptionandotherpropertiescandiffersignificantlyfromtheunmodifiedforms.[16]
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Activatedcarboncanbenitrogenatedbynaturalproductsorpolymers[34][35]orprocessingofcarbonwithnitrogenatingreagents.[36][37][38]
Activatedcarboncaninteractwithchlorine,[39][40]bromine[41]andfluorine.[42]
Sulfonicacidfunctionalgroupscanbeattachedtoactivatedcarbontogive"starbons"whichcanbeusedtoselectivelycatalysetheesterificationoffattyacids.[43]Formationofsuchactivatedcarbonsfromhalogenatedprecursorsgivesamoreeffectivecatalystwhichisthoughttobearesultofremaininghalogensimprovingstability.[44]
Someofthechemicalpropertiesofactivatedcarbonhavebeenattributedtopresenceofthesurfaceactivecarbondoublebond.[30][45]
ThePolyaniadsorptiontheoryisapopularmethodforanalyzingadsorptionofvariousorganicsubstancestotheirsurface.
Examplesofadsorption
Heterogeneouscatalysis
Themostcommonlyencounteredformofchemisorptioninindustry,occurswhenasolidcatalystinteractswithagaseousfeedstock,thereactant/s.Theadsorptionofreactant/stothecatalystsurfacecreatesachemicalbond,alteringtheelectrondensityaroundthereactantmoleculeandallowingittoundergoreactionsthatwouldnotnormallybeavailabletoit.
Absorptionrefrigeration
Absorptionrefrigerationandheatpumpcyclesrelyontheadsorptionofarefrigerantgasintoanadsorbentatlowpressureandsubsequentdesorptionbyheating.Theadsorbentactsasa"chemicalcompressor"drivenbyheatandis,fromthispointofview,the"pump"ofthesystem.Itconsistsofasolarcollector,acondenserorheatexchangerandanevaporatorthatisplacedinarefrigeratorbox.Theinsideofthecollectorislinedwithanadsorptionbedpackedwithactivatedcarbonadsorbedwithmethanol.Therefrigeratorboxisinsulatedandfilledwithwater.Theactivatedcarboncanadsorbalargeamountofmethanolvaporsinambienttemperatureanddesorbitatahighertemperature(around100degreesCelsius).Duringthedaytime,thesunshineirradiatesthecollector,sothecollectorisheatedupandthemethanolisdesorbedfromtheactivatedcarbon.Indesorption,theliquidmethanoladsorbedinthecharcoalheatsupandvaporizes.Themethanolvaporcondensesandisstoredintheevaporator.
Atnight,thecollectortemperaturedecreasestotheambienttemperature,andthecharcoaladsorbsthemethanolfromtheevaporator.Theliquidmethanolintheevaporatorvaporizesandabsorbstheheatfromthewatercontainedinthetrays.Sinceadsorptionisaprocessofreleasingheat,thecollectormustbecooledefficientlyatnight.Asmentionedabove,theadsorptionrefrigerationsystemoperatesinanintermittentwaytoproducetherefrigeratingeffect.
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World'slargestreactivationplantlocatedinFeluy,Belgium.
ActivatedcarbonreactivationcenterinRoeselare,Belgium.
Heliumgascanalsobe"pumped"bythermallycyclingactivatedcarbon"sorptionpumps"between4kelvinsandhighertemperatures.AnexampleofthisistoprovidethecoolingpowerfortheOxfordInstrumentsASTseriesdilutionrefrigerators.3Hevaporispumpedfromthesurfaceofthedilutephaseofamixtureofliquid4Heanditsisotope3He.The3Heisadsorbedontothesurfacesofthecarbonatlowtemperature(typically
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Otherregenerationtechniques
Currentconcernswiththehighenergy/costnatureofthermalregenerationofactivatedcarbonhasencouragedresearchintoalternativeregenerationmethodstoreducetheenvironmentalimpactofsuchprocesses.Thoughseveraloftheregenerationtechniquescitedhaveremainedareasofpurelyacademicresearch,somealternativestothermalregenerationsystemshavebeenemployedinindustry.Currentalternativeregenerationmethodsare:
Chemicalandsolventregeneration[50]
Microbialregeneration[51]
Electrochemicalregeneration[52]
Ultrasonicregeneration[53]
Wetairoxidation[54]
Seealso
CarbonblackCarbonfilteringConjugatedmicroporouspolymerKvrnerprocessOnboardrefuelingvaporrecoveryCarbocatalysisHydrogenstorage
References
1. " "PropertiesofActivatedCarbon",CPLCaronLink,accessed20080502"(http://www.activatedcarbon.com/13.html).Retrieved13October2014.
2. "Charcoal,Activated"(http://www.drugs.com/monograph/charcoalactivated.html).TheAmericanSocietyofHealthSystemPharmacists.Retrieved23April2014.
3. ElliottCG,ColbyTV,KellyTM,HicksHG(1989)."Charcoallung.Bronchiolitisobliteransafteraspirationofactivatedcharcoal".Chest96(3):6724.doi:10.1378/chest.96.3.672(https://dx.doi.org/10.1378%2Fchest.96.3.672).PMID2766830(https://www.ncbi.nlm.nih.gov/pubmed/2766830).
4. Sustainablewastewatertreatmentoftemporaryevents:theDranouterMusicFestivalcasestudy(http://www.labmeeting.com/paper/28552316/vanhulle2008sustainablewastewatertreatmentoftemporaryeventsthedranoutermusicfestivalcasestudy).Waterscienceandtechnology:ajournaloftheInternationalAssociationonWaterPollutionResearch.200858(8):16537.
5. "AllianceforCollaborativeResearchinAlternativeFuelTechnology"(http://allcraft.missouri.edu).Allcraft.missouri.edu.Retrieved20140313.
6. Foley,Dennis(2014)."BassAbsorptionWhyThePowerOfDiaphragmaticAbsorptionIsYourOnlyHope"
-
4/15/2015 ActivatedcarbonWikipedia,thefreeencyclopedia
https://en.wikipedia.org/wiki/Activated_carbon 14/17
6. Foley,Dennis(2014)."BassAbsorptionWhyThePowerOfDiaphragmaticAbsorptionIsYourOnlyHope"(http://www.acousticfields.com/bassabsorptionwhythepowerofdiaphragmaticabsorptionisyouronlyhope/).Retrieved20140115.
7. Bourke,Marta(1989)."ActivatedCarbonforMercuryRemoval"(http://www.tigg.com/mercuryremoval.html).Retrieved20130827.
8. TimFlannery,HereOnEarth:ANewBeginning,AllenLane(2011),p.186.9. " ''BMTBegemann,Mercurywastetreatmentfacilities''"(http://www.bmtbegemann.nl/index.html).Bmt
begemann.nl.Retrieved20140313.10. J.Romanosetal.(2012)."NanospaceengineeringofKOHactivatedcarbon".Nanotechnology23(1):015401.
doi:10.1088/09574484/23/1/015401(https://dx.doi.org/10.1088%2F09574484%2F23%2F1%2F015401).11. "WhatIsActivatedCarbon?"(http://www.norit.com/carbonacademy/introduction/).CabotNorit.Retrieved
24October2013.12. ValueAddedProductsfromGasification(http://cgpl.iisc.ernet.in/site/Portals/0/Publications/Presentations/Bio
Energy/Value%20Added%20Products%20From%20Gasification%20%20%20Activated%20Carbon.pdf)ActivatedCarbon,ByShobaJhadhav,TheCombustion,GasificationandPropulsionLaboratory(CGPL)attheIndianInstituteofScience(IISc)
13. Theseparationofthemostvolatilegasesfromairwithoutliquefaction14. "SentryAir"(http://www.sentryair.com/activatedcarbonfilter.htm).SentryAir.Retrieved20140313.15. TIGGCorporation.Granularactivatedcarbonselection(http://www.tigg.com/granularactivated
carbon.html#AnchorApparen32986).Published2012058,retrieved20120921.16. PhilippeSerp,JosLuisFigueiredo,CarbonMaterialsforCatalysis,Wiley,2009,550p.17. GmezSerrano,V.PirizAlmeida,F.N.DurnValle,C.J.PastorVillegas,J.(1999)."Formationofoxygen
structuresbyairactivation.AstudybyFTIRspectroscopy".Carbon37(10):1517.doi:10.1016/S00086223(99)000251(https://dx.doi.org/10.1016%2FS00086223%2899%29000251).
18. MachnikowskiJ.,KaczmarskaH.,GerusPiaseckaI.,DiezM.A.,AlvarezR.,GarciaR.Structuralmodificationofcoaltarpitchfractionsduringmildoxidationrelevancetocarbonizationbehavior//Carbon.2002.V.40.P.19371947
19. PetrovN.,BudinovaT.,RazvigorovaM.,EkinciE.,YardimF.,MinkovaV.Preparationandcharacterizationofcarbonadsorbentsfromfurfural//Carbon2000.V.38,15.P.20692075
20. GarciaA.B.,MartinezAlonsoA.,LeonC.A.,TasconJ.M.D.Modificationofthesurfacepropertiesofanactivatedcarbonbyoxygenplasmatreatment//Fuel.1998.V.77,1P.613624
21. SahaB.,TaiM.H.,StreatM.Studyofactivatedcarbonafteroxidationandsubsequenttreatmentcharacterization//Processsafetyandenvironmentalprotection2001.V.79,B4.P.211217
22. PolovinaM.,BabicB.,KaluderovicB.,DekanskiA.Surfacecharacterizationofoxidizedactivatedcarboncloth//Carbon1997.V.35,8.P.10471052
23. FanningP.E.,VanniceM.A.ADRIFTSstudyoftheformationofsurfacegroupsoncarbonbyoxidation//Carbon1993.V.31,5.P.721730
24. YoussefA.M.,AbdelbaryE.M.,SamraS.E.,DowidarA.M.Surfacepropertiesofcarbonsobtainedfrompolyvinylchloride//Ind.J.ofChem.sectionainorganicbioinorganicphysicaltheoretical&analyticalchemistry1991.V.30,10.P.839843
25. ArriagadaR.,GarciaR.,MolinaSabioM.,RodriguezReinosoF.EffectofsteamactivationontheporosityandchemicalnatureofactivatedcarbonsfromEucalyptusglobulusandpeachstones//MicroporousMat.1997.V.8,34.P.123130
-
4/15/2015 ActivatedcarbonWikipedia,thefreeencyclopedia
https://en.wikipedia.org/wiki/Activated_carbon 15/17
V.8,34.P.12313026. MolinaSabioM.,GonzalezM.T.,RodriguezReinosoF.,SepulvedaEscribanoA.Effectofsteamandcarbon
dioxideactivationinthemicroporesizedistributionofactivatedcarbon//Carbon1996.V.34,4.P.505509
27. BradleyRH,SutherlandI,ShengECarbonsurface:Area,porosity,chemistry,andenergy//J.ofcolloidandinterfacescience1996.V.179,2.P.561569
28. SutherlandI.,ShengE.,BraleyR.H.,FreakleyP.K.Effectsofozoneoxidationoncarbonblacksurfaces//J.Mater.Sci.1996.V.31.P.56515655
29. RiveraUtrillaJSanchezPoloM.Theroleofdispersiveandelectrostaticinteractionsintheaqueousphaseadsorptionofnaphthalenesulphonicacidsonozonetreatedactivatedcarbons//Carbon2002.V.40,14.P.26852691
30. Valds,H.SnchezPolo,M.RiveraUtrilla,J.Zaror,C.A.(2002)."EffectofOzoneTreatmentonSurfacePropertiesofActivatedCarbon".Langmuir18(6):2111.doi:10.1021/la010920a(https://dx.doi.org/10.1021%2Fla010920a).
31. PradhanB.K.,SandleN.K.Effectofdifferentoxidizingagenttreatmentsonthesurfacepropertiesofactivatedcarbons//Carbon.1999.V.37,8.P.13231332
32. AcedoRamosM.,GomezSerranoV.,ValenzuellaCalahorroC.,andLopezPeinadoA.J.Oxydationofactivatedcarboninliquidphase.StudybyFTIR//Spectroscopyletters.1993.V26(6).P.11171137
33. GomezSerranoV.,AcedoRamosM.,LopezPeinadoA.J.,ValenzuelaCalahorroC.Stabilitytowardsheatingandoutgassingofactivatedcarbonoxidizedintheliquidphase//ThermochimicaActa.1991.V.176.P.129140
34. SthrB.,BoehmH.P.,SchlglR.Enhancementofthecatalyticactivitiofactivatedcarbonsinoxidationreactionsbytermaltreatmentwithammoniaorhydrogencyanideandobservationofasuperoxidespeciesasapossibleintermediate//Carbon.1991.Vol.26,6.P.707720
35. BiniakS.,SzymaskiG.,SiedlewskiJ.,wiatkowskiA.Thecharacterizaionofactivatedcarbonswithoxygenandnitrogensurfacegroups//Carbn.1997.Vol.35,12.P.17991810
36. BoudouJ.P.,ChehimiM.,BroniekE.,SiemieniewskaT.,BimerJ.AdsorptionofH2SorSO2onanactivatedcarbonclothmodifiedbyammoniatreatment//Carbon.2003.Vol.41,10.P.19992007
37. SanoH.,OgawaH.Preparationandapplicationnitrogencontainingactivecarbons//OsakaKogyoGijutsuShirenjo.1975.Vol.26,5.P.20842086
38. Radkevich,V.Z.Senko,T.L.Wilson,K.Grishenko,L.M.Zaderko,A.N.Diyuk,V.Y.(2008)."Theinfluenceofsurfacefunctionalizationofactivatedcarbononpalladiumdispersionandcatalyticactivityinhydrogenoxidation".AppliedCatalysisA:General335(2):241.doi:10.1016/j.apcata.2007.11.029(https://dx.doi.org/10.1016%2Fj.apcata.2007.11.029).
39. Evans,M.J.B.Halliop,E.Liang,S.MacDonald,J.A.F.(1998)."Theeffectofchlorinationonsurfacepropertiesofactivatedcarbon".Carbon36(11):1677.doi:10.1016/S00086223(98)001651(https://dx.doi.org/10.1016%2FS00086223%2898%29001651).
40. Papirer,E.N.Lacroix,R.Donnet,J.B.Nans,G.R.Fioux,P.(1995)."XPSstudyofthehalogenationofcarbonblackPart2.Chlorination".Carbon33:63.doi:10.1016/00086223(94)00111C(https://dx.doi.org/10.1016%2F00086223%2894%2900111C).
41. ScienceDirect.comCarbonXPSStudyofthehalogenationofcarbonblackpart1.Bromination(http://www.sciencedirect.com/science/article/pii/000862239490121X)
-
4/15/2015 ActivatedcarbonWikipedia,thefreeencyclopedia
https://en.wikipedia.org/wiki/Activated_carbon 16/17
42. Nans,G.Papirer,E.Fioux,P.Moguet,F.Tressaud,A.(1997)."Fluorinationofcarbonblacks:AnXrayphotoelectronspectroscopystudy:III.Fluorinationofdifferentcarbonblackswithgaseousfluorineattemperaturesbelow100Cinfluenceofthemorphology,structureandphysicochemicalcharacteristicsofthecarbonblackonthefluorinefixation".Carbon35(4):515.doi:10.1016/S00086223(97)000031(https://dx.doi.org/10.1016%2FS00086223%2897%29000031).
43. AldanaPrez,A.LartundoRojas,L.Gmez,R.NioGmez,M.E.(2012)."SulfonicgroupsanchoredonmesoporouscarbonStarbons300anditsusefortheesterificationofoleicacid".Fuel100:128.doi:10.1016/j.fuel.2012.02.025(https://dx.doi.org/10.1016%2Fj.fuel.2012.02.025).
44. Diyuk,V.E.Zaderko,A.N.Grishchenko,L.M.Yatsymyrskiy,A.V.Lisnyak,V.V.(2012)."Efficientcarbonbasedacidcatalystsforthepropan2oldehydration".CatalysisCommunications27:33.doi:10.1016/j.catcom.2012.06.018(https://dx.doi.org/10.1016%2Fj.catcom.2012.06.018).
45. Budarin,V.L.Clark,J.H.Tavener,S.J.Wilson,K.(2004)."Chemicalreactionsofdoublebondsinactivatedcarbon:Microwaveandbrominationmethods".ChemicalCommunications(23):2736.doi:10.1039/B411222A(https://dx.doi.org/10.1039%2FB411222A).
46. Bagreev,A.Rhaman,H.Bandosz,T.J(2001)."Thermalregenerationofaspentactivatedcarbonadsorbentpreviouslyusedashydrogensulfideadsorbent".Carbon39(9):13191326.doi:10.1016/S00086223(00)002669(https://dx.doi.org/10.1016%2FS00086223%2800%29002669).
47. Sabio,E.Gonzalez,E.Gonzalez,J.F.GonzalezGarcia,C.M.Ramiro,A.Ganan,J(2004)."Thermalregenerationofactivatedcarbonsaturatedwithpnitrophenol".Carbon42(11):22852293.doi:10.1016/j.carbon.2004.05.007(https://dx.doi.org/10.1016%2Fj.carbon.2004.05.007).
48. MiguelGS,LambertSD,GrahamNJ(2001)."Theregenerationoffieldspentgranularactivatedcarbons".WaterResearch35(11):27402748.doi:10.1016/S00431354(00)005492(https://dx.doi.org/10.1016%2FS00431354%2800%29005492).PMID11456174(https://www.ncbi.nlm.nih.gov/pubmed/11456174).
49. AlvarezPM,BeltrnFJ,GmezSerranoV,JaramilloJ,RodrguezEM(2004)."Comparisonbetweenthermalandozoneregenerationsofspentactivatedcarbonexhaustedwithphenol".WaterResearch38(8):21552165.doi:10.1016/j.watres.2004.01.030(https://dx.doi.org/10.1016%2Fj.watres.2004.01.030).PMID15087197(https://www.ncbi.nlm.nih.gov/pubmed/15087197).
50. Martin,R.J.Wj,N(1997)."Therepeatedexhaustionandchemicalregenerationofactivatedcarbon".WaterResearch21(8):961965.doi:10.1016/S00431354(87)800143(https://dx.doi.org/10.1016%2FS00431354%2887%29800143).
51. AizpuruA,MalhautierL,RouxJC,FanloJL(2003)."Biofiltrationofamixtureofvolatileorganiccompoundsongranularactivatedcarbon".BiotechnologyandBioengineering83(4):479488.doi:10.1002/bit.10691(https://dx.doi.org/10.1002%2Fbit.10691).PMID12800142(https://www.ncbi.nlm.nih.gov/pubmed/12800142).
52. NarbaitzRM,KarimiJashniA(2009)."Electrochemicalregenerationofgranularactivatedcarbonsloadedwithphenolandnaturalorganicmatter".EnvironmentalTechnology30(1):2736.doi:10.1080/09593330802422803(https://dx.doi.org/10.1080%2F09593330802422803).PMID19213463(https://www.ncbi.nlm.nih.gov/pubmed/19213463).
53. LimJL,OkadaM(2005)."Regenerationofgranularactivatedcarbonusingultrasound".UltrasonicSonoChemistry12(4):277285.doi:10.1016/j.ultsonch.2004.02.003(https://dx.doi.org/10.1016%2Fj.ultsonch.2004.02.003).PMID15501710(https://www.ncbi.nlm.nih.gov/pubmed/15501710).
54. ShendeRV,MahajaniVV(2002)."Wetoxidativeregenerationofactivatedcarbonloadedwithreactivedye".
-
4/15/2015 ActivatedcarbonWikipedia,thefreeencyclopedia
https://en.wikipedia.org/wiki/Activated_carbon 17/17
Externallinks
"Imagingtheatomicstructureofactivatedcarbon"(http://www.personal.rdg.ac.uk/~scsharip/Activated_carbon_JPCM.pdf)JOURNALOFPHYSICS:CONDENSEDMATTEREngber,Daniel(Nov.28,2005)."HowDoesActivatedCarbonWork?"(http://www.slate.com/id/2131130/).Slate.
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54. ShendeRV,MahajaniVV(2002)."Wetoxidativeregenerationofactivatedcarbonloadedwithreactivedye".WasteManagement22(1):7383.doi:10.1016/S0956053X(01)000228(https://dx.doi.org/10.1016%2FS0956053X%2801%29000228).PMID11942707(https://www.ncbi.nlm.nih.gov/pubmed/11942707).