A dimethyl sulfoxide synthesis system and synthesis method

Abstract

The application provides a synthesis system and method of dimethyl sulfoxide, comprising: a fixed bed reactor for synthesizing dimethyl sulfide and an oxidation reactor for synthesizing dimethyl sulfoxide; an external strengthening unit is arranged outside the oxidation reactor, the external strengthening unit comprises a first strengthening reactor and a second strengthening reactor, the first strengthening reactor is arranged above the second strengthening reactor, the first strengthening reactor is connected with a discharge port at the bottom end of the fixed bed reactor, the second strengthening reactor is connected with a nitrogen dioxide or oxygen storage tank, a communication pipeline is arranged between the first strengthening reactor and the second strengthening reactor, and a static mixer is arranged in the communication pipeline. The synthesis system of the application is based on the strengthening reaction technology, raw materials are broken and dispersed into micron-sized bubbles through the strengthening reactor, the mass transfer rate of the gas-phase raw materials to the reaction liquid and the macroscopic reaction rate are greatly improved, and the raw material conversion rate is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of dimethyl sulfoxide production, and particularly relates to a dimethyl sulfoxide synthesis system and a dimethyl sulfoxide synthesis method. BACKGROUND

[0002] Dimethyl sulfoxide is an extremely important organic solvent in the fields of medicine, chemical industry and material science. In industry, dimethyl sulfoxide is mainly synthesized by several methods: nitric acid method, hydrogen peroxide method, ozone method and nitrogen dioxide method. Among them, the nitrogen dioxide method has become the mainstream of 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 to generate dimethyl sulfide under the action of gamma-alumina, and then uses nitrogen dioxide or oxygen for oxidation reaction to produce crude dimethyl sulfoxide, and finally obtains refined dimethyl sulfoxide through vacuum distillation.

[0003] Although the liquid phase oxidation method has advantages in industrial production, there are still some problems and shortcomings. 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.

[0004] Therefore, the present application is proposed. SUMMARY

[0005] The first purpose of the present application is to provide a dimethyl sulfoxide synthesis system. The system is designed to solve the problems of low raw material conversion rate and difficult control of reaction conditions in the prior art. A reasonable process flow is designed, and based on the intensified reaction technology, the raw materials are broken and dispersed into micron-sized bubbles by the intensified reactor, which greatly improves the mass transfer rate of gas phase raw materials to the reaction liquid and the macroscopic reaction rate, and improves the raw material conversion rate.

[0006] The second purpose of the present application is to provide a method for synthesizing dimethyl sulfoxide by using the above-mentioned dimethyl sulfoxide synthesis system. The method is simple to operate, the operating conditions are more mild, the energy consumption is low, and the treatment effect is better than that of the prior art process.

[0007] In order to achieve the above-mentioned purposes of the present application, the following technical solutions are adopted:

[0008] The present application provides a dimethyl sulfoxide synthesis system, which comprises:

[0009] A fixed bed reaction kettle for synthesizing dimethyl sulfide and an oxidation reaction kettle for synthesizing dimethyl sulfoxide;

[0010] The external strengthening unit is provided outside the oxidation reaction kettle, and comprises a first strengthening reactor and a second strengthening reactor, the first strengthening reactor is arranged above the second strengthening reactor, the first strengthening reactor is connected with the discharge port at the bottom end of the fixed bed reaction kettle, the second strengthening reactor is connected with a nitrogen dioxide or oxygen storage tank, and a communication pipeline is arranged between the first strengthening reactor and the second strengthening reactor, and a static mixer is arranged in the communication pipeline.

[0011] In the prior art, the following problems exist in the synthesis of dimethyl sulfoxide: the incompleteness of the reaction in the synthesis of dimethyl sulfoxide by the traditional process, which leads to low conversion rate of raw materials, which means that in the oxidation stage of dimethyl sulfide, the raw materials are 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 reaction kettle are high, and the production capacity is also low.

[0012] To solve the above technical problems, the present application provides a synthesis system for dimethyl sulfoxide, which has a simple overall structure, and by arranging an external strengthening unit outside the oxidation reaction kettle, the raw materials entering the oxidation reaction kettle can be initially crushed and dispersed, the dimethyl sulfide liquid and nitrogen dioxide gas or oxygen can be crushed and dispersed into micron-sized micro-bubbles, the phase interface mass transfer area between the gas-liquid two phases is increased, and the conversion rate of raw materials is improved. In the external strengthening unit of the present application, the first strengthening reactor is arranged above the second strengthening reactor, which is arranged because the first strengthening reactor is connected with the discharge port at the bottom end of the fixed bed reaction kettle, the second strengthening reactor is connected with a nitrogen dioxide or oxygen storage tank, and a communication pipeline is arranged between the first strengthening reactor and the second strengthening reactor, which can provide a mixing place for the gas-liquid two phases, and the static mixer arranged in the communication pipeline can cooperate with the strengthening reactor to more uniformly mix the micro-bubbles discharged from the strengthening reactor, so that the micro-bubbles generated by the strengthening reactor can more effectively contact with the surrounding fluid, thereby improving the reaction efficiency.

[0013] Preferably, the inside of the oxidation reactor is provided with an internal intensifier unit, the internal intensifier unit comprises a third intensifier reactor arranged at the top end of the oxidation reactor and a fourth intensifier reactor arranged below the third intensifier reactor, the third intensifier reactor is connected with the communication pipeline, and the fourth intensifier reactor is connected with the nitrogen dioxide or oxygen tank. By arranging the internal intensifier unit, an intensification system is formed with the external intensifier unit arranged outside the oxidation reactor, the internal intensifier reactor can perform secondary crushing and dispersion on the mixed materials entering the oxidation reactor, the reaction raw materials are crushed into extremely small micron-sized bubbles, and the phase interface mass transfer area is further increased. Meanwhile, the fourth intensifier reactor of the present application is directly connected with the nitrogen dioxide or oxygen tank, and the purpose of such arrangement is to ensure that the carbon dioxide or oxygen in the oxidation reactor is excessive, so that the dimethyl sulfide is fully reacted.

[0014] Preferably, the outlet of the third intensifier reactor is opposite to the outlet of the fourth intensifier reactor, the outlet of the third intensifier reactor is connected with a nozzle, and the outlet of the fourth intensifier reactor is provided with a stirrer. By arranging the outlets of the third intensifier reactor and the fourth intensifier reactor of the internal intensifier unit to be opposite, a counterflow can be realized. By arranging the nozzle at the outlet of the third intensifier reactor, the flow rate of the micro-bubbles out of the third intensifier reactor can be accurately controlled, and the micro-bubbles can be uniformly sprayed in the oxidation reactor, so that the effect of efficient mixing is achieved. The outlet of the fourth intensifier reactor of the present application is provided with a stirrer, and the purpose of such arrangement is that the nitrogen dioxide gas or oxygen out of the fourth intensifier reactor needs to be fully reacted with the dimethyl sulfide liquid out of the third intensifier reactor, and the third intensifier reactor is arranged above. Therefore, by arranging the stirrer, the gas out of the fourth intensifier reactor can be uniformly diffused, and the dimethyl sulfide liquid out of the third intensifier reactor can be mixed with the gas out of the fourth intensifier reactor by cooperation of the third intensifier reactor, so that the conversion rate between raw materials is improved.

[0015] Preferably, a flow splitting assembly is arranged directly below the internal intensifier unit, the flow splitting assembly comprises a plurality of flow splitting plates arranged in sequence from top to bottom, and the interval distance between adjacent two flow splitting plates gradually decreases. The flow splitting assembly of the present application is arranged below the internal intensifier unit, and the advantage of such arrangement is that the reaction time between the micro-bubble mixed materials out of the internal intensifier reactor can be prolonged. The interval distance between adjacent two flow splitting plates gradually decreases, so that the degree of turbulence in the fluid can be enhanced, the mixing effect can be improved, the speed of the fluid can be effectively controlled, the energy loss caused by fluid friction or turbulence can be reduced, and the energy efficiency of the overall system can be improved.

[0016] Preferably, the shunt plate is provided with a shunt hole, and the shunt hole has a hole diameter of 50-100 microns. The shunt plate of the present application has a micron-level hole diameter, which can filter out large bubbles, thereby improving the overall reaction efficiency.

[0017] Preferably, the static mixer is a spiral metal pipe that spirally extends along the longitudinal axis of the communication pipeline, and the spiral metal pipe is adapted to the length of the communication pipeline.

[0018] Preferably, the surface of the spiral metal pipe is provided with through holes.

[0019] By selecting a spiral metal pipe, the reaction time can be prolonged, the fluid can be guided to flow in a more effective manner, the turbulent flow and fluid resistance can be reduced, and the heat exchange efficiency can be improved. The through holes can reduce the resistance of the fluid in the pipeline.

[0020] Preferably, the bottom end of the oxidation reaction kettle is connected with a vacuum rectifying tower, and the side wall of the vacuum rectifying tower is connected with the third intensifier reactor for recycling unreacted raw materials. By providing the vacuum rectifying tower, the unreacted raw materials can be returned to the oxidation reaction kettle for further reaction, thereby improving the conversion rate of the raw materials.

[0021] In the present application, by providing the fixed bed reactor and the oxidation reaction kettle, a stable reaction environment can be provided for synthesizing dimethyl sulfide and converting dimethyl sulfide into dimethyl sulfoxide. Meanwhile, the external intensifier unit is arranged outside the oxidation reaction kettle, which can convert the gas-liquid two-phase raw materials into micron-level bubbles through the cooperation of the first intensifier reactor and the second intensifier reactor, thereby improving the phase interface mass transfer area of the gas-liquid two-phase. The internal intensifier unit is used in cooperation with the external intensifier unit to form an intensification system, which can further break and disperse the mixed materials entering the oxidation reaction kettle, thereby improving the reaction efficiency and the selectivity of the raw materials.

[0022] The present application is provided with a communication pipeline in the external intensifier unit, and a static mixer is arranged inside the communication pipeline. By providing the communication pipeline, the uniform mixing of the materials can be promoted, and the first intensifier reactor and the second intensifier reactor can be supported. Meanwhile, the two ends of the static mixer are connected with the first intensifier reactor and the second intensifier reactor, respectively, which can uniformly mix the reaction raw materials coming out of the intensifier reactor, filter out large bubbles through the through holes, and improve the reaction rate.

[0023] The application can timely stir and mix the micro-bubbles from the intensification reactor by connecting the nozzle and the stirrer at the end of the two intensification reactors with the intensification unit, further improves the reaction rate and the conversion rate of raw materials; meanwhile, the shunt assembly is arranged below the intensification reactor, which is used in cooperation with the intensification unit, can filter the mixed materials from the intensification unit, ensure that only the micron-level micro-bubbles flow into the bottom end of the oxidation reactor, and prolong the reaction time and improve the conversion rate of raw materials.

[0024] Those skilled in the art can understand that the intensification reactor used in the application has been embodied in the prior patents of the inventor, such as the patents with the application numbers CN201610641119.6, CN201610641251.7, CN201710766435.0, CN106187660, CN105903425A, CN109437390A, CN205833127U and CN207581700U. The prior patent CN201610641119.6 introduces the specific product structure and working principle of the micron-bubble generator (i.e. the intensification reactor) in detail, which records in the application file that "the micron-bubble generator includes a body and a secondary breaking piece, the body has a cavity, the body is provided with an inlet communicating with the cavity, the opposite first end and the second end of the cavity are open, wherein the cross-sectional area of the cavity decreases from the middle part of the cavity to the first end and the second end of the cavity; the secondary breaking piece is arranged at least one of the first end and the second end of the cavity, a part of the secondary breaking piece is arranged in the cavity, and an annular channel is formed between the secondary breaking piece and the open through hole at both ends of the cavity. The micron-bubble generator further includes a gas inlet pipe and a liquid inlet pipe." From the specific structure disclosed in the application file, the specific working principle can be known: the liquid enters the micron-bubble generator tangentially through the liquid inlet pipe, rotates at a high speed and cuts the gas, so that the gas bubbles are broken into micron-level micro-bubbles, thereby improving the mass transfer area between the liquid phase and the gas phase, and the micron-bubble generator in the patent belongs to a pneumatic intensification reactor.

[0025] In addition, the prior patent 201610641251.7 discloses that a primary bubble breaker has a circulating liquid inlet, a circulating gas inlet and a gas-liquid mixture outlet, and a secondary bubble breaker is connected with the feed inlet and the gas-liquid mixture outlet, which indicates that the bubble breaker needs gas-liquid mixture to enter. In addition, from the subsequent drawings, it can be seen that the primary bubble breaker mainly uses circulating liquid as power, so the primary bubble breaker actually belongs to a liquid-driven enhanced reactor. The secondary bubble breaker actually belongs to a gas-liquid linkage enhanced reactor. In fact, whether it is a liquid-driven enhanced reactor or a gas-liquid linkage enhanced reactor, it belongs to a specific form of an enhanced reactor. However, the enhanced reactor adopted in the present application is not limited to the above-mentioned forms. The specific structure of the bubble breaker disclosed in the prior patent is only one of the forms that can be adopted by the enhanced reactor of the present application.

[0026] In addition, the prior patent 201710766435.0 discloses that the principle of the bubble breaker is high-speed jet flow to achieve mutual collision of gas phases, and it can be used in a micro-interface enhanced reactor to verify the relevance between the bubble breaker and the micro-interface generator. In addition, the prior patent CN106187660 also discloses the specific structure of the bubble breaker, specifically see paragraphs

[0031] -

[0041] in the specification and the drawing part, which has 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 entering from the top provides a suction power, so as to achieve the effect of crushing into ultra-fine bubbles. As can be seen from the drawing, the bubble breaker has a conical structure, and the diameter of the upper part is larger than that of the lower part, so that the liquid phase can provide better suction power.

[0027] In the early stage of the prior patent application, the enhanced reactor was just developed, so it was named as a micron bubble generator (CN201610641119.6) and a bubble breaker (201710766435.0) in the early stage. With continuous technical improvement, it was renamed as an enhanced reactor in the later stage. The enhanced reactor in the present application is equivalent to the previous micron bubble generator and bubble breaker, only the name is different. In summary, the enhanced reactor of the present application belongs to the prior art.

[0028] Preferably, the dimethyl sulfoxide synthesis system of the present application further comprises a heating furnace, a azeotropic distillation column, a neutralization evaporation reactor, an incinerator and a wastewater storage tank;

[0029] The heating furnace is connected with the feed inlet of the fixed bed reactor, and the heating furnace is used to preheat the methanol and hydrogen sulfide;

[0030] The azeotropic rectification tower is arranged between the fixed bed reactor and the oxidation reactor, and is used for refining dimethyl sulfide from the fixed bed reactor;

[0031] The neutralization evaporation reactor is arranged between the oxidation reactor and the azeotropic rectification tower, and is used for filtering impurities of dimethyl sulfoxide;

[0032] The incinerator is connected with the fixed bed reactor, the azeotropic rectification tower, the oxidation reactor, the neutralization evaporation reactor and the vacuum rectification tower, respectively.

[0033] The wastewater storage tank is connected with the vacuum rectification tower, and is used for storing wastewater.

[0034] By arranging the heating furnace, the azeotropic rectification tower, the neutralization evaporation reactor, the incinerator and the wastewater storage tank, the synthesis system of the application is more perfect, and the continuity and efficiency of the production process are ensured by the comprehensive system design, and the environmental pollution is reduced.

[0035] In addition, the application further provides a synthesis method of dimethyl sulfoxide.

[0036] Preferably, the synthesis method of dimethyl sulfoxide comprises the following steps: synthesizing dimethyl sulfide from methanol and hydrogen sulfide, and generating dimethyl sulfoxide by oxidizing dimethyl sulfide with nitrogen dioxide or oxygen.

[0037] Preferably, the reaction temperature of the oxidation reaction is 30-50 DEG C, and the reaction pressure is 0.1-0.2 MPa.

[0038] The synthesis method of the application is simple in operation, the operation condition is more moderate, and the product quality is higher.

[0039] Compared with the prior art, the application has the beneficial effects that:

[0040] (1) The application sets an external intensifier unit outside the oxidation reactor, breaks and disperses the raw materials entering the oxidation reactor, improves the mass transfer effect between the reaction materials, and improves the reaction efficiency.

[0041] (2) The application sets an internal intensifier unit in the oxidation reactor, and cooperates with the shunt component, which can effectively break and disperse the reaction raw materials, prolong the reaction time, and improve the conversion rate of the raw materials.

[0042] (3) The application is connected with an azeotropic distillation device and a vacuum rectification tower after the fixed bed reactor and the oxidation reactor, respectively, which can purify and refine the intermediate product dimethyl sulfide and the final product dimethyl sulfoxide, respectively, and improve the product quality. BRIEF DESCRIPTION OF DRAWINGS

[0043] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The detailed description is made with reference to the accompanying drawings.

[0044] Fig. 1 A flow schematic diagram of a dimethyl sulfoxide synthesis system provided for embodiment 1 of the present application;

[0045] Fig. 2 A partial enlarged view of a static mixer provided for embodiment 1 of the present application;

[0046] Fig. 3 A structural schematic view of a flow distribution plate provided for embodiment 1 of the present application.

[0047] Wherein:

[0048] 1 - heating furnace; 2 - fixed bed reactor;

[0049] 3 - azeotropic distillation column; 4 - oxidation reactor;

[0050] 401 - flow distribution assembly; 4011 - flow distribution plate;

[0051] 4012 - flow distribution hole; 5 - neutralization evaporation reactor;

[0052] 6 - vacuum distillation column; 7 - wastewater storage tank;

[0053] 8 - incinerator; 9 - external intensifier unit;

[0054] 901 - first intensifier reactor; 902 - second intensifier reactor;

[0055] 903 - communication pipeline; 904 - static mixer;

[0056] 9041 - spiral metal pipe; 9042 - through hole;

[0057] 10 - built-in intensifier unit; 101 - third intensifier reactor;

[0058] 102 - fourth intensifier reactor; 103 - nozzle;

[0059] 104 - agitator; 11 - hydrogen sulfide storage tank;

[0060] 12 - methanol storage tank; 13 - nitrogen dioxide or oxygen storage tank. DETAILED DESCRIPTION

[0061] The technical solutions of the present application will be described clearly and completely in the following description in combination with the drawings and specific embodiments, but those skilled in the art will understand that the following described embodiments are part of the embodiments of the present application, not all the embodiments, and are only used to illustrate the present application, and should not be regarded as limiting the scope of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative efforts fall within the scope of protection of the present application. The specific conditions not mentioned in the embodiments are carried out according to the conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments used are not marked with the manufacturer, which are conventional products that can be purchased on the market.

[0062] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0063] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0064] In order to more clearly describe the technical solutions in the present application, the following will be described in the form of specific embodiments.

[0065] Example 1

[0066] Reference Figs. 1-3As shown, the synthesis system of dimethyl sulfoxide in the embodiment of the present application comprises a heating furnace 1, a fixed bed reactor 2 for synthesizing dimethyl sulfide, an azeotropic rectification tower 3 for refining crude dimethyl sulfide, an oxidation reactor 4 for synthesizing dimethyl sulfoxide, a neutralization and evaporation reactor 5 and a vacuum rectification tower 6 connected in sequence; the heating furnace 1 is connected with the feed inlet of the fixed bed reactor 2; the azeotropic rectification tower 3 is connected with the discharge port at the bottom end of the fixed bed reactor 2; the azeotropic rectification tower 3 is connected with the oxidation reactor 4; wherein, the oxidation reactor 4 is externally provided with an external strengthening unit 9, the external strengthening unit 9 comprises a first strengthening reactor 901 and a second strengthening reactor 902; the first strengthening reactor 901 is connected with the bottom end of the azeotropic rectification tower 3, the second strengthening reactor 902 is connected with a nitrogen dioxide or oxygen storage tank 13, and a communication pipeline 903 is arranged between the first strengthening reactor 901 and the second strengthening reactor 902, and a static mixer 904 is arranged in the communication pipeline 903.

[0067] Referring to Fig. 2 As shown, the static mixer 904 in the present application is a spiral metal pipe 9041, which spirally extends along the longitudinal axis of the communication pipeline 903, and the length of the spiral metal pipe 9041 is matched with the length of the communication pipeline 903, and specifically, the surface of the spiral metal pipe 9041 is provided with a plurality of through holes 9042.

[0068] In the embodiment, the oxidation reactor 4 is internally provided with an internal strengthening unit 10, the internal strengthening unit 10 comprises a third strengthening reactor 101 arranged at the top end of the oxidation reactor 4 and a fourth strengthening reactor 102 arranged below the third strengthening reactor 101, the third strengthening reactor 101 is connected with the outlet of the communication pipeline 903, and the fourth strengthening reactor 102 is connected with the nitrogen dioxide or oxygen storage tank 13. Specifically, the outlet of the third strengthening reactor 101 is opposite to the outlet of the fourth strengthening reactor 102, the outlet of the third strengthening reactor 101 is connected with a nozzle 103, and the outlet of the fourth strengthening reactor 102 is provided with a stirrer 104. The side wall of the vacuum rectification tower 6 of the present application is connected with the third strengthening reactor 101 for recycling unreacted raw materials.

[0069] The internal strengthening unit 10 of the present application is provided with a shunt assembly 401 below, the shunt assembly 401 comprises a plurality of shunt plates 4011 arranged in sequence from top to bottom, and the interval distance between adjacent two shunt plates 4011 gradually decreases. Specifically, referring to Fig. 3 As shown, the shunt plate 4011 is provided with a shunt hole 4012, and the hole diameter of the shunt hole 4012 is 50-100 μm.

[0070] The dimethyl sulfoxide synthesis system of the application further comprises a waste water storage tank 7 and a waste incinerator 8; the waste incinerator 8 is connected with the fixed bed reactor 2, the azeotropic distillation column 3, the oxidation reactor 4, the neutralization and evaporation reactor 5 and the top of the vacuum distillation column 6 respectively to remove the waste gas generated in the reaction; and the waste water storage tank 7 is connected with the vacuum distillation column 6 to store the waste water.

[0071] The dimethyl sulfoxide synthesis system of the application comprises the following process flow in actual application:

[0072] The hydrogen sulfide gas and the methanol gas from the upstream hydrogen sulfide storage tank 11 and the methanol storage tank 12 are preheated by the heating furnace 1, then enter 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 column 3 through the material outlet at the bottom of the fixed bed reactor 2, and the water in the crude dimethyl sulfide is removed by azeotropic distillation; the purified dimethyl sulfide enters the external intensifier unit 9, and the nitrogen dioxide gas or oxygen in the nitrogen dioxide or oxygen storage tank 13 enters the external intensifier unit 9 to be initially broken, dispersed and mixed; then the mixed material enters the oxidation reactor 4 to generate crude dimethyl sulfoxide; then the crude dimethyl sulfoxide enters the neutralization and evaporation reactor 5 to be neutralized, evaporated, concentrated and desalted; the waste gas generated in the reaction is treated at high temperature by the waste incinerator 8, and the waste water generated in the reaction enters the waste water storage tank 7 and is transported to the subsequent waste water treatment unit.

[0073] Example 2

[0074] The difference between this example and example 1 is that the static mixer is a straight-through metal pipe.

[0075] Example 3

[0076] The difference between this example and example 1 is that the distance between each baffle is equal.

[0077] Example 4

[0078] The difference between this example and example 1 is that the aperture of the shunt hole is 10 mm.

[0079] Comparative Example 1

[0080] The difference between this example and example 1 is that the external intensifier unit is not provided.

[0081] Comparative Example 2

[0082] The difference between this example and example 1 is that the internal intensifier unit is not provided.

[0083] Comparative Example 3

[0084] The difference between this example and example 1 is only that the shunt assembly is not provided.

[0085] Comparative example 4

[0086] This example uses prior art, directly oxidizing hydrogen sulfide gas and dimethyl sulfide generated by methanol gas with nitrogen dioxide to generate dimethyl sulfoxide.

[0087] Experimental example 1

[0088] The system of examples 1-4 and comparative examples 1-3 is used to synthesize dimethyl sulfoxide, respectively, hydrogen sulfide gas from a factory, flow rate 500 m3 / h; methanol gas, flow rate 1000 m3 / h, is reacted with catalyst γ-alumina to generate dimethyl sulfide, and then oxidized with nitrogen dioxide gas to generate dimethyl sulfoxide, and the experimental data is as follows:

[0089] Table 1 experimental data

[0090]

[0091] When synthesizing dimethyl sulfoxide in the prior art, the yield of the synthesized dimethyl sulfoxide is 88.2%, and the purity of the dimethyl sulfoxide is about 80.5%, wherein the reaction temperature is about 110℃, and the reaction pressure is about 1.5 MPa. As can be seen from table 1, compared with the prior art, the yield and purity of dimethyl sulfoxide of each embodiment of the present application are significantly improved, and the yield of dimethyl sulfoxide of example 1 reaches 99.9%, and the purity reaches 99.5%, and the reaction temperature and reaction pressure in example 1 are significantly reduced, saving reaction energy consumption.

[0092] As can be seen from table 1, example 1 of the present application is the optimal embodiment, the system of this embodiment uses the intensifier set and the oxidation reaction kettle in cooperation, and the product yield and purity of the dimethyl sulfoxide obtained are significantly higher than those of the dimethyl sulfoxide synthesized in the prior art; at the same time, the reaction temperature and reaction pressure are significantly reduced, indicating that the use of the intensifier set and the oxidation reaction kettle in cooperation in example 1 can achieve the optimal reaction effect, and it can be seen that the preparation system of this embodiment has low reaction energy consumption and good preparation effect.

[0093] Among them, the yield and purity of dimethyl sulfoxide of comparative example 1 are lower than those of example 1, because comparative example 1 does not set an external intensifier set, and it cannot fully crush and disperse the reaction raw materials entering the oxidation reaction kettle, and it can be seen that the quality of dimethyl sulfoxide is improved by setting an external intensifier set outside the oxidation reaction tower in example 1.

[0094] In summary, compared with the prior art, the synthesis system of dimethyl sulfoxide of the present application has high raw material conversion rate and high product yield, and is worthy of wide application.

[0095] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit the present application; although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions recorded in the above embodiments can still be modified, or some or all of the technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A system for the synthesis of dimethyl sulfoxide, characterized in that, The application relates to a fixed bed reactor for synthesizing dimethyl sulfide and an oxidation reactor for synthesizing dimethyl sulfoxide. An external intensification unit is arranged outside the oxidation reactor, the external intensification unit comprises a first intensification reactor and a second intensification reactor, the first intensification reactor is arranged above the second intensification reactor, the first intensification reactor is connected with a discharge port at the bottom end of the fixed bed reactor, the second intensification reactor is connected with a nitrogen dioxide or oxygen storage tank, a communication pipeline is arranged between the first intensification reactor and the second intensification reactor, and a static mixer is arranged in the communication pipeline. An internal intensification unit is arranged inside the oxidation reactor, the internal intensification unit comprises a third intensification reactor arranged at the top end of the oxidation reactor and a fourth intensification reactor arranged below the third intensification reactor, the third intensification reactor is connected with the communication pipeline, and the fourth intensification reactor is connected with the nitrogen dioxide or oxygen storage tank. A flow splitting assembly is arranged directly below the internal intensification unit, the flow splitting assembly comprises a plurality of flow splitting plates arranged in sequence from top to bottom, and the spacing between adjacent two flow splitting plates gradually decreases. The outlet of the third intensification reactor is opposite to the outlet of the fourth intensification reactor, a nozzle is connected with the outlet of the third intensification reactor, and a stirrer is arranged at the outlet of the fourth intensification reactor.

2. The synthesis system of dimethyl sulfoxide according to claim 1, characterized by, A flow splitting hole is arranged on the flow splitting plate, and the diameter of the flow splitting hole is 50-100 mu m.

3. The dimethyl sulfoxide synthesis system of claim 1, wherein, The static mixer is a spiral metal pipe, the spiral metal pipe spirally extends along the longitudinal axis of the communication pipeline, and the length of the spiral metal pipe is matched with the length of the communication pipeline.

4. The dimethyl sulfoxide synthesis system of claim 1, wherein, A vacuum rectifying tower is connected with the coarse product outlet at the bottom end of the oxidation reactor, and the side wall of the vacuum rectifying tower is connected with the third intensification reactor to recover unreacted raw materials.

5. The dimethyl sulfoxide synthesis system of claim 1, wherein, A heating furnace, a azeotropic rectifying tower, a neutralization evaporation reactor, an incinerator and a wastewater storage tank are further included.

6. The synthesis system of dimethyl sulfoxide according to claim 5, wherein, The heating furnace is connected with the feed inlet of the fixed bed reactor, and the heating furnace is used for preheating methanol and hydrogen sulfide. The azeotropic rectifying tower is arranged between the fixed bed reactor and the oxidation reactor, and the azeotropic rectifying tower is used for refining dimethyl sulfide discharged from the fixed bed reactor. The neutralization evaporation reactor is arranged between the oxidation reactor and the azeotropic rectifying tower, and is used for filtering and removing impurities from dimethyl sulfoxide. The incinerator is connected with the fixed bed reactor, the azeotropic rectifying tower, the oxidation reactor, the neutralization evaporation reactor and the vacuum rectifying tower respectively. The wastewater storage tank is connected with the vacuum rectifying tower to store wastewater. The application further relates to a method for synthesizing dimethyl sulfoxide.

7. A method for synthesizing dimethyl sulfoxide by using the system for synthesizing dimethyl sulfoxide according to any one of claims 1 to 6, characterized by, The reaction temperature of the oxidation reaction is 30-50 DEG C, and the reaction pressure is 0.1-0.2 MPa. ​ 8. The method for synthesizing dimethyl sulfoxide according to claim 7, characterized in that, ​

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