Ma cellulose, polima wochuluka kwambiri padziko lapansi, amapanga gawo lalikulu la biomass ndi zida zosiyanasiyana zamafakitale. Kapangidwe kake kodabwitsa kamakhala ndi zovuta pakuwonongeka kwake, ndikofunikira kwambiri pakugwiritsa ntchito monga kupanga mafuta amafuta ndi kuwongolera zinyalala. Hydrogen peroxide (H2O2) yatulukira ngati yomwe ingathe kusungunuka pa cellulose chifukwa cha chikhalidwe chake chosakhala bwino komanso okosijeni.
Chiyambi:
Cellulose, polysaccharide yopangidwa ndi mayunitsi a shuga olumikizidwa ndi β-1,4-glycosidic bond, ndi gawo lalikulu pamakoma a cell cell. Kuchuluka kwake mu biomass kumapangitsa kukhala chida chowoneka bwino m'mafakitale osiyanasiyana, kuphatikiza mapepala ndi zamkati, nsalu, ndi bioenergy. Komabe, maukonde amphamvu a haidrojeni omangirira ma cellulose fibrils amawapangitsa kuti asasungunuke muzosungunulira zambiri, zomwe zimadzetsa zovuta pakugwiritsa ntchito bwino ndikubwezeretsanso.
Njira zachikale zakusungunuka kwa cellulose zimaphatikizapo mikhalidwe yovuta, monga ma asidi okhazikika kapena zakumwa za ayoni, zomwe nthawi zambiri zimagwirizana ndi kukhudzidwa kwa chilengedwe komanso kugwiritsa ntchito mphamvu kwambiri. Mosiyana ndi zimenezi, hydrogen peroxide imapereka njira ina yodalirika chifukwa cha chikhalidwe chake chochepa cha okosijeni komanso kuthekera kokonza mapadi a cellulose. Pepalali likuwunika momwe hydrogen peroxide-mediated cellulose isungunuka ndikuwunika momwe imagwirira ntchito komanso momwe imagwiritsidwira ntchito.
Njira za Kusungunuka kwa Cellulose ndi Hydrogen Peroxide:
Kusungunuka kwa cellulose ndi hydrogen peroxide kumakhudzanso zovuta zamagulu, makamaka oxidative cleavage ya glycosidic bond ndi kusokonezeka kwa intermolecular hydrogen bonding. Ndondomekoyi imachitika motsatira njira izi:
Oxidation of Hydroxyl Groups: Hydrogen peroxide imakhudzidwa ndi magulu a cellulose hydroxyl, zomwe zimapangitsa kupanga ma hydroxyl radicals (•OH) kudzera mu Fenton kapena Fenton-ngati reactions pamaso pa transition metal ions. Ma radicals awa amalimbana ndi zomangira za glycosidic, kuyambitsa kukwera kwa unyolo ndikupanga tizidutswa tating'ono ta cellulose.
Kusokonezeka kwa Kumangirira kwa Hydrogen: Ma radicals a Hydroxyl amasokonezanso maukonde a haidrojeni pakati pa maunyolo a cellulose, kufooketsa kapangidwe kake ndikupangitsa kuti kuthetsedwe.
Kupanga Zinthu Zosungunuka Zosungunuka: Kuwonongeka kwa okosijeni kwa cellulose kumapangitsa kupanga zinthu zosungunuka m'madzi, monga ma carboxylic acid, aldehydes, ndi ketones. Zotengera izi zimathandizira pakuwonongeka pakuwonjezera kusungunuka komanso kuchepetsa kukhuthala.
Depolymerization ndi Fragmentation: Kuchuluka kwa okosijeni ndi kung'ambika kumapangitsa kuti unyolo wa cellulose usungunuke kukhala ma oligomer aafupi ndipo pamapeto pake amasungunuka shuga kapena zinthu zina zotsika kwambiri zama cell.
Zomwe Zimakhudza Kusungunuka kwa Ma cellulose Hydrogen Peroxide-Mediated Cellulose:
Kuchita bwino kwa kusungunuka kwa cellulose pogwiritsa ntchito hydrogen peroxide kumatengera zinthu zosiyanasiyana, kuphatikiza:
Kuchuluka kwa Hydrogen Peroxide: Kuchuluka kwa hydrogen peroxide nthawi zambiri kumapangitsa kuti anthu azichita zinthu mwachangu komanso kuwonongeka kwa cellulose. Komabe, kuchulukirachulukira kungayambitse kuyabwa kapena zinthu zina zosafunikira.
pH ndi Kutentha: The pH ya reaction sing'anga imakhudza m'badwo wa ma hydroxyl radicals komanso kukhazikika kwa zotumphukira za cellulose. Mkhalidwe wa acidic (pH 3-5) nthawi zambiri umakonda kupititsa patsogolo kusungunuka kwa cellulose popanda kuwonongeka kwakukulu. Kuonjezera apo, kutentha kumakhudza ma kinetics, ndi kutentha kwapamwamba nthawi zambiri kumathandizira kusungunuka.
Kukhalapo kwa Zothandizira: Ma ayoni achitsulo, monga chitsulo kapena mkuwa, amatha kuwononga hydrogen peroxide ndikupangitsa kuti ma hydroxyl radicals apangidwe. Komabe, kusankha chothandizira ndi ndende yake kuyenera kukonzedwa mosamala kuti muchepetse zomwe zimachitika ndikuwonetsetsa kuti zinthu zili bwino.
Cellulose Morphology and Crystallinity: Kufikika kwa maunyolo a cellulose ku hydrogen peroxide ndi ma hydroxyl radicals kumatengera mawonekedwe a zinthu ndi mawonekedwe a crystalline. Madera aamorphous ndi omwe amatha kuwonongeka kwambiri kuposa madera okhala ndi makristalo ambiri, zomwe zimafunikira kusamalidwa kapena kusintha njira kuti zitheke kupezeka.
Ubwino ndi Kugwiritsa Ntchito Hydrogen Peroxide mu Kuwonongeka kwa Ma cellulose:
Hydrogen peroxide imapereka maubwino angapo pakusungunuka kwa cellulose poyerekeza ndi njira wamba:
Kugwirizana kwa Chilengedwe: Mosiyana ndi mankhwala owopsa monga sulfuric acid kapena zosungunulira za chlorinated, hydrogen peroxide ndi yabwino kwambiri ndipo imawola kukhala madzi ndi mpweya m'malo ochepa. Khalidwe losakonda zachilengedweli limapangitsa kuti likhale loyenera kukonzanso mapadi a cellulose komanso kukonza zinyalala.
Zinthu Zochepa Zochita: Kusungunuka kwa hydrogen peroxide-mediated cellulose kumatha kuchitika pansi pa kutentha ndi kupanikizika, kuchepetsa kugwiritsira ntchito mphamvu ndi ndalama zogwirira ntchito poyerekeza ndi kutentha kwa asidi hydrolysis kapena mankhwala a ayoni amadzimadzi.
Selective Oxidation: The oxidative cleavage ya glycosidic bond ndi hydrogen peroxide imatha kuwongoleredwa pamlingo wina, kulola kusinthidwa kosankhidwa kwa unyolo wa cellulose ndikupanga zotumphukira zogwirizana ndi zinthu zinazake.
Ntchito Zosiyanasiyana: Zopangidwa ndi cellulose zosungunuka zomwe zimasungunuka kuchokera ku hydrogen peroxide-mediated dissolution zitha kugwiritsidwa ntchito m'magawo osiyanasiyana, kuphatikiza kupanga mafuta a biofuel, zida zogwirira ntchito, zida zamankhwala, ndikuthira madzi oyipa.
Mavuto ndi mayendedwe amtsogolo:
Ngakhale zili zolimbikitsa, kusungunuka kwa cellulose ya hydrogen peroxide-mediated cellulose kumakumana ndi zovuta zingapo komanso madera omwe akufunika kusintha:
Kusankha ndi Zokolola: Kupeza zokolola zambiri za zotumphukira zosungunuka za cellulose zomwe sizimakhudzidwa pang'ono kumakhalabe vuto, makamaka pazakudya za biomass zomwe zimakhala ndi lignin ndi hemicellulose.
Kukulitsa ndi Kuphatikiza Njira: Kukulitsa njira zosungunula ma cellulose a hydrogen peroxide kumagulu amakampani kumafuna kulingalira mozama za kapangidwe ka riyakitala, kubwezeretsa zosungunulira, ndi masitepe oyendetsa pansi kuti zitsimikizire kuti chuma chikuyenda bwino komanso kukhazikika kwa chilengedwe.
Kukula kwa Catalyst: Kapangidwe kazinthu zopangira hydrogen peroxide activation ndi cellulose oxidation ndizofunikira kuti ziwonjezeke momwe zimachitikira komanso kusankha kwina kwinaku mukuchepetsa kutsitsa koyambitsa ndi kupanga mwazinthu.
Kuchulukitsa kwa Zamgulu: Njira zowonetsetsa kuti zinthu zomwe zimapangidwa panthawi ya hydrogen peroxide-mediated cellulose dissoluation, monga ma carboxylic acid kapena shuga wa oligomeric, zitha kupititsa patsogolo kukhazikika kwachuma komanso kukhazikika kwachuma.
Hydrogen peroxide imakhala ndi lonjezo lalikulu ngati chosungunulira chobiriwira komanso chosunthika pakusungunuka kwa cellulose, kumapereka zabwino monga kuyanjana ndi chilengedwe, kusachitapo kanthu pang'ono, komanso makutidwe ndi okosijeni osankhidwa. Ngakhale pali zovuta zomwe zikupitilira, kafukufuku wopitilirabe womwe umafuna kuwunikira njira zomwe zakhazikitsidwa, kuwongolera momwe angachitire, ndikuwunikanso ntchito zaposachedwa kupititsa patsogolo kuthekera komanso kukhazikika kwa njira za hydrogen peroxide za cellulose valorization.
Nthawi yotumiza: Apr-10-2024