Low-pressure recovery device for synthetic butyraldehyde

Abstract

The utility model 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 disclosed by the utility model, the butyraldehyde synthesis efficiency is improved, the high-purity separation of butyraldehyde and the cyclic utilization of raw materials are realized through multi-stage evaporation, steam stripping separation and catalyst cyclic regeneration.

Description

TECHNICAL FIELD

[0001] The utility model belongs to chemical engineering and process technology field, and concretely relates to a kind of synthetic butyraldehyde low-pressure recovery device. BACKGROUND

[0002] Butyraldehyde as important organic chemical raw material, plays an important role in numerous industrial production fields, with extensive application value.But there are many problems to be solved in traditional butyraldehyde synthesis process, in raw material recovery link, traditional process energy consumption is higher, which not only increases cost, also reduces efficiency, and current energy saving and emission reduction, improve resource utilization rate development concept is contrary.Meanwhile, in traditional process, on the one hand, catalyst recovery link needs to be realized by high-temperature distillation or solvent extraction, not only high energy consumption, and catalyst in repeated cycle due to carbon deposition, sintering and other reasons lead to activity rapid decay, even after catalyst deactivation, its catalytic performance is greatly reduced, leading to reaction rate reduction, product yield reduction, in order to ensure the normal operation of production needs frequent supplement or replacement, greatly increased production cost also limits the continuity and stability in production process.

[0003] Therefore, the utility model is proposed. UTILITY MODEL CONTENT

[0004] The first purpose of the utility model is to provide a kind of synthetic butyraldehyde low-pressure recovery device, the device is combined by slurry bed reactor and recovery module, realizes the improvement of butyraldehyde synthesis efficiency and the high-purity separation of butyraldehyde and the recycling of unreacted raw material, simultaneously reduces the deactivation rate of catalyst to make the recovery rate of catalyst higher, reduces the consumption of catalyst in use process, improves resource utilization rate, reduces energy consumption and cost.

[0005] In order to realize the above-mentioned purpose of the utility model, the following technical scheme is adopted:

[0006] The utility model provides a kind of synthetic butyraldehyde low-pressure recovery device, comprising: slurry bed reactor, recovery module;

[0007] The side of the slurry bed reactor is equipped with feed inlet, and the upper side is provided with discharge port and is connected with the starting point of recovery module through first pipeline and one-stage pressure relief valve, the first pipeline transports slurry mixture to one-stage evaporator after one-stage pressure relief valve;

[0008] The bottom outlet of the one-stage evaporator is connected with the feed inlet of one side of stripping column through second pipeline, and the second pipeline is used to send gas slurry mixture to the stripping column for separation;

[0009] The outlet of the stripping tower is connected with the feed inlet of the top of the secondary evaporator through a third pipeline provided with a two-stage 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;

[0010] The bottom of the secondary evaporator is provided with a discharge outlet, which is communicated with the feed inlet of the sidewall of the catalyst cooling tower through a fourth pipeline, so as to cool the catalyst in the gasified butyraldehyde;

[0011] The top discharge outlet of the catalyst cooling tower is communicated with the feed inlet of the sidewall of the separation tower through a fifth pipeline, so as to separate the catalyst in the butyraldehyde; the discharge outlet at the bottom of the catalyst cooling tower is connected with the catalyst regeneration tank through a sixth pipeline;

[0012] The top of the separation tower is provided with a product outlet, and the bottom is provided with a discharge outlet, which is connected with the catalyst regeneration tank through a seventh pipeline, so as to transport the catalyst in the separation tower to the catalyst regeneration tank for catalyst regeneration treatment;

[0013] The bottom of the catalyst regeneration tank is provided with a discharge outlet, and the bottom of the slurry bed reactor is provided with a return outlet, and the discharge outlet and the return outlet are connected through a circulation pipeline, so as to return the catalyst at the bottom of the catalyst regeneration tank to the slurry bed reactor.

[0014] In the synthetic butyraldehyde low-pressure recovery device, the slurry bed reactor is a reaction area of butyraldehyde synthesis, which generates a slurry mixture (product butyraldehyde, unreacted raw material propylene and catalyst), and the slurry mixture is then transported to a recovery module through a pipeline for subsequent treatment. The evaporator and the pressure relief valve are used on the recovery module, and multi-stage pressure reduction is realized, which is not only beneficial to gradually reducing the pressure in the device, but also further reduces the deactivation rate of the catalyst in the catalyst recovery process through cooperation with the catalyst cooling tower, effectively improving the recovery efficiency of the catalyst. In the traditional process, the pressure in the evaporator is 11-14 atm, and high-temperature steam of 140 DEG C is needed for countercurrent heat exchange, resulting in a large amount of heat concentration, producing 110 DEG C condensate water, and also causing the temperature of about 2 / 3 area of the evaporator to rise to above 120 DEG C. This high-temperature environment greatly accelerates the deactivation of the catalyst, significantly increasing the production cost. The synergistic effect of the multi-stage evaporator and the pressure relief valve not only realizes effective control of 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 utility model adopts parallel flow heat exchange to effectively control the temperature difference between the catalyst particles and the heat exchange pipe wall, avoiding local overheating, thereby reducing the deactivation rate of the catalyst in the recovery process. Compared with the high temperature of the traditional process, the utility model only needs 120 DEG C, 0.2 MPa water vapor heating in the evaporator; promotes the closed-loop use of synthetic raw materials, and fundamentally reduces the consumption cost of the catalyst. Figure 2

[0015] Preferably, it further comprises a catalyst separation tank, which is located between the stripping tower and the secondary evaporator; a cyclone separation zone composed of multiple cyclones is arranged 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 arranged into a conical collection groove to collect part of the catalyst by gravity settling; and the bottom of the conical collection groove is provided with a second outlet connected with the feed inlet of the catalyst regeneration tank through a seventh pipeline to transport the catalyst to the catalyst regeneration tank.

[0016] In the device, a catalyst separation tank is further arranged to effectively separate the catalyst and the liquid before the slurry mixture enters the secondary evaporator. The cyclone separation zone composed of 2-3 cyclones separates the catalyst and the liquid in the slurry mixture by centrifugal force, thereby improving the recovery rate of the catalyst. The bottom is arranged into a conical collection groove to facilitate the collection of the catalyst by gravity settling. The conical structure enables the catalyst to be more easily gathered at the bottom of the groove, facilitating subsequent transportation and regeneration treatment. This is the preliminary separation of the catalyst particles.

[0017] ​Preferably, the top of the catalyst regeneration tank is provided with a spray layer in the washing area, the sidewall of the tank body is embedded with ultrasonic separators covering the whole washing area, the impurities on the surface of the catalyst are removed, and a centrifuge and a drying channel are further arranged at the bottom of the tank body to separate the spray liquid and recycle the catalyst.

[0018] In the present scheme, the catalyst regeneration tank can efficiently regenerate the catalyst through the steps of washing, separation and drying, the regenerated catalyst is returned to the slurry bed reactor through the circulation pipeline, the recycling of the catalyst is realized, the production cost is reduced, and the generation of waste is reduced.

[0019] Preferably, the catalyst cooling tower is composed of a column and a box, the inlet of the box is arranged in the middle, an intercepting scraper area is arranged at the upper part of the inlet, an annular spiral 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 below penetrates the column into the box, a landslide is arranged in the box, and the outlet of the landslide is connected with the catalyst regeneration tank through an eighth pipeline to transport the cooled catalyst to the catalyst regeneration tank.

[0020] In the catalyst cooling tower in the present device, when the gaseous butyraldehyde carrying catalyst particles enters the column, the catalyst will rise with the airflow; when this airflow passes through the interception scraper area, most of the catalyst particles are effectively intercepted due to the blocking effect of the scraper, and these intercepted catalyst particles slowly slide down along the inclined surface at the bottom of the area under the action of gravity, and finally enter the annular spiral spiral pipe arranged below; in the spiral pipe, the catalyst particles flow down along the spiral path in an orderly and slow manner, which not only ensures that the catalyst particles can be fully dispersed, but also greatly prolongs the contact time with the cooling water. During the sliding process of the catalyst particles in the spiral pipe, cooling water is introduced through the water inlet of the cooling tower to exchange heat with the catalyst particles, effectively reducing the temperature of the catalyst, thereby avoiding the problem of sintering deactivation caused by high-temperature retention. With the continuous sliding of the catalyst particles in the spiral pipe, they will eventually reach the end of the spiral pipe and fall onto the inclined landslide in the box. In order to ensure that too many catalyst particles do not accumulate on the landslide, the landslide has a certain inclination angle, and a vibration motor is arranged on the landslide to periodically vibrate to further promote the sliding and dispersion of the catalyst particles. The design of the landslide enables the catalyst particles to smoothly slide 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 prolongs the service life of the catalyst particles but also improves the recovery rate, reduces the cost expenditure caused by frequent replacement of catalysts, and improves the efficiency and sustainability of the entire production process. The gaseous butyraldehyde with the remaining catalyst particles is discharged from the discharge port at the top of the catalyst cooling tower and enters the separation tower through the fifth pipeline, where the gaseous butyraldehyde is further separated from the residual catalyst particles. This process ensures the purity of gaseous butyraldehyde while recovering trace amounts of catalyst particles that may be carried away by the airflow.

[0021] Preferably, the top of the stripping tower is provided with a gas outlet and is a layered structure from top to bottom, which is provided with a wire mesh area, a washing liquid supply area and a filler area in turn, so that the gasified propylene and the raw gas are discharged and recovered from the gas outlet, and the gas outlet is connected with the first condenser through a pipeline.

[0022] In the device, most of the gasified propylene, a small amount of hydrogen and carbon monoxide bubbles and the slurry mixture containing the catalyst enter the stripping tower to achieve effective separation of the gas and the slurry mixture. Since a certain amount of bubbles will be generated in the process of the synthetic device, these bubbles will not only drive the catalyst particles to rise together, but also be not conducive to the separation and recovery of raw materials. Therefore, the utility model is provided with a silk screen area and a packing area in the stripping tower to achieve effective separation of the catalyst particles and the gas. The silk screen area is specially configured as a multi-layer structure, and the design of the multi-layer silk screen can not only effectively intercept and break the rising bubbles to reduce the driving effect of the catalyst particles, but also promote the full contact and mass transfer of the gas-liquid two phases through the fine mesh structure, thereby improving the separation efficiency. At the same time, the multi-layer silk screen can also avoid the plugging problem caused by the agglomeration of the catalyst particles into larger particles on the surface of the single-layer silk screen. In order to further optimize the separation effect and the recovery of the catalyst, the packing area is arranged below the silk screen area, and a certain distance is maintained between the packing and the silk screen. The packing plays an important role in intercepting the solid catalyst particles and preventing them from rising with the foam and plugging the silk screen due to its high specific surface area and excellent mass transfer performance. 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 silk screen 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.

[0023] Preferably, the bottom of the slurry bed reactor is provided with a mass transfer intensifier unit, the micro-bubbles sprayed by the mass transfer intensifier unit, and a gas outlet is arranged at the top of the slurry bed reactor for discharging the unused gas raw materials in the reaction process, and the gas outlet is communicated with 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.

[0024] In the slurry bed reactor in the device, a mass transfer intensifier unit is used to optimize the synthesis process of butyraldehyde. The unit significantly increases the contact area of the gas-liquid two phases by introducing carbon monoxide and hydrogen and utilizing its internal structure design. At the same time, a nano-particle catalyst is used, which further improves the reaction efficiency due to its high specific surface area and unique electronic structure. When hydrogen and carbon monoxide pass through the intensifier unit, they are converted into micron-sized bubbles and sent into the butyraldehyde synthesis reactor, which greatly increases the interfacial area of the reaction system. The increase in the interfacial area enables the reaction of propylene, carbon monoxide and hydrogen in the reaction tower to be more complete at a lower operating pressure, thereby significantly improving 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, which can be directly recycled for use in the next round of butyraldehyde synthesis after being treated by flash technology, thereby realizing the maximum utilization of resources and effective reduction of costs.

[0025] Preferably, the product outlet is connected to the inlet of the butyraldehyde storage tank through an outlet pipeline, and a second condenser is arranged on the outlet pipeline to send the condensed butyraldehyde to the butyraldehyde storage tank.

[0026] In the device, the butyraldehyde vapor flowing out from the product outlet after separation is fully condensed by the second condenser, so that the pure butyraldehyde flows into the butyraldehyde storage tank in the form of liquid.

[0027] Preferably, the butyraldehyde storage tank is provided with a reflux port, 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; a plurality of spray layers are arranged along the side wall of the stripping tower in the washing liquid supply area, and each spray layer is composed of a washing liquid conveying pipeline and a plurality of uniformly distributed spray heads; and a washing liquid storage tank is arranged on the reflux pipeline to facilitate continuous supply of washing liquid.

[0028] In the device, part of the butyraldehyde in the butyraldehyde storage tank is returned as part of the washing liquid, 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 is returned to the washing liquid supply area through the reflux port and the reflux pipeline, the multi-layer spray layer further ensures that the washing liquid can be uniformly and fully sprayed in the stripping tower, further enhancing the separation and purification effect of the stripping tower. The washing liquid can be sprayed to cover the packing area and the wire mesh area, forming a liquid film. This liquid film not only intercepts a small amount of catalyst particles and impurities rising with the gas bubbles, but also removes the catalyst particles accumulated above the wire mesh and packing for washing, so that they can be lowered to the bottom of the gas washing tower with the butyraldehyde liquid, and then recycled along the process.

[0029] Preferably, a catalyst tank is arranged on the circulation pipeline to return the catalyst in the catalyst regeneration tank to the catalyst tank, and a feeding port is arranged on one side of the catalyst tank to supplement the catalyst.

[0030] Catalysts play a crucial role in butyraldehyde synthesis reactions, as they can accelerate reaction rates and improve product yield and purity. However, over time, the activity of some catalysts may gradually decrease or even deactivate. Therefore, regular replacement or regeneration of catalysts is essential to maintain production efficiency. The regenerated catalyst is returned to the catalyst tank through the circulation pipeline and is used again for catalytic reactions. This recycling method not only reduces catalyst waste but also reduces production costs. 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 feeding port to ensure that there is always enough catalyst in the reaction device.

[0031] The mass transfer intensifier unit of the utility model belongs to prior art, and the skilled in the art can understand that the unit exists in different types such as pneumatic type, hydraulic type and gas-liquid linkage type, but the selection among these types is mainly determined according to specific working conditions. As for the connecting mode of the unit with the slurry bed reactor and other equipment, the connecting structure and connecting position are covered, and need to be determined according to the structure of the slurry bed reactor, and are not limited specifically herein.

[0032] In the utility model, flow control valves, pressure monitoring devices and the like are arranged on the pipeline and the pipeline, so as to ensure the reasonable flow of materials and the stable control of process parameters.

[0033] Compared with the prior art, the utility model has the beneficial effects that:

[0034] (1) The utility model realizes the efficient utilization of catalyst and the maximum recovery of resources through the combination of the slurry bed reactor and the recovery module. The slurry bed reactor provides ideal conditions for catalytic reaction with its good mixing effect and high mass and heat transfer rate, and ensures the efficient reaction. At the same time, the introduction of the recovery module enables the unreacted raw materials, by-products and catalyst generated in the reaction process to be effectively separated and recovered, improves the recovery rate of raw materials, and avoids the waste of resources and the pollution of the environment.

[0035] (2) The utility model forms the effect of multi-stage pressure relief through the combination of the evaporator and the pressure relief valve, reduces the boiling point of butyraldehyde, and butyraldehyde can be effectively gasified at a relatively low temperature; the multi-stage step-by-step release of pressure will not cause a large amount of catalyst deactivation due to high temperature and sharp pressure change in the gasification process, and is supplemented by the catalyst cooling tower, which cools the catalyst carrying heat in time after butyraldehyde gasification, effectively reduces the temperature of the catalyst, reduces the reduction of catalyst activity and structural damage caused by temperature, and further improves the recovery rate of the catalyst.

[0036] (3) The recovery module in the utility model is designed with a multi-stage recovery process, so that each raw material component can be carefully separated and purified, and ensures that butyraldehyde generated in the synthesis process and all input raw materials can be recycled and reused to the maximum extent. BRIEF DESCRIPTION OF DRAWINGS

[0037] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are for purposes of illustration only and are not considered a limitation of the present utility model. Moreover, like reference numerals are used to designate identical parts throughout the specification and drawings. In the drawings:

[0038] Figure 1The utility model discloses a kind of synthetic butyral low-pressure recovery device's structural diagram;

[0039] Figure 2 It is the contrastive drawing of evaporator (B) of the utility model with traditional process evaporator (A).

[0040] Reference Signs:

[0041] 1-slurry bed reactor, 2-primary evaporator, 3-stripper column, 4-catalyst separation tank, 5-secondary evaporator, 6-catalyst cooling tower, 7-separation column, 8-catalyst regeneration tank, 9-butyl aldehyde 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-backflow pipeline, 28-washing liquid storage tank, 31-output pipeline, 101-mass transfer intensifier unit, 102-synthetic gas feed pipe, 103-propylene feed pipe, 301-wire mesh zone, 302-washing liquid supply zone, 303-packing zone, 601-intercepting scraper zone, 602-spiral pipeline, 603-landslide. DETAILED DESCRIPTION

[0042] The technical scheme of the utility model will be described clearly and completely in connection with drawings and specific embodiments below, but those skilled in the art will understand that the following described embodiments are part of the embodiments of the utility model, not all the embodiments, and are only used to illustrate the utility model, and should not be regarded as limiting the scope of the utility model. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor belong to the scope of protection of the utility model. Not specified in the embodiment, according to conventional condition or manufacturer's suggested condition. The reagents or instruments used are not marked by manufacturer, which are conventional products that can be purchased in the market.

[0043] In the description of the utility model, it needs to be explained that the orientation or position relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like is based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the utility model and simplifying the description, and therefore cannot be understood as limiting the device or element indicated or implied to have a particular orientation, to be constructed and operated in a particular orientation, so it cannot be understood as limiting the utility model. In addition, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0044] In the description of the utility model, it needs to explain, unless there is definite provision and limitation, the term "installation", "link", "connection" should do broad sense understanding, for example, can be fixed connection, also can be detachable connection, or integrally connected;Can be mechanical connection, also can be electrical connection;Can be directly connected, also can be indirectly connected through intermediate medium, can be two elements inside the communication。For ordinary skilled person in the art, the above-mentioned terms can be understood in the specific meaning in the utility model according to specific circumstances.

[0045] The technical scheme of the utility model provides a kind of synthetic butyraldehyde low-pressure recovery device, comprising: slurry bed reactor 1 and recovery module.In traditional butyraldehyde synthesis system, the pressure in butyraldehyde synthesis reactor is higher, usually maintained at 18-19atm, and the contact area between gas-liquid two phases is limited.This greatly limits the full contact between reactants, and further affects the reaction.In order to ensure that the reaction can continue to advance, the temperature of the reactor often needs to be increased by 10-15 ℃.However, temperature rise will adversely affect the recovery effect of catalyst, but not improving temperature will lead to the reaction cannot be completely carried out, and the yield of product will also be reduced.

[0046] This invention adds a mass transfer enhancement component 101 to the slurry bed reactor 1. During the synthesis process, this component converts 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 this device to achieve a more efficient reaction under lower pressure conditions (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 catalyst particles improved, but the energy consumption required for catalyst particle recovery is also greatly reduced, achieving low-energy recovery while significantly improving the recovery rate of catalyst particles. After the reaction, the material first passes through a primary pressure relief valve 11 in the recovery module, reducing the pressure to 4 atm. In the primary evaporator 2, as the pressure decreases, the temperature required for evaporation also decreases accordingly. Then, the material is further depressurized through a secondary pressure relief valve 12, with the pressure dropping to 1.3 atm, which further reduces the evaporation temperature in the secondary evaporator 12. Compared with traditional evaporators, the evaporator in this invention operates at a lower temperature. Under such pressure, butyraldehyde has a low boiling point and only requires heating with 0.2 MPa steam at 120°C to evaporate, avoiding the problem of significant catalyst deactivation due to high temperatures. The catalyst cooling tower 6 connected after the secondary evaporator further cools the catalyst after evaporation, further reducing the catalyst deactivation rate and improving catalyst recovery. Therefore, compared with traditional technologies, this invention, through staged pressure reduction and the addition of a catalyst cooling tower, ensures that the temperature throughout the device remains relatively constant, reducing catalyst deactivation and increasing the yield of raw materials and products.

[0047] To more clearly illustrate the technical solution of this utility model, the following description is provided in the form of specific embodiments.

[0048] Example 1

[0049] See Figure 1 As shown, this utility model is a low-pressure recovery device for synthetic butyraldehyde. The synthetic butyraldehyde recovery process 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 the carbon monoxide and hydrogen into micron-sized bubbles and reacts them with propylene. The pressure of the slurry bed reactor 1 is controlled at 12 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 pipe 24 for flash evaporation treatment and storage for the next round of use.

[0050] The remaining product butyraldehyde, unreacted raw material propylene and catalyst are in slurry state and flow into the recovery module; first, the slurry mixture is depressurized to 4 atm by the first pressure relief valve 11 on the first pipeline 16 and then enters the first evaporator 2, where most of the propylene is vaporized.

[0051] The vaporized propylene and the remaining slurry mixture enter the stripping through the second pipeline 17. In the stripping tower 3, most of the vaporized propylene and a small amount of hydrogen and carbon monoxide bubbles are discharged through the gas outlet at the top by the wire mesh 301 and the packing zone 303, then pass through the tenth pipeline 25 and are condensed by the first condenser 13 on the pipeline, and finally flow into the raw material recovery tank 15 for storage, facilitating the use in the next round of synthesis.

[0052] The butyraldehyde product, heavy component impurities and catalyst mixture discharged from the bottom of the stripping tower 3 enter the catalyst separation tank 4 to separate the catalyst. The separated catalyst particles are 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 three cyclones and the gravity settling action 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.

[0053] The remaining mixture is depressurized to 1.3 atm by the third pipeline 18 provided with the second pressure relief valve 12 and sent to the second evaporator 5. In the second evaporator 5, the butyraldehyde is vaporized by heating with 0.2 MPa steam for subsequent purification and collection.

[0054] The vaporized butyraldehyde and the remaining catalyst particles enter the catalyst cooling tower 6 through the fourth pipeline 19. When the gas reacts with the scraper in the interception and scraping zone 601 during the upward process, the catalyst particles are prevented from continuing to rise with the gas flow. The scraper effectively intercepts most of the catalyst particles. The intercepted catalyst particles slide downward to the spiral pipeline 602. The catalyst is cooled by cooling water during the sliding process and when it is on the slide 603, further reducing the deactivation rate of the catalyst particles. The cooled catalyst particles are sent to the catalyst regeneration tank 8 through the eighth pipeline 23.

[0055] The gaseous butyraldehyde, carrying a small amount of catalyst particles, is discharged through the outlet at the top of the catalyst cooling tower 6 and enters the separation tower 7 through the fifth pipe 20. There, the gaseous butyraldehyde is further separated from the remaining catalyst particles, purifying the gasified butyraldehyde. The purified butyraldehyde is discharged from the product outlet at the top of the separation tower 7 and condensed into liquefaction via the production pipe 31 and the second condenser 14 on the pipe, before being sent to the butyraldehyde storage tank 9. This step ensures the purity of the gaseous butyraldehyde while recovering any small amount of catalyst particles that might have been carried away by the gas flow.

[0056] The catalyst particles separated in separation tower 7 are transported to catalyst regeneration tank 8 through sixth pipeline 21. Catalyst regeneration tank 8 processes the incoming catalyst, and the processed catalyst particles are transported to catalyst tank 10 for storage through circulation pipeline 26. Heavy component impurities are discharged from the tank. When butyraldehyde needs to be synthesized in the next round, it is returned to slurry bed reactor 1 through circulation pipeline 26.

[0057] Some of the liquid butyraldehyde in the butyraldehyde storage tank 9 will enter the washing liquid storage tank 28 through the return pipe 27. When the washing liquid supply area 302 of the stripping tower 3 needs it, it will enter the washing liquid supply area 302 from the washing liquid storage tank 28 through the return pipe 27 to remove the catalyst particles on the wire mesh area 301 and the packing area 303 and prevent blockage.

[0058] Example 2

[0059] This utility model is a low-pressure recovery device for synthetic 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 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 the carbon monoxide and hydrogen into micron-sized bubbles and reacts them 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 pipe 24 for flash evaporation treatment and storage for the next round of use.

[0060] The remaining product, butyraldehyde, unreacted raw material propylene, and catalyst flow out in a slurry state into the recovery module. The slurry mixture is first 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, where most of the propylene is vaporized.

[0061] The gasified propylene and the remaining slurry mixture are passed through the second conduit 17 into the stripping column, where the gasified propylene and a small amount of hydrogen and carbon monoxide bubbles are removed through the top gas outlet by the wire mesh 301 and the packing zone 303, passed through the tenth conduit 25 and condensed by the first condenser 13 on the conduit, and then flowed into the raw material recovery tank 15 for storage and use in the next round of synthesis.

[0062] The butyraldehyde product, heavy component impurities and catalyst mixture discharged from the bottom of the stripping column 3 are passed into the catalyst separation tank 4 to separate the catalyst, and the separated catalyst particles are transported from the second outlet at the bottom of the catalyst separation tank 4 to the catalyst regeneration tank 8 through the seventh conduit 22. The catalyst is separated from the mixture by the cyclone separation zone composed of three groups of cyclones and the gravity settling action 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 conduit 22 for regeneration treatment to remove the heavy component impurities on the surface.

[0063] The remaining mixture is depressurized to 1.3 atm by the third conduit 18 provided with a two-stage pressure relief valve 12 and sent to the two-stage evaporator 5, where the butyraldehyde is gasified by heating with 0.2 MPa steam for subsequent purification and collection.

[0064] The gasified butyraldehyde and the remaining catalyst particles are passed through the fourth conduit 19 into the catalyst cooling tower 6. When the gas passes through the intercepting scraper zone 601, the gas reacts with the scraper during the upward movement to prevent the catalyst particles from continuing to rise with the gas flow. The scraper effectively intercepts most of the catalyst particles, and the intercepted catalyst particles slide downward to the spiral conduit 602. The catalyst is cooled by the cooling water during the sliding process and when it is on the slide 603, further reducing the deactivation rate of the catalyst particles. The cooled catalyst particles are sent to the catalyst regeneration tank 8 through the eighth conduit 23.

[0065] The gaseous butyraldehyde with a small amount of catalyst particles is discharged through the discharge port at the top of the catalyst cooling tower 6 and passed through the fifth conduit 20 into the separation column 7 to further separate the gaseous butyraldehyde from the residual catalyst particles. The gasified butyraldehyde is purified, and the pure butyraldehyde is discharged from the product outlet at the top of the separation column 7, passed through the output conduit 31 and the second condenser 14 on the conduit to condense and liquefy the gasified butyraldehyde and sent to the butyraldehyde storage tank 9. In this step, the purity of the gaseous butyraldehyde is ensured, and a small amount of catalyst particles that may be carried away with the gas flow is recovered.

[0066] 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 through the circulation pipeline 26 for storage, and the heavy component impurities are discharged from the tank. When the butyraldehyde needs to be synthesized for the next round, it is returned to the slurry bed reactor 1 through the circulation pipeline 26.

[0067] Part of the liquid butyraldehyde in the butyraldehyde storage tank 9 enters the scrubbing liquid storage tank 28 through the reflux pipeline 27, and when the scrubbing liquid supply area 302 of the stripping tower 3 needs it, it enters the scrubbing liquid supply area 302 from the scrubbing liquid storage tank 28 through the reflux pipeline 27, and removes the catalyst particles on the wire mesh area 301 and the filler area 303, preventing clogging.

[0068] Example 3

[0069] The specific implementation method is consistent with that of Example 1, except that a single layer of wire mesh and filler is used.

[0070] Comparative Example 1

[0071] The specific implementation method is consistent with that of Example 1, except that the mass transfer enhancement unit is not used.

[0072] Comparative Example 2

[0073] The specific implementation method is consistent with that of Example 1, except that the evaporator is changed to use 0.4 MPa steam heating, and the evaporator is changed to a parallel flow mode.

[0074] Comparative Example 3

[0075] The specific implementation method is consistent with that of Example 1, except that the catalyst regeneration tank is not used.

[0076] Comparative Example 4

[0077] The specific implementation method is consistent with that of Example 1, except that the catalyst cooling tower is not used.

[0078] Comparative Example 5

[0079] The specific implementation method is consistent with that of Example 1, except that the pressure relief valve is not used.

[0080] Comparative Example 6

[0081] The specific implementation method is consistent with that of Example 1, except that only the wire mesh area is used.

[0082] Experimental Example 1

[0083] The yield of butyraldehyde and the recovery rate of raw materials in Examples 1-3 and Comparative Examples 1-6 were measured, and the final results are as follows:

[0084]

[0085] From the above table, it can be seen from Example 1 and Comparative Example 1 that, by adopting the mass transfer intensifier unit, the hydrogen and the carbon monoxide are reacted in the unit, the slurry bed reactor in the butyral synthesis is broken into nanoscale bubbles, thereby increasing the phase boundary area of the butyral synthesis reaction system. The increase of the phase boundary area can reduce the operating pressure in the butyral synthesis reactor, and promote the more complete and thorough reaction of the propylene, the carbon monoxide and the hydrogen in the reaction tower. Compared with Comparative Example 1, by adopting the mass transfer intensifier unit, the gas-liquid mixture is uniform, the reaction efficiency is high, the synthesis yield of the butyral is effectively improved, and a high raw material recovery rate is maintained.

[0086] From Example 1 and Comparative Examples 2 and 5, it can be seen that, in Comparative Example 2, the propylene recovery rate (86.7%), the carbon monoxide and hydrogen recovery rate (81.4%) are lower than those of Example 1, and the catalyst circulation capacity (72.2%) is reduced; in Comparative Example 5, because there is no pressure relief valve, the pressure mutation causes the turbulent flow of the slurry mixture, and the change of the evaporation condition affects the separation and regeneration effect of the catalyst. The catalyst circulation capacity is also low (70.2%). Therefore, by gradually releasing the pressure through the first pressure relief (12→4 atm) and the second pressure relief (4→1.3 atm), the sudden change of the pressure is avoided to cause the catalyst crushing or the gas escape; and by being combined with the evaporator, the pressure inside the evaporator is reduced, so that 0.2 MPa steam can be used, the energy consumption is lower, the catalyst deactivation amount is greatly reduced, the economic benefit is significantly improved, and the pressure reduction range of each stage is small.

[0087] From Example 1 and Comparative Examples 3 and 4, it can be seen that, the catalyst circulation capacity of Comparative Examples 3-4 is obviously reduced (72.5%, 71.3%), the impurities accumulated on the catalyst in the reaction process cannot be removed, the catalyst activity is rapidly attenuated, the catalyst cannot be cooled in time after the reaction, and is placed in a high temperature environment for a long time, so that the catalyst deactivation rate is accelerated, and the catalyst circulation use capacity is further reduced. By adopting the spiral pipeline cooling system, the sintering phenomenon of the catalyst at high temperature is effectively inhibited, and the structure and activity of the catalyst are maintained. By combining the catalyst cooling tower and the catalyst regeneration tank in the recovery module, the impurities such as carbon and sulfide accumulated on the catalyst are effectively removed, so that the active sites are restored, and the high activity of the catalyst is maintained.

[0088] It can also be seen from Example 3 and Comparative Example 6 that the action of the wire mesh and the filler in the stripping tower is also very important. Example 1 uses multiple layers of wire mesh (to intercept large-particle impurities) and high-efficiency fillers (to increase gas-liquid contact), so the separation efficiency is higher; the single-layer structure of Example 2 leads to impurity penetration and exacerbation of catalyst surface contamination, so the recycling capacity is reduced; Comparative Example 6 only uses wire mesh, and under the same separation conditions, although it can play a role in separation, it is unable to achieve the high-quality product and high raw material recovery rate of the present application compared with the case where the wire mesh and the filler are used in combination.

[0089] The device of the present application not only significantly improves the efficiency of butyral synthesis reaction, greatly reduces energy consumption, but also effectively improves the recovery rate of raw materials, while reducing the loss of catalyst, fundamentally solving many problems existing in the prior art. It provides an efficient and sustainable solution for the industrialization of butyral synthesis, and effectively promotes the green development and technological progress of the butyral production industry.

[0090] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for part or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solution to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A low-pressure recovery device for synthetic butyraldehyde, characterized in that, include: Slurry bed reactor, recovery module; The slurry bed reactor has an inlet on one side and an outlet on the upper side. The inlet is connected to the first-stage pressure relief valve at the starting point of the recovery module via a first pipe. The first pipe transports the slurry mixture to the first-stage evaporator after passing through the first-stage pressure relief valve. The bottom outlet of the first-stage evaporator is connected to the feed inlet on one side of the stripping tower via a second pipe, which 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 inlet at the top of the secondary evaporator via a third pipe equipped 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 the vaporization of butyraldehyde. The bottom of the secondary evaporator is provided with a discharge port, which is connected to the inlet of the catalyst cooling tower side wall through a fourth pipe to cool the catalyst in the gasified butyraldehyde. The top outlet of the catalyst cooling tower is connected to the inlet of the side wall of the separation tower through a fifth pipe for separating the catalyst in butyraldehyde; the bottom outlet of the catalyst cooling tower is connected to the catalyst regeneration tank through a sixth pipe. The top of the separation tower is provided with a product outlet and the bottom with a discharge outlet. It 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. The catalyst regeneration tank is provided with an outlet at the bottom, and the slurry bed reactor is provided with a circulation port at the bottom. The outlet and the circulation port are connected by a circulation pipeline to return the catalyst at the bottom of the catalyst regeneration tank to the slurry bed reactor.

2. The low-pressure recovery device for synthetic butyraldehyde according to claim 1, characterized in that, It also includes a catalyst separator, which is located between the stripping tower and the secondary evaporator; the catalyst separator has a cyclone separation zone composed of multiple sets of hydrocyclones in the middle, which uses centrifugal force to separate the catalyst and liquid in the slurry mixture; the bottom of the catalyst separator is set into a conical collection tank, which collects part of the catalyst by gravity settling; the bottom of the conical collection tank is provided with a second outlet, which is connected to the inlet of the catalyst regeneration tank through a seventh pipe 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 catalyst regeneration tank is equipped with a washing zone with a spray layer at the top, and an ultrasonic separator is embedded in the side wall of the tank to cover the entire washing zone, eliminating impurities on the catalyst surface. At the bottom of the tank, a centrifuge and a drying channel are also provided to separate the spray liquid and enable the catalyst to be recycled.

4. The low-pressure recovery device for synthetic butyraldehyde according to claim 1, characterized in that, The catalyst cooling tower consists of a column and a box. The inlet of the box is located in the middle, and an intercepting scraper area is provided above the inlet. A spiral pipe in the shape of an annular spiral is provided 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 and enters the box. An inclined slope is provided inside the box. The outlet of the slope 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 has a gas outlet at the top and a layered structure consisting of a wire mesh area, a washing liquid supply area, and a packing area arranged sequentially from top to bottom. This allows the vaporized propylene and raw material gas to be discharged and recovered from the gas outlet, which is connected to the first condenser via a pipeline.

6. The low-pressure recovery device for synthetic butyraldehyde according to claim 1, characterized in that, The slurry bed reactor is equipped with a mass transfer enhancement unit at the bottom. The microbubbles ejected by the mass transfer enhancement unit have a gas outlet at the top for discharging unused gaseous raw materials during the reaction. The gas outlet is connected to the inlet of the raw material recovery tank through a ninth pipe to send the gaseous 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 via an output pipe. A second condenser is installed on the output pipe to send 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 equipped with a reflux port, which is connected to the port of the washing liquid supply area via a reflux pipeline to return a portion of the butyraldehyde to the washing liquid supply area. The washing liquid supply area is provided with multiple spray layers along the side wall of the stripping tower. The spray layers consist of washing liquid conveying pipes and multiple evenly distributed spray heads. The reflux pipeline is equipped with a washing liquid storage tank to facilitate the continuous supply of washing liquid.

9. The low-pressure recovery device for synthetic butyraldehyde according to claim 1, characterized in that, A catalyst tank is provided on the circulation pipeline to circulate the catalyst in the catalyst regeneration tank back to the catalyst tank. An inlet is provided on one side of the catalyst tank to replenish the catalyst.

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