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 obtaining an enzymatic product through fermentation, 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 part of the product of steam explosion with the enzyme first to obtain a mixture and then continuously adding the rest production of the steam explosion into the mixture for mixing, wherein the rest product of the steam explosion is added at a speed that keeps the concentration of the product of the steam explosion in the reaction system no more than 150g / L and the weight of the part, mixed with the enzyme first, of the product of the steam explosion accounts for 10 to 30 percent of the total weight of the product of the steam explosion. The method can improve the ethanol yield greatly.

Description

technical field [0001] The present invention relates to a method for producing ethanol, and more particularly, to a method for producing ethanol from cellulose-containing raw materials. Background technique [0002] In the prior art, ethanol can be produced from raw materials containing cellulose, which are generally roots, stems and leaves of plants, including straw. The straw refers to the remaining roots, stems and leaves of crops (generally herbaceous plants) after harvesting seeds or fruits, mainly stems and leaves, such as corn straw, sorghum straw, rice straw, wheat straw and other cereal plants, including bean Straw oil plant straw and cotton straw. Cellulose, hemicellulose and lignin in the straw are closely combined through covalent bonds and / or non-covalent bonds, and the three account for about 70-90% by weight of the total weight of the dry matter of the straw. The respective contents of cellulose, hemicellulose and lignin in straw will vary with different sou...

AI Technical Summary

Problems solved by technology

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 will still be 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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