Methyl ethyl carbonate membrane treatment device

Abstract

Due to imbalance of methyl ethyl groups in a methyl ethyl carbonate (EMC) structure, the product is unstable and is not suitable for long-term storage, meanwhile, an intermolecular disproportionation reaction is easily generated in a heating process, dimethyl carbonate and diethyl carbonate are generated, the separation difficulty is increased, and meanwhile, the one-way product yield is reduced. The utility model provides a methyl ethyl carbonate membrane treatment device which comprises a recovery heater, a feed heater, a membrane separator, a vacuum compressor, a compressor frequency converter, a membrane separator pressure gauge, a feed thermometer, a feed temperature control valve, a compressor outlet pressure gauge and a compressor outlet pressure control valve, a cold side outlet of the feeding heater is connected with an inlet of the membrane separator; a product outlet of the membrane separator is connected with an inlet of the vacuum compressor; an outlet of the vacuum compressor is connected with a hot side inlet of the recycling heater; and a hot side outlet of the recycling heater is connected with a product delivery pipeline. The methyl ethyl carbonate is separated at a relatively low temperature, so that a higher-purity electronic-grade methyl ethyl carbonate product is obtained, the one-way yield of the methyl ethyl carbonate is increased, heat is recovered, and the operation cost is reduced.

Description

Technical Field

[0001] The utility model relates to the production field of ethyl methyl carbonate, in particular to a membrane treatment device for ethyl methyl carbonate. Background Art

[0002] Ethyl methyl carbonate (EMC), with the molecular formula C4H8O3 and molecular weight of 104.1, is a colorless transparent liquid with a slightly pungent odor. Ethyl methyl carbonate also has the following properties: melting point -55°C, boiling point 109°C, relative density 1.0 (20 / 4°C), refractive index 1.3846, flash point 23°C; insoluble in water, soluble in organic solvents such as alcohols and ethers. Ethyl methyl carbonate is a high-tech and high-value-added chemical product that has emerged in recent years. It is an excellent solvent for lithium-ion battery electrolytes and is the latest product derived from the increasing production of dimethyl carbonate and lithium-ion batteries. Ethyl methyl carbonate (EMC) can be used in many rechargeable batteries, such as being used as a co-solvent for non-aqueous electrolytes in lithium-ion metal batteries; it can also improve the performance of the battery, such as increasing the energy density of the battery, enhancing the discharge capacity, and improving the use stability and safety. At the same time, due to the presence of methyl and ethyl groups in its structure, it has the characteristics of both dimethyl carbonate and diethyl carbonate and is also a solvent for special spices and intermediates. Therefore, ethyl methyl carbonate (EMC) has good application prospects.

[0003] Due to the imbalance of methyl and ethyl groups in the structure of ethyl methyl carbonate (EMC), the product is unstable and not suitable for long-term storage. At the same time, during the heating process, intermolecular disproportionation reaction is prone to occur, generating dimethyl carbonate and diethyl carbonate, which increases the separation difficulty and reduces the single-pass product yield. The present invention provides a membrane treatment device for ethyl methyl carbonate, which separates ethyl methyl carbonate at a relatively low temperature, obtains a higher-purity electronic-grade ethyl methyl carbonate product, improves the single-pass yield of ethyl methyl carbonate, recovers heat, and reduces the operating cost. Summary of the Invention

[0004] The purpose of the utility model is to provide a membrane treatment device for ethyl methyl carbonate, which can avoid the disproportionation reaction of ethyl methyl carbonate, improve the product quality, and reduce the energy consumption.

[0005] To achieve the above object, the present utility model provides the following technical solution: A dimethyl carbonate film treatment device, comprising a recovery heater, a feed heater, a membrane separator, a vacuum compressor, a compressor frequency converter, a membrane separator pressure gauge, a feed thermometer, a feed temperature control valve, a compressor outlet pressure gauge, a compressor outlet pressure control valve, characterized in that: the cold side outlet of the recovery heater is connected to the cold side inlet of the feed heater, the cold side outlet of the feed heater is connected to the inlet of the membrane separator, the product outlet of the membrane separator is connected to the inlet of the vacuum compressor, the outlet of the vacuum compressor is connected to the hot side inlet of the recovery heater, and the hot side outlet of the recovery heater is connected to the product delivery pipeline.

[0006] The membrane separator adopts a gas separation membrane.

[0007] The feed temperature of the membrane separator is automatically controlled by the feed temperature control valve, and the feed temperature of the membrane separator is 80 - 100 °C.

[0008] The vacuum compressor adopts variable frequency automatic control of the operating pressure of the membrane separator, and the operating pressure of the membrane separator is controlled at an absolute pressure of 40 KPa - 80 KPa.

[0009] The outlet pressure of the vacuum compressor is automatically controlled by the compressor outlet pressure control valve, and the outlet pressure of the vacuum compressor is an absolute pressure of 60 KPa - 150 KPa. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a schematic diagram of a dimethyl carbonate film treatment device. Among them: 1. Recovery heater, 2. Feed heater, 3. Membrane separator, 4. Vacuum compressor, 5. Compressor frequency converter, 6. Membrane separator pressure gauge, 7. Feed thermometer, 8. Feed temperature control valve, 9. Compressor outlet pressure gauge, 10. Compressor outlet pressure control valve. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0011] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present utility model.

[0012] Replace the original rectification method for producing electronic-grade ethyl methyl carbonate in the 30,000-ton annual production device of ethyl methyl carbonate. Connect from the crude product pump of the original system to the cold-side inlet of the recovery heater. The cold-side outlet of the recovery heater is connected to the cold-side inlet of the feed heater. The cold-side outlet of the feed heater is connected to the inlet of the membrane separator. The product outlet of the membrane separator is connected to the inlet of the vacuum compressor. The outlet of the vacuum compressor is connected to the hot-side inlet of the recovery heater. The hot-side outlet of the recovery heater is connected to the product delivery pipeline. The crude product outlet of the membrane separator is connected to the recovery system of the original device for recovery and treatment. The pressure of the membrane separator is automatically controlled by the compressor frequency converter, and the feed temperature is automatically controlled by the feed temperature control valve.

[0013] The raw material liquid of ethyl methyl carbonate with a mass content of more than 99.9% is continuously and stably fed into the system at a feed rate of 4.7 t / h, and the feed temperature is controlled at 82 °C. Start the vacuum compressor, control the pressure of the membrane separator at 40 KPa (absolute pressure), and control the outlet pressure of the vacuum compressor at 60 KPa (absolute pressure). As the heat exchange amount of the recovery heater increases, the feed temperature control valve automatically closes slightly to maintain the stable feed temperature of 82 °C. Measure the quality of the raw material and the product every two hours, and count the energy consumption and yield after continuous and stable operation for 24 hours.

[0014] Slowly raise the feed temperature to 91 °C, control the pressure of the membrane separator at 60 KPa (absolute pressure), control the outlet pressure of the vacuum compressor at 80 KPa (absolute pressure), measure the quality of the raw material and the product every two hours, and count the energy consumption and yield after continuous and stable operation for 24 hours.

[0015] Slowly raise the feed temperature to 99 °C, control the pressure of the membrane separator at 80 KPa (absolute pressure), control the outlet pressure of the vacuum compressor at 100 KPa (absolute pressure), measure the quality of the raw material and the product every two hours, and count the energy consumption and yield after running for 24 hours.

[0016] The operation data before and after the transformation of the device are compared as follows:

[0017]

[0018]

[0019] Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Claims

1. A membrane treatment device for ethyl methyl carbonate, comprising a recovery heater (1), a feed heater (2), a membrane separator (3), a vacuum compressor (4), a compressor frequency converter (5), a membrane separator pressure gauge (6), a feed thermometer (7), a feed temperature control valve (8), a compressor outlet pressure gauge (9), and a compressor outlet pressure control valve (10), wherein: The cold side outlet of the recovery heater (1) is connected to the cold side inlet of the feed heater (2), the cold side outlet of the feed heater (2) is connected to the inlet of the membrane separator (3), the product outlet of the membrane separator (3) is connected to the inlet of the vacuum compressor (4), the outlet of the vacuum compressor (4) is connected to the hot side inlet of the recovery heater (1), and the hot side outlet of the recovery heater (1) is connected to the product delivery pipeline.

2. The ethyl methyl carbonate membrane treatment device according to claim 1, characterized in that: The membrane separator uses a gas separation membrane.

3. The ethyl methyl carbonate membrane treatment device according to claim 1, characterized in that: The feed temperature of the membrane separator is automatically controlled by a feed temperature control valve, and the feed temperature of the membrane separator is 80-100°C.

4. The ethyl methyl carbonate membrane treatment device according to claim 1, characterized in that: The vacuum compressor adopts frequency conversion to automatically control the operating pressure of the membrane separator, and the operating pressure of the membrane separator is controlled to have an absolute pressure of 40KPa-80KPa.

5. The ethyl methyl carbonate membrane treatment device according to claim 1, characterized in that: The outlet pressure of the vacuum compressor is automatically controlled by the compressor outlet pressure control valve, and the absolute pressure of the vacuum compressor outlet pressure is 60KPa-150KPa.

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