I-Cellulose, i-polymer enobuningi ye-organic emhlabeni, iyingxenye ebalulekile ye-biomass kanye nezinto ezahlukahlukene zezimboni. Ubuqotho bayo obumangalisayo bubeka izinselelo zokuqhekeka kwalo okusebenzayo, okubalulekile kwezicelo ezifana nokukhiqizwa kwe-biofuel kanye nokuphathwa kwemfucuza. IHydrogen Peroxide (H2O2) ivele njengommeleli we-cellulose dicideration ngenxa yemvelo yayo yemvelo kanye ne-oxidizing Properties.
Isingeniso:
I-Cellulose, i-polysaccharide ehlanganiswe ama-glucose amayunithi axhumene nezibopho ze-β-1,4-glycosidic, iyingxenye enkulu yesakhiwo ezindongeni zamaseli ezitshalo. Inala yayo e-biomass yenza kube yisisetshenziswa esihle sezimboni ezahlukahlukene, kufaka phakathi iphepha ne-pulp, izindwangu kanye ne-biioenergy. Kodwa-ke, inethiwekhi eqinile ye-Hydrogen Bonding ngaphakathi kwe-cellulose fibrils inikela ngokumelana nokuchithwa kwama-solvents amaningi, ibeka izinselelo zokusetshenziswa kwayo kahle kanye nokuphinda usebenzise kabusha.
Izindlela zendabuko zokuqothulwa kwendabuko kwe-cellulose kuhilela izimo ezinzima, ezifana nama-acid ahlanganisiwe noma ama-ionic ketshezi, avame ukuhlotshaniswa nokukhathazeka kwemvelo kanye nokusetshenziswa kwamandla okuphezulu. Ngokuphambene nalokho, i-hydrogen peroxide inikeza enye indlela ethembisayo ngenxa yemvelo yayo emnene oxidizing kanye nethuba lokucutshungulwa kwe-cellulose yemvelo. Leli phepha lihlela ezinhlwini ezingaphansi kwe-hydrogen petoxide - Ukuqothulwa kwe-cellulose-mellulose ukuchithwa futhi kuhlolwe ukusebenza kwayo kanye nezicelo ezisebenzayo.
Izindlela zokuchithwa kwe-cellulose nge-hydrogen peroxide:
Ukuchithwa kwe-cellulose nge-hydrogen peroxide kufaka phakathi ukusabela okuyinkimbinkimbi kwamakhemikhali, ikakhulukazi ama-cleavage ama-glycosidic bond kanye nokuphazamiseka kwe-intermolecular lyrogen bonding. Inqubo ngokujwayelekile iqhubeka ngezinyathelo ezilandelayo:
I-Oxidation of Hydroxyl Amaqembu: I-Hydrogen Peroxide iphendula ngamaqembu e-cellulose hydroxyl, okuholela ekwakhekeni kwama-hydroxyls ( Lezi zinqwaba zihlasela izibopho ze-glycosidic, ziqala ukukhishwa kwethempeli nokukhiqiza izingcezwana ezimfushane zeselula.
Ukuphazamiseka kwe-hydrogen Bonding: Ama-Hydroxyl Radecals abuye aphazamise futhi inethiwekhi yokubopha ama-hydrogen phakathi kwamaketanga we-cellulose, enza buthaka ukwakheka okuphelele kanye nokwenza lula ukwakheka kwe-ilwift kanye nokwenza lula.
Ukwakheka kokutholwa kokutholwa: ukucekelwa phansi kwe-oxidative of cellulose imiphumela ekwakhekeni kwama-Intermemediales ancibilikisiwe, afana nama-carboxylic acid, ama-aldehydes, nama-ketones. Lezi zinto zokuphumula zinomthelela kwinqubo yokuchitheka ngokwandisa i-soubity kanye nokunciphisa ukubonwa.
I-Depolymerization kanye ne-Fregenation: Ukuphendula okwengeziwe kanye nokuphendula kwe-cleavage kuholela ekunikezelweni kwamaketanga ama-cellulose ema-oligomers amafushane futhi ekugcineni ukuze kuncishiswe ushukela noma eminye imikhiqizo esezingeni eliphansi.
Izici ezithinta i-hydrogen peroxide-melsocide disculution disolution:
Ukusebenza kahle kwe-cellulose disolution usebenzisa i-hydrogen peroxide kuthonywa yizici ezahlukahlukene, kufaka phakathi:
Ukuhlushwa kwe-hydrogen peroxide: ukugxila okuphezulu kwe-hydrogen peroxide kuvame ukulandela amanani okusa asabela ngokushesha kanye nokuwohloka okukhulu kwesendlalelo. Kodwa-ke, ukugxila okuphezulu ngokweqile kungaholela ekuvuseleleni uhlangothi noma imikhiqizo engathandeki.
I-PH kanye nokushisa: I-PH yamathonya aphakathi aphakathi esizukulwaneni se-Hydroxyl radicals kanye nokuqina kokutholwa kokutholwa. Izimo ezilinganiselayo ze-acidic (i-PH 3-5) zivame ukuthandwa ukuthuthukisa i-cellubity yeselula ngaphandle kokuwohloka okukhulu. Ngokwengeziwe, izinga lokushisa lithinta ukuphendula kwe-kinetics, okunamazinga okushisa aphezulu ngokuvamile okusheshisa inqubo yokuchitheka.
Ukuba khona kwama-Catalysts: I-Transition yensimbi yensimbi, efana ne-iron noma ithusi, ingahle ikhuthaze ukubola kwe-hydrogen peroxide futhi ithuthukise ukwakheka kwama-hydroxyl ama-radicals. Kodwa-ke, ukukhethwa kwe-catalyst kanye nokuhlushwa kwawo kumele kwenziwe kahle ukunciphisa ukusabela okuhlangene futhi kuqinisekiswe ikhwalithi yomkhiqizo.
I-cellulose morphology kanye ne-crystallity: Ukutholakala kwamaketanga we-cellulose ku-hydrogen peroxide kanye nama-hydroxyl radicals kuthonywa yi-morphology ye-morphology ne-crystalline. Izifunda ze-Amorphous zitholakala kakhulu ekuwohlokeni kunezizinda ze-crystalline, ezidingekayo amasu okuhlekisa noma ukuguqulwa ukuze athuthukise ukufinyeleleka.
Izinzuzo kanye nokusetshenziswa kwe-hydrogen peroxide eCellulose Disolution:
I-Hydrogen Peroxide inikeza izinzuzo eziningana zokuchithwa kweselula ngokuqhathaniswa nezindlela ezijwayelekile:
Ukuvumelana Kwemvelo: Ngokungafani namakhemikhali anokhahlo okufana ne-sulfuric acid noma ama-solvents ahlanganisiwe, i-hydrogen peroxide yi-bevin futhi ibola ngamanzi kanye nomoya-mpilo ngaphansi kwezimo ezimnene. Le mvelo enobungani bemvelo yenza ilungele ukucubungula okuqhubekayo kwe-cellulose kanye nokuxoshwa kwemfucuza.
Izimo Zokusabela Ezimnene: Ukuchithwa kwe-perrogen peroxide-melsoside-melsulose ukuchithwa kungenziwa ngaphansi kwezimo ezimnene zokushisa kanye nengcindezi, kunciphisa ukusetshenziswa kwamandla kanye nezindleko zamandla okuqhathaniswa ne-acid hydrolysis ephezulu noma yokwelashwa kwe-ionic liquid.
Ukukhetha i-oxidation: I-Oxidative Cleavage yama-glycosidic bond nge-hydrogen peroxide ingalawulwa ngezinga elithile, ukuvumela ukuguqulwa kwamaketanga okukhethiwe kanye nokukhiqizwa kwezinto ezitholwayo ezihambisanayo ezinezakhiwo ezithile.
Izicelo eziguquguqukayo: Ukuncishiswa kwama-cellule clulele
Izinselelo nezinkomba zesikhathi esizayo:
Naphezu kwezimfanelo zayo ezithembisayo, i-hydrogen petoxide-melsonide - Ukuchithwa kwe-cellulose ukuchithwa kobhekana nezinselelo eziningi nezindawo zokwenza ngcono:
Ukukhetha kanye nesivuno: Ukuthola isivuno esiphakeme sokutholwa okuningana kwe-cellulose decivatives ngokuphendula okungakanani okuncane kuhlala kuyinselelo, ikakhulukazi ukuthola inselelo, ikakhulukazi kuma-feignocks ayinkimbinkimbi e-bignin ne-hemicellulose.
Ukuhlanganiswa kokulinganisa kanye nokuhlanganiswa kwenqubo: Ukulinganisa izinqubo zokuncishiswa kwe-perrogen perrogude kumazinga wezimboni kudinga ukucubungula ngokucophelela ukwakheka kwe-reactor, ukululama kwe-solvent, kanye nezinyathelo ezansi nomkhosi wokuqinisekisa ukusebenza kwezomnotho kanye nokusimama kwemvelo.
Ukuthuthukiswa kweCatalyst: Idizayini yama-catalysts asebenzayo e-hydrogen peroxide activation kanye ne-cellulose oxidation ibalulekile ekwandiseni amanani okusabela nokukhetha ngenkathi unciphisa ukulayisha kwe-catalyst kanye nokwakheka komkhiqizo.
I-Valorization yemikhiqizo eyenziwe yimikhiqizo: amasu okuvikela imikhiqizo eyenziwe ngemikhiqizo eyenziwe ngesikhathi sokuchithwa kwe-hydrogen peroxide-melsosiated, njengama-carboxylic acid noma ama-oligomeric, angaphinde athuthukise ukuqina kokuqina kanye nokusebenza kwezomnotho kwenqubo.
I-Hydrogen Peroxide ibamba isithembiso esibalulekile njenge-solvent eluhlaza futhi eguquguqukayo ye-cellulose disolution, enikeza izinzuzo njengokuhambisana kwezemvelo, imibandela yokusabela emnene, kanye nokukhetha i-oxidation. Naphezu kwezingqinamba eziqhubekayo, kwaqhubeka nemizamo yocwaningo ehlose ukucacisa izindlela eziyisisekelo, ukulungiselela amapharamitha okuphendula, nokuhlola izinhlelo zokusebenza zenoveli kuzothuthukisa ukwenzeka nokusimama kwezinqubo ezenzelwe i-hydrogen ze-cellulose valorization.
Isikhathi sePosi: Apr-10-2024