Reaction device and synthesis process for continuously producing dimethyl sulfoxide

Abstract

The invention discloses a reaction device for continuously producing dimethyl sulfoxide and a synthesis process, the reaction device comprises a rack, a reactor assembly, a heat exchange assembly, a pipeline assembly and a control assembly, the pipeline assembly comprises a feeding pipe and a discharging pipe, the feeding pipe and the discharging pipe are both communicated with the reactor assembly, and the heat exchange assembly is arranged on the rack; a material temperature transmitter and a first pressure transmitter are arranged on each of the feeding pipe and the discharging pipe; the heat exchange assembly comprises a heat exchange shell and a circulating cooling device, the reactor assembly is located in the heat exchange shell, the circulating cooling device is communicated with the first heat exchange space, and the heat exchange shell is provided with a first temperature transmitter; the reactor assembly comprises a reactor shell and a micro-reactor, the micro-reactor is arranged in the reactor shell, the circulating cooling device is communicated with the second heat exchange space, and the first temperature transmitter detects the temperature in the micro-reactor. According to the method, the existing dimethyl sulfoxide production process is simplified, the production cost is reduced, the product purity is high, byproducts are few, waste water and waste gas are less, and the requirement of green chemical development is met.

Description

Technical Field

[0001] The present invention belongs to the technical field of fine chemical engineering, and particularly relates to a reaction device and a synthesis process for continuously producing dimethyl sulfoxide. Background Art

[0002] Dimethyl sulfoxide (DMSO) is a sulfur-containing organic compound with the molecular formula C2H6OS. It is a colorless, odorless, and transparent liquid at room temperature, with characteristics such as high polarity, high boiling point, and good thermal stability. It can dissolve in most organic substances such as ethanol, propanol, benzene, and chloroform. It is a very important organic solvent and pharmaceutical intermediate, and is therefore also known as the "universal" solvent. With the rapid development of related fields such as fine chemical engineering and pharmaceuticals, the market demand for DMSO is increasing continuously, showing a strong development momentum, and the market scale is expected to exceed 10 billion. At the same time, higher requirements are also put forward for its preparation efficiency, process safety, environmental protection, and quality.

[0003] In the industrial production of dimethyl sulfoxide, the traditional process mainly uses dimethyl sulfide (DMS) to prepare through an oxidation reaction, and common oxidants include nitric acid, oxygen, or ozone, etc. However, the existing technology generally has the problem that it is difficult to realize continuous production in the production process. The production equipment of the existing process cannot meet the requirements of continuous production, and there are also problems such as high energy consumption, high operating cost, and low mass transfer and heat transfer efficiency. On the other hand, there are also problems such as high safety risks in the production process and unstable product performance, which seriously do not conform to the concept of green and safe chemistry advocated now, and severely restrict the large-scale industrial production of dimethyl sulfoxide. If a more efficient and process-safe and environmentally friendly dimethyl sulfoxide device and synthesis process can be developed on the basis of the existing process, it has very important economic significance. Summary of the Invention

[0004] In order to solve the above technical problems, the purpose of the present invention is to provide a reaction device and a synthesis process for continuously producing dimethyl sulfoxide, which simplifies the existing dimethyl sulfoxide production process, reduces production costs, and has high product purity, few by-products, and less waste water and waste gas, meeting the requirements of the development of green chemistry.

[0005] In order to achieve the above invention purpose, the technical solutions adopted by the present invention are as follows:

[0006] In the first aspect of the present invention, the present invention proposes a reaction device for continuously producing dimethyl sulfoxide, including a frame and a reactor assembly, a heat exchange assembly, a pipeline assembly, and a control assembly arranged on the frame. The control assembly is connected to the reactor assembly, the heat exchange assembly, and the pipeline assembly, wherein;

[0007] The pipeline assembly includes a feed pipe and a discharge pipe. The feed pipe is connected to the feed port of the reactor assembly, and the discharge pipe is connected to the discharge port of the reactor assembly. Among them, material temperature transmitters and first pressure transmitters are provided on both the feed pipe and the discharge pipe.

[0008] The heat exchange assembly includes a heat exchange housing and a circulating cooling device. The reactor assembly is located inside the heat exchange housing. There is a first heat exchange space between the reactor assembly and the heat exchange housing. The circulating cooling device is connected to the first heat exchange space. The heat exchange housing is also provided with a first temperature transmitter, and the first temperature transmitter is connected to the reactor assembly.

[0009] The reactor assembly includes a reactor housing and a microreactor. The microreactor is arranged inside the reactor housing. The microreactor is integrally formed by 3D printing or the microreactor and the reactor housing are integrally formed by 3D printing. There is a second heat exchange space between the microreactor and the reactor housing. The circulating cooling device is connected to the second heat exchange space. The first temperature transmitter detects the internal temperature of the microreactor.

[0010] Preferably, the number of reactor assemblies is greater than or equal to one. Two or more reactor assemblies are arranged in series. The first reactor assembly is connected to the feed pipe, and the last reactor assembly is connected to the discharge pipe. A temperature transmitter is provided for each reactor assembly, and each reactor assembly is connected to the circulating cooling device.

[0011] More preferably, adjacent reactor assemblies are connected through an auxiliary pipe. A second temperature transmitter and a second pressure transmitter are provided on the auxiliary pipe. A three-way check valve is provided on the auxiliary pipe.

[0012] Preferably, the microreactor includes multiple layers of microchannel groups connected in series front and back. The microchannel group includes one or more channel units, and multiple channel units are connected in series.

[0013] The channel unit includes a Y-shaped upper pipe, an upper annular pipe, a transition pipe, a lower annular pipe, a Y-shaped lower pipe, and a connecting pipe. Multiple transition pipes are arranged horizontally in the middle of the channel unit. Multiple upper annular pipes are arranged above the transition pipe. The upper annular pipe is connected to the transition pipe through a connecting pipe. The Y-shaped upper pipe is arranged upside down above the upper annular pipe. The bottom branch pipe of the Y-shaped upper pipe is connected to the upper annular pipe through a connecting pipe. Multiple lower annular pipes are arranged below the transition pipe. The lower annular pipe is connected to the transition pipe through a connecting pipe. The Y-shaped lower pipe is arranged below the lower annular pipe. The top branch pipe of the Y-shaped lower pipe is connected to the lower annular pipe through a connecting pipe.

[0014] The first channel unit in one layer of the microchannel group is used as the feed end, and the last channel unit is the discharge end. The feed end of the first layer of the microchannel group is used as the material feed end, and the discharge end of the last layer of the microchannel group is used as the material discharge end. Among adjacent two layers of microchannel groups, the discharge end of the microchannel group in the front position is connected to the feed end of the microchannel group in the rear position through a connecting pipe.

[0015] Preferably, in one channel unit, the number of upper annular tubes is n, where n ≥ 2 and n is an even number. One bottom branch of the Y-shaped upper tube is connected to n / 2 adjacent upper annular tubes, and the other bottom branch of the Y-shaped upper tube is connected to the remaining n / 2 adjacent upper annular tubes;

[0016] The number of lower annular tubes is also n, where n ≥ 2 and n is an even number. One top branch of the Y-shaped lower tube is connected to n / 2 adjacent lower annular tubes, and the other top branch of the Y-shaped lower tube is connected to the remaining n / 2 adjacent lower annular tubes.

[0017] More preferably, in one channel unit, the number of transition tubes is n - 1. Each transition tube is respectively connected to two adjacent upper annular tubes through two connecting tubes, and each transition tube is respectively connected to two adjacent lower annular tubes through two connecting tubes.

[0018] Preferably, a three-way check valve is provided at the connection between the feed pipe and the reactor assembly, and a three-way check valve is provided at the connection between the discharge pipe and the reactor assembly.

[0019] In the second aspect of the present invention, the present invention proposes a synthetic process for continuously producing dimethyl sulfoxide as follows:

[0020] Dimethyl sulfide and an oxidant are respectively introduced into the reactor assembly through the feed pipe. The delivery amounts of dimethyl sulfide and the oxidant are monitored by the first pressure transmitter, and the oxidant is in excess to ensure that dimethyl sulfide is converted into dimethyl sulfoxide as much as possible. The product is output through the discharge pipe, and the output amount of the product is monitored by the first pressure transmitter;

[0021] Set the temperature and start the circulating cooling device. Monitor the temperature of the material in the microreactor through the first temperature transmitter, detect the temperature of the raw material feed and the product discharge through the material temperature transmitter, and cooperate with the circulating cooling device to make the microreactor of the reactor assembly within the set temperature range.

[0022] Preferably, the oxidant is hydrogen peroxide with a mass concentration of 27.5 - 35%, the purity of dimethyl sulfide ≥ 99%, and the molar ratio of dimethyl sulfide to hydrogen peroxide is 1:(1.01 - 1.50). More preferably, the molar ratio of dimethyl sulfide to hydrogen peroxide is 1:(1.05 - 1.50).

[0023] More preferably, dimethyl sulfide and hydrogen peroxide are respectively introduced into the reactor assembly, the set temperature is 55 - 80 °C, and the circulating cooling device is started to make the microreactor of the reactor assembly within the set temperature range.

[0024] Beneficial effects:

[0025] Compared with traditional kettle reactors and plate reactors, the reaction device designed in the present invention is based on the basic characteristics of the thioether oxidation reaction. Under the condition of ensuring the strong mixing and mass transfer effects of the microchannel structure, the heat exchange capacity of the reaction is greatly improved, which can ensure that nearly 80% of the reaction is completed within dozens of seconds in the microchannel, and ensure that the heat generated by the reaction can be quickly transferred out in a short time. It is worth mentioning that this reactor can achieve a production capacity of more than 6000 tons of dimethyl sulfoxide per year. The present invention simplifies the existing dimethyl sulfoxide production process, reduces production costs, and the product has high purity, few by-products, and less waste water and waste gas, meeting the requirements of the development of green chemistry. Brief Description of the Drawings

[0026] Figure 1 The following shows the overall schematic diagram of the present invention;

[0027] Figure 2 The following shows the process flow diagram of the present invention, where T represents a temperature transmitter and P represents a pressure transmitter;

[0028] Figure 3 The following shows the schematic diagram of the reactor housing of the present invention, which has a feed inlet, a discharge outlet, and a temperature measurement port;

[0029] Figure 4 The following shows the schematic diagram of the preferred microreactor of the present invention;

[0030] Figure 5 The following is Figure 4 the front schematic diagram of, where the cross-sectional schematic diagram of the first layer of microchannel groups is shown.

[0031] Reference Numerals: 1 - Frame;

[0032] 2 - Reactor Assembly, 21 - Reactor Housing, 22 - Microreactor, 221 - Microchannel Group, 2211 - Y-shaped Upper Tube, 2212 - Upper Annular Tube, 2213 - Transition Tube, 2214 - Lower Annular Tube, 2215 - Y-shaped Lower Tube, 2216 - Connecting Tube;

[0033] 3 - Heat Exchange Assembly, 31 - Heat Exchange Housing, 32 - First Temperature Transmitter, 33 - First Refrigerant Inlet, 34 - First Refrigerant Outlet, 35 - Second Refrigerant Inlet, 36 - Second Refrigerant Outlet, 37 - Drainage Port;

[0034] 4 - Pipeline Assembly, 41 - Feed Pipe, 42 - Discharge Pipe, 43 - Material Temperature Transmitter, 44 - First Pressure Transmitter, 45 - Sampling Port;

[0035] 5 - Control Assembly;

[0036] 6 - Three-way Check Valve. Detailed Embodiments

[0037] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the specific embodiments of the present invention will be described below with reference to the accompanying drawings. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings, and other embodiments can also be obtained.

[0038] During the oxidation of dimethyl sulfide to produce dimethyl sulfoxide, it is easy to over-oxidize to produce by-product dimethyl sulfone. Therefore, the reaction temperature needs to be precisely controlled. Taking the reaction of dimethyl sulfide with hydrogen peroxide as an example, the main reaction is: (CH3)2S + H2O2 →

[0039] (CH3)2SO + H2O + 66.52 kcal. The products are dimethyl sulfoxide and water. Except for the product, the other products are harmless, meeting the requirements of green chemistry. However, this reaction is an exothermic reaction, releasing a large amount of heat. If the temperature gets out of control, it may cause violent boiling or side reactions. The reaction temperature needs to be strictly controlled. Otherwise, too high a temperature will cause dimethyl sulfide to be further oxidized to dimethyl sulfone. Moreover, at a relatively high temperature, hydrogen peroxide is also prone to decomposition, reducing the oxidation efficiency and possibly causing safety hazards. If the method of slowly adding hydrogen peroxide or directly cooling is adopted, the efficiency of this reaction is low and continuous production cannot be achieved. The present invention proposes a reaction device for continuously producing dimethyl sulfoxide to achieve precise temperature control, optimize its synthesis process route, and meet the production capacity requirements of more than a thousand tons.

[0040] As Figures 1-5 shown, the reaction device for continuously producing dimethyl sulfoxide includes a frame 1 and a reactor assembly 2, a heat exchange assembly 3, a pipeline assembly 4, and a control assembly 5 provided on the frame 1. The reactor assembly 2 is located inside the heat exchange assembly 3. The pipeline assembly 4 is connected to the reactor assembly 2. The control assembly 5 is respectively connected to the heat exchange assembly 3 and the pipeline assembly 4 for controlling the temperature and controlling the material transportation. The technical solutions of the present invention will be introduced in detail below with specific structures:

[0041] The pipeline assembly 4 is installed on the frame 1, including a feed pipe 41 and a discharge pipe 42. The number of feed pipes 41 is greater than or equal to one. The feed pipe 41 is connected to the feed port of the reactor assembly 2, and the discharge pipe 42 is connected to the discharge port of the reactor assembly 2. Among them, a material temperature transmitter 43 and a first pressure transmitter 44 are provided on each feed pipe 41, and a material temperature transmitter 43 and a first pressure transmitter 44 are also provided on the discharge pipe 42. The first pressure transmitter 44 detects the flow rate of the material in the pipeline. The control assembly 5 controls the inflow and outflow of the material. By controlling the flow rate of the feed, the ratio of dimethyl sulfide to the oxidant can be controlled, and the utilization rate of the raw materials can be improved as much as possible. The temperature transmitter detects the temperature of the feed and the discharge. The material temperature transmitter 43 and the first pressure transmitter 44 are both connected to the control assembly 5.

[0042] Preferably, since dimethyl sulfide reacts easily when in contact with the oxidant, dimethyl sulfide and the oxidant are respectively introduced into the reactor assembly 2 and then mixed for reaction. The number of feed pipes 41 is greater than or equal to two. One of the feed pipes 41 is a dimethyl sulfide feed pipe 41, and the remaining feed pipes 41 are feed pipes 41 for the oxidant and other related materials. When the oxidant is hydrogen peroxide, the number of feed pipes 41 is two. One feed pipe 41 is a dimethyl sulfide feed pipe 41, and the other feed pipe 41 is a hydrogen peroxide feed pipe 41.

[0043] The number of discharge pipes 42 for the product is greater than or equal to one. The product is output from the reactor assembly 2 and can be output in the form of a single stream of material or divided into multiple streams of material.

[0044] Further, a three-way check valve is provided at the connection between the feed pipe 41 and the reactor assembly 2, and a three-way check valve is provided at the connection between the discharge pipe 42 and the reactor assembly 2. The three-way check valve prevents the material from flowing back. In addition, the three-way check valve is connected to the waste liquid pipe, playing a role in pressure relief and liquid discharge.

[0045] Further, a sampling port 45 is also provided on the discharge pipe 42, and a valve is provided at the sampling port 45 for detecting the product.

[0046] As Figure 1 shown, a valve is provided at the feed end of the feed pipe 41, and a valve is also provided at the discharge end of the discharge pipe 42. These two valves can be manual valves, such as ball valves and butterfly valves, or solenoid valves, and are connected to the control assembly 5 to achieve automatic control.

[0047] The heat exchange assembly 3 includes a heat exchange housing 31 and a circulating cooling device. The heat exchange housing 31 is shown in the figure, and the circulating cooling device is not shown. The reactor assembly 2 is located inside the heat exchange housing 31. There is a first heat exchange space between the reactor assembly 2 and the heat exchange housing 31. The circulating cooling device delivers refrigerant into the first heat exchange space to keep the temperature of the reactor assembly 2 within a suitable range. As Figure 1As shown, a first refrigerant inlet 33 and a first refrigerant outlet 34 are provided on the heat exchange housing 31. The circulating cooling device is connected to the first refrigerant inlet 33 and the first refrigerant outlet 34 to convey refrigerant to the heat exchange space. The feed pipe 41 and the discharge pipe 42 both pass through the heat exchange housing 31 and are connected to the reactor assembly 2. The heat exchange housing 31 is also provided with a first temperature transmitter 32, and the first temperature transmitter 32 is connected to the reactor assembly 2 to detect whether the material temperature in the reactor assembly 2 is within the optimal range.

[0048] It is easy to understand that valves, electronic devices, etc. on the feed pipe 41 and the discharge pipe 42 are all outside the heat exchange housing 31. The reactor assembly 2 is in a sealed state inside the heat exchange housing 31. An opening is provided on the heat exchange housing 31, and the opening is respectively communicated with corresponding feed ports, discharge ports, etc. of the reactor assembly 2. The feed pipe 41 and the discharge pipe 42 are connected at corresponding positions on the heat exchange housing 31.

[0049] The first temperature transmitter 32, the second temperature transmitter and the circulating cooling device are all connected to the control assembly 5. In the present invention, the circulating cooling device is an existing conventional cooling device. Preferably, water is used as the refrigerant in the present invention. Through the cooperation of the temperature transmitter and the circulating cooling device, the temperature of the reactor assembly 2 is precisely regulated.

[0050] The reactor assembly 2 includes a reactor outer shell 21 and a microreactor 22. The microreactor 22 is inside the reactor outer shell 21. Preferably, the microreactor 22 is integrally formed by 3D printing or the microreactor 22 and the reactor outer shell 21 are integrally formed by 3D printing. There is a second heat exchange space between the microreactor 22 and the reactor outer shell 21. The reactor outer shell 21 is provided with a heat exchange inlet and a heat exchange outlet. The heat exchange housing is provided with a second refrigerant inlet 35 and a second refrigerant outlet 36. The heat exchange inlet is communicated with the second refrigerant inlet 35, and the heat exchange outlet is connected to the second cooling outlet. The circulating cooling device is connected to the second refrigerant inlet 35 and the second refrigerant outlet 36.

[0051] As Figures 3-5 shown, the reactor outer shell 21 is also provided with structures such as a feed port and a discharge port, which are respectively communicated with the feed port and the discharge port of the microreactor 22. The feed port and the discharge port of the reactor outer shell 21 are also respectively communicated with corresponding openings of the heat exchange housing. A temperature measuring port is also provided on the reactor outer shell 21 for installing the second temperature transmitter, and the second temperature transmitter detects the material temperature in the microreactor 22. It is easy to understand that the microreactor 22 is also in a sealed state inside the reactor outer shell 21, that is, the heat exchange spaces between the first heat exchange space and the second outer shell are not communicated.

[0052] In the present invention, the number of reactor assemblies 2 is greater than or equal to one. When the number of reactor assemblies 2 is two or more, the multiple reactor assemblies 2 are arranged in series. The first reactor assembly 2 is communicated with the feed pipe 41, and the last reactor assembly 2 is communicated with the discharge pipe 42. A temperature transmitter is provided for each reactor assembly 2, and each reactor assembly 2 is communicated with a circulating cooling device. Figures 3-5 The shown reactor assembly 2 is the first reactor assembly 2. The feed port needs to receive dimethyl sulfide and an oxidant simultaneously, and the refrigerant inlet and outlet are not shown.

[0053] As Figure 1 and 2 shown, taking two reactor assemblies 2 as an example, two sets of second refrigerant inlets 35 and second refrigerant outlets 36 are provided on the heat exchange housing 31. That is, each reactor assembly 2 is independently temperature-controlled, and each reactor assembly 2 also corresponds to an independent first temperature transmitter 32 for independently monitoring the temperature change of the micro-reactor 22.

[0054] Furthermore, adjacent reactor assemblies 2 are communicated through an auxiliary pipe. A second temperature transmitter and a second pressure transmitter are provided on the auxiliary pipe for detecting the material flow rate and the material temperature. The second temperature transmitter and the second pressure transmitter are both communicated with the control assembly 5. It is easy to understand that the second temperature transmitter and the second pressure transmitter are both outside the heat exchange housing.

[0055] A three-way check valve 6 is also provided on the communicating pipe, which can relieve the pressure of the waste liquid from the auxiliary pipe and discharge it. A drain port 37 is provided on the bottom surface of the heat exchange housing and is communicated with the three-way check valve 6 of the auxiliary pipe. For example, in the early stage of production, when the reaction is not yet stable after passing through the previous reactor assembly 2, the waste liquid can be discharged through the three-way check valve 6 of the auxiliary pipe, or when other equipment failures occur, the waste liquid can be discharged in time through the three-way check valve 6 of the auxiliary pipe.

[0056] Furthermore, valves such as manual valves and electric valves are also provided on the auxiliary pipe.

[0057] The micro-reactor 22 includes a series of multiple micro-channel groups 221. The feed port of the first layer of micro-channel group 221 serves as the material feed port of the micro-reactor 22, and the discharge port of the last layer of micro-channel group 221 serves as the material discharge port of the micro-reactor 22. The multiple micro-channel groups 221 are in full contact with the refrigerant in the reactor housing 21, quickly transferring the heat generated by the reaction to ensure that the temperature in the micro-channel group 221 is within the optimal range. Preferably, the inner diameter range of the pipes in the micro-channel group 221 is 3-16 mm.

[0058] Based on the above reaction device, the present invention also proposes a synthesis process for continuously producing dimethyl sulfoxide as follows:

[0059] Dimethyl sulfide and an oxidant are respectively introduced into the reactor assembly 2 through the feed pipes 41. The delivery amounts of dimethyl sulfide and the oxidant are monitored by the first pressure transmitter 44, and the oxidant is in excess to ensure that dimethyl sulfide is converted into dimethyl sulfoxide as much as possible. The product is output through the discharge pipe 42, and the output amount of the product is monitored by the first pressure transmitter 44;

[0060] Set the temperature and start the circulating cooling device. The temperature of the material in the microreactor 22 is monitored by the first temperature transmitter 32, and the temperatures of the raw material feed and the product discharge are detected by the material temperature transmitter 43. In cooperation with the circulating cooling device, the microreactor 22 of the reactor assembly 2 is maintained within the set temperature range.

[0061] Preferably, the oxidant is hydrogen peroxide with a mass concentration of 27.5 - 35%, the purity of dimethyl sulfide is ≥99%, and the molar ratio of dimethyl sulfide to hydrogen peroxide is 1:(1.01 - 1.50). More preferably, the molar ratio of dimethyl sulfide to hydrogen peroxide is 1:(1.05 - 1.50);

[0062] Dimethyl sulfide and hydrogen peroxide are respectively introduced into the reactor assembly 2. The set temperature is 55 - 80°C, and the circulating cooling device is started to keep the microreactor 22 of the reactor assembly 2 within the set temperature range.

[0063] Dimethyl sulfide and hydrogen peroxide can complete 60% of the reaction within 6 - 15 seconds in the microreactor 22, and the reaction with rock is completely reacted in the subsequent microreactor 22. The reactor assembly 2 outputs a high-purity dimethyl sulfoxide product.

[0064] During the whole reaction process, there are multiple temperature and pressure monitoring points to monitor the changes of temperature and pressure in real time during the reaction to ensure the quality and stability of the product.

[0065] Taking the preparation of dimethyl sulfoxide by reacting dimethyl sulfide and hydrogen peroxide using two reactor assemblies as an example, the effects of the present invention are illustrated by the following specific examples:

[0066] Example 1

[0067] The molar ratio of dimethyl sulfide to hydrogen peroxide is 1:1.03. During the reaction process, the temperatures in the two reactor assemblies are detected to be 60.3°C and 63.8°C respectively. In the output material, the mass percentage of water is 64.89%, and the mass percentage of dimethyl sulfoxide (the target product) is 34.95%.

[0068] Example 2

[0069] The molar ratio of dimethyl sulfide to hydrogen peroxide is 1:1.03. During the reaction process, the temperatures in two reactor components are detected to be 63.8 °C and 57.2 °C respectively. In the output material, the mass percentage of water is 65.25%, and the mass percentage of dimethyl sulfoxide (the target product) is 34.52%.

[0070] Example 3

[0071] The molar ratio of dimethyl sulfide to hydrogen peroxide is 1:1.01. During the reaction process, the temperatures in two reactor components are detected to be 54.2 °C and 58.8 °C respectively. In the output material, the mass percentage of water is 64.62%, and the mass percentage of dimethyl sulfoxide (the target product) is 35.09%.

[0072] Based on the examples, it can be seen that the present invention can improve the yield of dimethyl sulfoxide, effectively avoid excessive generation of by-products such as dimethyl sulfone, the main by-product is water, and the overall process is green and environmentally friendly.

[0073] The present invention does not limit the structure of the microchannel group 221. Figures 4-5 The most preferred structure of the microchannel group 221 of the present invention is shown as follows:

[0074] The microchannel group 221 includes one or more channel units. The multiple channel units are arranged in parallel and in series. The channel unit includes a Y-shaped upper tube 2211, an upper annular tube 2212, a transition tube 2213, a lower annular tube 2214, a Y-shaped lower tube 2215 and a connecting tube 2216. A plurality of transition tubes 2213 are arranged horizontally in the middle of the channel unit. A plurality of upper annular tubes 2212 are arranged above the transition tubes 2213. The upper annular tube 2212 is communicated with the transition tube 2213 through the connecting tube 2216. The Y-shaped upper tube 2211 is inverted and arranged above the upper annular tube 2212. The bottom branch of the Y-shaped upper tube 2211 is communicated with the upper annular tube 2212 through the connecting tube 2216. A plurality of lower annular tubes 2214 are arranged below the transition tubes 2213. The lower annular tube 2214 is communicated with the transition tube 2213 through the connecting tube 2216. The Y-shaped lower tube 2215 is arranged below the lower annular tube 2214. The top branch of the Y-shaped lower tube 2215 is communicated with the lower annular tube 2214 through the connecting tube 2216;

[0075] The first channel unit in one layer of the microchannel group 221 serves as the feed end, and the last channel unit is the discharge end. The feed end of the first layer of the microchannel group 221 serves as the raw material feed end, and the discharge end of the last layer of the microchannel group 221 serves as the product discharge end. In adjacent two layers of the microchannel group 221, the discharge end of the microchannel group 221 in the front position is communicated with the feed end of the microchannel group 221 in the rear position.

[0076] The micro-reactor 22 of the present invention can be integrally formed by 3D printing using a corrosion-resistant alloy material, such as corrosion-resistant 316L stainless steel.

[0077] In the channel unit, with the position of the transition pipe 2213 as the center, the Y-shaped upper pipe 2211, the upper annular pipe 2212, and the connecting pipe 2216 therebetween form a tree-like structure. Similarly, the lower annular pipe 2214, the Y-shaped lower pipe 2215, and the connecting pipe 2216 therebetween also form a tree-like structure. Preferably, as Figures 4-5 shown, with the position of the transition pipe 2213 as the center, the inside has an up-and-down symmetric structure.

[0078] The Y-shaped upper pipe 2211 is in an inverted state. The number of top branches of the Y-shaped upper pipe 2211 is one, and the number of bottom branches of the Y-shaped upper pipe 2211 is two. The Y-shaped lower pipe 2215 is in a normal state. The number of top branches of the Y-shaped lower pipe 2215 is two, and the number of bottom branches of the Y-shaped lower pipe 2215 is one. It is easy to understand that for one channel unit, one of the Y-shaped upper pipe 2211 and the Y-shaped lower pipe 2215 is for feeding, and the other is for discharging.

[0079] Both the upper annular pipe 2212 and the lower annular pipe 2214 refer to pipes whose internal pipelines are annular. The shape of the transition pipe 2213 is not limited. It plays a role in partially converging the materials, and then the materials flow out from the transition pipe 2213 and are then split by the lower annular pipe 2214. In the present invention, the multiple transition pipes 2213 are not directly connected to each other, the multiple upper annular pipes 2212 are not directly connected to each other, and similarly, the multiple lower annular pipes 2214 are not directly connected to each other.

[0080] Combined with Figures 4-5 it can be seen that the first channel unit in one layer of the microchannel group 221 serves as the feeding end, the last channel unit serves as the discharging end, the feeding end of the first layer of the microchannel group 221 serves as the raw material feeding end, the discharging end of the last layer of the microchannel group 221 serves as the product discharging end. In adjacent two layers of the microchannel group 221, the discharging end of the microchannel group 221 in the front position is connected to the feeding end of the microchannel group 221 in the rear position through the connecting pipe 2216.

[0081] When only one channel unit is included in one layer of the microchannel group 221, the top branches of the Y-shaped upper pipe 2211 in adjacent two layers of the microchannel group 221 are connected through the connecting pipe 2216 or the bottom branches of the Y-shaped lower pipe 2215 are connected through the connecting pipe 2216. The Y-shaped upper pipe 2211 or the Y-shaped lower pipe 2215 of the channel unit in the first layer of the microchannel group 221 serves as the raw material feeding end, and the Y-shaped upper pipe 2211 or the Y-shaped lower pipe 2215 of the channel unit in the last layer of the microchannel group 221 serves as the product discharging end.

[0082] When there are two or more channel units in a layer of microchannel group 221, the multiple channel units are arranged side by side, and the Y-shaped upper tubes 2211 of adjacent channel units are connected through connecting tubes 2216 or the Y-shaped lower tubes 2215 are connected through connecting tubes 2216. That is, after the material enters a layer of microchannels, it will flow through all channel units.

[0083] Figures 4-5 Taking the case where there are two channel units in a layer of microchannel group 22111 as an example, the top branch of the Y-shaped upper tube 2211 of the first channel unit is used as the feed end, and the bottom branch of the Y-shaped lower tube 2215 is the discharge end. The bottom branch of the Y-shaped lower tube 2215 of the second channel unit is the feed end, and the Y-shaped upper tube 2211 is the discharge end. The Y-shaped upper tube 2211 of the first channel unit of the adjacent microchannel group 221 behind is connected to the Y-shaped upper tube 2211 of the second channel unit of the previous microchannel group 221, thereby realizing the series connection of multiple layers of microchannel groups 221.

[0084] Taking a layer of microchannel group 221 as an example, the material flows into the first channel unit from top to bottom. First, it is split into two streams along the Y-shaped upper tube 2211. The two streams of material flow into multiple upper annular tubes 2212 respectively, and then converge for the first time in multiple transition tubes 2213. Then they flow into multiple lower annular tubes 2214 respectively, and finally converge into the Y-shaped lower tube 2215 and flow into the second channel unit and flow from bottom to top. The material converges at the Y-shaped upper tube 2211 of the second channel unit and flows into the next layer of microchannel group 221.

[0085] In the present invention, the upper annular tubes 2212, the lower annular tubes 2214, the transition tubes 2213, and the connecting tubes 2216 between them play a role in increasing the contact area between the microchannel group 221 and the refrigerant. Moreover, during the transportation process of the material, it experiences multiple splits - partial convergences - re-splits - convergences, which is conducive to the full mixing and contact between the raw materials and accelerates the progress of the reaction. Since the material is dispersed in each small area of the channel unit, the heat released by it is quickly taken away, and the temperature of the corresponding area is within a suitable range, effectively reducing the occurrence of side reactions and the generation of by-products.

[0086] Preferably, in a channel unit, the number of upper annular tubes 2212 is n, where n≥2 and n is an even number. One bottom branch of the Y-shaped upper tube 2211 is connected to n / 2 adjacent upper annular tubes 2212, and the other bottom branch of the Y-shaped upper tube 2211 is connected to the remaining n / 2 adjacent upper annular tubes 2212. That is, the Y-shaped upper tube 2211 and the upper annular tubes 2212 form a tree-like structure, and the material forms multiple non-converging streams after passing through the Y-shaped upper tube 2211 and the upper annular tubes 2212.

[0087] The number of the lower annular pipes 2214 is also n, where n≥2 and n is an even number. One of the top branches of the Y-shaped lower pipe 2215 is communicated with n / 2 adjacent lower annular pipes 2214, and the other top branch of the Y-shaped lower pipe 2215 is communicated with the remaining n / 2 adjacent lower annular pipes 2214. That is, the Y-shaped lower pipe 2215 and the lower annular pipes 2214 form an inverted tree-like structure, and multiple streams of materials converge into one stream of material at the bottom branch pipe of the Y-shaped lower pipe 2215.

[0088] As Figures 4-5 shown, n is preferably 4. That is, one of the bottom branches of the Y-shaped upper pipe 2211 is communicated with 2 adjacent upper annular pipes 2212, and the other bottom branch of the Y-shaped upper pipe 2211 is communicated with the remaining 2 adjacent upper annular pipes 2212. One of the top branches of the Y-shaped lower pipe 2215 is communicated with 2 adjacent lower annular pipes 2214, and the other top branch of the Y-shaped lower pipe 2215 is communicated with the remaining 2 adjacent lower annular pipes 2214.

[0089] Preferably, in one channel unit, the number of the transition pipes 2213 is n - 1. Each transition pipe 2213 is respectively communicated with two adjacent upper annular pipes 2212 through two connecting pipes 2216, and each transition pipe 2213 is respectively communicated with two adjacent lower annular pipes 2214 through two connecting pipes 2216. More preferably, when the number of the upper annular pipes 2212 and the lower annular pipes 2214 is both 4, the number of the transition pipes 2213 is 3. Among the four upper annular pipes 2212, the materials of every two adjacent upper annular pipes 2212 converge in one transition pipe 2213, and the materials in each transition pipe 2213 are split into two adjacent lower annular pipes 2214.

[0090] In the present invention, the number of layers of the microchannel group 221 is greater than or equal to two layers. For example Figure 4 shows that the number of layers is fifteen layers. Preferably, a temperature measurement port is arranged at the connection of the middle two layers of the microchannel group 221. The first temperature transmitter 32 detects the material temperature through the temperature measurement port, and cooperates with the control component 5 and the circulating cooling device to monitor that the material temperature in the device is within a suitable range.

[0091] Figures 3-5 The microreactor 22 shown in

[0092] The microchannel structure of the present invention has strong mixing and mass transfer effects, greatly improving the heat exchange capacity of the reaction, ensuring that nearly 80% of the reaction can be completed within dozens of seconds in the microchannel, and ensuring that the heat generated during the reaction can be quickly transferred out in a short time.

[0093] The above has elaborated in detail on the embodiments provided by the present invention. Specific examples are used herein to elaborate on the principles and implementation manners of the present invention. The description of the above embodiments is only used to help understand the core idea of the present invention. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the principles of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A reaction device for continuously producing dimethyl sulfoxide, characterized in that, It includes a frame (1) and a reactor assembly (2), a heat exchange assembly (3), a pipeline assembly (4) and a control assembly (5) arranged on the frame (1). The control assembly (5) is connected to the reactor assembly (2), the heat exchange assembly (3) and the pipeline assembly (4). Among them; The pipeline assembly (4) includes a feed pipe (41) and a discharge pipe (42). The feed pipe (41) is communicated with the feed inlet of the reactor assembly (2), and the discharge pipe (42) is communicated with the discharge outlet of the reactor assembly (2). Among them, a material temperature transmitter (43) and a first pressure transmitter (44) are arranged on both the feed pipe (41) and the discharge pipe (42); The heat exchange assembly (3) includes a heat exchange housing (31) and a circulating cooling device. The reactor assembly (2) is located inside the heat exchange housing (31). There is a first heat exchange space between the reactor assembly (2) and the heat exchange housing (31). The circulating cooling device is communicated with the first heat exchange space. The heat exchange housing (31) is also provided with a first temperature transmitter (32), and the first temperature transmitter (32) is connected to the reactor assembly (2); The reactor assembly (2) includes a reactor outer shell (21) and a micro-reactor (22). The micro-reactor (22) is arranged inside the reactor outer shell (21). The micro-reactor (22) is integrally formed by 3D printing or the micro-reactor (22) and the reactor outer shell (21) are integrally formed by 3D printing. There is a second heat exchange space between the micro-reactor (22) and the reactor outer shell (21). The circulating cooling device is communicated with the second heat exchange space. The first temperature transmitter (32) detects the internal temperature of the micro-reactor (22).

2. The reaction device for continuously producing dimethyl sulfoxide according to claim 1, characterized in that, The number of reactor assemblies (2) is greater than or equal to one. Two or more reactor assemblies (2) are arranged in series. The first reactor assembly (2) is communicated with the feed pipe (41), and the last reactor assembly (2) is communicated with the discharge pipe (42). A temperature transmitter is arranged on each reactor assembly (2), and each reactor assembly (2) is communicated with the circulating cooling device.

3. The reaction device for continuously producing dimethyl sulfoxide according to claim 2, wherein Adjacent reactor assemblies (2) are communicated through an auxiliary pipe. A second temperature transmitter and a second pressure transmitter are arranged on the auxiliary pipe, and a three-way check valve is arranged on the auxiliary pipe.

4. The reaction device for continuously producing dimethyl sulfoxide according to any one of claims 1-3, characterized in that, The micro-reactor (22) includes a plurality of layers of micro-channel groups (221) connected in series before and after. The micro-channel group (221) includes one or more channel units, and the multiple channel units are connected in series; The channel unit includes a Y-shaped upper pipe (2211), an upper annular pipe (2212), a transition pipe (2213), a lower annular pipe (2214), a Y-shaped lower pipe (2215) and a connecting pipe (2216). A plurality of transition pipes (2213) are arranged horizontally in the middle of the channel unit. A plurality of upper annular pipes (2212) are arranged above the transition pipes (2213). The upper annular pipes (2212) are communicated with the transition pipes (2213) through the connecting pipes (2216). The Y-shaped upper pipe (2211) is arranged upside down above the upper annular pipes (2212). The bottom branch pipe of the Y-shaped upper pipe (2211) is communicated with the upper annular pipes (2212) through the connecting pipes (2216). A plurality of lower annular pipes (2214) are arranged below the transition pipes (2213). The lower annular pipes (2214) are communicated with the transition pipes (2213) through the connecting pipes (2216). The Y-shaped lower pipe (2215) is arranged below the lower annular pipes (2214). The top branch pipe of the Y-shaped lower pipe (2215) is communicated with the lower annular pipes (2214) through the connecting pipes (2216); The first channel unit in the first layer of microchannel groups (221) serves as the feed end, and the last channel unit is the discharge end. The feed end of the first layer of microchannel groups (221) serves as the material feed end, and the discharge end of the last layer of microchannel groups (221) serves as the material discharge end. In adjacent two layers of microchannel groups (221), the discharge end of the microchannel group (221) in the front position is communicated with the feed end of the microchannel group (221) in the rear position through the connecting pipe (2216).

5. The reaction device for continuously producing dimethyl sulfoxide according to claim 4, characterized in that, In a channel unit, the number of upper annular pipes (2212) is n, where n≥2 and n is an even number. One of the bottom branch pipes of the Y-shaped upper pipe (2211) is communicated with the adjacent n / 2 upper annular pipes (2212), and the other bottom branch pipe of the Y-shaped upper pipe (2211) is communicated with the remaining adjacent n / 2 upper annular pipes (2212); The number of lower annular pipes (2214) is also n, where n≥2 and n is an even number. One of the top branch pipes of the Y-shaped lower pipe (2215) is communicated with the adjacent n / 2 lower annular pipes (2214), and the other top branch pipe of the Y-shaped lower pipe (2215) is communicated with the remaining adjacent n / 2 lower annular pipes (2214).

6. The reaction device for continuously producing dimethyl sulfoxide according to claim 5, characterized in that, In a channel unit, the number of transition pipes (2213) is n - 1. Each transition pipe (2213) is respectively communicated with two adjacent upper annular pipes (2212) through two connecting pipes (2216), and each transition pipe (2213) is respectively communicated with two adjacent lower annular pipes (2214) through two connecting pipes (2216).

7. The reaction device for continuously producing dimethyl sulfoxide according to claim 1, characterized in that, A three-way check valve is provided at the connection between the feed pipe (41) and the reactor assembly (2), and a three-way check valve is provided at the connection between the discharge pipe (42) and the reactor assembly (2).

8. A synthetic process for continuously producing dimethyl sulfoxide, characterized in that, It is applicable to the reaction device for continuously producing dimethyl sulfoxide as described in any one of claims 1 - 7, as follows: Dimethyl sulfide and an oxidant are respectively introduced into the reactor assembly (2) through the feed pipes (41). The delivery amounts of dimethyl sulfide and the oxidant are monitored by the first pressure transmitter (44) to make the oxidant in excess, ensuring that dimethyl sulfide is converted into dimethyl sulfoxide as much as possible. The product is output through the discharge pipe (42), and the output amount of the product is monitored by the first pressure transmitter (44). Set the temperature and start the circulating cooling device. Monitor the temperature of the materials in the microreactor (22) through the first temperature transmitter (32), detect the temperatures of the raw material feed and the product discharge through the material temperature transmitter (43), and cooperate with the circulating cooling device to make the microreactor (22) of the reactor assembly (2) within the set temperature range.

9. The synthesis process according to claim 8, wherein The oxidant is hydrogen peroxide with a mass concentration of 27.5 - 35%, the purity of dimethyl sulfide is ≥99%, and the molar ratio of dimethyl sulfide to hydrogen peroxide is 1:(1.01 - 1.50). Preferably, the molar ratio of dimethyl sulfide to hydrogen peroxide is 1:(1.05 - 1.50).

10. The synthesis process according to claim 9, characterized in that, Dimethyl sulfide and hydrogen peroxide are respectively introduced into the reactor assembly (2). Set the temperature to 55 - 80°C and start the circulating cooling device to make the microreactor (22) of the reactor assembly (2) within the set temperature range.

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