Method and system for producing ethanol through fermentation of industrial tail gas

Abstract

A main propose of the invention is to provide a method and a system for producing ethanol through fermentation of industrial tail gas. The method includes the steps of: 1) pre-treating the industrial tail gas by removing toxic substances in the industrial tail gas to obtain purified tail gas; 2) fermenting the purified tail gas to obtain fermented mature mash and residual gas; 3) distilling the fermented mature mash to prepare ethanol and bacterium-containing residual water; 4) separating and concentrating the bacterium-containing residual water to obtain a concentrated liquid and a clear liquid; 5) purifying the clear liquid; and 6) performing tail gas treatment to the residual gas to remove residual CO. The method achieves optimization and organic combination of processes in the whole system and is high in yield and purity in the produced ethanol, effectively purifies discharged wastewater and tail gas, effectively utilizes the raw materials and achieves circulation utilization of substances and energy of 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 ...

AI Technical Summary

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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