Efficient continuous flow kettle type module reaction device

Abstract

The invention discloses an efficient continuous flow kettle type module reaction device which comprises N standard kettle type modules which are connected in series in a multi-stage manner, the standard kettle type module comprises a metering kettle, a condenser and a stirring kettle, and the stirring kettle is a full backmixing flow reactor; materials of the upper-stage standard kettle type module are transferred to the lower-stage standard kettle type module to form a continuously flowing plug flow on the flow model; an intermittent reaction is adopted in each standard kettle type module; the completion of one intermittent reaction is combined with the material transfer of one plug flow to form a pulse period. The invention has the following beneficial effects: firstly, intermittent pulse operation is adopted in a multi-kettle series reactor, that is, a flow model is continuous series full backmixing, a reaction process is periodic intermittent operation, and a pulse mode combining intermittent operation and continuous flow is adopted, so that materials are fully reacted in each kettle and then pulse to the next stage;

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of chemical reaction devices, and particularly relates to a high-efficiency continuous flow cauldron type module reaction device. BACKGROUND

[0002] Industrial reactors are divided into batch operation and continuous operation according to the flow mode of fluid. The continuous operation reactor is further divided into two types, continuous stirred tank operation and continuous flow tubular reactor. In order to utilize the advantages of full-mixed flow reactor, such as uniform mixing and easy temperature control, and to make the reaction not all under the condition of the lowest reactant concentration, multiple continuous cauldron type reactors are often used in series in industry to become a full-mixed flow reactor with multiple cauldrons in series. There is no backflow between the reactors in series, and the degree of backflow of the whole reactor is reduced by increasing the number of reactors in series. However, in actual situations, there will be dead angle conditions in the reaction space, and backflow cannot be completely avoided. In addition, although the full-mixed flow reactor with multiple cauldrons in series integrates the advantages of the previous two types, it has the disadvantages and difficulties of flow model in operation and control, such as complex control, inability to interrupt in the middle, and once a cauldron fails, the whole line will be paralyzed. SUMMARY

[0003] The present application aims at overcoming the deficiencies of the prior art, and provides a high-efficiency continuous flow cauldron type module reaction device.

[0004] To solve the above technical problems, the present application provides the following technical scheme: a high-efficiency continuous flow cauldron type module reaction device, comprising N multiple-stage serial standard cauldron type modules; the standard cauldron type module comprises a metering cauldron, a condenser and a stirred cauldron, wherein the stirred cauldron is a full backflow reactor; the material of the upper standard cauldron type module is transferred to the lower standard cauldron type module to form a continuous flow plug flow on the flow model; intermittent reaction is adopted in each standard cauldron type module, in the intermittent reaction stage, the stirred cauldron is an independent reaction unit and operates for a reaction time t, and the material transfer channel of each standard cauldron type module is in a closed state; one intermittent reaction combined with the material transfer of one plug flow forms one pulse cycle, and the reaction device has multiple repeated pulse cycles.

[0005] Preferably, the pulse cycle comprises a pulse feeding stage, an intermittent reaction stage, a pulse material transfer stage and a cleaning stage.

[0006] Preferably, in the pulse material transfer stage, the transfer of the material is realized by opening and closing the connecting valves between the reaction cauldrons in a short time, and by using the pressure difference, the height difference or the external conveying power between the reaction cauldrons.

[0007] Preferably, a central controller is further included, which uniformly sets and coordinates the reaction time t of the standard tank module, and uniformly instructs the start and stop of the pulse material transfer stage.

[0008] Preferably, the process conditions maintained by the at least two standard tank modules in series in the intermittent reaction stage are the same or different.

[0009] Preferably, the process conditions include one or more of temperature, pressure, stirring speed, and gas phase composition.

[0010] Preferably, the reaction material includes gas phase, liquid phase, and solid phase components, forming a gas-liquid-solid three-phase reaction system, wherein the solid phase component includes one of solid reactants, solid products, catalyst particles, or crystallized products.

[0011] Preferably, N is an integer greater than or equal to 4, and the standard tank module at the first stage is a feeding tank, and the standard tank module at the last stage is a buffer tank.

[0012] Preferably, the standard tank module further includes a material feeding pipe, a cleaning liquid feeding pipe, a module steel frame, a material discharging pipe, and a cleaning liquid discharging pipe.

[0013] The beneficial effects of the present application are: 1. The intermittent pulse operation is adopted in the multi-tank series reactor, i.e., the flow model is continuous series full back mixing, and the reaction process is periodic intermittent operation, which combines the pulse with "intermittent operation" and "continuous flow", so that the material is fully reacted in each tank and then pulsed to the next stage; 2. In one pulse flow cycle, the reaction device dynamically changes from multiple intermittent full back mixing reactors to an equivalent plug flow reactor, which has the uniform mixing property of full back mixing reactors and the driving force and high conversion rate of plug flow reactors; 3. It is easier to operate and control than the series tank continuous flow reactor, especially suitable for gas-liquid-solid three-phase reaction systems, and has the advantages of continuous characteristics, strong anti-blocking ability, and flexible operation. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 FIG. 1 is a structural schematic diagram of a standard tank module in the high-efficiency continuous flow tank module reaction device according to the present application;

[0015] Figure 2 FIG. 2 is a schematic diagram of an N-stage series structure of the high-efficiency continuous flow tank module reaction device according to the present application;

[0016] Figure 3 FIG. 3 is a structural schematic diagram of a single-tank full back mixing continuous reactor design model according to the present application;

[0017] Figure 4This is a schematic diagram of the design model of the plug flow continuous reactor described in this invention;

[0018] Figure 5 This is a schematic diagram of the design model of the multi-tank continuous flow reactor described in this invention;

[0019] Figure 6 This is a schematic diagram of the design model of the high-efficiency continuous flow reactor described in this invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. The described embodiments are some, but not all, of the embodiments of the present invention.

[0021] Example 1

[0022] Industrial reactors are classified into batch and continuous operation based on the fluid flow pattern. Continuous operation reactors are further divided into two types: continuous stirred tank reactors and continuous flow tubular reactors.

[0023] A batch reactor refers to a reactor in which the reactants are added all at once, thoroughly mixed, and then discharged after the reaction is complete. All materials enter the reactor simultaneously, making homogenization easy and preventing backmixing, resulting in minimal scale-up effects. However, batch operation requires heating and cooling processes, which significantly impacts reactor efficiency.

[0024] A continuous flow reactor is a type of fully backmixed reactor where materials continuously and steadily enter and exit, and the material concentration is the same in all compartments of the reactor. Because fresh material continuously enters the reactor, the reactant concentration remains at a low level, making it very difficult to achieve high conversion rates. To achieve the same final conversion rate as plug flow reactors, larger reactor volumes or longer residence times are required.

[0025] A tubular reactor is a type of plug flow reactor where the material flows forward like a piston, with no backmixing in the flow direction. The reactant concentration smoothly decreases from its highest value at the inlet to its lowest value at the outlet. Plug flow reactors require the smallest volume, are more compact, and have no dead zones in the reaction space, thus achieving higher conversion rates for the same volume compared to total backmixed reactors. However, they are prone to clogging in systems with high solids content or high viscosity and are not suitable for reactions with long reaction times.

[0026] The embodiment relates to a chemical reaction device which can be applied to liquid-liquid, liquid-solid, gas-liquid, gas-liquid-solid and other multiphase material systems. The device is innovative and is coupled with continuous flow and intermittent operation of multiple reactors in series, integrates intermittent operation, continuous flow and pulse feeding / discharging modes. The device is in the form of multiple reactors in series, is intermittent in a reaction kettle, has no back mixing, has partial back mixing in the multiple reactors in series, has a dead angle in a reaction space, and is independently operated in intermittent operation. If a middle kettle is damaged, the kettle can be skipped during transfer.

[0027] The intermittent operation is intermittent in a reaction kettle, but does not reach a terminal point, and is transferred to a next kettle for reaction when a conversion rate is 60%. The next kettle is also intermittent, and is transferred to a next kettle for intermittent reaction after reaction.

[0028] In a reaction period, material is stepwise and jumping in space, is continuously and fully reacted in each kettle in time, dynamically simulates model changes from full back mixing to plug flow, and operation switching from intermittent operation to continuous operation, so that respective advantages are ingeniously compatible, and limitations of a traditional method in processing multiphase systems are successfully overcome.

[0029] With reference to Figure 1 a schematic, the embodiment is a high-efficiency continuous flow kettle type module reaction device, which comprises N multiple-stage serial standard kettle type modules 1, the standard kettle type module 1 comprises a metering kettle 11, a condenser 12 and a stirring kettle 13, and the stirring kettle 13 is a full back mixing flow reactor.

[0030] Specifically, material of a higher standard kettle type module 1 is transferred to a lower standard kettle type module 1, and constitutes plug flow of continuous flow in a flow model; intermittent reaction is adopted in each standard kettle type module 1, the stirring kettle 13 is an independent reaction unit and operates for a reaction time t in the intermittent reaction stage, and a material transfer channel of each standard kettle type module 1 is in a closed state; one intermittent reaction combined with material transfer of plug flow is one pulse cycle, and the reaction device has multiple repeated pulse cycles.

[0031] In one mode of the embodiment, a pulse cycle comprises a pulse feeding stage, an intermittent reaction stage, a pulse material transfer stage and a cleaning stage.

[0032] In the pulse transfer stage, the transfer of the material is achieved by opening and closing the connecting valves between the reaction kettles in a short time, and by using the pressure difference, height difference or external conveying power between the reaction kettles. The reaction device further comprises a central controller which uniformly sets and coordinates the reaction time t of the standard kettle module 1, and uniformly instructs the opening and closing of the pulse transfer stage.

[0033] In one mode of the embodiment, the at least two standard kettle modules 1 connected in series maintain the same or different process conditions in the intermittent reaction stage. The process conditions include one or more of temperature, pressure, stirring speed, and gas phase composition.

[0034] In one mode of the embodiment, the reaction material contains gas phase, liquid phase and solid phase components, forming a gas-liquid-solid three-phase reaction system, wherein the solid phase component includes one of solid reactants, solid products, catalyst particles or crystalline products.

[0035] Referring to Figure 2 the schematic, in the embodiment, N is an integer greater than or equal to 4, the standard kettle module 1 at the first stage is a feeding kettle, the standard kettle module 1 at the last stage is a buffer kettle, and the intermediate ones are reaction kettles. It can also be understood that the standard kettle modules 1 from top to bottom are a feeding module, reaction modules 1-3 and a last buffer module. The number of reaction modules can be adjusted according to process requirements.

[0036] In one mode of the embodiment, the standard kettle module 1 further comprises a material feeding pipe 14, a cleaning liquid feeding pipe 15, a module steel frame 16, a material discharging pipe 17 and a cleaning liquid discharging pipe 18.

[0037] It should be noted that the purpose of the present application is to provide an innovative multi-kettle reaction device. The core is to couple the continuous flow and intermittent operation of the multi-kettle series, integrate the operation modes of "intermittent operation", "continuous flow" and "pulse feeding / discharging", and belong to the improvement of structure and structure linkage, rather than the principle of operation itself, such as how the reaction kettle reacts, how the controller controls, how the material and cleaning liquid are fed and discharged, how the valve is closed, how the feeding module feeds, and the principle of the buffer module, etc. Of course, the above is only an example of the technical problem, and of course it should also include but is not limited to the same or similar technical problems as above, which are not the essence of the present application, can be realized by referring to the prior art, and also belong to the non-essential technical features of the present application. Therefore, it should not be divorced from the core essence when judging whether the present application is fully disclosed, and therefore it is not described in detail.

[0038] The high-efficiency continuous-flow kettle module reaction device proposed in the embodiment has the following advantages:

[0039] One is to use intermittent pulse operation in a multi-kettle series reactor, the flow model is continuous series full back mixing, and the operation mode is periodic intermittent operation. In a pulse flow cycle, the device dynamically changes from multiple intermittent full back mixing reactors to an equivalent plug flow reactor. This dynamic compatibility of intermittent operation, continuous full back mixing and continuous plug flow is beneficial to mass transfer, heat transfer control of multiphase reaction, and in macroscopically realizes the high conversion rate close to plug flow, avoids the problem that the reactant concentration is diluted and the conversion rate is limited due to the back mixing of single continuous stirred tank. When the number of series devices is sufficient, it can be regarded as a plug flow process, which can completely offset the influence of back mixing and has no amplification effect.

[0040] The existing series multi-kettle is similar to the present application in device structure, which is a series of kettle devices. But the operation mode is different, the traditional one is continuous flow operation, continuous in and continuous out, continuous reaction, and the space of all kettles is connected. While the present application is independent intermittent reaction in each kettle, and the channel between kettles is closed.

[0041] Two is to allow "tailor-made" reaction conditions for each reaction stage, which can set different temperatures or pressures for each kettle in series, especially suitable for processes with optimal reactant concentration over time. In the traditional continuous flow reactor, all parameters in the same space are constant, and stability is its unique advantage. But in the present application, the reactions between kettles are independent and have no correlation, for example, the first kettle realizes rapid initial reaction at high temperature, the second kettle is beneficial to the balance moving to the product direction at low temperature, or inhibiting side reactions. This optimization is achieved in the intermittent stage of each kettle, which is difficult to achieve in the traditional continuous series kettle reactor (continuous operation of multi-kettle series is only a kind of continuous flow reactor, which must have material transfer at all times, and cannot be controlled individually). That is, the existing series multi-kettle device has material transfer between kettles at all times; while in the present application, the kettles are independent and can be optimized individually without affecting other kettles.

[0042] Three is flexible operation and easy integration, control is more convenient, and complex flow rebalancing is not required like continuous system, which is essentially a combination of a series of intermittent operations, and is very easy to integrate with automatic control system to realize intelligent production.

[0043] Four is the integration of standard modules, that is, each reactor uses a standard module device instead of a separate device, which can reduce operating costs and equipment costs.

[0044] Example 2

[0045] Reference Figure 3 The schematic is a single-kettle full back mixing continuous reactor design model.

[0046] In the flow of a CSTR in steady state operation, it is assumed that the material is mixed completely with the material in the reactor at the moment of entering the reactor and has the same concentration in the whole reactor space. Assuming that the volume of the reactor is V, the flow rate of the material is v0, the molar mass of A in the reactor is n A , the initial molar concentration is C A0 , the outlet molar concentration is C A , the molar reaction rate is r A , the reaction conversion rate is x A , the residence time is τ, the molar amount entering the reactor per unit time is F A0 , the molar amount leaving the reactor per unit time is F Af , the molar concentration before the reaction is C A0 , and the molar concentration after the reaction is C A , the volume design equation of the CSTR is:

[0047]

[0048] If the flow rate v0 of the material is constant and τ = V / v0, the design equation can also be:

[0049]

[0050] It can be seen that the model equation is an algebraic equation.

[0051] Referring to the schematic of Figure 4 , for the design model of a plug flow continuous reactor:

[0052] Assuming that the length of the pipeline is L, the unit microelement length is dy, the cross-sectional area is Ac, and the volume is V. Then it can be arranged as:

[0053]

[0054] Let τ represent the residence time of the microelement in the reactor, and obviously τ = V / v0, A and f are the time nodes entering and leaving the reactor per unit time, respectively, and the design equation is:

[0055]

[0056]

[0057]

[0058] It can be seen that the model equation is a differential equation.

[0059] Further, referring to the schematic of Figure 5 , the schematic is a design model of a multi-kettle series continuous flow reactor.

[0060] The reactants flow into the next reactor from the previous reactor in the series of reactors. Let V R1 R2 Rn be the effective volume of each reactor (m 3 ), C A1 , C A2 , …, C An be the concentration of the reactant A in the reactor (mol / m 3 ), and V0 be the volumetric flow rate of the reactant (m 3 / s). Under the condition of the same flow rate and volume of each reactor, any reactor i in the series of reactors is a single reactor. It is not difficult to understand that F Ai is the number of moles of the reactant entering the reactor per unit time in reactor i, F A0 is the number of moles of the reactant entering the reactor per unit time in the first reactor when i is 0, x Ai is the conversion rate of reactor i, and the meanings of other letters can be understood in the same way.

[0061] The outlet conversion rate x i of each reactor in the series is defined, and the design equation is:

[0062]

[0063]

[0064]

[0065] The total volume can be obtained from the above equation:

[0066]

[0067] When n→∞,

[0068]

[0069] The above equation is the same as the plug flow reaction flow model, that is, when n tends to infinity, the model is considered as a plug flow model. Obviously, when the reaction order n is changed, the flow model can be changed between the complete mixing flow and the plug flow.

[0070] Referring to the schematic of Figure 6 , a design model of a high-efficiency continuous flow reactor module is proposed in this embodiment. In this embodiment, the operation of the high-efficiency continuous flow reactor is intermittent, that is, there is no addition of material and no product flow during the reaction process. Therefore, the accumulation rate and the consumption rate in the reactor have the following relationship:

[0071]

[0072] For a constant-volume process,​​ , , then:

[0073]

[0074] For a system consisting of N reactors, each reactor takes t / N time and each reactor releases V / N volume. When N→∞, the flow can be regarded as a plug flow model.

[0075] Further, the high-efficiency continuous-flow tank module reaction device comprises a reaction method as follows:

[0076] The reaction device is provided with N-stage module devices, that is, n reaction tanks, numbered R1-Rn from top to bottom;

[0077] The material to be reacted is put into the reaction tank R1;

[0078] Intermittent reaction is carried out in the reaction tank R1;

[0079] The material in the reaction tank R1 is completely transferred to the next-stage reaction tank R2;

[0080] The solvent is introduced into the reaction tank R1 for cleaning, and after cleaning, R1 enters the empty tank (waiting for material) state;

[0081] The above step is defined as a cycle time t, and the material is transferred step by step and the cycle is repeated;

[0082] The material in the reaction tank Rn is completely transferred to the next-stage reaction tank R(n+1);

[0083] The solvent is introduced into the reaction tank Rn for cleaning, and after cleaning, Rn enters the empty tank (waiting for material) state

[0084] The material in the reaction tank R(n-1) is completely transferred to the next-stage reaction tank Rn;

[0085] The solvent is introduced into the reaction tank R(n-1) for cleaning, and R(n-1) enters the empty tank (waiting for material) state;

[0086] The entire product in the last-stage reaction tank is transferred to the buffer tank as output material;

[0087] New material is put into the first-stage reaction tank R1;

[0088] After the pulse transfer stage is completed, the system is reset to the pulse feeding stage, and the next operation is started.

[0089] Example 3

[0090] To verify the actual effect of the high-efficiency continuous-flow tank module reaction device, this embodiment compares the actual synthesis experiment of a product.

[0091] Experimental method:

[0092] The high-efficiency continuous flow reaction device of the present application is the experimental device, and the continuous kettle type reaction device, the continuous pipe type reaction device, and the multi-kettle series kettle type reaction device are the control devices.

[0093] The total reaction volume is 1000L:

[0094] The main reaction equipment of the continuous kettle type reaction device is one 1000L reaction kettle

[0095] The main reaction equipment of the continuous pipe type reaction device is one 200-meter-long 0.08-meter-diameter pipeline.

[0096] The full-mixed flow reactor of the multi-kettle series is five 200L reaction kettles in series.

[0097] The main reaction equipment of the high-efficiency continuous flow reaction device of the present application is five 200L reaction kettles.

[0098] (1) Product yield comparison:

[0099] The total residence time is controlled to be 60min (or the stirring time in the kettle), the product yield is detected by sampling, each group of experiments is repeated for three times, and the average value is taken, and the results are as follows in Table 1.

[0100] Table 1: Product yield comparison group.

[0101] Serial number Operation mode Volume First time Second time Third time Yield average 1 Continuous stirred tank reactor 1000L 80.20% 79.80% 80.40% 80% 2 Continuous tubular reactor 1000L 97.70% 98.80% 98.60% 98% 3 Multi-tank series reactor 5×200L 95.20% 94.50% 95.30% 95% 4 High-efficiency continuous flow reactor 5×200L 99.20% 99.50% 99.30% 99%

[0102] (2) Residence time comparison:

[0103] The product yield is detected by sampling every 5min, the experiment is stopped after 95%, each group of experiments is repeated for three times, and the average value is taken, and the results are as follows in Table 2.

[0104] Table 2: Residence time comparison group.

[0105] Serial number Operation mode Volume First time Second time Third time Residence time average 1 Continuous stirred tank reactor 1000L 80 min 90 min 85 min 85.0 min 2 Continuous tubular reactor 1000L 50 min 45 min 50 min 48.3 min 3 Multi-tank series reactor 5×200L 55 min 55 min 50 min 53.3 min 4 High-efficiency continuous flow reactor 5×200L 50 min 45 min 45 min 46.7 min

[0106] From the above experiments, the average value of the residence time is the reaction time, and the transfer time of the material is not included. The high-efficiency continuous flow kettle type module reaction device of the present application is obviously higher than the traditional mode in yield and shorter in residence time. Table 1 experiment shows that the product yield is the highest by using the device of the present application; and Table 2 experiment shows that the time used is the least by using the device of the present application.

[0107] It should be noted that the above examples are only used to illustrate the technical solutions of the present application but not to limit the protection scope of the present application. Those skilled in the art can make other different forms of changes or modifications on the basis of the above description and ideas, which are not required or can not be listed here. Any modification, equivalent replacement and improvement made within the spirit and principle of the technical solutions of the present application should be covered within the protection scope of the claims of the present application.

Claims

1. A high efficiency continuous flow tank module reactor apparatus, characterized by: Comprising, N standard tank modules (1) connected in series; The standard tank module (1) comprises a metering tank (11), a condenser (12), and a stirred tank (13); The material of the upper standard tank module (1) is transferred to the lower standard tank module (1) to form a continuous flow of plug flow on the flow model; Each standard tank module (1) uses batch reaction, and in the batch reaction stage, the stirred tank (13) is an independent reaction unit and operates for a reaction time t, and the material transfer channel of each standard tank module (1) is in a closed state; One batch reaction combined with one material transfer of plug flow is one pulse cycle, and the reaction device has a plurality of repeated pulse cycles.

2. The high efficiency continuous flow batch module reaction apparatus according to claim 1, characterized by: The pulse cycle includes a pulse feeding stage, a batch reaction stage, a pulse material transfer stage, and a cleaning stage.

3. The high efficiency continuous flow batch module reaction apparatus according to claim 2, characterized by: In the pulse material transfer stage, the material transfer is realized by opening and closing the connection valve between the reaction tanks in a short time, and by using the pressure difference, the height difference, or the external conveying power between the reaction tanks.

4. The high efficiency continuous flow batch module reaction apparatus according to claim 2, characterized by: Further comprising a central controller, which uniformly sets and coordinates the reaction time t of the standard tank module (1), and uniformly instructs to open and close the pulse material transfer stage.

5. The high efficiency continuous flow batch module reaction apparatus according to claim 2, characterized by: The at least two standard tank modules (1) connected in series maintain the same or different process conditions in the batch reaction stage.

6. The high efficiency continuous flow batch module reaction apparatus according to claim 5, characterized by: The process conditions include one or more of temperature, pressure, stirring speed, and gas phase composition.

7. The high efficiency continuous flow batch module reaction apparatus according to claim 1, characterized by: The reaction material contains gas phase, liquid phase, and solid phase components to form a gas-liquid-solid three-phase reaction system, wherein the solid phase component includes one of solid reactants, solid products, catalyst particles, or crystalline products.

8. The high efficiency continuous flow batch module reaction apparatus according to claim 1, characterized by: The N is an integer greater than or equal to 4, and the standard tank module (1) at the first stage is a feeding tank, and the standard tank module (1) at the last stage is a buffer tank.

9. The high efficiency continuous flow batch module reaction apparatus according to claim 1, wherein: The standard tank module (1) further comprises a material feeding pipeline (14), a cleaning liquid feeding pipeline (15), a module steel frame (16), a material discharging pipeline (17), and a cleaning liquid discharging pipeline (18).

Images