Production method of cellulose ethanol

Abstract

The invention discloses a production method of cellulose ethanol, which comprises the following steps of: (1) adding a culture medium containing the raw materials of cellulose and / or hemicellulose into a fermentation reaction kettle; (2) adding cellulase into the fermentation reaction kettle and inoculating Candidalusitaniae; and (3) carrying out synchronous diastatic fermentation under the combined action of the cellulase and the Candidalusitaniae and separating to obtain the cellulose ethanol. The Candidalusitaniae used for the synchronous diastatic fermentation in the invention has higher ethanol tolerance and higher ethanol throughput rate and can prepare the cellulose ethanol by the synchronous diastatic fermentation with high efficiency through taking the cellulose and the hemicellulose as the raw materials under the combined action of the cellulase.

Description

technical field [0001] The invention relates to the technical field of bioenergy development, in particular to a production method of cellulosic ethanol. Background technique [0002] With the depletion of petroleum resources, the rise of petroleum prices and the deterioration of the environment, it has become a research hotspot in the field of industrial biotechnology to find new renewable resources to replace fossil resources and to develop clean energy. The development of biomass energy can alleviate the dependence on petroleum resources, control carbon dioxide emissions, and promote the development of new agricultural industrial chains, which is of great significance to promote the construction of new socialist countryside in our country. [0003] As a renewable and clean energy, fuel ethanol has been implemented in the United States and Brazil since the 1970s. my country's ethanol production capacity has reached more than 5 million tons per year, of which the annual ou...

AI Technical Summary

Problems solved by technology

Cellobiose inhibits endoglucanase and exoglucanase, hinders the rate and yield of the entire ethanol in the simultaneous saccharification and fermentation process, and requires a large amount of expensive β-glucosidase supplementation, resulting in Process cost is very high

On the other hand, yeasts that ferment cellobiose have been found, but their tolerance to alcohol is very low

[0007] Second, the simultaneous saccharification and fermentation technology cannot guarantee the coordination and unity of the enzymatic hydrolysis temperature and fermentation temperature

Generally, the enzymatic hydrolysis temperature is 40-50°C, while the fermentation temperature of Saccharomyces cerevisiae is 28-35°C, so the process can only be compromised, resulting in excessive enzyme or yeast usage, and the simultaneous saccharification and fermentation time is generally longer More than 100 hours, the fermentation efficiency is low

The third is that under the condition of high substrate content, a large amount of cellulose is not converted, the enzymolysis effect is significantly reduced, and the productive rate of ethanol is also very low, generally only reaching 3-5% (v / v)

[0008] At present, the fermentation production rate and yield of ethanol cannot meet the requirements of simultaneous saccharification process, and it is not economical

Domestic patent (CN 101130792A) reports a method for preparing fuel ethanol by enzymatically decomposing stalks, the fermentation time is 10-15 days, the enzymolysis efficiency is very low, and there is no economic feasibility for industrialization

Another domestic patent (CN101270372A) reports a method for concentrating sugar liquid in cellulose ethanol fermentation liquid, the purpose is also to solve the problem of low sugar concentration after enzymatic hydrolysis, which shows that the current enzymatic hydrolysis technology cannot meet the requirements of industrialization

Although the concentrated patented technology can change the concentration of enzymatically hydrolyzed sugar, the problem of low enzymolysis rate of cellulose has not been solved, which will lead to low utilization rate of raw materials and high production cost.

Patent CN 101230359 reports a cellulose ethanol process using a modified polydimethylsiloxane polymer membrane to enrich the concentration. The problem of low fermentation efficiency

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