Improvement Of Ethanol Fermentation Technology Of Immobilized Yeast

Alcohol was a renewable resource,which was the largest and most widely used product in biotechnology products in the world today.The use of alcohol to replace part of the oil had great significance,Not only it could reduce the amount of foreign exchange which was used to buy oil,It could also reduce greenhouse gas emissions.At present,alcohol production had risen to a high level of national energy security,the use of renewable resources,such as starch,fiber raw materials,could ensure the supply of alcohol and improve the enthusiasm of farmers.China had become a big country in alcohol production,but there were many problems in the process of alcohol production,such as low fermentation strength,high production cost,high energy consumption and so on.Now researchers had developed immobilization technique,high concentration fermentation technology in order to improving the efficiency of alcohol production,on this basis,combined with the actual production conditions of Tianguan Group,this paper carried out research on the production process of producing alcohol by fermentation with immobilized yeast.The conclusions of this study were as follows:1.Using shake flask fermentation,By optimizing the process of immobilization,Comparison between the best immobilization process and the traditional process,The results showed that the ethanol content of the immobilized yeast was 1.3% and2.8% higher than that of the embedding method and the traditional process respectively,The immobilized yeast was selected for 9 batch continuous fermentation experiment,The average starch utilization rate was 89.269%,the average acid production was 2.244,the average alcohol content was 13.453%,and the average residual sugar was 1.008%,The result of fermentation was ideal.2.Using 600 L fermentation tank was carried out immobilized yeast fermentation,The optimum process conditions were determined as follows: initial sugar concentration was20%,fermentation temperature was 35,pH was 4.5,fermentation time was 84 h,carrier loading was 8 g/L,and circulation volume was 2 BV.Under this condition,the utilization rateof starch was 85.078%,the consumption of grain was 2.985(t/t),the alcohol content is14.31%.In the further study,the influence of nitric acid instead of sulfuric acid,no-load time and carrier recycle on fermentation was studied,and carrier stability.The results showed that the use of nitric acid instead of sulfuric acid,no-load time in short time,repeated use of carrier had no significant effect on the fermentation results,and the immobilized material was durable,suitable for long-term use of large production..3.The economic benefit evaluation was carried out on the 600 L tank.After calculation,the ethanol production by immobilized yeast could save 222.7 yuan in production cost,so that it could generate 248 yuan / ton profit.In addition,immobilized yeast fermentation could increase the economic benefit of ethanol production enterprises by 26 thousand and511 yuan per year due to the increase of single tank starch utilization and the increase of batch fermentation.It had contributed significantly to the sustainable development of alcohol production enterprises,with obvious economic benefits.4.This study explored the preparation of immobilized yeast.On this basis,600 L continuous fermentation test was carried out.The optimum fermentation process and production cost of immobilized yeast were explored.It was proved that the immobilized yeast could increase the economic benefit for the alcohol production enterprises.This study provides a reference for alcohol production enterprises to reduce the intensity of seed culture,improve production efficiency and increase economic efficiency.