Cellulose, muaj ntau ntau tshaj organic polymer hauv ntiaj teb, suav nrog ib qho tseem ceeb ntawm biomass thiab ntau cov ntaub ntawv muaj ntau yam. Nws cov kev ntseeg ncaj ncees zoo tshaj plaws rau nws txoj kev muaj txiaj ntsig zoo, tseem ceeb rau kev siv roj biofuel ntau lawm thiab khib nyiab. Hydrogen peroxide (H2O2) tau tawm los ua tus neeg sib tw ua rau cellulose tawg vim nws ib puag ncig benign xwm thiab oxidizing tej yam.
Taw qhia:
Cellulose, ib pawg polysaccharide muaj cov roj haleacepred los ntawm β-1,4-glycosidic bonds, yog ib qho kev sib tw loj hauv cov phab ntsa cell. Nws cov nplua nuj nyob hauv biomass ua rau nws muaj peev xwm txaus nyiam rau ntau yam kev lag luam, suav nrog ntawv thiab pulp, textiles, thiab bioenergy. Txawm li cas los xij, tus muaj zog hydrogen sib txuas network nyob rau hauv cov cellulose ribrils nws tiv taus kev sib tw hauv cov kuab tshuaj feem ntau, cov nyom ntawm kev siv thiab rov siv dua tshiab.
Cov txheej txheem ib txwm muaj rau cellulose yaj ua cov xwm txheej hnyav, kua ntau zaus, uas feem ntau cuam tshuam nrog kev txhawj xeeb ib puag ncig thiab kev siv hluav taws xob. Nyob rau hauv sib piv, hydrogen peroxide muaj kev xaiv kev cog lus vim nws cov tshuaj oxidizing thiab muaj peev xwm rau ib puag ncig cellulose kev ua. Daim ntawv no delves rau hauv cov txheej txheem rau hauv hydrogen peroxide-kho hlwb medulose thiab ntsuas nws txoj kev ua tau zoo thiab siv tau.
Kev siv hluav taws xob ntawm cellulose xaus los ntawm hydrogen peroxide:
Kev sib cais ntawm cov cellulose los ntawm hydrogen peroxide cuam tshuam nrog cov tshuaj lom neeg uas nyuaj heev, feem ntau ntawm glycosidic bonds thiab cuam tshuam ntawm cov kev sib koom tes hydrogen khi. Cov txheej txheem feem ntau tau ua los ntawm cov kauj ruam hauv qab no:
Oxidation ntawm pawg neeg hydroxyl: Hydrogen peroxide reacts nrog cov pab pawg hydroxyl radicals (• Henon-zoo li cov kev coj ua nyob rau hauv lub xub ntiag ntawm kev hloov tsheb hlau ions. Cov radicals tawm tsam glycosidic khi, pib cov kev soj ntsuam chanission thiab ua kom muaj kev sib tsoo cellulose luv luv.
Kev cuam tshuam ntawm hydrogen kev: Hydroxyl Radicals kuj cuam tshuam txog hydrogen tsev sib txuas ntawm cov qauv cellulose, tsis muaj cov txheej txheem sib txawv thiab ua kom muaj kev nyuaj siab.
Tsim ntawm soluble derivatives: cov oxidative kev ua rau muaj kev tsim cov dej-soluble intermediates, xws li carboxylic acids, aldehydes, thiab ketones. Cov txheej txheem no pab txhawb rau cov txheej txheem sib cais los ntawm kev nce solubility thiab txo viscosity.
Depolymerization thiab Fragmentation: Ntxiv oxidation thiab qhov kev sib tw ntawm kev sib tw ntawm lub cev nqaij qab zib thiab thaum kawg rau cov khoom lag luam tsawg-molecular-hnyav.
Yam cuam tshuam rau hydrogen peroxide-deliated cellulose cellulose yaj:
Kev ua tau zoo ntawm cellulose yaj saub siv hydrogen peroxide yog cuam tshuam los ntawm ntau yam, suav nrog:
Concentration ntawm hydrogen peroxide: ntau ntau ntau ntawm hydrogen peroxide feem ntau ua rau muaj kev cuam tshuam ntau dua thiab muaj ntau yam kev cuam tshuam cellulose ntau yam. Txawm li cas los xij, kev muaj ntau dhau yuav ua rau cov khoom seem lossis cov khoom tsis xav tau.
PH thiab kub: lub ph ntawm cov tshuaj tiv thaiv nruab nrab ntawm cov khoom ntawm hydroxyl radicals thiab qhov ruaj khov ntawm cellulose derivatives. Kev mob siab rau acidic (pH 3-5) feem ntau nyiam txhim kho cellulose solubility tsis muaj kev cuam tshuam tseem ceeb. Ib qho ntxiv, qhov kub nyhiab cuam tshuam kinetics, nrog qhov kub siab dua feem ntau ua nrawm dua cov txheej txheem sib cais.
Muaj cov catalysts: hloov cov hlau ions, xws li tooj hlau lossis tooj liab, tuaj yeem ua kom cov decomposition hydrogen peroxide thiab txhim kho kev tsim ntawm hydroxyl radicals. Txawm li cas los xij, cov kev xaiv ntawm catalyst thiab nws txoj kev xav yuav tsum ua kom zoo zoo kom txo cov khoom seem thiab ua kom cov khoom lag luam zoo.
Cellulose morpose thiab crystalloology: qhov tau txais kev nkag mus rau hydrogen peroxide thiab hydroxyl radicals yog cuam tshuam los ntawm cov khoom siv morphology thiab crystalline qauv. Amorphous thaj chaw muaj kev cuam tshuam ntau dua li kev cuam tshuam ntau dua li cov qauv siv crystalline zoo, tsim nyog ua ntej lub tswv yim los txhim kho kev siv tau.
Cov txiaj ntsig zoo thiab cov ntawv thov ntawm hydrogen peroxide hauv cellulose yaj:
Hydrogen Peroxide muaj ntau qhov zoo rau cellulose yaj piv rau cov hau kev uas pom zoo:
Kev sib xyaw ua ke ib puag ncig: tsis muaj tshuaj lom neeg xws li cov tshuaj sulfuric, hydrogen peroxide yog cov denign thiab decomposes rau hauv dej thiab oxygen nyob rau hauv cov mob me. Qhov kev ua phooj ywg ib puag ncig no ua rau nws haum rau kev ua kom ncaj ncees cellulose thiab pov tseg pov tseg.
Cov tshuaj tiv thaiv me me: hydrogen peroxide me me-kho tshuaj cellulose cellulose cellulute cellulution thiab lub siab ua haujlwm ntau piv rau cov kua qaub kub lossis kev kho kom zoo.
Xaiv oxidation: cov oxidative cleagage ntawm hydrogen peroxide tuaj yeem tswj hwm cov saw hlau thiab kev tsim cov khoom sib txuas nrog cov khoom tshwj xeeb.
Cov ntawv thov ntau ntau: cov soluble cellulose derivatives tau los ntawm hydrogen peroxide muaj cov ntawv thov muaj peev xwm nyob hauv ntau cov ntawv thov hauv cov ntawv siv rau kev siv tau hauv ntau yam khoom siv muaj peev xwm ua tau nyob rau hauv ntau yam cuab yeej muaj peev xwm ua tau nyob rau hauv ntau cov ntawv thov, xws li kev kho cov cuab yeej siv, thiab kev kho kom zoo.
Cov Kev Sib Tw thiab Yav Tom Ntej:
Txawm hais tias nws cov lus cog tseg uas muaj kev cog lus rau, hydrogen peroxide-doliated cellulose cellulose cellulose cellulution ntsib ntau cov kev sib tw thiab thaj chaw rau kev txhim kho:
Xaiv thiab tawm los: ua tiav high loo ntawm soluble cellulose tseem muaj kev sib tw, tshwj xeeb rau cov biomass feedtocks muaj lignemulose.
Cov txheej txheem teev thiab cov txheej txheem sib xyaw ua ke: ntsuas cov txheej txheem kev ua kom zoo nkauj ntawm cov neeg muaj kev sib koom tes ua kom muaj kev lag luam kom ntseeg tau thiab ib puag ncig kev lag luam thiab ib puag ncig.
Kev txhim kho kev txhim kho catalyst: kev tsim ntawm cov tshuaj tua kab mob hydrogen ua kom zoo nkauj thiab xaiv cov tshuaj tiv thaiv thiab kev tsim cov khoom lag luam.
Muaj kev vam meej ntawm cov khoom lag luam: cov tswv yim rau kev tsim txiaj ntsig los ntawm hydrogylic muaj suab thaj thiab kev siv hluav taws xob ntau dua thiab kev siv nyiaj txiag.
Hydrogen Peroxide Hurs tseem ceeb cog lus tias yog cov lus cog tseg ntsuab thiab muaj ntau yam xws li ib puag ncig, thiab kev xaiv oxidation, thiab xaiv oxidation. Txawm hais tias kev sib tw sib tw, txuas ntxiv kev tshawb fawb tau npaj tseg, txhim kho cov txheej txheem ntawm hydrogen peroxide txuas ntxiv rau cellulose valorization.
Lub Sijhawm Post: Apr-10-2024