Process and integrated reaction device for the continuous preparation of acrylamide

Abstract

The present application relates to the technical field of acrylamide preparation, and discloses a process and an integrated reaction device for preparing acrylamide by a continuous method. The preparation process is carried out in the integrated reaction device. Acrylonitrile, pure water and biological enzyme are injected from the top of the tower, flow downward along the filler and generate acrylamide. Along the material flow direction, acrylamide with a concentration of 20-30% and 30-40% is extracted in turn, the biological enzyme is injected into the reaction tower through the enzyme separation membrane group, and reacts with the remaining material to generate acrylamide. Acrylonitrile is supplemented and the remaining material is diverted from the bottom to the other half of the tower to continue to react to generate acrylamide. The final concentration of acrylamide is extracted, and the biological enzyme is recycled through the enzyme separation membrane group. The present application has the advantages that the preparation process is highly concentrated in the integrated reaction device, the reaction period is short, the land occupation is small, the energy efficiency ratio is high, the biological enzyme recycling rate is high, acrylamide solutions with different concentrations can be extracted simultaneously in the same equipment, and the present application is suitable for industrial production.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of acrylamide preparation, and particularly relates to a process for preparing acrylamide by a continuous method and an integrated reaction device. BACKGROUND

[0002] Acrylamide is a white crystalline chemical substance, is a raw material for producing polyacrylamide, and is widely used in sewage treatment in environmental protection, oil three mining, coating, fine chemical industry and papermaking industry. The traditional process for preparing acrylamide is the first generation: concentrated sulfuric acid catalysis; the second generation: skeleton copper catalysis; and the third generation: microbial catalysis. The microbial catalysis method is mainly based on nitrile hydratase, and acrylonitrile (AN) and water are added to a reaction container, and a hydration reaction occurs under the catalysis of the enzyme of the microorganism, and then the crude acrylamide solution obtained is filtered by a membrane to separate and purify, so that the acrylamide solution with impurities removed is obtained.

[0003] At present, the biological method for preparing acrylamide mainly includes a batch method and a continuous method. The process of producing acrylamide by the batch method is intermittent, and each batch of fermentation liquid needs to be repeatedly performed from inoculation, culture, growth, maturation and tank release, so that the operation is complex, the production cycle is long, and the product quality is difficult to control. Moreover, with the gradual increase of the product concentration in the reaction solution and the extension of the reaction period, there are problems of low product yield and single concentration.

[0004] Although the continuous method for producing acrylamide can continuously produce acrylamide, at present, most of the continuous production processes are multi-kettle series or single-kettle continuous production processes. The multi-kettle series production process is to realize the continuous production of acrylamide by connecting multiple reaction kettles in series, but the reaction period of the multi-kettle series is long, the occupied area is large, and 40-70% of new biological enzymes need to be supplemented in each production cycle, so the investment is high. The method and device for preparing acrylamide by a continuous microbial method disclosed in CN105420302A are reacted in the same reaction kettle, and the single-kettle continuous production process is adopted. Although the problem of large occupied area of the multi-kettle series is solved, since the specific gravity of AN is 80% of that of water and AN is insoluble in water, the rate of material mixing is slow, the material needs to be forcibly stirred, the yield is low, the energy consumption is high, and the same equipment can only produce acrylamide solution with one concentration at the same time, so it is difficult to meet the current production demand. SUMMARY

[0005] The technical problem to be solved by the present application is to provide a process for preparing acrylamide by a continuous method. The preparation process is highly concentrated in the integrated reaction device, the reaction period is short, the occupied area is small, the energy efficiency ratio is high, the biological enzyme reuse rate is high, the same equipment can simultaneously produce acrylamide solutions with different concentrations, and the process is suitable for industrial production.

[0006] The present application solves the above technical problems by the following technical means:

[0007] The application provides a continuous process for preparing acrylamide, which is carried out in an integrated reaction device, wherein the integrated reaction device comprises a reaction tower and a vertical partition plate fixed in the reaction tower, the vertical partition plate separates the reaction tower into two half-towers, and an unsealed space between the vertical partition plate and the bottom of the reaction tower allows the two half-towers to communicate with each other.

[0008] The process for preparing acrylamide comprises the following steps:

[0009] (1) acrylonitrile, pure water and biological enzyme are injected from the top of the half-tower on one side of the reaction tower, and the feeding pressure allows the mixture to flow downwards along the filler in the half-tower, and meanwhile, acrylamide is generated by reaction under stable temperature conditions;

[0010] (2) when the concentration of acrylamide reaches 20%-30%, part of the mixture is collected from the first collection outlet of the reaction tower, and the first concentration product and biological enzyme are separated by the enzyme separation membrane group, and the remaining mixture in the reaction tower continues to flow downwards and continuously reacts to generate acrylamide under stable temperature conditions;

[0011] (3) when the concentration of acrylamide generated by the reaction of the remaining mixture reaches 30%-40%, part of the mixture is collected from the second collection outlet of the reaction tower, and the second concentration product and biological enzyme are separated by the enzyme separation membrane group; the biological enzyme separated in the step (2) and the step (3) is injected into the reaction tower and mixed with the remaining mixture at the corresponding injection position;

[0012] (4) when the biological enzyme and the remaining mixture flow to the bottom of the reaction tower, and acrylonitrile is supplemented from the bottom of the reaction tower at the same time, the mixture is diverted into the half-tower on the other side of the reaction tower and flows upwards along the filler, and meanwhile, acrylamide is continuously generated by reaction under stable temperature conditions;

[0013] (5) when the mixture flows to the third collection outlet at the top of the half-tower on the other side of the reaction tower, the mixture is collected from the third collection outlet and separated by the enzyme separation membrane group to obtain the third concentration product and biological enzyme, and the biological enzyme is reused for the initial reaction.

[0014] The application uses the reaction tower provided with a vertical partition plate as a reaction main container, the raw materials flow along the filler and mix after entering the reaction tower, and meanwhile, acrylamide is generated by reaction; with the continuous flow and mixing of the mixture, the concentration of acrylamide gradually increases along the flow direction, and at this time, acrylamide with different concentrations can be obtained from different collection outlets of the reaction tower, different concentrations of acrylamide solution can be collected from the same equipment at the same time, and customers can conveniently extract acrylamide with different contents in a segmented manner according to requirements.

[0015] In this application, acrylamide with a concentration of less than 40% is synthesized in one half of the reaction tower; acrylamide with a concentration of more than 40% is synthesized in the other half of the reaction tower. This occupies half of the process space of the reaction tower, providing sufficient reaction time. At the same time, the bio-enzymes separated and reused by the enzyme separation membrane and the new acrylonitrile added to the bottom of the reaction tower effectively promote the generation of acrylamide, further improving the rate and yield of acrylamide generation.

[0016] The preparation process of this application is highly concentrated in an integrated reaction device, combining the advantages of both batch and continuous methods. On the one hand, it transforms the horizontally occupying multi-stage reaction equipment into a vertically occupying tower reactor, resulting in a shorter reaction cycle, less equipment footprint, and reduced fixed asset investment. Simultaneously, the feed pressure at the top of the reaction tower propels the material to flow within the tower, naturally forming a homogeneous state as it flows through the packing material, eliminating the need for additional power to stir the material and reducing equipment operating energy consumption. On the other hand, after separation, the bio-enzymes from different concentrations collected in different steps of this application are immediately recycled back into the reaction tower to participate in subsequent reactions. This not only achieves unlimited recycling of bio-enzymes but also effectively utilizes the robust effective lifespan of the bio-enzymes. Therefore, only a small amount of new bio-enzymes needs to be added during each production cycle to maintain an ideal yield, significantly reducing the amount of bio-enzymes used. Furthermore, the bio-enzymes in this application are separated and recycled simultaneously, reducing intermediate bio-enzyme storage and the energy required for re-transportation from storage tanks to the reactor, resulting in advantages such as low investment, low energy consumption, and high energy efficiency.

[0017] Preferably, in step (1), the mass ratio of acrylonitrile, pure water, and biological enzyme is 350:1200:0.4-1.

[0018] Beneficial effects: In actual production, users can design and adjust the proportion of each raw material according to actual needs to obtain the required concentration of acrylic acid.

[0019] Preferably, the feed pressure at the top of the reaction tower in step (1) and the feed pressure for adding acrylonitrile in step (4) are both 0.25 to 0.35 MPa.

[0020] Beneficial effects: This application utilizes the feed pressure at the top of the reaction tower to convert it into a driving force and a hybrid power for the material to flow along the reaction tower; when the material flows upward along the other half of the tower, the feed pressure of the added acrylonitrile further enhances the driving force and hybrid power of the material flow, ensuring the smooth flow of the material in the reaction tower.

[0021] Preferably, in step (2), acrylonitrile is added after a portion of the material is extracted from the first extraction outlet, and the amount of acrylonitrile added in both steps (2) and (4) is 10% to 15% of the amount of acrylonitrile used in step (1).

[0022] Preferably, in steps (2) and (3), the pore size of the filter membrane of the enzyme separation membrane group is 0.05-0.15 μm, and the recycling rate of the biological enzyme is ≥99%; in step (5), the pore size of the filter membrane of the enzyme separation membrane group is 0.15-0.35 μm, and the recycling rate of the biological enzyme is 85%-95%.

[0023] Beneficial effects: This application allows the bioenzyme to be separated and reused in the system for the next reaction. It has a long effective life cycle and low mechanical loss, realizing the unlimited recycling of bioenzymes. Only 5% to 16% of new bioenzymes need to be added in each production cycle to maintain the ideal yield, which is far lower than the 40% to 70% additional addition required by batch and continuous methods. This greatly reduces the amount of bioenzyme used and further reduces the preparation cost.

[0024] Preferably, the bioenzymes obtained in steps (2) and (3) are injected into the reaction tower by injecting them separately or together.

[0025] Preferably, the reaction tower is provided with multiple layers of heat exchange tube bundles along the material flow direction, and one layer is added for every 2 to 3°C increase, so that the temperature inside the reaction tower is stabilized at 18 to 20°C.

[0026] Beneficial effects: By setting up a multi-layer heat exchange tube bundle, this application removes the heat generated during the acrylamide production process, achieving precise temperature control and stabilizing the temperature of the reaction tower at 18-20℃, which helps to ensure the reaction rate and yield.

[0027] In another aspect, the present invention proposes an integrated reaction apparatus for the above-mentioned continuous process for preparing acrylamide. The integrated reaction apparatus includes a reaction tower, a vertical partition, a heat exchange tube bundle, and packing. The vertical partition is fixed inside the reaction tower and divides the reaction tower into two half-towers. The unsealed space between the vertical partition and the bottom of the reaction tower connects the two half-towers. One half-tower has a feed inlet at its top and the other half-tower has a discharge outlet at its top. The bottom of the reaction tower also has a feed outlet.

[0028] The half-tower is fixedly equipped with multiple layers of heat exchange tube bundles along its length, and the packing is supported on the heat exchange tube bundles and filled between adjacent heat exchange tube bundles.

[0029] At least two sampling outlets are provided at different height positions of the reaction tower body. Each sampling outlet is equipped with an enzyme separation membrane group for separating biological enzymes in the sampled material. The separated biological enzymes are injected into the reaction tower through a reflux pipe.

[0030] Beneficial Effects: In use, the integrated reaction apparatus of this application injects raw materials such as acrylonitrile, pure water, and bio-enzymes into the reaction tower through the feed inlet. The materials flow and mix within the packing material of the half-tower on the feed side, simultaneously reacting to generate acrylamide. The concentration of acrylamide gradually increases along the material flow direction. Users can collect the required concentration of acrylamide at the corresponding outlet according to production needs, achieving simultaneous collection of acrylamide solutions of different concentrations from the same equipment. During the synthesis process, the temperature of the reaction tower is maintained within a fixed range by controlling the heat exchange tube bundle, preventing the heat generated during the reaction from causing a temperature rise that is detrimental to the forward reaction. Furthermore, the bio-enzymes separated by the enzyme separation membrane are recycled back into the reaction tower. This reduces the amount of new bio-enzymes required, lowering costs. On the other hand, when the reaction in the tower approaches equilibrium, new acrylonitrile and the recycled bio-enzymes are added through the feed inlet, increasing the concentration of raw materials, promoting the forward reaction, and further improving the yield.

[0031] Preferably, the bottom end of the vertical baffle extends to half the height of the tower bottom head; the distance between the highest layer of packing and the top of the tower and the distance between the lowest layer of packing and the bottom of the tower are both 0.2 to 0.6 m.

[0032] Beneficial effects: The bottom of the vertical baffle in this application extends to half the height of the tower bottom head, and there is space between the lowest layer of packing and the tower bottom, providing sufficient space for the material to move from one half of the tower to the other side; there is space between the highest layer of packing and the tower top, which is conducive to material collection and will not block the material hole.

[0033] Preferably, the packing material in the reaction tower is PP multifaceted hollow spheres, and the porosity of the spherical PP packing material is 90% to 95%.

[0034] Beneficial effects: The reaction tower of this application uses PP multifaceted hollow spheres with a porosity of 90% to 95%, in which multiple plate-like spherical petals are arranged radially along the central axis, so that the packing has a large porosity, which is conducive to maintaining a uniform mixing state during the material flow process.

[0035] Preferably, the heat exchange tube bundle is cooled by the inflow and outflow of cooling water, and a pneumatic regulating valve for controlling the flow rate of the cooling water is installed on the heat exchange tube bundle; a thermometer for monitoring the temperature of the heat exchange tube bundle is installed in the reaction tower, and the pneumatic regulating valve is adjusted by the feedback data from the thermometer to control the temperature of the reaction tower.

[0036] Beneficial effects: This application uses thermometer feedback data to adjust the pneumatic regulating valve to control the cooling water flow so that the temperature difference between adjacent heat exchange tube bundles is 2-3℃, achieving multi-point precise temperature control and keeping the reaction tower temperature within a stable range, which is beneficial for the forward synthesis of acrylamide, thereby improving the acrylamide formation rate and yield.

[0037] Preferably, a collection tank for storing the collected material and a pressurizing pump for pressing the material in the collection tank into the enzyme separation membrane group are provided between the reaction tower and the enzyme separation membrane group. The pressure of the pressurizing pump enables the separation of acrylamide and biological enzyme in the material within the enzyme separation membrane group.

[0038] Beneficial effects: In this application, the material collected from the reaction tower enters the collection tank, and then is pressurized into the enzyme separation membrane group by a pressure pump, so that the material is separated while flowing in the enzyme separation membrane group. Acrylamide is filtered out through the filter membrane, and the concentration of biological enzyme cells inside the filter membrane gradually increases until it flows out of the enzyme separation membrane group and flows back into the reaction tower to continue to participate in the reaction.

[0039] The advantages of this invention are:

[0040] 1. This application uses a reaction tower equipped with vertical baffles as the main reaction vessel. After the raw materials enter the reaction tower, they flow and mix along the packing, and acrylamide is produced at the same time. As the materials continue to flow and mix, the concentration of acrylamide gradually increases along the flow direction. At this time, acrylamide of different concentrations can be obtained from different outlets of the reaction tower, realizing the simultaneous extraction of acrylamide solutions of different concentrations from the same equipment, which is convenient for customers to extract acrylamide of different contents in stages according to their needs.

[0041] 2. In this application, acrylamide with a concentration of less than 40% is synthesized in one half of the reaction tower; acrylamide with a concentration of more than 40% is synthesized in the other half of the reaction tower. This occupies half of the process space of the reaction tower, providing sufficient reaction time. At the same time, the bio-enzymes separated and reused by the enzyme separation membrane and the new acrylonitrile added to the bottom of the reaction tower effectively promote the generation of acrylamide, further improving the rate and yield of acrylamide generation.

[0042] 3. The preparation process of this application is highly concentrated in an integrated reaction device, combining the advantages of both batch and continuous methods. On the one hand, it transforms the horizontally occupying multi-stage reaction equipment into a vertically occupying tower reactor, resulting in a shorter reaction cycle and less equipment footprint, thus reducing fixed asset investment. Simultaneously, the feed pressure at the top of the reaction tower propels the material to flow within the tower, naturally forming a homogeneous state as it flows through the packing material, eliminating the need for additional power to stir the material and reducing equipment operating energy consumption. On the other hand, after separation, the bio-enzymes from different concentrations collected in different steps of this application are immediately recycled back into the reaction tower and participate in subsequent reactions. This not only achieves unlimited recycling of bio-enzymes but also effectively utilizes the robust effective lifespan of the bio-enzymes. Therefore, only a small amount of new bio-enzymes needs to be added during each production cycle to maintain an ideal yield, significantly reducing the amount of bio-enzymes used. Furthermore, the bio-enzymes in this application are separated and recycled simultaneously, reducing intermediate bio-enzyme storage and the energy required for re-transportation from storage tanks to the reactor, resulting in advantages such as low investment, low energy consumption, and high energy efficiency. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of the overall structure of the integrated reaction device in Embodiment 1 of this application.

[0044] Figure 2 This is a schematic diagram of the heat exchange tube bundle in Embodiment 1 of this application.

[0045] Figure 3 This is a schematic diagram of the enzyme separation membrane assembly in Example 1 of this application.

[0046] Explanation of reference numerals in the attached figures:

[0047] 1. Vertical partition; 2. Packing material; 3. Heat exchange tube bundle; 4. Enzyme separation membrane assembly; 5. Pressure pump. Detailed Implementation

[0048] 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 in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0049] Unless otherwise specified, all test materials and reagents used in the following examples are commercially available.

[0050] Unless otherwise specified in the embodiments, the techniques or conditions described in the literature in this field or in accordance with the product manual may be followed.

[0051] Example 1

[0052] This embodiment provides an integrated reaction apparatus for a continuous process of preparing acrylamide. For example... Figure 1 As shown, the integrated reaction apparatus includes a reaction tower, a vertical partition 1, a heat exchange tube bundle 3, packing material 2, a collection tank, an enzyme separation membrane assembly 4, and a pressure pump 5. The reaction tower is cylindrical with its length vertical. The vertical partition 1 is made of stainless steel, and its top and side walls are attached to and fixedly connected to the inner wall of the reaction tower, thereby dividing the reaction tower into a left half-tower and a right half-tower. The bottom end of the vertical partition 1 extends to half the height of the bottom head of the tower, and the unsealed space between the vertical partition 1 and the bottom of the reaction tower connects the left and right half-towers.

[0053] like Figure 2As shown, the heat exchange tube bundle 3 is formed into a semi-disc shape by spiraling heat exchange tubes, with gaps between adjacent spiral heat exchange tubes to allow material passage. The lines in the diagram represent a schematic of the piping; the left side shows three parallel water inlets, and the right side shows three parallel water outlets. The arrows indicate the flow direction of the cooling water. The heat exchange tube bundle 3 is horizontally fixed inside the reaction tower, and it has multiple layers along the length of half the tower. The distance between adjacent heat exchange tube bundles 3 is 0.5–2 m, gradually increasing from the shortest distance between the first layer to the last layer. The heat exchange tube bundle 3 has inlets and outlets. The inlets are connected to the cooling water; as the cooling water flows through the heat exchange tube bundle 3, it exchanges heat with the reaction tower and then exits through the outlet, achieving cooling inside the reaction tower. The packing 2 consists of spherical PP multifaceted hollow spheres with a diameter of 38 mm, which are supported on the heat exchange tube bundle 3 and fill the spaces between adjacent heat exchange tube bundles 3. After filling, the porosity of the packing 2 is 90–95%. Furthermore, the highest layer of packing material 2 is 0.5m from the top of the tower, and the lowest layer of packing material 2 is 0.5m from the bottom of the tower.

[0054] like Figure 1 As shown, the left half-tower has a feed inlet at the top, a first outlet at the bottom, and a second outlet at the bottom; the right half-tower has a third outlet at the top; and the reaction tower has a feed inlet at the bottom. In operation, acrylonitrile, pure water, and bio-enzymes are injected into the left half-tower through the feed inlet in a set mass ratio using a material pump. At this time, the materials are propelled downwards along the left half-tower by gravity and inlet pressure, and are mixed evenly under the agitation of packing 2, simultaneously reacting to generate acrylamide.

[0055] like Figure 1As shown, there are three collection tanks, placed outside the first, second, and third collection outlets respectively. Material from each outlet is transported to its corresponding collection tank via a discharge pipe. A discharge control valve is installed on the discharge pipe to control the discharge of material from the corresponding outlet. An online acrylamide concentration detector is also installed inside the reaction tower. During acrylamide synthesis, when the acrylamide concentration in the left half of the tower reaches 30%, the discharge control valve of the first outlet is controlled, opening the first outlet. At this time, a portion of the 30% acrylamide mixture is collected from the first outlet and enters its corresponding collection tank. Simultaneously, acrylonitrile is added below the first outlet to continue reacting with the remaining material in the reaction tower to generate acrylamide. Similarly, when the acrylamide concentration in the left half of the tower reaches 40%, a portion of the 40% acrylamide mixture is collected from the second outlet. The material flows into its corresponding collection tank, where it continues to react and generate acrylamide. When the remaining material reaches the bottom of the left half of the tower, it is redirected to the right half of the tower through the unsealed space between the vertical baffle 1 and the bottom of the reaction tower. At the same time, acrylonitrile is added through the feed inlet. The pressure of the added material provides the driving force, causing the newly added acrylonitrile to flow upward along the right half of the tower with the remaining material and continue to react and generate acrylamide. When the acrylamide concentration reaches 50%, all the material in the right half of the tower is extracted through the third outlet and enters its corresponding collection tank, thus achieving the simultaneous extraction of acrylamide of different concentrations from the same equipment.

[0056] like Figure 3 As shown, the enzyme separation membrane module 4 uses existing hollow fiber module equipment, including a membrane frame and a filter membrane. The membrane frame has a PP shell, and the filter membrane is a polyethersulfone membrane installed inside the membrane frame. A pressure pump 5 is installed between the enzyme separation membrane module 4 and the collection tank. The pressure pump 5 pumps the material stored in the collection tank into the enzyme separation membrane module 4. The material flows within the membrane frame and is separated by the filter membrane, thereby achieving the separation of acrylamide and the biological enzyme in the material. Figure 1 As shown, the enzyme separation membrane group 4 and the pressurizing pump 5 are each equipped with three sampling outlets. The first and second sampling outlets correspond to a pore size of 0.05 μm in the filter membrane of the enzyme separation membrane group 4, and the third sampling outlet corresponds to a pore size of 0.20 μm in the filter membrane of the enzyme separation membrane group 4.

[0057] like Figure 1As shown, when the material from the first outlet is pumped into the enzyme separation membrane group 4, a 30% acrylamide solution and bio-enzyme are separated. When the material from the second outlet is pumped into the enzyme separation membrane group 4, a 40% acrylamide solution and bio-enzyme are separated. These two enzyme separation membrane groups 4 are connected to the bottom of the reaction tower through the same reflux pipe, allowing the separated bio-enzyme to flow back into the reaction tower and react with the remaining material and newly added acrylonitrile to generate acrylamide. At this point, the bio-enzyme recovery rate is ≥99%. When the material from the third outlet is pumped into the enzyme separation membrane group 4, a 50% acrylamide solution and bio-enzyme are separated. This enzyme separation membrane group 4 is connected to the feed inlet through a reflux pipe, allowing the separated bio-enzyme to flow back into the reaction tower to participate in the initial reaction to generate acrylamide. By separating and recovering the bio-enzyme in the acrylamide mixture simultaneously, the amount of bio-enzyme used is effectively reduced.

[0058] like Figure 1 As shown, a thermometer, specifically a Pt100 bimetallic thermometer, is installed inside the reaction tower, positioned near the heat exchange tube bundle 3 to monitor its temperature. A pneumatic regulating valve is installed at the inlet of the heat exchange tube bundle 3. During operation, the heat released during acrylamide formation causes the reaction tower temperature to rise. The pneumatic regulating valve is adjusted based on the thermometer feedback data to control the cooling water flow, maintaining the temperature difference between adjacent heat exchange tube bundles 3 at 2–3°C. This, in turn, controls the overall temperature inside the reaction tower at 18–20°C, which is beneficial for acrylamide formation. Both the pneumatic regulating valve and the thermometer are connected to the DCS system via a 4–20mA signal. The thermometer transmits the measured temperature value to the DCS system, which automatically controls the pneumatic regulating valve to adjust the cooling water flow, thus achieving automatic temperature control of the reaction tower.

[0059] This embodiment also provides a continuous process for preparing acrylamide, which is carried out in the above-mentioned integrated reaction apparatus and includes the following steps:

[0060] (1) Acrylonitrile, pure water and biological enzymes are injected into the left half tower through the pressurization action of the material pump at a mass ratio of 350:1200:1. Gravity and 0.35 MPa feed pressure cause the mixture to flow down along the packing in the left half tower and mix evenly. At the same time, acrylamide is generated by reaction under the temperature conditions of 18-20℃.

[0061] (2) According to the data fed back by the online acrylamide concentration detector, when the concentration of acrylamide in the reaction tower reaches 30%, some material is taken out from the first outlet of the reaction tower according to production needs. After entering the collection tank, it is pumped to the enzyme separation membrane group by the pressurized pump. The first concentration product and biological enzyme are separated by the enzyme separation membrane group. The material taken out from the first outlet includes 20% solid biological enzyme cells and 80% acrylamide aqueous solution. The concentration of acrylamide remains unchanged before and after membrane separation, so the concentration of the first concentration product is still 30%. Acrylonitrile with an initial acrylonitrile dosage of 13% is added below the first outlet so that it continues to flow downward with the remaining material in the reaction tower and continues to react to generate acrylamide at a temperature of 18-20℃.

[0062] (3) According to the data fed back by the online acrylamide concentration detector, when the concentration of acrylamide in the reaction tower reaches 40%, some material is taken out from the second outlet of the reaction tower according to production needs. After entering the collection tank, it is pumped to the enzyme separation membrane group by the pressurized pump and separated by the enzyme separation membrane group to obtain the second concentration product and biological enzyme. The material taken out from the second outlet includes 27% solid biological enzyme cells and 73% acrylamide aqueous solution. The concentration of acrylamide remains unchanged before and after membrane separation, so the concentration of the second concentration product obtained is still 40%. The biological enzyme obtained in this step and in step (2) is injected into the bottom of the reaction tower and mixed with the remaining material. The recycling rate of biological enzyme in this process is ≥99%.

[0063] (4) When the above-mentioned biological enzyme and the remaining material mixture flow to the bottom of the reaction tower, the mixture turns into the right half of the tower. At the same time, 10% of the initial acrylonitrile dosage is added through the feed port. The material pump provides a pressure of 0.25 MPa as the driving force for the added material and the remaining material, so that the newly added acrylonitrile flows upward along the right half of the tower with the remaining material and continues to react to generate acrylamide at a temperature of 18-20°C.

[0064] (5) According to the data fed back by the online acrylamide concentration detector, when the acrylamide concentration reaches 50%, it is all collected from the third outlet at the top of the right half tower and enters the collection tank. It is then pumped by the pressurized pump to the enzyme separation membrane group and separated by the enzyme separation membrane group to obtain the third concentration product and biological enzyme. The material collected from the third outlet includes 27% solid biological enzyme cells and 73% acrylamide aqueous solution. The concentration of acrylamide remains unchanged before and after membrane separation, so the concentration of the first concentration product obtained is still 50%. The biological enzyme obtained in this step is returned to the reaction tower to participate in the initial reaction to generate acrylamide. The recycling rate of biological enzyme in this process is 95%.

[0065] In the continuous acrylamide preparation process of the integrated reaction device of this application, the amount of bio-enzyme required per ton of acrylamide is 140 kg, and the amount of bio-enzyme recycled is 133 kg, that is, the recycling rate of bio-enzyme can reach 95%. In the next acrylamide preparation process, adding 7 kg of bio-enzyme is enough to meet the production needs, that is, adding 5% of bio-enzyme can maintain the ideal yield, which greatly reduces the amount of bio-enzyme used.

[0066] Example 2

[0067] This embodiment provides a continuous process for preparing acrylamide, which is carried out in the same integrated reaction apparatus as in Example 1. The continuous process for preparing acrylamide includes the following steps:

[0068] (1) Acrylonitrile, pure water and biological enzymes are injected into the feed port of the left half tower by pressurizing the material pump according to the mass ratio of 350:1200:0.7. Gravity and feed pressure of 0.30 MPa cause the mixture to flow down along the packing in the left half tower and mix evenly. At the same time, acrylamide is generated by reaction under the temperature conditions of 18-20℃.

[0069] (2) According to the data fed back by the online acrylamide concentration detector, when the concentration of acrylamide in the reaction tower reaches 25%, some material is taken out from the first outlet of the reaction tower according to production needs. After entering the collection tank, it is pumped to the enzyme separation membrane group by the pressurized pump. The first concentration product and biological enzyme are separated by the enzyme separation membrane group. The material taken out from the first outlet includes 25% solid biological enzyme cells and 75% acrylamide aqueous solution. The concentration of acrylamide remains unchanged before and after membrane separation, so the concentration of the first concentration product is still 25%. 10% of the initial acrylonitrile dosage is added below the first outlet so that it continues to flow downward with the remaining material in the reaction tower and continues to react to generate acrylamide at a temperature of 18-20°C.

[0070] (3) According to the data fed back by the online acrylamide concentration detector, when the concentration of acrylamide in the reaction tower reaches 35%, some material is taken out from the second outlet of the reaction tower according to production needs. After entering the collection tank, it is pumped to the enzyme separation membrane group by the pressurized pump and separated by the enzyme separation membrane group to obtain the second concentration product and biological enzyme. The material taken out from the second outlet includes 23% solid biological enzyme cells and 77% acrylamide aqueous solution. The concentration of acrylamide remains unchanged before and after membrane separation, so the concentration of the second concentration product obtained is still 35%. The biological enzyme obtained in this step and in step (2) is injected into the bottom of the reaction tower and mixed with the remaining material. The recycling rate of biological enzyme in this process is ≥99%.

[0071] (4) When the above-mentioned biological enzyme and the remaining material mixture flows to the bottom of the reaction tower, the mixture turns into the right half of the tower. At the same time, 15% of the initial acrylonitrile dosage is added through the feed port. The material pump provides a pressure of 0.35 MPa as the driving force for the added material and the remaining material, so that the newly added acrylonitrile flows upward along the right half of the tower with the remaining material and continues to react to generate acrylamide at a temperature of 18-20°C.

[0072] (5) According to the data fed back by the online acrylamide concentration detector, when the acrylamide concentration reaches 50%, it is all collected from the third outlet at the top of the right half tower and enters the collection tank. It is then pumped by the pressurized pump to the enzyme separation membrane group and separated by the enzyme separation membrane group to obtain the third concentration product and biological enzyme. The material collected from the third outlet includes 25% solid biological enzyme cells and 75% acrylamide aqueous solution. The concentration of acrylamide remains unchanged before and after membrane separation, so the concentration of the first concentration product obtained is still 50%. The biological enzyme obtained in this step is returned to the reaction tower to participate in the initial reaction to generate acrylamide. The recycling rate of biological enzyme in this process is 90%.

[0073] In the continuous acrylamide preparation process of the integrated reaction device of this application, the amount of bio-enzyme required per ton of acrylamide is 130 kg, and the amount of bio-enzyme recycled is 117 kg, that is, the recycling rate of bio-enzyme can reach 90%. In the next acrylamide preparation process, adding 13 kg of bio-enzyme is enough to meet the production needs, that is, adding 10% of bio-enzyme can maintain the ideal yield, which greatly reduces the amount of bio-enzyme used.

[0074] Example 3

[0075] This embodiment provides a continuous process for preparing acrylamide, which is carried out in the same integrated reaction apparatus as in Example 1. The continuous process for preparing acrylamide includes the following steps:

[0076] (1) Acrylonitrile, pure water and biological enzymes are injected into the left half tower through the pressurization action of the material pump at a mass ratio of 350:1200:0.4. Gravity and 0.25 MPa feed pressure cause the mixture to flow down along the packing in the left half tower and mix evenly. At the same time, acrylamide is generated by reaction under the temperature conditions of 18-20℃.

[0077] (2) According to the data fed back by the online acrylamide concentration detector, when the concentration of acrylamide in the reaction tower reaches 20%, some material is taken out from the first outlet of the reaction tower according to production needs. After entering the collection tank, it is pumped to the enzyme separation membrane group by the pressurized pump. The first concentration product and biological enzyme are separated by the enzyme separation membrane group. The material taken out from the first outlet includes 30% solid biological enzyme cells and 70% acrylamide aqueous solution. The concentration of acrylamide remains unchanged before and after membrane separation, so the concentration of the first concentration product is still 20%. Acrylonitrile of the initial acrylonitrile dosage of 15% is added from below the first outlet so that it continues to flow downward with the remaining material in the reaction tower and continues to react to generate acrylamide under the temperature conditions of 18-20℃.

[0078] (3) According to the data fed back by the online acrylamide concentration detector, when the concentration of acrylamide in the reaction tower reaches 38%, some material is taken out from the second outlet of the reaction tower according to production needs. After entering the collection tank, it is pumped to the enzyme separation membrane group by the pressurized pump. The second concentration product and biological enzyme are separated by the enzyme separation membrane group. The material taken out from the second outlet includes 30% solid biological enzyme cells and 70% acrylamide aqueous solution. The concentration of acrylamide remains unchanged before and after membrane separation, so the concentration of the second concentration product is still 38%. The biological enzyme obtained in this step and step (2) is injected into the bottom of the reaction tower and mixed with the remaining material. The recycling rate of biological enzyme in this process is ≥99%.

[0079] (4) When the above-mentioned biological enzyme and the remaining material mixture flow to the bottom of the reaction tower, the mixture turns into the right half of the tower. At the same time, 13% of the initial acrylonitrile dosage is added through the feed port. The material pump provides a pressure of 0.30 MPa as the driving force for the added material and the remaining material, so that the newly added acrylonitrile flows upward along the right half of the tower with the remaining material and continues to react to generate acrylamide at a temperature of 18-20°C.

[0080] (5) According to the data fed back by the online acrylamide concentration detector, when the acrylamide concentration reaches 50%, it is all collected from the third outlet at the top of the right half tower and enters the collection tank. It is then pumped by the pressurized pump to the enzyme separation membrane group and separated by the enzyme separation membrane group to obtain the third concentration product and biological enzyme. The material collected from the third outlet includes 30% solid biological enzyme cells and 70% acrylamide aqueous solution. The concentration of acrylamide remains unchanged before and after membrane separation, so the concentration of the first concentration product obtained is still 50%. The biological enzyme obtained in this step is returned to the reaction tower to participate in the initial reaction to generate acrylamide. The recycling rate of biological enzyme in this process is 85%.

[0081] In the continuous acrylamide preparation process of the integrated reaction device of this application, the amount of bio-enzyme required per ton of acrylamide is 120 kg, and the amount of bio-enzyme recycled is 101 kg, that is, the recycling rate of bio-enzyme can reach 85%. In the next acrylamide preparation process, adding 19 kg of bio-enzyme is enough to meet the production requirements, that is, adding 16% of bio-enzyme can maintain the ideal yield, which greatly reduces the amount of bio-enzyme used.

[0082] Example 4

[0083] This embodiment provides a continuous process for preparing acrylamide, which is carried out in the same integrated reaction apparatus as in Example 1. The continuous process for preparing acrylamide includes the following steps:

[0084] (1) Acrylonitrile, pure water and biological enzymes are injected into the left half tower through the pressurization action of the material pump at a mass ratio of 350:1200:1. Gravity and 0.35 MPa feed pressure cause the mixture to flow down along the packing in the left half tower and mix evenly. At the same time, acrylamide is generated by reaction under the temperature conditions of 18-20℃.

[0085] (2) According to the data fed back by the online acrylamide concentration detector, when the concentration of acrylamide in the reaction tower reaches 30%, some material is taken out from the first outlet of the reaction tower according to production needs. After entering the collection tank, it is pumped to the enzyme separation membrane group by the pressurized pump. The first concentration product and biological enzyme are separated by the enzyme separation membrane group. The material taken out from the first outlet includes 20% solid biological enzyme cells and 80% acrylamide aqueous solution. The concentration of acrylamide remains unchanged before and after membrane separation, so the concentration of the first concentration product is still 30%. Acrylonitrile with an initial acrylonitrile dosage of 13% is added below the first outlet so that it continues to flow downward with the remaining material in the reaction tower and continues to react to generate acrylamide at a temperature of 18-20℃.

[0086] (3) According to the data fed back by the online acrylamide concentration detector, when the concentration of acrylamide in the reaction tower reaches 40%, some material is taken out from the second outlet of the reaction tower according to production needs. After entering the collection tank, it is pumped to the enzyme separation membrane group by the pressurized pump and separated by the enzyme separation membrane group to obtain the second concentration product and biological enzyme. The material taken out from the second outlet includes 27% solid biological enzyme cells and 73% acrylamide aqueous solution. The concentration of acrylamide remains unchanged before and after membrane separation, so the concentration of the second concentration product obtained is still 40%. The biological enzyme obtained in this step and in step (2) is injected into the bottom of the reaction tower and mixed with the remaining material. The recycling rate of biological enzyme in this process is ≥99%.

[0087] (4) When the above-mentioned biological enzyme and the remaining material mixture flow to the bottom of the reaction tower, the mixture turns into the right half of the tower. At the same time, 15% of the initial acrylonitrile dosage is added through the feed port. The material pump provides a pressure of 0.30 MPa as the driving force for the added material and the remaining material, so that the newly added acrylonitrile flows upward along the right half of the tower with the remaining material and continues to react to generate acrylamide under the temperature conditions of 18-20℃.

[0088] (5) According to the data fed back by the online acrylamide concentration detector, when the acrylamide concentration reaches 55%, it is all collected from the third outlet at the top of the right half tower and enters the collection tank. It is then pumped by the pressurized pump to the enzyme separation membrane group and separated by the enzyme separation membrane group to obtain the third concentration product and biological enzyme. The material collected from the third outlet includes 30% solid biological enzyme cells and 70% acrylamide aqueous solution. The concentration of acrylamide remains unchanged before and after membrane separation, so the concentration of the first concentration product obtained is still 55%. The biological enzyme obtained in this step is returned to the reaction tower to participate in the initial reaction to generate acrylamide. The recycling rate of biological enzyme in this process is 95%.

[0089] In the continuous acrylamide preparation process of the integrated reaction device of this application, the amount of bio-enzyme required per ton of acrylamide is 140 kg, and the amount of bio-enzyme recycled is 130 kg, that is, the recycling rate of bio-enzyme can reach 93%. In the next acrylamide preparation process, adding 10 kg of bio-enzyme is enough to meet the production needs, that is, adding 7% bio-enzyme can maintain the ideal yield, which greatly reduces the amount of bio-enzyme used.

[0090] Comparative Example 1

[0091] This comparative example provides a batch process for preparing acrylamide, which is carried out in a single reactor at a temperature maintained at 18–20°C. The batch process for preparing acrylamide includes the following steps:

[0092] (1) Pure water and biological enzymes are injected into the reactor at a mass ratio of 1200:1. Then, the material pump is started to pump acrylonitrile into the reactor, so that the materials in the reactor react with each other to generate acrylamide. During the reaction, the feeding speed of acrylonitrile is controlled by adjusting the flow rate, so that the acrylamide concentration increases with the increase of the total amount of acrylonitrile until the set concentration is reached and the reaction is stopped.

[0093] (2) After the reaction is completed, the material in the reactor is taken out and separated by an enzyme separation membrane to obtain bio-enzyme and acrylamide solution; the separated bio-enzyme is reused, and pure water and 40% to 70% bio-enzyme are added and injected into the reactor at one time for the next cycle of reaction.

[0094] Because the batch process for preparing acrylamide is carried out in a single reactor, only one concentration of acrylamide solution can be produced at the same time using the same equipment. Moreover, the material needs to be forcibly stirred during the reaction, which increases the energy consumption for acrylamide preparation. In addition, the bioenzyme recycling rate of the batch process is significantly lower than that of the preparation process in this application, and after 5 to 6 cycles of the batch process, the total amount of bioenzyme is discharged, and the amount of bioenzyme used also increases significantly.

[0095] Comparative Example 2

[0096] This comparative example provides a conventional continuous process for preparing acrylamide, which is carried out in multiple reactors connected in series. There are nine reactors in total, arranged from highest to lowest. Material is transferred between adjacent reactors by gravity flow based on height difference. Each reactor is equipped with a stirring device for agitating the material, and the temperature within each reactor is maintained at 18–20°C. The first reactor is the feed reactor, the fourth and seventh reactors are the addition reactors, and the third, sixth, and ninth reactors are the discharge reactors.

[0097] The traditional continuous process for preparing acrylamide includes the following steps:

[0098] (1) Acrylonitrile, pure water and biological enzyme are injected into the first reactor at a mass ratio of 350:1200:1. After the above materials are mixed evenly, the materials are transported to the second reactor to react and generate acrylamide.

[0099] (2) The material from the second reactor is transferred to the third reactor. When the material is further reacted in the third reactor until the concentration of acrylamide reaches 30%, part of the material is discharged from the outlet.

[0100] (3) The remaining material in the third reactor is continued to be transported to the fourth reactor, and acrylonitrile is added to it through the feed port, and the amount of acrylonitrile added is 10% of the initial amount of acrylonitrile; at this time, the material in the fourth reactor continues to react to generate acrylamide, and then is transported to the fifth reactor. After the reaction continues, it is further transported to the sixth reactor. When the concentration of acrylamide reaches 40%, part of the material is taken out from the outlet of the sixth reactor.

[0101] (4) Following the operation of step (3), add 10% of the initial acrylonitrile to the 7th reactor. After the reaction continues in the 8th reactor, the material with an acrylamide concentration of 50% is collected from the 9th reactor.

[0102] (5) The materials collected from the 3rd, 6th and 9th reactors are separated by an enzyme separation membrane to obtain biological enzymes and acrylamide solutions. The acrylamide concentrations in the acrylamide solutions obtained from the products of the 3rd, 6th and 9th reactors are 30%, 40% and 50%, respectively. The separated biological enzymes are stored in a cell tank. After the preparation process is completed, the biological enzymes stored in the cell tank are transported to the feed inlet of the first reactor for reuse.

[0103] This comparative example uses a traditional continuous method to prepare acrylamide. The required amount of bio-enzyme per ton of acrylamide is 120 kg. The bio-enzyme in the extracted material is separated, stored centrally, and then transported back to the first reactor for reuse. Ultimately, only 48 kg of bio-enzyme is reused, meaning the reuse rate is only 40%. In the next acrylamide preparation process, 72 kg of bio-enzyme needs to be added to meet production requirements. Under the same yield requirement, the amount of bio-enzyme used increases significantly. Furthermore, compared to the traditional continuous method, the preparation process in this application is highly concentrated in an integrated reaction device, offering advantages such as a short reaction cycle and small equipment footprint. Moreover, comparing energy consumption, the unit power consumption of the preparation process in this application is only 30%–45% of that of the traditional method, offering advantages such as low investment, low energy consumption, and high energy efficiency.

[0104] The implementation principle of this application is as follows: This application uses a reaction tower equipped with vertical baffles as the main reaction vessel. After the raw materials enter the reaction tower, they flow and mix along the packing, and acrylamide is produced at the same time. As the materials continue to flow and mix, the concentration of acrylamide gradually increases along its flow direction. At this time, acrylamide of different concentrations can be obtained from different outlets of the reaction tower, realizing the simultaneous extraction of acrylamide solutions of different concentrations from the same equipment, which is convenient for customers to extract acrylamide of different contents in stages according to their needs.

[0105] In this application, acrylamide with a concentration of less than 40% is synthesized in one half of the reaction tower; acrylamide with a concentration of more than 40% is synthesized in the other half of the reaction tower. This occupies half of the process space of the reaction tower, providing sufficient reaction time. At the same time, the bio-enzymes separated and reused by the enzyme separation membrane and the new acrylonitrile added to the bottom of the reaction tower effectively promote the generation of acrylamide, further improving the rate and yield of acrylamide generation.

[0106] The preparation process of this application is highly concentrated in an integrated reaction device, combining the advantages of both batch and continuous methods. On the one hand, it transforms the horizontally space-occupying multi-stage reaction equipment into a vertically space-occupying tower reactor, resulting in a shorter reaction cycle and less equipment footprint, thus reducing fixed asset investment. Simultaneously, the feed pressure at the top of the reaction tower propels the material to flow within the tower, naturally forming a homogenized state as it flows through the packing material, eliminating the need for additional power for stirring and reducing equipment operating energy consumption. On the other hand, after separation, the bio-enzymes from different concentrations of materials collected in different steps of this application are immediately recycled back into the reaction tower and participate in subsequent reactions. The amount of bio-enzymes required per ton of acrylamide is 120–140 mg / L. The amount of bio-enzyme recycled is 101-133 kg, meaning the recycling rate of bio-enzyme can reach 85%-95%. In the next acrylamide preparation process, adding 7-19 kg of bio-enzyme is sufficient to meet production needs. This not only achieves unlimited recycling of bio-enzyme but also makes good use of the robust effective life cycle of bio-enzyme. Thus, only 6-16% of new bio-enzyme needs to be added in each production cycle to maintain the ideal yield, greatly reducing the amount of bio-enzyme used. In addition, the bio-enzyme in this application adopts a method of separation and recycling at the same time, reducing intermediate bio-enzyme storage and the energy required for re-transportation from storage tanks to reactors. It has the advantages of low investment, low energy consumption, and high energy efficiency.

[0107] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A continuous process for preparing acrylamide, characterized in that: The preparation process is carried out in an integrated reaction device, which includes a reaction tower and a vertical partition fixed inside the reaction tower. The vertical partition divides the reaction tower into two half-towers, and the unclosed space between the vertical partition and the bottom of the reaction tower allows the two half-towers to communicate. The preparation process of the acrylamide includes the following steps: (1) Acrylonitrile, pure water and biological enzymes are injected from the top of one half of the reaction tower. The feed pressure causes the mixture to flow downward along the packing in the half tower, and at the same time, it reacts to generate acrylamide under stable temperature conditions. (2) When the concentration of acrylamide reaches 20% to 30%, some of the material is taken out from the first outlet of the reaction tower and separated by the enzyme separation membrane to obtain the first concentration product and biological enzyme. The remaining material in the reaction tower continues to flow downward and continues to react to generate acrylamide under stable temperature conditions. (3) When the concentration of acrylamide obtained from the reaction of the remaining materials reaches 30% to 40%, part of the material is taken out from the second outlet of the reaction tower and separated by the enzyme separation membrane to obtain the second concentration product and biological enzyme; the biological enzymes separated in steps (2) and (3) are injected into the reaction tower and mixed with the remaining materials at the corresponding injection positions. (4) When the above-mentioned bio-enzyme and the remaining material flow to the bottom of the reaction tower, acrylonitrile is added from the bottom of the reaction tower. At this time, the mixture turns to the other half of the reaction tower and flows upward along the packing. At the same time, it continues to react to generate acrylamide under stable temperature conditions. (5) When the material flows to the third outlet at the top of the other half of the reaction tower, the third concentration of product and bio-enzyme are obtained through the third outlet and the enzyme separation membrane group, and the bio-enzyme is reused to participate in the initial reaction.

2. The continuous method for preparing acrylamide according to claim 1, characterized in that: In step (1), the mass ratio of acrylonitrile, pure water, and biological enzyme is 350:1200:0.4-1.

3. The continuous method for preparing acrylamide according to claim 1, characterized in that: The feed pressure at the top of the reaction tower in step (1) and the feed pressure for adding acrylonitrile in step (4) are both 0.25 to 0.35 MPa; after a portion of the material is extracted from the first outlet in step (2), acrylonitrile is added, and the amount of acrylonitrile added in both steps (2) and (4) is 10% to 15% of the amount of acrylonitrile used in step (1).

4. The continuous method for preparing acrylamide according to claim 1, characterized in that: In steps (2) and (3), the pore size of the filter membrane of the enzyme separation membrane group is 0.05 μm, and the recycling rate of the biological enzyme is ≥99%; in step (5), the pore size of the filter membrane of the enzyme separation membrane group is 0.20 μm, and the recycling rate of the biological enzyme is 85% to 95%; the biological enzymes separated in steps (2) and (3) are injected into the reaction tower by means of separate injection or addition together.

5. The continuous process for preparing acrylamide and the integrated reaction apparatus according to claim 1, characterized in that: The reaction tower is equipped with multiple layers of heat exchange tube bundles arranged along the material flow direction, with one layer added for every 2-3°C increase, so that the temperature inside the reaction tower is stabilized at 18-20°C.

6. An integrated reaction apparatus for the continuous preparation of acrylamide as described in any one of claims 1-5, characterized in that: The integrated reaction device includes a reaction tower, a vertical baffle, a heat exchange tube bundle, and packing. The vertical baffle is fixed inside the reaction tower and divides the reaction tower into two half-towers. The unclosed space between the vertical baffle and the bottom of the reaction tower connects the two half-towers. One half-tower has a feed inlet at its top and the other half-tower has a discharge outlet at its top. The bottom of the reaction tower also has a feed outlet. The half-tower is fixedly equipped with multiple layers of heat exchange tube bundles along its length, and the packing is supported on the heat exchange tube bundles and filled between adjacent heat exchange tube bundles. At least two sampling outlets are provided at different height positions of the reaction tower body. Each sampling outlet is equipped with an enzyme separation membrane group for separating biological enzymes in the sampled material. The separated biological enzymes are injected into the reaction tower through a reflux pipe.

7. The integrated reaction apparatus for the continuous preparation of acrylamide according to claim 6, characterized in that: The bottom of the vertical baffle extends to half the height of the tower bottom head; the distance between the highest layer of packing and the top of the tower and the distance between the lowest layer of packing and the bottom of the tower are both 0.2 to 0.6 m.

8. The integrated reaction apparatus for the continuous preparation of acrylamide according to claim 6, characterized in that: The packing material inside the reaction tower is PP multifaceted hollow spheres, which are spherical PP packing materials with a porosity of 90% to 95%.

9. The integrated reaction apparatus for the continuous preparation of acrylamide according to claim 6, characterized in that: The heat exchange tube bundle is cooled by the inflow and outflow of cooling water, and a pneumatic regulating valve is installed on the heat exchange tube bundle to control the flow rate of the cooling water. A thermometer is installed in the reaction tower to monitor the temperature of the heat exchange tube bundle. The temperature of the reaction tower is controlled by adjusting the pneumatic regulating valve based on the feedback data from the thermometer.

10. The integrated reaction apparatus for the continuous preparation process of acrylamide according to claim 6, characterized in that: A collection tank for storing the collected material and a pressurizing pump for pressing the material in the collection tank into the enzyme separation membrane are provided between the reaction tower and the enzyme separation membrane. The pressure of the pressurizing pump enables the separation of acrylamide and biological enzyme in the enzyme separation membrane.

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