A method for producing butanol by fermenting lignocellulosic raw materials

Abstract

The invention discloses a method for producing butyl alcohol through fermenting by utilizing a lignocellulose raw material. The method comprises the following steps: (1) pre-treating the lignocellulose raw material; (2) adopting Aspergillus niger T2 for performing enzymatic hydrolysis on the pre-treated raw material, thereby acquiring a hydrolyzed mixed liquid glucose of cellulose and hemicellulose, wherein the Aspergillus niger is the Aspergillus niger T2 said in patent CN 200910011768.8; (3) utilizing calcium hydroxide to perform detoxification treatment on the hydrolyzed mixed liquid glucose; (4) taking the detoxified liquid glucose as a carbon source, replenishing nutrient elements and preparing a fermenting culture medium; and (5) inoculating Clostridium beijerinckii XH0906 into the fermenting culture medium, fermenting and preparing butyl alcohol. The Clostridium beijerinckii XH0906 has been preserved at China General Microbiological Culture Collection Center on May 04, 2014 and the preservation No. is CGMCC No.9124. According to the method disclosed by the invention, the Aspergillus niger is utilized to perform enzymatic hydrolysis on the cellulose and the hemicelluloses, the xylose and glucose in the hydrolysate are utilized to ferment and produce butyl alcohol and the method has the characteristics of good enzymatic hydrolysis effect, high fermentation yield, and the like.

Description

technical field [0001] The invention belongs to the technical field of biological fermentation, and in particular relates to a method for producing butanol by fermenting lignocellulosic raw materials. Background technique [0002] Butanol is an important organic chemical raw material, which is widely used in chemical, pharmaceutical and petroleum industries. And because there are two more methylene groups than ethanol, butanol has higher hydrophobicity and lower volatility, can be mixed with gasoline in any proportion, and has a calorific value equivalent to gasoline. As a potential renewable bioenergy that can replace gasoline, butanol has attracted more and more attention from all over the world. [0003] With the increasing depletion of petroleum resources, reducing the proportion of fossil energy use and strengthening the development of renewable energy has become an important trend of human energy utilization in the future. Moreover, butanol produced by the propylene ...

AI Technical Summary

Problems solved by technology

However, the following problems generally exist in the traditional acetone-butanol fermentation: (1) The traditional acetone-butanol fermentation strain needs to be cultivated and fermented under strict anaerobic conditions. If the operation is not careful, it is easy to enter the air, causing the bacteria to not grow normally. Therefore, it is usually necessary to pass inert gas such as N during the fermentation process. 2 (2) The yield of butanol is low, only about 20% (mass fraction), which makes the cost of raw materials in the butanol fermentation process relatively high, which restricts the development of the butanol fermentation industry; (3) ) Fermentation products have 40% by-products such as acetone and ethanol in addition to butanol, which consume limited carbon metabolic flow, reduce the proportion of butanol in the product, increase the difficulty of recovering butanol, and increase energy consumption

[0009] However, the acetone-butanol fermentation strain has a repressive effect on sugar metabolism, that is, it will preferentially utilize glucose in the presence of glucose, and other sugars such as xylose are hardly consumed

At the same time, the efficiency of Clostridium acetobutylicum in utilizing xylose metabolism is also low, and the rate of utilizing xylose for fermentation is much lower than that of glucose fermentation.