Isopropanolamine producing method

Abstract

The invention relates to an isopropanolamine producing method. As the present isopropanolamine producing method uses water as a catalyst, the energy consumption for subsequent dehydration is high and side effects can be easily caused. For this reason, the isopropanolamine producing method of the invention includes tubular reaction, flash evaporation, deamination and rectification, wherein isopropanolamine is used as the catalyst in the tubular reaction; before feeding, a liquid mixture A of anhydrous liquid ammonia and the catalyst is prepared according to the weight ratio of 96-99:1-4; finally, the liquid mixture A and propylene oxide are added according to the feeding speed ratio of 85-340:58. The isopropanolamine producing method realizes low energy consumption and less byproducts in the subsequent dehydration. The invention is applicable to producing the isopropanolamine.

Description

technical field [0001] The present invention relates to a kind of production method for isopropanolamine. Background technique [0002] Modern isopropanolamine production technology uses propylene oxide (PO) and ammonia (NH 3 ) is obtained by reacting with water as a catalyst: [0003] [0004] The one isopropanolamine (hereinafter referred to as one different) that above reaction generates continues to react with propylene oxide to obtain diisopropanolamine (hereinafter referred to as two different): [0005] [0006] The two different that above reaction generates continue to react with propylene oxide to obtain triisopropanolamine (hereinafter referred to as three different): [0007] [0008] If propylene oxide is excessive, then [3] product can continue to react with propylene oxide to generate triisopropanolamine propoxy ether: [0009] [0010] At the same time, water in ammonia can also react with propylene oxide to generate propylene glycol and propyl...

AI Technical Summary

Problems solved by technology

Water enters the reactor in the form of ammonia water, and those with low ammonia concentration (for example <25%) can react under the condition of <1MPa, but the energy consumption of evaporation and dehydration is large, and the presence of a large amount of water will promote (5)(6) ) the occurrence of two side reactions; the high concentration of ammonia (such as 60%-99%) saves energy and requires high pressure, so commonly used tubular reactors, due to the use of water more or less, still have to be dehydrated when obtaining products , the side reactions of (5) and (6) still exist

[0015] 2. All kinds of reactors react while mixing, so that the NH in the partial reaction zone 3 : The molar ratio of PO is much smaller than the macro ratio, which also promotes side reactions

The method uses water as a catalyst in the initial stage of the reaction, and after the system is normal, the mixture of water and one isopropanolamine is used as a catalyst, which does not have the technical prejudice that water must be used as a catalyst for ammonia and propylene oxide. During the process, dehydration treatment must be carried out, which consumes a lot of energy and is prone to side reactions

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