Method for synthesizing diglycolamine from diglycol by virtue of low-pressure process

Abstract

The invention discloses a method for synthesizing diglycolamine from diglycol by virtue of a low-pressure process. The method comprises the following steps: displacing air in a reactor by use of nitrogen before charging for reaction, and then continuously introducing preheated nitrogen into the reactor so that the temperature of a catalyst in the reactor is increased to the range of 180 to 240 DEG C and the pressure in the reactor is increased to the range of 1.60 to 1.75 MPa; gasifying liquid ammonia, then mixing the gasified ammonia with the hydrogen to obtain a mixed gas, and preheating the mixed gas; mixing diglycol and softened water to obtain a mixed liquid and preheating the mixed liquid; feeding the preheated mixed gas and the preheated mixed liquid into the reactor, performing a gaseous and liquid phase catalyzed ammonolysis reaction in the presence of the catalyst under the conditions of 1.60-1.75MPa and 180-240 DEG C to obtain a crude product; and cooling the obtained crude product and then separating out the gas and the liquid from each other by use of a gas-liquid separator, thereby obtaining the liquid, namely crude diglycolamine. The crude diglycolamine prepared by use of the method for synthesizing the diglycolamine from the diglycol by virtue of the low-pressure process is high in diglycolamine content; the diglycol conversion rate is above 85% and the diglycolamine yield is above 70%.

Description

1. Technical field [0001] The present invention relates to a kind of synthetic method of known compound, specifically a kind of method by diethylene glycol low-pressure synthesis diglycol amine. 2. Background technology [0002] Diethylene glycol amine, also known as 2-(2-aminoethoxy)ethanol, molecular formula C 4 h 11 NO 2 , is a colorless syrupy liquid, is an important solvent and organic raw material, can dissolve with water, can dissolve aromatic hydrocarbons and absorb acid gas (H 2 S and CO 2 ). Diethylene glycol amine is mainly used as an absorbent for acid gas, a surfactant, a wetting agent, and a desulfurizer, and it can also be used as a raw material for polymers. It is widely used in industries such as metals, electronics, and medicine. [0003] Under domestic prior art, also do not have a kind of industrialized production technique method that can use diethylene glycol, liquid ammonia, hydrogen and soft water as raw material synthetic diglycol amine, only ha...

AI Technical Summary

Problems solved by technology

[0011] 1. During the synthesis of diglycolamine, many by-products are generated, which are not easy to remove;

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