Synthetic butyraldehyde low-pressure recovery device and synthetic recovery method thereof

Abstract

The invention provides a low-pressure recovery device for synthetic butyraldehyde. The low-pressure recovery device comprises a slurry bed reactor and a recovery module, a discharge port of the slurry bed reactor is connected with the first-stage evaporator through a first-stage pressure release valve, and a gas-slurry mixture is output from the bottom of the first-stage evaporator to the stripping tower for separation. Materials at the bottom of the stripping tower enter a second-stage evaporator through a second-stage pressure release valve to gasify butyraldehyde, and gasified products are conveyed to a catalyst cooling tower to be cooled and then enter a separation tower to separate a catalyst. The separation tower bottom catalyst and the cooling tower bottom catalyst are conveyed to a regeneration tank for regeneration, and the regenerated catalyst returns to the slurry bed reactor through a circulation pipeline. According to the device, through multi-stage evaporation, steam stripping separation and catalyst cyclic regeneration, the butyraldehyde synthesis efficiency is improved, high-purity separation of butyraldehyde and cyclic utilization of raw materials are realized.

Description

Technical Field

[0001] The present invention belongs to the field of chemical engineering and technology, and particularly relates to a low-pressure recovery device for synthesizing butyraldehyde and a synthesis method thereof. Background Art

[0002] As an important organic chemical raw material, butyraldehyde plays an important role in many industrial production fields and has extensive application value. However, there are many problems to be solved in the traditional butyraldehyde synthesis process. In the raw material recovery link, the traditional process has high energy consumption, which not only increases the cost but also reduces the efficiency, contrary to the current development concept of energy conservation, emission reduction, and improving resource utilization rate. At the same time, in the traditional process, on the one hand, the catalyst recovery link needs to be achieved through high-temperature distillation or solvent extraction. Not only is the energy consumption high, but the catalyst's activity rapidly decays due to carbon deposition, sintering, etc. during repeated cycling. Even after the catalyst is deactivated, its catalytic performance drops significantly, resulting in a decrease in the reaction rate and product yield. In order to ensure the normal operation of production, frequent replenishment or replacement is required, and the significantly increased production cost also limits the continuity and stability in the production process; on the other hand, the separation efficiency of unreacted syngas raw materials (CO and H 2 2) and light component by-products is low, and the raw materials in the traditional flash distillation process cannot be effectively recovered, resulting in both resource waste and an increased burden on tail gas treatment.

[0003] In view of this, the present invention is specifically proposed. Summary of the Invention

[0004] The first object of the present invention is to provide a low-pressure recovery device for synthesizing butyraldehyde. By combining a slurry bed reactor and a recovery module, this device realizes the improvement of butyraldehyde synthesis efficiency, the high-purity separation of butyraldehyde, and the recycling of unreacted raw materials. At the same time, it reduces the deactivation rate of the catalyst, resulting in a higher recovery rate of the catalyst, reduces the consumption of the catalyst during use, improves resource utilization rate, and reduces energy consumption and costs.

[0005] The second object of the present invention is to provide a synthesis recovery method realized by using the low-pressure recovery device for synthesizing butyraldehyde. This method uses the above device for the synthesis and low-pressure recovery of butyraldehyde, which can improve the product yield and the effect of raw material recovery.

[0006] In order to achieve the above objects of the present invention, the following technical solutions are specifically adopted: The present invention provides a low-pressure recovery device for synthesizing butyraldehyde, including: a slurry bed reactor, a recovery module; One side of the slurry bed reactor is provided with a feed inlet, and a discharge outlet is arranged above the side and connected to the starting point first-stage pressure relief valve of the recovery module through a first pipeline. After the slurry mixture passes through the first-stage pressure relief valve through the first pipeline, it is transported to a first-stage evaporator; The bottom outlet of the primary evaporator is connected to the feed inlet on one side of the stripping column through a second pipeline, and the second pipeline is used to send the gas-slurry mixture to the stripping column for separation; The outlet of the stripping column is connected to the feed inlet at the top of the secondary evaporator through a third pipeline provided with a secondary pressure relief valve to transport the slurry mixture at the bottom of the stripping column to the secondary evaporator for the gasification of butyraldehyde; The bottom of the secondary evaporator is provided with a discharge port, and the discharge port is communicated with the feed inlet on the side wall of the catalyst cooling tower through a fourth pipeline to cool the catalyst in the gasified butyraldehyde; The top discharge port of the catalyst cooling tower is communicated with the feed inlet on the side wall of the separation column through a fifth pipeline for separating the catalyst in butyraldehyde; the bottom discharge port of the catalyst cooling tower is connected to the catalyst regeneration tank through a sixth pipeline; The top of the separation column is provided with a product sampling outlet, and the bottom is provided with a discharge port, which is connected to the catalyst regeneration tank through a seventh pipeline to transport the catalyst in the separation column to the catalyst regeneration tank for catalyst regeneration treatment; The bottom of the catalyst regeneration tank is provided with an outlet, and the bottom of the slurry bed reactor is provided with a circulation port. The outlet and the circulation port are connected through a circulation pipeline to return the catalyst at the bottom of the catalyst regeneration tank to the slurry bed reactor.

[0007] In the low-pressure recovery device for synthesizing butyraldehyde of the present invention, the slurry bed reactor is the reaction area for butyraldehyde synthesis, which generates a slurry mixture (product butyraldehyde, unreacted raw material propylene, and catalyst). This slurry mixture is then transported through a pipeline to the recovery module for subsequent processing. On the recovery module, the evaporator and the pressure relief valve are cleverly combined to achieve multi-stage pressure reduction. This not only helps to gradually reduce the pressure in the device but also, in coordination with the catalyst cooling tower, further reduces the inactivation rate during the catalyst recycling process, effectively improving the catalyst recovery efficiency. In the traditional process, the pressure in the evaporator is 11 - 14 atm, and it is necessary to use high-temperature steam at 140 °C for countercurrent heat exchange, resulting in a concentration of a large amount of heat. While generating condensate water at 110 °C, it also causes the temperature in about 2 / 3 of the evaporator area to rise above 120 °C. This high-temperature environment greatly accelerates the inactivation of the catalyst and significantly increases the production cost. The synergistic effect of the multi-stage evaporator and the pressure relief valve of the present invention not only effectively controls the pressure but also further improves the separation efficiency of the catalyst and the product and reduces the energy consumption. At the same time, the evaporator of the present invention uses co-current heat exchange to effectively control the temperature difference between the catalyst particles and the heat exchange tube wall, avoiding local overheating phenomena, thereby reducing the inactivation rate of the catalyst during the recovery process. Compared with the high temperature of the traditional process, only steam at 120 °C and 0.2 MPa is required for heating in the evaporator of the present invention; it promotes the closed-loop use of synthetic raw materials and fundamentally reduces the consumption cost of the catalyst. ( Figure 2 ) Preferably, it further includes a catalyst separation tank, which is located between the stripping tower and the secondary evaporator; a swirl separation area composed of multiple groups of cyclones is provided in the middle of the catalyst separation tank to separate the catalyst and the liquid in the slurry mixture by centrifugal force; the bottom of the catalyst separation tank is set as a conical collection tank to collect part of the catalyst by gravity sedimentation; a second outlet is provided at the bottom of the conical collection tank, and the second outlet is connected to the feed port of the catalyst regeneration tank through a seventh pipeline to transport the catalyst to the catalyst regeneration tank.

[0008] A catalyst separation tank is also provided in this device to effectively separate the catalyst and the liquid before the slurry mixture enters the secondary evaporator. Through a swirl separation area composed of 2 - 3 groups of cyclones, using the principle of centrifugal force, the catalyst and the liquid in the slurry mixture are efficiently separated, improving the catalyst recovery rate. The bottom is set as a conical collection tank, which is beneficial for the catalyst to be collected by gravity sedimentation. The conical structure enables the catalyst to more easily gather at the bottom of the tank, facilitating subsequent transportation and regeneration processing. This is the preliminary separation of the catalyst particles.

[0009] Preferably, a spray layer is provided in the washing area at the top of the catalyst regeneration tank, and an ultrasonic separator is embedded in the side wall of the tank to cover the entire washing area to remove impurities on the surface of the catalyst. A centrifuge and a drying channel are also provided at the bottom of the tank to separate the spray liquid and enable the recycling of the catalyst.

[0010] In this solution, through the steps of washing, separating and drying, the catalyst regeneration tank can efficiently regenerate the catalyst. The regenerated catalyst flows back to the slurry bed reactor through the circulation pipeline, realizing the recycling of the catalyst, reducing the production cost, and at the same time reducing the generation of waste.

[0011] Preferably, the catalyst cooling tower is composed of a column and a box body. The inlet of the box body is arranged in the middle, and an intercepting scraper area is arranged above the inlet. A spiral pipe in a circular spiral shape is arranged at the bottom of the intercepting scraper area; the catalyst cooling tower is provided with a water inlet and a water outlet; the spiral pipe penetrates through the column and enters the box body below, and a landslide is inclined in the box body. The outlet of the landslide is connected to the catalyst regeneration tank through an eighth pipeline for transporting the cooled catalyst to the catalyst regeneration tank.

[0012] In the catalyst cooling tower of this device, when the gas-phase butyraldehyde enters the column body through the inlet carrying catalyst particles, the catalyst will rise with the airflow. When this airflow passes through the interception scraper area, due to the blocking effect of the scraper, most of the catalyst particles are effectively intercepted. These intercepted catalyst particles slide slowly downward along the inclined plane at the bottom of this area under the action of gravity and finally enter the annular spiral pipeline arranged below. Inside the spiral pipeline, the catalyst particles flow down orderly and slowly along the spiral path, which not only ensures that the catalyst particles can be fully dispersed but also greatly extends their contact time with the cooling water. During the process of the catalyst particles sliding in the spiral pipeline, the cooling water is introduced through the water inlet of the cooling tower and exchanges heat with the catalyst particles, effectively reducing the temperature of the catalyst and thus avoiding the sintering deactivation problem that may be caused by high-temperature retention. As the catalyst particles continue to slide in the spiral pipeline, they will eventually reach the end of the spiral pipeline and fall onto the inclined landslide inside the box. To ensure that too many catalyst particles do not accumulate on the landslide, in addition to having a certain inclination angle, a vibration motor is arranged on the landslide, which will vibrate periodically to further promote the sliding and dispersion of the catalyst particles. The design of the landslide enables the catalyst particles to slide smoothly to the landslide outlet under the action of gravity and be smoothly transported to the catalyst regeneration tank through the eighth pipeline. This not only extends the service life of the catalyst particles but also improves the recovery rate, reduces the cost expenditure caused by frequent catalyst replacement, and improves the efficiency and sustainability of the entire production process. The gas-phase butyraldehyde discharges from the discharge port at the top of the catalyst cooling tower with the remaining catalyst particles and enters the separation tower through the fifth pipeline, where the gas-phase butyraldehyde and the remaining catalyst particles are further effectively separated. This process ensures the purity of the gas-phase butyraldehyde and at the same time recovers the trace catalyst particles that may be carried out by the airflow.

[0013] Preferably, a gas extraction port is arranged at the top of the stripping tower and it has a layered structure with a wire mesh area, a washing liquid supply area, and a packing area arranged in sequence from top to bottom, so that the vaporized propylene and the raw material gas are discharged and recovered from the gas extraction port, and the gas extraction port is connected to the first condenser through a pipeline.

[0014] In this device, most of the vaporized propylene, a small amount of hydrogen and carbon monoxide bubbles, and the slurry mixture containing the catalyst enter the stripping column to achieve effective separation of the gas and the slurry mixture. Since a certain amount of bubbles will be generated during the synthesis process of the device of the present invention, these bubbles will not only drive the catalyst particles to rise together during the rising process, which is not conducive to the separation and recovery of raw materials. Therefore, in the present invention, a wire mesh area and a packing area are arranged in the stripping column to jointly act to achieve effective separation of the catalyst particles and the gas. The wire mesh area is specially configured as a multi-layer structure. The design of the multi-layer wire mesh can not only effectively intercept and break the rising bubbles, reduce their driving effect on the catalyst particles, but also promote the full contact and mass transfer between the gas and liquid phases through the fine mesh structure, thereby improving the separation efficiency. At the same time, the multi-layer wire mesh can also avoid the blockage problem caused by the agglomeration of catalyst particles into larger particles on the surface of the single-layer wire mesh. To further optimize the separation effect and the recovery of the catalyst, the packing area is arranged below the wire mesh area, and a certain distance is maintained between the packing and the wire mesh. The packing, with its high specific surface area and excellent mass transfer performance, plays an important role in intercepting solid catalyst particles, preventing them from rising with the foam and blocking the wire mesh. The packing layer can capture and disperse most of the catalyst particles, while allowing the gas and a small amount of liquid to pass through, forming conditions conducive to gas-liquid mass transfer. The wire mesh layer focuses on breaking the remaining foam after passing through the packing layer to ensure that the foam content in the gas discharged from the gas outlet is extremely low, thereby improving the purity of the recovered gas.

[0015] Preferably, a mass transfer intensification unit is arranged at the bottom of the slurry bed reactor. The microbubbles ejected by the mass transfer intensification unit are provided with a gas outlet at the top for discharging the unreacted gas raw materials during the reaction. The gas outlet is connected to the inlet of the raw material recovery tank through the ninth pipeline to send the gas raw materials into the raw material recovery tank for storage.

[0016] In the slurry bed reactor of this device, a mass transfer intensification unit is used to optimize the process of butyraldehyde synthesis. By introducing carbon monoxide and hydrogen, the unit significantly increases the contact area between the gas and liquid phases through its internal structure design. At the same time, a nanoparticle catalyst is used, which further improves the reaction efficiency by virtue of its high specific surface area and unique electronic structure. When hydrogen and carbon monoxide pass through the intensification unit, they are converted into micron-sized bubbles and sent into the butyraldehyde synthesis reactor, which greatly increases the phase boundary area of the reaction system. The increase in the phase boundary area enables the reaction of propylene, carbon monoxide and hydrogen in the reaction tower to be more complete under a lower operating pressure, thereby significantly increasing the yield of butyraldehyde. The gas outlet at the top of the slurry bed reactor is used to discharge most of the unreacted carbon monoxide and hydrogen. After being treated by the flash evaporation technology, they can be directly recycled for the next round of reaction of butyraldehyde synthesis, thus realizing the maximization of resource utilization and the effective reduction of costs.

[0017] Preferably, the outlet of the product is connected to the inlet of the butyraldehyde storage tank through an output pipeline, and a second condenser is provided on the output pipeline to send the condensed butyraldehyde to the butyraldehyde storage tank.

[0018] In this device, the butyraldehyde vapor flowing out of the product outlet after separation is fully condensed by the second condenser, so that pure butyraldehyde flows into the butyraldehyde storage tank in a liquid state.

[0019] Preferably, a reflux port is provided on the butyraldehyde storage tank, and the reflux port is connected to the port of the washing liquid supply area through a reflux pipeline to return part of the butyraldehyde to the washing liquid supply area; multiple spray layers are arranged along the side wall of the stripping column in the washing liquid supply area, and the spray layer is composed of a washing liquid conveying pipeline and a plurality of uniformly distributed spray heads; a washing liquid storage tank is provided on the reflux pipeline to facilitate the continuous supply of the washing liquid.

[0020] In this device, part of the butyraldehyde in the butyraldehyde storage tank is used as part of the washing liquid for reflux, which not only realizes the recycling of resources, but also enhances the functionality and flexibility of the washing liquid supply area. When part of the butyraldehyde returns to the washing liquid supply area through the reflux port and the reflux pipeline, the multi-layer designed spray layer further ensures that the washing liquid can be evenly and fully sprayed inside the stripping column, further enhancing the separation and purification effect of the stripping column. The washing liquid can be sprayed out to cover the packing area and the wire mesh area, forming a liquid film. This liquid film can not only intercept a small amount of catalyst particles and impurities rising with the bubbles, but also remove the catalyst particles remaining above the wire mesh and the packing for washing, so that they fall to the bottom of the gas washing tower along with the butyraldehyde liquid and then are recycled along the process.

[0021] Preferably, a catalyst tank is provided on the circulation pipeline to circulate the catalyst in the catalyst regeneration tank back to the catalyst tank, and a feed port is provided on one side of the catalyst tank to supplement the catalyst.

[0022] Catalysts play a crucial role in the butyraldehyde synthesis reaction. They can accelerate the reaction rate and improve the yield and purity of the product. However, with long-term use during the reaction, the activity of some catalysts may gradually decrease or even become inactivated. Therefore, regularly replacing or regenerating the catalyst is the key to maintaining production efficiency. The regenerated catalyst returns to the catalyst tank through the circulation pipeline and is used again for the catalytic reaction. This recycling method not only reduces the waste of the catalyst, but also reduces the production cost. In this way, not only can the regenerated catalyst be stored, but when the amount of catalyst in the catalyst tank is insufficient or needs to be replaced, new catalyst can be added through the feed port to ensure that there is always enough catalyst in the reaction device.

[0023] The mass transfer intensification unit of the present invention belongs to the prior art. Those skilled in the art can understand that there are different types of units, such as pneumatic, hydraulic, and pneumatic-hydraulic linkage types. However, the selection between these types mainly depends on the specific working conditions. As for the connection method between the unit and the slurry bed reactor and other equipment, including the connection structure and connection position, it needs to be determined according to the structure of the slurry bed reactor and will not be specifically limited here.

[0024] In the present invention, flow control valves, pressure monitoring devices, etc. are provided on both the pipelines and the pipe circuits to ensure the reasonable flow of materials and the stable control of process parameters.

[0025] The present invention also provides a synthesis recovery method using a synthetic butyraldehyde low-pressure recovery device, including the following steps: CO, H2, propylene, and a catalyst are sequentially introduced into the slurry bed reactor for reaction. After the reaction is complete, the catalyst is recovered through the recovery module, and the product is obtained.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) By combining the slurry bed reactor with the recovery module, the present invention realizes the efficient utilization of the catalyst and the maximum recovery of resources. The slurry bed reactor provides ideal conditions for the catalytic reaction with its good mixing effect and high mass transfer and heat transfer rates, ensuring the efficient progress of the reaction. At the same time, the introduction of the recovery module enables the effective separation and recovery of unreacted raw materials, by-products, and the catalyst generated during the reaction process, improving the recovery rate of raw materials, avoiding resource waste and environmental pollution.

[0027] (2) By combining the evaporator and the pressure relief valve, the present invention forms a multi-stage pressure relief effect, reducing the boiling point of butyraldehyde. Butyraldehyde can be effectively vaporized at a relatively low temperature; the multi-stage step-by-step release of pressure will not cause a large amount of inactivation of the catalyst due to high temperature and rapid pressure changes during the vaporization process. With the assistance of a catalyst cooling tower, after butyraldehyde is vaporized, the catalyst carrying heat is promptly cooled, effectively reducing the temperature of the catalyst, reducing the reduction of catalyst activity and structural damage caused by temperature, and further improving the recovery rate of the catalyst.

[0028] (3) The recovery module in the present invention is designed with a multi-stage recovery process, enabling the fine separation and purification of each raw material component, ensuring that the butyraldehyde generated during the synthesis process and all the input raw materials can be maximally recovered and reused.

[0029] (4)The synthesis and recovery method of the low-pressure recovery device for synthesizing butyraldehyde provided by the present invention reduces production costs and the environmental burden. Through the recycling of the catalyst and the recycling and reuse of resources, the consumption of new catalysts and raw materials is reduced, and the production cost is lowered. At the same time, the waste and emissions generated during the recovery process are effectively controlled, reducing environmental pollution and conforming to the concept of sustainable development. Description of the Drawings

[0030] By reading the following detailed description of the preferred embodiments, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present invention. Moreover, throughout the drawings, the same reference numerals are used to represent the same components. In the drawings: Figure 1 is a structural diagram of a low-pressure recovery device for synthesizing butyraldehyde according to the present invention; Figure 2 is a comparison diagram of the evaporator (B) of the present invention and the evaporator (A) of the traditional process.

[0031] Reference Numerals in the Drawings: 1 - Slurry Bed Reactor, 2 - Primary Evaporator, 3 - Stripping Tower, 4 - Catalyst Separation Tank, 5 - Secondary Evaporator, 6 - Catalyst Cooling Tower, 7 - Separation Tower, 8 - Catalyst Regeneration Tank, 9 - Butyraldehyde Storage Tank, 10 - Catalyst Tank, 11 - Primary Pressure Relief Valve, 12 - Secondary Pressure Relief Valve, 13 - First Condenser, 14 - Second Condenser, 15 - Raw Material Recovery Tank, 16 - First Pipeline, 17 - Second Pipeline, 18 - Third Pipeline, 19 - Fourth Pipeline, 20 - Fifth Pipeline, 21 - Sixth Pipeline, 22 - Seventh Pipeline, 23 - Eighth Pipeline, 24 - Ninth Pipeline, 25 - Tenth Pipeline, 26 - Circulation Pipeline, 27 - Return Pipeline, 28 - Wash Liquid Storage Tank, 31 - Output Pipeline, 101 - Mass Transfer Enhancement Unit, 102 - Synthesis Gas Feed Pipe, 103 - Propylene Feed Pipe, 301 - Wire Mesh Area, 302 - Wash Liquid Supply Area, 303 - Packing Area, 601 - Intercepting Scraper Area, 602 - Spiral Pipeline, 603 - Landslide. Detailed Embodiments

[0032] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and specific embodiments. However, those skilled in the art will understand that the following described embodiments are some embodiments of the present invention, rather than all embodiments, and are only used to illustrate the present invention and should not be construed as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention. For those conditions not specified in the embodiments, they shall be carried out according to conventional conditions or conditions recommended by the manufacturer. For reagents or instruments not specified by the manufacturer, they are all conventional products that can be obtained through commercial purchase.

[0033] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0034] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installation", "connection", "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0035] The technical solution of the present invention provides a low-pressure recovery device for synthesizing butyraldehyde, including: a slurry bed reactor 1 and a recovery module. In the traditional butyraldehyde synthesis system, the pressure in the butyraldehyde synthesis reactor is relatively high, usually maintained at 18 - 19 atm, and the contact area between the gas-liquid two phases is limited. This situation greatly limits the full contact between the reactants, thereby affecting the progress of the reaction. In order to ensure the continuous progress of the reaction, it is often necessary to raise the temperature of the reactor by 10 - 15 °C. However, increasing the temperature will have an adverse effect on the recovery effect of the catalyst, but not increasing the temperature will lead to incomplete reaction and a decrease in the yield of the product.

[0036] The present invention adds a mass transfer enhancement component 101 in the slurry bed reactor 1. During the synthesis process, this component can convert carbon monoxide and hydrogen into nanoscale bubbles. These tiny bubbles significantly increase the contact area between the gas and liquid phases, enabling the slurry bed reactor 1 of the present device to achieve a more efficient reaction under relatively low pressure (11 - 14 atm). Due to the improved reaction efficiency, there is no need to increase the reaction temperature. In this way, not only is the recovery efficiency of the catalyst particles improved, but also the energy consumption required for the recovery of the catalyst particles is greatly saved. While achieving low-energy consumption recovery, the recovery rate of the catalyst particles is also significantly increased. The reacted material will first pass through a first-stage pressure relief valve 11 in the recovery module to reduce the pressure to 4 atm. In the first-stage evaporator 2, as the pressure decreases, the temperature required for evaporation also decreases accordingly. Then, the material is further depressurized through a second-stage pressure relief valve 12, and the pressure drops to 1.3 atm, which further reduces the evaporation temperature in the second-stage evaporator 12. Compared with traditional evaporators, the evaporators in the device of the present invention operate at a lower temperature. Under such a pressure environment, the boiling point of butyraldehyde is relatively low, and it can be evaporated only by heating with 0.2 MPa steam at 120 °C, avoiding the problem of a large amount of catalyst deactivation caused by high temperature. The catalyst cooling tower 6 connected after the second-stage evaporator cools the catalyst passing through the evaporator again, further reducing the catalyst deactivation rate and improving the catalyst recovery effect. Therefore, compared with the traditional technology, the device of the present invention reduces the catalyst deactivation rate and improves the yields of raw materials and products by gradually reducing the pressure and supplementing with the form of a catalyst cooling tower, so that the temperature in the whole device will not be too high.

[0037] In order to more clearly illustrate the technical solutions in the present invention, the following will be described in the form of specific embodiments.

[0038] Example 1 Refer to Figure 1 As shown, the present invention is a low-pressure recovery device for synthesizing butyraldehyde. The synthesis and recovery process of butyraldehyde is as follows: Carbon monoxide, hydrogen, and propylene are introduced into the mass transfer enhancement unit 101 in the slurry bed reactor through the synthesis gas feed pipe 102 and the propylene feed pipe 103 respectively. The mass transfer enhancement unit 101 breaks carbon monoxide and hydrogen into micron-scale bubbles and then reacts with propylene. The pressure in the slurry bed reactor 1 is controlled at 12 atm. After the reaction is completed, the unreacted carbon monoxide and hydrogen will be discharged from the gas outlet at the top of the slurry bed reactor 1, enter the raw material recovery tank 15 through the ninth pipe 24 for flash evaporation treatment and storage, and be used for the next round.

[0039] The remaining product butyraldehyde, unreacted raw material propylene and the catalyst flow out in a slurry state and enter the recovery module; first, the above-mentioned slurry mixture is depressurized to 4 atm through the first pressure relief valve 11 on the first pipeline 16 and then introduced into the first evaporator 2, where most of the propylene is vaporized.

[0040] The vaporized propylene and the remaining slurry mixture enter the stripping process through the second pipeline 17. In the stripping column 3, most of the vaporized propylene, as well as a small amount of hydrogen and carbon monoxide bubbles, are discharged through the gas extraction outlet at the top through the wire mesh 301 and the packing area 303. It passes through the tenth pipeline 25 and is condensed by the first condenser 13 on the pipeline, and then flows into the raw material recovery tank 15 for storage, facilitating the use in the next round of synthesis.

[0041] The butyraldehyde product, heavy component impurities and catalyst mixture discharged from the bottom of the stripping column 3 enter the catalyst separation tank 4 to separate the catalyst. The separated catalyst is transported from the second outlet at the bottom of the catalyst separation tank 4 through the seventh pipeline 22 to the catalyst regeneration tank 8. Using the cyclone separation area composed of 3 cyclones and the gravity sedimentation of the conical collection tank, the catalyst is separated from the mixture. The separated catalyst is transported from the second outlet at the bottom of the catalyst separation tank 4 through the seventh pipeline 22 to the catalyst regeneration tank for regeneration treatment to remove the heavy component impurities on the surface.

[0042] The remaining mixture is depressurized to 1.3 atm through the third pipeline 18 equipped with a second pressure relief valve 12 and sent to the second evaporator 5, where it is heated with 0.2 MPa steam to vaporize the butyraldehyde for subsequent purification and collection.

[0043] The vaporized butyraldehyde and the remaining catalyst particles enter the catalyst cooling tower 6 through the fourth pipeline 19. In the interception scraper area 601, the gas reacts with the scraper during the rising process to prevent the catalyst particles from continuing to rise with the airflow. The scraper effectively intercepts most of the catalyst particles, and the intercepted catalyst particles slide down to the spiral pipeline 602. When the catalyst slides and on the landslide 603, it can be cooled by cooling water to further reduce the deactivation rate of the catalyst particles. The cooled catalyst particles are sent to the catalyst regeneration tank 8 through the eighth pipeline 23.

[0044] The gaseous butyraldehyde exits through the discharge port at the top of the catalyst cooling tower 6, carrying a small portion of catalyst particles, and enters the separation tower 7 through the fifth pipeline 20. Further separation of the gaseous butyraldehyde from the residual catalyst particles is carried out, and the vaporized butyraldehyde is purified. The pure butyraldehyde is discharged from the product sampling port at the top of the separation tower 7 and is condensed and liquefied through the output pipeline 31 and the second condenser 14 on the pipeline and sent to the butyraldehyde storage tank 9. In this step, the purity of the gaseous butyraldehyde is ensured, and at the same time, a small amount of catalyst particles that may be carried out by the gas flow are recovered.

[0045] The catalyst particles separated in the separation tower 7 are transported to the catalyst regeneration tank 8 through the sixth pipeline 21. The catalyst regeneration tank 8 processes the transported catalyst, and the processed catalyst particles are transported to the catalyst tank 10 for storage through the circulation pipeline 26, and the heavy component impurities are discharged from the tank body. When butyraldehyde needs to be synthesized in the next round, it flows back to the slurry bed reactor 1 through the circulation pipeline 26.

[0046] Part of the liquid butyraldehyde in the butyraldehyde storage tank 9 will enter the washing liquid storage tank 28 through the reflux pipeline 27. When the washing liquid supply area 302 of the stripping tower 3 needs it, it enters the washing liquid supply area 302 from the washing liquid storage tank 28 through the reflux pipeline 27 to remove the catalyst particles on the wire mesh area 301 and the packing area 303 to prevent blockage.

[0047] Example 2 The present invention is a low-pressure recovery device for synthesizing butyraldehyde. In this embodiment, the synthesis and recovery process of butyraldehyde is as follows: Carbon monoxide, hydrogen, and propylene are introduced into the mass transfer intensification unit 101 in the slurry bed reactor through the synthesis gas feed pipe 102 and the propylene feed pipe 103 respectively. The mass transfer intensification unit 101 breaks carbon monoxide and hydrogen into micron-sized bubbles and reacts with propylene. The pressure of the slurry bed reactor 1 is controlled at 14 atm. After the reaction is completed, the unreacted carbon monoxide and hydrogen are discharged from the gas outlet at the top of the slurry bed reactor 1 and enter the raw material recovery tank 15 through the ninth pipeline 24 for flash evaporation treatment and storage for use in the next round.

[0048] The remaining product butyraldehyde, unreacted raw material propylene, and catalyst flow out in a slurry state and enter the recovery module; first, the above-mentioned slurry mixture is depressurized to 4 atm through the first-stage pressure relief valve 11 on the first pipeline 16 and then introduced into the first-stage evaporator 2. In the first-stage evaporator 2, most of the propylene is vaporized.

[0049] The vaporized propylene and the remaining slurry mixture enter the stripping process through the second pipeline 17. In the stripping column 3, most of the vaporized propylene, as well as a small amount of hydrogen and carbon monoxide bubbles, are discharged through the gas extraction outlet at the top via the wire mesh 301 and the packing area 303. They pass through the tenth pipeline 25 and are condensed by the first condenser 13 on the pipeline, and then flow into the raw material recovery tank 15 for storage, facilitating the use in the next round of synthesis.

[0050] The butyraldehyde product, heavy component impurities, and catalyst mixture discharged from the bottom of the stripping column 3 enter the catalyst separation tank 4 to separate the catalyst. The separated catalyst is transported from the second outlet at the bottom of the catalyst separation tank 4 to the catalyst regeneration tank 8 through the seventh pipeline 22. The catalyst is separated from the mixture by the cyclone separation zone composed of 3 groups of cyclones and the gravity sedimentation of the conical collection tank. The separated catalyst is transported from the second outlet at the bottom of the catalyst separation tank 4 to the catalyst regeneration tank through the seventh pipeline 22 for regeneration treatment to remove the heavy component impurities on the surface.

[0051] The remaining mixture is depressurized to 1.3 atm through the third pipeline 18 equipped with a two-stage pressure relief valve 12 and sent to the second evaporator 5. In the second evaporator 5, it is heated by 0.2 MPa steam, and the butyraldehyde is vaporized for subsequent purification and collection.

[0052] The vaporized butyraldehyde and the remaining catalyst particles enter the catalyst cooling tower 6 through the fourth pipeline 19. In the interception scraper area 601, the gas reacts with the scraper during the rising process to prevent the catalyst particles from continuing to rise with the airflow. The scraper effectively intercepts most of the catalyst particles, and the intercepted catalyst particles slide down to the spiral pipeline 602. When the catalyst is sliding and on the landslide 603, it can be cooled by cooling water to further reduce the deactivation rate of the catalyst particles. The cooled catalyst particles are sent to the catalyst regeneration tank 8 through the eighth pipeline 23.

[0053] The gaseous butyraldehyde, carrying a small amount of catalyst particles, is discharged through the discharge outlet at the top of the catalyst cooling tower 6 and enters the separation tower 7 through the fifth pipeline 20. Further separation of the gaseous butyraldehyde and the residual catalyst particles is carried out to purify the vaporized butyraldehyde. The pure butyraldehyde is discharged from the product extraction outlet at the top of the separation tower 7 and is condensed and liquefied by the second condenser 14 on the output pipeline 31 and sent to the butyraldehyde storage tank 9. In this step, the purity of the gaseous butyraldehyde is ensured, and at the same time, a small amount of catalyst particles that may be carried out by the airflow are recovered.

[0054] The catalyst particles separated in the separation column 7 are transported to the catalyst regeneration tank 8 through the sixth pipeline 21. The catalyst regeneration tank 8 processes the transported catalyst, and the processed catalyst particles are transported to the catalyst tank 10 for storage through the circulation pipeline 26. The heavy component impurities are discharged from the tank body. When butyraldehyde needs to undergo the next round of synthesis, it flows back to the slurry bed reactor 1 through the circulation pipeline 26.

[0055] Part of the liquid butyraldehyde in the butyraldehyde storage tank 9 will enter the washing liquid storage tank 28 through the reflux pipeline 27. When the washing liquid supply area 302 of the stripping column 3 needs it, it enters the washing liquid supply area 302 from the washing liquid storage tank 28 through the reflux pipeline 27 to remove the catalyst particles on the wire mesh area 301 and the packing area 303 to prevent blockage.

[0056] Example 3 The specific implementation method is the same as that of Example 1, except that a single layer of wire mesh and packing is used.

[0057] Comparative Example 1 The specific implementation manner is the same as that of Example 1, except that the mass transfer intensification unit is not used.

[0058] Comparative Example 2 The specific implementation manner is the same as that of Example 1, except that the evaporator is changed to be heated by 0.4 MPa steam, and the evaporator is changed to a co-current mode.

[0059] Comparative Example 3 The specific implementation manner is the same as that of Example 1, except that the catalyst regeneration tank is not used.

[0060] Comparative Example 4 The specific implementation manner is the same as that of Example 1, except that the catalyst cooling tower is not used.

[0061] Comparative Example 5 The specific implementation manner is the same as that of Example 1, except that the pressure relief valve is not used.

[0062] Comparative Example 6 The specific implementation manner is the same as that of Example 1, except that only the wire mesh area is used alone.

[0063] Experimental Example 1 The yields of butyraldehyde and the recovery rates of raw materials in Examples 1 - 3 and Comparative Examples 1 - 6 were measured, and the final results are as follows:

[0064] As can be seen from the above table, through Example 1 and Comparative Example 1, it can be seen that by using a mass transfer intensification unit in the present invention, hydrogen and carbon monoxide react in this unit, causing them to be broken into nanoscale bubbles in the slurry bed reactor for butyraldehyde synthesis, thereby increasing the phase boundary area of the butyraldehyde synthesis reaction system. The increase in the phase boundary area enables the operating pressure in the butyraldehyde synthesis reactor to be reduced, and at the same time promotes a more complete and thorough reaction of propylene, carbon monoxide, and hydrogen in the reaction tower. Compared with Comparative Example 1, through the application of the mass transfer intensification unit in the present invention, the gas-liquid mixture is evenly mixed, the reaction efficiency is high, the synthesis yield of butyraldehyde is effectively increased, and a high raw material recovery rate is maintained at the same time.

[0065] From Example 1 and Comparative Examples 2 and 5, it can be seen that in Comparative Example 2, the recovery rates of propylene (86.7%) and carbon monoxide and hydrogen (81.4%) are both lower than those in Example 1, and the catalyst circulation capacity (72.2%) decreases; in Comparative Example 5, due to the absence of a pressure relief valve, the sudden change in pressure causes turbulence in the slurry mixture, and the separation and regeneration effects of the catalyst are affected due to changes in evaporation conditions. The catalyst circulation capacity is also relatively low (70.2%). Therefore, in the present invention, the pressure is gradually released through primary pressure relief (12 → 4 atm) and secondary pressure relief (4 → 1.3 atm) to avoid catalyst fragmentation or gas escape caused by sudden pressure changes; and by combining with an evaporator, the pressure inside the evaporator is reduced, enabling it to use 0.2 MPa steam, with lower energy consumption, a significant reduction in the deactivation amount of the catalyst, a remarkable improvement in economic benefits, and a small pressure reduction amplitude for each stage.

[0066] For Example 1 and Comparative Examples 3 and 4, it can be seen that the catalyst circulation capacities of Comparative Examples 3 - 4 significantly decrease (72.5%, 71.3%). The impurities gradually accumulated by the catalyst during the reaction cannot be removed, resulting in a rapid decay of the catalyst activity. The catalyst cannot be cooled in a timely manner after the reaction and remains in a high-temperature environment for a long time, accelerating the deactivation rate of the catalyst and further reducing the catalyst's ability to be recycled. By using a spiral pipe cooling system, the sintering phenomenon of the catalyst at high temperatures is effectively inhibited, and the structure and activity of the catalyst are maintained. In the present invention, in the form of combining a catalyst cooling tower and a catalyst regeneration tank in the recovery module, the carbon, sulfides, and other impurities accumulated on the catalyst surface are effectively removed, thereby restoring its active sites and maintaining the high activity of the catalyst.

[0067] It can also be seen from Example 3 and Comparative Example 6 that the functions of the wire mesh and the packing in the stripping column are also very important. In Example 1, a multi-layer wire mesh (intercepting large particle impurities) and a high-efficiency packing (increasing gas-liquid contact) are used, and the separation efficiency is higher; the single-layer structure in Example 2 results in impurity penetration, aggravated catalyst surface contamination, and decreased circulation capacity; in Comparative Example 6, only a wire mesh is used. Under the same separation conditions, although it can play a separation role, compared with the case of using a wire mesh and a packing in combination, it cannot meet the requirements of high-quality products and high recovery rate of raw materials in the present invention.

[0068] Through the device of the present invention, not only the efficiency of the butyraldehyde synthesis reaction is significantly improved, the energy consumption is greatly reduced, but also the recovery rate of raw materials is effectively increased, and at the same time, the loss of the catalyst is reduced, fundamentally solving many problems existing in the prior art. It provides an efficient and sustainable solution for the industrial upgrading of butyraldehyde synthesis, and strongly promotes the green development and technological progress of the butyraldehyde production industry.

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A low-pressure recovery device for synthetic butyraldehyde, characterized in that: include: Slurry bed reactor, recovery module; A feed inlet is provided on one side of the slurry bed reactor, and a discharge port is provided on the upper side thereof, which is connected to the primary pressure relief valve at the starting point of the recovery module through a first pipeline. The first pipeline transports the slurry mixture through the primary pressure relief valve to the primary evaporator; The bottom outlet of the primary evaporator is connected to the feed port on one side of the stripping tower through a second pipeline, and the second pipeline is used to send the gas slurry mixture to the stripping tower for separation; The outlet of the stripping tower is connected to the feed port at the top of the secondary evaporator through a third pipeline provided with a secondary pressure relief valve, so as to transport the slurry mixture at the bottom of the stripping tower to the secondary evaporator for gasification of butyraldehyde; The bottom of the secondary evaporator is provided with a discharge port, and the discharge port is connected to the feed port of the side wall of the catalyst cooling tower through a fourth pipeline to cool the catalyst in the gasified butyraldehyde; The top discharge port of the catalyst cooling tower is connected to the feed port of the side wall of the separation tower through a fifth pipeline, so as to separate the catalyst in the butyraldehyde; the bottom discharge port of the catalyst cooling tower is connected to the catalyst regeneration tank through a sixth pipeline; The top of the separation tower is provided with a product outlet, and the bottom is provided with a discharge port, which is connected to the catalyst regeneration tank through a seventh pipeline to transport the catalyst in the separation tower to the catalyst regeneration tank for catalyst regeneration treatment; The bottom of the catalyst regeneration tank is provided with an outlet, and the bottom of the slurry bed reactor is provided with a circulation port. The outlet and the circulation port are connected through a circulation pipeline to reflux the catalyst at the bottom of the catalyst regeneration tank to the slurry bed reactor.

2. The synthetic butyraldehyde low-pressure recovery device according to claim 1, characterized in that: It also includes a catalyst separation tank, which is located between the stripping tower and the secondary evaporator; a cyclone separation zone composed of multiple groups of cyclones is provided in the middle of the catalyst separation tank, which uses centrifugal force to separate the catalyst and liquid in the slurry mixture; the bottom of the catalyst separation tank is configured as a conical collecting tank, and part of the catalyst is collected by gravity sedimentation; a second outlet is provided at the bottom of the conical collecting tank, and the second outlet is connected to the feed port of the catalyst regeneration tank through a seventh pipeline to transport the catalyst to the catalyst regeneration tank.

3. The low-pressure recovery device for synthetic butyraldehyde according to claim 1, characterized in that: The top of the catalyst regeneration tank is provided with a washing area with a spray layer, and an ultrasonic separator is embedded in the side wall of the tank body to cover the entire washing area to eliminate impurities on the catalyst surface. A centrifuge and a drying channel are also provided at the bottom of the tank body to separate the spray liquid and recycle the catalyst.

4. The low-pressure recovery device for synthetic butyraldehyde according to claim 1, characterized in that: The catalyst cooling tower is composed of a column and a box body, the inlet of the box body is arranged in the middle, and an intercepting scraper area is arranged on the upper part of the inlet, and a ring-shaped spiral pipe is arranged at the bottom of the intercepting scraper area; the catalyst cooling tower is provided with a water inlet and a water outlet; the spiral pipe passes through the column below and enters the box body, and a landslide is obliquely arranged in the box body, and the landslide outlet is connected to the catalyst regeneration tank through an eighth pipe to transport the cooled catalyst to the catalyst regeneration tank.

5. The low-pressure recovery device for synthetic butyraldehyde according to claim 1, characterized in that: The stripping tower is provided with a gas extraction port at the top and has a layered structure with a wire mesh area, a washing liquid supply area and a packing area arranged in sequence from top to bottom, so that the vaporized propylene and the raw material gas can be discharged and recovered from the gas extraction port, and the gas extraction port is connected to the first condenser through a pipeline.

6. The low-pressure recovery device for synthetic butyraldehyde according to claim 1, characterized in that: A mass transfer intensification unit is arranged at the bottom of the slurry bed reactor, and microbubbles are sprayed out by the mass transfer intensification unit. A gas outlet is arranged at the top for discharging gas raw materials not used in the reaction process. The gas outlet is connected with the inlet of the raw material recovery tank through a ninth pipeline to send the gas raw materials into the raw material recovery tank for storage.

7. The low-pressure recovery device for synthetic butyraldehyde according to claim 5, characterized in that: The product outlet is connected to the inlet of the butyraldehyde storage tank through an output pipeline, and a second condenser is provided on the output pipeline to deliver the condensed butyraldehyde to the butyraldehyde storage tank.

8. The low-pressure recovery device for synthetic butyraldehyde according to claim 7, characterized in that: The butyraldehyde storage tank is provided with a reflux port, which is connected to the port of the washing liquid supply area through a reflux pipeline to reflux part of the butyraldehyde to the washing liquid supply area; a plurality of spray layers are arranged in the washing liquid supply area along the side wall of the stripping tower, and the spray layer is composed of a washing liquid delivery pipeline and a plurality of evenly distributed spray heads; a washing liquid storage tank is arranged on the reflux pipeline to facilitate the continuous supply of washing liquid.

9. The low-pressure recovery device for synthetic butyraldehyde according to claim 1, characterized in that: The circulation pipeline is provided with a catalyst tank for circulating the catalyst in the catalyst regeneration tank back to the catalyst tank, and a feed port is provided on one side of the catalyst tank for replenishing the catalyst.

10. A synthetic recovery method used in the synthetic butyraldehyde low-pressure recovery device according to any one of claims 1 to 9, characterized in that: The following steps are involved: CO, H2, propylene and catalyst are introduced into the slurry bed reactor in sequence for reaction. After the reaction is complete, the catalyst is recovered through a recovery module to obtain a product.

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