Continuous production process of dimethyl sulfoxide

Abstract

The invention discloses a continuous production process of dimethyl sulfoxide, which comprises a hydrogen peroxide storage tank, a mass flow meter, a delivery pump, a micro-channel reactor, a dimethyl sulfide storage tank, a flow self-control valve, a thermometer, a pressure gauge, a cold and hot all-in-one machine, a sampling port, a multi-phase reactor, a liquid level meter, a phase splitter, an electromagnetic valve, a dimethyl sulfoxide storage tank and a water phase storage tank. Outlets of the hydrogen peroxide storage tank and the dimethyl sulfide storage tank are respectively connected to a micro-channel reactor through a mass flow meter and a delivery pump, an outlet of the micro-channel reactor is connected to a multi-phase reactor, the micro-channel reactor and the multi-phase reactor are respectively connected to a cold and hot all-in-one machine, the multi-phase reactor is connected to a phase splitter, and the phase splitter is connected to a hot and cold all-in-one machine. And the phase splitter is respectively connected to a dimethyl sulfoxide storage tank and a water phase storage tank. According to the invention, the continuous production of dimethyl sulfoxide can be realized, the problems of low production efficiency and high production cost in the existing dimethyl sulfoxide production process are solved, and the production safety is ensured.

Description

Technical Field

[0001] The invention relates to the field of chemical equipment, and in particular to a continuous production process of dimethyl sulfoxide. Technical Background

[0002] Dimethyl sulfoxide is a sulfur-containing polar organic solvent. It is widely used in the chemical industry. It can be used as a dyeing solvent, de-dyeing agent, dyeing carrier for synthetic fibers, and an absorbent for recovering acetylene and sulfur dioxide. Its preparation methods include methanol carbon disulfide method, hydrogen peroxide method and nitrogen dioxide method. At present, the industry mostly uses nitrogen dioxide oxidation method to produce dimethyl sulfoxide. Using dimethyl sulfide as raw material and hydrogen peroxide as oxidant, dimethyl sulfoxide is synthesized by optimizing process conditions such as material ratio and temperature. The by-product is water. The product is easy to purify, and the green and clean production of dimethyl sulfoxide can be achieved.

[0003] Patent CN114890924B discloses a method for preparing dimethyl sulfoxide, wherein dimethyl sulfide and hydrogen peroxide are transported into a mixer via a metering pump, and sequentially pass through one to six tubular reactors, wherein the jacket of the first tubular reactor is equipped with a hot water pipeline, and the reaction is carried out by controlling the temperature, and the unreacted dimethyl sulfide and hydrogen peroxide are sequentially reacted in two to six tubular reactors, and the reaction conditions are mild, no hazardous waste is generated, and the environment is friendly. However, the mixing effect is poor, and the two materials cannot be fully contacted and mixed. Patent CN114805145A provides a synthesis process for dimethyl sulfoxide, wherein dimethyl sulfide is used as a raw material and hydrogen peroxide is used as an oxidant, and the two materials are first passed into a membrane mixer to fully contact and mix, and then sent into a continuous flow microreactor to produce dimethyl sulfoxide. This method ensures the full reaction of dimethyl sulfide and hydrogen peroxide, but the production efficiency is low, the cost of producing dimethyl sulfoxide is high, and it is not suitable for large-scale production.

[0004] In summary, a new type of efficient synthesis method with full contact mixing is urgently needed to solve the problems of low production efficiency, complex process and high production cost in the existing dimethyl sulfoxide production process, and solve the problem of high heat release in the production process to ensure production safety. Summary of the invention

[0005] In order to solve the problems of high cost, high energy consumption, insufficient production capacity and poor safety in the existing dimethyl sulfoxide production process, the present invention provides a continuous production process of dimethyl sulfoxide.

[0006] The technical means adopted by the present invention are as follows: a continuous production process of dimethyl sulfoxide, including a hydrogen peroxide storage tank, a mass flow meter A, a delivery pump A, a microchannel reactor, a dimethyl sulfide storage tank, a mass flow meter B, a delivery pump B, a flow automatic control valve A, a flow automatic control valve B, a thermometer A, a pressure gauge A, a cold and hot integrated machine A, a sampling port A, a multiphase reactor, a thermometer B, a pressure gauge B, a cold and hot integrated machine B, a sampling port B, a liquid level meter, a phase separator, an electromagnetic valve, a dimethyl sulfoxide storage tank, and an aqueous phase storage tank. The hydrogen peroxide storage tank is divided into three branches through mass flowmeter A and delivery pump A and are respectively connected to the microchannel reactor. Flow automatic control valve A and flow automatic control valve B are respectively arranged after the branch nodes. The dimethyl sulfide storage tank is connected to the microchannel reactor through mass flowmeter B and delivery pump B. The microchannel reactor is provided with thermometer A and pressure gauge A and is connected to the cold and hot integrated machine A through oil outlet and return pipes. The microchannel reactor is connected to the multiphase reactor through sampling port A. The multiphase reactor is provided with thermometer A and pressure gauge A and is connected to the cold and hot integrated machine B through oil outlet and return pipes. The multiphase reactor is connected to the phase separator through sampling port B. The phase separator is provided with a liquid level meter. One branch of the phase separator is connected to the dimethyl sulfoxide storage tank through an electromagnetic valve, and the other branch of the phase separator is connected to the water phase storage tank.

[0007] Furthermore, the microchannel reactor is composed of six plates connected in series, and the three branches connecting the hydrogen peroxide storage tank and the microchannel reactor respectively enter the first, third and fifth plates. The flow rate of hydrogen peroxide is controlled by flow automatic control valve A and flow automatic control valve B, and the first plate enters 40%-60% of the total flow rate, the third plate enters 20%-40% of the total flow rate, and the fifth plate enters 0-20% of the total flow rate.

[0008] Furthermore, the molar ratio of the above reaction materials (hydrogen peroxide: dimethyl sulfide) is 1:1.05-1:5, preferably 1:1-1:2; the reaction temperature is 30-100°C, preferably 40-70°C, and the residence time is 0.5-30min, preferably 1-20min.

[0009] Furthermore, the multiphase reactor has a "double heat exchange" structure, and the heat exchange fluid is introduced into the hollow of the stirring shaft to realize the heat exchange of the reaction together with the jacket, which can improve the heat exchange efficiency, avoid the danger caused by excessive local temperature, and improve the safety of production;

[0010] Furthermore, the reaction chamber tube length of the multiphase reactor is much larger than the tube diameter, the aspect ratio is about 5-20, the radial thickness of the reaction material is 10mm-300mm, and baffles and closely arranged stirring paddles are arranged in the reaction chamber, which enhances the mass transfer and heat transfer effects of the materials and improves the product quality.

[0011] Since the present invention adopts the above technical solution, the technical effect produced is obvious:

[0012] 1. Dimethyl sulfide and hydrogen peroxide react to release a large amount of heat. Hydrogen peroxide enters the microchannel reactor through three branches to achieve segmented feeding and heat extraction, which improves the stability of the reaction and the safety of production;

[0013] 2. A solenoid valve is set at the outlet of the phase separator to control the entry of dimethyl sulfoxide into the dimethyl sulfoxide storage tank by utilizing the different electrical conductivity of the material. It is fast, accurate, safe and reliable.

[0014] 3. Sampling ports A and B are set after the microchannel reactor and the multiphase reactor. By sampling and testing the reaction products, the material mixing and reaction conditions can be obtained, which is convenient for adjusting various parameters;

[0015] 4. The present invention realizes the continuous synthesis of dimethyl sulfoxide by connecting a microchannel reactor and a multiphase reactor in series, simplifies the production process, improves the utilization rate of the raw material dimethyl sulfide, reduces the production cost, and has higher yield and production efficiency;

[0016] 5. Continuous feeding and discharging are realized, and production can be started or interrupted as required, which realizes the continuous control of the production process and improves production capacity; BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the continuous synthesis process of dimethyl sulfoxide.

[0018] Description of the symbols in the figure

[0019] 1 Hydrogen peroxide storage tank, 2 mass flow meter A, 3 delivery pump A, 4 microchannel reactor, 5 dimethyl sulfide storage tank, 6 mass flow meter B, 7 delivery pump B, 8 flow automatic control valve A, 9 flow automatic control valve B, 10 thermometer A, 11 pressure gauge A, 12 hot and cold integrated machine A, 13 sampling port A, 14 multiphase reactor, 15 thermometer B, 16 pressure gauge B, 17 hot and cold integrated machine B, 18 sampling port B, 19 liquid level meter, 20 phase separator, 21 solenoid valve, 22 dimethyl sulfoxide storage tank, 23 water phase storage tank. DETAILED DESCRIPTION

[0020] The present invention will be further described below through the following embodiments in conjunction with the accompanying drawings.

[0021] See also Figure 1A continuous production process of dimethyl sulfoxide includes a hydrogen peroxide storage tank 1, a mass flow meter A2, a delivery pump A3, a microchannel reactor 4, a dimethyl sulfide storage tank 5, a mass flow meter B6, a delivery pump B7, a flow automatic control valve A8, a flow automatic control valve B9, a thermometer A10, a pressure gauge A11, a cold and hot integrated machine A12, a sampling port A13, a multiphase reactor 14, a thermometer B15, a pressure gauge B16, a cold and hot integrated machine B17, a sampling port B18, a liquid level meter 19, a phase separator 20, a solenoid valve 21, a dimethyl sulfoxide storage tank 22, and an aqueous phase storage tank 23. The hydrogen peroxide storage tank 1 is divided into three branches through a mass flow meter A2 and a delivery pump A3, which are respectively connected to the microchannel reactor 4. A flow automatic control valve A8 and a flow automatic control valve B9 are respectively arranged after the branch nodes. The dimethyl sulfide storage tank 5 is connected to the microchannel reactor 4 through a mass flow meter B6 and a delivery pump B7. The microchannel reactor 4 is provided with a thermometer A10 and a pressure gauge A11 and is connected to the hot and cold integrated machine A12 through an oil outlet pipe and an oil return pipe. The microchannel reactor 4 is connected to the hot and cold integrated machine A12 through an oil outlet pipe and an oil return pipe. The sampling port A is connected to the multiphase reactor 14. The multiphase reactor 14 is provided with a thermometer B15 and a pressure gauge B16 and is connected to the hot and cold integrated machine B17 through an oil outlet pipe and an oil return pipe. The multiphase reactor 14 is connected to a phase separator 20 through a sampling port B18. The phase separator 20 is provided with a liquid level meter 19. The phase separator 20 is divided into two branches. One branch of the phase separator is connected to a dimethyl sulfoxide storage tank 22 through a solenoid valve 21, and the other branch of the phase separator is connected to a water phase storage tank 23.

[0022] The specific working process of the present invention is as follows:

[0023] The hydrogen peroxide with a mass fraction of 20%-40% in the hydrogen peroxide storage tank 1 is divided into three branches and enters the microchannel reactor 4 through the mass flow meter A2 at a flow rate of 40-90ml / min through the delivery pump A3. The flow rate of the hydrogen peroxide entering the three branches is controlled by the flow automatic control valve A8 and the flow automatic control valve B9. The dimethyl sulfide in the dimethyl sulfide storage tank 5 is passed through the mass flow meter B6 at a flow rate of 30-70ml / min through the delivery pump B7 to enter the microchannel reactor 4 and fully contact and mix with the hydrogen peroxide. The heat required for the reaction is realized by the hot and cold integrated machine A12, and the temperature is controlled at 30-1 00℃, the temperature and pressure of the microchannel reactor are measured by thermometer A10 and pressure gauge A11 respectively, the reaction product enters the multiphase reactor 14 through the sampling port A13 for delayed reaction, the reaction temperature is controlled by the hot and cold integrated machine B17, the reaction temperature and pressure are monitored by thermometer B15 and pressure gauge B16 respectively, the mixed product of dimethyl sulfoxide and aqueous phase generated by the reaction is separated in the phase separator 20 through the sampling port B18, the liquid level of the mixed product in the phase separator 20 is monitored by the liquid level meter 19, wherein dimethyl sulfoxide flows into the dimethyl sulfoxide storage tank 22 through the solenoid valve 21, and the aqueous phase flows into the aqueous phase storage tank 23.

[0024] Example 1

[0025] Hydrogen peroxide with a mass fraction of 40% and dimethyl sulfide are introduced into a microchannel reactor at a molar ratio of 1:1.5, wherein the hydrogen peroxide introduced into the first, second and third pieces of the microchannel reactor accounts for 50%, 30% and 20% of the total flow of hydrogen peroxide respectively, and the residence time of the material in the microchannel reactor is controlled to be 20s. Samples are taken from the sampling port at the rear of the multiphase reactor for gas chromatography analysis, and the selectivity of dimethyl sulfoxide is 99.5%.

[0026] Example 2

[0027] Hydrogen peroxide and dimethyl sulfide with a mass fraction of 30% are introduced into a microchannel reactor at a molar ratio of 1:1.5, wherein the hydrogen peroxide introduced into the first, second and third pieces of the microchannel reactor accounts for 50%, 30% and 20% of the total flow of hydrogen peroxide respectively, and the residence time of the material in the microchannel reactor is controlled to be 20s. Samples are taken from the sampling port at the rear of the multiphase reactor for gas chromatography analysis, and the selectivity of dimethyl sulfoxide is 99.7%.

[0028] Example 3

[0029] Hydrogen peroxide and dimethyl sulfide with a mass fraction of 30% are introduced into a microchannel reactor at a molar ratio of 1:1.5, wherein the hydrogen peroxide introduced into the first, second and third pieces of the microchannel reactor accounts for 50%, 30% and 20% of the total flow of hydrogen peroxide respectively, and the residence time of the material in the microchannel reactor is controlled to be 30s. Samples are taken from the rear sampling port of the multiphase reactor for gas chromatography analysis, and the selectivity of dimethyl sulfoxide is 99.9%.

[0030] The above embodiments are only used to illustrate and not to limit the technical solutions of the present invention. Any modification or partial replacement that does not deviate from the spirit of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A continuous production process of dimethyl sulfoxide, comprising a hydrogen peroxide storage tank 1, a mass flow meter A2, a delivery pump A3, a microchannel reactor 4, a dimethyl sulfide storage tank 5, a mass flow meter B6, a delivery pump B7, a flow automatic control valve A8, a flow automatic control valve B9, a thermometer A10, a pressure gauge A11, a cold and hot integrated machine A12, a sampling port A13, a multiphase reactor 14, a thermometer B15, a pressure gauge B16, a cold and hot integrated machine B17, a sampling port B18, a liquid level meter 19, a phase separator 20, a solenoid valve 21, a dimethyl sulfoxide storage tank 22, and a water phase storage tank 23. The hydrogen peroxide storage tank 1 is divided into three branches through the mass flow meter A2 and the delivery pump A3, which are respectively connected to the microchannel reactor 4. The flow automatic control valve A8 and the flow automatic control valve A9 are respectively arranged after the branch node. B9, the above-mentioned dimethyl sulfide storage tank 5 is connected to the microchannel reactor 4 through the mass flow meter B6 and the delivery pump B7. The above-mentioned microchannel reactor 4 is provided with a thermometer A10 and a pressure gauge A11 and is connected to the cold and hot integrated machine A12 through an oil outlet pipe and an oil return pipe. The above-mentioned microchannel reactor 4 is connected to the multiphase reactor 14 through the sampling port A. The above-mentioned multiphase reactor 14 is provided with a thermometer B15 and a pressure gauge B16 and is connected to the cold and hot integrated machine B17 through an oil outlet pipe and an oil return pipe. The above-mentioned multiphase reactor 14 is connected to the phase separator 20 through the sampling port B18. The above-mentioned phase separator 20 is provided with a liquid level meter 19. The above-mentioned phase separator 20 is divided into two branches. One branch of the above-mentioned phase separator is connected to the dimethyl sulfoxide storage tank 22 through the solenoid valve 21, and the other branch of the above-mentioned phase separator is connected to the water phase storage tank 23.

2. A continuous production process of dimethyl sulfoxide according to claim 1, characterized in that: The microchannel reactor 4 is composed of six plates connected in series. The three branches connecting the hydrogen peroxide storage tank 1 and the microchannel reactor 4 enter the 1st, 3rd and 5th plates respectively. The flow rate of hydrogen peroxide is controlled by the flow automatic control valve A8 and the flow automatic control valve B9. The 1st plate enters 40%-60% of the total flow rate, the 3rd plate enters 20%-40% of the total flow rate, and the 5th plate enters 0-20% of the total flow rate.

3. A continuous production process of dimethyl sulfoxide according to claim 1, characterized in that: The molar ratio of the reaction materials (hydrogen peroxide: dimethyl sulfide) is 1:1.05-1:5, preferably 1:1-1:2; the reaction temperature is 30-100°C, preferably 40-70°C; the residence time is 0.5-30min, preferably 1-20min.

4. A continuous production process of dimethyl sulfoxide according to claim 1, characterized in that: The multiphase reactor 14 is a "double heat exchange" structure. The heat exchange fluid is passed into the hollow of the stirring shaft, and the heat exchange of the reaction is achieved together with the jacket, which can improve the heat exchange efficiency, avoid the danger caused by local excessive temperature, and improve the safety of production.

5. A continuous production process of dimethyl sulfoxide according to claim 1, characterized in that: The reaction chamber tube length of the multiphase reactor 14 is much larger than the tube diameter, the aspect ratio is about 5-20, the radial thickness of the reaction material is 10mm-300mm, and baffles and closely arranged stirring paddles are arranged in the reaction chamber, which enhances the mass transfer and heat transfer effect of the material and improves the product quality.

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