Study On The Preparation Of Fuel Ethanol From Lignocellulose Under Bio-degradation With Ultrasonic

Energy is an important momentum to the development of our society. Along with the exhaustion of fossil fuel, new energy exploitation becomes extremely urgent. Because of the advantages of biomass energy like broad distribution, tremendous reserves, high-speed regeneration, it will replace the fossil energy and become the dominant part of chemical technology in the future.Producing fuel ethanol with lignocellulose is the key point of biomass utilization. The aim of this technology is producing ethanol with waste cellulose material such as straw, cellulose garbage, and waste paper. Lignocellulose is a kind of compact material which mainly composed by cellulose, hemicellulose and lignose. This material must be degradation to monosaccharide before fermentation. Bio-degradation is the most promising technology of cellulose degradation as its advantage of low energy and low pollution. The production of fuel ethanol was studied in this paper with bio-degradation technology and the factor analysis.The microcosmic cavitation of ultrasonic can change the structure of materials and accelerate the mass transfer. The effect of ultrasonic to pretreatment was studied in this paper. Compared to other pretreatment technologies, alkali pretreatment cooperate with ultrasonic was considered to be the best way. The conditions of alkali pretreatment were weakened and the result was better when using ultrasonic. In addition, alkali pretreatment can doff the lignose effectively; meanwhile keep the most part of cellulose and hemicellulose. With this pretreatment technology, the resolution ratio of raw material is 24.1%; loss rate of cellulose and hemicellulose is 7% and 14.8% respectively; the doff rate of lignose is 43.3%; the saccharification rate of pretreated material is 45.6% after 48 hour's cellulase catalysis.In this paper, the cellulase,β-glucosidase,α-amylase and pentopan were used to compose the multi-enzyme. The multi-enzyme was employed to catalyze the alkali pretreated material. The optimal condition of multi-enzyme catalysis is: 55℃, pH 6.0, 180 rpm, 48 h; the dosage of enzyme is 1%; 80 W, 20 KHz ultrasonic was used to assist the enzyme catalysis. Compared to the simplex enzyme catalysis, the catalytical efficiency is enhanced from 22.8% to 68.5% and the technology is predigested. The experiment proved that, to decompose the lignocellulose, theβ-glucosidase and pentopan can enhance the efficiency of cellulase; ultrasonic also shows great effect on enzyme catalysis. Under 80 W ultrasonic wave, the catalytical efficiency of cellulase was increased by 70%.The yeast was used to ferment the sugar which produced by saccharification. The optimal technology: inoculate dosage is 5%, concentration of reducing sugar is 10%, ferment 12 hours. By the technology which studied in this paper, the total fuel ethanol yield rate is 11.9%.