Kaboni yogwira ntchito (AC) imatanthauza zinthu zomwe zimakhala ndi mpweya wambiri zomwe zimakhala ndi porosity komanso mphamvu yosungunula zomwe zimapangidwa kuchokera ku matabwa, zipolopolo za kokonati, malasha, ndi ma cones, ndi zina zotero. AC ndi imodzi mwa zinthu zomwe zimagwiritsidwa ntchito nthawi zambiri m'mafakitale osiyanasiyana pochotsa zinthu zambiri zoipitsa m'madzi ndi mlengalenga. Popeza AC yopangidwa kuchokera ku zinthu zaulimi ndi zinyalala, yakhala njira yabwino kwambiri m'malo mwa zinthu zomwe zimagwiritsidwa ntchito mwachizolowezi zosabwezeretsedwanso komanso zodula. Pokonzekera AC, njira ziwiri zazikulu, carbonization ndi activation, zimagwiritsidwa ntchito. Mu njira yoyamba, zinthu zoyambira zimayikidwa kutentha kwambiri, pakati pa 400 ndi 850°C, kuti zichotse zinthu zonse zosinthasintha. Kutentha kwakukulu kumachotsa zinthu zonse zopanda mpweya kuchokera ku zinthu zoyambira monga hydrogen, oxygen, ndi nayitrogeni mu mawonekedwe a mpweya ndi ma tar. Njirayi imapanga char yokhala ndi mpweya wambiri koma malo otsika komanso porosity. Komabe, gawo lachiwiri limaphatikizapo kuyambitsa char yomwe idapangidwa kale. Kukula kwa ma pores panthawi yoyambitsa ma pores kungagawidwe m'magulu atatu: kutseguka kwa ma pores omwe kale anali osafikirika, kupangidwa kwa ma pores atsopano mwa kuyambitsa kosankha, ndi kukulira kwa ma pores omwe alipo.
Kawirikawiri, njira ziwiri, zakuthupi ndi zamankhwala, zimagwiritsidwa ntchito poyambitsa kuti pakhale malo ofunikira pamwamba ndi porosity. Kuyambitsa thupi kumaphatikizapo kuyambitsa mpweya wa carbonized char pogwiritsa ntchito mpweya wowonjezera monga mpweya, carbon dioxide, ndi nthunzi kutentha kwambiri (pakati pa 650 ndi 900°C). Carbon dioxide nthawi zambiri imakondedwa chifukwa cha chilengedwe chake choyera, kusavuta kuigwiritsa ntchito, komanso njira yowongolera yoyambitsa pafupifupi 800°C. Kufanana kwa ma pore ambiri kumatha kupezeka poyambitsa carbon dioxide poyerekeza ndi nthunzi. Komabe, poyambitsa thupi, nthunzi imakondedwa kwambiri poyerekeza ndi carbon dioxide popeza AC yokhala ndi malo okwera imatha kupangidwa. Chifukwa cha kukula kochepa kwa mamolekyulu a madzi, kufalikira kwake mkati mwa kapangidwe ka char kumachitika bwino. Kuyambitsa ndi nthunzi kwapezeka kuti kuli kokwera kawiri kapena katatu kuposa carbon dioxide yokhala ndi kusintha komweko.
Komabe, njira ya mankhwala imaphatikizapo kusakaniza zinthu zoyambira ndi zinthu zoyambitsa (NaOH, KOH, ndi FeCl3, ndi zina zotero). Zinthu zoyambitsa izi zimagwira ntchito ngati ma oxidant komanso zinthu zochotsa madzi m'thupi. Mu njira iyi, carbonization ndi activation zimachitika nthawi imodzi pa kutentha kotsika kwa 300-500°C poyerekeza ndi njira ya thupi. Zotsatira zake, zimakhudza kuwonongeka kwa pyrolytic ndipo, kenako, zimapangitsa kuti kapangidwe kake kakhale kokongola komanso kutulutsa mpweya wambiri. Ubwino waukulu wa njira ya mankhwala kuposa ya thupi ndi kufunikira kwa kutentha kochepa, kapangidwe ka microporosity kambiri, malo akuluakulu, komanso nthawi yochepa yomaliza kuchitapo kanthu.
Kupambana kwa njira yogwiritsira ntchito mankhwala kungafotokozedwe potengera chitsanzo chomwe Kim ndi anzake ogwira nawo ntchito adapereka [1] malinga ndi momwe ma microdomain osiyanasiyana ozungulira omwe amachititsa kupanga ma micropores amapezeka mu AC. Kumbali ina, ma mesopores amapangidwa m'madera a intermicrodomain. Mwa kuyesa, adapanga activated carbon kuchokera ku phenol-based resin pogwiritsa ntchito mankhwala (pogwiritsa ntchito KOH) ndi physical (pogwiritsa ntchito nthunzi) activation (Chithunzi 1). Zotsatira zake zidawonetsa kuti AC yopangidwa ndi KOH activation inali ndi malo okwera a 2878 m2/g poyerekeza ndi 2213 m2/g pogwiritsa ntchito nthunzi. Kuphatikiza apo, zinthu zina monga kukula kwa ma pore, malo a pamwamba, kuchuluka kwa ma micropores, ndi m'lifupi mwa ma pore onse adapezeka kuti ndi abwino kwambiri m'mikhalidwe yogwiritsidwa ntchito ndi KOH poyerekeza ndi nthunzi.
Kusiyana pakati pa AC Yokonzedwa kuchokera ku kuyatsa kwa nthunzi (C6S9) ndi kuyatsa kwa KOH (C6K9), motsatana, yafotokozedwa motsatira chitsanzo cha kapangidwe ka microstructure.
Kutengera kukula kwa tinthu ndi njira yokonzekera, ikhoza kugawidwa m'magulu atatu: AC yoyendetsedwa ndi magetsi, AC yophwanyika, ndi AC yophwanyika. AC yoyendetsedwa ndi magetsi imapangidwa kuchokera ku tinthu tating'onoting'ono tomwe tili ndi kukula kwa 1 mm ndi mulifupi wapakati wa 0.15-0.25 mm. AC yophwanyika ndi yayikulu poyerekeza ndi malo akunja. AC yophwanyika imagwiritsidwa ntchito pazinthu zosiyanasiyana zamadzimadzi ndi gasi kutengera kuchuluka kwa miyeso yawo. Gulu lachitatu: AC yophwanyika nthawi zambiri imapangidwa kuchokera ku mafuta okhala ndi mulifupi kuyambira 0.35 mpaka 0.8 mm. Imadziwika ndi mphamvu zake zambiri zamakaniko komanso fumbi lochepa. Imagwiritsidwa ntchito kwambiri pogwiritsira ntchito madzi monga kusefa madzi chifukwa cha kapangidwe kake kozungulira.
Nthawi yotumizira: Juni-18-2022