湿氧化爆破法处理木质纤维素的降解动力学的研究及评价

项目名称： 湿氧化爆破法处理木质纤维素的降解动力学的研究及评价

项目编号： No.21076114

项目类型： 面上项目

立项/批准年度： 2011

项目学科： 轻工业、手工业

项目作者： 龚大春

作者单位： 三峡大学

项目金额： 12万元

中文摘要： 本项目以木屑、switch grass(美国能源草)、玉米秸秆、油菜秸秆等为原料研究证实，湿氧化爆破法是一种将湿氧化法与传统的蒸汽爆破集成在同一反应器中协同作用预处理木质纤维素的新方法。该方法可以弥补蒸汽爆破法对木质素去除效果差，有效去除木质素和半纤维素，提高纤维素的酶解效率，在纤维质能源化工领域具有巨大的应用前景。本项目利用GC-MS、HPLC等手段，在完善湿氧化爆破的耦合工艺的基础上，以所设计的湿氧化爆破降解过程的动力学模型为依据，开展木质纤维素的湿氧化爆破降解过程的表观动力学以及酚类（4-羟基苯甲醛、紫丁香醛）、呋喃类（糠醛和5-甲基糠醛）和羧酸类（乙酸）等特殊小分子的生成动力学规律的研究，并对纤维素的酶水解效果和液体部分副产物对微生物细胞生化特性的影响等方面进行评价。酚类物质生成速度与可溶木质素的浓度和氧气分压成正比，紫丁香醛生成速率常数是4-羟基苯甲醛快10倍；糠醛的生成动力学常数是5-甲基糠醛的2倍左右，分解为羧酸速率基本相同，但比酚类物质生成为羧酸速度慢；在微碱性条件下，湿氧化爆破反应中的可溶性木质素比可溶性半纤维素更容易降解为乙酸，乙酸浓度最高可达17.5g/L

中文关键词： 木质纤维素；湿氧化爆破；动力学；分子机理；评价

英文摘要： It was found that wet-explosion method is novel for pretreatment of lignocellulose cooperation bycombining the wet-oxidation with the conventional steam-explosion in the same reactor using wood chip,the swich grass (American energy grass),corn straw, rape straw as feedstocks. The method can simultaneously remove lignin and hemicellulose with improving the lignin separation effect, decreasing the reaction temperature and pressure and increasing the cellulose enzymatic efficiency. The method has great prospect in the field of energy chemisty and bioprocess of lignincellulose. The project will mainly research the decomposed dynamics of lignocellulose in the wet-explosin process and the chemical kinetics of the special small molecule chemistry such as phenols,furans, carboxylic acids,and evaluate the enzymatic efficiency of cellulose and the effect of the byproduct on the biological characterization of the microbe cell. The formation speed of phenols is proportional to the soluble lignin concentration and the fraction pressure of oxygen;the formation rate constant of syringaldehyde is ten times faster than the 4-hydroxy benaldehyde;the rate constant of furfural is two times faster than the hydroxymethyl fufural and their decomposion rate to carboxylic acid is the same, slower than the phenols decomposion; the soluble lignin is easier to be decomposed than the solube hemicellulose to acetic acid and the acetic acid concentration is up to 17.5g/L.

英文关键词： lignocellulose;wet-explosion;degration dynamics;molecular mechanics;evaluation