Fluidized bed reaction device and preparation method of ethylene sulfate

Abstract

The invention discloses a fluidized bed reaction device and a preparation method of ethylene sulfate, the fluidized bed reaction device comprises a reaction cylinder with a jacket structure, the jacket of the reaction cylinder is provided with a cooling liquid inlet and a cooling liquid outlet, and a catalyst is filled between screens in the reaction cylinder. A central gas guide pipe is arranged on a gas distribution disc in the reaction cylinder, a plurality of side gas guide pipes are arranged on the outer edge of the gas distribution disc, a plurality of central gas guide holes are formed in the periphery of the pipe wall of the central gas guide pipe, and a plurality of side gas guide holes are formed in the side wall of one side of each side gas guide pipe; a circulating kettle mechanism for cooling is arranged outside the reaction cylinder body, a sealing head gas inlet communicated with a fluidizing gas source is formed in the feeding sealing head, and the gas inlet is communicated with the gas distribution disc. The preparation method adopts the reaction device to prepare the acid vinyl ester. The device has the advantages that the device is simple in structure, redundant heat can be quickly removed, and the conversion rate, the yield and the purity of the preparation method are very high.

Description

Technical Field

[0001] The invention relates to the technical field of fluidized bed reaction device and vinyl sulfate synthesis. Background Art

[0002] Gas-liquid-solid reaction is a common reaction. Take the synthesis of vinyl sulfate as an example. The synthesis of vinyl sulfate has been reported in the literature.

[0003] Patent CN109485633A reports that ethylene sulfite is oxidized to obtain ethylene sulfate product using hypochlorite as oxidant and ruthenium trichloride aqueous solution as catalyst. This method has been widely used in industrial production before, and it has the advantages of simple process, high yield and low cost. However, hypochlorite has poor chemical stability, low active oxygen content, large reaction demand, difficult product purification, and a large amount of salt-containing wastewater generated by the reaction, which has hindered the development of this process.

[0004] References (J. Am. Chem. Soc, 2013, 135 , 17176-17186) proposed using sodium periodate as an oxidant to oxidize vinyl sulfite to obtain vinyl sulfate. This has the advantages of mild reaction conditions and high product yield. However, sodium periodate is too expensive to be industrialized, and the product purification is difficult.

[0005] Patent CN104744427A uses potassium persulfate as an oxidant and ruthenium chloride aqueous solution as a catalyst to oxidize vinyl sulfite to obtain vinyl sulfate. This route has mild reaction conditions and is easy to control, but the cost of the oxidant and catalyst is relatively high, and a large amount of three wastes will be generated.

[0006] Patent CN111909129A discloses a method of using hydrogen peroxide as an oxidant to catalyze and oxidize vinyl sulfite through a solid catalyst to obtain a product. This method has a simple reaction, a high product yield, a theoretical byproduct of water, and a high atomic utilization rate. It meets the requirements of green chemistry required by the country and has a long-term development prospect. However, the controllability of mass transfer and heat transfer in the reaction process is low.

[0007] Among them, patent CN109422719A discloses a method for oxidizing vinyl sulfite in a jacketed intermittent reactor using titanium silicon molecular sieve (TS-1) as a catalyst, 30wt% hydrogen peroxide as an oxidant, and dichloromethane as a solvent. However, the reactor may have problems such as long reaction time, difficulty in filtering the product, and difficulty in recovering the catalyst.

[0008] Patent CN116425715A discloses a method for preparing vinyl sulfate by continuous oxidation of vinyl sulfite using a fixed-bed tubular reactor, which solves the problems of complex operation of intermittent reactors, difficult catalyst separation, and discontinuous reaction, and has a high raw material conversion rate (98%) and product selectivity (88%). Patents CN118530214A and CN118496195A point out that flow dead corners or short circuits may occur in fixed-bed reactors, and because the reaction is a highly exothermic reaction, local overheating may occur in fixed-bed reactors, causing high-concentration hydrogen peroxide to decompose and raw materials to hydrolyze, reducing the conversion rate and selectivity of the reaction, and leading to reduced catalyst service life, equipment overheating, reaction overpressure, etc., which seriously affect industrial production efficiency.

[0009] Existing methods have problems such as high process cost, difficulty in catalyst recovery, poor continuity, low controllability of mass and heat transfer, and low raw material conversion rate and product selectivity. Therefore, it is also necessary to develop a system device to improve the reaction efficiency, enable the entire system to operate continuously, and improve the controllability of mass and heat transfer during the reaction process to improve the production efficiency of the factory. Summary of the invention

[0010] The technical problem to be solved by the present invention is to provide a fluidized bed reaction device and a method for preparing vinyl sulfate. The reaction device has a simple structure and can greatly improve the preparation efficiency. The preparation method has a high raw material conversion rate, product yield and product purity.

[0011] In order to solve the above problems, the technical solution adopted by the present invention is: a fluidized bed reaction device, comprising: a reaction cylinder, wherein the upper and lower ends of the reaction cylinder are respectively provided with a discharge head with a head discharge port and a head gas outlet, and a feed head with a head feed port, the reaction cylinder is a jacket structure, the jacket of the reaction cylinder is provided with a coolant inlet and a coolant outlet, the upper and lower ends of the reaction cylinder are respectively provided with screens, the screens at the upper and lower ends are filled with catalysts, the lower end of the reaction cylinder is provided with a gas distribution plate, the middle position of the gas distribution plate is provided with a central air guide pipe, the outer edge of the gas distribution plate is arranged with a plurality of side air guide pipes, the side air guide pipes are arranged around the central air guide pipe, the pipe wall of the central air guide pipe is arranged with a plurality of central air guide holes, and each side air guide hole has ... A plurality of side air guide holes are arranged on the side wall of one side of the air pipe, and the side air guide holes on all the side air guide pipes are arranged in the same rotation direction in the circumferential direction; a circulating kettle mechanism for cooling the material is arranged outside the reaction cylinder body, and the circulating kettle mechanism includes a circulating kettle, and a circulating kettle input pipe and a circulating kettle output pipe are connected to the circulating kettle, the circulating kettle input pipe is connected to the material circulation outlet at the upper end of the reaction cylinder body, and the circulating kettle output pipe is connected to the material circulation inlet at the lower end of the reaction cylinder body, and the reaction material in the reaction cylinder body enters the circulating kettle through the circulating kettle input pipe to cool down and then flows back into the reaction cylinder body through the circulating kettle output pipe; a head air inlet connected to the fluidizing gas source is arranged on the feed head, and a head air inlet channel is arranged in the feed head, and the air inlet is connected to the gas distribution plate through the head air inlet channel.

[0012] Furthermore, in the aforementioned fluidized bed reaction device, the head feed port is connected to the reaction material input mechanism, and the reaction material input mechanism includes: a first material storage tank, a second material storage tank, a third material storage tank, and an emulsifying disperser, the first material storage tank is connected to the first material conveying pipe, and the first material conveying pipe is provided with a first one-way valve and a first conveying pump; the second material storage tank is connected to the second material conveying pipe, and the second material conveying pipe is provided with a second one-way valve and a second conveying pump; the third material storage tank is connected to the third material conveying pipe, and the third material conveying pipe is provided with a third one-way valve and a third conveying pump; the emulsifying disperser is provided with an emulsifying disperser input pipe and an emulsifying disperser output pipe, the first material conveying pipe and the second material conveying pipe are both connected to the premixing pipeline, the premixing pipeline and the third material conveying pipe are both connected to the emulsifying disperser input pipe, and the emulsifying disperser output pipe is connected to the head feed port.

[0013] Furthermore, in the aforementioned fluidized bed reaction device, a stirring paddle is provided in the circulating kettle.

[0014] Furthermore, in the aforementioned fluidized bed reaction device, the density of the central air guide holes on the central air guide pipe increases gradually from top to bottom.

[0015] Furthermore, in the aforementioned fluidized bed reaction device, the central air guide hole is in the shape of a hexagonal star.

[0016] Furthermore, in the aforementioned fluidized bed reaction device, the cooling liquid in the jacket layer of the reaction cylinder is water or an ethylene glycol aqueous solution.

[0017] A method for preparing vinyl sulfate, using a fluidized bed reaction device, wherein the reaction raw materials include organic solvent, vinyl sulfite, and hydrogen peroxide; a catalyst is filled between the screens at the upper and lower ends; the organic solvent, vinyl sulfite, and hydrogen peroxide are stored in a first material storage tank, a second material storage tank, and a third material storage tank, respectively; the three reaction raw materials are transported to an emulsifying disperser for mixing, and then enter a feed end cap through a feed end cap feed port of the emulsifying disperser, and the reactants in the feed end cap move upward and enter into a reaction cylinder; the fluid The chemical gas enters the gas distribution plate from the fluidizing gas source through the head air inlet and the head air inlet channel. The fluidizing gas in the gas distribution plate is ejected from the central air guide hole of the central air guide pipe and the side air guide holes of each side air guide pipe, thereby allowing the catalyst to flow in the reaction cylinder; the reaction materials in the reaction cylinder enter the circulation kettle from the material circulation outlet of the reaction cylinder through the circulation kettle input pipe to cool down, and the cooled reaction materials flow back into the reaction cylinder through the circulation kettle output pipe and the material circulation inlet; the liquid after the reaction is completed is output through the head outlet.

[0018] Furthermore, in the aforementioned method for preparing vinyl sulfate, the catalyst is a TS-1 or TS-2 titanium silicon molecular sieve catalyst loaded with Ni (0.01wt%), Ru (0.01wt%), Pb (0.01wt%) and Al (5wt%).

[0019] Furthermore, in the aforementioned method for preparing vinyl sulfate, the reaction temperature in the reaction cylinder is controlled at 20°C to 60°C.

[0020] Furthermore, in the aforementioned method for preparing vinyl sulfate, the flow ratio of the vinyl sulfite, the organic solvent, and the hydrogen peroxide is 1.0:6.4-8.3:1.6-2.7.

[0021] Furthermore, in the aforementioned method for preparing vinyl sulfate, the organic solvent is one of dichloromethane and dichloroethane.

[0022] Furthermore, in the aforementioned method for preparing vinyl sulfate, the hydrogen peroxide is a hydrogen peroxide aqueous solution with a mass fraction of 30-50%.

[0023] Furthermore, in the aforementioned method for preparing vinyl sulfate, a back pressure valve is provided at the gas outlet of the head, and the pressure of the back pressure valve is controlled at 0.2MPa~0.3MPa.

[0024] Furthermore, in the aforementioned method for preparing vinyl sulfate, the organic solvent and vinyl sulfite are premixed first, and the premixed organic solution is then simultaneously introduced into an emulsifying disperser for mixing with hydrogen peroxide.

[0025] Furthermore, in the aforementioned method for preparing vinyl sulfate, the average diameter of the titanium silicon molecular sieve catalyst is 1 to 20 mm.

[0026] The advantages of the present invention are: the fluidized bed reaction device described in the present invention has a simple structure, and a gas distribution plate, a central air duct and a side air duct are arranged in the reaction cylinder. The central air duct hole on the central air duct and the side air duct hole on the side air duct can transport the fluidized gas into the reaction cylinder, so as to purge the catalyst in the reaction cylinder and make the catalyst flow. On the one hand, it can prompt the catalyst to quickly conduct the excess reaction heat accumulated in the middle of the reaction cylinder to the jacket layer of the reaction cylinder, so as to quickly discharge the heat and prevent the local temperature from being too high and causing the product to hydrolyze. On the other hand, it can prompt the catalyst to fully contact with the reaction material, so as to improve the reaction efficiency. Furthermore, the setting of the circulating kettle mechanism outputs the material in the reaction cylinder into the circulating kettle for cooling and then flows back into the reaction cylinder, so as to further eliminate the excess heat generated by the reaction, thereby further reducing the risk of hydrolysis of the product generated during the reaction, thereby further improving the conversion rate and purity.

[0027] The method for preparing vinyl sulfate of the present invention adopts the above-mentioned fluidized bed reaction device for reaction, and the entire reaction conditions are mild and controllable, and continuous production can be achieved. Since the heat generated by the reaction can be quickly eliminated during the reaction, the reaction temperature can be controlled at 50°C to 60°C, which is significantly higher than the traditional preparation temperature, which can improve the catalyst activity, thereby improving the reaction efficiency and reaction conversion rate. The product yield of the preparation method is high and the purity is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the working principle of a fluidized bed reaction device described in the present invention.

[0029] Figure 2 It is a schematic diagram of the mechanism of a reaction cylinder and a circulating kettle mechanism in a fluidized bed reaction device described in the present invention.

[0030] Figure 3 It is a schematic diagram of the arrangement structure of a central air duct and a side air duct in a fluidized bed reaction device described in the present invention. DETAILED DESCRIPTION

[0031] The following is a detailed description of a fluidized bed reaction device and a method for preparing vinyl sulfate described in the present invention through specific embodiments.

[0032] First, a fluidized bed reaction device is introduced.

[0033] See also Figure 1 , Figure 2 As shown, a fluidized bed reaction device comprises: a reaction cylinder 1, wherein the upper and lower ends of the reaction cylinder 1 are respectively provided with a discharge head 2 with a head discharge port 21 and a head gas outlet 22, and a feed head 3 with a head feed port 31. The head gas outlet 22 is provided with a back pressure valve 221, and the pressure of the back pressure valve is controlled at 0.2MPa~0.3MPa.

[0034] The reaction cylinder 1 is a jacket structure, and a coolant inlet 101 and a coolant outlet 102 are provided on the jacket of the reaction cylinder 1. The coolant in the jacket of the reaction cylinder 1 is water or ethylene glycol aqueous solution. The coolant can be selected according to actual needs. The upper and lower ends of the reaction cylinder 1 are respectively provided with a top screen 11 and a bottom screen 12, and the material of the top screen 11 and the bottom screen 12 is S31603.

[0035] A catalyst is filled between the top mesh 11 and the bottom mesh 12. The catalyst is a TS-1 or TS-2 titanium silicon molecular sieve catalyst loaded with Ni (0.01wt%), Ru (0.01wt%), Pb (0.01wt%) and Al (5wt%). The average diameter of the titanium silicon molecular sieve catalyst is 1-20 mm.

[0036] A gas distribution plate 4 is provided at the lower end of the reaction cylinder 1. A central air guide pipe 41 is provided in the center of the gas distribution plate 4. A plurality of side air guide pipes 42 are arranged at intervals on the outer edge of the gas distribution plate 4. The side air guide pipes 42 are arranged around the central air guide pipe 41. A plurality of central air guide holes 411 are arranged around the tube wall of the central air guide pipe 41. The central air guide holes 411 on the central air guide pipe 41 are arranged more densely from top to bottom, so as to accelerate the discharge of heat at the lower end of the central air guide pipe 41. A plurality of side air guide holes 421 are provided on the side wall of one side of each side air guide pipe 42, and the side air guide holes 421 on all the side air guide pipes 42 are arranged in the same rotation direction in the circumferential direction, such as Figure 3 The central air guide hole 411 and the side air guide hole 421 are both in the shape of a hexagonal star.

[0037] A circulating kettle mechanism for cooling the material is arranged outside the reaction cylinder 1. The circulating kettle mechanism comprises a circulating kettle 5. The circulating kettle 5 is connected with a circulating kettle input pipe 51 and a circulating kettle output pipe 52. The circulation kettle input pipe 51 is connected to the material circulation outlet 13 at the upper end of the reaction cylinder 1, and the circulation kettle output pipe 52 is connected to the material circulation inlet 14 at the lower end of the reaction cylinder 1. The reaction material in the reaction cylinder 1 enters the circulation kettle 5 through the circulation kettle input pipe 51 to cool down, and then flows back to the reaction cylinder 1 through the circulation kettle output pipe 52. In order to improve the cooling effect, a stirring paddle 53 is provided in the circulation kettle 5. The setting of the circulation kettle mechanism plays a role in quickly removing the excess heat of the reaction material, ensuring that the reaction in the reaction cylinder 1 proceeds in a forward direction, effectively reducing the amount of product hydrolysis, thereby greatly improving the conversion rate and purity.

[0038] The feed head 3 is provided with a head air inlet 32 ​​connected to the fluidizing gas source. The feed head 3 is provided with a head air inlet channel 33 . The head air inlet 32 ​​is connected to the gas distribution plate 4 through the head air inlet channel 33 .

[0039] In this embodiment, the end cap feed port 31 is connected to a reaction material input mechanism, which includes: a first material storage tank 61, a second material storage tank 62, a third material storage tank 63, and an emulsifying disperser 64. The first material storage tank 61 is connected to a first material delivery pipe 611, and a first delivery pump 612 and a first check valve 613 are provided on the first material delivery pipe 611. The second material storage tank 62 is connected to a second material delivery pipe 621, and a second delivery pump 622 and a second check valve 623 are provided on the second material delivery pipe 621. The third material storage tank 63 is connected to a third material delivery pipe 631, and a third delivery pump 632 and a third check valve 633 are provided on the third material delivery pipe 631. The emulsifying disperser 64 is provided with an emulsifying disperser input pipe 641 and an emulsifying disperser output pipe 642. In this embodiment, the first material storage tank 61 is used to store organic solvents, the second material storage tank 62 is used to store vinyl sulfite, and the third material storage tank 63 is used to store hydrogen peroxide. The first material conveying pipe 611 and the second material conveying pipe 621 are first connected to the premixing pipe 65, and the premixing pipe 65 and the third material conveying pipe 631 are both connected to the emulsifier disperser input pipe 641, and the emulsifier disperser output pipe 642 is connected to the head feed port 31.

[0040] The method for preparing vinyl sulfate according to the present invention is described in detail below through specific examples.

[0041] Example 1: The reaction cylinder 1 between the top screen 11 and the bottom screen 12 is loaded with catalyst TS-1 loaded with Ni (0.01wt%), Ru (0.01wt%), Pb (0.01wt%) and Al (5wt%), and the filling volume is 95% of the volume of the reaction cylinder 1 between the top screen 11 and the bottom screen 12.

[0042] The reaction temperature is 50 oC; nitrogen is used as fluidizing gas with a flow rate of 50 L / h; ethylene dichloride is used as the organic solvent, and the flow ratios of vinyl sulfite, ethylene dichloride, and 50% by mass hydrogen peroxide solution are 1.0:6.4:1.6 respectively. The pressure of the back pressure valve 221 is set at 0.2MPa. Vinyl sulfite and ethylene dichloride are premixed in the premixing pipeline 65, and then enter the emulsifying disperser 64 together with the hydrogen peroxide solution for mixing and emulsification. The mixed liquid in the emulsifying disperser 64 enters the feed head 3 through the emulsifying disperser output pipe 642 and the head feed port 31, and the reactants in the feed head 3 enter the reaction cylinder 1 through the bottom screen 12 for reaction. Nitrogen enters the gas distribution plate 4 through the end cap gas inlet 32 ​​and the end cap gas inlet channel 33, and the nitrogen in the gas distribution plate 4 is ejected outward from the central gas guide hole 411 of the central gas guide pipe 41 and the side gas guide hole 421 of the side gas guide pipe 42, thereby purging the catalyst. Under the action of nitrogen purging, the catalyst flows in the reaction cylinder 1, thereby fully contacting and reacting with the reaction materials, and quickly conducts the heat generated by the reaction to the jacket layer of the reaction cylinder 1 to take it away, so as to improve the uniformity of the temperature distribution in the reaction cylinder 1 and avoid the situation where the local reaction temperature in the reaction cylinder 1 is too high and the product is hydrolyzed. Once the pressure in the reaction cylinder 1 exceeds 0.2MPa, the gas in the reaction cylinder 1 will be discharged from the end cap gas outlet 22 through the back pressure valve 221. At the same time, the reaction materials in the reaction cylinder 1 continuously enter the circulation kettle 5 through the circulation kettle input pipe 51 for stirring and cooling, and the reaction materials after the plate cooling are refluxed to the reaction cylinder 1 through the circulation kettle output pipe 52. The circulating kettle performs auxiliary temperature control, which can remove the reaction heat in the reaction cylinder 1 in time, thereby further effectively avoiding the risk of product hydrolysis.

[0043] After the reaction is finished, the reaction liquid is discharged from the end cap outlet 21. After the reaction is stable, sampling and analysis are performed. The gas chromatography shows that the vinyl sulfite conversion rate is 99.99% and the vinyl sulfate selectivity is 96.68%. The separation yield of pure vinyl sulfate obtained by the reaction is 95.78% and the purity is 99.8%.

[0044] Example 2: The reaction cylinder 1 between the top mesh 11 and the bottom mesh 12 is fully filled with the catalyst TS-1 loaded with Ni (0.01 wt %), Ru (0.01 wt %), Pb (0.01 wt %) and Al (5 wt %).

[0045] The reaction temperature is 50 oC; nitrogen is used as fluidizing gas with a flow rate of 50 L / h; ethylene dichloride is used as the organic solvent, and the flow ratios of vinyl sulfite, ethylene dichloride, and 50% by mass hydrogen peroxide solution are 1.0:6.4:1.6 respectively. The pressure of the back pressure valve 221 is set at 0.3MPa. Vinyl sulfite and ethylene dichloride are premixed in the premixing pipeline 65, and then enter the emulsifying disperser 64 together with the hydrogen peroxide solution for mixing and emulsification. The mixed liquid in the emulsifying disperser 64 enters the feed head 3 through the emulsifying disperser output pipe 642 and the head feed port 31, and the reactants in the feed head 3 enter the reaction cylinder 1 through the bottom screen 12 for reaction. Nitrogen enters the gas distribution plate 4 through the end cap air inlet 32 ​​and the end cap air inlet channel 33, and the nitrogen in the gas distribution plate 4 is ejected outward from the central air guide hole 411 of the central air guide pipe 41 and the side air guide hole 421 of the side air guide pipe 42, thereby purging the catalyst. Under the action of nitrogen purging, the catalyst flows in the reaction cylinder 1, so as to fully contact and react with the reaction materials, and can quickly conduct the heat generated by the reaction to the jacket layer of the reaction cylinder 1 to improve the uniformity of the temperature distribution in the reaction cylinder 1. When the pressure in the reaction cylinder 1 exceeds 0.3MPa, the gas in the reaction cylinder 1 is discharged from the end cap air outlet 22 through the back pressure valve 221. At the same time, the reaction materials in the reaction cylinder 1 continuously enter the circulation kettle 5 through the circulation kettle input pipe 51 for stirring and cooling, and the reaction materials after the plate cooling are refluxed into the reaction cylinder 1 through the circulation kettle output pipe 52. The circulation kettle performs auxiliary temperature control, which can remove the reaction heat in the reaction cylinder 1 in time.

[0046] After the reaction stabilized, samples were taken for analysis, and the gas chromatography showed that the vinyl sulfite conversion rate was 99.95%, and the vinyl sulfate selectivity was 91.23%. The pure vinyl sulfate obtained in the reaction had a separation yield of 90.28% and a purity of 99.7%.

[0047] Example 3: Catalyst TS-1 loaded with Ni (0.01 wt%), Ru (0.01 wt%), Pb (0.01 wt%) and Al (5 wt%) was loaded between the top mesh 11 and the bottom mesh 12 in the reaction cylinder 1. The loading volume was 95% of the volume of the reaction cylinder 1 between the top mesh 11 and the bottom mesh 12.

[0048] Set the reaction temperature to 50 oC; No fluidizing gas is introduced in this embodiment. Dichloromethane is used as the organic solvent, and the flow ratios of vinyl sulfite, dichloromethane, and 30% by mass hydrogen peroxide solution are 1.0:6.4:2.7 respectively. The pressure of the back pressure valve 221 is set at 0.2MPa. Vinyl sulfite and dichloromethane are premixed in the premixing pipeline 65, and then enter the emulsifying disperser 64 together with the hydrogen peroxide solution for mixing and emulsification. The mixed liquid in the emulsifying disperser 64 enters the feed head 3 through the emulsifying disperser output pipe 642 and the head feed port 31, and the reactants in the feed head 3 enter the reaction cylinder 1 through the bottom screen 12 for reaction. Nitrogen enters the gas distribution plate 4 through the head air inlet 32 ​​and the head air inlet channel 33, and the nitrogen in the gas distribution plate 4 is sprayed outward from the central air guide hole 411 of the central air guide pipe 41 and the side air guide hole 421 of the side air guide pipe 42, thereby purging the catalyst. Under the action of nitrogen purge, the catalyst flows in the reaction cylinder 1, so as to fully contact and react with the reaction materials, and can quickly conduct the heat generated by the reaction to the jacket layer of the reaction cylinder 1 to improve the uniformity of the temperature distribution in the reaction cylinder 1. The pressure in the reaction cylinder 1 exceeds 0.2MPa, and the gas in the reaction cylinder 1 is discharged from the head outlet 22 through the back pressure valve. At the same time, the reaction materials in the reaction cylinder 1 continuously enter the circulation kettle 5 through the circulation kettle input pipe 51 for stirring and cooling, and the reaction materials after the plate cooling are refluxed into the reaction cylinder 1 through the circulation kettle output pipe 52. The circulation kettle performs auxiliary temperature control, which can remove the reaction heat in the reaction cylinder 1 in time.

[0049] After the reaction stabilized, samples were taken for analysis, and the gas chromatography showed that the vinyl sulfite conversion rate was 95.65%, and the vinyl sulfate selectivity was 88.43%. The pure vinyl sulfate obtained in the reaction had an isolation yield of 83.61% and a purity of 99.5%.

[0050] In this embodiment, no fluidizing gas is introduced, and the heat generated by the reaction is only quickly removed through the circulation kettle, so the conversion rate is reduced.

[0051] Example 4: The catalyst TS-2 loaded with Ni (0.01 wt%), Ru (0.01 wt%), Pb (0.01 wt%) and Al (5 wt%) was loaded in the reaction cylinder 1 between the top screen 11 and the bottom screen 12. The loading volume was 95% of the volume of the reaction cylinder 1 between the top screen 11 and the bottom screen 12.

[0052] Set the reaction temperature to 60 oC; nitrogen is used as fluidizing gas with a flow rate of 80 L / h; ethylene dichloride is used as the organic solvent, and the flow ratios of vinyl sulfite, ethylene dichloride, and 30% by mass hydrogen peroxide solution are 1.0:8.3:2.3 respectively. The pressure of the back pressure valve 221 is set at 0.3MPa. Vinyl sulfite and ethylene dichloride are premixed in the premixing pipeline 65, and then enter the emulsifying disperser 64 together with the hydrogen peroxide solution for mixing and emulsification. The mixed liquid in the emulsifying disperser 64 enters the feed head 3 through the emulsifying disperser output pipe 642 and the head feed port 31, and the reactants in the feed head 3 enter the reaction cylinder 1 through the bottom screen 12 for reaction. Nitrogen enters the gas distribution plate 4 through the end cap gas inlet 32 ​​and the end cap gas inlet channel 33, and the nitrogen in the gas distribution plate 4 is ejected outward from the central gas guide hole 411 of the central gas guide pipe 41 and the side gas guide hole 421 of the side gas guide pipe 42, thereby purging the catalyst. Under the action of nitrogen purging, the catalyst flows in the reaction cylinder 1, so as to fully contact and react with the reaction materials, and can quickly conduct the heat generated by the reaction to the jacket layer of the reaction cylinder 1 to improve the uniformity of the temperature distribution in the reaction cylinder 1. The pressure in the reaction cylinder 1 exceeds 0.3MPa, and the gas in the reaction cylinder 1 is discharged from the end cap gas outlet 22 through the back pressure valve 221. At the same time, the reaction materials in the reaction cylinder 1 continuously enter the circulation kettle 5 through the circulation kettle input pipe 51 for stirring and cooling, and the reaction materials after the plate cooling are refluxed into the reaction cylinder 1 through the circulation kettle output pipe 52. The circulation kettle performs auxiliary temperature control, which can remove the reaction heat in the reaction cylinder 1 in time.

[0053] After the reaction stabilized, samples were taken for analysis, and the gas chromatography showed that the vinyl sulfite conversion rate was 99.69%, and the vinyl sulfate selectivity was 95.36%. The separation yield of pure vinyl sulfate obtained in the reaction was 94.26%, and the purity was 99.8%.

[0054] From the above embodiments, it can be concluded that the fluidized bed reaction device described in the present invention has a simple structure. A gas distribution plate, a central air duct and a side air duct are arranged in the reaction cylinder. The central air duct hole on the central air duct and the side air duct hole on the side air duct can transport the fluidized gas into the reaction cylinder, thereby sweeping the catalyst in the reaction cylinder to make the catalyst flow. On the one hand, it can prompt the catalyst to quickly transfer the excess reaction heat accumulated in the middle to the jacket layer of the reaction cylinder, so that the heat can be quickly discharged to prevent the local temperature from being too high and causing the product to hydrolyze. On the other hand, it can promote the catalyst to fully contact with the reaction material, thereby improving the reaction efficiency. Furthermore, the setting of the circulating kettle mechanism outputs the material in the reaction cylinder into the circulating kettle for cooling and then sends it into the reaction cylinder to further eliminate the excess heat generated by the reaction, thereby further reducing the risk of hydrolysis of the product generated during the reaction, thereby further improving the conversion rate and purity.

[0055] The method for preparing vinyl sulfate of the present invention adopts the above-mentioned fluidized bed reaction device for reaction, and the entire reaction conditions are mild and controllable, and continuous production can be achieved. Since the heat generated by the reaction can be quickly eliminated during the reaction, the reaction temperature can be controlled at 50°C to 60°C, which is significantly higher than the traditional preparation temperature, which can improve the catalyst activity, thereby improving the reaction efficiency and reaction conversion rate. The preparation method has high product yield and high purity.

Claims

1. A fluidized bed reaction device, comprising: A reaction cylinder, wherein the upper and lower ends of the reaction cylinder are respectively provided with a discharge head with a discharge port and a gas outlet, and a feed head with a feed port, wherein the reaction cylinder is a jacket structure, the jacket of the reaction cylinder is provided with a coolant inlet and a coolant outlet, the upper and lower ends of the reaction cylinder are respectively provided with screens, the screens at the upper and lower ends are filled with catalysts, a gas distribution plate is provided at the lower end of the reaction cylinder, a central air duct is provided at the middle position of the gas distribution plate, a plurality of side air ducts are arranged at the outer edge of the gas distribution plate, the side air ducts are arranged around the central air duct, a plurality of central air duct holes are arranged around the tube wall of the central air duct, and a plurality of side air ducts are provided on the side wall of one side of each side air duct The side air guide holes are arranged on all the side air guide pipes in the same rotation direction in the circumferential direction; a circulating kettle mechanism for cooling the material is arranged outside the reaction cylinder body, the circulating kettle mechanism comprises a circulating kettle, a circulating kettle input pipe and a circulating kettle output pipe are connected to the circulating kettle, the circulating kettle input pipe is connected to the material circulation outlet at the upper end of the reaction cylinder body, the circulating kettle output pipe is connected to the material circulation inlet at the lower end of the reaction cylinder body, the reaction material in the reaction cylinder body enters the circulating kettle through the circulating kettle input pipe to cool down, and then flows back into the reaction cylinder body through the circulating kettle output pipe; a head air inlet connected to the fluidizing gas source is arranged on the feed head, a head air inlet channel is arranged in the feed head, and the air inlet is connected to the gas distribution plate through the head air inlet channel.

2. A fluidized bed reaction device according to claim 1, characterized in that: The end cap feed port is connected to a reaction material input mechanism, which comprises: a first material storage tank, a second material storage tank, a third material storage tank, and an emulsifying disperser. The first material storage tank is connected to a first material conveying pipe, on which a first one-way valve and a first conveying pump are provided; the second material storage tank is connected to a second material conveying pipe, on which a second one-way valve and a second conveying pump are provided; the third material storage tank is connected to a third material conveying pipe, on which a third one-way valve and a third conveying pump are provided; an emulsifying disperser input pipe and an emulsifying disperser output pipe are provided on the emulsifying disperser, the first material conveying pipe and the second material conveying pipe are both connected to a premixing pipeline, the premixing pipeline and the third material conveying pipe are both connected to the emulsifying disperser input pipe, and the emulsifying disperser output pipe is connected to the end cap feed port.

3. A fluidized bed reaction device according to claim 1, characterized in that: A stirring paddle is provided in the circulation kettle.

4. A fluidized bed reaction device according to claim 1, characterized in that: The density of the central air guide holes on the central air guide tube increases gradually from top to bottom.

5. A fluidized bed reaction device according to claim 1, characterized in that: The central air guide hole adopts a hexagonal star shape.

6. A fluidized bed reaction device according to claim 1, characterized in that: The cooling liquid in the jacket layer of the reaction cylinder is water or ethylene glycol aqueous solution.

7. A method for preparing vinyl sulfate, characterized in that: A fluidized bed reaction device as described in claims 1 to 6 is used, wherein the reaction raw materials include organic solvent, vinyl sulfite, and hydrogen peroxide; a catalyst is filled between the screens at the upper and lower ends; the organic solvent, vinyl sulfite, and hydrogen peroxide are stored in the first material storage tank, the second material storage tank, and the third material storage tank, respectively, and the three reaction raw materials are transported to the emulsifier disperser for mixing, and then enter the feed head through the head feed port from the emulsifier disperser, and the reactants in the feed head move upward into the reaction cylinder; the fluidizing gas enters the gas distribution plate from the fluidizing gas source through the head air inlet and the head air inlet channel, and the fluidizing gas in the gas distribution plate is ejected from the central air guide hole of the central air guide pipe and the side air guide hole of each side air guide pipe, so that the catalyst flows in the reaction cylinder; the reaction material in the reaction cylinder enters the circulation kettle from the material circulation outlet of the reaction cylinder through the circulation kettle input pipe to cool down, and the cooled reaction material flows back into the reaction cylinder through the circulation kettle output pipe and the material circulation inlet; the liquid after the reaction is completed is output through the head outlet.

8. The method for preparing vinyl sulfate according to claim 9, characterized in that: The catalyst is a TS-1 or TS-2 titanium silicon molecular sieve catalyst loaded with Ni (0.01wt%), Ru (0.01wt%), Pb (0.01wt%) and Al (5wt%).

9. The method for preparing vinyl sulfate according to claim 7, characterized in that: The reaction temperature in the reaction cylinder is controlled at 20°C to 60°C.

10. The method for preparing vinyl sulfate according to claim 7, characterized in that: The flow ratio of the vinyl sulfite, the organic solvent and the hydrogen peroxide is 1.0:6.4-8.3:1.6-2.

7.

11. The method for preparing vinyl sulfate according to claim 7, characterized in that: The organic solvent is one of dichloromethane and dichloroethane.

12. The method for preparing vinyl sulfate according to claim 7, characterized in that: The hydrogen peroxide solution is a hydrogen peroxide aqueous solution with a mass fraction of 30-50%.

13. The method for preparing vinyl sulfate according to claim 7, characterized in that: The head outlet is equipped with a back pressure valve, and the pressure of the back pressure valve is controlled at 0.2MPa~0.3MPa.

14. The method for preparing vinyl sulfate according to claim 7, characterized in that: The organic solvent and vinyl sulfite are premixed first, and the premixed organic solution is then simultaneously introduced into the emulsifying disperser for mixing with hydrogen peroxide.

15. The method for preparing vinyl sulfate according to claim 9, characterized in that: The average diameter of titanium silicate molecular sieve catalyst is 1~20 mm.

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