Separation method of 2-methylpyridine

Abstract

The invention discloses a method for separating 2-methylpyridine. The method comprises the following steps: selecting a modulation agent M, wherein the modulation agent is a non-polar substance; the boiling point of the modulating agent is 130-183 DEG C; adding the modulating agent M into a separation raw material of a 2-methylpyridine separation tower according to a certain proportion; the obtained separation raw material enters a 2-methylpyridine separation tower, rectification is carried out under the rectification condition, and 2-methylpyridine with the increased concentration is obtained on the tower top. The method provided by the invention realizes the purposes of operation under normal pressure and reduction of the temperature of the tower kettle, and reduces the risk of coking of the tower kettle at the same time.

Description

technical field [0001] The present invention relates to a kind of separation method of 2-picoline and aniline, more specifically, is a kind of method that utilizes rectification method to separate 2-picoline and aniline. Background technique [0002] 2-Methyl pyridine, also known as α-methyl pyridine, is a colorless oily liquid with a strong unpleasant pyridine odor. It is used as a raw material for synthesizing medicines, dyes and resins. Livestock repellents, rubber accelerators, dye intermediates, etc. [0003] At present, the traditional method for producing diphenylamine in the industry is to use aniline as a raw material, adopting a liquid-phase kettle type batch reaction to produce, and the catalysts used are HCl, AlCl 3 , NH 4 BF 4 and other halides. The above method has problems such as many by-products, cumbersome process, equipment corrosion, low yield, high product cost, serious pollution, etc., and it is difficult to realize continuous operation and large-sc...

AI Technical Summary

Problems solved by technology

However, in actual production, it is found that the 2-picoline separation tower (also known as the front fraction tower) has the following problems: (1) If the tower adopts vacuum distillation, the advantage is that the temperature at the top of the tower and the temperature of the tower bottom can be reduced at the same time, realizing Energy-saving purpose; the wall of the tower is not easy to coke, and the loss of product yield is small; the disadvantage is that the operation of the tower is easily affected by the fluctuation of vacuum degree, and the device cannot run stably for a long period; at the same time, the operation flexibility of the tower is very small, which increases the difficulty of operation

(2) If the column adopts atmospheric distillation, the advantages are: it is not easy to pan the column, the operation flexibility is large, and the operation difficulty is reduced; the whole production device can run stably for a long time, and the product purity is high (usually the purity of 2-picoline is 99 % above); the disadvantages are: the temperature of the tower top and the tower kettle are high, which is not conducive to energy saving;

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