Preparation method of 1,2-propane diamine

Abstract

The invention discloses a preparation method of 1,2-propane diamine, which comprises the following steps of: adding 1,2-dichloropropane, water, liquid ammonia and a catalyst in a high-pressure reactor, raising the temperature to 160-180 DEG C and the pressure to 8-12MPa, and keeping the conditions for reacting for 4-5h; and sampling for carrying out GC (Gas Chromatograph) detection, completely reacting the 1,2-dichloropropane, cooling a reaction system to 20-25 DEG C, discharging excessive ammonia gas, preparing a mixture using the 1,2-propane diamine as a main component, and rectifying the 1,2-propane diamine to obtain a finished product. According to the preparation method, the process steps are greatly simplified, pollution emission does not exist basically, and the cost is lowered. Excessive ammonia after the reaction is ended can be recycled, and the preparation process can be completed in one high-pressure reactor, so that the investment and production efficiency of equipment are greatly reduced. According to the invention, complete reaction can be completed by adopting one catalyst, and low distillates obtained after rectification can be used as raw materials for recycling, so that the selectivity of the 1,2-propane diamine is greatly increased.

Description

technical field [0001] The invention belongs to the field of organic synthesis, and in particular relates to a preparation method of 1,2-propanediamine. Background technique [0002] 1,2-Propylenediamine (DAP) is an important fine chemical intermediate, widely used in the fields of organic synthesis, medicine, dyestuff, pesticide, chemical additives, rubber plastic additives and epoxy resin curing agent, etc. . Compared with ethylenediamine, DAP has good oil solubility and can be used as an oil passivator. After splitting DAP, dextro-DAP can be obtained, and then propylimine (dex-rotatory dexrazoxane) can be synthesized. In the production of spandex elastic fibers, DAP can be used as a chain extender. DAP can also be used to prepare anionic surfactants. [0003] The market demand for this product is increasing year by year. It is mainly imported by foreign companies such as BASF, and the price is expensive. At present, the market demand for 1,2-propanediamine in the Ch...

AI Technical Summary

Problems solved by technology

Mainly imported by foreign companies such as BASF, the price is expensive

At present, the market demand for 1,2-propanediamine in the Chinese market is 1000-2000 tons per year, but there are few manufacturers in China. The technology is backward and the product quality is not high. At present, the traditional art is to use 1,2-diamine Chloropropane ammonolysis production, the method yield is low, and organic chlorine compounds seriously pollute the environment

It is also reported that acrylonitrile method is useful abroad for synthesis, but this method has high pressure and expensive raw material cost