Process and system for producing fuel ethanol by distilling low-concentration fermented mash using double-coarse single-fine distillation triple-tower

Abstract

The invention discloses a process for producing fuel ethanol by distilling low-concentration fermented mash using a double-coarse single-fine distillation triple-tower. The process comprises the following steps: (1) preheating mature fermented mash with the concentration of below 8% (v / v) to 65 DEG C through a mash preheater, feeding at the top of a degassing section, enabling a part of the fermented mash without gas to flow into a negative-pressure mash tower, preheating the rest of the fermented mash through a normal-pressure mash tower feeding preheater, and feeding the pre-heated fermentedmash into the top of a normal-pressure mash tower; (2) enabling wine steam in the normal-pressure mash tower to move upward to enter a negative-pressure mash tower reboiler to heat the negative-pressure mash tower, and conveying condensed crude alcohol into a crude wine tank; (3) preheating the crude alcohol in the crude wine tank, feeding the preheated crude alcohol into the lower part of a rectifying tower, and feeding alcohol steam above 95% (v / v) of the rectifying tower into a membrane dehydration device through an alcohol gas superheater for dehydration; and (4) enabling fuel ethanol steam dehydrated by the membrane dehydration device to enter a normal-pressure mash tower reboiler II to heat the normal-pressure mash tower, condensing and cooling to obtain a fuel ethanol finished product. Process equipment is simple, raw material cost is low, and energy conservation, consumption reduction and emission reduction are achieved.

Description

technical field [0001] The invention relates to the technical field of ethanol production, in particular to a process and a system for producing fuel ethanol by distilling low-concentration fermented mash with double crude and single refined three towers. Background technique [0002] At present, domestic fuel ethanol raw materials are mainly corn or cassava, and the alcohol concentration of its fermented mash can generally reach more than 12%. The alcohol concentration of fermented mash can reach more than 18%. High-concentration fermentation mash has laid a solid foundation for energy saving and consumption reduction in fuel ethanol production, so the current distillation process and distillation equipment are mainly aimed at the production of fuel ethanol from high-concentration fermentation mash. [0003] At present, in order to achieve energy saving, consumption reduction and emission reduction, research on the production of fuel ethanol using straw and steel industry ...

AI Technical Summary

Problems solved by technology

The alcohol concentration of the fermented mash used to produce fuel ethanol from straw and iron and steel industry waste gas is relatively low. Generally, the alcohol concentration of fermented mash is about 5%. At present, there is no distillation process and distillation for the production of fuel ethanol from straw and steel industry exhaust gas equipment, and the current distillation process and distillation equipment are complex and costly, mainly for the production of fuel ethanol with high-concentration fermented mash, if it is applied to the production of fuel ethanol with low-concentration fermented mash, it does not meet the purpose of energy saving and consumption reduction

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