Preparation Of Reducing Sugar Using Rice Straw Pretreated By Ionic Liquid And The Recycle Of The Ionic Liquid

Nowadays, we face with the challenges of the shortage of resources and theissues of environment. Much attention has been paid to biological energy source(BER), owning to its advantages of its great potentiality of raw material and lowcost and so on. The main function of the BER is an alternative to fossil energy,protecting the environment and promoting rural economic development. Chineserice production is the first place in the world, with a wealth of reserve resources.From the perspective as the economic value, environmental protection, and newenergy, we adopt ionic liquid in the pretreatment of straw and utilize processedcellulose and cellulase to prepare the reducing sugar. Then the recycled ionicliquid is utilized in the processing of straw to study the performance of therecycled ionic liquid.In the experiment, we have prepared the [AMM]Cl, and its structure wasdetermined through FT-IR and1HNMR. Rice straw cellulose was dissolved in theionic liquids, then the mechanism of the process was investigated by studying theinfluence factors (the ratio of solid-liquid, temperature, and dissolving time).Then the most appropriate parameters of solution were obtained: the ratio ofsolid-liquid is1:9,110℃and2hours.The recovery of the waste ionic liquid [AMIM]Cl reached90%through themethod of the reduced pressure distillation. The structure of [AMIM]Cl was notchanged after recovery by FT-IR and1HNMR spectrum analysis. The [AMIM]Clwas used5time, the reducing sugar conversion rate reduces from82.08%to44.44%(the reducing sugar conversion rate of the untreated straw is31.94%),and the ionic liquid recovery rate decreases reduces from90%to25.32%.Through the SEM observation of the regenerated cellulose’s microstructure, we found, the damage for cellulose will be weakened with used times of ionicliquids increasing.The residues, what was separated after recycle of [AMIM]Cl, is the keyfactors in the decline of recycle rate. The mixture components are analyzed usingthese methods (SEM, FT-IR and XPS). The mixture contains straw by theanalysis of the morphology; It proved that there is [AMIM]Cl in the residues byFT-IR and C1s, O1s, N1s and Cl2p determined by XPS. The residues is mixtureof straw and [AMIM]Cl.