A plug flow reaction device for high pressure reaction process and its construction method

Abstract

The present invention belongs to the technical field of chemical reaction equipment, and specifically relates to a plug flow reaction device for high-pressure reaction processes and a construction method thereof. The plug flow reaction device comprises: at least one reaction unit, the reaction unit having a reaction unit inlet and a reaction unit outlet; the reaction unit having a spiral channel in a horizontal direction, the reaction material enters the spiral channel through the reaction unit inlet, and after a plug flow reaction is carried out in the spiral channel, is discharged through the reaction unit outlet. The plug flow reaction device and the construction method thereof described in the present application have the advantages of safety, high efficiency and low construction cost.

Description

Technical Field

[0001] The present invention belongs to the technical field of chemical reaction equipment, and specifically relates to a plug flow reaction device, and in particular to a plug flow reaction device for high-pressure reaction process and a construction method thereof. Background Art

[0002] At present, the domestic production of aryl or phenyl chlorosilane mainly adopts high-temperature gas phase condensation reaction method and direct fluidized bed process. The reaction temperature of these two processes is as high as 500 ℃ or more. It is not only necessary to use expensive high nickel-chromium alloy to manufacture reaction equipment, but also because it cannot avoid the generation of polychlorinated biphenyls (PCBs), resulting in a variety of reaction byproducts, product purification is difficult, and there are frequent pipeline coking and blockage failures and severe high-temperature chlorine corrosion, and the problem of high cost of repair and maintenance of reaction equipment. Among them, the direct fluidized bed process must use a metal catalyst to produce aryl or phenyl chlorosilane, which is more likely to generate PCBs and pollute the environment seriously. Therefore, when the chlorosilane products obtained by the above two processes are used to produce downstream end products, they must also be treated with sodium metal for a long time or other high-difficulty, high-cost, and high-risk processes to reduce the content of dangerous PCBs contained in the product to below 0.5ppm to meet international standards, otherwise the market is strictly restricted. In addition, there are currently also Grignard processes and sodium condensation processes to produce aryl or phenyl chlorosilane and its downstream products, but these processes also have the disadvantages of high risk, high cost, and difficulty in amplifying production capacity.

[0003] The study found that although the production of aromatic or phenyl chlorosilanes by high-pressure liquid-phase non-catalytic condensation reaction requires high-pressure conditions of 15 to 20 MPa, the reaction temperature is relatively low, which can be below 350°C. In addition, the reaction process produces few by-products, making the product easy to purify. At the same time, it can avoid the formation of highly toxic polychlorinated biphenyls, and the high-boiling by-products are easy to handle and utilize, with very little hazardous high-boiling slurry. In addition, this process can produce a large amount of aromatic hydrogen-containing dichlorosilane for the production of special silicone monomers. Especially when the reaction temperature is controlled below 330°C, the by-product aromatic hydrogen-containing dichlorosilane can be better produced, but the reaction speed will become very slow. If large-scale production is required, a very long thick-walled pipe reactor is required to achieve a plug flow reaction to obtain the necessary reaction conversion rate. However, because the reaction pipe must be resistant to hydrogen embrittlement and high-temperature chlorine corrosion, the manufacturing cost of the plug flow high-pressure reactor is very high. Therefore, the large-scale production of aromatic or phenyl chlorosilanes by high-pressure liquid-phase non-catalytic condensation reaction of chloroaromatic hydrocarbons and hydrogen-containing chlorosilanes has not yet been achieved in China. Similarly, the use of low-boiling-point boron trifluoride or boron trichloride to catalyze the dehydrogenation reaction of benzene and hydrogen-containing chlorosilanes under a high pressure of 10 MPa to synthesize aromatic or phenyl chlorosilanes also has the advantages of low reaction temperature, high yield, avoidance of polychlorinated biphenyls, and easy purification of the product. However, it also has the disadvantage of slow reaction speed. When using a tubular reactor, an auger, i.e., a screw conveyor, must be installed in the reaction tube to maintain the contact mass transfer effect between the gas catalyst and the reaction liquid. This requires a large amount of stainless steel, resulting in difficulty and high cost in constructing such a production device. In summary, due to the high-pressure risk in the reaction process, the high cost and difficulty of constructing the reaction device, high-pressure processes such as high-pressure liquid-phase non-catalytic condensation and catalytic dehydrogenation have always been difficult to adopt in industry to prepare chlorosilanes.

[0004] In existing reaction apparatuses, the use of a plug flow reactor is beneficial for improving the selectivity and conversion rate of high-pressure liquid-phase reactions for synthesizing aryl chlorosilanes. Its operation is smooth, continuous, and simple to operate, making it easy to ensure the safety of the high-pressure process. Typically, plug flow reactors for existing high-pressure reaction processes are implemented using tubular reactors, which improve heat exchange efficiency. For rapid reaction processes, this design helps reduce construction costs. However, when such tubular reactors are used in slow, high-pressure reaction processes, they place high demands on the equipment's materials and welding, require a high number of consumables, and are difficult to arrange compactly, resulting in high construction costs and high safety risks. Therefore, they are not suitable for high-pressure reaction processes and catalytic dehydrogenation methods for producing aryl or phenyl chlorosilanes.

[0005] In view of this, providing a safe, efficient, and low-cost plug-flow reactor and its construction method suitable for high-pressure reaction processes to produce aryl or phenylchlorosilanes is one of the technical problems that those skilled in the art urgently need to solve, in order to promote the development of high-pressure reaction processes for producing aryl or phenylchlorosilanes. Summary of the Invention

[0006] The purpose of the present invention is to address the above-mentioned technical problems and to provide a safe, efficient, low-cost plug-flow reactor and its construction method for producing chlorosilanes by a high-pressure reaction process.

[0007] In view of this, the present invention provides a method for constructing a plug flow reactor for a high-pressure reaction process, wherein the plug flow reactor comprises:

[0008] at least one reaction unit having a reaction unit inlet and a reaction unit outlet;

[0009] The reaction unit has a spiral channel in a horizontal spiral shape. The reaction material enters the spiral channel through the reaction unit inlet, undergoes plug flow reaction in the spiral channel, and is discharged through the reaction unit outlet.

[0010] Furthermore, the spiral channel is a spiral reaction channel extending along an Archimedean spiral or an equidistant spiral.

[0011] Furthermore, the spiral channel includes:

[0012] Equally spaced concentric multi-layered ring channels, wherein a blind plate is provided on a vertical surface of each concentric multi-layered ring channel, the blind plate being used to separate the same concentric multi-layered ring channel into non-connected circular ring channels, and a connecting port is provided on one side of the blind plate, the connecting port connecting adjacent inner and outer circular ring channels;

[0013] The reaction fluid flows through the concentric ring channels in sequence through the communication port, and flows toward the inner layer or the outer layer of the concentric multi-layer ring channels;

[0014] The reaction material fluids in adjacent inner and outer circular channels can flow in the same or opposite directions.

[0015] Furthermore, the spiral channel is manufactured by bending a straight tube with a circular or square cross section.

[0016] Furthermore, the reaction unit comprises:

[0017] Two spiral channels are arranged side by side, one of which is marked as a forward spiral channel and the other as a reverse spiral channel, the forward spiral channel and the reverse spiral channel are connected to each other, and the flow directions of the reaction materials in the forward spiral channel and the reverse spiral channel are opposite;

[0018] The reaction material enters the reaction unit through the reaction unit inlet, flows through the positive spiral channel and the reverse spiral channel in sequence to react, and then is discharged through the reaction unit outlet.

[0019] Furthermore, the cross-sections of the positive spiral channel and the reverse spiral channel are rectangular cross-sections with a width dimension greater than a height dimension.

[0020] Furthermore, the plug flow reaction device further comprises:

[0021] an inner cylinder arranged in a vertical direction;

[0022] An outer cylinder, which is arranged around the outer periphery of the inner cylinder;

[0023] The annular gap between the inner cylinder and the outer cylinder forms an annular gap channel, and the temperature control medium flows in the annular gap channel to control the temperature of the reaction unit;

[0024] The reaction materials and the temperature control medium both enter from the lower end of the plug flow reaction device, and then gradually move upwards and are discharged from the upper end of the plug flow reaction device.

[0025] Furthermore, the plug flow reaction device further comprises:

[0026] An upper head and a lower head are arranged at two ends of the inner cylinder opposite to each other;

[0027] The upper head and the lower head are flat heads or dished heads.

[0028] Furthermore, the inner cylinder is made of 316L or 304L stainless steel;

[0029] The outer cylinder is made of hydrogen embrittlement resistant carbon steel containing chromium and molybdenum elements, and 321 or 309 stainless steel is welded on its inner wall; or, the outer cylinder is a stainless steel / carbon steel composite cylinder prepared by explosive composite method.

[0030] Furthermore, the reaction unit comprises:

[0031] a spiral partition, which is spirally arranged in the reaction unit, and the spiral channel is formed by the curling of the spiral partition; the spiral partition located outside the reaction unit is called an outer partition, which constitutes the outer wall of the reaction unit;

[0032] The spiral baffle inside the reaction unit is made of a thin-walled stainless steel plate with a thickness of 1.5 to 3 mm.

[0033] The outer partition is made of a plate with a thickness of more than 15 mm, and the outer partition is made of a thick carbon steel plate with double-sided composite stainless steel.

[0034] Furthermore, the plug flow reaction device comprises:

[0035] A plurality of reaction units are stacked in a vertical direction and connected in series in sequence through the reaction unit inlet and the reaction unit outlet to form a reaction zone body of the plug flow reaction device.

[0036] A plug flow reaction device for a high-pressure reaction process, wherein the plug flow reaction device is a plug flow reaction device prepared according to the above-mentioned construction method.

[0037] The plug flow reaction device and the construction method thereof described in the present invention have the advantages of safety, high efficiency and low construction cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 Schematic diagram of the top view of the reaction unit of the present invention;

[0039] Figure 2 Schematic diagram of the structure of the plug flow reaction device of the present invention;

[0040] Figure 3 This is a process flow chart for producing chlorosilane by connecting multiple plug-flow reactors of the present invention in series;

[0041] Figure 4 A process flow chart of producing chlorosilane by catalytic dehydrogenation using multiple plug-flow reactors according to the present invention connected in series;

[0042] Figure 5 2 is another schematic top view of the reaction unit of the present invention.

[0043] The marks in the figure are:

[0044] 1. Reaction unit; 101. Positive spiral channel; 102. Anti-spiral channel; 103. Reaction unit inlet; 104. Reaction unit outlet; 105. Intersection area; 106. Spiral partition; 107. Outer partition; 2. Inner cylinder; 3. Outer cylinder; 4. Reaction material inlet; 5. Reaction material outlet; 6. Annular gap channel; 7. Temperature control medium inlet; 8. Temperature control medium outlet; 9. Bellows expansion joint; 10. Concentric multi-layer annulus; 11. Blind plate; 12. Connecting port. DETAILED DESCRIPTION

[0045] The following will be combined with the accompanying drawings in the embodiments of the present application to clearly describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field are within the scope of protection of this application.

[0046] In the description of this application, it should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to this application. For ease of description, the dimensions of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. Technologies, methods and equipment known to ordinary technicians in the relevant fields may not be discussed in detail, but where appropriate, the technologies, methods and equipment should be considered as part of the authorization specification. In all examples shown and discussed here, any specific values ​​should be interpreted as merely exemplary and not as limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0047] It should be noted that the terms "first," "second," etc. in the specification and claims of this application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way are interchangeable where appropriate, so that the embodiments of this application can be implemented in an order other than those illustrated or described herein, and that the objects distinguished by "first," "second," etc. are generally of the same type, and do not limit the number of objects. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0048] It should be noted that, in the description of this application, the directions or positional relationships indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, vertical, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description. Unless otherwise specified, these directional terms do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of this application; the directional terms "inside and outside" refer to the inside and outside relative to the outline of each component itself.

[0049] It should be noted that, in the present application, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in the opposite order according to the functions involved. For example, the described method may be performed in an order different from that described, and various steps may also be added, omitted, or combined. In addition, the features described with reference to certain examples may be combined in other examples.

[0050] A method for constructing a plug flow reactor for producing chlorosilanes using a high-pressure reaction process, the plug flow reactor comprising:

[0051] at least one reaction unit 1, wherein the reaction unit 1 has a reaction unit inlet 103 and a reaction unit outlet 104;

[0052] The reaction unit 1 has a spiral channel, which is the reaction pipe of the plug flow reaction device. The reaction materials enter the spiral channel through the reaction unit inlet 103, undergo plug flow reaction in the spiral channel, and are discharged through the reaction unit outlet 104.

[0053] Preferably, the spiral channel is a reaction channel extending in the vertical direction and being spiral in the horizontal direction.

[0054] As some embodiments of the present application, the reaction unit 1 includes two spiral channels arranged side by side in parallel, one of the spiral channels is recorded as a positive spiral channel 101, and the other is recorded as a reverse spiral channel 102, and the positive spiral channel 101 and the reverse spiral channel 102 are connected to each other; the reaction material enters the reaction unit 1 through the reaction unit inlet 103, flows through the positive spiral channel 101 and the reverse spiral channel 102 in sequence for reaction, and is discharged through the reaction unit outlet 104.

[0055] At this time, the structures of the forward spiral channel 101 and the reverse spiral channel 102 are similar to two spiral channels made by rolling two parallel plates.

[0056] In the present application, the shapes and spiral directions of the positive spiral channel 101 and the reverse spiral channel 102 are basically the same. The main difference is that the flow directions of the reaction materials in the positive spiral channel 101 and the reverse spiral channel 102 are different. In order to facilitate the clear description of this application, they are respectively referred to as the positive spiral channel 101 and the reverse spiral channel 102. When the reaction material moves in a clockwise or counterclockwise direction in the positive spiral channel 101, it will move in the opposite direction in the reverse spiral channel 102.

[0057] Furthermore, the plug flow reaction device comprises:

[0058] Multiple reaction units 1 are sequentially connected in series through the reaction unit inlet 103 and the reaction unit outlet 104 to form a reaction zone body of the plug flow reaction device.

[0059] As some embodiments of the present application, the reaction unit 1 is formed by rolling two vertically arranged parallel plates into two spiral channels, and the obtained positive spiral channel 101 and reverse spiral channel 102 extend in the vertical direction and are spiral in the horizontal direction.

[0060] Preferably, the reaction unit 1 is formed into two spiral channels by rolling two parallel plates along an Archimedean spiral or an equidistant spiral, so that the obtained positive spiral channel 101 and reverse spiral channel 102 also extend along the Archimedean spiral or the equidistant spiral.

[0061] The positive spiral channel 101 and the reverse spiral channel 102 have a central end close to the central area of ​​the reaction unit 1 and an edge end close to the edge of the reaction unit 1. The reaction unit inlet 103 is arranged at the central end of the positive spiral channel 101, and the reaction unit outlet 104 is arranged at the central end of the reverse spiral channel 102. The edge end of the positive spiral channel 101 and the edge end of the reverse spiral channel 102 are connected, and an intersection area 105 is formed at the connection between the positive spiral channel 101 and the reverse spiral channel 102. In this way, the movement trajectory of the reaction material in the reaction unit 1 is as follows: first, through The reaction unit inlet 103 enters the central end of the forward spiral channel 101, and then spirals forward along the extension path of the forward spiral channel 101 until it reaches the edge end of the forward spiral channel 101; as the channel direction changes, turbulence is generated in the intersection area 105 where the edge end of the forward spiral channel 101 and the edge end of the reverse spiral channel 102 are connected, and then spirals forward in the opposite direction along the extension path of the reverse spiral channel 102 until it reaches the central end of the reverse spiral channel 102, and then is discharged through the reaction unit outlet 104, completing the movement within the reaction unit 1 and entering the next reaction unit 1.

[0062] Preferably, the plug-flow reaction device comprises a plurality of reaction units 1, and the plurality of reaction units 1 are stacked vertically and connected in series.

[0063] Furthermore, the reaction unit 1 comprises:

[0064] The spiral partition 106 is disposed in a spiral shape in the reaction unit 1 . The spiral channels, such as the forward spiral channel 101 and the reverse spiral channel 102 , are formed by the curling of the spiral partition 106 .

[0065] Then, each reaction unit 1 will include two spiral partitions 106 that are substantially parallel to each other except for the central area and the edge area.

[0066] For the purpose of explaining the present application clearly, the spiral partition 106 located outside the reaction unit 1 is referred to as an outer partition 107 , which constitutes the outer wall of the reaction unit 1 .

[0067] Preferably, a plurality of reaction units 1 are stacked vertically in the plug-flow reactor, and the reaction unit outlet 104 of the lower reaction unit 1 is connected to the reaction unit inlet 103 of the upper reaction unit 1 to form a cylindrical reaction zone body.

[0068] Furthermore, the plug flow reaction device further comprises:

[0069] The inner cylinder 2 is arranged in the vertical direction;

[0070] The outer cylinder 3 is arranged around the outer periphery of the inner cylinder 2;

[0071] The annular gap between the inner cylinder 2 and the outer cylinder 3 forms an annular gap channel 6 , and a temperature control medium flows in the annular gap channel 6 to control the temperature of the reaction unit 1 .

[0072] As some embodiments of the present application, the inner cylinder 2 is a newly set inner cylinder wall that is different from the outer partition 107, and can also be directly integrally formed by stacking the outer partitions 107 together.

[0073] Furthermore, the reaction materials and the temperature control medium both enter from the lower end of the plug flow reaction device, and then gradually move upward and are discharged from the upper end of the plug flow reaction device.

[0074] Furthermore, a reaction material inlet 4 and a reaction material outlet 5 are respectively provided at the lower end and the upper end of the plug flow reaction device. The reaction material enters the reaction unit 1 on the lower layer from the lower end of the plug flow reaction device through the reaction material inlet 4, and then gradually moves upward and is discharged from the reaction material outlet 5 at the upper end of the plug flow reaction device.

[0075] Correspondingly, a temperature control medium inlet 7 and a temperature control medium outlet 8 are respectively provided at the lower end and the upper end of the plug flow reaction device. The temperature control medium enters the annular gap channel 6 from the lower end of the plug flow reaction device, and then gradually moves upward and is discharged from the temperature control medium outlet 8 at the upper end of the plug flow reaction device.

[0076] Preferably, the temperature control medium is chlorinated aromatic hydrocarbon.

[0077] Furthermore, the plug flow reaction device further comprises:

[0078] The upper head and the lower head are arranged at two ends of the inner cylinder 2 opposite to each other.

[0079] It should be noted that the upper head and the lower head can be flat heads, but because the pressure of the main body of the reaction zone is relatively high, the flat head needs to be very thick to withstand the pressure, which affects the economic efficiency. Therefore, the upper head and the lower head can also be dished heads. The dished head can withstand a large pressure difference to reduce the thickness of the upper head and the lower head.

[0080] During use, the reaction material may first enter the lower head, then enter the reaction unit 1 of the lowest layer through the reaction unit inlet 103, gradually move upward, and finally enter the upper head through the reaction unit outlet 104 of the uppermost reaction unit 1, and finally be discharged from the plug flow reaction device.

[0081] As some embodiments of the present application, when the upper head and the lower head are set, the reaction unit inlet 103 and the reaction unit outlet 104 can be set in the central area of ​​the reaction unit 1 in the aforementioned manner, or can be set at the edge ends of the positive spiral channel 101 and the reverse spiral channel 102. At this time, the edge ends of the positive spiral channel 101 and the reverse spiral channel 102 are not connected, and the center ends are connected. The reaction material first enters the reaction unit 1 through the reaction unit inlet 103 located at the edge end of the positive spiral channel 101, and then flows from the outside of the reaction unit 1 to the center along the positive spiral channel 101, and then flows from the center to the outside of the reaction unit 1 through the reverse spiral channel 102, and finally is discharged through the reaction unit outlet 104 set at the edge end of the reverse spiral channel 102.

[0082] The present application adopts a novel plug-flow reactor to reduce the construction cost of a high-pressure, slow, and low-thermal-effect reactor. When it is used to produce chlorosilanes, such as arylchlorosilanes or phenylchlorosilanes, especially when used in high-pressure processes such as high-pressure liquid-phase non-catalytic condensation and catalytic dehydrogenation to produce chlorosilanes, cheap stainless steel can be used to replace expensive materials, and the total amount of stainless steel used can be greatly reduced, while also greatly reducing the need for high-standard welding.

[0083] Of course, in addition to being used for the production of chlorosilanes, the plug flow reaction device described in this application can also be used for the production of other chemical products.

[0084] The plug flow reaction device described in the present application is compared with the existing reactor system for producing phenylchlorosilane by low-pressure and high-temperature gas-phase condensation method: the construction cost is similar, but the operation and maintenance costs of the plug flow reaction device described in the present application can be lower. Based on the improvement of the reactor structure made in the present application and combined with the design of the process flow, large-scale production can be easily achieved.

[0085] When in use, the plug flow reaction device can be quickly applied to the production process of large-scale production of aromatic chlorosilanes by high-pressure liquid-phase condensation reaction of chloroaryl hydrocarbons and hydrogen-containing chlorosilanes. Because its chemical reaction process releases less heat, the reaction speed is slow, and the reaction heat is easy to remove. Figures 1-2 When the plug flow reactor shown in the figure performs a reaction, the multiple reaction units in the plug flow reactor can be connected in series from bottom to top to obtain an ultra-long flow channel to meet the residence time required for the slow reaction, thereby avoiding the problem of compact arrangement of ultra-long tubular reactors.

[0086] The realization of such a horizontal spiral channel is based on the same principle as that of a spiral plate heat exchanger. The cross sections of the positive spiral channel 101 and the reverse spiral channel 102 can be square to save design materials and reduce flow resistance.

[0087] Preferably, it is more beneficial to optimize mass transfer that the forward spiral channel 101 and the reverse spiral channel 102 adopt rectangular cross-sections in which the width dimension in the horizontal direction is larger than the height dimension in the vertical direction.

[0088] In addition, a shaftless auger ribbon can be installed in the spiral channel of a large-capacity plug flow reaction device to enhance the mass transfer efficiency of the reaction fluid. A auger ribbon may not be installed in the spiral flow channel of a small-capacity plug flow reaction device.

[0089] As some embodiments of the present application, the outer partition 107 is cylindrical and is made of a plate with a thickness of more than 15 mm, so that it can withstand a large pressure difference and has higher safety; at the same time, the outer partition 107 can be made of a thick carbon steel plate with double-sided composite stainless steel to reduce costs, and the spiral partition 106 located inside the reaction unit 1 needs to withstand a very small pressure difference and can be made of a thin-walled stainless steel plate of 1.5 to 3 mm.

[0090] As some embodiments of the present application, only the two reaction units 1 at the top and bottom respectively must withstand a high pressure difference, and therefore need to be manufactured using thick plates. The pressure difference borne by the remaining reaction units 1 is relatively small, and their thickness can be appropriately thinned.

[0091] As some embodiments of the present application, for a small-capacity plug-flow reactor, one of the simpler and more efficient methods for making the positive spiral channel 101 and the reverse spiral channel 102 is to directly use a standard stainless steel square straight tube with a thickness of 3 mm through a CNC roll-bending machine to obtain the main bodies of the middle areas of the precise-formed positive spiral channel 101 and the reverse spiral channel 102, respectively. However, due to the excessive distortion of the central part of the spiral channel, it is necessary to weld a steel plate forming part and then weld it to the main body formed by rolling a straight square tube to obtain a spiral channel forming part. For details, please refer to the precision equidistant spiral forming process achieved by the variable curvature CNC roll-bending machine of Guangzhou Gaopu Machinery Technology Co., Ltd. The two spiral channel forming parts obtained are then arranged in adjacent unit layers above and below for cross stacking, and the gaps at the stacking are sealed and fixed, thereby doubling the number of spiral channels closed around the periphery. The process is then completed by welding and sealing the local structure, such as the butt welding with the outer partition 107, the structural sealing of the intersection area 105, and the structural sealing of the reaction unit inlet 103 and the reaction unit outlet 104 at the center. The outer partition 107 can be realized as an integral pressure-resistant cylinder specially processed in sections, avoiding the large number of high-demand thick welds required for step-by-step butt welding. The welding strength requirements of the step-by-step butt welding with the spiral channel forming parts are low, and laser welding can be used for rapid construction. The spiral channels obtained by this layer-by-layer processing method are separated by only thin metal walls, which can easily transfer heat outward or inward. In this way, the walls of all spiral channels will be honeycomb-shaped and cross-interconnected, and form an integrated reaction zone main assembly with the outer partition 107. Its structure is stable and rigid, which can prevent serious vibration damage caused by gas-liquid mixing.

[0092] As some embodiments of the present application, the annular gap of the annular gap channel 6 has an annular gap width of 10 to 20 mm, which allows high-pressure liquid chloroaromatic hydrocarbons to flow and carry away the reaction heat emitted from the wall of the inner cylinder 2.

[0093] Furthermore, since the reaction temperature is below 350°C, the components of the inner cylinder 2 can be made of inexpensive stainless steel, such as 316L, to withstand long-term chlorine corrosion and hydrogen embrittlement. The outer cylinder 3, on the other hand, needs to withstand the high temperatures and pressures within the reactor. Its design can be based on materials selected from hydrogenation reactors in petrochemical and coal chemical industries. For example, the main body of the outer cylinder 3 is made of hydrogen-embrittlement-resistant carbon steel containing chromium and molybdenum, and its inner wall is welded with 321 or 309 stainless steel to meet the long-term resistance requirements to hydrogen embrittlement and chlorine corrosion.

[0094] Therefore, the present application can reduce the construction cost of a high-pressure, slow, and low-thermal-effect reaction device by adopting a new plug flow reactor. When it is used to produce aromatic chlorosilanes or phenylchlorosilanes, cheap stainless steel materials, such as 304 and 316 stainless steel, can be selected to replace expensive materials such as high nickel-chromium alloys used in existing reactors, and the amount of stainless steel used can be greatly reduced, thereby reducing the overall cost of the plug flow reaction device; at the same time, the plug flow reaction device described in the present application can also greatly reduce the need for high-standard welding, and its construction cost is similar to that of the reactor system for producing phenylchlorosilane by low-pressure and high-temperature gas phase condensation method, but the operation and maintenance costs of the plug flow reaction device described in the present application are lower, and it is easy to realize large-scale production equipment through reactor structure optimization and process flow design coordination.

[0095] As some embodiments of the present application, a bellows expansion joint 9 is provided in the plug-flow reactor to compensate for the effects of asynchronous thermal expansion of the inner and outer cylinders and ensure the connection safety of the reactant outlet pipe.

[0096] Furthermore, since the material pressure in the inner cylinder 2 is higher than the pressure in the annular channel 6, in order to reduce the pressure difference borne by the outer partition 107, the outer partition 107 is used. Figure 3 The process flow shown is used for production. In this process, the reaction unit uses a high-boiling-point reaction raw material, chloroaromatic hydrocarbon, to circulate in large flow within the annular gap channel 6 to absorb the reaction heat and maintain a stable reaction temperature. Priority is given to using downstream heat exchange to minimize the pressure difference on the outer partition 107, and the reaction heat is utilized through an external heat exchanger system. In addition, a design scheme can be used to connect multiple plug flow reactors of the same type in series to meet production capacity requirements. Each plug flow reactor uses spiral channels of different cross-sectional sizes according to the different gas-liquid flow loads, optimizing the working conditions of the spiral channels in each plug flow reactor and avoiding the problem of excessive size and weight of the plug flow reactor being difficult to transport by road. At the same time, a sleeve heat exchanger is set on the material flow pipeline between the connected plug flow reactors to optimize temperature control. A safety pressure relief control device is set at the material outlet pipe at the top of each plug flow reactor. In the event of an accident, the internal pressure of the plug flow reactor can be quickly and controllably reduced and the material therein can be discharged to the accident storage tank condensation collection system for treatment. Similarly, an emergency discharge line is designed for the material inlet pipe at the bottom of each plug flow reactor. A high-pressure, double-tube heat exchanger is installed on the material inlet pipe for heat exchange, allowing the material to cool under high pressure before being discharged to the emergency storage tank, thereby reducing the risk of accident handling. For plug flow reactors connected in series, backup lines and valves are installed, allowing a faulty plug flow reactor to be isolated and handled separately, while the remaining plug flow reactors can continue to operate in series, thus reducing accident handling costs.

[0097] As some embodiments of the present application, the above-mentioned plug flow reaction device can also be used in combination with the attached Figure 4 The process flow design shown makes the above-mentioned plug flow reaction device suitable for using benzene or aromatic hydrocarbons and hydrogen-containing chlorosilanes as raw materials, and using boron trifluoride or boron trichloride as a catalyst to carry out catalytic dehydrogenation reaction to produce phenyl or aryl chlorosilanes. Because the reaction rate of this high-pressure gas-liquid phase is very slow and it is a weakly endothermic reaction, the raw material benzene or aromatic hydrocarbons with a higher boiling point can be used to carry heat and circulate at a high flow rate in the annular gap channel 6 of the plug flow reaction device, and the heat required for the reaction is provided to the reactants through heat conduction from the side wall of the inner cylinder 2.

[0098] In fact, although the use of boron trifluoride catalyst can effectively reduce the reaction temperature, due to the low boiling point of boron trifluoride and the reaction will generate hydrogen that is difficult to condense, the catalyst is easily carried away by the hydrogen. Conventional methods are difficult to achieve low-cost and long-term contact between the catalyst and the reactants. Therefore, the process of using boron trifluoride catalyst to produce phenylchlorosilane has not been reported to be used in the production process.

[0099] However, in the present application, by using an ultra-long horizontal spiral flow channel as the main body of the reaction zone, for a small-capacity plug-flow reactor, a rectangular flow channel section with a height less than the width can be used to allow the high-pressure reaction gas-liquid mixture to continuously turn, flip, and entrain during flow to form a continuous turbulent mixing. For a large-capacity plug-flow reactor, a horizontal spiral flow channel with a square cross-section is used, and a shaftless auger is installed in the horizontal spiral flow channel to enhance the mixing effect, avoid the separation problem of reactants and catalysts, and enable the normal use of this low-boiling-point boron trifluoride catalyst. Its catalytic effect is better than that of boron trichloride. This efficient mixing and mass transfer capability helps avoid the use of high reaction temperatures, thereby improving reaction selectivity. In addition, Figure 4 The process also enables low-cost recycling and reuse of the boron trifluoride catalyst.

[0100] Furthermore, tubular reactors typically require complex reinforcement and fixing measures to suppress vibration damage caused by gas-liquid mixing. Furthermore, the use of tubular reactors in large, slow-reaction, high-pressure production facilities often incurs significant safety and security costs, as the reactor system must accommodate hundreds of tons of high-temperature, high-pressure hazardous materials during operation. The spiral channel reaction structure in the plug-flow reactor provided by the present invention offers excellent rigidity, effectively preventing the violent vibrations caused by gas-liquid mixing and significantly reducing safety and security costs.

[0101] Furthermore, both high-pressure liquid-phase condensation and catalytic dehydrogenation processes for producing arylchlorosilanes typically generate difficult-to-condense gases during the reaction, making mixed gas-liquid flow inevitable. Condensation and catalytic dehydrogenation each offer complementary advantages, and their combined use in large-scale phenylchlorosilane production facilities can yield optimal economic benefits.

[0102] For example, five plug-flow reactors (each with an outer diameter of 2000 mm, a weight of 220 tons, and a design pressure of 18 MPa) are connected in series to create a 20,000-ton / year high-pressure liquid-phase condensation system for synthesizing phenylchlorosilanes. This system can produce nearly 6,000 tons / year of phenylhydrodichlorosilane as a byproduct, which can be used to produce vinylphenyldichlorosilane and other specialty phenylchlorosilanes. However, this system also produces a large amount of benzene containing trace amounts of chlorosilanes. This byproduct is difficult to market and handle, but it is well-suited as a feedstock for the catalytic dehydrogenation process to synthesize phenylchlorosilanes. Accordingly, a 50,000-ton / year phenylchlorosilane synthesis system using a catalytic dehydrogenation process was constructed by connecting five plug-flow reactors (each with an outer diameter of 2800 mm, a weight of 280 tons, and a design pressure of 12 MPa) in series. This system can primarily produce methylphenyldichlorosilane using relatively low-purity monomethylhydrogenated dichlorosilane as a raw material, or primarily produce diphenyldichlorosilane using relatively low-purity dichlorodihydrosilane, a by-product of the cold hydrogenation of silicon tetrachloride. This integrated process allows the utilization of byproduct benzene, enabling large-scale, low-cost, clean production of various phenylchlorosilanes with the highest market demand. It should be noted that the reactor pressure and temperature used in the catalytic dehydrogenation process are significantly lower than those used in the high-pressure liquid-phase condensation process. Therefore, the catalytic dehydrogenation process can utilize a thinner-walled outer cylinder 3 to reduce weight. Furthermore, the outer cylinder 3 can be manufactured using a low-cost stainless steel / carbon steel composite material using the explosive lamination method. Furthermore, the inner cylinder 2 assembly can be constructed from cheaper stainless steel, such as 304L, to reduce manufacturing costs, making this process more suitable for high-capacity plants.

[0103] As some other embodiments of the present application, Figure 5 As shown, the spiral channel in the reaction unit 1 is composed of concentric multi-layered ring channels 10 with equal width intervals to achieve the same mass transfer function. A blind plate 11 is set on the vertical surface of each concentric multi-layered ring channel 10. The blind plate 11 separates the same concentric ring channel into unconnected circular ring channels, and a connecting port 12 is set on one side of the blind plate 11. The connecting port 12 connects the adjacent inner and outer layers of the circular channels, so that the spiral channel is spiral-shaped as a whole. The reaction fluid can flow through each layer of the concentric multi-layered ring channel in sequence through the connecting port 12, gradually flowing to the inner layer or the outer layer of the concentric multi-layered ring channel 10. At this time, the reaction unit inlet 103 and the reaction unit outlet 104 of the upper and lower adjacent reaction units 1 are respectively at the blind plate 11 of the outermost circular channel or at the center of the innermost circular channel, so that the adjacent two layers of circular channels can achieve channel series connection.

[0104] Furthermore, the positions of the blind plate 11 and the communication port 12 can be adjusted so that the reaction material fluids in adjacent inner and outer circular channels flow in the same or opposite directions. Preferably, the positions of the blind plate 11 and the communication port 12 can be adjusted so that the reaction material fluids in adjacent inner and outer circular channels flow in opposite directions, so that the fluids in adjacent circular channels can achieve countercurrent heat exchange through the wall surface to reduce the reaction temperature difference.

[0105] For the above-mentioned plug-flow reaction device with concentric multi-layer ring channels 10, for reactors with small production capacity, a horizontal spiral channel unit can also be constructed by using a rolling machine to process rectangular tubes to reduce the construction difficulty. For reactors with large production capacity, thin steel plates are cut and blanked, and single-ring channel units with multi-series and standardized structures are processed in batches. Then, single-ring channel units of different series are cross-stacked and welded to form the structure of the inner cylinder 2 in the plug-flow reaction device. This processing method facilitates the installation of a shaftless spiral auger in the horizontal annular flow channel to optimize the mixing and mass transfer of the reaction fluid, thereby enhancing the operating reliability of the large-capacity reactor.

[0106] The above-mentioned plug-flow reaction device structures have modular characteristics, so the inner cylinder 2 components and the outer cylinder 3 components can be manufactured in independent sections to improve production efficiency. They are then transported to the chemical plant site for welding and assembly, thus avoiding the transportation and lifting difficulties of building overweight large reactors. They can be used to build devices with an annual production capacity of more than 100,000 tons.

[0107] As some other embodiments of the present application, the present application also discloses a method for constructing another plug flow reaction device, which has the advantage of being applicable to the production of phenyl or aryl chlorosilane products with smaller production capacity requirements, such as ethylphenyldichlorosilane and methylchlorophenyldichlorosilane for the production of special lubricants. The plug flow reaction device described in the present embodiment adopts a small-diameter round tube or a small-section square tube to manufacture a spiral channel. This pipeline has a strong ability to withstand internal and external pressures, and can avoid the use of an inner cylinder 2 to protect it. Standard stainless steel straight pipes of the same specifications are used for bending to obtain the positive spiral channel 101 and the reverse spiral channel 102 of the reaction unit 1. Afterwards, the two spiral channels are arranged in a tight cross-section in the same plane by assembling a mold and a fixed mold, and then a sealing and welding structure is constructed at both ends to obtain an ultra-long spiral channel of a flow similar to the aforementioned. This construction method makes the outer wall of the spiral channel contact with the inner wall of the reactor outer cylinder 3 and weld to form a reliable fixation, thus canceling the structure of the annular gap channel 6 of the previous method to make the plug flow reaction device, but there is a network of gaps between the spiral channels to realize the heat exchange function. For example, according to the reaction temperature and pressure, heat absorption or heat release characteristics, suitable materials can be selected to vaporize and absorb heat or condense and release heat in the gap space network to control the reaction temperature. The material used for this heat exchange is preferably one of the reaction raw materials, or other safe materials that can be mixed and compatible with the reaction raw materials. The specific selection criteria of the heat exchange material is to minimize the pressure difference and reaction temperature difference of the spiral channel wall, thereby facilitating the stability of the reaction temperature. Accordingly, the process flow adopted by the preparation method of the plug flow reaction device must also be provided with a pressure difference limiting safety protection system to prevent the spiral channel from being damaged. The plug flow reaction device constructed using this method has the least welding workload, the highest internal space utilization rate, and can reduce the number of reactors in series, but its requirements for pipe quality and welding quality are improved.

[0108] In addition, the present application also provides a plug flow reaction device for high-pressure reaction process, and the plug flow reaction device is prepared according to the above-mentioned construction method.

[0109] At present, domestically produced high-safety, leak-free high-pressure pumps, such as hydraulic metal diaphragm pumps, can meet the requirements of continuously and safely pumping the reaction raw materials of high-pressure processes into high-pressure reactor systems. China has realized inexpensive laser welding processes for efficient welding of thin-walled metal materials, and used CNC laser cutting to solve the problem of cutting and blanking metal sheets with complex shapes. A new CNC rolling machine has been used to realize a large-scale, high-precision Archimedean equal-pitch spiral forming process. A surfacing composite process has also been realized to reduce the manufacturing cost of large-scale hydrogenation reactors with high temperature and high pressure in the presence of hydrogen, and such extra-large reactors can be welded on site, which greatly reduces the cost of developing new plug flow reactors for the continuous production of aromatic chlorosilanes in high-pressure liquid-phase reaction processes, providing basic technical support for the construction of the plug flow reactor described in this application, making it easy to achieve.

[0110] In summary, the plug flow reactor for high-pressure reaction processes and the method for constructing the same described in this application have the following advantages:

[0111] First, the reaction unit 1 described in the present application is designed to have a compact horizontal flow spiral channel as the main reaction zone by using the principles of Archimedean spiral, equidistant spiral, and equidistant concentric circle. A shaftless auger belt can also be installed in the horizontal flow spiral channel to achieve a plug flow reaction function that maintains gas-liquid mixed flow, which is very beneficial for improving the reaction selectivity and conversion rate of high-pressure liquid-phase synthesis of arylchlorosilanes.

[0112] Second, the plug-flow reactor described in the present application uses thin metal walls as the main body to construct a spiral channel for the horizontal flow of reactants in a high-pressure gas-liquid mixture, making the spiral channel easy to efficiently process and significantly reducing the cost of the device.

[0113] Third, the plug-flow reactor described in this application has good structural seismic performance, can ensure long-term safe operation, and can replace high-temperature gas-phase condensation methods to achieve high-capacity production equipment, meeting the requirements of process environmental protection, improving product quality and reducing production costs.

[0114] Fourth, the plug flow reactor described in this application adopts a specific process flow to ensure the safety of the internal structure of the reactor;

[0115] Fifth, the plug flow reactor described in this application can realize an efficient boron trifluoride catalytic dehydrogenation process to produce arylchlorosilanes to improve economic efficiency. Its process flow makes the catalyst easy to separate and can realize the recycling of the catalyst;

[0116] Sixth, the plug flow reactor described in this application can use high-pressure liquid phase non-catalytic condensation and catalytic dehydrogenation processes to jointly build a large-scale phenylchlorosilane production plant to improve economic efficiency;

[0117] Seventh, the use of the plug flow reaction device and its construction method described in the present application can avoid the use of expensive metal materials and significantly reduce the amount of metal materials used, greatly reducing the construction cost of the reaction device for producing phenylchlorosilane by high-pressure liquid phase reaction of hydrogen-containing chlorosilane, and can eliminate the high-temperature gas phase condensation method and direct method for producing phenylchlorosilane with poor product quality, pollution and high cost, which not only achieves large-scale, low-cost and clean production, but also helps to expand product types and improve economic benefits.

[0118] The embodiments of the present application are described above in conjunction with the accompanying drawings. Unless there is a conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of this application, ordinary technicians in this field can also make many forms without departing from the purpose of this application and the scope of protection of the claims, all of which are within the protection of this application.

Claims

1. A plug flow reactor for high pressure reaction process, characterized in that: The plug flow reaction device comprises: A plurality of reaction units (1), each having a reaction unit inlet (103) and a reaction unit outlet (104), the plurality of reaction units (1) being stacked in a vertical direction, and the plurality of reaction units (1) being sequentially connected in series through the reaction unit inlet (103) and the reaction unit outlet (104), thereby forming a reaction zone body of a plug-flow reaction device; The reaction unit (1) has a spiral channel in a horizontal spiral shape, and the reaction material enters the spiral channel through the reaction unit inlet (103), undergoes plug flow reaction in the spiral channel, and is discharged through the reaction unit outlet (104); The reaction unit (1) comprises: Two spiral channels are arranged side by side, one of which is designated as a positive spiral channel (101) and the other as a negative spiral channel (102), wherein the positive spiral channel (101) and the negative spiral channel (102) are connected to each other, and the flow directions of the reaction materials in the positive spiral channel (101) and the negative spiral channel (102) are opposite; The reaction material enters the reaction unit (1) through the reaction unit inlet (103), flows through the positive spiral channel (101) and the reverse spiral channel (102) in sequence, reacts, and is discharged through the reaction unit outlet (104); The reaction unit inlet (103) is arranged at the central end of the positive spiral channel (101), the reaction unit outlet (104) is arranged at the central end of the reverse spiral channel (102), and the edge end of the positive spiral channel (101) and the edge end of the reverse spiral channel (102) are connected; Alternatively, the reaction unit inlet (103) and the reaction unit outlet (104) are arranged at the edge ends of the positive spiral channel (101) and the reverse spiral channel (102). In this case, the edge ends of the positive spiral channel (101) and the reverse spiral channel (102) are not connected, but the center ends are connected; The cross-sections of the positive helical channel (101) and the reverse helical channel (102) are rectangular cross-sections with a width dimension greater than a height dimension.

2. The plug flow reactor according to claim 1, characterized in that: The spiral channel is a spiral reaction channel extending along an Archimedean spiral or an equidistant spiral.

3. The plug flow reactor according to claim 1, characterized in that: The plug flow reaction device further comprises: An inner cylinder (2) arranged in a vertical direction; An outer cylinder (3) arranged around the periphery of the inner cylinder (2); The annular gap between the inner cylinder (2) and the outer cylinder (3) forms an annular gap channel (6), and a temperature control medium flows in the annular gap channel (6) to control the temperature of the reaction unit (1); The reaction materials and the temperature control medium both enter from the lower end of the plug flow reaction device, and then gradually move upwards and are discharged from the upper end of the plug flow reaction device.

4. The plug flow reactor according to claim 3, characterized in that: The plug flow reaction device further comprises: An upper head and a lower head, which are arranged oppositely at two ends of the inner cylinder (2); The upper head and the lower head are flat heads or dished heads.

5. The plug flow reactor according to claim 3, characterized in that: The inner cylinder (2) is made of 316L or 304L stainless steel; The outer cylinder (3) is made of hydrogen embrittlement-resistant carbon steel containing chromium and molybdenum elements, and 321 or 309 stainless steel is welded on its inner wall; or, the outer cylinder (3) is a stainless steel / carbon steel composite cylinder made by explosive composite method.

6. The plug flow reactor according to claim 2, characterized in that: The reaction unit (1) comprises: a spiral partition (106) disposed in a spiral shape in the reaction unit (1), wherein the spiral channel is formed by the curling of the spiral partition (106); the spiral partition (106) located outside the reaction unit (1) is referred to as an outer partition (107), which constitutes the outer wall of the reaction unit (1); The spiral partition (106) located inside the reaction unit (1) is made of a thin-walled stainless steel plate with a thickness of 1.5 to 3 mm; The outer partition (107) is made of a plate with a thickness of more than 15 mm, and the outer partition (107) is made of a thick carbon steel plate with double-sided composite stainless steel.

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