阅读说明：本技术 一种利用废弃物制备碳酸二甲酯的方法 (Method for preparing dimethyl carbonate by using waste ) 是由 姜飞 陈群 孙西船 翟涛 孔令文 于 2020-12-27 设计创作，主要内容包括：本发明公开了一种利用废弃物制备碳酸二甲酯的方法,包括以下步骤：1)室温下将一定量的甲醇加入到三口烧瓶中,升温至一定温度,使甲醇产生稳定回流；2)向S1中的溶液中滴加一定量的二氯代碳酸乙烯酯,保温反应,使用气相色谱监控反应过程,并利用碱液吸收尾气；3)在S2反应结束后,常压蒸馏反应液得到碳酸二甲酯；4)在S3过程中可回收过量的甲醇；本发明利用有机废弃物二氯代碳酸乙烯酯制备碳酸二甲酯,反应后的废弃物氯含量大大降低,处理简单且成本低,既可以降低三废处理成本和环保成本；得到的碳酸二甲酯又可以作为副产创造经济效益,属于废弃物资源化,降本增效,适合大规模生产。(The invention discloses a method for preparing dimethyl carbonate by using wastes, which comprises the following steps: 1) adding a certain amount of methanol into a three-neck flask at room temperature, and heating to a certain temperature to enable the methanol to generate stable reflux; 2) dropwise adding a certain amount of dichloroethylene carbonate into the solution in the S1, carrying out heat preservation reaction, monitoring the reaction process by using gas chromatography, and absorbing tail gas by using alkali liquor; 3) after the reaction of S2 is finished, distilling the reaction solution under normal pressure to obtain dimethyl carbonate; 4) excess methanol may be recovered during S3; according to the invention, the organic waste ethylene dichlorocarbonate is used for preparing the dimethyl carbonate, the chlorine content of the waste after reaction is greatly reduced, the treatment is simple, the cost is low, and the three-waste treatment cost and the environmental protection cost can be reduced; the obtained dimethyl carbonate can be used as a byproduct to create economic benefit, belongs to waste recycling, reduces cost and improves efficiency, and is suitable for large-scale production.)

1. A method for preparing dimethyl carbonate by using wastes is characterized by comprising the following steps: the method comprises the following steps:

s1, adding a certain amount of methanol solution into the three-neck flask at normal temperature, and then putting the three-neck flask into an oil bath pot for heating to enable the methanol to generate stable reflux;

s2, dropwise adding a certain amount of dichloroethylene carbonate into the refluxed solution, carrying out heat preservation reaction, monitoring the reaction process by using a gas chromatography, and absorbing tail gas by using alkali liquor;

s3, after the heat preservation reaction is finished, carrying out atmospheric distillation on the reaction liquid to obtain dimethyl carbonate;

s4, the excessive methanol in the step S3 is recovered.

2. The method for preparing dimethyl carbonate by using wastes as claimed in claim 1, wherein: and in the step S1, three ports on the three-port flask are respectively connected with a condenser, a thermometer and a constant pressure dropping funnel, tap water is used for cooling the condenser, and the temperature of the oil bath pot is set to be 55 ℃.

3. The method for preparing dimethyl carbonate by using wastes as claimed in claim 1, wherein: the mass of ethylene dichlorocarbonate added dropwise in the step S2 was 200-500g, and was added dropwise through a constant pressure dropping funnel.

4. The method for preparing dimethyl carbonate by using wastes as claimed in claim 1, wherein: the heating temperature in the step S1 is 30-60 ℃.

5. The method for preparing dimethyl carbonate by using wastes as claimed in claim 1, wherein: the equivalent ratio of methanol to dichloroethylene carbonate in step S2 is 4:1 to 6: 1.

6. The method for preparing dimethyl carbonate by using waste as claimed in claim 1 or 3, wherein: the purity of dichloroethylene carbonate in the step S2 is 75% to 98%.

Technical Field

The invention relates to the field of raw materials of lithium ion battery electrolyte additives, in particular to a preparation method of dimethyl carbonate serving as a solvent used in the preparation process of the lithium ion battery electrolyte additives.

Background

Dimethyl carbonate has good chemical reaction activity, and can be used as a raw material to develop and prepare various fine special chemicals with high added values, and can be widely applied to the fields of medicines, pesticides, synthetic materials, dyes, lubricating oil additives, food flavoring agents, electronic chemicals and the like. In addition, it can be used as solvent, gasoline additive, etc.

Chlorinated ethylene carbonate is a common raw material for preparing vinylene carbonate and fluoroethylene carbonate, chlorine gas and ethylene carbonate are subjected to substitution reaction in industry to prepare the chlorinated ethylene carbonate, and a byproduct of the chlorinated ethylene carbonate is dichloroethylene carbonate, so that the chlorinated ethylene carbonate does not have a recycling scheme with good economic benefit at present, the chlorine content of the chlorinated ethylene carbonate exceeds 45%, the waste treatment difficulty is high, the requirement on equipment is high, the treatment process is complex, and the cost is high.

Disclosure of Invention

The invention aims to provide a method for preparing dimethyl carbonate by using wastes so as to solve the technical problems in the background technology.

In order to achieve the aim, the invention provides a method for preparing dimethyl carbonate by using waste, which comprises the following steps:

s1, adding a certain amount of methanol solution into the three-neck flask at normal temperature, and then putting the three-neck flask into an oil bath pot for heating to enable the methanol to generate stable reflux;

s2, dropwise adding a certain amount of dichloroethylene carbonate into the refluxed solution, carrying out heat preservation reaction, monitoring the reaction process by using a gas chromatography, and absorbing tail gas by using alkali liquor;

s3, after the heat preservation reaction is finished, carrying out atmospheric distillation on the reaction liquid to obtain dimethyl carbonate;

s4, the excessive methanol in the step S3 is recovered.

As a further improvement of the scheme, in the step S1, three mouths of the three-mouth flask are respectively connected with a condenser pipe, a thermometer and a constant pressure dropping funnel, the condenser pipe is cooled by tap water, and the temperature of an oil bath pot is set to be 55 ℃.

As a further improvement of the above scheme, the mass of the ethylene dichlorocarbonate added dropwise in the step S2 is 200-500g, and the dropwise addition is carried out through a constant pressure dropping funnel.

As a further improvement of the scheme, the heating temperature in the step S1 is 30-60 ℃.

As a further improvement of the scheme, the equivalent ratio of the methanol to the ethylene dichlorocarbonate in the step S2 is 4: 1-6: 1.

As a further improvement of the scheme, the purity of the dichloroethylene carbonate in the step S2 is 75-98%.

The invention has the beneficial effects that: the method for preparing the dimethyl carbonate by using the waste is to prepare the dimethyl carbonate by using the organic waste ethylene dichlorocarbonate, the chlorine content of the waste after reaction is greatly reduced, the treatment is simple, the cost is low, and the three-waste treatment cost and the environmental protection cost can be reduced; the obtained dimethyl carbonate can be used as a byproduct to create economic benefit, belongs to waste recycling, reduces cost and improves efficiency, and is suitable for large-scale production.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the described embodiments of the invention, are within the scope of the invention.

The embodiment of the invention provides a method for preparing dimethyl carbonate by using waste, which comprises the following steps:

s1, adding a certain amount of methanol solution into the three-neck flask at normal temperature, and then putting the three-neck flask into an oil bath pot for heating to enable the methanol to generate stable reflux;

s2, dropwise adding a certain amount of dichloroethylene carbonate into the refluxed solution, carrying out heat preservation reaction, monitoring the reaction process by using a gas chromatography, and absorbing tail gas by using alkali liquor;

s3, after the heat preservation reaction is finished, carrying out atmospheric distillation on the reaction liquid to obtain dimethyl carbonate;

s4, the excessive methanol in the step S3 is recovered.

Example 1

Putting 280g of methanol into a 1000mL three-neck flask, putting the three-neck flask into an oil bath pan, setting the temperature of the oil bath pan to be 55 ℃, heating the three-neck flask until the methanol is stably refluxed, slowly dropwise adding 300g of dichloroethylene carbonate with the mass fraction of 93.0% by using a constant-pressure dropping funnel under stirring for two hours, continuing the heat preservation reaction, monitoring the reaction condition by using a gas chromatograph, finishing the reaction when the content of the dichloroethylene carbonate is lower than 0.5%, and finally recovering 50.1g of the methanol by reduced pressure distillation. The final product, dimethyl carbonate, was obtained in 95.35g, purity 96.56% and yield 60.2%.

Example 2

Putting 280g of methanol into a 1000mL three-neck flask, putting the three-neck flask into an oil bath pan, setting the temperature of the oil bath pan to be 55 ℃, heating the three-neck flask until the methanol is stably refluxed, slowly dropwise adding 320g of dichloroethylene carbonate with the mass fraction of 87.4% for two hours by using a constant-pressure dropping funnel under stirring, continuing the heat preservation reaction, monitoring the reaction condition by using a gas chromatograph, finishing the reaction when the content of the dichloroethylene carbonate is lower than 0.5%, and finally, carrying out reduced pressure distillation to recover 48.5g of methanol to obtain the final product, namely 97.14g of dimethyl carbonate, the purity of 95.65% and the yield of 57.95%.

Example 3

Putting 280g of methanol into a 1000mL three-neck flask, putting the three-neck flask into an oil bath pan, setting the temperature of the oil bath pan to be 55 ℃, heating the three-neck flask until the methanol is stably refluxed, slowly dropwise adding 310g of dichloroethylene carbonate with the mass fraction of 91.3% by using a constant-pressure dropping funnel under stirring for two hours, continuing the heat preservation reaction, monitoring the reaction condition by using gas chromatography, finishing the reaction when the content of the dichloroethylene carbonate is lower than 0.5%, and finally, carrying out reduced pressure distillation to recover 47.6g of methanol to obtain the final product, namely 99.34g of dimethyl carbonate, the purity of 96.2% and the yield of 58.9%.

In summary, according to the method for preparing dimethyl carbonate by using waste in the above embodiment, dimethyl carbonate is prepared by using ethylene dichlorocarbonate which is an organic waste, the chlorine content of the waste after reaction is greatly reduced, the treatment is simple, the cost is low, and the three-waste treatment cost and the environmental protection cost can be reduced; the obtained dimethyl carbonate can be used as a byproduct to create economic benefit, belongs to waste resource, reduces cost and improves efficiency, and is suitable for large-scale production

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.