WO2025147835A1 - Dimethyl sulfoxide synthesis system and synthesis method - Google Patents

Abstract

A dimethyl sulfoxide synthesis system and a synthesis method, the system comprising: a fixed bed reactor (2) used to synthesize dimethyl sulfide, and an oxidation reactor (4) used to synthesize dimethyl sulfoxide. An external intensification unit (9) is disposed outside the oxidation reactor (4), the external intensification unit (9) comprising a first intensification reactor (901) and a second intensification reactor (902), the first intensification reactor (901) being disposed above the second intensification reactor (902), the first intensification reactor (901) being connected to a discharge port at a bottom end of the fixed bed reactor (2), the second intensification reactor (902) being connected to a nitrogen dioxide or oxygen storage tank (13), a connecting pipe (903) being disposed between the first intensification reactor (901) and the second intensification reactor (902), and a static mixer (904) being disposed in the connecting pipe (903).

Description

A kind of synthesis system and synthesis method of dimethyl sulfoxide Technical Field

The invention belongs to the technical field of dimethyl sulfoxide production, and in particular belongs to a synthesis system and a synthesis method of dimethyl sulfoxide.

Background Art

Dimethyl sulfoxide is an extremely important organic solvent in the fields of medicine, chemical engineering and materials science. In industry, the synthesis of dimethyl sulfoxide mainly adopts several methods: nitric acid method, hydrogen peroxide method, ozone method and nitrogen dioxide method. Among them, the nitrogen dioxide method has become the mainstream industrial production method due to its high production efficiency and low safety risk. In this method, liquid phase oxidation and gas phase oxidation are two commonly used processes. Liquid phase oxidation usually uses methanol and hydrogen sulfide as raw materials, generates dimethyl sulfide under the action of γ-alumina, and then uses nitrogen dioxide or oxygen for oxidation reaction to produce crude dimethyl sulfoxide, and finally obtains refined dimethyl sulfoxide by vacuum distillation.

Although the liquid phase oxidation method has advantages in industrial production, it still has some problems and disadvantages. The reaction conditions of the liquid phase oxidation method are difficult to control, and the traditional process has low raw material conversion rate and low product purity in the process of synthesizing dimethyl sulfoxide.

In view of this, the present invention is proposed.

Summary of the invention

The first purpose of the present invention is to provide a synthesis system of dimethyl sulfoxide. The system aims at solving the problems of low raw material conversion rate and difficult control of reaction conditions in the prior art, designs a reasonable process flow, and based on the enhanced reaction technology, the raw materials are crushed and dispersed into micron-sized bubbles through an enhanced reactor, thereby greatly improving the mass transfer rate of gas-phase raw materials to reaction liquid and the macroscopic reaction rate, thereby improving the raw material conversion rate.

The second object of the present invention is to provide a method for synthesizing dimethyl sulfoxide using the above-mentioned dimethyl sulfoxide synthesis system, which is simple to operate, has milder operating conditions, and has low energy consumption, achieving a better treatment effect than the prior art process.

In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are particularly adopted:

The present invention provides a synthesis system of dimethyl sulfoxide, comprising:

A fixed bed reactor for synthesizing dimethyl sulfide and an oxidation reactor for synthesizing dimethyl sulfoxide;

An external enhancement unit is arranged outside the oxidation reactor, and the external enhancement unit includes a first enhancement reactor and a second enhancement reactor. The first enhancement reactor is arranged above the second enhancement reactor, and the first enhancement reactor is connected to the discharge port at the bottom end of the fixed bed reactor. The second enhancement reactor is connected to a nitrogen dioxide or oxygen storage tank. A connecting pipe is arranged between the first enhancement reactor and the second enhancement reactor, and a static mixer is arranged in the connecting pipe.

In the prior art, the following problems mainly exist in the synthesis of dimethyl sulfoxide: the incomplete reaction of the traditional process for synthesizing dimethyl sulfoxide leads to a low raw material conversion rate, which means that in the dimethyl sulfide oxidation stage, the raw material is not completely converted into the target product, thereby reducing the overall production efficiency and economy; at the same time, in the process of synthesizing dimethyl sulfoxide in the prior art, the reaction energy consumption is high, the reaction temperature and pressure of the oxidation reactor are high, and the production capacity is relatively low.

In order to solve the above technical problems, the present invention provides a dimethyl sulfoxide synthesis system. The overall structure of the synthesis system is simple. By arranging an external strengthening unit outside the oxidation reactor, the raw materials entering the oxidation reactor can be initially crushed and dispersed, and the dimethyl sulfide liquid and nitrogen dioxide gas or oxygen can be crushed and dispersed into micron-sized microbubbles, thereby increasing the phase boundary mass transfer area between the gas and liquid phases, thereby improving the raw material conversion rate. In the external strengthening unit of the present invention, the first strengthening reactor is arranged above the second strengthening reactor. This is arranged because dimethyl sulfide liquid is introduced into the first strengthening reactor, and nitrogen dioxide or oxygen is introduced into the second strengthening reactor. The liquid flows from top to bottom, and the gas moves upward from bottom to top, thereby increasing the contact time between the two. At the same time, the present invention is provided with a connecting pipe between the first strengthening reactor and the second strengthening reactor, which can provide a mixing place for the gas and liquid phases. At the same time, in the connecting pipe, The static mixer disposed inside the pipeline can cooperate with the enhanced reactor to more evenly mix the microbubbles coming out of the enhanced reactor, so that the microbubbles generated by the enhanced reactor can more effectively contact the surrounding fluid, thereby improving the reaction efficiency.

Preferably, the oxidation reactor is provided with a built-in strengthening unit, the built-in strengthening unit includes a third strengthening reactor arranged at the top of the oxidation reactor and a fourth strengthening reactor arranged below the third strengthening reactor, the third strengthening reactor is connected to the connecting pipe, and the fourth strengthening reactor is connected to the nitrogen dioxide or oxygen storage tank. By providing a built-in strengthening unit, it forms a strengthening system with the external strengthening unit arranged outside the oxidation reactor, and the built-in strengthening reactor can perform secondary crushing and dispersion on the mixed material entering the oxidation reactor, breaking the reaction raw materials into extremely small micron-sized bubbles, and further improving the phase boundary mass transfer area. At the same time, the fourth strengthening reactor of the present invention is directly connected to the nitrogen dioxide or oxygen storage tank, and the purpose of such a setting is to ensure that the carbon dioxide or oxygen in the oxidation reactor is excessive, so that dimethyl sulfide is fully reacted.

Preferably, the outlet of the third enhanced reactor is opposite to the outlet of the fourth enhanced reactor, the outlet of the third enhanced reactor is connected with a nozzle, and the outlet of the fourth enhanced reactor is provided with an agitator. By placing the outlets of the third enhanced reactor and the fourth enhanced reactor with the built-in enhanced unit opposite to each other, hedging can be achieved. By setting a nozzle at the outlet of the third enhanced reactor, it is used in conjunction with the third enhanced reactor to accurately control the flow rate of the microbubbles coming out of the third enhanced reactor, and at the same time, the microbubbles are uniformly sprayed inside the oxidation reactor to achieve the effect of efficient mixing; the outlet of the fourth enhanced reactor of the present invention is provided with an agitator, and the purpose of such setting is that the fourth enhanced reactor comes out with nitrogen dioxide gas or oxygen, which needs to be fully reacted with the dimethyl sulfide liquid coming out of the third enhanced reactor, and the third enhanced reactor is arranged above, so the agitator is provided to not only evenly diffuse the gas coming out of the fourth enhanced reactor, but also can be used in conjunction with the third enhanced reactor to stir and mix the dimethyl sulfide liquid coming out of the third enhanced reactor with the gas coming out of the fourth enhanced reactor, thereby improving the conversion rate between the raw materials.

Preferably, a flow dividing assembly is arranged directly below the built-in strengthening unit, and the flow dividing assembly includes a plurality of flow dividing plates arranged sequentially from top to bottom, and the interval between two adjacent flow dividing plates gradually becomes The diverter assembly of the present invention is arranged below the built-in strengthening unit. The advantage of such arrangement is that the reaction time between the microbubble mixed materials coming out of the built-in strengthening reactor can be prolonged. The interval between two adjacent diverter plates gradually becomes smaller, which can enhance the turbulence in the fluid, thereby improving the mixing effect; at the same time, it can effectively control the speed of the fluid, reduce the energy loss caused by fluid friction or turbulence, and improve the energy efficiency of the overall system.

Preferably, the diverter plate is provided with diverter holes, and the pore size of the diverter holes is 50-100 μm. The pore size on the diverter plate of the present invention is set to a micron-level pore size, which can filter out large bubbles, thereby improving the overall reaction efficiency.

Preferably, the static mixer is a spiral metal tube, which extends spirally along the longitudinal axis of the connecting pipe, and the length of the spiral metal tube is adapted to that of the connecting pipe.

Preferably, the surface of the spiral metal tube is provided with through holes.

By selecting a spiral metal tube, the reaction time can be prolonged, while guiding the fluid to flow in a more effective manner, reducing turbulence and fluid resistance, and improving heat exchange efficiency; at the same time, providing through holes can reduce the resistance of the fluid in the pipeline.

Preferably, the crude product outlet at the bottom of the oxidation reactor is connected to a vacuum distillation tower, and the side wall of the vacuum distillation tower is connected to the third enhanced reactor to recover unreacted raw materials. By setting up the vacuum distillation tower, the unreacted raw materials are returned to the oxidation reactor for further reaction, thereby improving the conversion rate of the raw materials.

In the present invention, by arranging a fixed bed reactor and an oxidation reactor, a stable reaction environment can be provided for synthesizing dimethyl sulfide and converting dimethyl sulfide into dimethyl sulfoxide; at the same time, an external strengthening unit is arranged outside the oxidation reactor, and the gas-liquid two-phase raw materials can be converted into micron-sized bubbles through the coordinated action of the first strengthening reactor and the second strengthening reactor, thereby increasing the gas-liquid two-phase interface mass transfer area; the internal strengthening unit is used in coordination with the external strengthening unit to form an strengthening system, and the mixed material entering the oxidation reactor is further crushed and dispersed, thereby improving the reaction efficiency and the selectivity of the raw materials.

The present invention provides a connecting pipe in the external strengthening unit, and a static mixer is provided inside the connecting pipe. By providing the connecting pipe, the uniform mixing of materials can be promoted, which plays a role in supporting the first strengthening unit. The static mixer has the functions of the first and second enhanced reactors; at the same time, the two ends of the static mixer are respectively connected to the first enhanced reactor and the second enhanced reactor, which can make the reaction raw materials coming out of the enhanced reactor be evenly mixed, filter out large bubbles through the through holes, and increase the reaction rate.

The present invention connects nozzles and stirrers to the ends of two enhanced reactors of the built-in enhanced unit respectively, so that the microbubbles coming out of the enhanced reactors can be stirred and mixed in time, thereby further improving the reaction rate and the conversion rate of the raw materials. At the same time, a diversion component is arranged below the built-in enhanced reactor, which is used in conjunction with the built-in enhanced unit to filter the mixed materials coming out of the built-in enhanced unit, ensuring that the microbubbles flowing into the bottom of the oxidation reactor are all micron-level microbubbles, and at the same time can prolong the reaction time and improve the conversion rate of the raw materials.

Those skilled in the art will appreciate that the enhanced reactor used in the present invention has been embodied in the inventor's prior patents, such as patents with application numbers CN201610641119.6, CN201610641251.7, CN201710766435.0, CN106187660, CN105903425A, CN109437390A, CN205833127U and CN207581700U. The prior patent CN201610641119.6 describes in detail the specific product structure and working principle of the micron bubble generator (i.e., enhanced reactor). The application document states that "the micron bubble generator includes a main body and a secondary crushing member, a cavity is provided in the main body, an inlet connected to the cavity is provided on the main body, the first and second opposite ends of the cavity are open, wherein the cross-sectional area of the cavity decreases from the middle of the cavity to the first and second ends of the cavity; the secondary crushing member is provided at at least one of the first and second ends of the cavity, a part of the secondary crushing member is provided in the cavity, and an annular channel is formed between the secondary crushing member and the through holes open at both ends of the cavity. The micron bubble generator also includes an air inlet pipe and a liquid inlet pipe." From the specific structure disclosed in the application document, it can be known that its specific working principle is: the liquid enters the micron bubble generator tangentially through the liquid inlet pipe, rotates at ultra-high speed and cuts the gas, so that the gas bubbles are broken into micron-level microbubbles, thereby increasing the mass transfer area between the liquid phase and the gas phase, and the micron bubble generator in the patent belongs to a pneumatic enhanced reactor.

In addition, the prior patent 201610641251.7 records that the primary bubble breaker has a circulating liquid inlet, a circulating gas inlet and a gas-liquid mixture outlet, and the secondary bubble breaker connects the feed inlet with the gas-liquid mixture outlet, indicating that the bubble breaker requires gas-liquid mixture to enter. In addition, it can be seen from the following figures that The primary bubble breaker mainly uses circulating fluid as power, so in fact the primary bubble breaker belongs to a hydraulic enhanced reactor. The secondary bubble breaker simultaneously passes the gas-liquid mixture into an elliptical rotating ball for rotation, thereby achieving bubble breaking during the rotation process, so the secondary bubble breaker actually belongs to a gas-liquid linkage enhanced reactor. In fact, both the hydraulic enhanced reactor and the gas-liquid linkage enhanced reactor are a specific form of enhanced reactor. However, the enhanced reactor used in the present invention is not limited to the above-mentioned forms. The specific structure of the bubble breaker recorded in the prior patent is only one of the forms that can be adopted by the enhanced reactor of the present invention.

In addition, the prior patent 201710766435.0 records that "the principle of the bubble breaker is a high-speed jet to achieve mutual collision of gases", and also explains that it can be used in a micro-interface enhanced reactor, verifying the correlation between the bubble breaker and the micro-interface generator itself; and the prior patent CN106187660 also has relevant records on the specific structure of the bubble breaker, see paragraphs [0031]-[0041] in the specification, and the attached drawings, which have a detailed description of the specific working principle of the bubble breaker S-2. The top of the bubble breaker is a liquid phase inlet, and the side is a gas phase inlet. The liquid phase coming in from the top provides suction power, thereby achieving the effect of crushing into ultrafine bubbles. It can also be seen in the attached drawings that the bubble breaker has a conical structure, and the diameter of the upper part is larger than the diameter of the lower part, so that the liquid phase can better provide suction power.

Since the enhanced reactor was just developed in the early stage of the prior patent application, it was named micron bubble generator (CN201610641119.6), bubble breaker (201710766435.0), etc. in the early stage. With the continuous technical improvement, it was later renamed as enhanced reactor. Now the enhanced reactor in the present invention is equivalent to the previous micron bubble generator, bubble breaker, etc., but the name is different. In summary, the enhanced reactor of the present invention belongs to the prior art.

Preferably, the synthesis system of dimethyl sulfoxide of the present invention further comprises a heating furnace, an azeotropic distillation tower, a neutralization evaporation reactor, an incinerator and a wastewater storage tank;

The heating furnace is connected to the feed port of the fixed bed reactor, and the heating furnace is used to preheat methanol and hydrogen sulfide;

The azeotropic distillation tower is arranged between the fixed bed reactor and the oxidation reactor. The boiling distillation tower is used to purify the dimethyl sulfide coming out of the fixed bed reactor;

The neutralization evaporation reactor is arranged between the oxidation reaction kettle and the azeotropic distillation tower to filter and remove impurities from dimethyl sulfoxide;

The incinerator is respectively connected to the fixed bed reactor, the azeotropic distillation tower, the oxidation reactor, the neutralization evaporation reactor and the vacuum distillation tower;

The wastewater storage tank is connected to the vacuum distillation tower to store wastewater.

The synthesis system of the present invention is more perfect by arranging a heating furnace, an azeotropic distillation tower, a neutralization evaporation reactor, an incinerator and a wastewater storage tank. At the same time, the comprehensive system design ensures the continuity and efficiency of the production process and reduces environmental pollution.

In addition, the present invention also provides a method for synthesizing dimethyl sulfoxide, and the dimethyl sulfoxide is synthesized using the above-mentioned synthesis system.

Preferably, the method for synthesizing dimethyl sulfoxide comprises the following steps: synthesizing dimethyl sulfide by using methanol and hydrogen sulfide, and subjecting dimethyl sulfide to an oxidation reaction with nitrogen dioxide or oxygen to generate dimethyl sulfoxide.

Preferably, the reaction temperature during the oxidation reaction is 30-50° C., and the reaction pressure is 0.1-0.2 MPa.

The synthesis method of the invention is easy to operate, the operating conditions are milder, and the product quality is higher.

Compared with the prior art, the present invention has the following beneficial effects:

(1) The present invention sets an external strengthening unit outside the oxidation reactor to crush and disperse the raw materials entering the oxidation reactor, thereby improving the mass transfer effect between the reaction materials and improving the reaction efficiency.

(2) The oxidation reactor of the present invention is provided with a built-in strengthening unit, and is used in conjunction with a diversion component, which can effectively crush and disperse the reaction raw materials, while extending the reaction time and improving the conversion rate of the raw materials.

(3) The present invention connects an azeotropic distiller and a vacuum distillation tower after the fixed bed reactor and the oxidation reactor, respectively, so as to purify and refine the intermediate product dimethyl sulfide and the final product dimethyl sulfoxide, respectively, thereby improving the product quality.

BRIEF DESCRIPTION OF THE DRAWINGS

Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

FIG1 is a schematic flow diagram of a system for synthesizing dimethyl sulfoxide provided in Example 1 of the present invention;

FIG2 is a partial enlarged view of the static mixer provided in Example 1 of the present invention;

FIG3 is a schematic diagram of the structure of the diverter plate provided in Example 1 of the present invention.

in:
1-Heating furnace; 2-Fixed bed reactor;
3-azeotropic distillation tower; 4-oxidation reactor;
401-diverter assembly; 4011-diverter plate;
4012-diverter hole; 5-neutralization evaporation reactor;
6- vacuum distillation tower; 7- wastewater storage tank;
8-Incinerator; 9-External enhanced unit;
901-first enhanced reactor; 902-second enhanced reactor;
903-connecting pipeline; 904-static mixer;
9041-Spiral metal tube; 9042-Through hole;
10- built-in enhanced unit; 101- third enhanced reactor;
102- fourth enhanced reactor; 103- nozzle;
104- agitator; 11- hydrogen sulfide storage tank;
12-Methanol storage tank; 13-Nitrogen dioxide or oxygen storage tank.

DETAILED DESCRIPTION

The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and specific implementation methods. However, those skilled in the art will understand that the embodiments described below are only part of the embodiments of the present invention, rather than all of the embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. If the specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments is not specified, they are all conventional products that can be purchased commercially.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

In order to more clearly explain the technical solution of the present invention, it is described in the form of specific embodiments below.

Example 1

1-3, a synthesis system of dimethyl sulfoxide according to an embodiment of the present invention is shown, comprising a heating furnace 1, a fixed bed reactor 2 for synthesizing dimethyl sulfide, an azeotropic distillation tower 3 for refining crude dimethyl sulfide, an oxidation reactor 4 for synthesizing dimethyl sulfoxide, a neutralization evaporation reactor 5 and a vacuum distillation tower 6 connected in sequence; the heating furnace 1 is connected to the feed port of the fixed bed reactor 2; the azeotropic distillation tower 3 is connected to the discharge port at the bottom end of the fixed bed reactor 2; the azeotropic distillation tower 3 is connected to the oxidation reactor 4; wherein an external strengthening unit 9 is arranged outside the oxidation reactor 4, and the external strengthening unit 9 includes a first strengthening reactor 901 and a second strengthening reactor 902; the first strengthening reactor 901 is connected to the bottom end of the azeotropic distillation tower 3, the second strengthening reactor 902 is connected to the nitrogen dioxide or oxygen storage tank 13, and the first strengthening reactor 901 is connected to the A connecting pipe 903 is provided between the second enhanced reactors 902 , and a static mixer 904 is provided in the connecting pipe 903 .

As shown in Figure 2, the static mixer 904 in the present invention is a spiral metal tube 9041, which extends spirally along the longitudinal axis of the connecting pipe 903, and the spiral metal tube 9041 is adapted to the length of the connecting pipe 903. Specifically, the surface of the spiral metal tube 9041 of the present invention is provided with multiple through holes 9042.

In this embodiment, a built-in enhanced unit 10 is provided inside the oxidation reactor 4, and the built-in enhanced unit 10 includes a third enhanced reactor 101 provided at the top of the oxidation reactor 4 and a fourth enhanced reactor 102 provided below the third enhanced reactor 101, the third enhanced reactor 101 is connected to the outlet of the connecting pipe 903, and the fourth enhanced reactor 102 is connected to the nitrogen dioxide or oxygen storage tank 13. Specifically, the outlet of the third enhanced reactor 101 is opposite to the outlet of the fourth enhanced reactor 102, the outlet of the third enhanced reactor 101 is connected to a nozzle 103, and the outlet of the fourth enhanced reactor 102 is provided with an agitator 104. The side wall of the vacuum distillation tower 6 of the present invention is connected to the third enhanced reactor 101 to recover unreacted raw materials.

A flow divider assembly 401 is disposed directly below the built-in strengthening unit 10 of the present invention. The flow divider assembly 401 includes a plurality of flow divider plates 4011 disposed sequentially from top to bottom, and the interval between two adjacent flow divider plates 4011 gradually decreases. Specifically, as shown in FIG3 , a flow divider hole 4012 is disposed on the flow divider plate 4011, and the aperture of the flow divider hole 4012 is 50-100 μm.

The dimethyl sulfoxide synthesis system of the present invention also includes an incinerator 8 and a wastewater storage tank 7; the incinerator 8 is respectively connected to the top of the fixed bed reactor 2, the azeotropic distillation tower 3, the oxidation reactor 4, the neutralization evaporation reactor 5 and the vacuum distillation tower 6 to remove the waste gas generated by the reaction; the wastewater storage tank 7 is connected to the vacuum distillation tower 6 to store wastewater.

The synthesis system of dimethyl sulfoxide of the present invention comprises the following process flow when it is actually applied:

The hydrogen sulfide gas and methanol gas from the upstream hydrogen sulfide storage tank 11 and the methanol storage tank 12 are preheated by the heating furnace 1; they are introduced into the fixed bed reactor 2 to react with the catalyst in the fixed bed reactor 2 to generate crude dimethyl sulfide; the crude dimethyl sulfide enters the azeotropic distillation tower 3 through the material outlet at the bottom of the fixed bed reactor 2 to remove moisture from the crude dimethyl sulfide by azeotropic distillation; the dimethyl sulfide after distillation and purification Methyl sulfide enters the external strengthening unit 9, and the nitrogen dioxide gas or oxygen in the nitrogen dioxide or oxygen storage tank 13 enters the external strengthening unit 9 for initial crushing, dispersion and mixing; then the mixed material is passed into the oxidation reactor 4 for oxidation reaction to generate crude dimethyl sulfoxide; then the crude dimethyl sulfoxide enters the neutralization evaporation reactor 5 for neutralization, evaporation, concentration and desalination; then it is passed into the vacuum distillation tower 6 and the finished dimethyl sulfoxide is prepared by the vacuum distillation method; the waste gas generated during the reaction is subjected to high-temperature treatment by the incinerator 8, and the waste water generated by the reaction is passed into the waste water storage tank 7 and transported to the subsequent waste water treatment unit.

Example 2

The only difference between this example and Example 1 is that the static mixer is a straight-flow metal tube.

Example 3

The only difference between this example and Example 1 is that the spacing between each diverter plate is equal.

Example 4

The only difference between this example and Example 1 is that the diameter of the diversion hole is 10 mm.

Comparative Example 1

The only difference between this example and Example 1 is that no external strengthening unit is provided.

Comparative Example 2

The only difference between this example and Example 1 is that no built-in strengthening unit is provided.

Comparative Example 3

The only difference between this example and Example 1 is that no diversion component is provided.

Comparative Example 4

This example adopts the existing technology to directly oxidize dimethyl sulfide produced by hydrogen sulfide gas and methanol gas with nitrogen dioxide to produce dimethyl sulfoxide.

Experimental Example 1

The systems of Examples 1-4 and Comparative Examples 1-3 were used to synthesize dimethyl sulfoxide. Hydrogen sulfide gas from a factory with a flow rate of 500 m3/h and methanol gas with a flow rate of 1000 m3/h were reacted with catalyst γ-alumina to generate dimethyl sulfide, and then oxidized with nitrogen dioxide gas to generate dimethyl sulfoxide. The experimental data are as follows:

Table 1 Experimental data

When synthesizing dimethyl sulfoxide in the prior art, the yield of the synthesized dimethyl sulfoxide is 88.2%, wherein the purity of the dimethyl sulfoxide is about 80.5%, wherein the reaction temperature is about 110°C, and the reaction pressure is about 1.5MPa. As can be seen from Table 1, compared with the prior art, the yield and purity of dimethyl sulfoxide in each embodiment of the present invention are significantly improved, and the yield of dimethyl sulfoxide in Example 1 reaches 99.9%, The purity reaches 99.5%, and the reaction temperature and reaction pressure in Example 1 are significantly reduced, saving reaction energy consumption.

As can be seen from Table 1, Example 1 of the present invention is the best example. The system of this example uses the enhanced unit in conjunction with the oxidation reactor, and the product yield and purity of the obtained dimethyl sulfoxide are significantly higher than the purity of the dimethyl sulfoxide synthesized in the prior art; at the same time, the reaction temperature and the reaction pressure are significantly reduced, indicating that the enhanced unit and the oxidation reactor in Example 1 can achieve the best reaction effect. It can be seen that the preparation system of this example has low reaction energy consumption and good preparation effect.

Among them, the yield and purity of dimethyl sulfoxide in Comparative Example 1 are lower than those in Example 1. This is because Comparative Example 1 does not have an external strengthening unit, which cannot fully crush and disperse the reaction raw materials entering the oxidation reactor. It can be seen that Example 1 of the present invention improves the quality of dimethyl sulfoxide by setting an external strengthening unit outside the oxidation reaction tower.

In conclusion, compared with the prior art, the dimethyl sulfoxide synthesis system of the present invention has high raw material conversion rate and high product yield, and is worthy of wide promotion and application.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims (10)

A dimethyl sulfoxide synthesis system, characterized by comprising: a fixed bed reactor for synthesizing dimethyl sulfide and an oxidation reactor for synthesizing dimethyl sulfoxide; An external enhancement unit is arranged outside the oxidation reactor, and the external enhancement unit includes a first enhancement reactor and a second enhancement reactor. The first enhancement reactor is arranged above the second enhancement reactor, and the first enhancement reactor is connected to the discharge port at the bottom end of the fixed bed reactor. The second enhancement reactor is connected to a nitrogen dioxide or oxygen storage tank. A connecting pipe is arranged between the first enhancement reactor and the second enhancement reactor, and a static mixer is arranged in the connecting pipe. The dimethyl sulfoxide synthesis system according to claim 1 is characterized in that a built-in strengthening unit is arranged inside the oxidation reactor, and the built-in strengthening unit includes a third strengthening reactor arranged at the top of the oxidation reactor and a fourth strengthening reactor arranged below the third strengthening reactor, the third strengthening reactor is connected to the connecting pipe, and the fourth strengthening reactor is connected to the nitrogen dioxide or oxygen storage tank. The dimethyl sulfoxide synthesis system according to claim 2 is characterized in that the outlet of the third enhanced reactor is opposite to the outlet of the fourth enhanced reactor, the outlet of the third enhanced reactor is connected to a nozzle, and the outlet of the fourth enhanced reactor is provided with an agitator. The dimethyl sulfoxide synthesis system according to claim 2 is characterized in that a diversion component is arranged directly below the built-in intensification unit, and the diversion component includes a plurality of diversion plates arranged in sequence from top to bottom, and the interval distance between two adjacent diversion plates gradually decreases. The dimethyl sulfoxide synthesis system according to claim 4 is characterized in that a diversion hole is provided on the diversion plate, and the pore size of the diversion hole is 50-100 μm. The dimethyl sulfoxide synthesis system according to claim 1 is characterized in that the static mixer is a spiral metal tube, the spiral metal tube extends spirally along the longitudinal axis of the connecting pipe, and the spiral metal tube is adapted to the length of the connecting pipe. The synthesis system of dimethyl sulfoxide according to claim 1 is characterized in that the crude product outlet at the bottom of the oxidation reactor is connected to a vacuum distillation tower, and the side wall of the vacuum distillation tower is connected to the The third enhanced reactor is connected to recover unreacted raw materials. The dimethyl sulfoxide synthesis system according to claim 7, characterized in that it also includes a heating furnace, an azeotropic distillation tower, a neutralization evaporation reactor, an incinerator and a wastewater storage tank; The heating furnace is connected to the feed port of the fixed bed reactor, and the heating furnace is used to preheat methanol and hydrogen sulfide; The azeotropic distillation tower is disposed between the fixed bed reactor and the oxidation reactor, and the azeotropic distillation tower is used to purify the dimethyl sulfide coming out of the fixed bed reactor; The neutralization evaporation reactor is arranged between the oxidation reaction kettle and the azeotropic distillation tower to filter and remove impurities from dimethyl sulfoxide; The incinerator is respectively connected to the fixed bed reactor, the azeotropic distillation tower, the oxidation reactor, the neutralization evaporation reactor and the vacuum distillation tower; The wastewater storage tank is connected to the vacuum distillation tower to store wastewater. A method for synthesizing dimethyl sulfoxide using the dimethyl sulfoxide synthesis system according to any one of claims 1 to 8, characterized in that it comprises the following steps: Dimethyl sulfide is synthesized from methanol and hydrogen sulfide, and dimethyl sulfide is oxidized with nitrogen dioxide or oxygen to form dimethyl sulfoxide. The method for synthesizing dimethyl sulfoxide according to claim 9, characterized in that the reaction temperature during the oxidation reaction is 30-50° C. and the reaction pressure is 0.1-0.2 MPa.