Microreactor device for synthesizing dimethyl sulfoxide

Abstract

The utility model relates to a micro-reactor device for synthesizing dimethyl sulfoxide and belongs to the technical field of dimethyl sulfoxide production. The device is characterized in that a 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 inside of the reactor. The reactor disclosed by the utility model 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] This invention belongs to the field of equipment for the oxidation production of dimethyl sulfoxide in the production of dimethyl sulfoxide, and specifically relates to a new reactor device. Background Technology

[0002] Dimethyl sulfoxide (DMSO) is a sulfur-containing organic compound with high polarity, high boiling point, good thermal stability, aprotic properties, and water miscibility. It is soluble in most organic solvents, including ethanol and benzene, and is considered one of the most powerful organic solvents, earning it the title of "universal solvent." DMSO has a wide range of applications in defense, textiles, chemicals, pharmaceuticals, electronics, and carbon fiber industries.

[0003] Currently, dimethyl sulfoxide (DMSO) is mainly produced through the catalytic oxidation of dimethyl sulfide, using nitrogen oxides as the catalyst. Continuous tower production is commonly used. However, because dimethyl sulfide has a boiling point of only 38°C, it is easily vaporized, and its explosion limits are 2.2%-19.7%. Therefore, current oxidation tower processes pose a risk of incomplete sulfide reaction, leading to an explosion upon contact with oxygen in the gaseous space at the top of the tower. To ensure safe production, existing oxidation tower equipment requires strict control of the reaction temperature within the tower, and a significantly excessive amount of oxygen in the feed to ensure complete sulfide reaction in the middle section of the tower. This leads to three problems: First, to ensure complete reaction within the reaction tower, the oxidation towers are designed to be relatively large. However, since oxidation is a hazardous process, the single-tower capacity is limited while ensuring safety. Second, both nitrogen oxides and sulfoxides involved in the production process have strong corrosive effects on metals, and the large size of the oxidation tower results in high equipment investment and maintenance costs. Third, sulfoxides themselves easily react with nitrogen oxides at high temperatures to generate byproducts such as dimethyl sulfone and even methanesulfonic acid. The production process using oxidation towers results in a large amount of byproducts, high production costs, and a large volume of waste treatment. Furthermore, the gas-liquid two-phase mass transfer in the nitrogen oxide process for producing sulfoxides is very complex, involving the shuttle reaction of NO between the gas and liquid phases. The composition of the gas and liquid phases is in a non-monotonic dynamic change, making commonly used continuous flow microreactors such as heart-shaped reactors unsuitable for this reaction. Summary of the Invention

[0004] The purpose of this invention is to address the bottlenecks in existing technologies by developing a reactor device that can more safely and effectively oxidize dimethyl sulfide to produce dimethyl sulfoxide.

[0005] Another objective of this invention is to overcome the size limitations of existing oxidation towers and achieve a scale-up of single-tower capacity while ensuring safe production of dimethyl sulfoxide.

[0006] The final objective of this invention is to optimize the reaction equipment and reduce equipment investment costs during the safe production of dimethyl sulfoxide.

[0007] The present invention provides a microchannel reactor for producing dimethyl sulfoxide, wherein the bottom of the microreactor is connected to a microbubble distributor, and the lower end of the microbubble distributor is sealed to the inner cavity of the microreactor, so as to achieve microbubble dispersion in the microreactor.

[0008] The microbubble distributor has a gaseous feed inlet at its lower end and a liquid feed inlet at its side end, allowing the feed material from the gaseous feed inlet and the feed material from the liquid feed inlet to make perpendicular contact on the microbubble distributor. A gap is formed between the liquid feed inlet and the outlet of the microbubble distributor to facilitate liquid distribution.

[0009] A porous screen is installed between the upper part of the microreactor and the reactant outlet; a porous screen is also installed at the connection point between the lower part of the microreactor and the microbubble distributor.

[0010] The porous screen is a 100-mesh or 50-mesh screen, made of stainless steel or ceramic.

[0011] The microreactor is equipped with a thermometer sleeve that extends to the bottom of the microreactor to detect the internal temperature.

[0012] In some embodiments, the thermometer sheath does not contact the lower part of the microreactor, forming a cavity. This cavity is a key means of creating a confined space.

[0013] Multiple spherical packing materials are filled between the thermometer sheath and the porous sieve to form a packing layer. The particle size of the spherical packing materials is 0.5-2 mm, which creates a confined reaction zone in the lower part of the microreactor.

[0014] In some embodiments, the area between the upper layer of the distributor screen and the thermometer sleeve screen inside the microreactor is filled with spherical packing material with a diameter of 1 mm. The packing material is tightly packed together, forming tiny cavities between the packing balls. The surface of the packing balls and the cavity structure are called confined reaction zones. The material is physically confined within these small confined reaction zones, achieving a forced mixing effect and a micro-reaction effect at the microscale.

[0015] The packing layer and the microbubble distributor are on the same vertical plane. The packing material used in the packing layer is selected from any one of zirconium oxide, 321 stainless steel, Hastelloy, quartz, and silicon carbide. The packing material in the packing layer is tightly packed and cannot move inside the reactor.

[0016] The thermometer sheath is also fitted with a thermometer jacket screen; a limiting 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 nested on the thermometer sheath, allowing the movable screen to make tight contact with the top of the packing layer, thus restricting the movement of the packing.

[0017] The microreactor has a reactant outlet at the top, and there is a right-angle structure between the packing layer and the reactant outlet.

[0018] A porous screen is installed between the upper part of the microreactor and the reactant outlet; a porous screen is also installed at the connection point between the lower part of the microreactor and the microbubble distributor.

[0019] The microreactor is equipped with a heat transfer oil circulation temperature control jacket on the outside, and a thermometer sleeve is installed at the top of the microreactor, which extends directly into the reactor to detect the temperature inside the microreactor.

[0020] A limiting groove is provided at the connection between the filler layer area and the microbubble distributor and thermometer jacket screen.

[0021] In another technical solution of this utility model, the microchannel reactor can also be multiple microchannel reactors connected in series or in parallel, and the reactant outlet of two adjacent microreactors connected in series or in parallel is connected to the liquid phase feed inlet.

[0022] The multiple microchannel reactors connected in series or in parallel also include a premixer. Adjacent microchannel reactor groups are connected through liquid phase feed inlets, and a premixer is set between the reactant outlet and the liquid phase feed inlet of the microreactor.

[0023] The premixer is a cylinder assembled from corrugated plates of a certain specification. The maximum dispersion is 1-2 μm, and the non-uniformity coefficient between the liquid-liquid phase and the gas-gas phase is sX≤1~5%.

[0024] The process using the above-mentioned apparatus is as follows: A mixture of gaseous raw materials O2 and NO2 enters the reactor through the gaseous raw material inlet, while dimethyl sulfide and dimethyl sulfoxide enter through the liquid raw material inlet. The gaseous raw materials pass through a structured microbubble distributor, where they are further dispersed in the form of microbubbles and mixed with the liquid raw materials. The microreactor is filled with packing material, which divides the reactor into fixed micro-sized reaction zones. NO2 dissolves in the mixed solution of dimethyl sulfoxide and sulfide, and a reaction occurs in these micro-sized reaction zones, oxidizing dimethyl sulfide to dimethyl sulfoxide and producing NO. NO reacts with O2 to become NO2, which continues to participate in the oxidation of dimethyl sulfide. The heat generated during the reaction is absorbed by dimethyl sulfoxide and removed through 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 locations in the thermometer sleeve, and the reaction temperature is controlled within the set range. After the reaction is completed, the liquid is collected through the reaction material outlet for further processing.

[0025] Compared with the prior art, this utility model has the following advantages:

[0026] 1. The microchannel reactor of this invention has a small volume, and the liquid holding capacity inside the reactor is reduced by 99% compared with the traditional tower reactor. The temperature can be strictly controlled at the set temperature, which effectively reduces the occurrence of reaction runaway and the danger when runaway occurs.

[0027] 2. The microchannel reactor of this 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 packing structure ensures that the catalyst, oxidant and reactants are always in a highly mixed and dispersed state, ensuring that the reaction proceeds in stoichiometric proportions. The content of the reaction byproduct dimethyl sulfone is greatly reduced, and the selectivity of dimethyl sulfone is improved compared with the traditional tower reactor.

[0028] 3. The microchannel reactor of this invention has a simple structure, is easy to manufacture, convenient to maintain, and is easy to scale up industrially.

[0029] 4. The microreactor of this invention can detect the temperature at various points inside, making it easier to control. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of a microreactor device for synthesizing dimethyl sulfoxide, wherein 1-gas phase feed inlet; 2-liquid phase feed inlet; 3-microbubble distributor; 4-microreactor; 5-heat transfer oil circulation temperature control jacket; 6-heat transfer oil inlet; 7-heat transfer oil outlet; 8-reactant outlet; 9-thermometer sleeve; 10-porous screen. Detailed Implementation

[0031] Example 1

[0032] A microreactor device for synthesizing dimethyl sulfoxide, wherein the bottom of the microreactor 4 is connected to a microbubble distributor 3, and the lower end of the microbubble distributor 3 is sealed to the inner cavity of the microreactor 4, so as to achieve the dispersion of microbubbles in the microreactor 4;

[0033] The microbubble distributor 3 has a gas phase feed inlet 1 at its lower end and a liquid phase feed inlet 2 at its side end, so that the material entering from the gas phase feed inlet 1 and the material entering from the liquid phase feed inlet 2 form a vertical contact on the microbubble distributor 3.

[0034] A porous screen 10 is provided between the upper part of the microreactor 4 and the reactant outlet 8; a porous screen 10 is also provided 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 and is made of stainless steel.

[0035] A thermometer sleeve 9 is installed inside the microreactor 4, extending to the lower part of the microreactor 4, for detecting the internal temperature of the microreactor 4. A thermometer jacket screen is nested on the thermometer sleeve 9; multiple spherical packing materials (not shown) are filled between the thermometer sleeve 9 and the porous screen 10, forming a packing layer. The particle size of the spherical packing materials is 1 mm, which creates a confined reaction zone in the lower part of the microreactor 4. A limiting groove is provided at the connection between the packing layer region and the microbubble distributor 3 and the thermometer jacket screen.

[0036] The filler layer and the microbubble distributor 3 are on the same vertical plane, and the filler used in the filler layer is selected from silicon carbide.

[0037] The microreactor 4 is provided with a reactant outlet 8 at the top, and there is a straight-turn structure between the packing layer and the reactant outlet 8; a heat transfer oil circulation temperature control jacket 5 is provided on the outside of the microreactor 4.

[0038] Example 2

[0039] The single-component microchannel reactor is the same as in Example 1; however, this example consists of three sets of microchannel reactors from Example 1 connected in series. The reactant outlets of two adjacent microreactors connected in series are connected to the liquid feed inlets. A premixer is also included; adjacent microchannel reactor sets are connected via liquid feed inlets, and a premixer is placed between the reactant outlet and the liquid feed inlet of the microreactor. The premixer's interior consists of a cylinder assembled from corrugated plates of a specific size, with a maximum dispersion of 1-2 μm and a liquid-liquid and gas-gas phase non-uniformity coefficient of sX ≤ 1~5%.

[0040] Example 3

[0041] Taking the apparatus of Example 1 as an example, after cleaning the pipeline of the dimethyl sulfoxide (DMSO) device, N2 and DMSO are circulated, and the temperature of the reaction section is controlled at 40°C by heat transfer oil. After the operation is stable, the N2 and DMSO feed are shut off. The gaseous raw material O2 and NO2 mixture enters the reactor through the gas phase feed inlet 1, and the liquid raw material is a DMSO solution containing 10% mass concentration of dimethyl sulfide enters the reactor through the liquid phase feed inlet 2. The gaseous raw material passes through the microbubble distributor of structure 3, and is further dispersed in the form of microbubbles to mix with the liquid raw material. The flow rate of dimethyl sulfide is controlled at 20 kg / h, the feed molar ratio of dimethyl sulfide and O2 is controlled at 2:1, and the NO flow rate is controlled at 1 / 4 of the O2 flow rate for the reaction. Microreactor 4 is filled with packing material that divides the reactor interior into fixed micro-sized reaction zones. NO2 dissolves in a mixed solution of dimethyl sulfoxide and sulfide, and a reaction occurs within these micro-sized reaction zones, oxidizing dimethyl sulfide to dimethyl sulfoxide. NO is then produced, which reacts with O2 to become NO2, further participating in the oxidation of dimethyl sulfide. The heat generated during the reaction is absorbed by the dimethyl sulfoxide and removed through heat exchange with the heat-conducting oil in the temperature control jacket 5. The temperature of the reaction zone is monitored by temperature measuring points distributed at different locations in the thermometer sleeve 9, and the reaction temperature is controlled within the range of 30℃ to 90℃. After the reaction is complete, the liquid is collected through the outlet 8 for further processing. The experimental results are shown in Table 1.

[0042] Example 4

[0043] The following process was carried out using the apparatus of Example 2, with the same process route as in Example 3. The dimethyl sulfide flow rate was adjusted from 50 kg / h to 100 kg / h, and the flow rates of dimethyl sulfoxide, O2, and NO were changed accordingly. The reaction temperature was controlled at 40°C. After the reaction, the liquid was collected through outlet 8 for further processing. The experimental results are shown in Table 2.

[0044] Table 1 Relationship between reaction temperature and degree of reaction

[0045]

[0046] Table 2. Reaction results after multiple reactors are connected in series.

[0047] .

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 to the inner cavity of the microreactor (4) to achieve microbubble dispersion in the microreactor (4); The microbubble distributor (3) has a gas phase feed inlet (1) at the lower end and a liquid phase feed inlet (2) at the side end, so that the material entering from the gas phase feed inlet (1) and the material entering from the liquid phase feed inlet (2) form a 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 reactant outlet (8); a porous screen (10) is provided 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 or 50-mesh screen, made of stainless steel or ceramic.

3. The microreactor device for synthesizing dimethyl sulfoxide according to claim 2, characterized in that, The microreactor (4) is equipped with a thermometer sleeve (9) that extends into the lower part of the microreactor (4) to detect the temperature inside the microreactor (4).

4. The microreactor device for synthesizing dimethyl sulfoxide according to claim 3, characterized in that, Multiple spherical packing materials are filled between the thermometer sleeve (9) and the porous screen (10) to form a packing layer. The particle size of the spherical packing materials is 0.5-2 mm, so that a confined reaction zone is formed in the lower part of the microreactor (4).

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

6. The microreactor device for synthesizing dimethyl sulfoxide according to claim 4, characterized in that, A thermometer jacket screen is nested on the thermometer sleeve (9); A limiting groove is provided at the connection between the filler layer area and the microbubble distributor (3) and the thermometer jacket screen.

7. The microreactor apparatus for synthesizing dimethyl sulfoxide according to claim 6, characterized in that, The microreactor (4) is provided with a reactant outlet (8) at the top, and there is a straight-turn structure between the packing layer and the reactant outlet (8); a heat transfer oil circulation temperature control jacket (5) is provided on the outside of the microreactor (4).

8. The microreactor apparatus for synthesizing dimethyl sulfoxide according to any one of claims 1-7, characterized in that: The microreactor device can also be a series or parallel connection of microchannel reactors as claimed in any one of claims 1-7, with the reactant outlet of two adjacent series or parallel microreactor devices connected to the liquid phase feed inlet.

9. The microreactor device for synthesizing dimethyl sulfoxide according to claim 8, characterized in that: It also includes a premixer. Adjacent microreactor units are connected via a liquid feed inlet, and a premixer is installed between the reactant outlet and the liquid feed inlet of the microreactor.

10. The microreactor device for synthesizing dimethyl sulfoxide according to claim 9, characterized in that: The premixer is a cylinder assembled from corrugated plates of a certain size.

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