Low-pressure recovery device for synthesizing butyraldehyde, and synthesis and recovery method therefor

Abstract

Provided in the present invention is a low-pressure recovery device for synthesizing butyraldehyde, the device comprising a slurry bed reactor and a recovery module. A discharge port of the slurry bed reactor is connected to a first-stage evaporator by means of a first-stage pressure relief valve, and a gas-slurry mixture is outputted from the bottom of the first-stage evaporator to a stripping tower for separation. A material at the bottom of the stripping tower enters a second-stage evaporator via a second-stage pressure relief valve for butyraldehyde vaporization, and a vaporized product is conveyed to a catalyst cooling tower for cooling, and then enters a separation tower for catalyst separation. A catalyst at the bottom of the separation tower and a catalyst at the bottom of the cooling tower are both conveyed to a regeneration tank for regeneration, and a regenerated catalyst returns to the slurry bed reactor by means of a circulation pipe. By means of multi-stage evaporation, stripping separation and catalyst recycling and regeneration, the device achieves an improvement in the synthesis efficiency of butyraldehyde, and achieves high-purity separation of butyraldehyde and the recycling of raw materials.

Description

A low-pressure recovery device for synthetic butyraldehyde and its synthesis and recovery method Technical Field

[0001] This invention belongs to the field of chemical engineering and technology, and specifically relates to a low-pressure recovery device for synthesizing butyraldehyde and its synthesis method. Background Technology

[0002] Butyraldehyde, as an important organic chemical raw material, plays a vital role in numerous industrial production fields and has broad application value. However, the traditional butyraldehyde synthesis process faces many problems that urgently need to be solved. In the raw material recovery stage, the traditional process has high energy consumption, which not only increases costs but also reduces efficiency, contradicting the current development concept of energy conservation, emission reduction, and improved resource utilization. Furthermore, in the traditional process, catalyst recovery requires high-temperature distillation or solvent extraction, which is not only energy-intensive but also leads to rapid catalyst activity decay due to carbon buildup and sintering during repeated cycles. In some cases, catalyst deactivation results in a significant decrease in catalytic performance, leading to reduced reaction rates and product yields. Frequent replenishment or replacement is necessary to ensure normal production operation, significantly increasing production costs and limiting the continuity and stability of the production process. On the other hand, the separation efficiency of unreacted syngas feedstock (CO and H2) and light component byproducts is low. The raw materials in the traditional flash distillation process are not effectively recovered, resulting in resource waste and increased burden on tail gas treatment.

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

[0004] The primary objective of this invention is to provide a low-pressure recovery device for synthesized butyraldehyde. This device combines a slurry bed reactor and a recovery module to improve the synthesis efficiency of butyraldehyde, achieve high-purity separation of butyraldehyde, and recycle unreacted raw materials. At the same time, it reduces the deactivation rate of the catalyst, resulting in a higher catalyst recovery rate, reducing catalyst consumption during use, improving resource utilization, and reducing energy consumption and costs.

[0005] The second objective of this invention is to provide a synthesis and recovery method using a low-pressure recovery device for synthesized butyraldehyde. This method uses the aforementioned device to synthesize butyraldehyde and perform low-pressure recovery, which can improve the product yield and the recovery of raw materials.

[0006] To achieve the above-mentioned objectives of this invention, the following technical solution is adopted: This invention provides a low-pressure recovery device for synthesized butyraldehyde, comprising: a slurry bed reactor and a recovery module; the slurry bed reactor has an inlet on one side and an outlet on the upper side, which is connected to a first-stage pressure relief valve at the starting point of the recovery module via a first pipe, the first pipe conveying the slurry mixture through the first-stage pressure relief valve to a first-stage evaporator; the bottom outlet of the first-stage evaporator is connected to an inlet on one side of a stripping tower via a second pipe, the second pipe being used to send the gas-slurry mixture to the stripping tower for separation; the outlet of the stripping tower is connected to the inlet at the top of the second-stage evaporator via a third pipe equipped with a second-stage pressure relief valve, so as to convey the slurry mixture at the bottom of the stripping tower to the second-stage evaporator for butyraldehyde gasification; the bottom of the second-stage evaporator has an outlet, which is connected to the inlet on the side wall of a catalyst cooling tower via a fourth pipe, so as 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 via a fifth pipe for separating the catalyst in butyraldehyde; the bottom outlet of the catalyst cooling tower is connected to the catalyst regeneration tank via a sixth pipe; the top of the separation tower is provided with a product outlet, and the bottom is provided with an outlet, which is connected to the catalyst regeneration tank via a seventh pipe 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 via 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 butyraldehyde synthesis of this invention, the slurry bed reactor is the reaction zone for butyraldehyde synthesis, generating a slurry mixture (butyraldehyde product, unreacted propylene feedstock, and catalyst). This slurry mixture is then transported through pipelines to the recovery module for further processing. In the recovery module, an evaporator and a pressure relief valve are cleverly combined to achieve multi-stage pressure reduction. This not only facilitates a gradual reduction of the pressure within the device but also, in conjunction with the catalyst cooling tower, further reduces the deactivation rate of the catalyst during the recovery process, effectively improving the catalyst recovery efficiency. In conventional processes, the pressure inside the evaporator is 11-14 atm, requiring countercurrent heat exchange with high-temperature steam at 140°C. This results in a large concentration of heat, producing condensate at 110°C, and causing the temperature in approximately two-thirds of the evaporator area to rise above 120°C. This high-temperature environment significantly accelerates catalyst deactivation and substantially increases production costs. The synergistic effect of the multi-stage evaporator and pressure relief valve in this invention not only achieves effective pressure control but also further improves the separation efficiency of catalyst and product, reducing energy consumption. Simultaneously, the evaporator of this invention employs co-current heat exchange, effectively controlling the temperature difference between the catalyst particles and the heat exchange tube wall, avoiding localized overheating, and thus reducing the catalyst deactivation rate during the recovery process. Compared to the high temperatures of traditional processes, this invention only requires 120°C, 0.2MPa steam heating in the evaporator; it promotes the closed-loop use of synthetic raw materials and fundamentally reduces catalyst consumption costs. (Figure 2) Preferably, it also includes a catalyst separation tank, located between the stripping tower and the secondary evaporator; the catalyst separation tank has a cyclone separation zone composed of multiple sets of hydrocyclones in its middle section, using centrifugal force to separate the catalyst and liquid in the slurry mixture; the bottom of the catalyst separation tank is configured as a conical collection trough, collecting part of the catalyst by gravity settling; the bottom of the conical collection trough is provided with a second outlet, which is connected to the inlet of the catalyst regeneration tank via a seventh pipe to transport the catalyst to the catalyst regeneration tank.

[0008] This device also includes a catalyst separation tank, enabling effective separation of the catalyst and liquid before the slurry mixture enters the secondary evaporator. A cyclone separation zone composed of 2-3 sets of hydrocyclones utilizes centrifugal force to efficiently separate the catalyst and liquid in the slurry mixture, improving catalyst recovery. A conical collection trough at the bottom facilitates catalyst collection by gravity settling. The conical structure allows the catalyst to more easily accumulate at the bottom of the trough, facilitating subsequent transportation and regeneration. This represents the initial separation of catalyst particles.

[0009] Preferably, the catalyst regeneration tank has 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 to remove impurities on the catalyst surface. A centrifuge and a drying channel are also provided at the bottom of the tank to separate the spray liquid and enable the catalyst to be recycled.

[0010] In this scheme, the catalyst regeneration tank can efficiently regenerate the catalyst through washing, separation and drying steps. The regenerated catalyst is returned to the slurry bed reactor through the circulation pipeline, realizing the recycling of the catalyst, reducing production costs and reducing the generation of waste.

[0011] Preferably, 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.

[0012] In the catalyst cooling tower of this device, when the gaseous butyraldehyde carrying catalyst particles enters the column through the inlet, the catalyst rises with the airflow. When this airflow passes through the intercepting scraper area, most of the catalyst particles are effectively intercepted due to the scraper's blocking effect. These intercepted catalyst particles, under the influence of gravity, slowly slide down the inclined surface at the bottom of this area and eventually enter the annular spiral pipe set below. Inside the spiral pipe, the catalyst particles flow down the spiral path in an orderly and slow manner, which not only ensures that the catalyst particles are fully dispersed but also greatly extends their contact time with the cooling water. During the sliding process of the catalyst particles in the spiral pipe, cooling water is introduced through the inlet of the cooling tower to exchange heat with the catalyst particles, effectively reducing the catalyst temperature and thus avoiding sintering deactivation problems that may be caused by high-temperature retention. As the catalyst particles continue to slide in the spiral pipe, they eventually reach the end of the spiral pipe and fall onto the inclined ramp inside the tank. To prevent excessive catalyst particle accumulation on the landslide, in addition to its inclined angle, the landslide is equipped with a vibrating motor that periodically vibrates to further promote the sliding and dispersion of the catalyst particles. The landslide design allows the catalyst particles to smoothly slide to the landslide outlet under gravity and be successfully transported to the catalyst regeneration tank through the eighth pipe. This not only extends the service life of the catalyst particles and improves the recovery rate, but also reduces the cost of frequent catalyst replacements and improves the efficiency and sustainability of the entire production process. The gaseous butyraldehyde, carrying the remaining catalyst particles, is discharged from the outlet at the top of the catalyst cooling tower and enters the separation tower through the fifth pipe. In the separation tower, the gaseous butyraldehyde is further effectively separated from the residual catalyst particles. This process ensures the purity of the gaseous butyraldehyde while recovering trace amounts of catalyst particles that may have been carried away by the gas flow.

[0013] Preferably, the top of the stripping tower is provided with a gas outlet and has a layered structure, which includes a wire mesh area, a washing liquid supply area and a packing area from top to bottom, so that the gasified propylene and raw material gas are discharged and recovered from the gas outlet, and the gas outlet is connected to the first condenser through a pipeline.

[0014] In this apparatus, most of the vaporized propylene, a small amount of hydrogen and carbon monoxide bubbles, and a slurry mixture containing the catalyst enter the stripping tower, achieving effective separation of the gas and slurry mixture. Since bubbles are generated during the synthesis process of this invention, these bubbles, during their ascent, not only carry catalyst particles upwards but also hinder the separation and recovery of raw materials. Therefore, this invention incorporates a wire mesh zone and a packing zone in the stripping tower to achieve effective separation of catalyst particles and gas. The wire mesh zone is specially configured with a multi-layer structure. This multi-layer wire mesh design not only effectively intercepts and breaks up rising bubbles, reducing their carrying effect on catalyst particles, but also promotes sufficient contact and mass transfer between the gas and liquid phases through its fine mesh structure, thereby improving separation efficiency. Simultaneously, the multi-layer wire mesh avoids the clogging problem caused by catalyst particles agglomerating into larger particles on the wire mesh surface, as with a single-layer wire mesh. To further optimize the separation effect and catalyst recovery, the packing zone is located below the wire mesh zone, with a certain distance maintained between the packing and the wire mesh. The packing, with its high specific surface area and excellent mass transfer performance, plays a crucial role in intercepting solid catalyst particles and preventing them from rising with the foam and clogging the wire mesh. The packing layer captures and disperses most of the catalyst particles while allowing gas and a small amount of liquid to pass through, creating conditions favorable for gas-liquid mass transfer. The wire mesh layer, on the other hand, focuses on breaking up any remaining foam after passing through the packing layer, ensuring that the foam content in the gas exiting the gas outlet is extremely low, thereby improving the purity of the recovered gas.

[0015] Preferably, 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.

[0016] In this unit, a mass transfer enhancement unit is used in the slurry bed reactor to optimize the butyraldehyde synthesis process. This unit significantly increases the gas-liquid phase contact area by introducing carbon monoxide and hydrogen through its internal structural design. Simultaneously, a nanoparticle catalyst is used, whose high specific surface area and unique electronic structure further enhance reaction efficiency. When hydrogen and carbon monoxide pass through the enhancement unit, they are converted into micron-sized bubbles and fed into the butyraldehyde synthesis reactor, greatly increasing the phase interface area of ​​the reaction system. This increased phase interface area allows for a more complete reaction of propylene, carbon monoxide, and hydrogen within the reaction tower at lower operating pressures, thus significantly improving the butyraldehyde yield. 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 then be treated using flash evaporation technology and directly recycled in the next round of butyraldehyde synthesis, thereby maximizing resource utilization and effectively reducing costs.

[0017] Preferably, the product outlet is connected to the inlet of the butyraldehyde storage tank via an output pipe, and a second condenser is installed on the output pipe 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 the pure butyraldehyde flows into the butyraldehyde storage tank in liquid form.

[0019] Preferably, 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 back into the washing liquid supply area; the washing liquid supply area is provided with multiple spray layers along the side wall of the stripping tower, and the spray layers are composed of washing liquid conveying pipelines and multiple evenly distributed spray heads; the reflux pipeline is provided with a washing liquid storage tank to facilitate the continuous supply of washing liquid.

[0020] In this device, a portion of the butyraldehyde in the butyraldehyde storage tank is recycled as part of the washing liquid, achieving resource recycling and enhancing the functionality and flexibility of the washing liquid supply area. When a portion of the butyraldehyde flows back to the washing liquid supply area through the reflux port and reflux pipeline, a multi-layered spray design further ensures that the washing liquid is evenly and thoroughly sprayed inside the stripping tower, further enhancing the separation and purification effect of the stripping tower. The washing liquid is sprayed out and covers the packing and wire mesh areas, forming a liquid film. This liquid film not only intercepts a small amount of catalyst particles and impurities rising with the bubbles but also removes catalyst particles retained on the wire mesh and packing, washing them and allowing them to descend with the butyraldehyde liquid to the bottom of the gas scrubbing tower, where they are then recycled along the process flow.

[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 an inlet is provided on one side of the catalyst tank to replenish the catalyst.

[0022] Catalysts play a crucial role in the synthesis of butyraldehyde, accelerating the reaction rate and improving product yield and purity. However, with prolonged use, the activity of some catalysts may gradually decrease or even deactivate. Therefore, regular catalyst replacement or regeneration is key to maintaining production efficiency. The regenerated catalyst is returned to the catalyst tank via a circulation pipeline and reused in the reaction. This recycling method not only reduces catalyst waste but also lowers production costs. Furthermore, it allows for the storage of regenerated catalyst, and new catalyst can be added through the feed inlet when the catalyst level in the tank is insufficient or needs replacement, ensuring a constant supply of catalyst in the reactor.

[0023] The mass transfer enhancement unit of this invention belongs to the prior art. Those skilled in the art will understand that the unit can be of different types, such as pneumatic, hydraulic, and pneumatic-hydraulic linkage types; however, the choice between these types depends primarily on the specific operating conditions. As for the connection method between the unit and the slurry bed reactor and other equipment, including the connection structure and location, it needs to be determined according to the structure of the slurry bed reactor and is not specifically limited here.

[0024] In this invention, the pipelines and conduits are equipped with flow control valves, pressure monitoring devices, etc., to ensure the reasonable flow of materials and the stable control of process parameters.

[0025] The present invention also provides a synthesis and recovery method using a low-pressure recovery device for synthesized butyraldehyde, comprising the following steps: sequentially introducing CO, H2, propylene and catalyst into a slurry bed reactor for reaction; after the reaction is complete, recovering the catalyst through a recovery module and obtaining the product.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The present invention achieves efficient utilization of catalyst and maximum recovery of resources by combining a slurry bed reactor with a recovery module. The slurry bed reactor, with its good mixing effect and high mass and heat transfer rate, provides ideal conditions for catalytic reaction, 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 catalyst generated during the reaction, improving the recovery rate of raw materials and avoiding waste of resources and environmental pollution.

[0027] (2) The present invention uses a combination of evaporator and pressure relief valve to form a multi-stage pressure relief effect, which reduces the boiling point of butyraldehyde and allows butyraldehyde to be effectively vaporized at a relatively low temperature. The multi-stage pressure release prevents the catalyst from being deactivated due to high temperature and rapid pressure changes during the vaporization process. In addition, the catalyst cooling tower is used to cool the catalyst carrying heat in time after the butyraldehyde is vaporized, which effectively reduces the temperature of the catalyst, reduces the reduction of catalyst activity and structural damage caused by temperature, and further improves the catalyst recovery rate.

[0028] (3) The recycling module in this invention is designed with a multi-stage recycling process, which enables each raw material component to be separated and purified in detail, ensuring that butyraldehyde produced during the synthesis process and all input raw materials can be recycled and reused to the greatest extent.

[0029] (4) The synthesis and recovery method of the low-pressure recovery device for synthesizing butyraldehyde provided by this invention reduces production costs and environmental burden. By recycling the catalyst and recovering and reusing resources, the consumption of new catalysts and raw materials is reduced, thereby lowering production costs. 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. Attached Figure Description

[0030] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. 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 a conventional process.

[0031] Reference numerals: 1-Slurry bed reactor, 2-First-stage evaporator, 3-Stripping tower, 4-Catalyst separator, 5-Second-stage evaporator, 6-Catalyst cooling tower, 7-Separation tower, 8-Catalyst regeneration tank, 9-Butyraldehyde storage tank, 10-Catalyst tank, 11-First-stage pressure relief valve, 12-Second-stage 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 Pipeline, 21-Sixth Pipeline, 22-Seventh Pipeline, 23-Eighth Pipeline, 24-Ninth Pipeline, 25-Tenth Pipeline, 26-Circulation Pipeline, 27-Return Pipeline, 28-Washing Liquid Storage Tank, 31-Production Pipeline, 101-Mass Transfer Enhancement Unit, 102-Synthetic Gas Feed Pipe, 103-Propylene Feed Pipe, 301-Wire Mesh Area, 302-Washing Liquid Supply Area, 303-Packaging Area, 601-Interception Scraper Area, 602-Spiral Pipeline, 603-Slide. Detailed Implementation

[0032] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and specific embodiments. However, those skilled in the art will understand that the embodiments described below are some embodiments of the present invention, but not all embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0033] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0034] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0035] The present invention provides a low-pressure recovery device for synthesized butyraldehyde, comprising: a slurry bed reactor 1 and a recovery module. In traditional butyraldehyde synthesis systems, the pressure inside the butyraldehyde synthesis reactor is relatively high, typically maintained at 18-19 atm, and the contact area between the gas and liquid phases is limited. This situation greatly restricts sufficient contact between reactants, thus affecting the reaction. To ensure the reaction continues, the reactor temperature is often increased by 10-15°C. However, increasing the temperature adversely affects the catalyst recovery effect, but not increasing the temperature will prevent the reaction from proceeding completely, and the product yield will also decrease.

[0036] 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 conventional 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 the evaporator, further reducing the catalyst deactivation rate and improving catalyst recovery. Therefore, compared with traditional technologies, this invention, through staged pressure reduction and the supplementary 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.

[0037] To more clearly illustrate the technical solutions in this invention, specific embodiments are described below.

[0038] Example 1 Referring to Figure 1, the present invention is a low-pressure recovery device for synthesized 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 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.

[0039] 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.

[0040] The gasified propylene and the remaining slurry mixture enter the stripping process through the second pipe 17. In the stripping tower 3, most of the gasified propylene and a small amount of hydrogen and carbon monoxide bubbles are discharged through the top gas outlet via the wire mesh 301 and the packing zone 303. The mixture then passes through the tenth pipe 25 and is condensed by the first condenser 13 on the pipe before flowing into the raw material recovery tank 15 for storage, which is convenient for use in the next round of synthesis.

[0041] The butyraldehyde product, heavy component impurities, and catalyst mixture discharged from the bottom of stripping tower 3 enter catalyst separator 4 to separate the catalyst. The separated catalyst particles are then transported from the second outlet at the bottom of catalyst separator 4 to catalyst regeneration tank 8 via seventh pipe 22. Utilizing a cyclone separation zone composed of three sets of hydrocyclones and the gravity settling effect of a conical collection trough, the catalyst is separated from the mixture. The separated catalyst is then transported from the second outlet at the bottom of catalyst separator 4 to catalyst regeneration tank 8 via seventh pipe 22 for regeneration to remove surface heavy component impurities.

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

[0043] The gasified butyraldehyde and the remaining catalyst particles enter the catalyst cooling tower 6 through the fourth pipe 19. When the gas is in the intercepting scraper zone 601, it reacts with the scraper during the upward process, preventing the catalyst particles from continuing to rise with the airflow. The scraper effectively intercepts most of the catalyst particles. The intercepted catalyst particles slide down into the spiral pipe 602. During the sliding process and when the catalyst is on the slide 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 pipe 23.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] Example 2 This invention is a low-pressure recovery device for synthesized butyraldehyde. In this example, 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.

[0048] 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.

[0049] The gasified propylene and the remaining slurry mixture enter the stripping process through the second pipe 17. In the stripping tower 3, most of the gasified propylene and a small amount of hydrogen and carbon monoxide bubbles are discharged through the top gas outlet via the wire mesh 301 and the packing zone 303. The mixture then passes through the tenth pipe 25 and is condensed by the first condenser 13 on the pipe before flowing into the raw material recovery tank 15 for storage, which is convenient for use in the next round of synthesis.

[0050] The butyraldehyde product, heavy component impurities, and catalyst mixture discharged from the bottom of stripping tower 3 enter catalyst separator 4 to separate the catalyst. The separated catalyst particles are then transported from the second outlet at the bottom of catalyst separator 4 to catalyst regeneration tank 8 via seventh pipe 22. Utilizing a cyclone separation zone composed of three sets of hydrocyclones and the gravity settling effect of a conical collection trough, the catalyst is separated from the mixture. The separated catalyst is then transported from the second outlet at the bottom of catalyst separator 4 to catalyst regeneration tank 8 via seventh pipe 22 for regeneration to remove surface heavy component impurities.

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

[0052] The gasified butyraldehyde and the remaining catalyst particles enter the catalyst cooling tower 6 through the fourth pipe 19. When the gas is in the intercepting scraper zone 601, it reacts with the scraper during the upward process, preventing the catalyst particles from continuing to rise with the airflow. The scraper effectively intercepts most of the catalyst particles. The intercepted catalyst particles slide down into the spiral pipe 602. During the sliding process and when the catalyst is on the slide 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 pipe 23.

[0053] 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.

[0054] 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.

[0055] 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.

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

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

[0058] Comparative Example 2 is implemented in the same way as Example 1, except that the evaporator is heated by 0.4MPa steam and the evaporator is changed to a parallel flow mode.

[0059] Comparative Example 3 is implemented in the same way as Example 1, except that a catalyst regeneration tank is not used.

[0060] Comparative Example 4 is implemented in the same way as Example 1, except that a catalyst cooling tower is not used.

[0061] Comparative Example 5 is implemented in the same way as Example 1, except that a pressure relief valve is not used.

[0062] Comparative Example 6 is implemented in the same way as Example 1, except that only the wire mesh area is used.

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

[0064] As shown in the table above, and through Example 1 and Comparative Example 1, this invention, by employing a mass transfer enhancement unit, reacts hydrogen and carbon monoxide within this unit, breaking them down into nanoscale bubbles in the slurry-bed reactor for butyraldehyde synthesis, thereby increasing the phase interface area of ​​the butyraldehyde synthesis reaction system. This increased phase interface area allows for a reduction in the operating pressure within the butyraldehyde synthesis reactor, while simultaneously promoting a more complete and thorough reaction of propylene, carbon monoxide, and hydrogen within the reaction tower. Compared to Comparative Example 1, this invention, through the application of the mass transfer enhancement unit, achieves more uniform gas-liquid mixing, higher reaction efficiency, and effectively improves the butyraldehyde synthesis yield while maintaining a high raw material recovery rate.

[0065] As can be seen from Examples 1, 2, and 5, the propylene recovery rate (86.7%), carbon monoxide recovery rate, and hydrogen recovery rate (81.4%) in Comparative Example 2 were all lower than those in Example 1, and the catalyst recycling capacity (72.2%) decreased. In Comparative Example 5, due to the lack of a pressure relief valve, sudden pressure changes caused turbulence in the slurry mixture, and the changes in evaporation conditions affected the catalyst separation and regeneration. The catalyst recycling capacity was also low (70.2%). Therefore, this invention gradually releases pressure through a first-stage pressure relief (12→4 atm) and a second-stage pressure relief (4→1.3 atm) to avoid catalyst breakage or gas escape caused by sudden pressure changes. Furthermore, by combining it with an evaporator, the internal pressure of the evaporator is reduced, enabling the use of 0.2 MPa steam, resulting in lower energy consumption, significantly reduced catalyst deactivation, and significantly improved economic benefits, with a small pressure reduction per stage.

[0066] As can be seen from Examples 1 and Comparative Examples 3 and 4, the catalyst recycling capacity of Comparative Examples 3-4 decreased significantly (72.5%, 71.3%). Impurities gradually accumulated in the catalyst during the reaction could not be removed, leading to rapid catalytic activity decay. Furthermore, the catalyst could not be cooled promptly after the reaction, remaining in a high-temperature environment for an extended period, accelerating the catalyst deactivation rate and further reducing its recycling capacity. The spiral pipe cooling system effectively suppressed catalyst sintering at high temperatures, maintaining the catalyst's structure and activity. This invention, through the combination of a catalyst cooling tower and a catalyst regeneration tank in a recovery module, effectively removes impurities such as carbon and sulfides accumulated on the catalyst surface, thereby restoring its active sites and maintaining high catalyst activity.

[0067] Examples 3 and 6 also demonstrate the crucial role of wire mesh and packing in the stripping tower. Example 1 employs multi-layered wire mesh (to intercept large particles of impurities) and high-efficiency packing (to increase gas-liquid contact), resulting in higher separation efficiency. The single-layer structure of Example 2 leads to impurity penetration, increased catalyst surface contamination, and decreased circulation capacity. Comparative Example 6 uses only wire mesh, which, under the same separation conditions, can achieve separation, but compared to the combination of wire mesh and packing, it cannot meet the requirements of high-quality products and high raw material recovery rates of this invention.

[0068] The apparatus of this invention not only significantly improves the efficiency of butyraldehyde synthesis and greatly reduces energy consumption, but also effectively increases the recovery rate of raw materials while reducing catalyst loss, fundamentally solving many problems existing in the prior art. It provides an efficient and sustainable solution for the industrial upgrading of butyraldehyde synthesis, powerfully promoting 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 not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to 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; 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.

10. A synthesis recovery method applied in the low-pressure recovery apparatus for synthetic butyraldehyde as described in any one of claims 1-9, characterized in that, Includes the following steps: CO, H2, propylene, and catalyst are sequentially introduced into a slurry bed reactor for reaction. After the reaction is complete, the catalyst is recovered through a recovery module, and the product is obtained.

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