Method for producing ethanol fuel by using sweet sorghum stalks

Abstract

The invention discloses a method for producing ethanol fuel by using sweet sorghum stalks. The method mainly comprises the following steps of: freezing and storing the sweet sorghum stalks and then unfreezing the sweet sorghum stalks, pressing the sweet sorghum stalks to extract juice, concentrating the juice, performing pre-fermentation and liquid fermentation on the concentrate, reclaiming yeast during fermentation, and performing ethanol distillation and dehydration on the fermented product to obtain the ethanol fuel. The integration technology meeting the industrialized requirement is finally realized by the method, each ton of ethanol prepared by solid fermentation consumes 18 tons of stalks, the fermentation time of 48 to 72 hours, the power of 420kWh, and the steam of 6.5 tons. Compared with the prior art, the stalks consumed by each ton of ethanol are reduced by 2.47 tons, the power consumption is reduced by 172kWh, and the steam consumption is reduced by 3.15 tons. The method finally reaches the indexes of stalk consumption of 15.53t power consumption of 248kWh and steam consumption of 3.35t for each ton of ethanol,, breaks through the difficulty in the prior art by research, development and experiment, and finally implements the step of extracting the juice from the sweet sorghum stalks by a pressing method with high yield, low water addition and low energy consumption.

Description

technical field [0001] The invention relates to a method for producing fuel ethanol, in particular to a method for producing fuel ethanol by utilizing sweet sorghum stalks. Background technique [0002] The existing method for producing fuel ethanol mainly utilizes sweet sorghum for solid-state fermentation production. The technology of producing fuel ethanol from sweet sorghum stalks by solid-state method is a technology that directly uses sweet sorghum stalks to ferment and produce fuel ethanol without extracting juice. Therefore, the annual production period of the factory is only two months from harvest to freezing. However, the fermentation equipment of the sweet sorghum stalk fermentation process of the solid-state method is complicated. The main reason is that the solid-state method cannot be stirred by an ordinary agitator, so it is necessary to use an inclined drum solid-state fermentation tank system that requires a lot of power. Because this system Power is used...

AI Technical Summary

Problems solved by technology

Concentrated pressing of raw materials will lead to low utilization rate of equipment, resulting in excessive investment and no economic benefits; prolonging the harvest period will greatly reduce the sugar content of raw materials, and the unit consumption of raw materials will increase.

[0004] Fermentation is a key step in the production of fuel ethanol. It directly determines various important indicators such as raw material consumption per ton of ethanol, utilization rate of fermentation equipment, investment in fermentation equipment, energy consumption required for later distillation, and wastewater discharge at the bottom of the tower. Especially in our In this process, because the syrup needs to be concentrated and stored, it needs to be re-diluted when it is fermented. If the concentration of fermented ethanol is too low, the concentration of sugar juice required will inevitably be low, and the amount of water added for dilution will increase, thereby increasing the investment in fermentation and distillation equipment. It also increases the energy consumption and sewage discharge of the distillation, so increasing the ethanol concentration in the fermented mash has become an important factor in determining the production cost and equipment investment. According to the conventional fermentation method, 12.5% ​​(v / v) alcohol content is the concentration For mash fermentation, if the concentration of fermented ethanol is too high, the total residual sugar will be too high, that is, the raw material consumption per ton of ethanol will be too high, and the fermentation time will be too long and the investment in equipment will be too large. Sugar consumption, short fermentation time, such a process is difficult to achieve with conventional fermentation methods

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