I-Cellulose, i-polymer yezinto eziphilayo egcwele kakhulu eMhlabeni, yenza ingxenye enkulu ye-biomass nezinto ezihlukahlukene zezimboni.Ubuqotho bayo obumangalisayo besakhiwo budala izinselele ekubhidlikeni kwayo ngokuphumelelayo, okubalulekile ekusetshenzisweni okufana nokukhiqizwa kwe-biofuel nokulawulwa kwemfucuza.I-Hydrogen peroxide (H2O2) iqhamuke njengento engase ibe yikhandidethi yokuhlakazwa kwe-cellulose ngenxa yemvelo yayo enobungozi bemvelo kanye nezakhiwo ze-oxidizing.
Isingeniso:
I-Cellulose, i-polysaccharide eyakhiwe amayunithi e-glucose axhunywe ngamabhondi e-β-1,4-glycosidic, iyisakhi esiyinhloko sesakhiwo ezindongeni zamaseli ezitshalo.Ukuchichima kwayo ku-biomass kuyenza ibe yinsiza ekhangayo ezimbonini ezahlukahlukene, kufaka phakathi iphepha ne-pulp, izindwangu, kanye ne-bioenergy.Kodwa-ke, inethiwekhi eqinile yokubopha i-hydrogen ngaphakathi kwe-cellulose fibrils iyenza imelane nokuncibilika kuzincibilikisi eziningi, okuletha izinselele ekusetshenzisweni kwayo ngempumelelo nokugaywa kabusha.
Izindlela ezivamile zokuchithwa kwe-cellulose zifaka izimo ezinzima, ezifana nama-asidi agxilile noma uketshezi lwe-ionic, okuvame ukuhlotshaniswa nokukhathazeka kwemvelo kanye nokusetshenziswa okuphezulu kwamandla.Ngokuphambene, i-hydrogen peroxide inikeza enye indlela ethembisayo ngenxa yemvelo yayo ene-oxidizing ethambile kanye namandla okucubungula i-cellulose evumelana nemvelo.Leli phepha licubungula izindlela ezingaphansi kokuchithwa kwe-cellulose nge-hydrogen peroxide futhi lihlola ukusebenza kwayo nokusebenza okungokoqobo.
Izindlela zokuchithwa kweCellulose ngeHydrogen Peroxide:
Ukuqedwa kwe-cellulose nge-hydrogen peroxide kuhilela ukusabela kwamakhemikhali okuyinkimbinkimbi, ngokuyinhloko ukuhlukaniswa kwe-oxidative kwamabhondi e-glycosidic kanye nokuphazanyiswa kwe-intermolecular hydrogen bonding.Inqubo ngokuvamile iqhubeka ngezinyathelo ezilandelayo:
I-Oxidation Yamaqembu E-Hydroxyl: I-hydrogen peroxide ihlangana namaqembu e-cellulose hydroxyl, okuholela ekwakhekeni kwama-hydroxyl radicals (•OH) ngokusabela okufana ne-Fenton noma kwe-Fenton phambi kwama-ion ensimbi eshintshayo.Lawa ma-radicals ahlasela amabhondi e-glycosidic, aqala ukugoba kweketango futhi akhiqize izingcezu ze-cellulose ezimfushane.
Ukuphazanyiswa Kwe-Hydrogen Bonding: Ama-Hydroxyl radicals aphinde aphazamise inethiwekhi ye-hydrogen bonding phakathi kwamaketanga e-cellulose, enze buthaka isakhiwo sisonke futhi enze lula ukuxazululwa.
Ukwakhiwa Kwezinto Ezincibilikayo Ezincibilikayo: Ukuwohloka kwe-oxidative ye-cellulose kubangela ukwakheka kweziphakathi ezincibilika emanzini, njengama-carboxylic acid, ama-aldehydes, nama-ketone.Lokhu okuphuma kokunye kunomthelela enqubweni yokuhlakazeka ngokwandisa ukuncibilika nokunciphisa i-viscosity.
I-Depolymerization and Fragmentation: Ukuqhubekela phambili kwe-oxidation kanye nokuqhekeka kwe-cleavage kuholela ekwenziweni kwe-depolymerization yamaketanga e-cellulose abe ama-oligomer amafushane futhi ekugcineni kube ushukela oncibilikayo noma eminye imikhiqizo enesisindo esiphansi.
Izinto Ezithinta Ukuncibilika Kwe-Hydrogen Peroxide-Mediated Cellulose:
Ukusebenza kahle kokuchithwa kwe-cellulose kusetshenziswa i-hydrogen peroxide kuthonywa izici ezihlukahlukene, ezihlanganisa:
Ukugxila Kwe-Hydrogen Peroxide: Ukugxila okuphezulu kwe-hydrogen peroxide ngokuvamile kubangela amazinga okusabela ngokushesha kanye nokuwohloka okukhulu kwe-cellulose.Kodwa-ke, ukugxila okuphezulu ngokweqile kungaholela ekuphenduleni ohlangothini noma emikhiqizweni engathandeki.
I-pH kanye Nezinga Lokushisa: I-pH yendawo yokusabela ithonya ukukhiqizwa kwama-hydroxyl radicals kanye nokuzinza kokuphuma kokuphuma ku-cellulose.Izimo ezine-acidic emaphakathi (pH 3-5) zivame ukuncanyelwa ukuthuthukisa ukunyibilika kwe-cellulose ngaphandle kokuwohloka okukhulu.Ukwengeza, izinga lokushisa lithinta i-reaction kinetics, amazinga okushisa aphezulu ngokuvamile asheshisa inqubo yokuhlakazeka.
Ukuba khona Kwama-Catalysts: Ama-ion ensimbi eshintshayo, njengensimbi noma ithusi, angabangela ukubola kwe-hydrogen peroxide futhi athuthukise ukwakheka kwama-hydroxyl radicals.Kodwa-ke, ukukhetha kwe-catalyst kanye nokugxila kwayo kufanele kulungiselelwe ngokucophelela ukuze kuncishiswe ukusabela okuseceleni futhi kuqinisekiswe ikhwalithi yomkhiqizo.
I-Cellulose Morphology and Crystallinity: Ukufinyeleleka kwamaketango e-cellulose ku-hydrogen peroxide nama-hydroxyl radicals kuthonywa ukwakheka kwezinto kanye nesakhiwo sekristalu.Izifunda ezine-amorphous zisengozini yokuwohloka kunezizinda ezicwebe kakhulu, okwenza kudingeke amasu okwelapha kusengaphambili noma okushintsha ukuze kuthuthukiswe ukufinyeleleka.
Izinzuzo kanye nokusetshenziswa kwe-Hydrogen Peroxide ku-Cellulose Dissolution:
I-hydrogen peroxide inikeza izinzuzo ezimbalwa zokuchithwa kwe-cellulose uma kuqhathaniswa nezindlela ezivamile:
Ukuvumelana Kwemvelo: Ngokungafani namakhemikhali anonya njenge-sulfuric acid noma izinyibilikisi ezine-chlorine, i-hydrogen peroxide ayinabungozi futhi ibola ibe amanzi nomoya-mpilo ngaphansi kwezimo ezithambile.Lesi sici esivumelana nemvelo siyenza ifanelekele ukucutshungulwa kwe-cellulose okusimeme kanye nokulungisa imfucuza.
Izimo Zokusabela Ezincane: Ukuncibilika kwe-cellulose ye-hydrogen peroxide-mediated cellulose kungenziwa ngaphansi kwezimo ezithambile zokushisa nengcindezi, ukunciphisa ukusetshenziswa kwamandla nezindleko zokusebenza uma kuqhathaniswa ne-high-temperature acid hydrolysis noma ukwelapha uketshezi lwe-ionic.
I-Selective Oxidation: I-oxidative cleavage yamabhondi e-glycosidic nge-hydrogen peroxide ingalawulwa ngokwezinga elithile, okuvumela ukuguqulwa okukhethiwe kwamaketango e-cellulose kanye nokukhiqizwa kokuphuma kokunye okuhambisanayo okunezici ezithile.
Izicelo Ezihlukahlukene: Okuphuma kokunye okuncibilikayo kwe-cellulose okutholwe ekuhlakazweni kwe-hydrogen peroxide-mediated kungasetshenziswa emikhakheni eyahlukene, okuhlanganisa ukukhiqizwa kwe-biofuel, izinto ezisebenzayo, izisetshenziswa ze-biomedical, nokuhlanza amanzi angcolile.
Izinselelo Nezikhombisi-ndlela Ezizayo:
Naphezu kwezimfanelo zakho ezithembisayo, ukuchithwa kwe-cellulose nge-hydrogen peroxide-mediated kubhekene nezinselele ezimbalwa kanye nezindawo okufanele zenziwe ngcono:
Ukukhetha kanye Nokukhiqiza: Ukuthola isivuno esikhulu sokuphuma kokuphuma kwe-cellulose encibilikayo nokusabela okuseceleni okuncane kuhlala kuyinselele, ikakhulukazi ku-biomass feedstocks eyinkimbinkimbi equkethe i-lignin ne-hemicellulose.
I-Scale-Up and Process Integration: Ukukhuphula izinqubo zokuchithwa kwe-cellulose esekelwe ku-hydrogen peroxide emazingeni ezimboni kudinga ukucatshangelwa ngokucophelela kwesakhiwo se-reactor, ukubuyiswa kwe-solvent, nezinyathelo zokucubungula ezansi nomfula ukuze kuqinisekiswe ukusebenza komnotho kanye nokusimama kwemvelo.
Ukuthuthukiswa Kwe-Catalyst: Idizayini yama-catalysts asebenzayo okusebenza kwe-hydrogen peroxide kanye ne-cellulose oxidation ibalulekile ekuthuthukiseni amazinga okusabela nokukhetha kuyilapho kunciphisa ukulayishwa kwe-catalyst kanye nokwakheka komkhiqizo.
I-Valorization Yemikhiqizo Ekhiqizwa Ngayo: Amasu okuqinisekisa ukuthi umkhiqizo ukhiqizwa ngesikhathi sokuncibilikiswa kwe-cellulose ye-hydrogen peroxide-mediated, njengama-carboxylic acid noma ushukela we-oligomeric, angase athuthukise ukusimama kwawo wonke kanye nokusebenza kwezomnotho kwenqubo.
I-hydrogen peroxide inesithembiso esibalulekile njengesinyibilikisi esiluhlaza nesiguquguqukayo sokuchithwa kwe-cellulose, enikeza izinzuzo ezifana nokuhambisana kwemvelo, izimo zokusabela okuthambile, kanye ne-oxidation ekhethiwe.Naphezu kwezinselele eziqhubekayo, imizamo yocwaningo eqhubekayo ehloselwe ukucacisa izindlela eziyisisekelo, ukuthuthukisa imingcele yokusabela, nokuhlola izinhlelo zokusebenza zamanoveli kuzothuthukisa ukuba nokwenzeka nokusimama kwezinqubo ezisekelwe ku-hydrogen peroxide zokwenziwa kwe-cellulose valorization.
Isikhathi sokuthumela: Apr-10-2024