Research In Pretreatment Of Lignocellulose And Improving The Efficiency Of Enzymatic Hydrolysis

Bio-refining technology which looks lignocellulose as raw materials is a effective way to solve the problems of resources or environment. During the process of enzymatic hydrolysis of lignocellulosic biomass, incompleted pretreatment, low efficiency and high cost is a major limiting factor. Looking for green and efficient pretreatment methods, improving the efficiency of enzymatic hydrolysis will have an important significance to the sustainable development of human society. In this papers, corn stalks as the experimental materials, studied the effect of the acidic electrolyzed water on the corn stalk's hemicellulose degradation. And discussed Enzymatic hydrolysis of pretreated straw to explore the role of the external field by adding the reaction or response factor additives on the enzymatic hydrolysis were investigated their efficiency.The acidic electrolyzed water have acid and strong oxidizing. Pretreatment of lignocellulosic raw materials with it after the removal of hemicellulose than with the pH value of the HCL, H₂SO₄ were significantly increased. Best pre-conditions:pH = 2.0, reaction of liquid to solid ratio30:1, 180℃10min, under these conditions, pretreatment of corn stover's hemicellulose removal rate is 92.1%.Ultrasound is a typical role of the external field. Ultrasound can improve the enzymatic hydrolysis was found that the rate. Best supporting conditions:Ultrasonic power 300W, ultrasound time / interval time 5s/10s, ultrasonic frequency of 20 times each.Under these conditions, over 72h, the yield of enzymatic hydrolysis is 86.45%, the biggest yield of enzymatic hydrolysis process can be increased by 20.3%. Reaction promoter is commonly used surfactants. Ionic surfactants inhibites the hydrolysis rate, non-ionic surfactants can improves the hydrolysis rate. The best conditions of PEG assisted hydrolysis is: Select PEG20000, concentration of 0.05g/g, hydrolysis 48h. Under these conditions, enzymatic hydrolysis yield reached 85.83%, 15.66% increase compared to the control. Tween20, Tween80 concentration are 0.06g/g, 0.05g/g, the enzyme yield reached the maximum74.93%, 75.98%, compared with the control, respectively increase 9.93% and 10.98%.Metal ions is the reaction factor, Ca²⁺,Mg²⁺,Zn²⁺ improve the hydrolysis rate, Na⁺,K⁺,Fe²⁺,Fe³⁺ inhibite the hydrolysis rate. The optimal concentration of Ca²⁺,Mg²⁺,Zn²⁺ are 1.0mg/mL,2.5mg/mL,3.0mg/mL, Corresponding Enzymatic hydrolysis are 73.94%, 72.29%, 70.68%. Compared to the control, respectively increase 8.94%,7.29%,5.68%。...