JPH0641019A - Equipment for producing diethyl carbonate and production method using the equipment - Google Patents

Abstract

PURPOSE:To obtain the highly pure diethyl carbonate from ethanol and ethyl chloroformate in a short time by using the first reaction tank and the second reaction tank equipped with a fractionating tower. CONSTITUTION:Ethyl chloroformate (ECF) charged in the first reaction tank 1 is heated to 50-70 deg.C with stirring, dropwisely mixed with ethanol (EtOH) in an EtOH/ECF molar ration of 1.0-2.0, and subsequently heated to 110-130 deg.C to produce diethyl carbonate (DEC). The unreacted EtOH and ECF are distilled out from the top of the fractionating tower 2 with the elevation of temperature, condensed in condensers 4, 5, fed into the second reaction tank 3, heated to an inside temperature of 50-70 deg.C, and subsequently converted into the DEC in the second reaction tank 3. The reaction product in the second reaction tank is partially returned to the fractionating tower in order to improve the separation effect of the fractionating tower.

Description

Detailed Description of the Invention

[0001]

The present invention relates to ethanol (hereinafter referred to as EtO).
H)) and ethyl chloroformate (hereinafter referred to as ECF) to diethyl carbonate (hereinafter referred to as DEC)
The present invention relates to a manufacturing apparatus and a manufacturing method capable of obtaining high-purity DEC in a short time.

[0002]

2. Description of the Related Art DEC is widely used industrially as a raw material for medicine, agriculture and the like and as an organic solvent. In the conventional DEC manufacturing equipment, DEOH was prepared by charging EtOH and ECF in one reaction tank.
C was manufactured. In the reaction of EtOH and ECF, the rate becomes exponentially slower as the reaction proceeds,
An extremely long reaction time was required to obtain the reaction rate of 95% or more.

In order to improve such problems, Et
An example in which the reaction time is shortened by increasing the molar ratio of OH / ECF to react, or after reacting to some extent, by adding EtOH to increase the molar ratio to ECF (Japanese Patent Laid-Open No. Sho 50).
However, it is difficult to obtain high-purity DEC because the unreacted EtOH remains in a large amount, and conversely, if the molar ratio is reduced, the reaction takes a long time.

Further, in the conventional manufacturing method using the DEC manufacturing apparatus, the unreacted E in the DEC reaction solution is produced because the EtOH / ECF molar ratio is increased in order to shorten the reaction time.
A high purity cannot be obtained because the amount of tOH increases, the utility is lost during distillation and purification, the production efficiency decreases, and EtOH easily remains in DEC. Further, in order to solve this problem, if the production is performed with a small molar ratio, a long reaction time is required, and its improvement has been demanded.

[0005]

DISCLOSURE OF THE INVENTION The inventors of the present invention have made extensive studies and studies in order to solve the conventional problems, and as a result,
In producing DEC from EtOH and ECF, it was found that the purpose can be achieved by using the first reaction tank and the second reaction tank with a rectification column (hereinafter referred to as the second reaction tank), and the present invention was achieved. .

That is, according to the present invention, in producing diethyl carbonate from ethanol and ethyl chloroformate, a diethyl carbonate producing apparatus characterized by using a first reaction vessel and a second reaction vessel equipped with a rectification column, and It is a manufacturing method using the apparatus.

The present invention is a DEC manufacturing apparatus equipped with a first reaction tank and a second reaction tank. Etching is performed in the first reaction tank by using this apparatus.
The distillate is introduced into the second reaction tank while being charged and heated to a molar ratio of OH / and ECF of 1.0 or more, and returned to the first reaction tank while performing DEC. By repeating this, The DEC reaction rate can be increased to 99% or more in a short time, and highly pure DEC can be efficiently obtained.

According to the present invention, the second reaction tank is thus provided separately from the first reaction tank in the top line of the rectification column, and the unreacted EtOH distilled from the first reaction tank into the second reaction tank. It is a DEC manufacturing device that can receive the ECF and continue the reaction. The device of the present invention will be described in more detail with reference to FIG.
First, the inner temperature is raised to 50 to 70 ° C. while stirring the first reaction tank (1) charged with ECF, and EtOH is added dropwise. In this case, the EtOH / ECF molar ratio is 1.0 to 2.0,
It is preferably 1.1 to 1.3.

When the molar ratio is increased to 2.0 or more, the reaction becomes faster, but the unreacted EtOH content increases and the distillation time becomes longer, and more DEOH product contains a large amount of EtOH. Further, if the molar ratio is reduced to 1.0 or less, the reaction takes time, which is not preferable.

In the above reaction, after dropping EtOH, 1
The temperature is raised to 10 to 130 ° C. to generate DEC.
As the temperature rises, unreacted EtO from the top of the rectification column (2)
H and ECF are condensed in the distilling condensers (4) and (5) and fed to the second reaction tank (3), and the internal temperature is 50 to 70.
The temperature is raised so that the temperature becomes ℃. This allows EtOH / EC
Since the molar ratio of F is 1 or more, DEC is performed also in this second reaction tank. A part of the second reaction tank (3) is returned to the rectification column in order to improve the separation effect of the rectification column. This is repeated to carry out the DEC reaction.

By providing the first reaction tank (1) and the second reaction tank (3) as described above, the reaction time required for the DEC reaction rate to be 99% or more is 10 hours or less,
Moreover, since the amount of unreacted EtOH is small during distillation, highly pure DEC can be efficiently produced.

Further, the DEC reaction solution thus obtained is subjected to atmospheric distillation in the first reaction tank, the first fraction is received in the second reaction tank, and the distilled DEC is transferred to the product tank (6). The first fraction is returned to the first reaction tank for effective use during the next production.

[0013]

EXAMPLES The present invention will now be described in more detail by way of examples. In addition,% in an Example shows weight%.

Example 1 The first reaction tank was charged so that the molar ratio EtOH / ECF was 1.1. First, ECF was charged and the internal temperature was raised to 50 to 70 ° C. with stirring. Next, after adding EtOH dropwise, the internal temperature is further raised to 110 to 130 ° C., and while producing DEC, it is heated in the rectification column and passed through two condensers, and the condensate is fed to the second reaction tank. . Next, the internal temperature is raised to 50 to 70 ° C. to accelerate the generation of DEC. When the appropriate amount of each of the condensate and DEC product in the second reaction tank is returned to the rectification column and repeated for 8 to 10 hours, D
The EC reaction rate becomes 99% or more, and the reaction is completed. This D
DEC obtained by atmospheric distillation of EC reaction liquid
The composition of DEC is 99.5%, EtOH is 0.4%,
The ECF was 0.1% or less.

Example 2 The first reaction tank is charged so that the molar ratio EtOH / ECF is 1.3. First, the ECF is charged and the internal temperature is raised to 50 to 70 ° C. with stirring. Next, after adding EtOH dropwise, the internal temperature is further raised to 110 to 130 ° C., and while producing DEC, it is heated in the rectification column and fed through the two condensers to the condensate to the second reaction tank. Next, the internal temperature is raised to 50 to 70 ° C. to accelerate the generation of DEC. When the appropriate amount of each of the condensate and DEC production liquid in the second reaction tank is returned to the rectification column and repeated for 9 hours, the DEC reaction rate becomes 99% or more and the reaction is completed. The composition of DEC obtained by distilling this DEC reaction solution under atmospheric pressure is as follows: DEC 99.2%, EtOH 0.7%, ECF
It was 0.1% or less.

Comparative Example 1 A reaction vessel equipped with a condenser was charged so that the molar ratio of EtOH / ECF was 1.3. First, the internal temperature was raised to 50 to 70 ° C. while stirring the ECF and stirring to increase the EtOH. Is dripped. After the dropwise addition of EtOH, the reaction temperature of the reaction tank is gradually raised to carry out the DEC reaction at 60 to 80 ° C. When this reaction was continued and the DEC reaction rate became 99% or more, the reaction was terminated, and the reaction time required for this reaction was 40 hours or more. The composition of DEC obtained by distilling this reaction solution under atmospheric pressure was as follows: DEC 89.4%, EtOH 10.5%, EC
F was 0.1% or less.

Comparative Example 2 A reaction vessel equipped with a condenser was charged so that the molar ratio of EtOH / ECF was 2.0. First, the internal temperature was raised to 50 to 70 ° C. while stirring the ECF and stirring to increase the EtOH. Is dripped. After the dropwise addition of EtOH, the reaction temperature of the reaction tank is gradually raised to carry out the DEC reaction at 60 to 80 ° C. When this reaction was continued and the DEC reaction rate became 99% or more, the reaction was terminated, and the reaction time required for this reaction was 10 to 12 hours. The composition of DEC obtained by distilling this reaction solution under atmospheric pressure was as follows: DEC 70.5%, EtOH 29.4%, E
The CF was 0.1% or less.

[0018]

EFFECT OF THE INVENTION High-purity DE, which was difficult to obtain by conventional techniques
A DEC manufacturing apparatus for obtaining C in a short time was established. This is extremely advantageous industrially, and the first fraction obtained by distillation of the DEC reaction solution is received in the second reaction tank and can be effectively used for the next reaction. Therefore, according to the present invention, high-purity DEC can be produced economically and efficiently.

[Brief description of drawings]

FIG. 1 is an overall view of a DEC manufacturing apparatus according to the present invention.

[Explanation of symbols]

 1 1st reaction tank 2 Fractionation tower 3 2nd reaction tank with rectification 4 1st condenser 5 2nd condenser 6 Product tank 7 Liquid feed pump 8 Product filling 9 Detoxification equipment

Claims (2)

[Claims] 1. An apparatus for producing diethyl carbonate, characterized in that a first reaction vessel and a second reaction vessel equipped with a rectification column are used for producing diethyl carbonate from ethanol and ethyl chloroformate. 2. Using the apparatus according to claim 1, the molar ratio of ethanol and ethyl chloroformate is 1.0.
A method for producing a high-purity diethyl carbonate in a short time by reacting at ~ 2.0.