纤维素酶酶解稻壳制备葡萄糖的工艺研究
在对稻壳进行提取葡萄糖进而发酵成乙醇的试验中，为了提高葡萄糖得率，我们先要从稻壳中提取出纤维素，破坏半纤维素及木质素的结构，所以先要进行实验准备步骤─预处理。预处理主要有四种方法，分别是高温高压、稀酸、稀碱和液氨。根据我国生产国情，环境限制，实验条件等种种因素，本实验采用稀酸预处理的方法。
纤维素酶酶解是从木质纤维原料提取出乙醇这整个实验过程中比较重要的一步。木质纤维原料组成中比重较多的是纤维素，其结构是十分紧密的，化学方法很难将其彻底水解且不破坏葡萄糖的结构，所以经过科学家们经年累月的研究发现纤维素酶是能够高效水解纤维素的一种物质。木质纤维原料中不仅含有难于水解的纤维素，而且还含有阻碍纤维素水解的木质素。木质素不仅有阻碍作用，它还会在实验后续的发展中生成有毒的产物，所以纤维素水解在整个试验中是最为重要的一步。本文着重对纤维素酶酶解反应影响的四种因素（缓冲溶液pH值，温度，酶用量，酶解时间）进行了详细的研究，寻求最为合适的实验条件，争取葡萄糖的得糖率最高。
毕业论文关键词：稻壳，纤维素酶，稀酸预处理，燃料乙醇
Abstract Energy is the prerequisite of human civilization and the important material base of economic growth and social development。As the most popular renewable clean energy─fuel ethanol, and its development trend has can't be held back。It has been an important task for all countries in the world to introduce the production of fuel ethanol into industrialization。At present, the country is mainly used the traditional corn, wheat and other grain starch or sugar cane juice for the production of industrial ethanol raw materials, but the cost of raw materials is too high, it is not very cost-effective。The use of food as a raw material is also a waste of land resources, but also limits the development and promotion of ethanol industrialization。Rice husk as a waste material, it also belongs to the wood fiber raw materials, renewable, clean resources。As a result, it is a lot of benefits for the production of fuel ethanol。In this way, it can avoid the atmospheric pollution and the destruction of the ecological environment caused by the burning of a large amount of straw in the field。 It is of great significance to the sustainable development of our country's economy and society。
In the extraction of glucose and fermented into ethanol test of rice husk, in order to improve the recovery of glucose, we first have to will rice husk cellulose extracted, the destruction of the structure of hemicellulose and lignin, so the first experimental preparation step is pretreatment。There are four main methods of pretreatment, respectively, high temperature and high pressure, dilute acid, dilute alkali and ammonia。According to China's national conditions of production, environmental restrictions, the experimental conditions of this experiment using dilute acid pretreatment method。
Cellulose hydrolysis is a key step in the production of ethanol from rice husk。Fibrous structure of wood fiber raw material composition is very close and chemical method is difficult to completely hydrolyzed and does not destroy the glucose structure, so after people for a long history of research found that cellulase is able to efficiently hydrolyze cellulose a substance。In the raw material of wood fiber, it is not only difficult to be hydrolyzed, but also lignin, which hinders the hydrolysis of cellulose。Lignin is not only hindered, it will produce toxic products in the development of experimental follow-up, so the hydrolysis of cellulose is the most important step in the whole test。This paper focuses on the cellulose hydrolysis of four factors (pH value of buffer solution, temperature, enzyme dosage, enzymolysis time) were studied in detail, seek the most appropriate experimental conditions, glucose for the sugar rate is the highest。
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