Method and device for separating and purifying 2, 4-diaminotoluene in toluenediamine mixture

Abstract

The invention relates to the technical field of chemical purifying and separating, and particularly relates to a method and device for separating and purifying 2, 4-diaminotoluene in toluenediamine mixture. The method and the device are simple and high in efficiency. The device comprises an ingredient dissolving and cooling and devitrifying device, a separating drying device, a rectifying separating device, a devitrifying cooling device, a receiving bucket and a DCS control device, wherein a feeding pipe is arranged on the ingredient dissolving and cooling and devitrifying device; the output end of the separating drying device is communicated with the receiving bucket through a seventh communication pipe; ingredient dissolving and cooling and devitrifying device, the separating drying device, the rectifying separating device, the devitrifying cooling device and the receiving bucket are electrically connected to the DCS control device; control pumps, heaters and coolers are arranged ona first communication pipe, a second communication pipe, a third communication pipe, a fourth communication pipe, a fifth communication pipe, a sixth communication pipe and a seventh communication pipe.

Description

technical field [0001] The invention relates to the technical field of chemical separation and purification, in particular to a method and a device for separating and purifying 2,4-diaminotoluene in a toluenediamine mixture. Background technique [0002] As we all know, 2,4-diaminotoluene is an important dye intermediate and an important raw material for the production of toluene diisocyanate (TDI). The method of industrially synthesizing TDA is usually to first nitrate toluene to obtain mixed dinitrotoluene, and then obtain meta-position mixed dinitrotoluene after rectification and separation to remove ortho-position dinitrotoluene, and then reduce to obtain mixed TDA, 2,4- There are mainly two ratios (mass ratio) of TDA and 2,6-TDA content, 80:20 or 65:35. Because the dyes synthesized from pure 2,4-TDA have better color and the performance of polyurethane is better, so the economical and efficient production process of purifying 2,4-TDA has broad industrial prospects. ...

AI Technical Summary

Problems solved by technology

Domestic manufacturers of 2,4-diaminotoluene mostly use 2,4-dinitrotoluene to reduce with iron powder under acidic conditions to produce 2,4-diaminotoluene. This process will produce a large amount of acidic wastewater, Waste residue, causing serious environmental pollution, this method is gradually being eliminated

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