阅读说明：本技术 一种选择性生产三乙胺的方法 (Method for selectively producing triethylamine ) 是由 王恒文 许国峰 于 2020-06-29 设计创作，主要内容包括：本发明属于化工生产领域,尤其涉及一种选择性生产三乙胺的方法。包括以下步骤：(1)质量比为4.5-7.8:1的乙醇、液氨混合液经预热、汽化、换热后进入反应釜,在临氢状态下进行气相催化反应,多次分馏分别得到一乙胺、二乙胺、三乙胺；(2)将步骤(1)部分二乙胺与乙醇,按照二乙胺与乙醇摩尔比1：1混合加热至150℃,反应,得到三乙胺。本发明以乙醇及液氨为原料进行加工生产,然后用二乙胺与乙醇反应,得到二乙胺与三乙胺的比值可以通过后续反应操作,弹性大,市场适应性强。(The invention belongs to the field of chemical production, and particularly relates to a method for selectively producing triethylamine. The method comprises the following steps: (1) preheating, vaporizing and heat-exchanging the mixed solution of ethanol and liquid ammonia with the mass ratio of 4.5-7.8:1, then feeding the mixed solution into a reaction kettle, carrying out gas-phase catalytic reaction in the presence of hydrogen, and carrying out fractional distillation for multiple times to respectively obtain monoethylamine, diethylamine and triethylamine; (2) mixing part of diethylamine and ethanol obtained in the step (1) according to a molar ratio of the diethylamine to the ethanol of 1: 1, mixing and heating to 150 ℃, and reacting to obtain triethylamine. According to the invention, ethanol and liquid ammonia are used as raw materials for processing production, and then diethylamine is used for reacting with ethanol, so that the ratio of the diethylamine to triethylamine can be obtained through subsequent reaction operation, and the method has the advantages of high elasticity and strong market adaptability.)

1. A method for selectively producing triethylamine is characterized by comprising the following steps:

(1) preheating, vaporizing and heat-exchanging the mixed solution of ethanol and liquid ammonia with the mass ratio of 4.5-7.8:1, then feeding the mixed solution into a reaction kettle, carrying out gas-phase catalytic reaction in the presence of hydrogen, and carrying out fractional distillation for multiple times to respectively obtain monoethylamine, diethylamine and triethylamine;

(2) mixing part of diethylamine and ethanol obtained in the step (1) according to a molar ratio of the diethylamine to the ethanol of 1: 1, mixing and heating to 150 ℃, and reacting to obtain triethylamine.

2. The method according to claim 1, wherein the step (2) is to return part of the diethylamine in the step (1) to the ethanol-liquid ammonia mixed solution in the step (1).

3. The method according to claim 1, wherein a steam recovery device is added in the step (1), desalted water is used for absorbing the exothermicity of the whole reaction, pressure is generated in a steam drum, and then the steam is sent to a heating device.

4. The method of claim 1, wherein the step (2) reaction is carried out in a tubular reactor.

5. The method as claimed in claim 1 or 3, wherein the reaction vessel of the step (1) is jacketed and filled with a noble metal cobalt-based catalyst.

6. The method of claim 1, wherein the catalyst for the reaction in step (2) is a noble metal cobalt catalyst.

7. Triethylamine prepared by the process of claim 1.

Technical Field

The invention belongs to the field of chemical production, and particularly relates to a method for selectively producing triethylamine.

Background

The ethylamine is widely used for dye synthesis and used as an extracting agent, an emulsifying agent, a medical raw material, a reagent and the like, and the demand for high-quality ethylamine in the market is increased rapidly along with the rapid development of the industries such as Chinese medicines, pesticides, dyes, auxiliaries, rubber and the like in recent years, so that the ethylamine has a better market prospect in China, and Shandong is the main consumption province of domestic ethylamine, so that the ethylamine has a larger market potential.

At present, there are two domestic methods for producing ethylamine, namely, a normal pressure method and a pressurization method. The normal pressure method is industrialized in sixties, and the pressure method is a production device in the eighties. Both methods have relatively mature process technologies, and a lot of experience is accumulated in production practice. The normal pressure method has simple process flow, low requirement on equipment and suitability for small-scale production, while the pressure method has complex process flow, higher requirement on equipment and control level, suitability for large-scale production and large investment of the device at one time. The normal pressure method and the pressurization method have small yield, low ethanol conversion rate, one more hydrogen circulation in the raw materials, and the balance pressure of a hydrogen cabinet is released, so that the useful materials escape, and the production cost is higher.

Meanwhile, monoethylamine is mainly used for fuel synthesis, an extracting agent, an emulsifying agent, a medical raw material, a detergent, a lubricant, a rubber accelerator, an antioxidant and the like. The diethylamine can be used as synthesis intermediate, epoxy resin curing agent, and other medicines such as procaine, chloroquine, nicotemide, coramine and sulfonamides. Triethylamine can be used as catalyst of polycarbonate phosgene method and polymerization inhibitor of tetrachloroethylene, food antiseptic, emulsifier, synthetic fuel, high-energy fuel, etc. The traditional process flow is single, and the temperature is used for controlling ethanol and liquid ammonia to produce the triethylamine. Resulting in poor product selectivity and inability to adjust production configurations based on market demand. Meanwhile, a large amount of diethylamine in the system is circulated, and the energy consumption is increased. In addition, the demand of triethylamine is high, so that selective production of triethylamine is also a problem to be solved.

Disclosure of Invention

The method for selectively producing triethylamine is characterized in that ethanol and liquid ammonia are used as raw materials for processing production, then diethylamine and ethanol are used for reaction, the ratio of the obtained diethylamine to the triethylamine can be subjected to subsequent reaction operation, and the method is high in elasticity and strong in market adaptability.

The technical scheme of the invention is as follows:

a method for selectively producing triethylamine, comprising the steps of:

(1) preheating, vaporizing and heat-exchanging the mixed solution of ethanol and liquid ammonia with the mass ratio of 4.5-7.8:1, then feeding the mixed solution into a reaction kettle, carrying out gas-phase catalytic reaction in the presence of hydrogen, and carrying out fractional distillation for multiple times to respectively obtain monoethylamine, diethylamine and triethylamine;

(2) mixing part of diethylamine and ethanol obtained in the step (1) according to a molar ratio of the diethylamine to the ethanol of 1: 1, mixing and heating to 150 ℃, and reacting to obtain triethylamine.

Preferably, the step (2) is to return part of the diethylamine in the step (1) to the mixed solution of ethanol and liquid ammonia in the step (1).

Preferably, a steam recovery device is added in the step (1), desalted water is used for absorbing the heat release of the whole reaction, pressure is generated in a steam drum, and then the steam is sent to a heating device.

Preferably, the step (2) reaction adopts a tubular reactor.

Preferably, the reaction kettle of the step (1) is provided with a jacket and is filled with a noble metal cobalt catalyst.

Preferably, the catalyst for the reaction in step (2) is a noble metal cobalt catalyst.

Triethylamine prepared by the method.

The project controls the proportion of raw materials ethanol and liquid ammonia, carries out gas phase catalytic reaction in a hydrogen state, fractionates for multiple times to respectively obtain monoethylamine, diethylamine and triethylamine, and then produces triethylamine by reacting part of diethylamine with ethanol.

The invention has the advantages of

(1) High market adaptability

According to the invention, ethanol and liquid ammonia are used as raw materials for processing production, and then diethylamine is used for reacting with ethanol, so that the ratio of diethylamine to triethylamine can be obtained through subsequent reaction operation, the elasticity is large, the market adaptability is strong, and the ratio range of triethylamine is 25-85%. The production amount of diethylamine is about 45%, and the actual demand is about 20%. In order to reduce the yield of the diethylamine, the excess 25 percent of the diethylamine is recycled to the reactor to produce the triethylamine, thereby increasing the load of the system. Therefore, the invention adopts the additional reactor, simultaneously recycles the heat energy released by the reaction and reduces the energy consumption.

(2) Low energy consumption

By adopting the method, a large amount of circulating diethylamine in the original system is reduced, the energy consumption is reduced, and the productivity is increased to 145 tons/day from 100 tons/day.

Drawings

FIG. 1 is a process diagram for producing triethylamine in example 1.

FIG. 2 is a process diagram for producing triethylamine in examples 2 and 3.

FIG. 3 is a process diagram for producing triethylamine in example 4.

Detailed Description

The invention is further illustrated by the following specific examples in combination with the accompanying drawings.

A method for selectively producing triethylamine, comprising the steps of:

(1) ethanol and liquid ammonia in a mass ratio of 4.5:1, namely the feeding amount of ethanol: 4275kg/h and 950kg/h of liquid ammonia feeding amount; the mixed liquid is pressurized to 2.8MPa by a circulating pump, conveyed to an alcohol preheater with the preheating temperature of 80 ℃ and enters a vaporizer. The mixed material is heated to 130 ℃ in a vaporizer, enters a heat exchanger, exchanges heat with the reacted material to 140 ℃, and enters a fixed bed reactor. Four layers of metal cobalt catalysts are filled in the fixed bed reactor, and the mixed materials are subjected to gas phase catalytic reaction under the hydrogen condition of 1.5MPa and 140 ℃; and (3) performing heat exchange condensation on the obtained mixed material after the reaction to 60 ℃, wherein the material proportion is liquid ammonia: 3%, ethanol: 5%, monoethylamine: 15%, diethylamine: 45%, triethylamine: 15%, water: 17 percent; the method comprises the steps of sequentially extracting unreacted liquid ammonia with the concentration of 3 percent in an ammonia tower, extracting 15 percent monoethylamine in a monoethylamine tower, extracting 45 percent diethylamine in a diethylamine tower, extracting unreacted ethanol with the concentration of 5 percent in an alcohol tower, and extracting 15 percent triethylamine in a triethylamine tower. About 15000kg/d of monoethylamine, about 45000kg/d of diethylamine and about 15000kg/d of triethylamine are separated by multi-stage distillation.