Method for refining crude quinoline by continuous rectification

Abstract

The invention discloses a method for refining crude quinoline by continuous rectification. The method comprises the following working steps of: making the crude quinoline into a heavy component removing rectifying tower; removing heavy component impurities from the bottom of the tower; extracting steam from the top of the tower; transferring the steam into a heat exchanger; refluxing part of fluid which is condensed by using the heat exchanger; making the other part of the fluid which is condensed by using the heat exchanger enter a light component removing rectifying tower in a feeding form; vaporizing light component impurities from the liquid which enters the light component removing rectifying tower from the top of the tower; making part of a material flow enter the heat exchanger from the bottom of the tower; making the other part of the material flow enter a quinoline rectifying tower; and extracting a refined quinoline product from the top of the tower and extracting a crude isoquinoline product from the bottom of the tower from the material flow which enters the quinoline rectifying tower. In the method, the refined quinoline product with the purity of 99.5 percent is obtained by taking the crude quinoline separated from coal tar as a raw material, removing the heavy component impurities and the light component impurities by using the heavy component removing rectifying tower and the light component removing rectifying tower respectively, and refining by using the quinoline rectifying tower. The method has the advantages that: the method is simple and is easy to operate, the quality of a product is improved, and the energy source and the production cost are saved.

Description

technical field [0001] The present invention relates to a kind of method of refining crude quinoline, more specifically, the present invention relates to a kind of method of refining quinoline from crude quinoline. Background technique [0002] Quinoline is an important raw material for organic synthesis. It is used in the pharmaceutical industry to make niacin-based, 8-hydroxyquinoline-based and quinine-based drugs. And analgesics, etc.; it can also be used to produce dyes and photographic photosensitive pigment raw materials, rubber vulcanization accelerators, flotation agents, pickling corrosion inhibitors and pesticides. Due to the complex synthesis process of the synthetic method, the cost is expensive, and it cannot meet the needs of industrial growth. Existing quinoline is mainly derived from coal tar chemical industry, and the quinoline directly separated from coal tar has a low purity and cannot meet the needs of the pharmaceutical, dyestuff and rubber industries. ...

AI Technical Summary

Problems solved by technology

Among them, the phosphate method, the sulfate method and the hydrochloric acid-benzene countercurrent extraction method all have strong acids involved in the separation, which have high requirements on equipment performance, relatively complicated production technology, and generate waste water at the same time, increasing production costs; among them, azeotropic distillation Although the production of waste water is avoided, a large amount of entrainer is needed, and the entrainer is easy to remain in the quinoline product, which affects the quality of the product

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