Method for preparing N-methylmorpholine through catalyst

Abstract

The invention discloses a method for preparing N-methylmorpholine through a catalyst. The method comprises the following steps that 1, a rare-earth-based solid catalyst is loaded in a tubular reactor; 2, a liquid raw material N-methyldiethanolamine is put into a raw material tank, rapid sampling is conducted by means of a sampling pump, and a feed solution is subjected to an intramolecular dehydration reaction through the rare-earth-based solid catalyst in the tubular reactor, wherein the liquid hourly space velocity of the feed solution ranges from 0.1 h<-1> to 0.5 h<-1>, and the temperature of the reactor ranges from 200 DEG C to 300 DEG C; 3, a reaction solution obtained in the second step is condensed and collected through a condenser, caustic soda flakes are added to make the reaction solution layered, supernatant liquid is taken for normal pressure rectification, fractions of 115 DEG C-116 DEG C are collected, and a target product N-methylmorpholine is obtained. The method is simple and feasible, the conversion rate is high, the catalyst can be used repeatedly, and the catalytic efficiency is not obviously lowered after the catalyst is used repeatedly 60 times.

Description

technical field

[0001] The invention belongs to the field of chemical industry and relates to chemical intermediates, in particular to a method for catalytically preparing N-methylmorpholine. Background technique

[0002] N-Methylmorpholine is a heterocyclic tertiary amine. The pure product is a colorless liquid with an ammonia smell. It is mainly used as a foaming catalyst, extraction agent, solvent, etc. for the synthesis of polyurethane plastics. It is also a synthetic medicine, pesticide, surface Important intermediates of active agents, etc.

[0003] The existing methods for synthesizing N-methylmorpholine are relatively cumbersome, or the conversion rate is low. Contents of the invention

[0004] The object of the present invention is to provide a kind of method that catalyzes the preparation of N-methylmorpholine.

[0005] Above-mentioned purpose of the present invention is achieved by following technical scheme:

[0006] A method for catalytically preparing N-me...

Examples

Embodiment 1

[0019] Embodiment 1: the method for catalytically preparing N-methylmorpholine

[0020] Including the preparation steps as described below:

[0021] Step S1, packing the rare earth-based solid catalyst into the tubular reactor;

[0022] In step S2, the liquid raw material N-methyldiethanolamine is placed in the raw material tank, and the sample is fed at a constant speed by a sampling pump. The raw material liquid passes through the rare earth-based solid catalyst in the tubular reactor for intramolecular dehydration reaction, and the liquid volume of the raw material liquid is Airspeed is 0.3h- 1 , the reactor temperature is 250°C;

[0023] Step S3, condensing and collecting the reaction solution obtained in step S2 through a condenser, adding caustic soda to separate the reaction solution, taking the upper liquid for atmospheric distillation, collecting fractions at 115-116°C, and obtaining the target product N-methylmorpholine; liter of reaction solution was added caust...

Embodiment 2

[0026] Embodiment 2: the method for catalytically preparing N-methylmorpholine

[0027] Including the preparation steps as described below:

[0028] Step S1, packing the rare earth-based solid catalyst into the tubular reactor;

[0029] In step S2, the liquid raw material N-methyldiethanolamine is placed in the raw material tank, and the sample is fed at a constant speed by a sampling pump. The raw material liquid passes through the rare earth-based solid catalyst in the tubular reactor for intramolecular dehydration reaction, and the liquid volume of the raw material liquid is The air speed is 0.1h -1 , the reactor temperature is 200°C;

[0030] Step S3, condensing and collecting the reaction solution obtained in step S2 through a condenser, adding caustic soda to separate the reaction solution, taking the upper liquid for atmospheric distillation, collecting fractions at 115-116°C, and obtaining the target product N-methylmorpholine; Add 2 g of caustic soda to the liter...

Embodiment 3

[0033] Embodiment 3: the method for catalytically preparing N-methylmorpholine

[0034] Including the preparation steps as described below:

[0035] Step S1, packing the rare earth-based solid catalyst into the tubular reactor;

[0036] In step S2, the liquid raw material N-methyldiethanolamine is placed in the raw material tank, and the sample is fed at a constant speed by a sampling pump. The raw material liquid passes through the rare earth-based solid catalyst in the tubular reactor for intramolecular dehydration reaction, and the liquid volume of the raw material liquid is Airspeed is 0.5h -1 , the reactor temperature is 300°C;

[0037] Step S3, condensing and collecting the reaction solution obtained in step S2 through a condenser, adding caustic soda to separate the reaction solution, taking the upper liquid for atmospheric distillation, collecting fractions at 115-116°C, and obtaining the target product N-methylmorpholine; Add caustic soda 4g to liter reaction sol...

technical field

[0001] The invention belongs to the field of chemical industry and relates to chemical intermediates, in particular to a method for catalytically preparing N-methylmorpholine. Background technique

[0002] N-Methylmorpholine is a heterocyclic tertiary amine. The pure product is a colorless liquid with an ammonia smell. It is mainly used as a foaming catalyst, extraction agent, solvent, etc. for the synthesis of polyurethane plastics. It is also a synthetic medicine, pesticide, surface Important intermediates of active agents, etc.

[0003] The existing methods for synthesizing N-methylmorpholine are relatively cumbersome, or the conversion rate is low. Contents of the invention

[0004] The object of the present invention is to provide a kind of method that catalyzes the preparation of N-methylmorpholine.

[0005] Above-mentioned purpose of the present invention is achieved by following technical scheme:

[0006] A method for catalytically preparing N-me...

Examples

Embodiment 1

[0019] Embodiment 1: the method for catalytically preparing N-methylmorpholine

[0020] Including the preparation steps as described below:

[0021] Step S1, packing the rare earth-based solid catalyst into the tubular reactor;

[0022] In step S2, the liquid raw material N-methyldiethanolamine is placed in the raw material tank, and the sample is fed at a constant speed by a sampling pump. The raw material liquid passes through the rare earth-based solid catalyst in the tubular reactor for intramolecular dehydration reaction, and the liquid volume of the raw material liquid is Airspeed is 0.3h- 1 , the reactor temperature is 250°C;

[0023] Step S3, condensing and collecting the reaction solution obtained in step S2 through a condenser, adding caustic soda to separate the reaction solution, taking the upper liquid for atmospheric distillation, collecting fractions at 115-116°C, and obtaining the target product N-methylmorpholine; liter of reaction solution was added caust...

Embodiment 2

[0026] Embodiment 2: the method for catalytically preparing N-methylmorpholine

[0027] Including the preparation steps as described below:

[0028] Step S1, packing the rare earth-based solid catalyst into the tubular reactor;

[0029] In step S2, the liquid raw material N-methyldiethanolamine is placed in the raw material tank, and the sample is fed at a constant speed by a sampling pump. The raw material liquid passes through the rare earth-based solid catalyst in the tubular reactor for intramolecular dehydration reaction, and the liquid volume of the raw material liquid is The air speed is 0.1h -1 , the reactor temperature is 200°C;

[0030] Step S3, condensing and collecting the reaction solution obtained in step S2 through a condenser, adding caustic soda to separate the reaction solution, taking the upper liquid for atmospheric distillation, collecting fractions at 115-116°C, and obtaining the target product N-methylmorpholine; Add 2 g of caustic soda to the liter...

Embodiment 3

[0033] Embodiment 3: the method for catalytically preparing N-methylmorpholine

[0034] Including the preparation steps as described below:

[0035] Step S1, packing the rare earth-based solid catalyst into the tubular reactor;

[0036] In step S2, the liquid raw material N-methyldiethanolamine is placed in the raw material tank, and the sample is fed at a constant speed by a sampling pump. The raw material liquid passes through the rare earth-based solid catalyst in the tubular reactor for intramolecular dehydration reaction, and the liquid volume of the raw material liquid is Airspeed is 0.5h -1 , the reactor temperature is 300°C;

[0037] Step S3, condensing and collecting the reaction solution obtained in step S2 through a condenser, adding caustic soda to separate the reaction solution, taking the upper liquid for atmospheric distillation, collecting fractions at 115-116°C, and obtaining the target product N-methylmorpholine; Add caustic soda 4g to liter reaction sol...