I-activated carbon (AC) ibhekisela ezintweni eziqukethe i-carbonaceous enamandla kakhulu ezine-porosity ephezulu kanye nekhono lokumunca elikhiqizwa ngokhuni, amagobolondo kakhukhunathi, amalahle, nama-cones, njll. I-AC ingenye yezithako ezisetshenziswa njalo ezisetshenziswa ezimbonini ezahlukene ukususa ukungcola okuningi emanzini nasemoyeni. Njengoba i-AC yenziwe ngemikhiqizo yezolimo kanye nemfucuza, iye yaba yindlela enhle kakhulu kunemithombo engasetshenziswa kabusha futhi ebizayo esetshenziswa ngokwesiko. Ukulungiselela i-AC, kusetshenziswa izinqubo ezimbili eziyisisekelo, i-carbonization kanye nokusebenza kwayo. Enqubweni yokuqala, izinto ezisetshenziswayo zifakwa emazingeni okushisa aphezulu, phakathi kuka-400 no-850°C, ukuze kukhishwe zonke izingxenye eziguquguqukayo. Izinga lokushisa eliphakeme lisusa zonke izingxenye ezingezona i-carbon ku-precursor njenge-hydrogen, i-oxygen, kanye ne-nitrogen ngesimo samagesi nama-tar. Le nqubo ikhiqiza i-char enokuqukethwe kwe-carbon ephezulu kodwa indawo ephansi kanye ne-porosity. Kodwa-ke, isinyathelo sesibili sihilela ukusebenza kwe-char eyenziwe ngaphambilini. Ukuthuthukiswa kosayizi wembobo ngesikhathi senqubo yokuvuselela kungahlukaniswa ngezigaba ezintathu: ukuvulwa kwembobo ezazingafinyeleleki ngaphambili, ukuthuthukiswa kwembobo entsha ngokusebenza okukhethiwe, kanye nokwandiswa kwembobo ezikhona.
Ngokuvamile, kusetshenziswa izindlela ezimbili, ezingokoqobo nezamakhemikhali, ukuze kusebenze ukuze kutholakale indawo efiselekayo kanye nokuvuleka. Ukusebenza ngokomzimba kuhilela ukusebenza kwe-char ekhabhoni kusetshenziswa amagesi akhipha i-oxidation njengomoya, i-carbon dioxide, kanye ne-steam emazingeni okushisa aphezulu (phakathi kuka-650 no-900°C). I-Carbon dioxide ivame ukuthandwa ngenxa yemvelo yayo emsulwa, ukuphathwa okulula, kanye nenqubo yokusebenza elawulwayo engaba ngu-800°C. Ukufana kwe-pore ephezulu kungatholakala ngokusebenzisa i-carbon dioxide uma kuqhathaniswa ne-steam. Kodwa-ke, ukuze kusebenze ngokomzimba, i-steam ithandwa kakhulu uma kuqhathaniswa ne-carbon dioxide njengoba i-AC enendawo ephezulu ingakhiqizwa. Ngenxa yobukhulu bamanzi obuncane bama-molecule, ukusabalala kwayo ngaphakathi kwesakhiwo se-char kwenzeka kahle. Ukusebenza nge-steam kutholakale ukuthi kuphakeme ngokuphindwe kabili kuya kathathu kune-carbon dioxide enezinga elifanayo lokuguqulwa.
Kodwa-ke, indlela yamakhemikhali ihilela ukuxubana kwezinto ezibangela ukuvuvukala nama-activation agents (NaOH, KOH, kanye ne-FeCl3, njll.). La ma-activation agents asebenza njengama-oxidants kanye nama-dehydrating agents. Kule ndlela, i-carbonization kanye ne-activation yenziwa ngesikhathi esisodwa ekushiseni okuphansi okungu-300-500°C uma kuqhathaniswa nendlela ebonakalayo. Ngenxa yalokho, kuthinta ukubola kwe-pyrolytic bese, kuphumela ekwandiseni isakhiwo esithuthukisiwe se-porous kanye ne-carbon vield ephezulu. Izinzuzo ezinkulu zendlela yamakhemikhali ngaphezu kweyomzimba yisidingo sokushisa okuphansi, izakhiwo eziphezulu ze-microporosity, indawo enkulu, kanye nesikhathi esincishisiwe sokuqeda ukusabela.
Ukuphakama kwendlela yokwenza kusebenze amakhemikhali kungachazwa ngesisekelo semodeli ephakanyiswe nguKim kanye nozakwabo [1] lapho kutholakala khona ama-microdomain ahlukahlukene ayindilinga abhekene nokwakheka kwama-micropores ku-AC. Ngakolunye uhlangothi, ama-mesopores athuthukiswa ezifundeni ze-intermicrodomain. Ngokuhlola, akha i-activated carbon kusuka ku-phenol-based resin ngamakhemikhali (kusetshenziswa i-KOH) kanye nokusebenza ngokomzimba (kusetshenziswa umusi) (Isithombe 1). Imiphumela ibonise ukuthi i-AC eyenziwe nge-KOH activation yayinendawo ephezulu engu-2878 m2/g uma kuqhathaniswa no-2213 m2/g ngokusebenza komusi. Ngaphezu kwalokho, ezinye izici ezifana nosayizi we-pore, indawo yobuso, ivolumu ye-micropore, kanye nobubanzi be-pore obujwayelekile konke kutholakale kungcono ezimweni ezisebenza nge-KOH uma kuqhathaniswa nokusebenza komusi.
Umehluko phakathi kwe-AC Kulungiselelwe kusukela ekusebenzeni komusi (C6S9) kanye nokusebenza kwe-KOH (C6K9), ngokulandelana, kuchazwe ngokwemodeli yesakhiwo esincane.
Kuye ngobukhulu bezinhlayiya kanye nendlela yokulungiselela, ingahlukaniswa ngezinhlobo ezintathu: i-AC enamandla, i-AC enezinhlayiya, kanye ne-AC enezinhlayiya. I-AC enamandla yakhiwa ngama-granule amancane anosayizi ongu-1 mm nobubanzi obumaphakathi obungu-0.15-0.25 mm. I-AC enezinhlayiya inobukhulu obukhulu kakhulu kanye nendawo encane yangaphandle. I-AC enezinhlayiya isetshenziselwa izinhlelo ezahlukene zesigaba soketshezi kanye nesigaba segesi kuye ngokuthi zingakanani ubukhulu bazo. Isigaba sesithathu: i-AC enezinhlayiya ngokuvamile ikhiqizwa kusuka ku-petroleum pitch enobubanzi obusukela ku-0.35 kuya ku-0.8 mm. Yaziwa ngamandla ayo aphezulu okusebenza kanye nokuqukethwe okuphansi kothuli. Isetshenziswa kakhulu ekusetshenzisweni kombhede oketshezi njengokuhlunga amanzi ngenxa yesakhiwo sayo esiyindilinga.
Isikhathi sokuthunyelwe: Juni-18-2022