Novel rectification method

Abstract

Provided is a novel rectification method. The method comprises a dehydration process and a product refining process, and the method is suitable for the components that no azeotropy or association exists between two components and is used for solving the problems that a product is prone to thermal decomposition and low in purity in the rectification process of the substances. The method comprises the steps that a waste fluid containing a low-concentration product is pumped into a dehydrating tower, and the waste fluid in a tower kettle of the dehydrating tower is heated to be steam and then condensed into a fluid on the tower top to enter a first reflux tank; the fluid in the tower kettle of the dehydrating tower enters a product tower, and the fluid in a tower kettle of the product tower is heated to be steam and then condensed into a fluid on the tower top to enter a second reflux tank; the fluid in the tower kettle of the product tower enters a product refining tower, the fluid in a tower kettle of the product refining tower is heated to be steam and then condensed into a fluid on the tower top to enter a third reflux tank, and a qualified product is obtained from a liquid phase at the rectifying section of the product refining tower.

Description

technical field [0001] The invention relates to a novel rectification method, which belongs to the field of separation and purification of substances. Background technique [0002] DMAC / DMF / DMSO (dimethylacetamide / N,N-dimethylformyl / dimethyl sulfoxide), can dissolve a variety of compounds, can be completely miscible with water, ether, ketone, ester, etc., has thermal It is characterized by high stability, low hydrolysis and low corrosion, and is widely used in petroleum processing and organic synthesis industries. Taking DMAC as an example, DMAC has good solubility for various resins, especially polyurethane resin and polyimide resin, and is mainly used as a solvent for heat-resistant synthetic fibers, plastic films, coatings, medicines, and acrylonitrile spinning. In organic synthesis, DMAC is an excellent catalyst, which can accelerate reactions such as cyclization, halogenation, cyanation, alkylation and dehydrogenation, and can increase the yield of main products. In t...

AI Technical Summary

Problems solved by technology

However, in the process of production and use, a large amount of waste water containing DMAC is produced, and direct discharge will have a great impact on the water quality environment and endanger people's health. Therefore, the recovery and treatment of DMAC waste liquid is very important for environmental protection and reduction of production costs of enterprises. are of great significance

[0003] In the traditional process, the removal of moisture can be designed as a one-tower process, but if the moisture content in the raw material is high, if you want to obtain qualified DMAC / DMF / DMSO products, you need to increase the reflux ratio appropriately when the entire process extracts moisture, and The latent heat of vaporization of water is relatively large. When the reflux ratio is increased, the energy consumption will increase accordingly.

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