Device for synthesizing dimethyl sulfoxide

Abstract

The invention belongs to the technical field of dimethyl sulfoxide production, and particularly relates to a dimethyl sulfide oxidation production device. The device is characterized in that a 1mm spherical filler layer is arranged in the microreactor, two ends of the filler layer are respectively a feeding side microbubble distributor and a discharge port, the front end of the microbubble distributor is a mixed gas feeding port, the side end of the microbubble distributor is a liquid phase feeding port, the outer side of the reactor is a heat-conducting oil jacket, and a thermometer sleeve is arranged at the top end of the reactor and directly reaches the interior of the reactor. The reactor disclosed by the invention has the beneficial effects that the reactor is small in size, low in liquid holdup in the reactor and more comprehensive in internal temperature monitoring, the temperature in the reactor is more convenient to control, and the risk of out-of-control reaction is reduced; and the reactor is simple in structure, easy to manufacture, convenient to maintain and convenient for industrial amplification.

Description

Technical Field

[0001] The invention belongs to the field of equipment for producing dimethyl sulfoxide by oxidation in the production of dimethyl sulfoxide, and in particular relates to a new reactor device. Background Art

[0002] Dimethyl sulfoxide (DMSO) is a sulfur-containing organic compound with high polarity, high boiling point, good thermal stability, aprotic, and miscible with water. It can dissolve in most organic substances such as ethanol and benzene. It is the most soluble organic solvent and is known as the "universal solvent". Dimethyl sulfoxide has a wide range of applications in defense, textiles, chemicals, medicine, electronic information, carbon fiber and other fields.

[0003] At present, dimethyl sulfoxide is mainly produced by catalytic oxidation of dimethyl sulfide, using nitrogen oxide as a reaction catalyst. At present, dimethyl sulfoxide is commonly produced in a tower. Since dimethyl sulfide has a boiling point of only 38°C, it is easy to vaporize, and its explosion limit is 2.2%-19.7%. Therefore, the current oxidation tower process has the risk of insufficient sulfide reaction and explosion when it encounters oxygen after entering the gas phase space at the top of the tower. For existing oxidation tower equipment, in order to ensure safe production, the reaction temperature in the oxidation tower needs to be strictly controlled, and the oxygen in the feed should be far in excess to ensure that the sulfide reacts completely in the middle section of the oxidation tower. This brings three problems: First, in order to ensure that the reaction can be completed in the reaction tower, the size of the oxidation tower is designed to be relatively large, but because the oxidation reaction itself is a dangerous process, the single-tower production capacity of the oxidation tower is limited under the premise of ensuring safety; second, the nitrogen oxides and sulfoxide materials involved in the production process have strong corrosive effects on metals, and the size of the oxidation tower is large, and the equipment investment and maintenance costs are very high; third, sulfoxide itself is also easy to continue to react with nitrogen oxides at high temperatures to generate by-products such as dimethyl sulfone and even methanesulfonic acid. The amount of by-products in the production process using the oxidation tower is large, the production cost is high, and the amount of three wastes to be treated is large. In the reaction process of producing sulfoxide by the nitrogen oxide method, the gas-liquid two-phase mass transfer is very complicated, involving the shuttle reaction of NO in the gas-liquid two-phase, and the gas phase and liquid phase composition are in non-monotonic dynamic changes. The commonly used heart-shaped continuous flow microreactors on the market are not suitable for this reaction. Summary of the invention

[0004] The purpose of the present invention is to address the bottlenecks in the prior art and first develop a reactor device that can produce dimethyl sulfoxide by oxidizing dimethyl sulfide more safely and effectively.

[0005] Another object of the present invention is to break through the size limitation of the existing oxidation tower and realize the enlargement of the single tower production capacity under the premise of safe production of dimethyl sulfoxide.

[0006] The last object of the present invention is to optimize the reaction equipment in the process of safely producing dimethyl sulfoxide and reduce the equipment investment cost.

[0007] The microchannel reactor for producing dimethyl sulfoxide provided by the present invention has a bottom of the microreactor connected to a microbubble distributor, and a lower end of the microbubble distributor is sealed with an inner cavity of the microreactor, so as to achieve microbubbles being dispersed in the microreactor; The microbubble distributor is provided with a gas phase raw material feed port at the lower end and a liquid phase raw material feed port at the side end, so that the material entering from the gas phase raw material feed port and the material entering from the liquid phase raw material feed port form a vertical contact on the microbubble distributor. A gap for liquid distribution is formed from the connecting part of the liquid phase raw material feed port and the microbubble distributor to the outlet of the microbubble distributor.

[0008] A porous screen is arranged between the upper part of the microreactor and the reaction material collection port; a porous screen is arranged at the connection position between the lower part of the microreactor and the microbubble distributor; The porous screen is a 100-mesh or 50-mesh screen made of stainless steel or ceramic.

[0009] A thermometer sleeve is arranged in the microreactor and extends to the lower part of the microreactor to detect the temperature inside the microreactor.

[0010] In some embodiments, the thermometer sleeve is not in contact with the lower part of the microreactor, and forms a certain cavity, which is a key means to form a confined space.

[0011] A plurality of spherical fillers are filled between the thermometer sleeve and the porous screen to form a filler layer. The particle size of the spherical fillers is 0.5-2 mm, so that a confined reaction area is formed at the lower part of the microreactor.

[0012] In some embodiments, the area inside the microreactor between the upper layer of the distributor screen and the thermometer sleeve screen is filled with spherical fillers with a diameter of 1 mm. The fillers are tightly stacked to form tiny cavities between the filler balls. The surface and cavity structure of the filler balls are called confined reaction intervals. The materials are physically confined in small confined reaction areas, achieving a forced mixing effect and a micro-reaction effect on a microscopic scale.

[0013] The packing layer and the microbubble distributor are in the same vertical plane, and the packing used in the packing layer is selected from any one of zirconium oxide, 321 stainless steel, Hastelloy alloy, quartz, and silicon carbide. The packing in the packing layer is tightly stacked and cannot move inside the reactor.

[0014] The thermometer jacket screen is also embedded in the thermometer sleeve; a limit groove is provided at the connection between the packing layer area and the microbubble distributor and the thermometer jacket screen. The thermometer jacket screen is embedded in the thermometer sleeve, that is, the movable screen is in close contact with the top of the packing layer to limit the movement of the packing.

[0015] A reaction material outlet is arranged on the upper part of the microreactor, and a right angle structure is provided between the packing layer and the reaction material outlet.

[0016] A porous screen is arranged between the upper part of the microreactor and the reaction material collection port; a porous screen is arranged at the connection position between the lower part of the microreactor and the microbubble distributor; A heat transfer oil circulation temperature control jacket is arranged outside the microreactor, and a thermometer sleeve is arranged on the top of the microreactor, which directly reaches the inside of the reactor and is used to detect the temperature inside the microreactor.

[0017] Limiting grooves are provided at the connection between the packing layer area and the microbubble distributor and the thermometer jacket screen.

[0018] In another technical solution of the present invention, the microchannel reactor can also be a plurality of microchannel reactors connected in series or in parallel, and the reaction material extraction ports of two adjacent microreactors connected in series or in parallel are connected to the liquid raw material feed port.

[0019] The multiple microchannel reactors are connected in series or in parallel and further include a premixer. Adjacent microchannel reactor groups are connected via a liquid raw material feed port, and a premixer is arranged between the reaction material extraction port and the liquid raw material feed port of the microreactor.

[0020] The interior of the premixer is a cylinder assembled from corrugated plates of certain specifications, with a maximum dispersion degree of 1-2μm and liquid-liquid and gas-gas phase heterogeneity coefficients of sX≤1~5%.

[0021] The invention also provides a process for synthesizing dimethyl sulfoxide, and the device is used to synthesize dimethyl sulfoxide.

[0022] The steps include: Gas raw material O 2 with NO 2 The mixed gas passes through the gas phase raw material feed port, The liquid raw material is a dimethyl sulfoxide solution of dimethyl sulfide entering the reactor through the liquid raw material feed port. The gas raw material passes through the microbubble distributor and is dispersed in the form of microbubbles and mixed with the liquid raw material to react; The reaction temperature is controlled to be set within the range of 30°C to 90°C. After the reaction is completed, the feed liquid is collected through the discharge port for the next step of treatment.

[0023] In some embodiments, the device is subjected to a balancing treatment before the reaction, that is, after cleaning the device pipeline with dimethyl sulfoxide, N 2 and dimethyl sulfoxide, and the temperature of the reaction section is controlled at 20-40°C by heat transfer oil. After the operation is stable, turn off the N 2 and dimethyl sulfoxide feed.

[0024] In some embodiments, the NO flow rate is controlled to 0 2 1 / 8~1 / 2 of the flow rate.

[0025] In some embodiments, dimethyl sulfide and O 2 The feed molar ratio is 2:0.5-1.

[0026] In some embodiments, the mass concentration of dimethyl sulfide in the dimethyl sulfoxide solution of dimethyl sulfide is 2-90%.

[0027] In some embodiments, the heat generated during the reaction is absorbed by dimethyl sulfoxide and then removed by heat exchange with the heat transfer oil in the temperature control jacket 5 , and the temperature of the reaction zone is monitored by temperature measuring points distributed at different positions in the thermometer sleeve 9 .

[0028] The process carried out by the above-mentioned device is as follows: gas raw material O 2 with NO 2 The mixed gas enters the reactor through the gas phase raw material feed port, and the liquid raw materials dimethyl sulfide and dimethyl sulfoxide enter the reactor through the liquid phase raw material feed port. The gas phase raw material passes through the structured micro bubble distributor and is further dispersed in the form of micro bubbles and mixed with the liquid phase raw material. The micro reactor is filled with fillers to divide the reactor into fixed micro-sized reaction zones. NO 2 Dissolved in a mixed solution of dimethyl sulfoxide and sulfide, the reaction occurs in these micro-sized reaction zones, oxidizing dimethyl sulfide to dimethyl sulfoxide and producing NO and O 2 Reaction to NO 2 Continue to participate in the oxidation of dimethyl sulfide. The heat in the reaction process is absorbed by dimethyl sulfoxide and then removed by heat exchange with the heat transfer oil in the heat transfer oil circulation temperature control jacket. The temperature of the reaction zone is monitored by temperature measuring points distributed at different positions in the thermometer sleeve to control the reaction temperature within the set range. After the reaction is completed, the feed liquid is collected through the reaction material collection port for the next step of processing.

[0029] Compared with the prior art, the present invention has the following beneficial effects: 1. The microchannel reactor of the present invention has a small volume, and the liquid holding capacity in the reactor is reduced by 99% compared with the liquid holding capacity of the traditional tower reactor. The temperature can be strictly controlled at the set temperature, which effectively reduces the occurrence of runaway reaction and the danger of runaway.

[0030] 2. The microchannel reactor of the present invention can effectively solve the complex multiphase mixing problem in the process of producing sulfoxide by sulfide oxidation. The confined reaction zone formed by the internal filler structure ensures that the catalyst, oxidant and reactant are always in a highly mixed and dispersed state, ensuring that the reaction is carried out in a stoichiometric ratio. The content of the reaction by-product dimethyl sulfone is greatly reduced, and the selectivity of dimethyl sulfoxide is improved compared with the traditional tower reactor.

[0031] 3. The microchannel reactor of the present invention has a simple structure, is easy to manufacture, convenient to maintain, and convenient for industrial scale-up.

[0032] 4. The microreactor of the present invention can detect the temperature of each point inside, making it easier to control. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 The schematic diagram of the structure of the microreactor device for synthesizing dimethyl sulfoxide is shown in FIG. 1 , wherein: 1 is a gas-phase raw material feed port; 2 is a liquid-phase raw material feed port; 3 is a microbubble distributor; 4 is a microreactor; 5 is a heat transfer oil circulation temperature control jacket; 6 is a heat transfer oil inlet; 7 is a heat transfer oil outlet; 8 is a reaction material collection port; 9 is a thermometer sleeve; and 10 is a porous screen. DETAILED DESCRIPTION

[0034] Example 1 A microreactor device for synthesizing dimethyl sulfoxide, wherein the bottom of a microreactor 4 is connected to a microbubble distributor 3, and the lower end of the microbubble distributor 3 is sealed with the inner cavity of the microreactor 4, so as to achieve microbubbles being dispersed in the microreactor 4; A gas phase raw material feed port 1 is provided at the lower end of the microbubble distributor 3 , and a liquid phase raw material feed port 2 is provided at the side end of the microbubble distributor 3 , so that the material entering from the gas phase raw material feed port 1 and the material entering from the liquid phase raw material feed port 2 form vertical contact on the microbubble distributor 3 .

[0035] A porous screen 10 is arranged between the upper part of the microreactor 4 and the reaction material collection port 8; a porous screen 10 is arranged at the connection position between the lower part of the microreactor 4 and the microbubble distributor 3; the porous screen 10 is a 100-mesh screen made of stainless steel.

[0036] A thermometer sleeve 9 is provided in the microreactor 4 and extends to the lower part of the microreactor 4 to detect the temperature inside the microreactor 4. A thermometer jacket screen is nested on the thermometer sleeve 9; a plurality of spherical fillers are filled between the thermometer sleeve 9 and the porous screen 10, the spherical fillers are not shown, and a filler layer is formed, and the particle size of the spherical fillers is 1 mm, so that a confined reaction area is formed at the lower part of the microreactor 4, and a limiting groove is provided at the connection between the filler layer area and the microbubble distributor 3 and the thermometer jacket screen.

[0037] The packing layer and the microbubble distributor 3 are in the same vertical plane, and the packing used in the packing layer is selected from silicon carbide.

[0038] A reaction material outlet 8 is arranged on the upper part of the microreactor 4 , and a right angle structure is provided between the packing layer and the reaction material outlet 8 ; a heat transfer oil circulation temperature control jacket 5 is arranged on the outer side of the microreactor 4 .

[0039] Example 2 The single-component microchannel reactor is the same as in Example 1. This embodiment is a series connection of three groups of microchannel reactors in Example 1. The reaction material collection ports of two adjacent microreactors connected in series are connected to the liquid-phase raw material feed port. A premixer is also included. Adjacent microchannel reactor groups are connected through the liquid-phase raw material feed port, and a premixer is arranged between the reaction material collection port and the liquid-phase raw material feed port of the microreactor. The interior of the premixer is a cylinder assembled from corrugated plates of a certain specification, with a maximum dispersion degree of 1-2 μm, and a liquid-liquid phase and gas-gas phase non-uniformity coefficient of s X≤1~5%.

[0040] Example 3 Taking the device of Example 1 as an example, after cleaning the device pipeline with dimethyl sulfoxide, N 2 and dimethyl sulfoxide, and the temperature of the reaction section is controlled at 40°C by heat transfer oil. After the operation is stable, the N 2 and dimethyl sulfoxide feed. Gas feed O 2 with NO 2 The mixed gas enters the reactor through the gas phase raw material feed port 1, and the liquid raw material is a dimethyl sulfoxide solution containing 10% mass concentration of dimethyl sulfide through the liquid phase raw material feed port 2, wherein the gas raw material passes through the structured microbubble distributor 3, and is further dispersed in the form of microbubbles and mixed with the liquid raw material. The dimethyl sulfide flow rate is controlled to be 20 kg / h, and the dimethyl sulfide and O 2 The feed molar ratio is 2:1, and the NO flow rate is controlled to O 2 The microreactor 4 is filled with fillers to divide the reactor into fixed micro-sized reaction zones, NO 2 Dissolved in a mixed solution of dimethyl sulfoxide and sulfide, the reaction occurs in these micro-sized reaction zones, oxidizing dimethyl sulfide to dimethyl sulfoxide and producing NO and O 2 Reaction to NO 2 The heat in the reaction process is absorbed by dimethyl sulfoxide and then removed by heat exchange with the heat transfer oil in the temperature control jacket 5. The temperature of the reaction zone is monitored by the temperature measuring points distributed at different positions in the temperature sensor group 9, and the reaction temperature is controlled to be set within the range of 30°C to 90°C. After the reaction is completed, the feed liquid is collected through the discharge port 8 for the next step of treatment. The experimental results are shown in Table 1.

[0041] Example 4 The process route is the same as that of Example 3, except that the liquid raw material is a dimethyl sulfoxide solution containing 2% to 90% by mass concentration of dimethyl sulfide, which enters the reactor through the liquid raw material feed port 2, and the reaction temperature is controlled to be set at 40°C. After the reaction is completed, the feed liquid is taken out through the discharge port 8 for the next step of treatment. The experimental results are shown in Table 2.

[0042] Example 5 The process route is the same as that of Example 3, except that when the NO flow rate is 0 2 The NO flow rate was adjusted within the range of 1 / 8 to 1 / 2 of the flow rate, the reaction temperature was controlled to be set at 40°C, the reaction was carried out at different NO flow rates and samples were taken to detect the content of each component. The experimental results are shown in Table 3.

[0043] Example 6 The following process is carried out using the apparatus of Example 2, which is the same as the process route of Example 3, except that the flow rate of dimethyl sulfide is adjusted to 50 kg / h to 100 kg / h, and the flow rate of dimethyl sulfoxide, O 2 The NO flow rate was changed year-on-year, and the reaction temperature was controlled to be set at 40°C. After the reaction was completed, the feed liquid was taken out through the discharge port 8 for the next step of treatment. The experimental results are shown in Table 4.

[0044] Comparative Example 1 A conventional tower reactor (oxidation tower) was used. After the reaction device was cleaned with dimethyl sulfoxide, N 2 and dimethyl sulfoxide, and the temperature of the reaction section is controlled at 40°C by heat transfer oil. After the operation is stable, the N 2 and dimethyl sulfoxide as feed, dimethyl sulfoxide as mother liquor at the feed end, and NO 2 Absorb to saturation with dimethyl sulfide: 2 : NO 2 =1:2.5:0.06 (mass ratio) was added with sulfide, and the reaction temperature was controlled to be 80℃ for reaction. After the reaction, the produced liquid was treated with N 2 Stripping of dissolved NO 2 , sampling was performed to detect the content of each component, and the tail gas was absorbed by 48% liquid caustic soda. The experimental results are shown in Table 5.

[0045] Table 1 Relationship between reaction temperature and reaction degree

[0046] Table 2 Relationship between sulfide concentration and reaction degree

[0047] Table 3 Relationship between NO flow rate and reaction degree

[0048] Table 4 Reaction results after multiple reactors are connected in series

[0049] Table 5 Existing process reaction results .

Claims

1. A microreactor device for synthesizing dimethyl sulfoxide, characterized in that: The bottom of the microreactor (4) is connected to the microbubble distributor (3), and the lower end of the microbubble distributor (3) is sealed with the inner cavity of the microreactor (4), so as to achieve the dispersion of microbubbles in the microreactor (4); A gas phase raw material feed port (1) is provided at the lower end of the microbubble distributor (3), and a liquid phase raw material feed port (2) is provided at the side end of the microbubble distributor (3), so that the material entering from the gas phase raw material feed port (1) and the material entering from the liquid phase raw material feed port (2) form vertical contact on the microbubble distributor (3).

2. The microreactor device for synthesizing dimethyl sulfoxide according to claim 1, characterized in that: A porous screen (10) is provided between the upper part of the microreactor (4) and the reaction material collection port (8); a porous screen (10) is provided at the connection position between the lower part of the microreactor (4) and the microbubble distributor (3), and a thermometer jacket screen is also nested on the thermometer sleeve (9); A limiting groove is provided at the connection between the packing layer area, the microbubble distributor (3) and the thermometer jacket screen; The porous screen (10) is a 100-mesh or 50-mesh screen, and is made of stainless steel or ceramic.

3. The microreactor device for synthesizing dimethyl sulfoxide according to claim 2, characterized in that: A thermometer sleeve (9) is provided in the microreactor (4) and extends into the lower part of the microreactor (4) for detecting the temperature inside the microreactor (4).

4. The microreactor device for synthesizing dimethyl sulfoxide according to claim 3, characterized in that: A plurality of spherical fillers are filled between the thermometer sleeve (9) and the porous screen (10) to form a filler layer. The particle size of the spherical fillers is 0.5-2 mm, so that a confined reaction area is formed at the bottom of the microreactor (4).

5. The microreactor device for synthesizing dimethyl sulfoxide according to claim 4, characterized in that: The packing layer and the microbubble distributor (3) are located in the same vertical plane, and the packing used in the packing layer is selected from any one of zirconium oxide, 321 stainless steel, Hastelloy alloy, quartz, and silicon carbide.

6. The microreactor device for synthesizing dimethyl sulfoxide according to claim 4, characterized in that: A reaction material extraction port (8) is provided on the upper part of the microreactor (4), and a right angle structure is provided between the packing layer and the reaction material extraction port (8); a heat transfer oil circulation temperature control jacket (5) is provided on the outer side of the microreactor (4).

7. The microreactor device for synthesizing dimethyl sulfoxide according to any one of claims 1 to 6, characterized in that: The microchannel reactor can also be a plurality of microchannel reactors obtained in any one of claims 1 to 6 connected in series or in parallel, and the reaction material extraction ports of two adjacent micro-reactors connected in series or in parallel are connected to the liquid raw material feed port.

8. The microreactor device for synthesizing dimethyl sulfoxide according to claim 7, characterized in that: It also includes a premixer. Adjacent microchannel reactor groups are connected through a liquid raw material feed port. A premixer is arranged between a reaction material sampling port and a liquid raw material feed port of the microreactor. The interior of the premixer is a cylinder assembled from corrugated plates of a certain specification, with a maximum dispersion degree of 1-2 μm, and a liquid-liquid phase and gas-gas phase non-uniformity coefficient of s X≤1-5%.

9. A process for synthesizing dimethyl sulfoxide, characterized in that: The device according to any one of claims 1 to 8 is used to synthesize dimethyl sulfoxide.

10. The process for synthesizing dimethyl sulfoxide according to claim 9, characterized in that: The steps include: The gas raw material O2 and NO2 mixed gas passes through the gas phase raw material feed port, The liquid raw material is a dimethyl sulfoxide solution of dimethyl sulfide entering the reactor through the liquid raw material feed port. The gas raw material passes through the microbubble distributor and is dispersed in the form of microbubbles and mixed with the liquid raw material to react; The reaction temperature is controlled to be set within the range of 30°C to 90°C. After the reaction is completed, the feed liquid is collected through the discharge port for the next step of treatment.

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