阅读说明：本技术 一种碳酸二甲酯的制备方法 (Preparation method of dimethyl carbonate ) 是由 肖睿 张文瑄 张浩然 肖熙美 肖小勇 于 2021-07-14 设计创作，主要内容包括：本申请涉及碳酸二甲酯的领域,更具体地说,它涉及一种碳酸二甲酯的制备方法,包括如下步骤：将甲醇以50～60℃的温度加热5～10min；向加热后的甲醇中加入二氯代碳酸乙烯酯、碳酸乙烯酯及催化剂,并进行保温反应；完成(2)中的保温反应后,即得碳酸二甲酯。本申请的制备方法中的原料中不含重金属元素,从而使最终生成的碳酸二甲酯中的重金属含量极少,使用安全；采用二氯代碳酸乙烯酯作为原料之一,二氯代碳酸乙烯酯是制备氯代碳酸乙烯酯的副产物,其具有一定的毒性,且难以处理,通过利用二氯代碳酸乙烯酯制备碳酸二甲酯,起到废物利用,且减少污染的环保效益。(The application relates to the field of dimethyl carbonate, in particular to a preparation method of dimethyl carbonate, which comprises the following steps: heating methanol at 50-60 ℃ for 5-10 min; adding dichloroethylene carbonate, ethylene carbonate and a catalyst into the heated methanol, and carrying out heat preservation reaction; and (3) after the heat preservation reaction in the step (2) is finished, obtaining the dimethyl carbonate. The raw materials in the preparation method do not contain heavy metal elements, so that the finally generated dimethyl carbonate has extremely low heavy metal content and is safe to use; the dichloroethylene carbonate is adopted as one of raw materials, the dichloroethylene carbonate is a byproduct for preparing the chloroethylene carbonate, has certain toxicity and is difficult to treat, and the dimethyl carbonate is prepared by utilizing the dichloroethylene carbonate, so that the waste utilization is realized, and the environmental protection benefit of pollution reduction is realized.)

1. The preparation method of the dimethyl carbonate is characterized by comprising the following steps:

(1) heating methanol at 50-60 ℃ for 5-10 min;

(2) adding dichloroethylene carbonate, ethylene carbonate and a catalyst into the methanol heated in the step (1), and carrying out heat preservation reaction;

(3) and (3) after the heat preservation reaction in the step (2) is finished, obtaining the dimethyl carbonate.

2. The method according to claim 1, wherein the molar ratio of methanol to ethylene dichlorocarbonate in the step (2) is 2 to 10.

3. The method according to claim 2, wherein the mass ratio of ethylene dichlorocarbonate to the catalyst in the step (2) is 0.05 to 1.

4. The method according to claim 2, wherein the mass ratio of ethylene dichlorocarbonate to ethylene carbonate in the step (2) is 1 to 4.

5. The method for preparing dimethyl carbonate according to claim 1, wherein the reaction temperature in the step (2) is 50 to 60 ℃.

6. The method for preparing dimethyl carbonate according to claim 1, wherein the reaction time in the step (2) is 4-8 h.

7. The method for preparing dimethyl carbonate according to claim 1, wherein the step (2) further comprises absorbing the tail gas by using diatom ooze.

8. The method for producing dimethyl carbonate according to any one of claims 1 to 7, wherein the catalyst is a quaternary phosphonium salt catalyst.

Technical Field

The application relates to the field of dimethyl carbonate, in particular to a preparation method of dimethyl carbonate.

Background

Dimethyl carbonate has a wide range of applications, for example, in the fields of medicines, agricultural chemicals, synthetic materials, dyes, lubricants, etc., and can also be used as a solvent, a gasoline additive, etc.

Dimethyl carbonate prepared by the prior art often contains more heavy metal residues, and the preparation process is not environment-friendly.

Disclosure of Invention

In order to solve the problems that the existing dimethyl carbonate contains more residual heavy metals and the preparation method is not environment-friendly, the preparation method of the dimethyl carbonate is provided. The method has the advantages of waste utilization, pollution reduction, environmental protection and almost no heavy metal.

The application provides a preparation method of dimethyl carbonate, which adopts the following technical scheme:

a preparation method of dimethyl carbonate comprises the following steps:

(1) heating methanol at 50-60 ℃ for 5-10 min;

(2) adding dichloroethylene carbonate, ethylene carbonate and a catalyst into the methanol heated in the step (1), and carrying out heat preservation reaction;

(3) and (3) after the heat preservation reaction in the step (2) is finished, obtaining the dimethyl carbonate.

Further, the molar ratio of the methanol to the ethylene dichlorocarbonate in the step (2) is 2-10.

Further, the mass ratio of the dichloroethylene carbonate to the catalyst in the step (2) is 0.05-1.

Further, in the step (2), the mass ratio of the dichloroethylene carbonate to the ethylene carbonate is 1 to 4.

Further, the reaction temperature in the step (2) is 50-60 ℃.

Further, the reaction time in the step (2) is 4-8 h.

Further, the step (2) further comprises absorbing the tail gas by using diatom ooze.

Further, the catalyst is a quaternary phosphonium salt catalyst.

In summary, the present application has the following beneficial effects:

1. the raw materials for preparation do not contain heavy metal elements, so that the finally generated dimethyl carbonate has extremely low heavy metal content and is safe to use;

2. dichloroethylene carbonate is adopted as one of raw materials, the dichloroethylene carbonate is a byproduct for preparing the chloroethylene carbonate, has certain toxicity and is difficult to treat, and dimethyl carbonate is prepared by utilizing the dichloroethylene carbonate, so that the waste utilization is realized, and the environmental protection benefit of pollution reduction is realized;

3. and the diatom ooze is used for absorbing tail gas, so that the discharge of chlorine-containing substances generated in the preparation process can be reduced, and the environmental protection benefit is further increased.

Detailed Description

The present application will be described in further detail with reference to examples.

Examples

Example 1

A preparation method of dimethyl carbonate comprises the following steps:

(1) heating methanol at 50 deg.C for 10 min;

(2) adding dichloroethylene carbonate, ethylene carbonate and a quaternary phosphonium salt catalyst into the heated methanol in the step (1), carrying out heat preservation reaction for 8 hours at the temperature of 50 ℃, and absorbing tail gas by utilizing diatom ooze during the reaction;

(3) and (3) after the heat preservation reaction in the step (2) is finished, obtaining the dimethyl carbonate.

In the step (2), the molar ratio of the methanol to the ethylene dichlorocarbonate is 2;

in the step (2), the mass ratio of the ethylene dichlorocarbonate to the quaternary phosphonium salt catalyst is 0.05;

in the step (2), the mass ratio of ethylene dichlorocarbonate to ethylene carbonate is 1.

Example 2

A preparation method of dimethyl carbonate comprises the following steps:

(1) heating methanol at 55 deg.C for 8 min;

(2) adding dichloroethylene carbonate, ethylene carbonate and a quaternary phosphonium salt catalyst into the heated methanol obtained in the step (1), carrying out heat preservation reaction for 5 hours at the temperature of 55 ℃, and absorbing tail gas by utilizing diatom ooze during the reaction;

(3) and (3) after the heat preservation reaction in the step (2) is finished, obtaining the dimethyl carbonate.

In the step (2), the molar ratio of the methanol to the ethylene dichlorocarbonate is 6;

in the step (2), the mass ratio of the ethylene dichlorocarbonate to the quaternary phosphonium salt catalyst is 0.15;

in the step (2), the mass ratio of ethylene dichlorocarbonate to ethylene carbonate is 2.

Example 3

A preparation method of dimethyl carbonate comprises the following steps:

(1) heating methanol at 60 deg.C for 5 min;

(2) adding dichloroethylene carbonate, ethylene carbonate and a quaternary phosphonium salt catalyst into the heated methanol obtained in the step (1), carrying out heat preservation reaction for 4 hours at the temperature of 60 ℃, and absorbing tail gas by utilizing diatom ooze during the reaction;

(3) and (3) after the heat preservation reaction in the step (2) is finished, obtaining the dimethyl carbonate.

In the step (2), the molar ratio of the methanol to the dichloroethylene carbonate is 10;

in the step (2), the mass ratio of the ethylene dichlorocarbonate to the quaternary phosphonium salt catalyst is 1;

in the step (2), the mass ratio of ethylene dichlorocarbonate to ethylene carbonate is 4.

Example 4

A preparation method of dimethyl carbonate comprises the following steps:

(1) heating methanol at 58 deg.C for 8 min;

(2) adding dichloroethylene carbonate, ethylene carbonate and a quaternary phosphonium salt catalyst into the heated methanol obtained in the step (1), carrying out heat preservation reaction for 5 hours at the temperature of 55 ℃, and absorbing tail gas by utilizing diatom ooze during the reaction;

(3) and (3) after the heat preservation reaction in the step (2) is finished, obtaining the dimethyl carbonate.

In the step (2), the molar ratio of the methanol to the dichloroethylene carbonate is 7;

in the step (2), the mass ratio of the ethylene dichlorocarbonate to the quaternary phosphonium salt catalyst is 0.5;

in the step (2), the mass ratio of ethylene dichlorocarbonate to ethylene carbonate is 3.

Performance test

The compositions of the dimethyl carbonate prepared in examples 1 to 5 were measured, and the results are shown in the following table:

as can be seen from the table above, the dimethyl carbonate prepared by the method has extremely low heavy metal content and extremely low residual methanol, so that the concentration of the prepared finished product dimethyl carbonate reaches over 99.96 percent.

The present embodiment is only for explaining the present application, and it is not limited to the present application, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present application.