A device for continuously preparing dimethyl sulfoxide and a method for preparing the same

Abstract

The invention relates to the technical field of organic synthesis, and specifically discloses a device for continuously preparing dimethyl sulfoxide and a preparation method thereof. The device comprises: a methyl sulfide synthesis reactor, a methyl sulfide distillation tower, a methyl sulfide buffer tank, a microreactor, a multiphase reactor, a flash tank, a dimethyl sulfoxide crude removal tower and a dimethyl sulfoxide distillation feed pump which are sequentially connected and arranged, and a nitrogen heating unit and a molten salt heating unit are arranged on the methyl sulfide synthesis reactor; the device for continuously preparing dimethyl sulfoxide and the preparation method thereof, by rotating a catalytic cylinder in the methyl sulfide synthesis reactor, the catalyst can continuously change its position, thereby increasing the contact area with the reactant, and when the catalytic cylinder is rotating, the catalyst is flipped up and down by a lifting mechanism, and compared with the heating of the catalyst at a fixed position, the heating of the catalyst during flipping can reduce the heating efficiency of the catalyst, thereby preventing the catalyst from being heated too quickly and reducing its activity.

Description

Technical Field

[0001] The invention relates to the technical field of organic synthesis, and in particular to a device for continuously preparing dimethyl sulfoxide and a preparation method thereof. Background Art

[0002] Dimethyl sulfoxide (DMSO) is a non-proton polar solvent. Due to its special solvent effect on chemical reactions and its solubility characteristics for many substances, it has always been called the "universal solvent". In addition, in medicine, it has the effects of anti-inflammatory, analgesic, diuretic, sedative and promoting wound healing. It has a strong penetration ability to the body and has a carrying and synergistic effect on other drugs. Therefore, DMSO is widely used in the petroleum, chemical, pharmaceutical, electronic, synthetic fiber, plastic, printing and dyeing industries.

[0003] There are two methods for producing dimethyl sulfoxide using dimethyl sulfide as raw material: oxidation method and electrolysis method. Among them, the nitric acid oxidation method is seriously corrosive to equipment and requires a large amount of alkali to neutralize excess nitric acid, which causes serious environmental pollution; the ozone oxidation method has a low conversion rate of only 26% to 28%; the nitrogen dioxide method and electrolysis method are commonly used methods at home and abroad, with mature processes but large investments, especially the nitrogen dioxide method, which pollutes the environment and produces waste salt; the hydrogen peroxide method has mild reaction conditions, simple equipment and process routes, and does not require alkali neutralization, and can be directly distilled to obtain it. It is a green chemistry with high economy, high resource utilization, and basically no pollution to the environment.

[0004] In the process of continuously preparing dimethyl sulfoxide by the hydrogen peroxide method in the prior art, the catalyst is heated too quickly, which easily leads to a decrease in catalyst activity. In particular, when the catalyst is in a fixed position, the catalyst located in the outer layer is heated faster than the catalyst in the inner layer, which is more likely to lead to a decrease in catalyst activity, resulting in a large difference in activity between the inner and outer layers of the catalyst, affecting the reaction effect. Summary of the invention

[0005] The present invention provides a device for continuously preparing dimethyl sulfoxide and a preparation method thereof, aiming to solve the problem in the related art that when the position of the catalyst is fixed, the catalyst located in the outer layer is heated faster than the catalyst in the inner layer, which easily leads to a decrease in the activity of the outer layer catalyst and a large difference in the activity of the inner and outer layers of the catalyst.

[0006] The device for continuously preparing dimethyl sulfoxide of the present invention comprises a methyl sulfide synthesis reactor, a methyl sulfide distillation tower, a methyl sulfide buffer tank, a microreactor, a multiphase reactor, a flash tank, a dimethyl sulfoxide crude removal tower and a dimethyl sulfoxide distillation feed pump which are sequentially connected and arranged; a nitrogen heating unit and a molten salt heating unit are arranged on the methyl sulfide synthesis reactor to heat the methyl sulfide synthesis reactor;

[0007] A catalytic cylinder is arranged inside the methyl sulfide synthesis reactor, and can rotate and move relative to the methyl sulfide synthesis reactor. A catalytic chamber and a lifting chamber are arranged inside the catalytic cylinder. An upper opening and a lower opening are arranged between the catalytic chamber and the lifting chamber, respectively. A lifting mechanism is arranged in the lifting chamber, and is used to push the catalyst to move toward the upper opening when the catalytic cylinder rotates.

[0008] The lifting mechanism includes a Jiaolong conveying shaft, which is rotatably installed inside the lifting chamber and can rotate with the movement of the catalytic cylinder. A baffle is installed between the catalytic chamber and the lifting chamber to slide up and down, and the size of the upper opening can be adjusted.

[0009] The effect is that after the methyl sulfide synthesis reactor is heated to the reaction temperature by the nitrogen heating unit and the molten salt heating unit in sequence, methanol and H2S are transported to the methyl sulfide synthesis reactor for synthesis reaction to generate methyl sulfide, a small amount of methyl mercaptan and water. During the reaction, the catalyst can be continuously changed position by the rotation of the catalytic tube to increase the contact area with the reactants. During the rotation of the catalytic tube, the catalyst of the lower layer is transported to the upper layer by the lifting mechanism, and then the catalyst is flipped up and down to avoid the outer catalyst being heated too quickly and the activity being reduced due to the fixed position of the catalyst, thereby ensuring that the inner and outer catalysts can be heated relatively evenly, thereby improving the reaction effect.

[0010] Preferably, the nitrogen heating unit includes a nitrogen circulation fan and a nitrogen electric heater, the nitrogen circulation fan, the nitrogen electric heater and the methyl sulfide synthesis reactor are connected through a nitrogen circulation pipeline, and the molten salt heating unit includes a molten salt tank and a molten salt pump, the molten salt tank, the molten salt pump and the methyl sulfide synthesis reactor are connected through a molten salt circulation pipeline, which has the effect that after the nitrogen is heated by the nitrogen electric heater, the methyl sulfide synthesis reactor is initially heated by the nitrogen, and then the methyl sulfide synthesis reactor is heated to the reaction temperature by the molten salt tank and the molten salt pump through the molten salt, and the methyl sulfide synthesis reactor is effectively mixed by the nitrogen waste heat and the molten salt heating, thereby avoiding the catalyst from heating up too quickly, resulting in a decrease in catalyst activity or even a reduction in service life.

[0011] Preferably, the lifting mechanism also includes a transmission gear and a ring gear. The transmission gear is fixed at the end of the Jiaolong conveying shaft, and the ring gear is fixedly installed on the top wall of the methyl sulfide synthesis reactor, and the ring gear is meshed with the transmission gear. The effect is that when the Jiaolong conveying shaft moves following the catalytic cylinder, the ring gear pushes the transmission gear to rotate the Jiaolong conveying shaft, turning the catalyst on the bottom layer to the upper layer, ensuring that the catalyst is evenly heated.

[0012] Preferably, a driving mechanism is provided in the methyl sulfide synthesis reactor for driving the catalytic cartridge to rotate in the methyl sulfide synthesis reactor, the driving mechanism comprises a motor, a rotating shaft and a connecting rod, the rotating shaft is rotatably assembled in the methyl sulfide synthesis reactor, the motor is fixedly mounted on the top of the methyl sulfide synthesis reactor, and the output end of the motor is fixed to the end of the rotating shaft, the connecting rod is fixed on the rotating shaft, and the catalytic cartridge is fixedly mounted on the end of the connecting rod, the effect of which is that the rotating shaft can be driven by the motor to rotate, so that the connecting rod moves with the catalytic cartridge, and the catalytic cartridge rotates synchronously with the rotating shaft.

[0013] Preferably, a push ring and a cylinder are provided on the rotating shaft. The push ring is slidably assembled on the outside of the rotating shaft, the cylinder is fixedly mounted on the outer wall of the rotating shaft, and the telescopic end of the cylinder is fixed on the push ring. The effect is that the push ring can be driven by the cylinder to move up and down, so that the baffle can slide up and down between the catalytic chamber and the lifting chamber to adjust the size of the upper opening, thereby adjusting the flipping efficiency of the catalyst.

[0014] Preferably, a steam heater is provided on one side of the dimethyl sulfide synthesis reactor to heat the mixed gas of methanol and H2S, and the steam heater is connected to the dimethyl sulfide distillation tower.

[0015] Preferably, a methyl sulfide discharge pump is provided between the methyl sulfide distillation tower and the methyl sulfide buffer tank, which is used to transport the methyl sulfide after distillation to the methyl sulfide buffer tank, a methyl sulfide feed pump and a methyl sulfide preheater are respectively provided between the methyl sulfide buffer tank and the microreactor, a hydrogen peroxide buffer tank is provided on one side of the microreactor, and a hydrogen peroxide feed pump is provided between the microreactor and the hydrogen peroxide buffer tank.

[0016] Preferably, a crude dimethyl sulfoxide feed pump is arranged between the flash tank and the dimethyl sulfoxide crude stripping tower, a crude stripping tower reflux tank is arranged on the top of the dimethyl sulfoxide crude stripping tower, a crude stripping tower condenser is arranged between the crude stripping tower reflux tank and the dimethyl sulfoxide crude stripping tower, a crude stripping tower reflux pump is arranged outside the crude stripping tower reflux tank, and one end of the crude stripping tower reflux pump away from the crude stripping tower reflux tank is respectively connected to the dimethyl sulfoxide crude stripping tower and the methyl sulfide buffer tank.

[0017] Preferably, a dimethyl sulfoxide distillation feed pump is provided at the bottom of the dimethyl sulfoxide crude removal tower, and the output end of the dimethyl sulfoxide distillation feed pump is connected to the dimethyl sulfoxide distillation equipment.

[0018] A method for continuously preparing dimethyl sulfoxide comprises the following steps:

[0019] S1. Nitrogen is pressurized by a nitrogen circulation fan and then enters a nitrogen electric heater for heating. After the nitrogen circulates and heats the methyl sulfide synthesis reactor to 180°C, the nitrogen heating is stopped, and then the molten salt pump is started. The molten salt enters the methyl sulfide synthesis reactor from the molten salt tank and continues to be heated. The methyl sulfide synthesis reactor is circulated and heated to 360°C.

[0020] S2, the steam heater heats the mixed gas of methanol and H2S, and the heated methanol and H2S enter the dimethyl sulfide synthesis reactor, the feed molar ratio of methanol to H2S is 2:1, the pressure is 0.2MPA, and the temperature is 360°C;

[0021] S3, driving the catalytic cylinder to rotate and flipping the catalyst up and down at the same time, so that the catalyst is evenly contacted with methanol and H2S, and methanol and H2S react to generate methyl sulfide, a small amount of methyl mercaptan and water;

[0022] S4, sending the cooled methyl sulfide to a methyl sulfide distillation tower, returning the light components methyl mercaptan and H2S at the top of the tower to the steam heater, and sending the methyl sulfide at the bottom of the tower to a methyl sulfide buffer tank;

[0023] S5, the hydrogen peroxide in the hydrogen peroxide buffer tank is fed into the microreactor by a hydrogen peroxide feed pump, the methyl sulfide in the methyl sulfide buffer tank is fed to the methyl sulfide preheater by a methyl sulfide feed pump, preheated to 50°C, and then enters the microreactor for reaction to generate crude dimethyl sulfoxide, and the unreacted hydrogen peroxide and methyl sulfide enter the multiphase reactor along with the crude dimethyl sulfoxide to continue the reaction, and the feed molar ratio of hydrogen peroxide to methyl sulfide is controlled to be 2:1.05, the reaction temperature is 55-65°C, and the reaction pressure is 0.2MPA, so that the hydrogen peroxide conversion rate reaches 99%, and the methyl sulfide conversion rate reaches more than 95%;

[0024] S6. The crude dimethyl sulfoxide at the outlet of the multiphase reactor enters a flash tank. After flash evaporation, the dimethyl sulfoxide is sent to a dimethyl sulfoxide crude stripping tower. The light component methyl sulfide at the top of the tower flows into the reflux tank of the crude stripping tower through the crude stripping tower condenser. A part of the methyl sulfide in the reflux tank of the crude stripping tower is refluxed to the dimethyl sulfoxide crude stripping tower by a crude stripping tower reflux pump, and the other part is sent to a methyl sulfide buffer tank for recycling. The dimethyl sulfoxide at the bottom of the dimethyl sulfoxide crude stripping tower is sent to the dimethyl sulfoxide distillation equipment for further refining by a dimethyl sulfoxide distillation feed pump.

[0025] The effect is that the methyl sulfide synthesis reactor is heated by nitrogen waste heat and molten salt heating, which can avoid excessive heating in the methyl sulfide synthesis reactor to avoid the catalyst activity reduction due to excessive heating. At the same time, during the reaction process, the catalyst is constantly flipped up and down to reduce the heating rate of the catalyst and ensure that the inner and outer layers of the catalyst can be heated evenly, further avoiding the reduction of catalyst activity and improving the reaction effect.

[0026] Beneficial effects:

[0027] 1. When the present invention is in use, the catalyst can be continuously changed in position by rotating the catalyst cylinder in the dimethyl sulfide synthesis reactor, thereby increasing the contact area with the reactants. In addition, during the rotation of the catalyst cylinder, the catalyst is flipped up and down by the lifting mechanism. Compared with the heating of the catalyst in a fixed position, heating the catalyst during flipping can reduce the heating efficiency of the catalyst, thereby avoiding the catalyst from being heated too quickly and reducing its activity, and ensuring that the inner and outer layers of the catalyst can be heated relatively evenly, so that the activities of the inner and outer layers of the catalyst remain consistent, thereby improving the reaction effect.

[0028] 2. When the present invention is in use, the height of the push ring is adjusted by the cylinder, and then the size of the upper opening of the baffle is adjusted, so that the lifting height of the catalyst in the lifting mechanism can be changed, and then the turning efficiency of the catalyst can be adjusted.

[0029] 3. When the present invention is in use, the methyl sulfide synthesis reactor is heated by nitrogen waste heat and molten salt heating, which can better avoid the problem of catalyst activity reduction or even shortened service life due to excessively rapid catalyst heating.

[0030] 4. When the present invention is used, dimethyl sulfide and hydrogen peroxide are metered and mixed into a reactor, and then enter a microreactor and a multiphase reactor in sequence, wherein the amount of dimethyl sulfide added is controlled to be slightly excessive to ensure that the hydrogen peroxide reacts completely and prevent the decomposition of the hydrogen peroxide. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a structural schematic diagram of the present invention.

[0032] Figure 2 It is a front cross-sectional view of a methyl sulfide synthesis reactor of the present invention.

[0033] Figure 3 It is a structural schematic diagram of the catalytic cartridge of the present invention.

[0034] Figure 4 It is a structural schematic diagram of the baffle and the push ring of the present invention.

[0035] Reference numerals:

[0036] 1. Steam heater; 2. Methyl sulfide synthesis reactor; 200. Catalytic cylinder; 201. Catalytic chamber; 202. Lifting chamber; 203. Upper opening; 204. Lower opening; 205. Motor; 206. Rotating shaft; 207. Connecting rod; 208. Jiaolong conveying shaft; 209. Transmission gear; 210. Gear ring; 211. Baffle; 212. Push ring; 213. Cylinder; 3. Molten salt tank; 4. Molten salt pump; 5. Nitrogen circulation fan; 6. Nitrogen electric heater; 7. , methyl sulfide distillation tower; 8, methyl sulfide discharge pump; 9, hydrogen peroxide buffer tank; 10, methyl sulfide buffer tank; 11, hydrogen peroxide feed pump; 12, methyl sulfide feed pump; 13, methyl sulfide preheater; 14, microreactor; 15, multiphase reactor; 16, flash tank; 17, crude dimethyl sulfoxide feed pump; 18, crude stripping tower condenser; 19, crude stripping tower reflux tank; 20, crude stripping tower reflux pump; 21, dimethyl sulfoxide crude stripping tower; 22, dimethyl sulfoxide distillation feed pump. DETAILED DESCRIPTION

[0037] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0038] Embodiment 1:

[0039] like Figures 1 to 4 As shown, the device for continuously preparing dimethyl sulfoxide of the present invention comprises a methyl sulfide synthesis reactor 2, a methyl sulfide distillation tower 7, a methyl sulfide buffer tank 10, a microreactor 14, a multiphase reactor 15, a flash tank 16, a dimethyl sulfoxide crude removal tower 21, and a dimethyl sulfoxide distillation feed pump 22, which are sequentially connected and arranged. A heating mechanism is provided on the methyl sulfide synthesis reactor 2 for heating the methyl sulfide synthesis reactor 2 to facilitate the synthesis of methyl sulfide.

[0040] A steam heater 1 is provided on one side of the methyl sulfide synthesis reactor 2, which can heat the mixed gas of methanol and H2S to ensure that the methanol and H2S are evenly mixed to meet the methyl sulfide synthesis reaction conditions, and then the mixed gas is transported to the methyl sulfide synthesis reactor 2 for synthesis reaction. The steam heater 1 is connected to the methyl sulfide distillation tower 7, and the methyl mercaptan and H2S in the methyl sulfide distillation tower 7 can be returned to the steam heater 1.

[0041] A catalytic cylinder 200 is arranged inside the methyl sulfide synthesis reactor 2. The catalytic cylinder 200 is a mesh cylinder that can rotate and move relative to the methyl sulfide synthesis reactor 2. A catalytic chamber 201 and a lifting chamber 202 are arranged inside the catalytic cylinder 200. The catalytic chamber 201 is used to hold the catalyst to promote the synthesis of methyl sulfide. The lifting chamber 202 can lift the catalyst at the bottom of the catalytic chamber 201 and flip the catalyst in the catalytic chamber 201 up and down to ensure uniform heating of the catalyst and prevent the outer catalyst from losing its activity due to excessive heating.

[0042] An upper opening 203 and a lower opening 204 are respectively provided between the catalytic chamber 201 and the lifting chamber 202, so that the upper and lower ends of the catalytic chamber 201 and the lifting chamber 202 are connected to each other, and the catalyst in the catalytic chamber 201 can enter the lifting chamber 202 from the lower opening 204, and then return to the catalytic chamber 201 from the top after being lifted to the upper opening 203 in the lifting chamber 202, thereby realizing the flipping of the catalyst.

[0043] A driving mechanism is provided in the methyl sulfide synthesis reactor 2 for driving the catalyst cylinder 200 to rotate in the methyl sulfide synthesis reactor 2. A lifting mechanism is provided in the lifting chamber 202 for pushing the catalyst to move toward the upper opening 203 during the rotation of the catalyst cylinder 200. An adjusting mechanism is provided on the catalyst cylinder 200 for adjusting the size of the upper opening 203 to change the lifting height of the catalyst and then adjust the flipping efficiency of the catalyst.

[0044] The driving mechanism includes a motor 205, a rotating shaft 206 and a connecting rod 207. The rotating shaft 206 is rotatably assembled in the methyl sulfide synthesis reactor 2. The motor 205 is fixedly installed on the top of the methyl sulfide synthesis reactor 2, and the output end of the motor 205 is fixed to the end of the rotating shaft 206. The connecting rod 207 is fixed on the rotating shaft 206, and the catalytic cartridge 200 is fixedly installed at the end of the connecting rod 207. The rotating shaft 206 rotates under the drive of the motor 205, and the catalytic cartridge 200 is driven to rotate by the connecting rod 207.

[0045] The lifting mechanism includes a Jiaolong conveying shaft 208, a transmission gear 209 and a ring gear 210. The Jiaolong conveying shaft 208 is rotatably assembled inside the lifting chamber 202, the transmission gear 209 is fixed at the end of the Jiaolong conveying shaft 208, the ring gear 210 is fixedly installed on the top wall of the methyl sulfide synthesis reactor 2, and the ring gear 210 is meshed with the transmission gear 209, so that the Jiaolong conveying shaft 208 moves with the transmission gear 209 during the rotation of the catalytic cartridge 200, and the ring gear 210 drives the transmission gear 209 to rotate, so that the Jiaolong conveying shaft 208 rotates in the lifting chamber 202, pushing the catalyst to rise in the lifting chamber 202.

[0046] The adjusting mechanism includes a baffle 211, a push ring 212 and a cylinder 213. The baffle 211 is slidably assembled between the catalyst chamber 201 and the lifting chamber 202, and the top of the baffle 211 extends into the upper opening 203. The push ring 212 is slidably assembled outside the rotating shaft 206, and the baffle 211 and the push ring 212 are fixed. The cylinder 213 is fixedly installed on the rotating shaft 206, and the telescopic end of the cylinder 213 is fixed to the push ring 212. The push ring 212 can be pushed by the cylinder 213 to slide, so that the push ring 212 drives the baffle 211 to rise and fall, so as to adjust the length of the baffle 211 extending into the upper opening 203, so as to change the size of the upper opening 203, and then adjust the lifting height of the catalyst in the lifting chamber 202, and then change the flipping rate of the catalyst.

[0047] The heating mechanism includes a nitrogen heating unit and a molten salt heating unit, which are used to heat the methyl sulfide synthesis reactor 2. The methyl sulfide synthesis reactor 2 can be initially heated by the nitrogen heating unit and then replaced by the molten salt heating unit.

[0048] The nitrogen heating unit includes a nitrogen circulation fan 5 and a nitrogen electric heater 6. The nitrogen circulation fan 5, the nitrogen electric heater 6 and the dimethyl sulfide synthesis reactor 2 are connected through a nitrogen circulation pipeline. The nitrogen is pressurized by the nitrogen circulation fan 5 and then transported to the nitrogen electric heater 6 for heating. The heated nitrogen is then transported to the dimethyl sulfide synthesis reactor 2 for heating. The nitrogen then returns to the nitrogen circulation fan 5 through the nitrogen circulation pipeline and is again transported to the nitrogen electric heater 6, thereby cyclically heating the dimethyl sulfide synthesis reactor 2 to a suitable temperature.

[0049] The molten salt heating unit includes a molten salt tank 3 and a molten salt pump 4. The molten salt tank 3, the molten salt pump 4 and the dimethyl sulfide synthesis reactor 2 are connected through a molten salt circulation pipeline. The molten salt in the molten salt tank 3 is transported to the dimethyl sulfide synthesis reactor 2 by the molten salt pump 4 for heating. Then, the molten salt returns to the molten salt tank 3 through the molten salt circulation pipeline and is heated again, thereby circulating to heat the dimethyl sulfide synthesis reactor 2.

[0050] A methyl sulfide discharge pump 8 is provided between the methyl sulfide distillation tower 7 and the methyl sulfide buffer tank 10 for conveying the methyl sulfide after distillation to the methyl sulfide buffer tank 10 .

[0051] A methyl sulfide feed pump 12 and a methyl sulfide preheater 13 are respectively arranged between the methyl sulfide buffer tank 10 and the microreactor 14 . The methyl sulfide feed pump 12 can extract the methyl sulfide in the methyl sulfide buffer tank 10 to the methyl sulfide preheater 13 , and then transport it to the microreactor 14 after preheating.

[0052] A hydrogen peroxide buffer tank 9 is provided on one side of the microreactor 14, and a hydrogen peroxide feed pump 11 is provided between the microreactor 14 and the hydrogen peroxide buffer tank 9. After the hydrogen peroxide is buffered in the hydrogen peroxide buffer tank 9, the hydrogen peroxide feed pump 11 can pump out the hydrogen peroxide and transport it to the inside of the microreactor 14 to react with dimethyl sulfide.

[0053] The microreactor 14 is a microchannel reaction device, and the microreactor 14 is connected to the refrigerant pipeline. The microreactor 14 can be used to effectively control the mixing of reaction materials and the mass transfer and heat transfer processes.

[0054] The multiphase reactor 15 is provided with a jacket, and the jacket is connected to the refrigerant pipeline. A stirring system is provided in the middle of the multiphase reactor 15, and the strong shear force brought by high-speed stirring is used to break and mix the materials flowing on the inner wall of the reactor, so as to achieve the purpose of efficient mixing and rapid reaction. The multiphase reactor 15 adopts an internal and external double heat exchange structure, and the central stirring system and the outer jacket have a double layer effect to expand the heat exchange area. It is suitable for homogeneous, heterogeneous or multiphase reactions, and can effectively increase the reaction interface and promote reaction mass transfer.

[0055] A crude dimethyl sulfoxide feed pump 17 is provided between the flash tank 16 and the dimethyl sulfoxide crude removal tower 21 for conveying the crude dimethyl sulfoxide in the flash tank 16 to the dimethyl sulfoxide crude removal tower 21 for treatment.

[0056] A crude stripping tower reflux tank 19 is arranged on the top of the dimethyl sulfoxide crude stripping tower 21, a crude stripping tower condenser 18 is arranged between the crude stripping tower reflux tank 19 and the dimethyl sulfoxide crude stripping tower 21, a crude stripping tower reflux pump 20 is arranged on the outside of the crude stripping tower reflux tank 19, and one end of the crude stripping tower reflux pump 20 away from the crude stripping tower reflux tank 19 is respectively connected to the dimethyl sulfoxide crude stripping tower 21 and the methyl sulfide buffer tank 10, methyl sulfide flows into the crude stripping tower reflux tank 19 through the crude stripping tower condenser 18, and a part of the methyl sulfide is sent back to the dimethyl sulfoxide crude stripping tower 21 by the crude stripping tower reflux pump 20, and the other part of the methyl sulfide is transported to the methyl sulfide buffer tank 10 for recycling.

[0057] A dimethyl sulfoxide distillation feed pump 22 is provided at the bottom of the dimethyl sulfoxide crude removal tower 21, and the output end of the dimethyl sulfoxide distillation feed pump 22 is connected to the dimethyl sulfoxide distillation equipment. The dimethyl sulfoxide in the dimethyl sulfoxide crude removal tower 21 can be extracted by the dimethyl sulfoxide distillation feed pump 22 and transported to the dimethyl sulfoxide distillation equipment for distillation treatment and further refining.

[0058] The method for continuously preparing dimethyl sulfoxide of the present invention comprises:

[0059] S1, nitrogen is pressurized by the nitrogen circulation fan 5 and enters the nitrogen electric heater 6, the heated nitrogen enters the methyl sulfide synthesis reactor 2, the nitrogen is discharged from the methyl sulfide synthesis reactor 2 and returns to the nitrogen circulation fan 5, the nitrogen circulates and heats the methyl sulfide synthesis reactor 2 to 180°C, the nitrogen heating is stopped, the molten salt pump 4 is started, the molten salt enters the methyl sulfide synthesis reactor 2 from the molten salt tank 3 and continues to heat it, the molten salt comes out of the methyl sulfide synthesis reactor 2 and returns to the molten salt tank 3, the molten salt circulates and heats the methyl sulfide synthesis reactor 2 to 360°C;

[0060] S2, steam heater 1 heats the mixed gas of methanol and H2S, and the heated methanol and H2S enter the methyl sulfide synthesis reactor 2, ensuring that the methanol and H2S entering the methyl sulfide synthesis reactor 2 are evenly mixed to achieve the methyl sulfide synthesis reaction conditions, the methanol and H2S feed molar ratio is 2:1, the pressure is 0.2MPA, and the temperature is 360°C;

[0061] S3, driving the catalytic cylinder 200 to rotate and flipping the catalyst up and down at the same time, so as to ensure that the catalyst is heated evenly, avoid part of the catalyst from losing activity due to excessive heating, and make the catalyst contact with methanol and H2S more evenly, so as to promote the reaction of methanol and H2S to generate methyl sulfide, a small amount of methyl mercaptan and water;

[0062] S4, sending the cooled methyl sulfide to a methyl sulfide distillation tower 7, returning the light components methyl mercaptan and H2S at the top of the tower to the steam heater 1, and sending the methyl sulfide at the bottom of the tower to a methyl sulfide buffer tank 10;

[0063] S5, the hydrogen peroxide in the hydrogen peroxide buffer tank 9 is fed into the microreactor 14 by the hydrogen peroxide feed pump 11, and the methyl sulfide in the methyl sulfide buffer tank 10 is fed to the methyl sulfide preheater 13 by the methyl sulfide feed pump 12 to be preheated to 50° C., and then enters the microreactor 14 to react to generate crude dimethyl sulfoxide, and the unreacted hydrogen peroxide and methyl sulfide enter the multiphase reactor 15 along with the crude dimethyl sulfoxide to continue the reaction, and the feed molar ratio of hydrogen peroxide to methyl sulfide is controlled to be 2:1.05, the reaction temperature is 55-65° C., and the reaction pressure is 0.2 MPA, at which time the hydrogen peroxide conversion rate reaches 99%, and the methyl sulfide conversion rate reaches more than 95%;

[0064] S6, the crude dimethyl sulfoxide at the outlet of the multiphase reactor 15 enters the flash tank 16, and after flashing, the dimethyl sulfoxide is sent to the dimethyl sulfoxide crude stripping tower 21 through the crude dimethyl sulfoxide feed pump 17, and the light component methyl sulfide at the top of the tower flows into the crude stripping tower reflux tank 19 through the crude stripping tower condenser 18, and a part of the methyl sulfide is refluxed to the dimethyl sulfoxide crude stripping tower 21 through the crude stripping tower reflux pump 20, and the other part is sent to the methyl sulfide buffer tank 10 for recycling, and the dimethyl sulfoxide at the bottom of the dimethyl sulfoxide crude stripping tower 21 is sent to the dimethyl sulfoxide distillation equipment for further refining through the dimethyl sulfoxide distillation feed pump 22.

[0065] Embodiment 2:

[0066] The device for continuously preparing dimethyl sulfoxide in this embodiment is the same as that in the first embodiment, but the preparation method is different. Specifically, the preparation method for continuously preparing dimethyl sulfoxide comprises the following steps:

[0067] S1, nitrogen is pressurized by the nitrogen circulation fan 5 and enters the nitrogen electric heater 6, the heated nitrogen enters the methyl sulfide synthesis reactor 2, the nitrogen is discharged from the methyl sulfide synthesis reactor 2 and returns to the nitrogen circulation fan 5, the nitrogen circulates and heats the methyl sulfide synthesis reactor 2 to 200°C, the nitrogen heating is stopped, the molten salt pump 4 is started, the molten salt enters the methyl sulfide synthesis reactor 2 from the molten salt tank 3 and continues to heat it, the molten salt comes out of the methyl sulfide synthesis reactor 2 and returns to the molten salt tank 3, the molten salt circulates and heats the methyl sulfide synthesis reactor 2 to 380°C;

[0068] S2, steam heater 1 heats the mixed gas of methanol and H2S, and the heated methanol and H2S enter the methyl sulfide synthesis reactor 2 to ensure that the methanol and H2S entering the methyl sulfide synthesis reactor 2 are evenly mixed to achieve the methyl sulfide synthesis reaction conditions, the methanol and H2S feed molar ratio is 2.05:1, the pressure is 0.3MPA, and the temperature is 380°C;

[0069] S3, driving the catalytic cylinder 200 to rotate and flipping the catalyst up and down at the same time, so as to ensure that the catalyst is heated evenly, avoid part of the catalyst from losing activity due to excessive heating, and make the catalyst contact with methanol and H2S more evenly, so as to promote the reaction of methanol and H2S to generate methyl sulfide, a small amount of methyl mercaptan and water;

[0070] S4, sending the cooled methyl sulfide to a methyl sulfide distillation tower 7, returning the light components methyl mercaptan and H2S at the top of the tower to the steam heater 1, and sending the methyl sulfide at the bottom of the tower to a methyl sulfide buffer tank 10;

[0071] S5, the hydrogen peroxide in the hydrogen peroxide buffer tank 9 is fed into the microreactor 14 through the hydrogen peroxide feed pump 11, and the methyl sulfide in the methyl sulfide buffer tank 10 is fed to the methyl sulfide preheater 13 through the methyl sulfide feed pump 12 to be preheated to 60° C., and then enters the microreactor 14 to react to generate crude dimethyl sulfoxide, and the unreacted hydrogen peroxide and methyl sulfide enter the multiphase reactor 15 along with the crude dimethyl sulfoxide to continue the reaction, and the feed molar ratio of hydrogen peroxide to methyl sulfide is controlled to be 2:1.1, the reaction temperature is 60-70° C., and the reaction pressure is 0.3 MPA, at which time the hydrogen peroxide conversion rate reaches 100%, and the methyl sulfide conversion rate reaches more than 95%;

[0072] S6, the crude dimethyl sulfoxide at the outlet of the multiphase reactor 15 enters the flash tank 16, and after flashing, the dimethyl sulfoxide is sent to the dimethyl sulfoxide crude stripping tower 21 through the crude dimethyl sulfoxide feed pump 17, and the light component methyl sulfide at the top of the tower flows into the crude stripping tower reflux tank 19 through the crude stripping tower condenser 18, and a part of the methyl sulfide is refluxed to the dimethyl sulfoxide crude stripping tower 21 through the crude stripping tower reflux pump 20, and the other part is sent to the methyl sulfide buffer tank 10 for recycling, and the dimethyl sulfoxide at the bottom of the dimethyl sulfoxide crude stripping tower 21 is sent to the dimethyl sulfoxide distillation equipment for further refining through the dimethyl sulfoxide distillation feed pump 22.

[0073] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A device for continuously preparing dimethyl sulfoxide, comprising a methyl sulfide synthesis reactor, a methyl sulfide distillation tower, a methyl sulfide buffer tank, a microreactor, a multiphase reactor, a flash tank, a dimethyl sulfoxide crude stripping tower and a dimethyl sulfoxide distillation feed pump which are sequentially connected and arranged, characterized in that: The methyl sulfide synthesis reactor is provided with a nitrogen heating unit and a molten salt heating unit for heating the methyl sulfide synthesis reactor; A catalytic cylinder is arranged inside the methyl sulfide synthesis reactor, and can rotate and move relative to the methyl sulfide synthesis reactor. A catalytic chamber and a lifting chamber are arranged inside the catalytic cylinder. An upper opening and a lower opening are arranged between the catalytic chamber and the lifting chamber, respectively. A lifting mechanism is arranged in the lifting chamber, and is used to push the catalyst to move toward the upper opening when the catalytic cylinder rotates. The lifting mechanism includes a Jiaolong conveying shaft, which is rotatably installed inside the lifting chamber and can rotate with the movement of the catalytic cylinder. A baffle is installed between the catalytic chamber and the lifting chamber to slide up and down, and the size of the upper opening can be adjusted.

2. The device for continuously preparing dimethyl sulfoxide according to claim 1, characterized in that: The nitrogen heating unit includes a nitrogen circulation fan and a nitrogen electric heater, and the nitrogen circulation fan, the nitrogen electric heater and the dimethyl sulfide synthesis reactor are connected through a nitrogen circulation pipeline. The molten salt heating unit includes a molten salt tank and a molten salt pump, and the molten salt tank, the molten salt pump and the dimethyl sulfide synthesis reactor are connected through a molten salt circulation pipeline.

3. The device for continuously preparing dimethyl sulfoxide according to claim 2, characterized in that: The lifting mechanism also includes a transmission gear and a gear ring. The transmission gear is fixed to the end of the Jiaolong conveying shaft, and the gear ring is fixedly installed on the top wall of the methyl sulfide synthesis reactor, and the gear ring is meshed with the transmission gear.

4. The device for continuously preparing dimethyl sulfoxide according to claim 3, characterized in that: A driving mechanism is provided in the methyl sulfide synthesis reactor for driving the catalytic cartridge to rotate in the methyl sulfide synthesis reactor. The driving mechanism comprises a motor, a rotating shaft and a connecting rod. The rotating shaft is rotatably assembled in the methyl sulfide synthesis reactor. The motor is fixedly mounted on the top of the methyl sulfide synthesis reactor, and the output end of the motor is fixed to the end of the rotating shaft. The connecting rod is fixed on the rotating shaft, and the catalytic cartridge is fixedly mounted on the end of the connecting rod.

5. The device for continuously preparing dimethyl sulfoxide according to claim 4, characterized in that: The rotating shaft is provided with a push ring and a cylinder. The push ring is slidably assembled on the outside of the rotating shaft, the cylinder is fixedly installed on the outer wall of the rotating shaft, and the telescopic end of the cylinder is fixed on the push ring.

6. The device for continuously preparing dimethyl sulfoxide according to claim 4, characterized in that: A steam heater is provided on one side of the methyl sulfide synthesis reactor, which can heat the mixed gas of methanol and H2S, and the steam heater is connected to the methyl sulfide distillation tower.

7. The device for continuously preparing dimethyl sulfoxide according to claim 6, characterized in that: A methyl sulfide discharge pump is arranged between the methyl sulfide distillation tower and the methyl sulfide buffer tank, which is used to transport the methyl sulfide after distillation to the methyl sulfide buffer tank. A methyl sulfide feed pump and a methyl sulfide preheater are arranged between the methyl sulfide buffer tank and the microreactor, respectively. A hydrogen peroxide buffer tank is arranged on one side of the microreactor, and a hydrogen peroxide feed pump is arranged between the microreactor and the hydrogen peroxide buffer tank.

8. The device for continuously preparing dimethyl sulfoxide according to claim 7, characterized in that: A crude dimethyl sulfoxide feed pump is arranged between the flash tank and the dimethyl sulfoxide crude stripping tower, a crude stripping tower reflux tank is arranged on the top of the dimethyl sulfoxide crude stripping tower, a crude stripping tower condenser is arranged between the crude stripping tower reflux tank and the dimethyl sulfoxide crude stripping tower, a crude stripping tower reflux pump is arranged outside the crude stripping tower reflux tank, and one end of the crude stripping tower reflux pump away from the crude stripping tower reflux tank is respectively connected to the dimethyl sulfoxide crude stripping tower and the methyl sulfide buffer tank.

9. The device for continuously preparing dimethyl sulfoxide according to claim 8, characterized in that: A dimethyl sulfoxide distillation feed pump is arranged at the bottom of the dimethyl sulfoxide crude removal tower, and an output end of the dimethyl sulfoxide distillation feed pump is connected to a dimethyl sulfoxide distillation device.

10. A method for continuously preparing dimethyl sulfoxide, characterized in that: The device for continuously preparing dimethyl sulfoxide according to claim 9 comprises the following steps: S1. Nitrogen is pressurized by a nitrogen circulation fan and then enters a nitrogen electric heater for heating. After the nitrogen circulates and heats the methyl sulfide synthesis reactor to 180°C, the nitrogen heating is stopped, and then the molten salt pump is started. The molten salt enters the methyl sulfide synthesis reactor from the molten salt tank and continues to be heated. The methyl sulfide synthesis reactor is circulated and heated to 360°C. S2, the steam heater heats the mixed gas of methanol and H2S, and the heated methanol and H2S enter the dimethyl sulfide synthesis reactor, the feed molar ratio of methanol to H2S is 2:1, the pressure is 0.2MPA, and the temperature is 360°C; S3, driving the catalytic cylinder to rotate and flipping the catalyst up and down at the same time, so that the catalyst is evenly contacted with methanol and H2S, and methanol and H2S react to generate methyl sulfide, a small amount of methyl mercaptan and water; S4, sending the cooled methyl sulfide to a methyl sulfide distillation tower, returning the light components methyl mercaptan and H2S at the top of the tower to the steam heater, and sending the methyl sulfide at the bottom of the tower to a methyl sulfide buffer tank; S5, the hydrogen peroxide in the hydrogen peroxide buffer tank is fed into the microreactor by a hydrogen peroxide feed pump, the methyl sulfide in the methyl sulfide buffer tank is fed to the methyl sulfide preheater by a methyl sulfide feed pump, preheated to 50°C, and then enters the microreactor for reaction to generate crude dimethyl sulfoxide, and the unreacted hydrogen peroxide and methyl sulfide enter the multiphase reactor along with the crude dimethyl sulfoxide to continue the reaction, and the feed molar ratio of hydrogen peroxide to methyl sulfide is controlled to be 2:1.05, the reaction temperature is 55-65°C, and the reaction pressure is 0.2MPA, so that the hydrogen peroxide conversion rate reaches 99%, and the methyl sulfide conversion rate reaches more than 95%; S6. The crude dimethyl sulfoxide at the outlet of the multiphase reactor enters a flash tank. After flash evaporation, the dimethyl sulfoxide is sent to a dimethyl sulfoxide crude stripping tower. The light component methyl sulfide at the top of the tower flows into the reflux tank of the crude stripping tower through the crude stripping tower condenser. A part of the methyl sulfide in the reflux tank of the crude stripping tower is refluxed to the dimethyl sulfoxide crude stripping tower by a crude stripping tower reflux pump, and the other part is sent to a methyl sulfide buffer tank for recycling. The dimethyl sulfoxide at the bottom of the dimethyl sulfoxide crude stripping tower is sent to the dimethyl sulfoxide distillation equipment for further refining by a dimethyl sulfoxide distillation feed pump.

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