Kunna carbon (AC) yana nufin sosai carbonaceous kayan da ciwon high porosity da sorption ikon samar daga itace, kwakwa bawo, kwal, da Cones, da dai sauransu AC yana daya daga cikin akai-akai amfani adsorbents amfani a daban-daban masana'antu domin kau da yawa pollutants. daga jikin ruwa da iska.Tunda, AC ta haɗe daga kayan noma da sharar gida, ya zama babban madadin hanyoyin da ba a sabunta su ba kuma masu tsada a al'adance.Don shirye-shiryen AC, ana amfani da matakai guda biyu na asali, carbonization da kunnawa.A cikin tsari na farko, abubuwan da suka riga sun kasance suna fuskantar matsanancin zafi, tsakanin 400 zuwa 850 ° C, don fitar da duk abubuwan da ba su da ƙarfi.Maɗaukakin zafin jiki yana kawar da duk abubuwan da ba na carbon ba daga abubuwan da ke gaba kamar hydrogen, oxygen, da nitrogen a cikin sigar gas da tars.Wannan tsari yana samar da char mai yawan abun ciki na carbon amma ƙarancin fili da porosity.Koyaya, mataki na biyu ya ƙunshi kunna char da aka haɗa a baya.Za'a iya rarraba girman girman pore yayin aiwatar da kunnawa zuwa uku: buɗe faɗuwar ramukan da ba za a iya isa ba a baya, sabon haɓakar ramuka ta hanyar kunna zaɓi, da faɗaɗa ramukan da ke akwai.
Yawancin lokaci, ana amfani da hanyoyi guda biyu, na jiki da na sinadarai, don kunnawa don samun filin da ake so da porosity.Kunna jiki ya ƙunshi kunna carbonized char ta hanyar amfani da iskar gas kamar iska, carbon dioxide, da tururi a matsanancin zafi (tsakanin 650 da 900°C).Carbon dioxide yawanci ana fifita shi saboda tsaftar yanayin sa, sauƙin sarrafa shi, da tsarin kunnawa mai sarrafawa a kusa da 800°C.Za'a iya samun daidaito mai girma tare da kunna carbon dioxide idan aka kwatanta da tururi.Koyaya, don kunnawa ta jiki, an fi son tururi sosai idan aka kwatanta da carbon dioxide tunda ana iya samar da AC tare da babban yanki mai tsayi.Saboda ƙarami girman ruwa, yaduwarsa a cikin tsarin char yana faruwa da kyau.An gano kunnawa ta tururi kusan sau biyu zuwa uku sama da carbon dioxide tare da juzu'i iri ɗaya.
Koyaya, tsarin sinadarai ya haɗa da haɗakar precursor tare da wakilai masu kunnawa (NaOH, KOH, da FeCl3, da sauransu).Wadannan abubuwan da ke kunnawa suna aiki azaman oxidants da kuma dehydrating wakilai.A cikin wannan hanyar, carbonization da kunnawa ana aiwatar da su a lokaci guda a daidai yanayin zafin jiki na 300-500 ° C idan aka kwatanta da tsarin jiki.A sakamakon haka, yana haifar da bazuwar pyrolytic kuma, sa'an nan, yana haifar da faɗaɗa ingantaccen tsari mai ƙarfi da yawan amfanin carbon.Manyan fa'idodin sinadarai akan tsarin jiki sune ƙarancin buƙatun zafin jiki, manyan sifofin microporosity, babban yanki, da ƙarancin lokacin kammala amsawa.
Za'a iya bayyana fifikon hanyar kunna sinadarai bisa tsarin ƙirar Kim da abokan aikinsa [1] bisa ga abin da microdomains daban-daban masu kewaye da ke da alhakin samuwar micropores ana samun su a cikin AC.A gefe guda, ana haɓaka mesopores a cikin yankuna na intermicrodomain.Gwaji, sun samar da carbon da aka kunna daga resin tushen phenol ta hanyar sinadarai (ta amfani da KOH) da na jiki (ta amfani da tururi) kunnawa (Hoto 1).Sakamakon ya nuna cewa AC ɗin da aka haɗa ta KOH kunnawa yana da babban yanki na 2878 m2/g idan aka kwatanta da 2213 m2/g ta hanyar kunna tururi.Bugu da ƙari, wasu dalilai irin su girman pore, yanki na sararin samaniya, ƙarar micropore, da matsakaicin matsakaicin pore duk an samo su mafi kyau a cikin yanayin da aka kunna KOH idan aka kwatanta da kunna tururi.
Bambance-bambance tsakanin AC An shirya daga kunnawar tururi (C6S9) da kunna KOH (C6K9), bi da bi, an bayyana shi cikin tsarin ƙirar microstructure.
Ya danganta da girman barbashi da hanyar shiri, ana iya kasasa shi zuwa nau'ikan uku: AC mai ƙarfi, granular AC, da AC mai ƙarfi.AC mai ƙarfi yana samuwa daga granules masu kyau masu girman 1 mm tare da matsakaicin diamita na 0.15-0.25 mm.Granular AC yana da girman girman kwatankwacinsa da ƙasan fili na waje.Ana amfani da granular AC don aikace-aikacen lokaci na ruwa daban-daban da aikace-aikacen lokaci na gaseous dangane da girman girman su.Aji na uku: Bead AC gabaɗaya ana haɗa shi daga filin mai tare da diamita daga 0.35 zuwa 0.8 mm.An san shi don ƙarfin ƙarfin injinsa da ƙananan ƙura.Ana amfani da shi sosai a aikace-aikacen gado na ruwa kamar tace ruwa saboda tsarin sa.
Lokacin aikawa: Juni-18-2022