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The Study On The Application Of The Bronsted Acidic Ionic Liquids In Cellulose Hydrolysis

Posted on:2013-09-02Degree:MasterType:Thesis
Country:ChinaCandidate:W W XiaoFull Text:PDF
GTID:2231330392452687Subject:Chemical processes
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As the fossil fuel is used in more and more aspects and the reserves are tend todecline quickly, an appeal for protecting the environment and developing a kind ofnew clean energy is made. Cellulose is a reproducible resource which existsextensively in nature and has many applications especially that glucose can beobtained from cellulose degradation and can be converted to alcohol from zymosis.Alcohol is considered as a kind of clean energy and a substituent of fossil fuel. Thisapplication potential attracts public’s huge attention.As the structure and the properties of ionic liquids, some ionic liquids candissolve cellulose efficiently. Furthermore, functionalized ionic liquids possesscatalytic capability. In this paper, ionic liquids are applied in the whole process ofcellulose hydrolysis according to their specific properties in this study.In this study, cellulose is dissolved in a new ionic liquid solvent [BMIM]Clwhich is synthesized by a one-step alkylation reaction in a batch reactor. Six kinds ofacidic ionic liquids are prepared as catalyst to hydrolyze cellulose. The study of thecellulose hydrolysis is carried out systematically under different conditions forinstance the mass ratio of cellulose and Bronsted acidic ionic liquids is changed from1:2to1:4or the reaction temperature is changed from80℃to100℃in thisinvestigation, some influent factors including reaction temperature, retention time,concentrations of Bronsted acidic catalyst in system are all taken into consideration.The conclusion shows that1-methyl-3-propanesulfonic acid imidazoliumchloride(IL2) and N,N,N-triethyl-N-propanesulfonic acid ammonium hydrogensulfate(IL5) show better catalytic activity relatively in mild conditions among thesesynthesized acidic ionic liquid. The TRS yields are96.64%and99.41%respectively.Besides, for most part of synthesized acidic liquids, when the mass ratio of celluloseand Bronsted acidic ionic liquids is1:2and the reaction temperature is improved from80℃to100℃, the hydrolysis rate increases to a large extent. The TRS yield canreach the highest value in a shorter time, and the highest yield value has a bigimprovement. Besides the temperature, the structure and the concentrations of these acidic ionic liquids also play a important role in the production of the TRS.Furthermore, the preparation of the supported Bronsted acidic ionic liquid is alsoinvestigated in this paper.1-vinyl-3-propanesulfonic acid imidazolium is connected tothe macroporous silica, and the product has been measured through FTIR. The resultshows that1-vinyl-3-propanesulfonic acid imidazolium is linked with supportedmaterials by chemical bond. The synthesized supported Bronsted acidic ionic liquid isused in cellulose hydrolysis and it exhibits some activity. This discovery will provideanother potential for Bronsted acidic ionic liquids’ application.
Keywords/Search Tags:cellulose hydrolysis, pretreatment, Bronsted acidic ionic liquids, yield of TRS
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