Method for preparing monoisopropanolamine by virtue of reactive rectification

Abstract

The invention provides a method for preparing monoisopropanolamine by virtue of reactive rectification. The method comprises the following steps: feeding liquid ammonia from the lower part of a reactive rectification tower by use of a pressure reducing valve, meanwhile, feeding propylene epoxide from the second tower plate at the upper part of the tower at 25 DEG C, and feeding catalyst water from the top of the tower at a temperature ranging from 15 to 40 DEG C, wherein the feeding molar ratio of the fed ammonia to the propylene epoxide is (0.8-2.0): 1, the feed quantity of the water is 10-50% of the mass percentage of the total feed quantity, and the total feed quantity is the mass sum of the water, liquid ammonia and propylene epoxide; the reactive rectification tower comprises 25-45 tower plates; the temperature at the top of the tower is controlled within the range of 31-50 DEG C, the temperature of the tower kettle is within the range of 165-310 DEG C, and the tower is under the pressure of 0.8MPa to 1.5MPa; the liquid ammonia feeding position is at the tower kettle of the reactive rectification tower or the first or second tower plate above the tower kettle. Compared with the traditional process, the method has the advantages that the content of monoisopropanolamine is increased by nearly 100%, and the content of triisopropanolamine is reduced by about 95% in comparison with the traditional process.

Description

technical field [0001] The invention belongs to the field of chemical reaction and separation, and specifically relates to a method for preparing monoisopropanolamine through reactive distillation. Background technique [0002] One isopropanolamine is 1-amino-2-propanol (chemical formula: CH 3 CH(OH)CH 2 NH 2 ), also known as monoisopropanolamine. Monoisopropanolamine has a wide range of uses: it can be used in household chemicals such as detergents, liquid detergents, and shampoos; it can be used in fabrics, wool spinning, and leather auxiliaries; it can be used in detergents for metal electronic liquid crystals and semiconductors; it can be used Used in the synthesis of pharmaceuticals, pesticides and flavors and fragrances intermediates. [0003] The reaction of propylene oxide and ammonia is strongly exothermic. When there is absolutely no water, it is difficult for propylene oxide to react with ammonia, and the addition of water can initiate a catalytic reaction. ...

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to aim at the high ratio of molar ratio of ammonia ring to feed that exists in the traditional monoisopropanolamine production process, the huge energy consumption produced in the deamination and dehydration process, various equipment and high proportion of triisopropanolamine in the product Insufficient, provide a kind of reactive distillation to prepare the production technique of monoisopropanolamine, this technique will react and separate and synthesize one step, while reducing the energy consumption in the traditional technique, dwindled the ammonia ring molar ratio (0.8-2.0), Improve product selectivity, the reaction product is monoisopropanolamine, a small amount of diisopropanolamine, and does not generate triisopropanolamine

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