Catalyst separation system for preparing butyraldehyde through propylene carbonylation
The separation system, which combines a flash tank and a low-pressure evaporator, solves the problems of complex catalyst-product separation equipment and high-temperature deactivation, achieving the effects of simplified process, extended catalyst life and reduced cost.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-27
- Publication Date
- 2026-03-24
AI Technical Summary
Existing processes for separating catalysts from products after propylene carbonylation are complex, have high maintenance costs, and the catalysts are prone to deactivation at high temperatures, resulting in short service life.
A separation system combining a flash tank and a low-pressure evaporator is used. The flash tank initially separates unreacted materials, while the low-pressure evaporator further separates the catalyst solution. Non-condensable gas is circulated to the top of the low-pressure evaporator to regulate the temperature and prevent catalyst deactivation at high temperatures.
It simplifies the equipment process, extends catalyst life, reduces process costs, and improves separation efficiency and energy utilization.
Smart Images
Figure CN224024273U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the technical field of chemical synthesis, and particularly relates to a catalyst separation system for preparing butyraldehyde through propylene carbonylation. BACKGROUND
[0002] Butanol and octanol are important organic chemical, fine chemical and chemical auxiliary raw materials, and are widely used in the synthesis of lubricants, solvents, defoaming agents, additives, antioxidants and the like and in the industries of photography, printing and dyeing, paper sizing and the like. Butanol and octanol can be produced by the method of carbonyl synthesis in the same set of devices, and are therefore commonly referred to as butyl octanol. The wide use of butyl octanol promotes the increase of the amount and yield of butyl octanol year by year.
[0003] At present, the process of producing butyraldehyde through propylene carbonylation reaction is most widely used in butyl octanol production. In the process, butyraldehyde is used as a solvent, and propylene and synthesis gas are reacted in the presence of a catalyst to produce butyraldehyde and isobutyraldehyde. After the reaction is completed, the catalyst is separated from the butyraldehyde solution through an evaporation process, and the separated catalyst can be recycled. The butyraldehyde / isobutyraldehyde condensed after evaporation can be first hydrogenated to produce n-butanol and isobutanol, and the n-butanol and isobutanol products can be obtained through rectification separation. Secondly, the butyraldehyde / isobutyraldehyde can be separated into butyraldehyde and isobutyraldehyde through an isomer tower, and the isobutyraldehyde is used as a byproduct. The butyraldehyde is condensed and dehydrated under the catalysis of sodium hydroxide to produce octylene aldehyde, and the crude octanol is produced by hydrogenating the octylene aldehyde. The product octanol is obtained through rectification.
[0004] In the overall process, the catalyst used in the propylene carbonylation process is an important production cost. In recent years, the separation and recovery of the catalyst from the post-reaction material have become the focus of research in butyl octanol production. In the prior art, the post-reaction material output from the reaction kettle is input into the top of the high-pressure evaporator, the product butyraldehyde is vaporized and condensed, and then enters the propylene absorption tower. The crude butyraldehyde output from the bottom of the propylene absorption tower enters the gas stripping tower to separate the propylene and propane dissolved therein, and the butyraldehyde product is obtained. The catalyst solution concentrated in the high-pressure evaporator is cooled and then enters the low-pressure evaporator, and is further separated, concentrated, cooled and returned to the reactor. The gas product output from the low-pressure evaporator is condensed and then enters the low-pressure evaporator condensate tank, and the incondensable gas is discharged to the flare, and the condensed crude butyraldehyde is added to the propylene absorption tower. The overall process involves multiple devices and equipment such as the high-pressure evaporator, the propylene absorption tower, the gas stripping tower and the low-pressure evaporator, and the process is relatively complex, and the equipment maintenance and repair costs are high. UTILITY MODEL CONTENTS
[0005] To address the shortcomings of existing technologies, this utility model discloses a catalyst separation system for the carbonylation of propylene to butyraldehyde. This system simplifies the equipment and operation process, and can maintain a suitable temperature during the separation process to avoid high-temperature deactivation of the catalyst, thereby improving the catalyst's service life and reducing process costs.
[0006] To achieve the above technical objectives, this utility model proposes a catalyst separation system for the carbonylation of propylene to butyraldehyde, the system comprising:
[0007] The flash evaporator has an inlet for feeding the material after the propylene carbonylation reaction, and its gas phase outlet is connected to a separation tank via a first condenser; the gas phase outlet of the separation tank is connected to the upstream reaction process.
[0008] A low-pressure evaporator is provided, wherein the liquid phase outlet of the flash tank is connected to the low-pressure evaporator; a collection tank is connected to the lower part of the low-pressure evaporator; the gas phase outlet of the collection tank is connected to the condensate receiving tank via a second condenser, and the gas phase outlet of the condensate receiving tank is connected to the top of the low-pressure evaporator via a compressor; the liquid phase outlet of the collection tank is used to output the catalyst solution, and the liquid phase outlet of the condensate receiving tank is used to output crude butyraldehyde.
[0009] In the above technical solution, the unreacted material is fed into the flash evaporator after the reaction of propylene and syngas, which can achieve the separation of unreacted material from the catalyst solution and products. The unreacted raw materials and some products are output from the gas phase outlet of the flash evaporator. After condensation, they undergo further gas-liquid separation in the separation tank. The gas phase material output from the separation tank is the unreacted material, which will be returned to the upstream reaction process for recycling. This process not only simplifies the equipment, but also the operating temperature of the flash evaporation process is lower than that of the high-pressure evaporator, which is beneficial to maintaining the catalytic activity of the catalyst.
[0010] Furthermore, the material separated from the unreacted raw materials is fed into a low-pressure evaporator for the separation of butyraldehyde and the catalyst solution. The catalyst solution obtained after separation in the low-pressure evaporator is output from the liquid phase outlet of the low-pressure evaporator collection tank. The gaseous material output from the collection tank is condensed and the condensate is separated into gas and liquid phases in the receiving tank. The resulting non-condensable gas is compressed and fed into the top of the low-pressure evaporator as circulating gas. This can promote the reduction of the liquid film thickness in the low-pressure evaporator to accelerate evaporation. At the same time, it can reduce and regulate the evaporation temperature to help prevent high-temperature deactivation of the catalyst, extend the service life of the catalyst, and further reduce the process cost of propylene carbonylation. The recycling of non-condensable gas is green and environmentally friendly, and saves energy.
[0011] In the above technical solution, crude butyraldehyde is output from the liquid phase outlet of the condensate receiving tank. This portion of crude butyraldehyde will be fed into the downstream stabilizer tower for further separation of propylene from the crude butyraldehyde to obtain qualified butyraldehyde product. The catalyst solution is output from the liquid phase outlet of the collection tank. This portion of the catalyst solution can be recycled back to the upstream reaction process, or a portion of it can be fed into the downstream catalyst washing system.
[0012] Compared to traditional high- and low-pressure evaporation processes for separating catalysts and products, this invention offers the following advantages: It employs a flash evaporator combined with a low-pressure evaporator to separate products from the catalyst in the propylene carbonylation reaction, simplifying the process equipment. By circulating the non-condensable gas obtained from low-pressure evaporation to the top of the evaporator, the efficiency of low-pressure evaporation is improved, thereby reducing the evaporation temperature. This prevents high-temperature catalyst deactivation, extends the catalyst's lifespan in the propylene carbonylation reaction, and lowers process costs. This invention is highly operable, economical, and suitable for industrial production. Attached Figure Description
[0013] The accompanying drawings, which form part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an undue limitation of the present invention. In the drawings:
[0014] Figure 1 The diagram shows the structure of the catalyst separation system of this invention for the carbonylation of propylene to butyraldehyde.
[0015] The above figures include the following reference numerals:
[0016] 1-Flash tank, 2-Separation tank, 3-Low-pressure evaporator, 4-Collection tank, 5-Condensate receiving tank, 61-First condenser, 62-Second condenser, 63-Third condenser, 64-Fourth condenser, 71-First switching valve, 72-Second switching valve, 73-Third switching valve, 74-Fourth switching valve, 81-First level gauge, 82-First pressure gauge, 83-Second pressure gauge, 84-Second level gauge, 85-Flow meter, 9-Compressor. Detailed Implementation
[0017] To facilitate understanding of this utility model, a more comprehensive description of it will be provided below, along with preferred embodiments. However, it should be understood that these embodiments are merely for more detailed explanation and should not be construed as limiting the utility model in any way, i.e., not limiting the scope of protection of this utility model.
[0018] Unless otherwise defined, the technical terms used in the following embodiments have the same meanings as commonly understood by those skilled in the art to which this invention pertains. Unless otherwise specified, the experimental reagents used in the following embodiments are conventional biochemical reagents; and the experimental methods described are conventional methods.
[0019] Example 1
[0020] A catalyst separation system for the carbonylation of propylene to butyraldehyde, such as Figure 1 As shown, the system includes:
[0021] Flash tank 1 has a feed inlet for feeding the material after the propylene carbonylation reaction. The gas phase outlet of flash tank 1 is connected to separation tank 2 via first condenser 61. The gas phase outlet of separation tank 2 is connected to the upstream reaction process.
[0022] The liquid phase outlet of the flash tank 1 is connected to the low-pressure evaporator 3; the lower part of the low-pressure evaporator 3 is connected to the collection tank 4; the gas phase outlet of the collection tank 4 is connected to the condensate receiving tank 5 via the second condenser 62; the gas phase outlet of the condensate receiving tank 5 is connected to the top of the low-pressure evaporator 3 via the compressor 9; the liquid phase outlet of the collection tank 4 is used to output the catalyst solution, and the liquid phase outlet of the condensate receiving tank 5 is used to output crude butyraldehyde.
[0023] The process of the catalyst separation system for the carbonylation of propylene to butyraldehyde in this embodiment includes: (1) The material after the carbonylation reaction of propylene is fed into flash tank 1, and after flash concentration, the gaseous material is output from the gas outlet of flash tank 1. After being condensed by the first condenser 61, it is separated into gas and liquid in separation tank 2. The unreacted raw materials (such as propylene, synthesis gas, etc.) are separated as gas and returned to the upstream reaction process for recycling. The liquid phase obtained is a solution containing butyraldehyde; (2) The liquid phase obtained after flashing in flash tank 1 is fed into low-pressure evaporator 3 for further evaporation; The gaseous material obtained from the collection tank 4 of low-pressure evaporator 3 is condensed by the second condenser 62 and fed into condensate receiving tank 5 for gas-liquid separation. The obtained non-condensable gas will be returned to the top of low-pressure steam to regulate the efficiency of low-pressure falling film evaporation. At the same time, it can promote regulation and reduce the temperature of low-pressure evaporation, avoid catalyst deactivation due to high temperature, thereby extending the service life of the catalyst and saving process costs; The liquid phase obtained from the gas-liquid separation in condensate receiving tank 5 is crude butyraldehyde, which will be fed into the downstream stabilizer tower. The liquid material obtained from the collection tank 4 of the low-pressure evaporator 3 is a catalyst solution. This catalyst solution can be directly returned to the upstream reaction process and / or a portion can be input into the downstream catalyst washing process, etc., to realize the recycling of the catalyst.
[0024] It should be noted that this utility model does not limit the specific structure of the flash tank, separation tank, collection tank, condensate receiving tank, etc., and can be selected as container-type equipment. Further, it can be selected as equipment with a demister and butyraldehyde circulating spray pipe on the top of the container, thereby effectively preventing catalyst loss during the separation process. This utility model does not limit the specific structure of the low-pressure evaporator used, and can be selected as an effective thin-film forming vertical falling film evaporator. Those skilled in the art can select flash tanks, separation tanks, collection tanks, condensate receiving tanks and low-pressure evaporators with appropriate structures as needed, without limiting the protection scope of this utility model.
[0025] It should be noted that in actual processes, in order to improve process efficiency, those skilled in the art may, based on this invention, install circulating pumps, compressors, or other devices or equipment on pipelines used for circulating liquid or gaseous materials to improve material flow efficiency, without limiting the scope of protection of this invention.
[0026] Example 2
[0027] Based on the catalyst separation system for the carbonylation of propylene to butyraldehyde shown in Example 1, this example optimizes the connection method of the liquid phase outlet of the separation tank 2.
[0028] Optionally, the liquid phase outlet of the separation tank 2 is connected to the feed inlet of the flash tank 1, thereby recovering the product entrained in the gaseous material obtained by flashing in the flash tank 1 and improving the product yield.
[0029] Optionally, a first switching valve 71 is provided on the pipeline connecting the liquid phase outlet of the separation tank 2 and the feed inlet of the flash tank 1; the separation tank 2 is provided with a first level gauge 81 that is signal-connected to the first switching valve 71, so that the first switching valve 71 can be interlocked and controlled by the first level gauge 81 during the actual process, thereby further regulating the gas-liquid separation and product recovery process of the separation tank 2 and improving the process operability.
[0030] Alternatively, a flow meter 85 connected to the first switching valve 71 and the first level gauge 81 is provided on the pipeline connecting the liquid phase outlet of the separation tank 2 and the feed inlet of the flash tank 1, thereby facilitating coordinated control of the flash operation of the flash tank 1 and the reflux of the separation tank 2 and improving the operability of the system.
[0031] Alternatively, a third condenser 63 is provided on the pipeline connecting the liquid phase outlet of the separation tank 2 and the feed inlet of the flash tank 1. The third condenser 63 can heat the liquid phase material returning from the separation tank 2 to the flash tank 1, which is beneficial for the flash separation of this part of the material in the flash tank and improves the separation efficiency of the catalyst and the product in the flash tank 1.
[0032] Example 3
[0033] Based on the catalyst separation system for the carbonylation of propylene to butyraldehyde shown in Example 1, this example optimizes the connection method of the gas phase outlet of separation tank 2.
[0034] Optionally, a first branch is provided on the pipeline connecting the gas phase outlet of the separator 2 for discharging the purge gas. Through the first branch, some by-products and unreacted substances, such as propane and propylene, can be discharged in a timely and appropriate manner, which is beneficial to the control of upstream reaction processes and the effective recovery of propylene and reduction of propane accumulation in the overall process route. Further, the first branch can be connected to the fuel gas pipeline network or other processes.
[0035] Optionally, a second switching valve 72 is provided on the first branch; a first pressure gauge 82 connected to the second switching valve 72 is provided on the pipeline connecting the flash tank 1 and the separation tank 2. This facilitates the interlocking of the second switching valve 72 and the first pressure gauge 82 during actual operation. The pressure of the gaseous material output from the flash tank 1 can be automatically controlled by closing the second switching valve 72, thereby further controlling the operating pressure of the flash tank 1, promoting stable operation of the flash evaporation process, and improving flash evaporation efficiency.
[0036] Example 4
[0037] Based on the catalyst separation system for the carbonylation of propylene to butyraldehyde shown in Example 1, this example optimizes the connection method of the gas phase outlet of the condensate receiving tank 5.
[0038] Optionally, a second branch is provided on the pipeline connecting the gas phase outlet of the condensate receiving tank 5 for discharging non-condensable gases. Discharging a portion of the non-condensable gases through this second branch facilitates the control of the circulation rate of non-condensable gases back to the low-pressure evaporator 3, further regulating the low-pressure evaporation efficiency. Further optionally, the second branch can be connected to a fuel gas pipeline or other processes.
[0039] Optionally, a third switch valve 73 is provided on the second branch, and a second pressure gauge 83 connected to the third switch valve 73 is provided on the pipeline connecting the collection tank 4 and the condensate receiving tank 5. Thus, the pressure of the gaseous material output from the low-pressure evaporator 3 can be automatically controlled by closing the third switch valve 73, thereby further controlling the operating pressure of the low-pressure evaporator 3, promoting the stable operation of the overall system, improving the catalyst separation efficiency and maintaining the catalyst activity.
[0040] Example 5
[0041] Based on the catalyst separation system for the carbonylation of propylene to butyraldehyde shown in Example 1, this example optimizes the connection method of the liquid phase outlet of the collection tank 4.
[0042] Optionally, a fourth switching valve 74 is provided on the pipeline connected to the liquid phase outlet of the collection tank 4, and a second level gauge 84 is provided in the collection tank 4 that is signal-connected to the fourth switching valve 74. In actual operation, the input and output of the catalyst solution after separation can be controlled by the interlock between the second level gauge 84 and the fourth switching valve 74, and the low-pressure flash evaporation separation efficiency of the low-pressure evaporator 3 can be further controlled, thereby improving the automation level of the process.
[0043] Optionally, a fourth condenser 64 is provided on the pipeline connected to the liquid phase outlet of the collection tank 4. The catalyst solution separated from the collection tank 4 is further cooled by the fourth condenser 64, which helps to maintain the activity of the catalyst in subsequent process steps and reduce process costs.
[0044] It should be noted that the above description is a further detailed explanation of the present invention in conjunction with specific embodiments, and should not be construed as limiting the specific implementation of the present invention to these descriptions; the dimensional data in this embodiment do not limit the technical solution, but merely illustrate one specific working condition. For those skilled in the art to which this invention pertains, several simple improvements and modifications can be made without departing from the concept of the present invention, and all such improvements and modifications should be considered to fall within the scope of protection of the present invention.
Claims
1. A catalyst separation system for the carbonylation of propylene to butyraldehyde, characterized in that, include: Flash tank (1), the feed port of the flash tank (1) is used to input the material after the propylene carbonylation reaction, and the gas phase outlet of the flash tank (1) is connected to the separation tank (2) via the first condenser (61); the gas phase outlet of the separation tank (2) is connected to the upstream reaction process. The low-pressure evaporator (3) is connected to the liquid phase outlet of the flash tank (1); the lower part of the low-pressure evaporator (3) is connected to the collection tank (4); the gas phase outlet of the collection tank (4) is connected to the condensate receiving tank (5) via the second condenser (62); the gas phase outlet of the condensate receiving tank (5) is connected to the top of the low-pressure evaporator (3) via the compressor (9); the liquid phase outlet of the collection tank (4) is used to output the catalyst solution; and the liquid phase outlet of the condensate receiving tank (5) is used to output crude butyraldehyde.
2. The catalyst separation system for the carbonylation of propylene to butyraldehyde according to claim 1, characterized in that, The liquid phase outlet of the separation tank (2) is connected to the feed inlet of the flash tank (1).
3. The catalyst separation system for the carbonylation of propylene to butyraldehyde according to claim 2, characterized in that, A first switching valve (71) is provided on the pipeline connecting the liquid phase outlet of the separation tank (2) and the feed inlet of the flash tank (1); the separation tank (2) is provided with a first level gauge (81) that is signal-connected to the first switching valve (71).
4. The catalyst separation system for the carbonylation of propylene to butyraldehyde according to claim 2, characterized in that, A third condenser (63) is provided on the pipeline connecting the liquid phase outlet of the separation tank (2) and the feed inlet of the flash tank (1).
5. The catalyst separation system for the carbonylation of propylene to butyraldehyde according to claim 1, characterized in that, The pipeline connecting the gas phase outlet of the separation tank (2) is provided with a first branch for discharging the vented gas.
6. The catalyst separation system for the carbonylation of propylene to butyraldehyde according to claim 5, characterized in that, A second switching valve (72) is provided on the first branch; a first pressure gauge (82) connected to the second switching valve (72) is provided on the pipeline connecting the flash tank (1) and the separation tank (2).
7. The catalyst separation system for the carbonylation of propylene to butyraldehyde according to claim 1, characterized in that, A second branch for discharging non-condensable gas is provided on the pipeline connecting the gas phase outlet of the condensate receiving tank (5).
8. The catalyst separation system for the carbonylation of propylene to butyraldehyde according to claim 7, characterized in that, A third switch valve (73) is provided on the second branch, and a second pressure gauge (83) connected to the signal of the third switch valve (73) is provided on the pipeline connecting the collection tank (4) and the condensate receiving tank (5).
9. The catalyst separation system for the carbonylation of propylene to butyraldehyde according to claim 1, characterized in that, A fourth switch valve (74) is provided on the pipeline connected to the liquid phase outlet of the collection tank (4), and a second level gauge (84) is provided on the collection tank (4) and is connected to the signal of the fourth switch valve (74).
10. The catalyst separation system for the carbonylation of propylene to butyraldehyde according to claim 1, characterized in that, A fourth condenser (64) is provided on the pipeline connected to the liquid phase outlet of the collection tank (4).