Method for producing high-concentration ethanol by mixed fermentation of starch and molasses

Abstract

The invention discloses a method for producing high-concentration ethanol by the mixed fermentation of starch and molasses which are used as raw materials. The method comprises the following steps of: adding water to the raw material of starch and stirring to constant volume, liquefying at low temperature and simultaneously fermenting and saccharifying, and then adding the raw material of molasses for mixed fermentation through the batch or continuous flow feeding supplement way. The mixing ratio of the raw materials of starch and molasses is 1:2-8:1 (W / V), the temperature of fermentation is 30-37 DEG C, the time of fermentation lasts for 40-48h, the percentage of ethanol yield is 12.43-16.67% (V / V). The invention changes the traditional single raw material fermentation way, and not only improves the total sugar concentration of the fermented mash, but also reduces the viscosity of starch raw mash and improves the liquidity, so the concentration of ethanol in the fermentation mash is increased, and the raw material utilization rate is improved, and ethanol distillation energy consumption and production cost are decreased, the amount of sewage discharge is reduced, the load of sewage treatment is lowered and the ethanol production process is more economical and environmentally friendly.

Description

Technical field

[0001] The present invention relates to the technical field of biological fermentation engineering, in particular to a method for fermenting high-concentration ethanol with starch and molasses mixed raw materials. Background technique

[0002] The raw materials used in the production of ethanol and fuel ethanol in the prior art are basically a single raw material. For example, starch raw materials and molasses are common raw materials for ethanol production by fermentation. When starchy raw materials are used for thick mash fermentation, there are disadvantages of high solids concentration and poor fluidity, and precipitation is prone to occur, which is not conducive to continuous fermentation in large tanks, and is also not conducive to indirect heating of the reboiler of the mash tower during distillation. The waste grains are not easy to handle because of the high concentration of COD. Molasses contains 512% colloidal substances composed of pectin, caramel and...