Ionic Liquid Pretreatment To Facilitate The Enzymic Hydrolysis Of Corn Stover

Corn stover is a renewable, cheap and widely available resource. It is mainly used in the production of energy by combustion in remote country. Approximately 20% of the corn stover is hemicellulose, mainly xylan. It is one of the most promising renewable feedstock for biological conversion to fuels and chemicals after hydrolyzed to fermentable sugars.Three kinds of ionic liquids(ILs) were synthesis through one-step quaternization reactions.The alkylation process possesses the advantages that a wide range of cheap haloalkanes are available, and the substitution reactions generally occur smoothly at reasonable temperatures. Furthermore, the halide salts formed can easily be converted into salts to other anions. 1-allyl-3-methylimidazolium chloride([AMIM]Cl),1-methy- -l([AMIM]CI),1-methyl-3-benzylimidazoliumchloride([BZMIM]Cl),l-ethyl-3-methyl-imidazoliu diethty phosphate ([C2MIM][(Et0)2PO2]) were characterized by means of 1HNMR. Dissolution and regeneration of cellulose in [AMIM]CI was investigated by of PLM observation and FTIR which found a rapid the dissolved cellulose into its crystalline and no derivation occured.Hydrolysis of cellulose to reducing sugar in aqueous media catalyzed by the cellulase enzyme system suffers from slow reaction rates due in large part to the highly crystalline structure of cellulose and inaccessibility of enzyme adsorption sites. ILs are a new class of non-volatile solvents that exhibit unique solvating properties.They can be tuned to dissolve a wide variety of compounds including cellulose. Because of their extremely low volatility, ILs are expected to have minimal environmental impact on air quality compared to most other volatile solvent systems. In this study, an attempt was made to disrupt the cellulose structure using the ionic liquid (IL), 1-allyl-3-methylimidazolium chloride ([AMIM]Cl),The cellulose samples without any pretreatment were readily dissolved in [AMIM]Cl.In a cellulose regeneration strategy which accelerated the subsequent hydrolysis reaction.One-factor-at-a-time(OFAT) experiment was carried out for the corn stover after ionic liquid([AMIM]Cl)pretreatment at 85℃and4h.Cellulose could be precipitated from the The ionic liquid([AMIM]Cl) by the addition of deionized water.Initial enzymatic hydrolysis rates were approximately 1.8-fold higher for regenerated cellulose as compared to dilute sulfuric acid pretreatment maize stover as measured by a soluble reducing sugar assay. The optimum values of the five factors were obtained which was cellulase loading of 20~30 FPU/g of substrate, substrate concentration of 60g/L (w/v), temperature of 45°C, pH of 4.8 and reaction time of 18~24 h.