A catalyst for producing dimethyl sulfoxide and a method for producing dimethyl sulfoxide

Abstract

The application provides application of a shaped titanium silicate molecular sieve in preparation of dimethyl sulfoxide; the content of aluminum oxide in the shaped titanium silicate molecular sieve is 1wt%-2wt%; the content of silicon oxide in the shaped titanium silicate molecular sieve is 90wt%-95wt%; and the content of titanium oxide in the shaped titanium silicate molecular sieve is 4wt%-5wt%. The application also provides a corresponding preparation method of dimethyl sulfoxide, which uses a shaped small-grain titanium silicate molecular sieve as a catalyst and self-product dimethyl sulfoxide as a solvent to solve the solubility problem of raw materials, realizes the reaction of dimethyl sulfide and hydrogen peroxide to produce dimethyl sulfoxide in a pipe reactor at 25-45 DEG C under relatively mild conditions, and the selectivity of dimethyl sulfoxide is more than 99%.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of catalysts for preparing dimethyl sulfoxide, and relates to application of a shaped titanium-silicon molecular sieve in preparation of dimethyl sulfoxide and a preparation method of dimethyl sulfoxide, in particular to a catalyst for producing dimethyl sulfoxide and a preparation method of dimethyl sulfoxide. BACKGROUND

[0002] Dimethyl sulfoxide is a kind of sulfur-containing aprotic polar solvent, which is called "universal solvent". In addition, it has the functions of analgesia, anti-inflammation, sedation, promoting wound healing and strong penetration to the body, so it is also called "universal medicine". It is widely used in the fields of medicine and medical treatment, petrochemical industry, organic synthesis, synthetic fibers, pesticides, coatings, dyes, synthetic resins, gas separation, recovery of by-products of coking, wet smelting of rare metals, electronic industry and preparation of antifreeze, etc.

[0003] The production process of dimethyl sulfoxide generally adopts dimethyl sulfide oxidation method, and the oxidation processes mainly include nitric acid oxidation method, ozone method, nitrogen dioxide method and hydrogen peroxide method. However, the nitric acid oxidation method has serious equipment corrosion and consumes a large amount of acid and alkali; the ozone oxidation method has too low conversion rate; the nitrogen dioxide liquid phase oxidation method is relatively dangerous and produces a large amount of waste salt; and the hydrogen peroxide method is relatively green and environmentally friendly, but the cost is slightly high and the selectivity needs to be improved.

[0004] Therefore, how to find a more suitable dimethyl sulfoxide preparation method to solve the above problems existing in the current dimethyl sulfoxide production process has become one of the problems to be solved by many front-line researchers in the industry. SUMMARY

[0005] Therefore, the technical problem to be solved by the present application is to provide application of a shaped titanium-silicon molecular sieve in preparation of dimethyl sulfoxide and a preparation method of dimethyl sulfoxide, in particular a preparation method of dimethyl sulfoxide. The present application uses a shaped small-grained titanium-silicon molecular sieve as a catalyst, uses self-produced dimethyl sulfoxide as a solvent, solves the solubility problem of raw materials, realizes production of dimethyl sulfoxide from dimethyl sulfide and hydrogen peroxide under relatively mild conditions. The preparation method provided by the present application has the advantages of simple process, mild conditions, strong controllability, lower cost, more suitable for large-scale promotion and application, and wide application prospect.

[0006] The present application provides application of a shaped titanium-silicon molecular sieve in preparation of dimethyl sulfoxide.

[0007] The content of alumina in the shaped titanium-silicon molecular sieve is 1wt%-2wt%;

[0008] The content of silicon oxide in the shaped titanium-silicon molecular sieve is 90wt%-95wt%.

[0009] The content of titanium oxide in the shaped titanium silicalite molecular sieve is 4wt% to 5wt%.

[0010] Preferably, the application is specifically the application as a catalyst.

[0011] The shaped titanium silicalite molecular sieve is specifically a titanium silicalite molecular sieve after shaping and calcination.

[0012] The shape of the shaped titanium silicalite molecular sieve includes one or more of a strip, a spherical ball, and a cylindrical shape.

[0013] Preferably, the transverse dimension of the shaped titanium silicalite molecular sieve is 4 to 5 mm.

[0014] The longitudinal dimension of the shaped titanium silicalite molecular sieve is 4 to 5 mm.

[0015] The shaped titanium silicalite molecular sieve contains small crystal titanium silicalite molecular sieve.

[0016] The size of the small crystal titanium silicalite molecular sieve is 150 to 450 nm.

[0017] Preferably, the specific surface area of the shaped titanium silicalite molecular sieve is 150 to 300 m 2 / g.

[0018] The pore volume of the shaped titanium silicalite molecular sieve is 0.35 to 0.50 ml / g.

[0019] The average pore size of the shaped titanium silicalite molecular sieve is 7 to 10 nm.

[0020] Preferably, the preparation process of the shaped titanium silicalite molecular sieve includes the following steps:

[0021] The titanium silicalite molecular sieve, the aluminum source, the silicon source, and the binder are uniformly mixed, shaped through a mold, and then calcined to obtain the shaped titanium silicalite molecular sieve.

[0022] The Si / Ti ratio of the titanium silicalite molecular sieve is 20 to 30.

[0023] The calcination temperature is 450 to 600°C.

[0024] The binder includes one or more of silica sol, aluminum sol, carboxymethyl cellulose, polyvinylpyrrolidone, and nitric acid.

[0025] Preferably, the raw material for preparing dimethyl sulfoxide includes dimethyl sulfide and hydrogen peroxide.

[0026] The raw material for preparing dimethyl sulfoxide also includes a dimethyl sulfoxide solvent.

[0027] The feed air speed of the raw material is 2-12h -1 .

[0028] The application provides a preparation method of dimethyl sulfoxide, comprising the following steps:

[0029] 1) mixing dimethyl sulfide and dimethyl sulfoxide solvent to obtain a mixed solution;

[0030] 2) adding hydrogen peroxide into the mixed solution obtained in the above step to perform mixing reaction, to obtain a mixed material;

[0031] 3) passing the mixed material obtained in the above step into a reaction device, and performing reaction again under the action of a shaped titanium-silicon molecular sieve catalyst, to obtain dimethyl sulfoxide;

[0032] The shaped titanium-silicon molecular sieve is the shaped titanium-silicon molecular sieve in the application of any one of the above technical solutions.

[0033] Preferably, the concentration of the hydrogen peroxide is 27%-30%;

[0034] The adding mode comprises dropwise adding;

[0035] In the step 2), the reaction temperature is controlled to be 25-30 DEG C;

[0036] In the step 2), the mass content of the hydrogen peroxide in the mixed material is 0.65%-1.70%.

[0037] Preferably, the molar ratio of hydrogen peroxide to dimethyl sulfide in the hydrogen peroxide is (0.8-1.1):1;

[0038] The mass ratio of the total mass of the hydrogen peroxide and dimethyl sulfide to the mass of dimethyl sulfoxide is 1:(0.5-3);

[0039] The passing in is specifically passing in the mixed material in a continuous stirring process into the reaction device;

[0040] The stirring speed is 200-1000r / min;

[0041] The feed air speed of the raw material is 2-12h -1 .

[0042] Preferably, the reaction device comprises a fixed bed reactor or a tubular reactor;

[0043] The temperature of the reaction again is 25-45 DEG C;

[0044] The pressure of the reaction again is normal pressure;

[0045] In the preparation method, the selectivity of the prepared dimethyl sulfoxide is greater than or equal to 99%.

[0046] The application provides application of a shaped titanium silicalite molecular sieve in preparation of dimethyl sulfoxide; the content of alumina in the shaped titanium silicalite molecular sieve is 1wt%-2wt%; the content of silicon oxide in the shaped titanium silicalite molecular sieve is 90wt%-95wt%; and the content of titanium oxide in the shaped titanium silicalite molecular sieve is 4wt%-5wt%. Compared with the prior art, the shaped titanium silicalite molecular sieve for dimethyl sulfoxide is specially designed, the material has specific composition and structure, small-grained titanium silicalite molecular sieve is used as a core component of a catalyst, a certain amount of alumina and silicon oxide is doped to adjust the activity of the catalyst, the catalyst is used as a catalyst for preparing dimethyl sulfoxide, the selectivity of dimethyl sulfoxide preparation is better improved, and the process route is realized under relatively mild conditions without using alkaline substances.

[0047] The application also provides a preparation method of dimethyl sulfoxide. Small-grained titanium silicalite molecular sieve is used as a core component of a catalyst, a certain amount of alumina and silicon oxide is doped to adjust the activity of the catalyst, self-generated dimethyl sulfoxide is used as a solvent to improve the solubility of raw materials, a tubular reactor is used, and the reaction of dimethyl sulfide and hydrogen peroxide is realized under relatively mild conditions. The selectivity of dimethyl sulfoxide can be more than 99%, the problems that the prior art uses low-boiling-point solvents such as methanol (boiling point 64.7℃), acetone (boiling point 56.5℃) and isopropyl alcohol (boiling point 82.45℃), and the solvents need to be distilled out for reuse in the product separation process, and hydrogen peroxide starts to decompose at 60℃, and the risk problem that the explosive mixture is generated by the decomposition of hydrogen peroxide are solved. Moreover, the application can control the mildness of the operation condition by adjusting the activity of the catalyst, and the problem of intense heat release in the oxidation reaction is solved.

[0048] The application is verified by a large number of experiments, the action mechanism is analyzed in depth, the index of the catalyst used in the reaction system of dimethyl sulfide and hydrogen peroxide and the preparation method thereof are determined, small-grained shaped titanium silicalite molecular sieve is used as the catalyst, the reaction is carried out at 25-45℃ in a tubular reactor, self-generated dimethyl sulfoxide is used as a solvent to solve the solubility problem of raw materials, the high space velocity of dimethyl sulfide is combined, the reaction of dimethyl sulfide and hydrogen peroxide is realized under relatively mild conditions without using alkaline substances, dimethyl sulfoxide is produced, and the selectivity of dimethyl sulfoxide is more than 99%. The preparation method provided by the application has the advantages of simple process, mild condition, strong controllability, lower cost, more suitable for large-scale promotion and application, and wide application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0049] Figure 1 The electron microscope graph of the small-grained titanium silicalite molecular sieve prepared by the application. DETAILED DESCRIPTION

[0050] For a further understanding of the present application, preferred embodiments thereof will be described in conjunction with examples, it should be understood, however, that these are designed to further illustrate the features and advantages of the present application, and are not intended to limit the scope of the claims. Those skilled in the art can make appropriate modifications to the process parameters based on the content herein. It is particularly pointed out that all such similar substitutes and modifications apparent from the content herein are intended to be within the scope of the present application. The methods and applications of the present application have been described by preferred embodiments, and those skilled in the art can obviously make modifications or appropriate changes and combinations to the methods and applications described herein without departing from the content, spirit and scope of the present application, to realize and apply the present application.

[0051] All raw materials of the present application are not particularly limited in source, and can be purchased on the market or prepared according to conventional methods well known to those skilled in the art.

[0052] All raw materials of the present application are not particularly limited in purity, and the present application preferably uses analytically pure or meets the purity standards in the field of dimethyl sulfoxide preparation.

[0053] All raw materials of the present application are of conventional source and abbreviation in the art, and are clear and explicit in the field of their related use. Those skilled in the art can purchase or prepare them by conventional methods according to the abbreviation and corresponding use.

[0054] The present application provides the use of a shaped titanium silicalite molecular sieve in the preparation of dimethyl sulfoxide.

[0055] In the present application, the content of alumina in the shaped titanium silicalite molecular sieve is 1wt%-2wt%, or 1.2wt%-1.8wt%, or 1.4wt%-1.6wt%.

[0056] In the present application, the content of silicon oxide in the shaped titanium silicalite molecular sieve is 90wt%-95wt%, or 91wt%-94wt%, or 92wt%-93wt%.

[0057] In the present application, the content of titanium oxide in the shaped titanium silicalite molecular sieve is 4wt%-5wt%, or 4.2wt%-4.8wt%, or 4.4wt%-4.6wt%.

[0058] In the present application, the application is particularly preferably the use as a catalyst.

[0059] In the present application, the shaped titanium silicalite molecular sieve is particularly preferably a titanium silicalite molecular sieve after shaping and calcination.

[0060] In the present application, the shape of the shaped titanium silicalite molecular sieve preferably comprises one or more of a strip shape, a spherical shape and a cylindrical shape, more preferably a strip shape, a spherical shape or a cylindrical shape.

[0061] In the present application, the transverse dimension of the shaped titanium silicalite molecular sieve is preferably 4-5 mm.

[0062] In the present application, the longitudinal dimension of the shaped titanium silicalite molecular sieve is preferably 4-5 mm.

[0063] In the present application, the shaped titanium silicalite molecular sieve preferably contains small crystal titanium silicalite molecular sieve.

[0064] In the present application, the size of the small crystal titanium silicalite molecular sieve is preferably 150-450 nm, more preferably 200-400 nm, more preferably 250-350 nm.

[0065] In the present application, the specific surface area of the shaped titanium silicalite molecular sieve is preferably 150-300 m 2 / g, more preferably 180-300 m 2 / g, more preferably 210-280 m 2 / g.

[0066] In the present application, the pore volume of the shaped titanium silicalite molecular sieve is preferably 0.35-0.50 ml / g, more preferably 0.38-0.50 ml / g, more preferably 0.41-0.48 ml / g.

[0067] In the present application, the average pore diameter of the shaped titanium silicalite molecular sieve is preferably 7-10 nm, more preferably 7.5-9.5 nm, more preferably 8-9 nm.

[0068] In the present application, the preparation process of the shaped titanium silicalite molecular sieve preferably comprises the following steps:

[0069] The titanium silicalite molecular sieve, the aluminum source, the silicon source and the binder are mixed uniformly, shaped through a mold, and then calcined to obtain the shaped titanium silicalite molecular sieve.

[0070] In the present application, the Si / Ti ratio of the titanium silicalite molecular sieve is preferably 20-30, more preferably 22-28, more preferably 24-26.

[0071] In the present application, the calcination temperature is preferably 450-600°C, more preferably 480-570°C, more preferably 510-540°C.

[0072] In the present application, the binder preferably comprises one or more of silica sol, aluminum sol, carboxymethyl cellulose, polyvinyl pyrrolidone and nitric acid, more preferably silica sol, aluminum sol, carboxymethyl cellulose, polyvinyl pyrrolidone or nitric acid.

[0073] In the present application, the raw material for preparing dimethyl sulfoxide preferably comprises dimethyl sulfide and hydrogen peroxide.

[0074] In the present application, the raw material for preparing dimethyl sulfoxide further preferably comprises a dimethyl sulfoxide solvent. That is, the solvent for the reaction is dimethyl sulfoxide.

[0075] In the present application, the feed air speed of the raw material is preferably 2-12 h -1 , more preferably 4-10 h -1 , more preferably 6-8 h -1 .

[0076] The present application provides a method for preparing dimethyl sulfoxide, comprising the following steps:

[0077] 1) mixing dimethyl sulfide and a dimethyl sulfoxide solvent to obtain a mixed solution;

[0078] 2) adding hydrogen peroxide to the mixed solution obtained in the above step to carry out a mixing reaction, continuously stirring, and controlling the reaction temperature to obtain a mixed material;

[0079] 3) passing the mixed material obtained in the above step into a reaction device, and reacting again under the action of a shaped titanium-silicon molecular sieve catalyst to obtain dimethyl sulfoxide;

[0080] The shaped titanium-silicon molecular sieve is the shaped titanium-silicon molecular sieve in the application of any one of the above technical solutions.

[0081] The present application first mixes dimethyl sulfide and a dimethyl sulfoxide solvent to obtain a mixed solution. In particular, the present application selects dimethyl sulfoxide as the solvent, which is more conducive to the subsequent control of the stability of the subsequent reaction.

[0082] The present application further adds hydrogen peroxide to the mixed solution obtained in the above step to carry out a mixing reaction, continuously stirs, and controls the reaction temperature to obtain a mixed material.

[0083] In the present application, the concentration of the hydrogen peroxide is preferably 27%-30%, more preferably 27.5%-29.5%, and more preferably 28%-29%.

[0084] In the present application, the adding mode preferably comprises dropwise adding.

[0085] In the present application, in step 2), the controlled reaction temperature is preferably 25-30°C, more preferably 26-29°C, and more preferably 27-28°C.

[0086] In the present application, the mass content of hydrogen peroxide in the mixture in step 2) is preferably 0.65% to 1.70%, more preferably 0.8% to 1.50%, and even more preferably 1.0% to 1.30%.

[0087] The core of the step in the present application is to control the reaction temperature while monitoring the content of hydrogen peroxide in the mixture, thereby improving the selectivity of dimethyl sulfoxide.

[0088] In the present application, the molar ratio of hydrogen peroxide to dimethyl sulfide in the hydrogen peroxide is preferably (0.8 to 1.1) : 1, more preferably (0.85 to 1.05) : 1, and even more preferably (0.9 to 1.0) : 1. Specifically, the total amount of hydrogen peroxide in steps 2) and 3) is included.

[0089] In the present application, the total mass of hydrogen peroxide and dimethyl sulfide to the mass of dimethyl sulfoxide is preferably 1: (0.5 to 3), more preferably 1: (1 to 2.5), and even more preferably 1: (1.5 to 2).

[0090] In the present application, the mixture obtained by the above steps is introduced into a reaction device, and dimethyl sulfoxide is obtained after further reaction under the action of a shaped titanium-silicon molecular sieve catalyst.

[0091] In the present application, the introduction is preferably carried out during continuous stirring of the mixture.

[0092] In the present application, the stirring speed is preferably 200 to 1000 r / min, more preferably 350 to 850 r / min, and even more preferably 500 to 700 r / min.

[0093] In the present application, the feed airspeed during the introduction is preferably 2 to 12 h -1 , more preferably 4 to 10 h -1 , and even more preferably 6 to 8 h -1 .

[0094] In the present application, the reaction device preferably includes a fixed bed reactor or a tubular reactor.

[0095] In the present application, the temperature of the further reaction is preferably 25 to 45°C, more preferably 29 to 41°C, and even more preferably 33 to 37°C.

[0096] In the present application, the pressure of the further reaction is preferably atmospheric pressure.

[0097] In the present application, the selectivity of dimethyl sulfoxide prepared in the preparation method is preferably greater than or equal to 99%.

[0098] The application is a complete and detailed overall technical solution, which better guarantees the structure and composition of the shaped titanium-silicon molecular sieve, further improves the stability and controllability of the process route, and improves the reaction efficiency and the selectivity of dimethyl sulfoxide. The catalyst for producing dimethyl sulfoxide and the dimethyl sulfoxide preparation method can specifically include the following contents.

[0099] A catalyst for producing dimethyl sulfoxide and a dimethyl sulfoxide preparation method, comprising the following steps:

[0100] The shaped titanium-silicon molecular sieve is used as the catalyst, the volume space velocity is 2-12h -1 , the temperature is 25-45℃, and the reaction is carried out under normal pressure. The dimethyl sulfoxide selectivity is more than 99%.

[0101] Specifically, the shaped titanium-silicon molecular sieve is in the shape of a strip, a sphere, a cylinder, etc., and is preferably a cylinder with a size of 4-5mm*4-5mm. Specifically, the composition is: 1-2wt% of alumina, 90-95wt% of silicon oxide, and 4-5wt% of titanium oxide; the specific surface area is 150-300m 2 / g, the pore volume is 0.35-0.50ml / g, and the average pore size is 7-10nm.

[0102] Specifically, the purity of the raw material dimethyl sulfide is more than 99%, and is preferably more than 99.5%.

[0103] Specifically, the purity of the raw material hydrogen peroxide is 27-30%, and is preferably 27-28%.

[0104] Specifically, dimethyl sulfoxide is used as the solvent, and the addition amount is preferably m(dimethyl sulfoxide):m(raw material)=1-3:1.

[0105] Specifically, n(hydrogen peroxide):n(dimethyl sulfide)=(0.8-1.1):1, and preferably n(hydrogen peroxide):n(dimethyl sulfide)=(0.90-1.05):1.

[0106] Specifically, the feeding space velocity of the mixture is 2-12h -1 , and is preferably 3-5h -1 .

[0107] Specifically, the mixture needs to be pumped in through a feeding pump in a constant stirring process, and the stirring rate is 200-1000r / min, and is preferably 500-600r / min.

[0108] Specifically, the content of hydrogen peroxide in the mixture is 0.65-1.70%, and is preferably 0.70-0.85%.

[0109] Specifically, the reaction temperature is controlled to be 25-45℃.

[0110] Specifically, a fixed bed reactor, preferably a tubular reactor, is used.

[0111] Specifically, the method for preparing the shaped titanium silicalite molecular sieve comprises uniformly mixing the titanium silicalite molecular sieve, an aluminum source, a silicon source and a binder, shaping through a mold, and then drying and calcining. The key component, the titanium silicalite molecular sieve, is preferably small-grained, with a size of 150-450 nm; and the Si / Ti ratio is 20-30, preferably 21-25.

[0112] Referring to Figure 1 , Figure 1 An electron microscope image of the small-grained titanium silicalite molecular sieve prepared in the present application.

[0113] The above content of the present application provides a catalyst for producing dimethyl sulfoxide and a method for preparing dimethyl sulfoxide. The present application particularly designs a shaped titanium silicalite molecular sieve catalyst for dimethyl sulfoxide, which has a specific composition and structure, uses small-grained titanium silicalite molecular sieve as the core component of the catalyst, and adjusts the activity of the catalyst by incorporating a certain amount of alumina and silica, thereby better improving the selectivity of dimethyl sulfoxide preparation and realizing a process route under relatively mild conditions without using alkaline substances.

[0114] The present application also provides a corresponding method for preparing dimethyl sulfoxide, which uses small-grained titanium silicalite molecular sieve as the core component of the catalyst, adjusts the activity of the catalyst by incorporating a certain amount of alumina and silica, simultaneously uses self-produced dimethyl sulfoxide as a solvent to improve the solubility of the raw materials, uses a tubular reactor to realize the reaction of dimethyl sulfide and hydrogen peroxide under relatively mild conditions, can realize the selectivity of dimethyl sulfoxide of more than 99%, solves the problem that the prior art uses low-boiling-point solvents such as methanol (boiling point 64.7℃), acetone (boiling point 56.5℃), and isopropyl alcohol (boiling point 82.45℃), and needs to distill the solvents out for reuse in the product separation process, and the hydrogen peroxide starts to decompose at 60℃, which has the risk of explosion mixture. Moreover, the present application can also control the degree of mildness of the operating conditions by adjusting the activity of the catalyst to solve the problem of intense heat release in the oxidation reaction.

[0115] The application is verified by a large number of experiments, and the index of the catalyst used in the dimethyl sulfide and hydrogen peroxide reaction system and the preparation method thereof are determined. The shaped small-grain titanium-silicon molecular sieve is used as the catalyst, the reaction is carried out at 25-45 DEG C in a tubular reactor, the self-generated dimethyl sulfoxide is used as the solvent, the solubility problem of the raw material is solved, and then the dimethyl sulfide is treated at a high space velocity, so that the dimethyl sulfoxide can be produced by the reaction of dimethyl sulfide and hydrogen peroxide under relatively mild conditions without using alkaline substances, and the selectivity of the dimethyl sulfoxide is more than 99%. The preparation method provided by the application has the advantages of simple process, mild conditions, strong controllability, lower cost, and wide application prospect.

[0116] In order to further illustrate the application, the application of the shaped titanium-silicon molecular sieve in the preparation of dimethyl sulfoxide and a preparation method of dimethyl sulfoxide are described in detail in the following examples, but it should be understood that these examples are implemented on the premise of the technical scheme of the application, and detailed implementation modes and specific operation processes are given, which are only for further illustrating the features and advantages of the application, and are not a limitation on the claims of the application, and the protection scope of the application is not limited to the following examples.

[0117] Example 1

[0118] (1) Catalyst preparation: the titanium-silicon molecular sieve with a particle size of 230-400 nm, a specific surface area of 440 m 2 / g, a pore volume of 0.42 ml / g, and an average pore diameter of 4 nm is shaped into a cylindrical catalyst 1# with a size of 4-5 mm*4-5 mm, the content of silicon oxide in the catalyst is 92.82%, the content of aluminum oxide is 1.54%, and the content of titanium oxide is 4.66%;

[0119] (2) Preparation of raw materials: 123.64 g of hydrogen peroxide is added dropwise into a mixture of 65.1 g of dimethyl sulfide and 566.22 g of dimethyl sulfoxide, the reaction temperature is controlled at 30 DEG C, the rotation speed is 600 r / min, after the dropwise addition is completed, the stirring reaction is continued for 30 min, and a mixture is formed;

[0120] (3) Reaction stage: the catalyst loading amount of the tubular reactor is 10 ml, the feeding rate of the mixture is 0.83 ml / min, and the reaction temperature is controlled at 25 DEG C.

[0121] (4) The tubular reactor is a laboratory simulation device, the outer diameter is 30 mm, the inner diameter is 20 mm, the length is 300 mm, the catalyst is filled into the inner pipe, and the outer pipe is connected with a condensate liquid for temperature control. The tubular reactor is used in the following examples and comparative examples.

[0122] Example 2

[0123] (1) Catalyst preparation: Titanium silical molecular sieve with particle size of 230-400 nm, specific surface area of 440 m 2 / g, pore volume of 0.42 ml / g, average pore diameter of 4 nm was used to form a cylindrical catalyst 1# with size of 4-5 mm*4-5 mm, the catalyst contained 92.82% of silicon oxide, 1.54% of aluminum oxide and 4.66% of titanium oxide;

[0124] (2) Raw material preparation: 123.64 g of hydrogen peroxide was added dropwise into a mixture of 65.1 g of dimethyl sulfide and 94.37 g of dimethyl sulfoxide, the reaction temperature was controlled at 30°C, the rotation speed was 600 r / min, after the dropwise addition was completed, the stirring was continued for 30 min to form a mixture;

[0125] (3) Reaction stage: the catalyst loading was 10 ml, the feeding rate of the mixture was 0.83 ml / min; the reaction temperature was controlled at 25°C.

[0126] Comparative Example 1

[0127] (1) Catalyst preparation: Commercial titanium silical molecular sieve with specific surface area of 422 m 2 / g, pore volume of 0.27 ml / g, average pore diameter of 2.38 nm was used to form a cylindrical catalyst 2# with size of 4-5 mm*4-5 mm, the catalyst contained 93.02% of silicon oxide, 2.23% of aluminum oxide and 4.02% of titanium oxide;

[0128] (2) Raw material preparation: 123.64 g of hydrogen peroxide was added dropwise into a mixture of 65.1 g of dimethyl sulfide and 566.22 g of dimethyl sulfoxide, the reaction temperature was controlled at 30°C, the rotation speed was 600 r / min, after the dropwise addition was completed, the stirring was continued for 30 min to form a mixture;

[0129] (3) Reaction stage: the catalyst loading was 10 ml, the feeding rate of the mixture was 0.83 ml / min; the reaction temperature was controlled at 25°C.

[0130] Comparative Example 2

[0131] (1) Catalyst preparation: Titanium silical molecular sieve with particle size of 230-400 nm, specific surface area of 440 m 2 / g, pore volume of 0.42 ml / g, average pore diameter of 4 nm was used to form a cylindrical catalyst 3# with size of 4-5 mm*4-5 mm, the catalyst contained 92.28% of silicon oxide, 2.52% of aluminum oxide and 4.50% of titanium oxide;

[0132] (2) raw material preparation: 123.64 g of hydrogen peroxide was added dropwise into a mixture of 65.1 g of dimethyl sulfide and 566.22 g of dimethyl sulfoxide, the reaction temperature was controlled at 30°C, the rotation speed was 600 r / min, and after the dropwise addition was completed, the stirring was continued for 30 min to form a mixture;

[0133] (3) reaction stage: the catalyst loading was 10 ml, and the mixture feeding rate was 0.83 ml / min; the reaction temperature was controlled at 25°C.

[0134] The preparation process and products of the examples and comparative examples of the present application were analyzed.

[0135] The product analysis was performed by gas chromatography analysis, HP-5 chromatographic column (60 m), FID detector, 50°C stable for 1 min, temperature rising at a rate of 15°C / min to 280°C. The specific data are shown in Table 1. Table 1 is the analysis data of the preparation process of the examples and comparative examples of the present application.

[0136] Table 1

[0137] Experiment No. Dimethyl sulfide conversion, % Dimethyl sulfoxide selectivity, % Dimethyl sulfone selectivity, % Example 1 93.61 99.12 0.81 Example 2 60.38 99.63 0.37 Comparative Example 1 90.39 92.80 7.20 Comparative Example 2 92.47 98.66 2.34

[0138] The above provides a catalyst for producing dimethyl sulfoxide and a preparation method of dimethyl sulfoxide. In this paper, specific examples are used to explain the principles and implementation methods of the present application. The above examples are only used to help understand the method and core idea of the present application, including the best mode, and also enable any person skilled in the art to practice the present application, including manufacturing and using any device or system, and implementing any combined method. It should be noted that for those skilled in the art, without departing from the principles of the present application, some improvements and modifications can be made to the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application. The scope of the patent protection of the present application is defined by the claims, and can include other embodiments that can be thought of by those skilled in the art. If these other embodiments have structural elements that are not different from the language expression of the claims, or if they include equivalent structural elements that are not substantially different from the language expression of the claims, then these other embodiments should also be included in the scope of the claims.

Claims

1. Use of a shaped titanium silicalite molecular sieve in the preparation of dimethyl sulfoxide; The content of alumina in the shaped titanium silicalite molecular sieve is 1wt%-2wt%; The content of silicon oxide in the shaped titanium silicalite molecular sieve is 90wt%-95wt%; The content of titanium oxide in the shaped titanium silicalite molecular sieve is 4wt%-5wt%; The shaped titanium silicalite molecular sieve contains small crystal titanium silicalite molecular sieve; The size of the small crystal titanium silicalite molecular sieve is 150-450nm; The average pore size of the shaped titanium silicalite molecular sieve is 7-10nm; The lateral size of the shaped titanium silicalite molecular sieve is 4-5mm; The longitudinal size of the shaped titanium silicalite molecular sieve is 4-5mm; The shaped titanium silicalite molecular sieve has a specific surface area of 150 to 300 m 2 / g; The pore volume of the shaped titanium silicalite molecular sieve is 0.35-0.50ml / g; The raw material for preparing dimethyl sulfoxide further comprises a dimethyl sulfoxide solvent.

2. Use according to claim 1, characterized in that, The use is specifically the use as a catalyst; The shaped titanium silicalite molecular sieve is specifically a titanium silicalite molecular sieve after shaping and calcination.

3. Use according to claim 1, characterized in that, The shape of the shaped titanium silicalite molecular sieve comprises one or more of a strip shape, a spherical shape and a cylindrical shape.

4. Use according to claim 1, characterized in that, The preparation process of the shaped titanium silicalite molecular sieve comprises the following steps: The titanium silicalite molecular sieve, an aluminum source, a silicon source and a binder are uniformly mixed, shaped through a mold, and then calcined to obtain the shaped titanium silicalite molecular sieve.

5. Use according to claim 4, characterized in that, The Si / Ti ratio of the titanium silicalite molecular sieve is 20-30; The calcination temperature is 450-600℃; The binder comprises one or more of silica sol, aluminum sol, carboxymethyl cellulose, polyvinylpyrrolidone and nitric acid.

6. Use according to claim 1, characterized in that, The raw material for preparing dimethyl sulfoxide comprises dimethyl sulfide and hydrogen peroxide; The feedstock has a space velocity of 2 to 12 h -1 .

7. A process for the preparation of dimethyl sulfoxide, characterized in that, Comprises the following steps: 1) mixing dimethyl sulfide and a dimethyl sulfoxide solvent to obtain a mixed solution; 2) adding hydrogen peroxide to the mixed solution obtained in the above step to perform a mixing reaction, to obtain a mixed material; 3) introducing the mixed material obtained in the above step into a reaction device, and performing a reaction again under the action of the shaped titanium silicalite molecular sieve catalyst, to obtain dimethyl sulfoxide; The shaped titanium silicalite molecular sieve is the shaped titanium silicalite molecular sieve in the use of any one of claims 1-6.

8. The preparation method according to claim 7, characterized in that, The concentration of the hydrogen peroxide is 27%-30%; The adding mode comprises dropwise adding; In step 2), the reaction temperature is controlled to be 25-30℃; In step 2), the mass content of hydrogen peroxide in the mixed material is 0.65%-1.70%.

9. The preparation method according to claim 7, characterized in that, The molar ratio of hydrogen peroxide to dimethyl sulfide in the hydrogen peroxide is (0.8-1.1):1; The total mass of the hydrogen peroxide and dimethyl sulfide to the mass of dimethyl sulfoxide is 1:(0.5-3); The introduction is specifically during continuous stirring of the mixed material; The stirring speed is 200-1000r / min; The feed air velocity of the inlet is 2-12 h -1 .

10. The preparation method according to claim 7, characterized in that, The reaction device comprises a fixed bed reactor or a tubular reactor; The temperature of the reaction again is 25-45℃; The pressure of the reaction again is normal pressure; In the preparation method, the selectivity of the prepared dimethyl sulfoxide is greater than or equal to 99%.

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