Method for preparing ethanol by using raw material containing cellulose

Abstract

The invention discloses a method for preparing ethanol by using a raw material containing cellulose, which comprises the steps of subjecting the raw material containing cellulose to steam explosion, mixing an obtained product of the steam explosion with an enzyme for enzymolysis, and fermenting the obtained enzymatic product, wherein a method for the steam explosion of the raw material containing cellulose comprises the steps of continuously delivering the raw material containing cellulose to a heat-preservation pressure unit, keeping the raw material containing cellulose in the heat-preservation pressure unit for 3 to 10 minutes and then releasing part of the raw material containing cellulose in the heat-preservation pressure unit to normal pressure every other 5 to 12 seconds; and a method for mixing the product of the steam explosion and the enzyme comprises the step of mixing the product of the steam explosion with the enzyme in batches, wherein the batches are at least two batches, and in each batch, the additive amount of the product of the steam explosion accounts for 60 percent of the total weight of the product of explosion at most. The method of the invention can effectively improve the sugar conversion rate of the raw material, thereby greatly improving ethanol yield.

Description

technical field [0001] The present invention relates to a process for the production of ethanol, and more particularly to a process for producing ethanol from cellulose-containing raw materials. Background technique [0002] The prior art method for producing ethanol from cellulose-containing raw materials, such as straw, mainly includes three steps: 1. pretreatment of cellulose-containing raw materials, 2. enzymatic hydrolysis of cellulose; 3. fermentation of sugar to produce ethanol. [0003] Cellulose-containing raw materials are generally roots, stems and leaves of plants, including straw. The stalks are the roots, stems and leaves left after harvesting fruits of crops (generally herbaceous plants), mainly stems and leaves, such as corn stalks, sorghum stalks, wheat straws and other cereal plant stalks. The main component of straw is lignocellulose. The lignocellulose is a mixture of cellulose, hemicellulose and lignin, and the cellulose, hemicellulose and lignin are c...

AI Technical Summary

Problems solved by technology

[0014] The purpose of the present invention is to overcome the defects of the low yield of ethanol in the existing method for preparing ethanol from cellulose-containing raw materials, and provide a method for preparing ethanol using cellulose-containing raw materials with higher ethanol yield

The presumed reason may be that due to the large amount of cellulose-containing raw materials put into the steam explosion device in each batch, and the difference in the accumulation mode of each batch of raw materials or the instability of steam explosion conditions, it is impossible to ensure that all the cellulose-containing raw materials The cellulose raw material fully absorbs the water vapor within a few minutes after being steamed, so there are still most of the cellulose-containing raw materials that cannot be completely exploded by the water vapor inside because they cannot fully absorb the water vapor. As a result, the lignin sheath embedding cellulose and hemicellulose in the cellulose-containing raw material cannot be fully destroyed, reducing the proportion of cellulose in the cellulose-containing raw material that can be contacted with enzymes, thereby reducing the yield of ethanol

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