Novel energy-saving three-tower continuous extractive distillation technology and extractive distillation system thereof

Abstract

The invention relates to a novel energy-saving three-tower continuous extractive distillation technology and an extractive distillation system thereof. The novel energy-saving three-tower continuous extractive distillation technology comprises the steps as follows: a preheated azeotrope system enters a tower body, a preheated extracting agent enters an extractive distillation tower body, raw materials enter the tower body from the tower bottom, infinite reflux operation is performed, a high-purity and light-component product is produced from the tower top, a tower bottom produced liquid enters an extracting agent recovery tower from a sixth tower plate of the extracting agent recovery tower, infinite reflux operation is performed, a high-purity extracting agent is produced from the tower bottom and mixed with a fresh extracting agent and enters the extractive distillation tower, a tower top produced liquid enters an azeotropic distillation tower, infinite reflux operation is performed for one hour, a heavy-component product is produced from the tower bottom, the tower top produced liquid circularly returns to an azeotrope feeding pipe of the extractive distillation tower, is mixed with the raw materials and enters the extractive distillation tower, and production is performed continuously. The novel energy-saving three-tower continuous extractive distillation technology and the extractive distillation system thereof have the advantages of simple technological process, easiness in operation, little investment, high efficiency, short construction period, consumption reduction, remarkable energy saving and obvious increase of azeotrope light-component productivity.

Description

technical field [0001] The invention relates to a novel energy-saving three-tower continuous extraction and rectification process and an extraction and rectification system thereof, belonging to the field of chemical technology. Background technique [0002] The structural formula of ethanol is CH 3 CH 2 OH, commonly known as alcohol, is a flammable and volatile colorless transparent liquid at normal temperature and pressure. Ethanol is one of the industrial raw materials with a wide range of uses and a large amount. It occupies an important position in various sectors of the national economy and has a close relationship with people's lives. Ethanol is widely used in food, chemical, pharmaceutical, dye, national defense and other industries, and it is also a very important clean energy. And the ethanol-water system is the system with the lowest azeotropic point. [0003] At present, the separation methods of ethanol-water azeotropic mixture mainly include extractive dist...

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Problems solved by technology

[0006] When the extraction and rectification extractant used in extractive distillation, its gas-liquid equilibrium composition diagram and the gas-liquid equilibrium composition diagram without extractant show a special phenomenon, that is, taking ethanol-water azeotropic system as an example, for ethanol-water In the water binary system, ethylene glycol significantly increases the relative volatility of the two near the middle and high concentrations, but in the low concentration area, ethylene glycol makes the relative volatility of ethanol-water decrease significantly

In this way, if the general double-tower extractive distillation is used, excessive energy consumption will be caused, resulting in waste

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