Cellulose, polima wachilengedwe wochuluka kwambiri padziko lonse lapansi, amapanga gawo lalikulu la biomass ndi zipangizo zosiyanasiyana zamafakitale. Kukhazikika kwake kodabwitsa kumabweretsa zovuta pakuwonongeka kwake bwino, kofunikira kwambiri pakugwiritsa ntchito monga kupanga biofuel ndi kasamalidwe ka zinyalala. Hydrogen peroxide (H2O2) yakhala ngati njira yotha kusungunuka kwa cellulose chifukwa cha chilengedwe chake chosawononga chilengedwe komanso mphamvu zake zopangitsa kuti zinthu ziwonongeke.
Chiyambi:
Cellulose, polysaccharide yopangidwa ndi mayunitsi a shuga olumikizidwa ndi ma bond a β-1,4-glycosidic, ndi gawo lalikulu la kapangidwe ka makoma a maselo a zomera. Kuchuluka kwake mu biomass kumapangitsa kuti ikhale chuma chokongola m'mafakitale osiyanasiyana, kuphatikizapo mapepala ndi zamkati, nsalu, ndi bioenergy. Komabe, netiweki yolimba ya hydrogen bonding mkati mwa cellulose fibrils imapangitsa kuti isasungunuke m'zinthu zambiri zosungunulira, zomwe zimapangitsa kuti zikhale zovuta kugwiritsa ntchito bwino komanso kubwezeretsanso zinthu.
Njira zachikhalidwe zosungunula cellulose zimaphatikizapo zinthu zovuta, monga ma acid ochulukirapo kapena madzi a ionic, omwe nthawi zambiri amagwirizanitsidwa ndi nkhawa zachilengedwe komanso kugwiritsa ntchito mphamvu zambiri. Mosiyana ndi zimenezi, hydrogen peroxide imapereka njira ina yabwino chifukwa cha kusowa kwake okosijeni komanso kuthekera kokonza cellulose mosawononga chilengedwe. Pepalali likufotokoza njira zomwe zimapangitsa kuti cellulose isungunuke pogwiritsa ntchito hydrogen peroxide ndikuwunika momwe imagwirira ntchito komanso momwe imagwiritsidwira ntchito.
Njira Zosungunula Cellulose ndi Hydrogen Peroxide:
Kusungunuka kwa cellulose ndi hydrogen peroxide kumaphatikizapo zochitika zovuta za mankhwala, makamaka kugawanika kwa okosijeni kwa ma glycosidic bonds ndi kusokonezeka kwa ma hydrogen bond pakati pa mamolekyulu. Njirayi nthawi zambiri imachitika motere:
Kusungunuka kwa Magulu a Hydroxyl: Hydrogen peroxide imayanjana ndi magulu a hydroxyl a cellulose, zomwe zimapangitsa kuti ma hydroxyl radicals (•OH) apangidwe kudzera mu Fenton kapena Fenton-like reactions pamaso pa ma transition metal ions. Ma radical awa amaukira ma glycosidic bonds, kuyambitsa kusweka kwa unyolo ndikupanga zidutswa zazifupi za cellulose.
Kusokonezeka kwa Kugwirizana kwa Hydrogen: Ma hydroxyl radicals amasokonezanso netiweki yolumikizana kwa hydrogen pakati pa unyolo wa cellulose, kufooketsa kapangidwe kake konsekonse ndikuthandiza kuthetsedwa.
Kupanga Zotumphukira Zosungunuka: Kuwonongeka kwa okosijeni kwa cellulose kumapangitsa kuti pakhale zinthu zosungunuka m'madzi monga carboxylic acid, aldehydes, ndi ketones. Zotumphukira izi zimathandiza kuti zinthu zisungunuke mwa kuwonjezera kusungunuka ndi kuchepetsa kukhuthala.
Kuchotsa upolima ndi Kugawikana: Kuwonjezeka kwa okosijeni ndi kugawikana kwa zinthu kumapangitsa kuti unyolo wa cellulose usakhale wofanana ndi ma oligomer afupiafupi ndipo pamapeto pake umakhala shuga wosungunuka kapena zinthu zina zolemera pang'ono.
Zinthu Zomwe Zimakhudza Kusungunuka kwa Cellulose Yothandizidwa ndi Hydrogen Peroxide:
Kugwira ntchito bwino kwa kusungunuka kwa cellulose pogwiritsa ntchito hydrogen peroxide kumakhudzidwa ndi zinthu zosiyanasiyana, kuphatikizapo:
Kuchuluka kwa Hydrogen Peroxide: Kuchuluka kwa hydrogen peroxide nthawi zambiri kumabweretsa kuchuluka kwa zochita mwachangu komanso kuwonongeka kwakukulu kwa cellulose. Komabe, kuchuluka kwambiri kungayambitse zotsatira zoyipa kapena zinthu zina zosafunikira.
pH ndi Kutentha: pH ya reaction medium imakhudza kupanga ma hydroxyl radicals ndi kukhazikika kwa ma cellulose derivatives. Nthawi zambiri acidity yocheperako (pH 3-5) imakondedwa kuti iwonjezere kusungunuka kwa cellulose popanda kuwonongeka kwakukulu. Kuphatikiza apo, kutentha kumakhudza reaction kinetics, ndipo kutentha kwakukulu nthawi zambiri kumathandizira kusungunuka kwa madzi.
Kupezeka kwa Ma Catalysts: Ma ayoni achitsulo osinthika, monga chitsulo kapena mkuwa, amatha kuyambitsa kuwonongeka kwa hydrogen peroxide ndikuwonjezera mapangidwe a hydroxyl radicals. Komabe, kusankha catalyst ndi kuchuluka kwake kuyenera kukonzedwa mosamala kuti kuchepetse zotsatira zoyipa ndikuwonetsetsa kuti zinthu zili bwino.
Kapangidwe ka Cellulose ndi Crystallinity: Kupezeka kwa unyolo wa cellulose ku hydrogen peroxide ndi hydroxyl radicals kumakhudzidwa ndi mawonekedwe a zinthuzo ndi kapangidwe ka crystalline. Madera a amorphous ndi omwe amatha kuwonongeka mosavuta kuposa madera a crystalline kwambiri, zomwe zimapangitsa kuti pakhale njira zochizira kapena kusintha kuti ziwongolere kupezeka.
Ubwino ndi Kugwiritsa Ntchito kwa Hydrogen Peroxide mu Kusungunuka kwa Cellulose:
Hydrogen peroxide imapereka zabwino zingapo pakusungunuka kwa cellulose poyerekeza ndi njira zachikhalidwe:
Kugwirizana kwa Zachilengedwe: Mosiyana ndi mankhwala amphamvu monga sulfuric acid kapena chlorine solvents, hydrogen peroxide ndi yabwino kwambiri ndipo imawola kukhala madzi ndi mpweya pansi pa nyengo yofatsa. Khalidwe loteteza chilengedweli limapangitsa kuti ikhale yoyenera kukonza cellulose komanso kuchotsa zinyalala.
Zinthu Zochepa Zokhudza Kuyankha: Kusungunuka kwa cellulose komwe kumachitika chifukwa cha hydrogen peroxide kumatha kuchitika pansi pa kutentha pang'ono komanso kupanikizika pang'ono, kuchepetsa kugwiritsa ntchito mphamvu ndi ndalama zogwirira ntchito poyerekeza ndi mankhwala a acid hydrolysis kapena ionic liquid.
Kugawanika kwa okosijeni kosankhidwa: Kugawanika kwa okosijeni kwa ma glycosidic bonds ndi hydrogen peroxide kumatha kulamulidwa pamlingo wina, zomwe zimapangitsa kuti ma cellulose chain asinthidwe mosankhidwa komanso kupanga zinthu zina zomwe zimapangidwa ndi thupi zomwe zili ndi makhalidwe enaake.
Kugwiritsa Ntchito Mosiyanasiyana: Zinthu zosungunuka za cellulose zomwe zimapezeka kuchokera ku hydrogen peroxide-mediated dissolving zitha kugwiritsidwa ntchito m'magawo osiyanasiyana, kuphatikizapo kupanga biofuel, zipangizo zogwirira ntchito, zipangizo zamankhwala, ndi kuchiza madzi otayira.
Mavuto ndi Malangizo a M'tsogolo:
Ngakhale kuti ili ndi mphamvu zabwino, kusungunuka kwa cellulose komwe kumachitika chifukwa cha hydrogen peroxide kukukumana ndi mavuto ambiri komanso madera ena oti akonze:
Kusankha ndi Kubereka: Kupeza zokolola zambiri za soluble cellulose derivatives ndi zotsatira zochepa zoyipa kumakhalabe vuto, makamaka pa zakudya zovuta za biomass zomwe zili ndi lignin ndi hemicellulose.
Kukulitsa ndi Kuphatikiza Njira: Kukulitsa njira zosungunula maselo a cellulose zochokera ku hydrogen peroxide kufika pamlingo wa mafakitale kumafuna kuganizira mosamala kapangidwe ka reactor, kubwezeretsa zosungunulira, ndi njira zogwirira ntchito pansi kuti zitsimikizire kuti zachuma zikuyenda bwino komanso kuti chilengedwe chikhale cholimba.
Kupanga kwa Catalyst: Kupanga ma catalyst ogwira ntchito bwino kuti hydrogen peroxide iyambe kugwira ntchito komanso kuti cellulose oxidation ikhale yofunikira kwambiri popititsa patsogolo kuchuluka kwa zochita ndi kusankha bwino zinthu pamene akuchepetsa kuchuluka kwa catalyst ndi kupanga zinthu zina.
Kutsimikizira Zinthu Zina: Njira zotsimikizira zinthu zina zomwe zimapangidwa panthawi ya kusungunuka kwa cellulose pogwiritsa ntchito hydrogen peroxide, monga carboxylic acids kapena shuga wa oligomeric, zitha kupititsa patsogolo kukhazikika ndi kukhazikika kwachuma kwa njirayi.
Hydrogen peroxide ili ndi lonjezo lalikulu ngati chosungunulira chobiriwira komanso chosinthika pakusungunuka kwa cellulose, chomwe chimapereka zabwino monga kuyanjana ndi chilengedwe, momwe zinthu zimachitikira pang'ono, komanso kusungunuka kwa okosijeni kosankhidwa. Ngakhale kuti pali zovuta zomwe zikuchitika, kupitilizabe kufufuza komwe cholinga chake ndi kufotokoza njira zomwe zimayambira, kukonza magawo a reaction, komanso kufufuza momwe zinthu zimagwiritsidwira ntchito kudzawonjezera kuthekera ndi kukhazikika kwa njira zozikidwa pa hydrogen peroxide kuti cellulose iwonjezereke.
Nthawi yotumizira: Epulo-10-2024