CN107641816B - Continuous electrochemical reaction device and method for continuous oxidation of thioether substrate to sulfone - Google Patents

Abstract

The invention provides a continuous electrochemical reaction device and a method for continuously oxidizing thioether substrates into sulfone. The continuous electrochemical reaction device comprises a continuous electrochemical reactor and a temperature control device, wherein the continuous electrochemical reactor comprises a reactor body, the reactor body is provided with a reaction cavity, a central electrode and a peripheral electrode are arranged in the reaction cavity, and the peripheral electrode is arranged around the central electrode; the temperature control device is arranged around the reactor body. A central electrode and a peripheral electrode are arranged in a reaction cavity of the continuous electrochemical reactor, the peripheral electrode is arranged around the central electrode, and the unit volume of the reactor has a larger heat exchange area, so that the material has higher reaction efficiency. The continuous flowing reactor has the advantages of high reactant flow speed in the reactor, short treatment time, high reaction efficiency and less side reaction. Not only the reaction is stable compared with batch reaction, but also the temperature control is simple and the operation is convenient, and the volume of the equipment is reduced.

Description

Continuous electrochemical reaction device and method for continuous oxidation of thioether substrate to sulfone

technical field

The invention relates to the field of electrochemical reactions, in particular, to a continuous electrochemical reaction device and a method for continuously oxidizing sulfide substrates into sulfones.

Background technique

Compared with traditional organic synthesis, organic electrosynthesis has significant advantages: (1) The electrochemical reaction is realized by the gain and loss of electrons on the electrode by reactants. In principle, no other reagents need to be added, which reduces material consumption and thus reduces environmental pollution. (2) The selectivity is very high, and the side reactions are reduced, so that the product purity and yield are high, which greatly simplifies the product separation and purification work; (3) The reaction is carried out at normal temperature and pressure or low pressure, which saves energy. It is very beneficial to reduce energy and equipment investment; (4) the process flow is simple, and the reaction is easy to control.

Most of the existing electrochemical reactors are batch electrochemical reactors. After a simple batch electrochemical reactor is regularly fed with a certain amount of reactants (electrolyte), the reaction products are released after a certain reaction time. Obviously, with the progress of the electrochemical reaction and the accompanying chemical reaction, the reactant is continuously consumed, its concentration is continuously reduced, the product is continuously generated, and the product concentration is continuously increased (here it is assumed that in the whole reactor, the reactants and products are mixed The concentration profile is uniform and has the same reaction time for each reactant). The operation of batch electrochemical reactor consumes a large amount of labor and is generally only suitable for small-scale production or occasions where products are provided intermittently.

Taking the oxidation of thioether substrates to sulfones as an example, the existing oxidation reactions usually use chemical oxidants, such as hydrogen peroxide to alkyl or aryl sulfides under the catalysis of sodium tungstate to obtain a higher yield and conversion rate. sulfone. The Inorganic Peroxide Oxone Enables Oxidation of α-Amino Sulfide Substrates Sulfones and sulfoxides are obtained, and the molybdenum peroxide derivative catalyst can achieve higher selectivity and yield oxidation of a series of aliphatic or aromatic sulfide substrates to obtain sulfone or sulfoxide products. Kazuhiko reported the oxidation of various aromatic thioether and aliphatic thioether substrates using mercury oxide/iodine to obtain sulfone products in high yields. This type of chemical oxidant usually has a large amount of use, and the post-treatment brings more hazards of three wastes and heavy metal pollution.

In the 1970s, a tank reactor was developed using graphite as the anode and aluminum as the cathode to oxidize the dimethyl sulfide substrate to sulfone by electrochemical oxidation under acidic conditions, obtaining high yields and ideal conditions. current efficiency. However, in the subsequent development of electrochemistry, cases of industrial application are almost rare.

Intermittent operation has shortcomings such as the need for auxiliary time, large size of equipment required for batch scale-up, low heat exchange efficiency, long reaction period, low production efficiency, and large floor space. current, will increase equipment costs and operational safety risks. At the same time, the intermittent operation is prone to uneven local reactions and many side reactions, resulting in unstable product quality.

SUMMARY OF THE INVENTION

The main purpose of the present invention is to provide a continuous electrochemical reaction device and a method for continuously oxidizing sulfide substrates to sulfones, so as to solve the problem of low electrochemical reaction efficiency in the prior art.

In order to achieve the above object, according to one aspect of the present invention, a continuous electrochemical reaction device is provided, the continuous electrochemical reaction device includes a continuous electrochemical reactor and a temperature control device, the continuous electrochemical reactor includes a reactor body, and the reaction The reactor body has a reaction chamber, a central electrode and a peripheral electrode are arranged in the reaction chamber, and the peripheral electrodes are arranged around the central electrode; the temperature control device is arranged around the reactor body.

Further, the reactor body includes: the side wall of the reactor, the upper cover of the reactor and the lower cover of the reactor, the side wall of the reactor, the upper cover of the reactor and the lower cover of the reactor enclose a reaction chamber, and the upper cover of the reactor is closed on the reaction chamber. The top of the side wall of the reactor is closed, and the lower cover of the reactor is closed on the bottom of the side wall of the reactor.

Further, the side wall of the reactor and the upper cover of the reactor are connected by an upper flange, and the side wall of the reactor and the lower cover of the reactor are connected by a lower flange.

Further, the reactor body also includes: a raw material inlet and a product outlet, the raw material inlet is located at the lower half of the side wall of the reactor; the product outlet is located at the upper half of the side wall of the reactor.

Further, the reactor body also includes: an inert gas inlet and a tail gas outlet, the inert gas inlet is located in the upper half of the side wall of the reactor, and is located above the product outlet; the exhaust gas outlet is located in the upper half of the side wall of the reactor, and is located in above the inert gas inlet.

Further, the continuous electrochemical reactor further includes: an inert gas flowmeter, which is communicated with the inert gas inlet.

Further, the temperature control device is a temperature control jacket, and the temperature control jacket includes a jacket cavity arranged around the continuous electrochemical reactor, and a jacket inlet and a jacket outlet arranged on the side wall of the jacket cavity.

Further, the jacket inlet is located at the lower half of the side wall of the jacket cavity, and the jacket outlet is located at the upper half of the side wall of the jacket cavity.

Further, the continuous electrochemical reaction device further includes a temperature measuring device, and the temperature measuring device is connected with the product outlet.

Further, the material of the central electrode and the peripheral electrode is selected from any one of the following: graphite, Pt, Cu, Ag, Zn, Pb, Au, Fe, Ti, Ni, alloy or metal oxide, and the metal oxide is PbO ₂ , CuO, Ag ₂ O, Fe ₂ O ₃ , TiO ₂ or NiO; the material of the side wall of the reactor is metal material, polytetrafluoroethylene, PP or metal material sprayed with polytetrafluoroethylene, and the metal material is iron or stainless steel.

Further, the shape of the central electrode is rod-shaped or mesh-shaped; the peripheral electrodes are sheet-shaped or mesh-shaped.

Further, the distance between the central electrode and the peripheral electrode is 0.1-5 cm.

Further, the distance between the central electrode and the peripheral electrode is 0.5-3 cm.

Further, a diaphragm is arranged between the central electrode and the peripheral electrode.

Further, the reaction chamber is a cylinder, and the length-diameter ratio of the reaction chamber is 3-300:1.

Further, the aspect ratio of the reaction chamber is 10-100:1.

Further, the continuous electrochemical reaction device also includes an electrolytic reaction power supply electrically connected with the central electrode and the peripheral electrode, and the electrolytic reaction power supply is a DC voltage-stabilized and constant-current reaction power supply.

Further, there are multiple continuous electrochemical reactors, and multiple continuous electrochemical reactors are arranged in series or in parallel.

Further, the continuous electrochemical reaction device also includes a raw material device and a raw material power conveying device, and the raw material device is communicated with the continuous electrochemical reactor through the raw material power conveying device.

In order to achieve the above object, according to one aspect of the present invention, there is provided a method for continuously oxidizing a thioether-based substrate into a sulfone, the method comprising continuously feeding the thioether-based substrate into any one of the above-mentioned continuous electrochemical reaction devices Oxidize.

Further, the method further includes sampling and detecting at the product outlet of the continuous electrochemical reaction device, so as to control the molar ratio of the raw material to the product of the thioether substrate to be less than 1%.

Further, the central electrode in the continuous electrochemical reaction device is a graphite electrode, and the peripheral electrode is zinc or copper.

By applying the technical solution of the present invention, a central electrode and a peripheral electrode are arranged in the reaction chamber of the continuous electrochemical reactor, and the peripheral electrodes are arranged around the central electrode, and the unit volume of the reactor has a large heat exchange area, so that the material can be heated in the continuous electrochemical reactor. The chemical reactor has a faster reaction efficiency, the reaction materials are continuously entered, and the reaction products are continuously discharged. This continuous flow reactor enables the reactants to flow quickly in the reactor, the processing time is short, the reaction efficiency is improved, and side reactions are reduced. . Not only is it more stable than batch reaction, but also the temperature control is simple and convenient to operate, which reduces the size of the equipment.

Description of drawings

The accompanying drawings forming a part of the present application are used to provide further understanding of the present invention, and the exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the attached image:

FIG. 1 shows a schematic structural diagram of a continuous electrochemical reaction device provided according to a preferred embodiment of the present invention; and

FIG. 2 shows a schematic structural diagram of a continuous electrochemical reaction device provided according to another preferred embodiment of the present invention.

Wherein, the above-mentioned drawings include the following reference signs:

10. Continuous electrochemical reactor; 13. Central electrode; 14. Peripheral electrode;

11. Reactor body; 111, Reaction chamber; 112, Reactor side wall; 113, Reactor upper cover; 114, Reactor lower cover;

115, raw material inlet; 116, product outlet; 117, inert gas inlet; 118, tail gas outlet; 12, inert gas flow meter;

20, temperature control device; 201, jacket inlet; 202, jacket outlet;

30. Temperature measuring device; 101. Upper flange; 102. Lower flange;

40. Raw material device; 50. Raw material power conveying device; 60. Power source for electrolysis reaction.

Detailed ways

It should be noted that the embodiments in the present application and the features of the embodiments may be combined with each other in the case of no conflict. The present invention will be described in detail below with reference to the embodiments.

As mentioned in the background art, the current electrochemical reaction has the problem of low reaction efficiency. In order to improve this situation, in a typical embodiment of the present application, a continuous electrochemical reaction device is provided, as shown in Figure 1 As shown, the continuous electrochemical reaction device includes: a continuous electrochemical reactor 10 and a temperature control device 20, the continuous electrochemical reactor 10 includes a reactor body 11, the reactor body 11 has a reaction chamber 111, and the reaction chamber 111 is provided with The central electrode 13 and the peripheral electrode 14 are arranged around the central electrode 13 ; the temperature control device 20 is arranged around the reactor body 11 .

In the continuous electrochemical reaction device provided by the present application, the central electrode 13 and the peripheral electrodes 14 are arranged in the reaction chamber 111 of the continuous electrochemical reactor 10, and the peripheral electrodes 14 are arranged around the central electrode 13, and the unit reactor volume has a larger volume. The heat exchange area is large, so that the material has a faster reaction efficiency in the continuous electrochemical reactor 10, the reaction material is continuously entered, and the reaction product is continuously discharged. This continuous flow reactor makes the reactant flow fast in the reactor, The treatment time is short, the reaction efficiency is improved, and the side reactions are reduced. Not only is it more stable than batch reaction, but also the temperature control is simple and convenient to operate, which reduces the size of the equipment.

The specific structure of the above-mentioned continuous electrochemical reactor 10 can be appropriately improved on the basis of the existing electrochemical reactor structure. In a preferred embodiment of the present application, the reactor body 11 includes: a reactor side wall 112 , a reactor upper cover 113 and a reactor lower cover 114 , the reactor side wall 112 , the reactor upper cover 113 and the reactor The lower cover 114 encloses the reaction chamber 111 , the reactor upper cover 113 is covered on the top of the reactor side wall 112 , and the reactor lower cover 114 is covered with the bottom of the reactor side wall 112 . The reactor of this structure is easy to assemble and disassemble.

In the above preferred embodiment, the specific connection method of the reactor side wall 112 and the reactor upper cover 113 and the reactor lower cover 114 is not limited, as long as the continuous electrochemical reaction can be realized. In a preferred embodiment of the present application, the reactor side wall 112 and the reactor upper cover 113 are connected through the upper flange 101 , and the reactor side wall 112 and the reactor lower cover 114 are connected through the lower flange 102 . The flange connection makes the connection between the upper reactor cover 113 and the lower reactor cover 114 and the side wall 112 of the reactor tighter, and the sealing performance is higher.

In the above-mentioned continuous electrochemical reactor 10, the reaction material continuously enters the reactor, and the product continuously discharges from the reactor. Therefore, the continuous electrochemical reactor 10 also includes a raw material inlet 115 and a product outlet 116, and the specific setting positions can be reasonably set according to actual needs. In a preferred embodiment of the present application, the reactor body 11 further includes a raw material inlet 115 and a product outlet 116 . The raw material inlet 115 is located in the lower half of the reactor side wall 112 ; the product outlet 116 is located on the upper part of the reactor side wall 112 . half. The arrangement of the raw material inlet 115 on the bottom and the product outlet 116 on the top can help make the raw materials react sufficiently before being discharged.

In order to further improve the safety and stability of the above-mentioned continuous electrochemical reaction device, in a preferred embodiment of the present application, the reactor body 11 further includes an inert gas inlet 117 and a tail gas outlet 118, and the inert gas inlet 117 is located on the side of the reactor The upper half of the wall 112 is located above the product outlet 116 ; the tail gas outlet 118 is located on the upper half of the reactor side wall 112 and above the inert gas inlet 117 . The distance between the inert gas inlet 117 and the product outlet 116 is determined according to the flow rate of the gas produced by the electrolysis, so as to more fully dilute the gas (usually hydrogen or oxygen) produced by the electrolysis. The tail gas outlet 118 is located at the highest position of the reaction chamber 111, and there is a sufficient distance between the inert gas inlet 117 and the tail gas outlet 118, so that there is sufficient space to dilute the gas. Continuous feeding and continuous discharging, especially in the reaction involving gas production, can effectively export gas, avoid gas accumulation, and improve safety and reaction efficiency.

In order to monitor the amount of inert gas introduced into the continuous electrochemical reactor 10 in real time, in a preferred embodiment of the present application, the electrochemical reactor further includes an inert gas flowmeter 12, the inert gas flowmeter 12 and the inert gas inlet 117 are connected.

In the above-mentioned continuous electrochemical reactor 10, the structure and form of the temperature control device 20 are not particularly limited, as long as suitable reaction temperature conditions can be provided for the continuous electrochemical reactor 10, they are all applicable to the present application. In a preferred embodiment of the present application, the temperature control device 20 is a temperature control jacket, and the temperature control jacket includes a jacket cavity arranged around the electrochemical reactor and a jacket arranged on the side wall of the jacket cavity Inlet 201 and jacket outlet 202. Setting the reaction jacket can more conveniently and directly control the temperature conditions of the continuous reactor.

The specific arrangement positions of the jacket inlet 201 and the jacket outlet 202 are not limited, as long as the medium in the jacket can be effectively used for temperature control. In a preferred embodiment of the present application, the jacket inlet 201 is located at the lower half of the side wall of the jacket cavity, and the jacket outlet 202 is located at the upper half of the side wall of the jacket cavity. Through the lower inlet and upper outlet, sufficient heat exchange can be performed with the material in the continuous electrochemical reactor 10, and the temperature control efficiency is high.

In order to regulate the temperature control device 20 more accurately, in order to more accurately control the temperature of the continuous electrochemical reactor 10 . In a preferred embodiment of the present application, as shown in FIG. 2 , the continuous electrochemical reaction device further includes a temperature measuring device 30 , and the temperature measuring device 30 is connected to the product outlet 116 . A temperature measuring device 30 is provided at the product outlet 116, so that the temperature in the reactor can be accurately obtained in real time, so as to adjust and monitor the reaction temperature conditions.

In the above-mentioned continuous electrochemical reactor 10, the materials of the center electrode 13 and the peripheral electrode 14 are not particularly limited, as long as they can carry out an electrochemical reaction. In a preferred embodiment of the present application, the material of the central electrode 13 and the peripheral electrode 14 is selected from any one of the following: graphite, Pt, Cu, Ag, Zn, Pb, Au, Fe, Ti, Ni, alloy or the above Oxides of various metals; the material of the side wall 112 of the reactor is metal material, polytetrafluoroethylene, PP or metal material sprayed with polytetrafluoroethylene.

The above-mentioned various electrode materials have different specific applicable electrode materials according to different electrochemical reactions. When the above-mentioned metal oxide is used as an electrode, it refers to metal oxides such as PbO ₂ , CuO, Ag ₂ O, Fe ₂ O ₃ , TiO ₂ , and NiO. Correspondingly, the material of the above-mentioned reactor side wall 112 can also be reasonably selected according to actual needs, for example, it can be a metal material, such as iron or stainless steel. The metal reactor side wall 112 itself can also be used as an electrode. It can also be made of non-metallic materials, such as Teflon or PP. It can also be a metal material sprayed with polytetrafluoroethylene.

In the above-mentioned continuous electrochemical reactor 10, the shapes of the central electrode 13 and the peripheral electrode 14 are not particularly limited. In a preferred embodiment of the present application, the central electrode 13 is in the shape of a rod or a mesh; Flakes or nets. The mesh shape is similar to the screen window, but the hole and size are set according to the needs, and it can also be set to a specific character.

Electrode spacing is one of the important parameters to be considered when designing electrochemical reactors, and electrode spacing can affect the efficiency of electrode reaction. In a preferred embodiment of the present application, the distance between the central electrode 13 and the peripheral electrode 14 is 0.1-5 cm. In another preferred embodiment of the present application, the distance between the central electrode 13 and the peripheral electrode 14 is 0.5-3 cm. The electrode spacing within the above preferred range is small, the electrolysis voltage is reduced, and the energy consumption is thereby reduced, and the reaction efficiency is high under the same electric energy.

In a preferred embodiment of the present application, a diaphragm is provided between the central electrode 13 and the peripheral electrode 14 . The setting of the diaphragm helps to avoid the mixing of the products produced by the bipolar, prevent the occurrence of side reactions and secondary reactions that affect the product purity, yield and current efficiency, and avoid dangerous and safety accidents (such as gas mixture explosion).

The specific shape of the above-mentioned continuous electrochemical reactor 10 has no influence on the reaction, so the shape is not particularly limited. In a preferred embodiment of the present application, the reaction chamber 111 is a cylinder, and the length-diameter ratio of the reaction chamber 111 is 3-300:1. In another preferred embodiment of the present application, the length-diameter ratio of the reaction chamber 111 is 10-100:1. Controlling the aspect ratio of the reaction chamber 111 within the above range has beneficial effects such as avoiding back-mixing and reducing side reactions.

The above-mentioned continuous electrochemical reaction device participates in the electrochemical reaction, so it also needs to be connected to a power source. In a preferred embodiment of the present application, the continuous electrochemical reaction device further includes an electrolytic reaction power source 60 electrically connected to the central electrode 13 and the peripheral electrode 14 , and the electrolytic reaction power source 60 is a DC voltage-stabilized and constant-current reaction power source. The DC voltage-stabilized and constant-current reaction power supply has high stability, which in turn makes the reaction conditions relatively stable.

In actual production and application of the above-mentioned continuous electrochemical reaction device, one or more of the above-mentioned continuous electrochemical reactors 10 may be used according to different electrochemical reaction requirements. In a preferred embodiment of the present application, there are multiple continuous electrochemical reactors 10, and the multiple continuous electrochemical reactors 10 are arranged in series or in parallel.

The continuous electrochemical reactor 10 in the above-mentioned continuous electrochemical reaction device can realize continuous electrochemical reaction in that it can continuously feed and discharge continuously. There are many ways to specifically realize continuous feeding and continuous discharging. For example, a power conveying device can be provided at the raw material inlet 115, or a material extraction power device can be provided at the product outlet 116. In summary, the continuous electrochemical reaction of the material within the electrochemical reactor is achieved by the pressure difference between the feed inlet 115 and the product outlet 116 . In a preferred embodiment of the present application, the continuous electrochemical reaction device further includes a raw material device 40 and a raw material power conveying device 50 , and the raw material device 40 communicates with the continuous electrochemical reactor 10 through the raw material power conveying device 50 .

In another typical embodiment of the present application, a method for continuously oxidizing a thioether-based substrate to sulfone is provided, the method comprising continuously feeding the thioether-based substrate into any one of the above-mentioned continuous electrochemical reaction devices Oxidize. The above continuous method greatly improves the reaction efficiency of continuous oxidation of thioether substrates to sulfones.

In the above-mentioned method for continuous oxidation of thioether substrates to sulfones, the conditions for terminating the reaction are the same as those for existing batch reactions. Specifically, in a preferred embodiment of the present application, the method further includes sampling and detection at the product outlet of the continuous electrochemical reaction device, so as to control the molar ratio of the raw material to the product of the thioether substrate to be less than 1%. Specifically in actual operation, by detecting the molar ratio of raw materials in the effluent liquid from the product outlet, according to this ratio, the flow rate parameters and current density parameters of the raw materials continuously fed into the continuous electrochemical reaction device are continuously adjusted, and the molar ratio of raw materials and products is finally realized. When the ratio is less than 1%, the continuous reaction system is stable. In the continuous production process, by intermittently detecting the molar ratio of raw materials in the product liquid at the product outlet, and controlling it within the above ratio range, the stability of the reaction system can be monitored in real time to ensure the unity of the continuous reaction product. Reduce the production of by-products. A specific way to monitor the molar ratio of the substrate raw material in the product can be performed by mass spectrometry.

In order to further improve the reaction efficiency of continuous oxidation of sulfide substrates to sulfones, in a preferred embodiment of the present application, the central electrode in the continuous electrochemical reaction device is a graphite electrode, and the peripheral electrode is zinc or copper. Electrode species of this class have high electrochemical reaction efficiency for the continuous oxidation of thioether-based substrates to sulfones.

The beneficial effects of the present application will be further described below with reference to specific embodiments.

Examples 1-6: Oxidation of thioether substrates to sulfones

The continuous electrochemical reaction information of Examples 1 to 6 is shown in Table 1 below, wherein the central electrode is a graphite electrode, and the peripheral electrode is a zinc electrode.

Example 1

Dissolve 500g of raw materials in 10L of 0.4M HCl aqueous solution, pre-inject the electrolyte of 0.4M HCl to fill the electrolytic cell, energize the direct current of 19.8A, and use a peristaltic pump to feed the material into the reactor at a speed of 13.3mL/min, After passing through three reactors connected in series in sequence, after 50 minutes, sampling and testing at the outlet end showed that the molar ratio of raw materials to products was less than 1%. The current efficiency is 60%, and the product separation yield is 95%.

Example 2

Dissolve 500g of raw materials in 10L of 0.4M HCl aqueous solution, pre-inject the electrolyte of 0.4M HCl to fill the electrolytic cell, energize the direct current of 48.4A, the current density is 70mA/cm ² , and use a peristaltic pump at a speed of 32.5mL/min The material is poured into the reactor, and passes through three reactors in series in sequence. After 50 minutes, sampling is carried out at the outlet for detection, and the molar ratio of the raw material to the product is less than 1%. The current efficiency is 58%, and the product separation yield is 92%.

Example 3

Dissolve 500g of raw materials in 10L of 0.4M HCl aqueous solution, pre-inject 0.4M HCl electrolyte to fill the electrolytic cell, energize 11A direct current, current density 70mA/cm ² , and use a peristaltic pump to beat at a speed of 7.39mL/min. The material is fed into the reactor and passes through three reactors in series in sequence. After 50 minutes, sampling is carried out at the outlet end to detect that the molar ratio of the raw material to the product is less than 1%. The current efficiency is 52%, and the product separation yield is 86%.

Example 4

Dissolve 500g of raw materials in 10L of 0.4M HCl aqueous solution, pre-inject 0.4M HCl electrolyte to fill the electrolytic cell, energize 88A direct current, current density 70mA/cm ² , and use a peristaltic pump to beat at a speed of 59.1mL/min. The material is fed into the reactor and passes through three reactors in series in sequence. After 50 minutes, sampling is carried out at the outlet end to detect that the molar ratio of the raw material to the product is less than 1%. The current efficiency is 55%, and the product separation yield is 88%.

The operation process of embodiment 5 and 6 is similar to above-mentioned embodiment, and concrete reaction conditions and reaction effect are shown in Table 1.

Table 1:

Comparative ratio:

Add 10g of thioether substrate and 100mL of 0.4M HCl solution to a 150mL open electrolytic cell, stir evenly, put two pieces of graphite electrodes 15*5cm ² in the electrolytic cell, the area of the immersed part is 12*5cm ² , the current density was 70mA/cm ² , the current was 4.2A, the reaction system was followed until the molar ratio of raw materials to product was less than 1%, the electrolysis time was 4.3h, the current efficiency was 50%, and the post-processing separation yield was 85%.

It can be seen that the continuous electrochemical reactor works continuously, the reactants continue to enter the reactor, the products continue to flow out, and the composition of the electrolyte changes continuously with its spatial position in the reactor, and each reactant has the same Therefore, the reaction efficiency is high.

From the above description, it can be seen that the above-mentioned continuous electrochemical reaction device of the present application of the present invention has achieved the following technical effects: (1) The unit reactor volume has a larger heat exchange area, which is especially suitable for large thermal effects. (2) The flow rate of the reactants in the reactor is fast and the processing time is short, which greatly reduces the volume of the equipment; (3) The electrode spacing is small, and the small electrode spacing reduces the electrolysis voltage, thereby reducing energy consumption; (4) Reaction The device adopts tubular electrodes, which can be used alone or in combination according to requirements, with convenient operation and management and strong flexibility; (5) simple structure, reducing fixed and operating costs, small footprint, and reduced investment costs.

Continuous feeding, continuous discharging, especially in the reaction involving gas production, effectively exporting gas, avoiding gas accumulation, high safety and high reaction efficiency. Continuous and efficient, reduce equipment volume and floor space, save operation time, and reduce labor intensity; avoid the disadvantages of uneven local reaction, many side reactions, resulting in unstable product quality; compared with intermittent operation, the reaction system is small, and it is easy to control temperature. High security.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims (18)

1. A continuous electrochemical reaction device, comprising:

a continuous electrochemical reactor (10) comprising a reactor body (11), the reactor body (11) having a reaction chamber (111), a central electrode (13) and a peripheral electrode (14) being disposed within the reaction chamber (111), the peripheral electrode (14) being disposed around the central electrode (13); and

a temperature control device (20), the temperature control device (20) being disposed around the reactor body (11);

the reactor body (11) further comprises:

an inert gas inlet (117), the inert gas inlet (117) being located at an upper half of the reactor sidewall (112) and above the product outlet (116); and

a tail gas outlet (118), the tail gas outlet (118) being located at an upper half of the reactor sidewall (112) and above the inert gas inlet (117);

the distance between the central electrode (13) and the peripheral electrode (14) is 0.5-3 cm, and the length-diameter ratio of the reaction cavity (111) is 10-100: 1.

2. continuous electrochemical reaction device according to claim 1, characterized in that said reactor body (11) comprises: the reactor comprises a reactor side wall (112), a reactor upper cover (113) and a reactor lower cover (114), wherein the reactor side wall (112), the reactor upper cover (113) and the reactor lower cover (114) enclose the reaction cavity (111), the reactor upper cover (113) covers the top of the reactor side wall (112), and the reactor lower cover (114) covers the bottom of the reactor side wall (112).

3. The continuous electrochemical reaction device according to claim 2, characterized in that the reactor side wall (112) and the reactor upper cover (113) are connected by an upper flange (101).

4. The continuous electrochemical reaction device according to claim 2, characterized in that the reactor side wall (112) and the reactor lower cover (114) are connected by a lower flange (102).

5. The continuous electrochemical reaction device according to claim 2, characterized in that the reactor body (11) further comprises:

a feedstock inlet (115), the feedstock inlet (115) being located in a lower half of the reactor sidewall (112); and

a product outlet (116), the product outlet (116) being located at an upper half of the reactor sidewall (112).

6. The continuous electrochemical reaction device according to claim 1, characterized in that the continuous electrochemical reactor (10) further comprises: an inert gas flow meter (12), the inert gas flow meter (12) in communication with the inert gas inlet (117).

7. Continuous electrochemical reaction device according to claim 1 or 2, characterized in that the temperature control device (20) is a temperature controlled jacket comprising a jacket cavity arranged around the continuous electrochemical reactor (10) and a jacket inlet (201) and a jacket outlet (202) arranged on the jacket cavity side wall.

8. The continuous electrochemical reaction device according to claim 7, wherein the jacket inlet (201) is located at a lower half of the side wall of the jacket cavity, and the jacket outlet (202) is located at an upper half of the side wall of the jacket cavity.

9. The continuous electrochemical reaction device according to claim 4, further comprising a temperature measuring device (30), wherein the temperature measuring device (30) is connected to the product outlet (116).

10. The continuous electrochemical reaction device according to claim 2, wherein the material of the central electrode (13) and the peripheral electrode (14) is selected from any one of the following: graphite, Pt, Cu, Ag, Zn, Pb, Au, Fe, Ti, Ni, alloy or metal oxide, wherein the metal oxide is PbO₂、CuO、Ag₂O、Fe₂O₃、TiO₂Or NiO; the material of reactor lateral wall (112) is the metal material of metal material, polytetrafluoroethylene, PP or spraying polytetrafluoroethylene, the metal material is iron or stainless steel.

11. The continuous electrochemical reaction device according to claim 1 or 2, characterized in that the central electrode (13) is shaped as a rod or a net; the peripheral electrode (14) is sheet-shaped or net-shaped.

12. Continuous electrochemical reaction device according to claim 1 or 2, characterized in that a separator is arranged between the central electrode (13) and the peripheral electrode (14).

13. The continuous electrochemical reaction device according to claim 1 or 2, further comprising an electrolysis reaction power supply (60) electrically connected to the central electrode (13) and the peripheral electrode (14), wherein the electrolysis reaction power supply (60) is a direct current voltage and current stabilization reaction power supply.

14. Continuous electrochemical reaction device according to claim 1 or 2, characterized in that said continuous electrochemical reactor (10) is in plurality, a plurality of said continuous electrochemical reactors (10) being arranged in series or in parallel.

15. The continuous electrochemical reaction device according to claim 1 or 2, further comprising:

a raw material device (40); and

the raw material power conveying device (50), and the raw material device (40) is communicated with the continuous electrochemical reactor (10) through the raw material power conveying device (50).

16. A method for the continuous oxidation of a thioether substrate to a sulfone, comprising continuously feeding the thioether substrate to a continuous electrochemical reaction apparatus according to any one of claims 1 to 15 for oxidation.

17. The method of claim 16, further comprising sampling the product outlet of the continuous electrochemical reaction apparatus to control the molar ratio of raw materials to product of the thioether substrate to be less than 1%.

18. The method according to claim 16, wherein the central electrode (13) in the continuous electrochemical reaction device is a graphite electrode and the peripheral electrode (14) is zinc or copper.

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