Reactor for preparing isononanal through hydroformylation of isooctene

Abstract

The utility model relates to the technical field of chemical equipment, and discloses a reactor for preparing isononanal through hydroformylation of isooctene, which comprises a shell with an inner cavity, a polytetrafluoroethylene filter membrane is arranged in the inner cavity, and the inner cavity is divided into a first chamber and a second chamber which are communicated with each other by the polytetrafluoroethylene filter membrane; a first inlet allowing isooctene to enter and a first outlet allowing finished products to be discharged are formed in the cavity wall of the first cavity, the first inlet and the first outlet are both communicated with the first cavity, and a second inlet allowing a catalyst and a ligand to enter is further formed in the cavity wall of the second cavity; and the shell is also provided with a gas inlet which is communicated with the inner cavity and is used for conveying synthesis gas. When isooctene enters the second chamber through the first chamber, the polytetrafluoroethylene filter membrane can be backwashed, so that a catalyst and a ligand attached to the polytetrafluoroethylene filter membrane return to the second chamber, the polytetrafluoroethylene filter membrane is not easy to block, the loss of the catalyst and the ligand is reduced, the service life of the polytetrafluoroethylene filter membrane is prolonged, and smooth preparation of isononanal is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of chemical equipment, in particular to a reactor for preparing isononaldehyde by hydroformylation of isooctene. Background Art

[0002] Olefin hydroformylation, the reaction of α-olefins with synthesis gas to produce higher-carbon linear aldehydes, is crucial to the chemical industry because the various aldehydes produced are widely used in fragrances, surfactants, plasticizers, and solvents. Among the many olefin hydroformylation reactions, the hydroformylation of isooctene to isononanal holds profound significance.

[0003] Isononanal is an important organic chemical raw material, widely used in plasticizers, surfactants, fragrances, detergents, and organic synthesis. Isononanal can be converted into a variety of high-value-added fine chemical products through subsequent conversion. Reduction yields isononanol, and oxidation yields isononanoic acid. Due to its unique properties, such as excellent wettability, permeability, and emulsification, highly branched isononanoic acid has important applications in lubricants, industrial detergents, and other industries.

[0004] At present, the domestic production technology for preparing isononanal from isooctene is still basically in the laboratory stage and has not yet entered industrial application. Current research mainly focuses on homogeneous catalytic systems, water / oil two-phase catalytic systems, and multiphase solid-supported catalytic systems.

[0005] In industry, hydroformylation catalysts have gone through four generations of catalysts. The first generation of hydroformylation catalysts is cobalt-based catalysts. Because cobalt has low reactivity, the reaction usually requires harsh reaction conditions, such as extremely high reaction pressure and high reaction temperature. The second generation of hydroformylation catalysts is rhodium-based catalytic system. The earliest ligand used in ligand-modified rhodium-based catalysts was triphenylphosphine. Subsequently, ligand rhodium catalysts developed rapidly, and the hydroformylation reaction also made great progress. Among them, rhodium catalysts modified with partial phosphine ligands showed extremely excellent reactivity and linear aldehyde selectivity. Although ligand rhodium catalysts have excellent catalytic effects, they are plagued by the separation of catalyst and product. Therefore, the third generation of hydroformylation catalysts mainly use two-phase systems, that is, using water-soluble or ionic liquids to solidify the catalyst, so that it can be easily separated from the organic product. In addition, other alternative metals are also under continuous research, such as Ru, Pt, Pd, etc. The fourth generation of rhodium / phosphine water-soluble HRh(CO)(TPPTS)3 catalyst has a very high boiling point. The high carbon aldehydes / alcohols prepared from high carbon olefins must be separated from the catalyst by flash distillation at high temperature, and the rhodium catalyst will decompose and be lost at high temperature.

[0006] Rhodium catalysts are 1,000 times more active than cobalt catalysts, but their price is 3,500 times that of cobalt. Homogeneous rhodium-phosphine catalytic systems can demonstrate excellent conversion and selectivity in hydroformylation reactions. However, the catalyst is difficult to separate from the product for reuse. Rhodium is a precious metal, and its loss in industry significantly increases process costs. In current processes, the reaction liquid after hydroformylation must undergo flash evaporation and distillation to separate the catalytic system from the product and raw materials. Heat exposure to the catalyst system during this process also reduces the catalyst's lifespan. Consequently, existing technologies for isooctene hydroformylation suffer from difficulties recovering the catalyst and ligand.

[0007] Patent authorization publication number CN218222430U discloses a reactor for continuous olefin hydroformylation reaction, including a shell, wherein the top of the shell is provided with a synthesis gas inlet, the bottom is provided with an isononanal / unreacted diisobutylene outlet, the upper part of one side is provided with a diisobutylene inlet and a temperature-control oil outlet, and the lower part of the other side is provided with a temperature-control oil inlet; the upper part of the shell is provided with a synthesis gas inlet distribution ring, and the bottom is provided with a filter device, which is composed of multiple layers of metal powder sintered plates stacked together, and a polytetrafluoroethylene filter membrane is provided between adjacent metal powder sintered plates.

[0008] The reactor described above includes a filtration device containing a polytetrafluoroethylene (PTFE) filter membrane, which filters the catalyst and macromolecular ligands to separate the catalyst from isononanal. However, the reactor described above is a vertical reactor. Over extended use, the catalyst can accumulate on the PTFE filter membrane, clogging it and affecting the isononanal production process and the service life of the membrane. Utility Model Content

[0009] The purpose of the utility model is to provide a reactor for preparing isononanal by hydroformylation of isooctene, so as to solve the problem in the prior art that the catalyst of the reactor may clog the polytetrafluoroethylene filter membrane, thereby affecting the preparation process of isononanal and the service life of the polytetrafluoroethylene filter membrane.

[0010] In order to achieve the above object, the utility model provides a reactor for preparing isononanal by hydroformylation of isooctene, comprising a shell having an inner cavity, wherein a polytetrafluoroethylene filter membrane is provided in the inner cavity, and the polytetrafluoroethylene filter membrane divides the inner cavity into a first chamber and a second chamber that are interconnected;

[0011] The wall of the first chamber is provided with a first inlet for isooctene to enter and a first outlet for finished product to be discharged, the first inlet and the first outlet are both connected to the first chamber, and the wall of the second chamber is further provided with a second inlet for catalyst and ligand to enter;

[0012] The shell is also provided with an air inlet which is in communication with the inner cavity for delivering synthesis gas.

[0013] Preferably, the first inlet and the first outlet are arranged symmetrically with the center line of the shell as the axis.

[0014] Preferably, there are at least two groups of polytetrafluoroethylene filter membranes, and each group of polytetrafluoroethylene filter membranes is stacked along the center line direction of the shell.

[0015] Preferably, the air inlet is arranged on the cavity wall of the first cavity, and the air inlet is located on the center line of the shell.

[0016] Preferably, it further comprises an exhaust port, which is arranged on the cavity wall of the second cavity, and the direction of the exhaust port is perpendicular to the center line of the shell.

[0017] Preferably, the shell further comprises a second outlet, wherein the second outlet and the second inlet are arranged on both sides of the center line of the shell, and the second outlet is used for discharging the catalyst and the ligand.

[0018] Preferably, the device further comprises a stirrer, and the stirrer is arranged in the second chamber.

[0019] Compared with the prior art, the reactor for preparing isononanal by hydroformylation of isooctene according to the embodiment of the present invention has the following beneficial effects: a polytetrafluoroethylene filter membrane divides the inner cavity of a shell into a first chamber and a second chamber that are interconnected. When preparing isononanal, isooctene as a raw material enters the shell through the first inlet, first enters the first chamber, and then enters the second chamber through the polytetrafluoroethylene filter membrane. Synthesis gas enters the shell through the air inlet, passes through the polytetrafluoroethylene filter membrane, and fills the entire inner cavity. Catalyst and ligand enter the second chamber through the second inlet. The catalyst and ligand cannot pass through the polytetrafluoroethylene filter membrane and can only catalyze the reaction in the second chamber. The finished product without catalyst and ligand passes through the polytetrafluoroethylene in the second chamber and is discharged through the first outlet on the cavity wall of the first chamber. When isooctene enters the second chamber through the first chamber, the polytetrafluoroethylene filter membrane can be backwashed, so that the catalyst and ligand attached to it return to the second chamber, and the polytetrafluoroethylene filter membrane is not easily clogged. This not only reduces the loss of catalyst and ligand, but also extends the service life of the polytetrafluoroethylene filter membrane, ensuring the smooth preparation of isononanal. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic structural diagram of a reactor for preparing isononanal by hydroformylation of isooctene according to the present invention;

[0021] Figure 2 The utility model is a schematic diagram of the internal structure of a reactor for preparing isononanal by hydroformylation of isooctene.

[0022] In the figure, 1. shell, 11. first chamber, 12. second chamber, 2. polytetrafluoroethylene filter membrane, 3. first inlet, 4. first outlet, 5. second inlet, 6. second outlet, 7. air inlet, 8. exhaust port, 9. agitator. DETAILED DESCRIPTION

[0023] The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0024] A preferred embodiment of a reactor for preparing isononanal by hydroformylation of isooctene according to the present invention is as follows: Figure 1 and Figure 2 As shown, the reactor for preparing isononanal by hydroformylation of isooctene includes a shell 1, a polytetrafluoroethylene filter membrane 2, a first inlet 3, a first outlet 4, a second inlet 5 and an air inlet 7. The shell 1 as a whole is a cylindrical reactor structure, and the center line of the shell 1 is arranged horizontally to form a horizontal reactor. The polytetrafluoroethylene filter membrane 2, the first inlet 3, the first outlet 4, the second inlet 5 and the air inlet 7 are all assembled on the shell 1.

[0025] The housing 1 has an inner cavity, and a polytetrafluoroethylene (PTFE) filter membrane 2 is disposed within the inner cavity. The PTFE filter membrane 2 divides the inner cavity into a first chamber 11 and a second chamber 12 along the centerline of the housing 1. The dimensions of the PTFE filter membrane 2 are identical to the inner diameter of the housing 1. The first chamber 11 and the second chamber 12 are interconnected via the PTFE filter membrane 2. The rhodium catalyst and the macromolecular ligand cannot pass through the PTFE filter membrane 2, while the reaction raw material isooctene and the product isononanal can pass through the PTFE filter membrane 2, separating the catalytic system from the reaction products and raw materials. This ensures that the rhodium catalyst and the macromolecular phosphine ligand are not lost and can be recycled until their activity is lost.

[0026] First inlet 3 is arranged on the wall of first chamber 11 and communicates with first chamber 11. First inlet 3 allows isooctene, the raw material, to enter first chamber 11. After entering first chamber 11, isooctene can pass through polytetrafluoroethylene filter membrane 2 and enter second chamber 12. After each reaction, adding material through first inlet 3 reversely flushes polytetrafluoroethylene filter membrane 2, creating a solution with uniform catalyst and ligand concentrations, preventing localized excessive concentrations of the catalyst and ligand.

[0027] The first outlet 4 is arranged on the cavity wall of the first chamber 11, and the first outlet 4 is connected to the first chamber 11. The first outlet 4 is used to discharge the prepared isononanal, raw material isooctene and other small molecular compounds and enter the next stage for distillation. The raw material isooctene separated by distillation can be returned and enter the reactor through the first inlet 3 to continue the reaction.

[0028] A second inlet 5 is disposed on the wall of the second chamber 12. The second inlet 5 allows the catalyst and ligand to enter the housing 1. Prior to the first reaction, the catalyst and ligand are prepared as an isooctene solution and introduced into the second chamber 12 through the second inlet 5. If the catalytic effect is poor during the reaction, additional catalyst and ligand can be added at any time.

[0029] The second inlet 5 and the first outlet 4 are arranged in different chambers. After the reaction is completed, the multi-layer polytetrafluoroethylene filter membrane 2 effectively blocks the passage of the rhodium catalyst and the macromolecular ligand. The rhodium catalyst and the macromolecular ligand can only move in the second chamber 12. The reaction raw material isooctene and the product isononanal can pass through the polytetrafluoroethylene filter membrane 2 and enter the first chamber 11 from the second chamber 12, avoiding the loss of the rhodium catalyst and the macromolecular ligand.

[0030] An air inlet 7 is located on the outside of the housing 1 and communicates with the inner cavity. This inlet is used to introduce syngas for the hydroformylation reaction into the housing 1. In this embodiment, the syngas comprises hydrogen and carbon monoxide, with a molar ratio of 1-1.2. When the reactor liquid level is above the set point, syngas is added at a constant rate to the desired pressure. If necessary, syngas can be added at varying ratios through the air inlet 7 at any time during the reaction.

[0031] When preparing isononanal in this reactor, isooctene, as a raw material, enters the shell 1 through the first inlet 3, first enters the first chamber 11, and then enters the second chamber 12 through the polytetrafluoroethylene filter membrane 2. Synthesis gas enters the shell 1 through the air inlet 7, passes through the polytetrafluoroethylene filter membrane 2 and fills the entire inner cavity. The catalyst and ligand enter the second chamber 12 through the second inlet 5. The catalyst and ligand cannot pass through the polytetrafluoroethylene filter membrane 2 and can only catalyze the reaction in the second chamber 12. The finished product without the catalyst and ligand passes through the polytetrafluoroethylene from the second chamber 12 and is discharged through the first outlet 4 on the cavity wall of the first chamber 11. When isooctene enters the second chamber 12 through the first chamber 11, it can backwash the polytetrafluoroethylene filter membrane 2, so that the catalyst and ligand attached to it return to the second chamber 12, and it is not easy to clog the polytetrafluoroethylene filter membrane 2, thereby reducing the loss of the catalyst and ligand and extending the service life of the polytetrafluoroethylene filter membrane 2, thereby ensuring the smooth preparation of isononanal.

[0032] Preferably, the first inlet 3 and the first outlet 4 are arranged symmetrically with the center line of the housing 1 as an axis.

[0033] The first inlet 3 and the first outlet 4 are arranged on both sides of the housing 1, increasing the distance between the first inlet 3 and the first outlet 4. When preparing isononanal, the housing 1 is a horizontal structure, the first outlet 4 can be arranged at the bottom of the housing 1, and the first inlet 3 is arranged at the top of the housing 1, which facilitates the entry of raw materials and the discharge of products.

[0034] Preferably, the polytetrafluoroethylene filter membrane 2 has at least two groups, and each group of polytetrafluoroethylene filter membrane 2 is arranged in a stacking manner along the center line direction of the shell 1.

[0035] The polytetrafluoroethylene filter membrane 2 is arranged in multiple groups, and the multiple groups of polytetrafluoroethylene filter membrane 2 can well block the passage of rhodium catalyst and macromolecular ligand, thereby improving the filtering efficiency. In the embodiment, the polytetrafluoroethylene filter membrane has three groups in total.

[0036] Preferably, the gas inlet 7 is arranged on the cavity wall of the first cavity 11, and the gas inlet 7 is located on the center line of the shell 1.

[0037] The gas inlet 7 is arranged on the center line of the shell 1 and close to the set height of the liquid in the shell 1. After the synthesis gas enters the first cavity 11 from the gas inlet 7, the synthesis gas can diffuse upwards, thereby discharging the gas in the first cavity 11, achieving the effect of discharging air, and forming a good preparation environment.

[0038] Preferably, the gas outlet 8 is arranged on the cavity wall of the second cavity 12, and the direction of the gas outlet 8 is perpendicular to the center line of the shell 1.

[0039] The gas outlet 8 is arranged on the cavity wall of the second cavity 12. After the reaction is completed, the unreacted gas in the shell 1 can be discharged through the gas outlet 8, the inner cavity of the shell 1 is depressurized to normal pressure, and the toxic synthesis gas is discharged. In the embodiment, the gas outlet 8 is arranged at the top of the shell 1, so that the synthesis gas can be easily discharged by floating.

[0040] Preferably, the second outlet 6 is arranged on both sides of the center line of the shell 4 together with the second inlet 5, and the second outlet 6 is used for discharging the catalyst and the ligand.

[0041] The second outlet 6 and the second inlet 5 are arranged on both sides of the center line of the shell 4. In the preparation of isononyl aldehyde, the second inlet 5 is located at the top of the horizontal reactor, and the second outlet 6 is located at the bottom of the horizontal reactor. If the effect of the catalyst and the ligand is not satisfactory after a long time of reaction, the previous catalyst and ligand and the macromolecular compounds generated during the reaction can be discharged from the second outlet 6.

[0042] Preferably, the stirrer 9 is arranged in the second cavity 12.

[0043] The stirrer 9 is arranged in the second cavity 12, so that the raw materials and the catalyst in the second cavity 12 can be stirred to form a solution with uniform concentration, thereby avoiding local over-concentration and accelerating the reaction rate.

[0044] The working process of the reactor for preparing isononyl aldehyde by hydroformylation of isooctene according to the first embodiment of the reactor for preparing isononyl aldehyde by hydroformylation of isooctene is as follows.

[0045] First reaction: Clean the reactor, dry it, introduce nitrogen through inlet 7, pressurize it to 5 MPa, maintain the pressure for 24 hours, and replace the atmosphere with synthesis gas through inlet 7 until the oxygen content is below 5 ppm. Add 3.54 kg of isooctene (5 L) through first inlet 3, and a solution of isooctene composed of 3.54 g (0.1% wt) of rhodium catalyst and 6.72 g of phosphine ligand (equimolar amounts) through second inlet 5. Add synthesis gas through inlet 7 until the reaction pressure reaches 3 MPa. Stir using a stirrer 9, raise the temperature to 100°C, react for 4 hours, and then cool to room temperature. Open exhaust 8 to release the pressure, then introduce nitrogen three times, and open first outlet 4 to discharge the reaction mixture. The discharged reaction liquid is tested to be free of rhodium metal and phosphine ligand. The reaction liquid is then transferred to a distillation reactor, and the separated raw isooctene can be returned for further reaction. GC analysis shows an isooctene conversion of 93% and a selectivity for isononanal of 95%.

[0046] Second and subsequent reactions: Synthesis gas is used to displace the gas in the reactor through inlet 7 until the oxygen content is below 5 ppm. Stirring is initiated using stirrer 9. Raw isooctenes are added through first inlet 3 to reversely flush the polytetrafluoroethylene filter membrane 2 until the desired liquid level is reached. Synthesis gas is introduced through inlet 7 to a reaction pressure of 3 MPa. The temperature is raised to 100°C and allowed to react for 4 hours before cooling to room temperature. Exhaust 8 is opened for pressure relief, followed by nitrogen replacement three times. The first outlet 4 is opened for discharge. The discharged reaction liquid is tested to be free of rhodium metal and phosphine ligands. The reaction liquid is then transferred to a distillation reactor, where the separated raw isooctenes can be returned for further reaction.

[0047] The process from the third to the fifth time is the same as the second time.

[0048] The results of 5 consecutive reactions are shown in the following table:

[0049] Number of reactions Conversion rate (%) Selectivity (%) first 93.2 95.8 Second time 92.1 94.5 The third time 93.3 93.9 Fourth time 91.2 95.1 Fifth 91.4 93.6

[0050] Table 1

[0051] In summary, the reactor for preparing isononyl aldehyde by hydroformylation of isooctene provided by the embodiments of the present application has a polytetrafluoroethylene filter film that divides the inner cavity of the shell into a first chamber and a second chamber that are in communication with each other, and when preparing isononyl aldehyde, isooctene as a raw material enters the shell through the first inlet, first enters the first chamber, and then enters the second chamber through the polytetrafluoroethylene filter film, synthesis gas enters the shell through the gas inlet, fills the entire inner cavity through the polytetrafluoroethylene filter film, the catalyst and the ligand enter the second chamber through the second inlet, the catalyst and the ligand cannot pass through the polytetrafluoroethylene filter film, and can only catalyze the reaction in the second chamber, the finished product without the catalyst and the ligand is discharged through the first outlet on the cavity wall of the first chamber after passing through the polytetrafluoroethylene in the second chamber, and when isooctene enters the second chamber through the first chamber, the polytetrafluoroethylene filter film can be back-flushed, so that the catalyst and the ligand attached to the polytetrafluoroethylene filter film return to the second chamber, the polytetrafluoroethylene filter film is not prone to be blocked, the loss of the catalyst and the ligand is reduced, the service life of the polytetrafluoroethylene filter film is prolonged, and the smooth preparation of isononyl aldehyde is ensured.

[0052] The above only describes preferred embodiments of the present application, and it should be noted that, for those skilled in the art, without departing from the technical principles of the present application, a number of improvements and replacements can be made, and these improvements and replacements should also be considered as the protection scope of the present application.

Claims

1. A reactor for preparing isononanal by hydroformylation of isooctene, characterized in that: It comprises a housing (1) having an inner cavity, wherein a polytetrafluoroethylene filter membrane (2) is arranged in the inner cavity, and the polytetrafluoroethylene filter membrane (2) divides the inner cavity into a first chamber (11) and a second chamber (12) which are interconnected; A first inlet (3) for isooctene to enter and a first outlet (4) for finished product to be discharged are provided on the wall of the first chamber (11), the first inlet (3) and the first outlet (4) both being in communication with the first chamber (11), and a second inlet (5) for catalyst and ligand to enter is also provided on the wall of the second chamber (12); The shell (1) is also provided with an air inlet (7) communicating with the inner cavity for conveying synthesis gas.

2. The reactor for preparing isononanal by hydroformylation of isooctene according to claim 1, characterized in that: The first inlet (3) and the first outlet (4) are arranged symmetrically with the center line of the housing (1) as an axis.

3. The reactor for preparing isononanal by hydroformylation of isooctene according to claim 1, characterized in that: There are at least two groups of polytetrafluoroethylene filter membranes (2), and each group of polytetrafluoroethylene filter membranes (2) is stacked and arranged along the center line direction of the shell (1).

4. The reactor for preparing isononanal by hydroformylation of isooctene according to claim 1, characterized in that: The air inlet (7) is arranged on the cavity wall of the first chamber (11), and the air inlet (7) is located on the center line of the shell (1).

5. The reactor for preparing isononanal by hydroformylation of isooctene according to claim 4, characterized in that: It also includes an exhaust port (8), which is arranged on the cavity wall of the second cavity (12), and the direction of the exhaust port (8) is perpendicular to the center line of the shell (1).

6. The reactor for preparing isononanal by hydroformylation of isooctene according to claim 1, characterized in that: The housing further comprises a second outlet (6), wherein the second outlet (6) and the second inlet (5) are arranged on both sides of the center line of the housing (1), and the second outlet (6) is used for discharging the catalyst and the ligand.

7. The reactor for preparing isononanal by hydroformylation of isooctene according to claim 1, characterized in that: The invention also comprises an agitator (9), wherein the agitator (9) is arranged in the second chamber (12).

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