A method and system for ethanol production by industrial tail gas fermentation

Abstract

The main purpose of the present invention is to provide a method and system for producing ethanol by fermentation of industrial tail gas. The method includes: pretreating the industrial tail gas, and the pretreatment includes: removing toxic substances in the industrial tail gas to obtain purified tail gas ; using the purified tail gas for fermentation to obtain fermented mature mash and residual gas; distilling the fermented mature mash to obtain ethanol and bacteria-containing residual water; separating and concentrating the bacteria-containing residual water to obtain a dope and clear liquid; purify the clear liquid; carry out tail gas treatment on the residual gas to remove residual CO. The method of the invention realizes the optimization and organic combination of the whole system process, has high ethanol yield and purity, effectively purifies the discharged sewage and tail gas, effectively utilizes raw materials, and realizes the recycling of materials and energy in the whole system.

Description

technical field [0001] The invention belongs to the technical field of tail gas recovery, and in particular relates to a method and system for producing ethanol by fermentation of industrial tail gas. Background technique [0002] The traditional fuel ethanol production process mostly uses corn, wheat, cassava, etc. as raw materials, and produces ethanol through yeast fermentation. At present, many fuel ethanol enterprises in China have adopted this production process, but this process uses grain and crops as raw materials. The cost is high; at the same time, as a country with a large population and a small area of ​​cultivated land per capita, China uses a large number of grain crops as raw materials to produce ethanol, which has food security problems, and it is difficult to solve the development problem of "not competing with others for food and land". Gas fermentation using industrial tail gas as raw material uses CO as a carbon source and uses bacterial fermentation to ...

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Problems solved by technology

However, the ethanol production process of industrial tail gas fermentation also has problems such as low ethanol concentration in the fermentation liquid, bacterial protein denaturation by heat, easy to block the distillation tray, and high COD and BOD content in the sewage; moreover, the fermentation tail gas still contains a small amount of CO, which cannot be discharged directly into the air

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