A supergravity device and method for intensifying continuous production of carboxylic acid from aldehyde oxidation

Abstract

This invention discloses a hypergravity apparatus and method for enhancing the continuous production of carboxylic acids through aldehyde oxidation. The apparatus includes a shell, a motor, gas-liquid inlet and outlet, a rotor, a gradient guide plate, and data acquisition instruments. The shell comprises a bottom rotor zone shell, a middle gradient guide zone shell, and a top bubbling zone shell. Firstly, the apparatus has virtually no gas phase space, effectively avoiding the explosion risk caused by gas phase cavities in conventional hypergravity apparatuses, thus possessing high intrinsic safety. Secondly, combined with intelligent calculation, the required bubble size is calculated based on the nonlinear changes in the reaction rate within the rotor zone, transition zone, and bubbling zone, and the hypergravity rotation speed is automatically adjusted to achieve bubble size modulation, ensuring efficient matching between the mass transfer rate and the intrinsic reaction rate. This improves reaction efficiency and product selectivity, significantly reducing the volume of the reactor and subsequent separation equipment. Furthermore, it reduces the use of expensive anti-corrosion materials, lowering investment costs.

Description

Technical Field

[0001] This invention relates to the field of aldehyde oxidation to acid production technology; specifically, it relates to a hypergravity device and method for enhancing the continuous production of carboxylic acids through aldehyde oxidation. Background Technology

[0002] Carboxylic acids are important organic chemical raw materials and intermediates, with wide applications in pharmaceuticals, pesticides, fragrances, polymer materials, and fine chemicals. Aldehyde oxidation is one of the important industrial routes for preparing carboxylic acids. Its basic principle is to use air or oxygen as an oxidant to oxidize aldehydes to the corresponding carboxylic acids in the presence of a catalyst. Especially with the rapid development of olefin hydroformylation technology for aldehyde production, aldehyde oxidation has received widespread attention from industry and academia in recent years. Currently, reactors used for aldehyde oxidation to carboxylic acids are mainly traditional gas-liquid contact equipment such as stirred tank reactors, bubble column reactors, and tubular reactors. However, these traditional reactors have inherent limitations when handling gas-liquid reaction systems using molecular oxygen as an oxidant: oxygen has low solubility in the aqueous or organic phases, resulting in slow gas-liquid mass transfer rates, which limit the reaction rate to the transfer of oxygen from the gas phase to the liquid phase. Therefore, measures such as increasing reaction pressure, increasing stirring speed, or adding gas distribution devices are usually required to improve gas-liquid mass transfer efficiency, but this leads to increased equipment investment, higher energy consumption, and increased operational safety risks.

[0003] Hypergravity technology is a relatively new process intensification technique that has emerged in recent years. Its core equipment is a rotating packed bed. This equipment typically generates a centrifugal force field tens to hundreds of times stronger than Earth's gravity through high-speed rotation. Conventional devices usually shear the liquid into extremely thin liquid films, microdroplets, or fine jets, causing a sharp increase in the gas-liquid interface and a significant improvement in the interface renewal rate. It boasts advantages such as small equipment size and high mass transfer efficiency. Currently, hypergravity technology has been industrially applied in fields such as nanomaterial preparation, waste gas purification, and distillation separation, and is gradually expanding into multiphase catalytic reaction processes.

[0004] In the field of aldehyde oxidation, researchers have attempted to introduce hypergravity technology. For example, Chinese patent application CN105233822A discloses a hypergravity catalyst for the esterification of aldehydes into carboxylic acid esters and its application. However, existing hypergravity reactors still have the following technical problems when used in the continuous industrial production of carboxylic acids from aldehyde oxidation: 1) Due to the dispersion of the liquid phase into liquid films, liquid lines, and droplets, there is a large gas phase space inside the reactor. This means that during the aldehyde oxidation process involving oxygen, the oxygen concentration may be within the explosion limit range, resulting in low intrinsic safety; 2) The residence time of the gas and liquid phases in the rotor of the rotating packed bed is too short. Although a shorter residence time is beneficial for fast reaction systems to avoid side reactions, aldehyde oxidation is a reaction process with a medium reaction rate. Especially when the reaction proceeds to the middle and late stages and the reactant concentration decreases, sufficient residence time is required to ensure the conversion rate. It is difficult to achieve the ideal conversion depth by simply relying on high-speed shearing in the rotor zone. 3) Although traditional bubbling bed reactors can provide a longer residence time, their gas-liquid mass transfer efficiency is much lower than that of hypergravity reactors, which results in the macroscopic reaction rate being limited by gas-liquid mass transfer. Moreover, the two are difficult to effectively integrate in terms of structure, and a single device cannot meet the dual requirements of enhanced mass transfer and extended residence time.

[0005] Therefore, how to design a hypergravity device that can achieve efficient gas-liquid mass transfer using hypergravity, provide sufficient residence time to ensure the conversion depth of the aldehyde oxidation reaction, and have good gas-liquid distribution characteristics and energy utilization efficiency, and systematically apply it to the process of continuous production of carboxylic acids from aldehyde oxidation, is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0006] The first technical problem this application aims to solve is to provide a hypergravity device for enhancing the continuous production of carboxylic acids through aldehyde oxidation. The hypergravity device of this invention has virtually no gas phase space inside, effectively avoiding the explosion risk caused by the presence of gas phase cavities in conventional droplet-type hypergravity devices, thus exhibiting high intrinsic safety. Furthermore, addressing the strong corrosiveness of aldehydes and carboxylic acids to the equipment, this device enhances gas-liquid mixing and mass transfer, and achieves efficient matching of intrinsic reaction rate and mass transfer rate in the rotor and bubbling zones. This improves reaction efficiency and product selectivity, reduces the volume of the reactor and subsequent separation sections, and enhances the safety of the production system. The second technical problem to be solved by this application is to provide a method for the continuous production of carboxylic acids by aldehyde oxidation using the above-mentioned supergravity device.

[0007] To solve the first technical problem mentioned above, the present invention adopts the following technical solution: A hypergravity device for enhancing the continuous production of carboxylic acids by aldehyde oxidation includes a shell, a motor, a gas-liquid inlet, a rotor, a gas-liquid outlet, a rotor, a gradient guide plate, and instruments or meters for data acquisition. The housing includes a rotor region housing at the bottom, a gradually changing flow guide region housing in the middle, and a bubbling region housing at the top; The rotor region is located inside the rotor housing, and a rotor is installed within the rotor region. The gradual flow guide zone is located inside the shell. A gradual flow guide plate is fixed on the inner wall of the shell to convert tangential momentum into radial momentum. The bubbling area is located inside the shell. The motor is fixedly connected to the rotor through a shaft passing through the housing; the rotor is equipped with packing; the gas-liquid inlet is connected to a gas-liquid initial distributor located in the cavity in the middle of the packing through a pipe; The gas-liquid inlet is located at the bottom of the rotor housing; The gas-liquid outlet is located at the top of the bubbling zone shell; The instruments or meters used for data acquisition include a gas flow meter installed at the gas inlet, a liquid flow meter installed at the liquid inlet, and concentration, temperature, and pressure sensors installed at the outlet positions of the rotor zone, the gradual flow guide zone, and the bubbling zone.

[0008] Preferably, the shell is provided with a heat exchange medium inlet and a heat exchange medium outlet, and a heat exchange jacket is provided inside the shell; the heat exchange medium inlet is located at the bottom of the rotor zone shell, the heat exchange medium outlet is located at the upper part of the bubbling zone shell, and the heat exchange medium inlet and the heat exchange medium outlet are connected to the heat exchange jacket inside the shell.

[0009] Preferably, the supergravity device further includes an intelligent calculation and control system for efficient matching of mass transfer reactions, the system comprising a data acquisition module, an intelligent calculation module, a deviation verification module, and a control execution module.

[0010] More preferably, the data acquisition module is used to acquire the liquid inlet flow rate, the gas inlet flow rate, and the temperature, pressure, raw material carboxylic acid content, and product aldehyde content at three locations near the outlet of the rotor zone, the gradual flow guide zone, and the bubbling zone.

[0011] More preferably, the intelligent computing module calculates the intrinsic reaction rate by substituting the detected raw material and product concentrations, temperature, and pressure parameters into the built-in intrinsic kinetic model; to achieve efficient matching of mass transfer and reaction, it calculates the required mass transfer coefficient based on the condition that the mass transfer rate equals the reaction rate; then, based on the pre-trained artificial neural network model, correlation, or mass transfer calculation model between the mass transfer coefficient and bubble size in the reactor, it back-calculates the required bubble size; finally, based on the relationship between the bubble size and rotor speed in the reactor obtained through simulation or experimental calibration, it outputs the optimal target speed with the goal of minimizing the error at each position.

[0012] More preferably, the deviation verification module is used to calculate the relative deviation between the actual operating speed and the target speed obtained by intelligent calculation, and to determine whether the deviation is greater than a preset threshold: if it is less than or equal to the threshold, the actual speed is maintained and operation continues; if it is greater than the threshold, the control execution module is activated.

[0013] More preferably, the control execution module receives signals through the frequency converter driver, and then adjusts the speed of the motor and rotor to achieve the adjustment of the bubble size; after the adjustment is completed, it returns to the data acquisition module, intelligent calculation module and deviation verification module to re-acquire, calculate and verify the data until the deviation is less than or equal to the preset threshold, and finally maintains the actual speed operation.

[0014] Preferably, the heat exchange medium is one of heat transfer oil, water, ethylene glycol, and propylene glycol.

[0015] Preferably, the shell of the gradient guide zone is in the shape of a frustum, and the angle between the generatrix of the frustum and the horizontal direction is 30~150°.

[0016] More preferably, the angle between the generatrix of the frustum and the horizontal direction is 45~135°; the inner surface of the shell of the gradient guide zone is a hydrophilic surface with a contact angle of less than 30°.

[0017] Preferably, the gradient guide plate has 3 to 6 blades arranged circumferentially, and the surface of the gradient guide plate is provided with a number of radial holes.

[0018] Preferably, the rotor structure is either an integral rotating structure or a stator-rotor structure, and the rotor contains 1 to 5 layers of packing material. Both the packing material and the rotor surface are hydrophilic surfaces with a contact angle of less than 30°.

[0019] Preferably, the diameter ratio of the rotor region housing and the bubbling region housing is 5:1-1:5, or 4:1-1:4, or 3:1-1:3, or 2:1-1:2.

[0020] To solve the second technical problem mentioned above, the present invention adopts the following technical solution: A method for the continuous production of carboxylic acids by aldehyde oxidation using the above-mentioned hypergravity device includes the following steps: S1. The catalyst and aldehyde raw material are mixed evenly in the catalyst preparation tank, and then transported to the gas-liquid inlet of the supergravity device by the feed pump; at the same time, air or oxygen is transported to the same gas-liquid inlet by the compressor. S2. After initial mixing at the gas-liquid inlet of the hypergravity device, the gas phase and the catalyst-containing liquid phase continue to enter the center of the hypergravity rotor. Under the high-speed and strong turbulent action of the rotor packing, the gas phase is dispersed into micro-nano bubbles with an average size of 10 nm to 500 μm. After redistribution through the gradual flow guiding zone, the gas and liquid phases enter the bubbling zone. The gas phase and the catalyst-containing liquid phase fully contact and react in the bottom rotor zone, the middle gradual flow guiding zone, and the top bubbling zone. The speed of the hypergravity rotor is set and optimized by an intelligent calculation and control system that efficiently matches the mass transfer reaction. S3. After the gas and liquid phases leave the top of the supergravity device, they enter the gas-liquid separator. After preliminary separation, the gas phase enters the venting pipeline; the liquid phase is cooled by the heat exchanger, and part of it is circulated to the gas-liquid inlet of the supergravity device by the circulating pump. The remaining crude product is extracted by the extraction pump, and the heat of reaction is removed through the outer jacket of the device and the circulating heat exchanger. S4. The crude product is separated by a separation unit to obtain a carboxylic acid product.

[0021] Preferably, the reaction pressure in the hypergravity reactor is 0.1~5 MPa, the reaction temperature is 20~200℃, the hypergravity rotation speed is 500~3000 r / min, and the catalyst is one or more carboxylates of transition metals such as Co, Mn, Fe, Ce, Ni, and Cu, with a concentration of 0~200 ppm, where a concentration of 0 represents no catalyst added; preferably, the catalyst concentration is 50~100 ppm.

[0022] Any range described in this invention includes the endpoint, any value between the endpoints, and any subrange consisting of the endpoint or any value between the endpoints.

[0023] Unless otherwise specified, all raw materials used in this invention can be obtained commercially, and the equipment used in this invention can be conventional equipment in the relevant field or refer to existing technology in the relevant field.

[0024] Compared with the prior art, the present invention has the following beneficial effects: 1) The reactor device of the present invention has no separate gas phase space, which can effectively avoid the risk of gas phase cavity explosion limit in conventional droplet-type hypergravity devices, and has high inherent safety.

[0025] 2) This invention combines intelligent computing to automatically adjust the speed of the supergravity rotation to achieve the adjustment of bubble size, thereby achieving an efficient match between the mass transfer rate and the intrinsic reaction rate, improving reaction efficiency and product selectivity, and significantly reducing the volume of the reactor and subsequent separation section and other supporting equipment.

[0026] 3) Due to the strong corrosiveness of carboxylic acids, this method can reduce the use of expensive anti-corrosion equipment materials and lower investment costs. Attached Figure Description

[0027] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Figure 1 A schematic diagram of the supergravity device of the present invention is shown; Figure 2 This diagram shows the gradual flow guide zone of the present invention when the gradual angle is 45°; Figure 3 A schematic diagram of the gradient guide zone of the present invention is shown when the gradient angle is 135°. Figure 4 A logical schematic diagram of the intelligent computing and control system for efficient mass transfer reaction matching of the present invention is shown. Figure 5 A schematic diagram of a continuous hypergravity system for enhancing the oxidation of aldehydes to carboxylic acids, as shown in Embodiment 1 of the present invention, is presented. Detailed Implementation

[0028] To more clearly illustrate the present invention, the following description, in conjunction with preferred embodiments, further clarifies the invention. Those skilled in the art should understand that the specific descriptions below are illustrative rather than restrictive, and should not be construed as limiting the scope of protection of the present invention.

[0029] See Figures 1-3 As shown, as one aspect of the present invention, a hypergravity device 100 for enhancing the continuous production of carboxylic acid by aldehyde oxidation includes a shell 7, a motor 1, gas-liquid inlets 22 and 23, a rotor 3, a gas-liquid outlet 4, a gradient guide plate 6, and an instrument or meter 8 for data acquisition. The housing 7 includes a rotor region housing 71 at the bottom, a gradually changing flow guide region housing 72 in the middle, and a bubbling region housing 73 at the top; The rotor region is located within the rotor housing 71, and a rotor 3 is installed within the rotor region. The gradually changing flow zone shell 72 is a gradually changing flow zone. A gradually changing flow plate 6 is fixed on the inner wall of the gradually changing flow zone shell 72, so that the gas-liquid mixture after entering the bubbling zone is more evenly distributed in the radial direction. At the same time, it separates the bottom rotor zone and the bubbling zone, converts tangential momentum into radial momentum, weakens the formation of vortices in the bubbling zone, and improves energy utilization efficiency. The bubbling zone is located inside the shell 73. The bubbling zone is used to increase the residence time of the gas-liquid mixture, especially when the reactant concentration is low at the end of the reaction, thereby improving the reaction conversion rate. During use, the rotor region housing 71, the gradual flow guiding region housing 72, and the bubbling region housing 73 of the present invention are filled with a gas-liquid mixture, and there is no separate gas phase space.

[0030] The motor 1 is fixedly connected to the rotor 3 through the housing 7 via the rotating shaft 11; the rotor 3 is provided with packing 31; the gas-liquid inlet includes a gas inlet 22 and a liquid inlet 23, and the gas-liquid inlets 22 and 23 are connected to the gas-liquid initial distributor 21 provided in the cavity in the middle of the packing 31 via pipes; The gas-liquid inlets 22 and 23 are located at the bottom of the rotor housing 71; The gas-liquid outlet 4 is located at the top of the bubbling zone shell 73.

[0031] A gas flow meter 81 is installed on the gas inlet 22, and a liquid flow meter 82 is installed on the liquid inlet 23. Concentration, temperature and pressure sensors 83, 84 and 85 are installed at the outlet positions of the rotor area, the gradual flow guiding area and the bubbling area.

[0032] According to certain embodiments of the present invention, a heat exchange medium inlet 74 and a heat exchange medium outlet 75 are provided on the housing 7, and a heat exchange jacket 76 is provided inside the housing 7; the heat exchange medium inlet 74 is provided at the bottom of the rotor region housing 71, and the heat exchange medium outlet 75 is provided at the upper part of the bubbling region housing 73, and the heat exchange medium inlet 74 and the heat exchange medium outlet 75 are connected to the heat exchange jacket 76 inside the housing 7.

[0033] See Figure 4 As shown, according to some embodiments of the present invention, the hypergravity device further includes an intelligent calculation and control system for efficient matching of mass transfer reactions, the system including a data acquisition module, an intelligent calculation module, a deviation verification module, and a control execution module.

[0034] See Figure 4 As shown, the data acquisition module is used to acquire the liquid inlet flow rate, the gas inlet flow rate, and the temperature, pressure, raw material carboxylic acid content, and product aldehyde content at three locations near the outlet of the rotor zone, the gradual flow guiding zone, and the bubbling zone.

[0035] See Figure 4 As shown, the intelligent computing module calculates the intrinsic reaction rate by substituting the detected raw material and product concentrations, temperature, and pressure parameters into the built-in intrinsic kinetic model. R I The calculation formula is as follows: R I = kC A a P O2 b (Equation 1) in, k It is the oxidation reaction rate constant; C A It is the concentration of aldehydes; PO2 is the partial pressure of oxygen, and a and b are the corresponding reaction orders.

[0036] To achieve efficient matching between mass transfer and reaction, the required mass transfer coefficient is calculated based on the condition that the mass transfer rate equals the reaction rate. k L a ) T The calculation formula is as follows: ( k L a ) T = R I / H ( P O2 - P *) (Equation 2) in, H It is the Henry coefficient; P * is the partial pressure of the gas phase when it is in equilibrium with the bulk oxygen concentration in the liquid phase; P O2 It is the actual partial pressure of oxygen in the bulk gas phase.

[0037] Then, based on a pre-trained artificial neural network model, correlation equation, or mass transfer calculation model relating the mass transfer coefficient and bubble size within the reactor, the required bubble size is calculated. Taking the mass transfer correlation equation as an example, the calculation formula is as follows: ( k L a ) T = f ( d b , D L , σ L , ρ L , ρ G , μ L , μ G , D c…) (Equation 3) in, d b It refers to the bubble size; D L It is the diffusion coefficient of oxygen in the liquid phase; ρ L and ρ G These are the densities of the liquid phase and the gas phase, respectively. μ L and μ G These are the liquid phase viscosity and the gas phase viscosity, respectively. D c is the reactor diameter.

[0038] Finally, based on the relationship between bubble size and rotor speed at different locations within the reactor, obtained through simulation or experimental calibration, the required rotor speed can be calculated from the bubble size. The formula for calculating bubble size is as follows: d b,i = α i N βi (Equation 4) in, α i It is the proportionality coefficient; β i It is a power exponent characterizing the sensitivity to the influence of rotational speed, where N is the rotor speed.

[0039] With the goal of minimizing the errors at each position, the optimal target rotational speed is output. The objective is to minimize the weighted sum of squared errors, as expressed below: E ( N )=∑ w i ( α i N βi - d b,T ) 2 (Equation 5) in, w i These are the weights of each position; d b,T It refers to the target bubble size required at each location.

[0040] See Figure 4 As shown, the deviation verification module is used to calculate the relative deviation between the actual operating speed and the target speed obtained by intelligent calculation, and to determine whether the deviation is greater than a preset threshold: if it is less than or equal to the threshold, the actual speed is maintained and operation continues; if it is greater than the threshold, the control execution module is activated; the speed deviation calculation formula is as follows: δ = ( N T - N A ) / N T (Equation 6) in, N T It is the target rotational speed; NA This is the actual operating speed.

[0041] See Figure 4 As shown, the control execution module receives signals through the frequency converter driver, and then adjusts the speed of the motor and rotor to achieve the adjustment of the bubble size. After the adjustment is completed, it returns to the data acquisition module, intelligent calculation module and deviation verification module to re-acquire, calculate and verify the data until the deviation is less than or equal to the preset threshold, and finally maintains the actual speed operation.

[0042] According to certain embodiments of the present invention, the heat exchange medium is one of heat transfer oil, water, ethylene glycol, and propylene glycol.

[0043] According to certain embodiments of the present invention, the gradient flow guide area housing 72 is in the shape of a frustum, and the angle (gradient angle) between the generatrix of the frustum and the horizontal direction is 30~150°; more preferably, the angle between the generatrix of the frustum and the horizontal direction is 45~135°; the inner surface of the gradient flow guide area housing 72 is a hydrophilic surface with a contact angle of less than 30°.

[0044] According to some embodiments of the present invention, the gradient guide plate 6 is provided with 3 to 6 blades axially, and the surface of the gradient guide plate 6 is provided with a plurality of radial holes.

[0045] According to certain embodiments of the present invention, the rotor 3 is an integral rotating structure or a stator-rotor structure, and the rotor is filled with 1 to 5 layers of packing. Both the packing and the rotor surface are hydrophilic surfaces with a contact angle of less than 30°.

[0046] According to certain embodiments of the present invention, the diameter ratio of the rotor region housing 71 and the bubbling region housing 73 is 5:1 to 1:5, or 4:1 to 1:4, or 3:1 to 1:3, or 2:1 to 1:2.

[0047] As another aspect of the present invention, a method for the continuous production of carboxylic acids by aldehyde oxidation using the above-mentioned hypergravity device includes the following steps: S1. The catalyst and aldehyde raw material are mixed evenly in the catalyst preparation tank 200, and then conveyed to the gas-liquid inlet of the hypergravity device 100 by the feed pump 300; at the same time, air or oxygen is conveyed to the same gas-liquid inlet by the compressor 400. S2. After initial mixing at the gas-liquid inlet of the hypergravity device, the gas phase and the catalyst-containing liquid phase continue to enter the rotor center of the hypergravity device. Under the high-speed and strong turbulent action of the rotor packing, the gas phase is dispersed into micro-nano bubbles with an average size of 10 nm to 500 μm. After redistribution through the gradual flow guiding zone, the gas and liquid phases enter the bubbling zone. The gas phase and the catalyst-containing liquid phase fully contact and react in the bottom rotor zone, the middle gradual flow guiding zone, and the top bubbling zone. S3. After the gas and liquid phases leave the top of the hypergravity device, they enter the gas-liquid separator 500. After preliminary separation, the gas phase enters the venting pipeline; the liquid phase is cooled by the heat exchanger 600, and part of it is circulated to the gas-liquid inlet of the hypergravity device 100 by the circulating pump 700. The remaining crude product is extracted by the extraction pump 800. The heat of reaction is removed through the heat exchange jacket and the circulating heat exchanger on the shell of the hypergravity device. S4. The crude product is separated by a separation unit to obtain a carboxylic acid product.

[0048] According to certain embodiments of the present invention, in step 2), the reaction pressure inside the hypergravity device is 0.1~5 MPa, the reaction temperature is 20~200℃, the rotor speed is 500~3000 r / min, and the catalyst is one or more carboxylates of transition metals such as Co, Mn, Fe, Ce, Ni, and Cu, with a concentration of 0~200 ppm, where a concentration of 0 represents no catalyst added; preferably, the catalyst concentration is 50~100 ppm. Example 1

[0049] Adopting such Figure 1 The centrifugal device shown enables the continuous production of n-butyraldehyde to n-butyric acid through oxidation. The system utilizes an outer jacket and liquid-phase circulation for heat transfer, as described in the process flow diagram. Figure 5 As shown, the specific steps are as follows: 1) The catalyst and aldehyde raw material are uniformly mixed in the catalyst preparation tank to make the catalyst content 50 ppm. The mixture is then pumped to the gas-liquid inlet of the supergravity device via a feed pump. At the same time, air is pumped to the same gas-liquid inlet via a compressor, and the molar ratio of oxygen to n-butyraldehyde is controlled to be 0.6. 2) After initial mixing of the gas phase and the catalyst-containing liquid phase at the gas-liquid inlet of the hypergravity device, the mixture enters the center of the hypergravity rotor. Under the action of high-speed, strong turbulence from the rotor packing, the gas phase is dispersed into micro- and nano-bubbles; 3) After the gas and liquid phases are redistributed in the gradually changing flow zone, they enter the bubbling zone and fully contact and react in the bottom rotor zone, the middle gradually changing flow zone and the top bubbling zone. 4) The gas and liquid phases after the reaction leave from the top of the centrifugal device and enter the gas-liquid separator. After initial separation, the gas phase enters the venting line; the liquid phase is cooled by the heat exchanger, and part of the liquid phase is circulated to the gas-liquid inlet of the centrifugal device by the circulating pump. The remaining crude product is collected by the extraction pump and sampled for analysis.

[0050] The heat of reaction was removed through the heat exchange jacket and circulating heat exchanger of the hypergravity device, controlling the reactor temperature at approximately 55 °C, with an inlet-outlet temperature difference of ≤5 °C and an internal pressure of 0.2 MPa. The hypergravity device, optimized by an intelligent calculation and control system for efficient mass transfer and reaction matching, rotated at 1000 r / min, with a liquid phase residence time of 30 min. After the system stabilized, outlet sampling analysis showed that the conversion rate of n-butyraldehyde was 99.8%, and the selectivity of n-butyric acid was 98.6%. Example 2

[0051] Adopting such Figure 1 The centrifugal device shown enables the continuous production of 2-ethylhexanol to 2-ethylhexanoic acid through oxidation. The system utilizes an outer jacket and liquid-phase circulation for heat transfer, as described in the process flow diagram. Figure 5 As shown, the specific steps are as follows: 1) The catalyst and aldehyde feedstock are uniformly mixed in a catalyst preparation tank to achieve a catalyst concentration of 100 ppm. The mixture is then pumped to the gas-liquid inlet of the centrifugal device. Simultaneously, air is supplied to the same gas-liquid inlet via a compressor, controlling the molar ratio of oxygen to n-butyraldehyde to be 0.7. 2) After initial mixing of the gas phase and the catalyst-containing liquid phase at the gas-liquid inlet of the hypergravity device, the mixture enters the center of the hypergravity rotor. Under the action of high-speed, strong turbulence from the rotor packing, the gas phase is dispersed into micro- and nano-bubbles; 3) After the gas and liquid phases are redistributed in the gradually changing flow zone, they enter the bubbling zone and fully contact and react in the bottom rotor zone, the middle gradually changing flow zone and the top bubbling zone. 4) The gas and liquid phases after the reaction leave from the top of the centrifugal device and enter the gas-liquid separator. After initial separation, the gas phase enters the venting line; the liquid phase is cooled by the heat exchanger, and part of the liquid phase is circulated to the gas-liquid inlet of the centrifugal device by the circulating pump. The remaining crude product is collected by the extraction pump and sampled for analysis.

[0052] The heat of reaction is removed through the heat exchange jacket and circulating heat exchanger of the centrifugal device, controlling the reactor temperature at approximately 30℃, with an inlet-outlet temperature difference of ≤5℃ and an internal pressure of 0.3 MPa. The rotor speed, optimized by an intelligent calculation and control system for efficient mass transfer and reaction matching, is 1200 r / min, and the liquid phase residence time is 40 min. After the system stabilizes, outlet sampling analysis shows that the conversion rate of 2-ethylhexanal is 99.7%, and the selectivity of 2-ethylhexanoic acid is 97.4%. Comparative Example 1

[0053] Adopting such Figure 4The experimental procedure shown is the same as in Example 1, except that the reactor was replaced with a conventional bubble reactor for the continuous production of n-butyraldehyde to n-butyric acid. The heat transfer method, liquid phase residence time, catalyst content, and the feed molar ratio of oxygen to n-butyraldehyde were all the same. The reactor temperature was also controlled at 55°C, with an inlet-outlet temperature difference of ≤5°C, and the reactor pressure was 0.2 MPa. After the system stabilized, the outlet sample analysis showed that the conversion rate of n-butyraldehyde was 77.3%, and the selectivity of n-butyric acid was 88.5%.

[0054] It is evident that when a conventional bubbling reactor is used to replace the hypergravity device of this invention, the conversion rate of n-butyraldehyde and the selectivity of n-butyric acid both decrease significantly. Comparative Example 2

[0055] Adopting such Figure 4 The experimental procedure shown is the same as in Example 1, except that the reactor was replaced with a stirred tank bubbling reactor for the continuous production of n-butyraldehyde to n-butyric acid. The heat transfer method, liquid phase residence time, catalyst content, and the feed molar ratio of oxygen to n-butyraldehyde were all the same. The reactor temperature was also controlled at 55°C, the inlet and outlet temperature difference was ≤5°C, the reactor pressure was 0.2 MPa, and the stirring motor speed was 1000 r / min. After the system stabilized, the outlet sample analysis results showed that the conversion rate of n-butyraldehyde was 84.8%, and the selectivity of n-butyric acid was 93.1%.

[0056] It is evident that after replacing the hypergravity device of this invention with a stirred tank bubbling reactor, the conversion rate of n-butyraldehyde decreased significantly, and the selectivity of n-butyric acid decreased significantly. Comparative Example 3

[0057] Adopting such Figure 4 The experimental procedure shown is the same as in Example 1, except that the reactor was replaced with a simple combination of a hypergravity reactor and a bubbling bed without a gradual flow guide zone, enabling continuous production of n-butyraldehyde to n-butyric acid. The heat transfer method, liquid phase residence time, catalyst content, and the feed molar ratio of oxygen to n-butyraldehyde were all the same. The reactor temperature was also controlled at 55°C, the inlet and outlet temperature difference was ≤5°C, the reactor pressure was 0.2 MPa, and the hypergravity rotation speed was 1000 r / min. After the system stabilized, the outlet sample analysis showed that the conversion rate of n-butyraldehyde was 86.1%, and the selectivity of n-butyric acid was 95.2%.

[0058] It is evident that after replacing the hypergravity device of this invention with a reactor consisting of a simple combination of hypergravity and a bubbling bed without a gradual flow zone, the conversion rate of n-butyraldehyde decreases significantly, and the selectivity of n-butyric acid decreases markedly. Comparative Example 4

[0059] Adopting such Figure 4The experimental procedure shown is the same as in Example 2, except that the reactor was replaced with a conventional bubble reactor for the continuous production of 2-ethylhexanal to 2-ethylhexanoic acid. The heat transfer method, liquid phase residence time, catalyst content, and the feed molar ratio of oxygen to n-butyraldehyde were all the same. The reactor temperature was also controlled at 30°C, with an inlet-outlet temperature difference of ≤5°C, and the reactor pressure was 0.3 MPa. After the system stabilized, the outlet sample analysis results showed that the conversion rate of 2-ethylhexanal was 76.4%, and the selectivity of n-butyric acid was 86.2%.

[0060] It is evident that replacing the hypergravity device with a conventional bubbling reactor significantly reduced the conversion rate of 2-ethylhexanal and the selectivity of 2-ethylhexanoic acid. Comparative Example 5

[0061] Adopting such Figure 4 The experimental procedure shown is the same as in Example 2, except that the reactor was replaced with a stirred tank bubbling reactor for the continuous production of 2-ethylhexanal to 2-ethylhexanoic acid. The heat transfer method, liquid phase residence time, catalyst content, and the feed molar ratio of oxygen to n-butyraldehyde were all the same. The reactor temperature was also controlled at 30°C, the inlet and outlet temperature difference was ≤5°C, the reactor pressure was 0.3 MPa, and the stirring motor speed was 1200 r / min. After the system stabilized, the outlet sample analysis results showed that the conversion rate of 2-ethylhexanal was 82.2%, and the selectivity of 2-ethylhexanoic acid was 91.4%.

[0062] It is evident that after replacing the hypergravity device of this invention with a stirred tank bubbling reactor, the conversion rate of 2-ethylhexanal decreased significantly, and the selectivity of 2-ethylhexanoic acid decreased significantly. Comparative Example 6

[0063] Adopting such Figure 4 The experimental procedure shown is the same as in Example 2, except that the reactor was replaced with a simple combination of a gravity reactor and a bubbling bed without a gradual flow guide zone for the continuous production of 2-ethylhexanal to 2-ethylhexanoic acid. The heat transfer method, liquid phase residence time, catalyst content, and the feed molar ratio of oxygen to n-butyraldehyde were all the same. The reactor temperature was also controlled at 30°C, the inlet and outlet temperature difference was ≤5°C, and the reactor pressure was 0.3 MPa. After the system stabilized, the outlet sampling analysis showed that the conversion rate of 2-ethylhexanal was 85.6%, and the selectivity of 2-ethylhexanoic acid was 94.3%.

[0064] Therefore, it is evident that replacing the hypergravity device of this invention with a simple combination of hypergravity reactor and bubbling bed without a gradual flow guide zone significantly reduces the conversion rate of 2-ethylhexanal and noticeably decreases the selectivity of 2-ethylhexanoic acid.

[0065] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is impossible to exhaustively list all embodiments here. All obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A hypergravity apparatus for enhancing the continuous production of carboxylic acids through aldehyde oxidation, characterized in that: Includes housing, motor, gas-liquid inlet, rotor, gas-liquid outlet, gradient guide plate, and instruments or meters for data acquisition; The housing includes a rotor region housing at the bottom, a gradually changing flow guide region housing in the middle, and a bubbling region housing at the top; The rotor region is located inside the rotor housing, and a rotor is installed within the rotor region. The gradual flow guide zone is located inside the shell. A gradual flow guide plate is fixed on the inner wall of the shell to convert tangential momentum into radial momentum. The bubbling area is located inside the shell. The motor is fixedly connected to the rotor through a shaft passing through the housing; the rotor is equipped with packing; the gas-liquid inlet is connected to a gas-liquid initial distributor located in the cavity in the middle of the packing through a pipe; The gas-liquid inlet is located at the bottom of the rotor housing; The gas-liquid outlet is located at the top of the bubbling zone shell; The instruments or meters used for data acquisition include a gas flow meter installed at the gas inlet, a liquid flow meter installed at the liquid inlet, and concentration, temperature, and pressure sensors installed at the outlets of the rotor zone, the gradual flow guide zone, and the bubbling zone.

2. The hypergravity device according to claim 1, characterized in that: The shell is provided with a heat exchange medium inlet and a heat exchange medium outlet, and a heat exchange jacket is provided inside the shell; the heat exchange medium inlet is located at the bottom of the rotor area shell, and the heat exchange medium outlet is located at the upper part of the bubbling area shell, and the heat exchange medium inlet and the heat exchange medium outlet are connected to the heat exchange jacket inside the shell.

3. The hypergravity device according to claim 1, characterized in that: The hypergravity device also includes an intelligent calculation and control system for efficient matching of mass transfer reactions. This system includes a data acquisition module, an intelligent calculation module, a deviation verification module, and a control execution module. The data acquisition module is used to acquire liquid flow rate, air flow rate, and temperature, pressure, raw material carboxylic acid content, and product aldehyde content at three locations near the outlet of the rotor zone, the gradual flow guiding zone, and the bubbling zone. The intelligent computing module calculates the intrinsic reaction rate by substituting the detected raw material and product concentrations, temperature, and pressure parameters into the built-in intrinsic kinetic model. To achieve efficient matching of mass transfer and reaction, it calculates the required mass transfer coefficient based on the condition that the mass transfer rate equals the reaction rate. Then, based on the pre-trained artificial neural network model, correlation, or mass transfer calculation model between the mass transfer coefficient and bubble size in the reactor, it back-calculates the required bubble size. Finally, based on the relationship between the bubble size and rotor speed in the reactor obtained through simulation or experimental calibration, it outputs the optimal target speed with the goal of minimizing the error at each position. The deviation verification module is used to calculate the relative deviation between the actual operating speed and the target speed obtained by intelligent calculation, and to determine whether the deviation is greater than a preset threshold: if it is less than or equal to the threshold, the actual speed is maintained and operation continues; if it is greater than the threshold, the control execution module is activated. The control execution module receives signals through a frequency converter driver, and then adjusts the speed of the motor and rotor to achieve the adjustment of bubble size; After adjustment, the data acquisition module, intelligent calculation module, and deviation verification module are returned to re-acquire, calculate, and verify the data until the deviation is less than or equal to the preset threshold, and finally the actual speed is maintained.

4. The hypergravity device according to claim 2, characterized in that: The heat exchange medium is one of heat transfer oil, water, ethylene glycol, and propylene glycol.

5. The hypergravity device according to claim 1, characterized in that: The shell of the gradient guide zone is in the shape of a frustum, and the angle between the generatrix of the frustum and the horizontal direction is 30~150°.

6. The hypergravity device according to claim 5, characterized in that: The angle between the generatrix of the frustum and the horizontal direction is 45~135°; the inner surface of the shell of the gradually changing flow guide zone is a hydrophilic surface with a contact angle of less than 30°.

7. The hypergravity device according to claim 1, characterized in that: The gradient guide plate has 3 to 6 blades arranged circumferentially, and the surface of the gradient guide plate has several radial holes.

8. The hypergravity device according to claim 1, characterized in that: The rotor structure is either an integral rotating structure or a stator-rotor structure. The rotor contains 1 to 5 layers of packing material. Both the packing material and the rotor surface are hydrophilic surfaces with a contact angle of less than 30°.

9. The hypergravity device according to claim 1, characterized in that: The diameter ratio of the rotor region housing and the bubbling region housing is 5:1 to 1:5, or 4:1 to 1:4, or 3:1 to 1:3, or 2:1 to 1:

2.

10. A method for the continuous production of carboxylic acids from aldehydes using any one of the hypergravity devices of claims 1-8, characterized in that, Includes the following steps: S1. The catalyst and aldehyde raw material are mixed evenly in the catalyst preparation tank, and then transported to the gas-liquid inlet of the supergravity device by the feed pump; at the same time, air or oxygen is transported to the same gas-liquid inlet by the compressor. S2. After initial mixing at the gas-liquid inlet of the hypergravity device, the gas phase and the catalyst-containing liquid phase continue to enter the center of the hypergravity rotor. Under the high-speed and strong turbulent action of the rotor packing, the gas phase is dispersed into micro-nano bubbles with an average size of 10 nm to 500 μm. After redistribution through the gradual flow guiding zone, the gas and liquid phases enter the bubbling zone. The gas phase and the catalyst-containing liquid phase fully contact and react in the bottom rotor zone, the middle gradual flow guiding zone, and the top bubbling zone. The speed of the hypergravity rotor is set and optimized by an intelligent calculation and control system that efficiently matches the mass transfer reaction. S3. After the gas and liquid phases leave the top of the supergravity device, they enter the gas-liquid separator. After preliminary separation, the gas phase enters the venting pipeline; the liquid phase is cooled by the heat exchanger, and part of it is circulated to the gas-liquid inlet of the supergravity device by the circulating pump. The remaining crude product is extracted by the extraction pump, and the heat of reaction is removed through the outer jacket of the device and the circulating heat exchanger. S4. The crude product is separated by a separation unit to obtain a carboxylic acid product; Preferably, in step 2), the reaction pressure inside the hypergravity device is 0.1~5 MPa, the reaction temperature is 20~200℃, the hypergravity rotation speed is 500~3000 r / min, and the catalyst is one or more of the carboxylates of transition metals such as Co, Mn, Fe, Ce, Ni, and Cu, with a concentration of 0~200 ppm, where a concentration of 0 represents no catalyst added; preferably, the catalyst concentration is 50~100 ppm.

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