Aldehyde liquid phase hydrogenation reaction system

Abstract

The invention discloses a reaction system for liquid-phase hydrogenation of aldehydes. The reaction system comprises a pre-hydrogenation reactor, a main hydrogenation reactor and a gas-liquid separator. The pre-hydrogenation reactor is provided with an inlet for adding an aldehyde liquid phase and hydrogen, and a plurality of first catalytic bed layers are arranged in the pre-hydrogenation reactor at intervals in the vertical direction. The main hydrogenation reactor is communicated with an outlet of the pre-hydrogenation reactor, and a plurality of second catalytic bed layers are arranged in the main hydrogenation reactor at intervals in the vertical direction. And the gas-liquid separator is communicated with an outlet of the main hydrogenation reactor and is used for carrying out gas-liquid separation on a product output by the main hydrogenation reactor. The aldehydes liquid phase realizes two hydrogenation reactions through the pre-hydrogenation reactor and the main hydrogenation reactor, and the first bubble crushing unit is arranged in the main hydrogenation reactor and is used for crushing and dispersing reaction materials, so that the reaction materials can be crushed and dispersed into microbubbles, and the aldehydes liquid phase and hydrogen are fully mixed; and the mass transfer area between the gas phase and the liquid phase is increased, so that the conversion rate of aldehydes and the utilization rate of hydrogen are improved.

Description

Technical Field

[0001] The present application belongs to the technical field of liquid-phase hydrogenation of aldehydes, and specifically relates to a reaction system for liquid-phase hydrogenation of aldehydes. Background Art

[0002] Aldehyde hydrogenation is a crucial conversion process in the chemical industry, widely used in pharmaceuticals, fragrance manufacturing, and fine chemicals. Examples include liquid-phase hydrogenation of butyraldehyde to produce butanol or butane, and liquid-phase hydrogenation of octenal to produce octanol. Liquid-phase hydrogenation of butyraldehyde involves liquefying butyraldehyde gas and then mixing it with hydrogen. However, during the contact between the butyraldehyde liquid phase and hydrogen, the formation of numerous and large hydrogen bubbles hinders adequate mixing of the gas and liquid phases.

[0003] In related technologies, in order to ensure sufficient mixing of the gas and liquid phases, the reaction temperature usually needs to be controlled between 150°C and 250°C, and the reaction pressure may be as high as 5MPa to 10MPa. Such high temperature and high pressure conditions seriously affect the raw material conversion rate and hydrogen utilization rate, and reduce the reaction efficiency of the reaction between butyraldehyde molecules and hydrogen. Summary of the Invention

[0004] In order to solve the technical problem in the related art that high temperature and high pressure reaction conditions seriously affect the raw material conversion rate and hydrogen utilization rate, thereby reducing the reaction efficiency of the reaction between butyraldehyde molecules and hydrogen, the present application provides a reaction system for liquid-phase hydrogenation of aldehydes, the reaction system for liquid-phase hydrogenation of aldehydes comprising:

[0005] A pre-hydrogenation reactor is provided with an aldehyde liquid phase inlet and a hydrogen inlet, wherein multiple first catalytic beds are vertically spaced apart in the pre-hydrogenation reactor;

[0006] A main hydrogenation reactor is connected to the outlet of the pre-hydrogenation reactor, wherein multiple layers of second catalytic beds are vertically spaced apart in the main hydrogenation reactor, and a first bubble crushing unit is provided in the main hydrogenation reactor for crushing and dispersing the reaction materials;

[0007] The gas-liquid separator is connected to the outlet of the main hydrogenation reactor and is used for performing gas-liquid separation on the product output from the main hydrogenation reactor.

[0008] In some embodiments, the first bubble breaking unit comprises:

[0009] a first bubble breaker, arranged above the second catalytic bed layer on the top layer;

[0010] The second bubble breaker is arranged at the bottom of the main hydrogenation reactor and is located below the second catalytic bed layer at the bottom layer.

[0011] In some embodiments, a stirring assembly is provided between the second catalytic bed layer at the bottom layer in the main hydrogenation reactor and the second bubble breaker.

[0012] In some embodiments, the stirring assembly comprises:

[0013] a vertical stirring paddle connected to the side wall of the main hydrogenation reactor;

[0014] The horizontal stirring paddle is connected to the vertical stirring paddle and is located below the vertical stirring paddle. The horizontal stirring paddle is arc-shaped and its bending direction is upward.

[0015] In some embodiments, a distribution plate is provided in the main hydrogenation reactor, and the distribution plate is provided above the outlet of the second bubble breaker.

[0016] In some embodiments, a diffuser is provided in the main hydrogenation reactor. The diffuser is disposed below the second bubble breaker and connected to the feed port of the main hydrogenation reactor.

[0017] In some embodiments, a defoaming tray is provided in the main hydrogenation reactor, and the defoaming tray is located above the first bubble breaking unit.

[0018] In some embodiments, a cleaning assembly is provided above the defoaming tray, and the cleaning assembly includes:

[0019] A rotating block is located above the defoaming plate and is coaxially rotatably connected to the defoaming plate;

[0020] A brush is connected to the rotating block and can contact the upper surface of the defoaming disc.

[0021] In some embodiments, a second bubble crushing unit is provided in the pre-hydrogenation reactor, and the second bubble crushing unit includes a plurality of built-in bubble breakers. The built-in bubble breakers are provided corresponding to the first catalytic bed and are located below the first catalytic bed.

[0022] In some embodiments, at least two of the plurality of built-in bubble breakers are arranged on the same vertical line.

[0023] In some embodiments, a condenser is provided between the pre-hydrogenation reactor and the main hydrogenation reactor.

[0024] In some embodiments, the reaction system for liquid-phase hydrogenation of aldehydes further comprises:

[0025] A raw material buffer tank and a mixed aldehyde separation unit, wherein the raw material buffer tank is connected to the aldehyde liquid phase inlet of the pre-hydrogenation reactor through the mixed aldehyde separation unit;

[0026] a hydrogen buffer tank connected with a hydrogen inlet of the pre-hydrogenation reactor.

[0027] In some embodiments, a hydrogen filter is arranged between the hydrogen buffer tank and the pre-hydrogenation reactor.

[0028] In some embodiments, the aldehyde liquid-phase hydrogenation reaction system further comprises:

[0029] a third bubble breaker group located outside the pre-hydrogenation reactor, the mixed aldehyde separation unit and the hydrogen buffer tank are respectively connected with an inlet of the third bubble breaker group, and an outlet of the third bubble breaker group is connected with an aldehyde liquid-phase inlet and a hydrogen inlet of the pre-hydrogenation reactor.

[0030] In some embodiments, a liquid-phase feeding pump is arranged between the pre-hydrogenation reactor and the third bubble breaker group.

[0031] In some embodiments, the aldehyde liquid-phase hydrogenation reaction system further comprises:

[0032] an alcohol cooler, one end of which is connected with the gas-liquid separator, and the other end of which is connected with the raw material buffer tank.

[0033] In some embodiments, the aldehyde liquid-phase hydrogenation reaction system further comprises:

[0034] a low-division gas-liquid separator connected with a top end of the gas-liquid separator.

[0035] In some embodiments, a low-division gas cooler is arranged between the low-division gas-liquid separator and the gas-liquid separator.

[0036] In some embodiments, the aldehyde liquid-phase hydrogenation reaction system further comprises:

[0037] a rectification system connected with the gas-liquid separator and the low-division gas-liquid separator.

[0038] According to the reaction system for liquid-phase hydrogenation of aldehydes provided in one or more embodiments of the present application, the reaction system for liquid-phase hydrogenation of aldehydes includes a pre-hydrogenation reactor, a main hydrogenation reactor and a gas-liquid separator. The pre-hydrogenation reactor is provided with an inlet for adding aldehyde liquid phase and hydrogen, and multiple layers of first catalytic beds are arranged at intervals along the vertical direction in the pre-hydrogenation reactor. The main hydrogenation reactor is connected to the outlet of the pre-hydrogenation reactor, and multiple layers of second catalytic beds are arranged at intervals along the vertical direction in the main hydrogenation reactor. The gas-liquid separator is connected to the outlet of the main hydrogenation reactor and is used to perform gas-liquid separation on the product output by the main hydrogenation reactor. Since the aldehyde liquid phase undergoes two hydrogenation reactions through the pre-hydrogenation reactor and the main hydrogenation reactor, the reaction rate of the aldehyde liquid phase and hydrogen can be increased, and the conversion rate of the aldehyde liquid phase and the utilization rate of hydrogen can be increased. The first bubble crushing unit is arranged in the main hydrogenation reactor to crush and disperse the reaction materials. It can crush and disperse the reaction raw materials into microbubbles, so that the aldehyde liquid phase and hydrogen are fully mixed, the mass transfer area between the gas and liquid phases is increased, the reaction between the aldehyde liquid phase and hydrogen is promoted, and the reaction rate between the aldehyde liquid phase and hydrogen is increased, thereby improving the conversion rate of aldehydes and the utilization rate of hydrogen. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 Schematic diagram of the structure of the reaction system for liquid-phase hydrogenation of aldehydes in one or more embodiments of the present application.

[0040] Description of reference numerals:

[0041] 1. Pre-hydrogenation reactor; 101. Second bubble breaker unit; 1011. Third bubble breaker; 1012. Fourth bubble breaker; 1013. Fifth bubble breaker; 1014. Sixth bubble breaker; 2. Main hydrogenation reactor; 201. First bubble breaker unit; 2011. First bubble breaker; 2012. Second bubble breaker; 3. Gas-liquid separator; 4. Distillation system; 51. First catalytic bed; 52. Second catalytic bed; 6. Agitation assembly; 601. Horizontal agitator; 602, vertical stirring paddle; 700, defoaming plate; 701, rotating block; 702, brush; 8, distribution plate; 9, diffuser; 10, condenser; 11, third bubble breaker unit; 111, seventh bubble breaker; 112, eighth bubble breaker; 113, connecting pipe; 114, liquid feed pump; 12, mixed aldehyde separation unit; 13, hydrogen buffer tank; 14, alcohol cooler; 15, low-gas and liquid separator tank; 16, raw material buffer tank; 17, hydrogen filter; 18, low-gas cooler. DETAILED DESCRIPTION

[0042] In order to enable those skilled in the art to understand the present application more clearly, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of this application.

[0043] Aldehyde hydrogenation is an important conversion process in the chemical industry, widely used in pharmaceuticals, fragrance manufacturing, and fine chemicals. Examples include liquid-phase hydrogenation of butyraldehyde to butanol or butane, and liquid-phase hydrogenation of octenal to octanol.

[0044] During the liquid-phase hydrogenation reaction of butyraldehyde, butyraldehyde reacts with hydrogen in the presence of a catalyst to convert into butanol or butane. Butanol, as an important organic solvent and chemical intermediate, has important applications in many chemical synthesis processes. The equation for the reaction of butyraldehyde with hydrogen in the liquid phase is:

[0045] C4H8O+H2→C4H9OH;

[0046] C4H8O+2H2→C4H 10 +H2O.

[0047] Butyraldehyde liquid phase hydrogenation is carried out by liquefying butyraldehyde gas and then mixing it with hydrogen. However, during the contact process between the butyraldehyde liquid phase and hydrogen, the hydrogen bubbles are numerous and large, which affects the full mixing of the gas and liquid phases.

[0048] In related technologies, in order to ensure sufficient mixing of the gas and liquid phases, the reaction temperature usually needs to be controlled between 150°C and 250°C, and the reaction pressure may be as high as 5MPa to 10MPa. Such high temperature and high pressure conditions seriously affect the raw material conversion rate and hydrogen utilization rate, and reduce the reaction efficiency of the reaction between butyraldehyde molecules and hydrogen.

[0049] In order to solve the technical problem in the related art that high temperature and high pressure reaction conditions seriously affect the raw material conversion rate and hydrogen utilization rate, and reduce the reaction efficiency of the reaction between butyraldehyde molecules and hydrogen, the present application provides a reaction system for liquid phase hydrogenation of aldehydes.

[0050] Example 1

[0051] The reaction system for liquid-phase hydrogenation of aldehydes includes a pre-hydrogenation reactor 1, a main hydrogenation reactor 2, and a gas-liquid separator 3, which are connected in sequence. The pre-hydrogenation reactor 1 is equipped with an aldehyde liquid phase inlet for adding the aldehyde liquid phase and a hydrogen inlet for adding hydrogen. Multiple first catalytic beds 51 are vertically spaced apart within the pre-hydrogenation reactor 1. The reaction products discharged from the top of the pre-hydrogenation reactor 1 are passed into the main hydrogenation reactor 2 for reaction. The main hydrogenation reactor 2 is connected to the outlet of the pre-hydrogenation reactor 1 and is vertically spaced apart within the main hydrogenation reactor 2. The gas-liquid separator 3 is connected to the outlet of the main hydrogenation reactor 2 and is used to separate the gas-liquid output of the main hydrogenation reactor 2 into alcohol products. Because the aldehyde liquid phase undergoes two hydrogenation reactions through the pre-hydrogenation reactor 1 and the main hydrogenation reactor 2, the structure is simple and can increase the reaction rate of the aldehyde liquid phase and hydrogen under the catalytic action of the first catalytic bed 51 and the second catalytic bed 52, thereby improving the conversion rate of the aldehyde liquid phase and the utilization rate of the hydrogen.

[0052] A first bubble crushing unit 201 is provided in the main hydrogenation reactor 2. The first bubble crushing unit 201 is used to crush and disperse the reaction materials (aldehyde liquid phase and hydrogen). It can crush and disperse the reaction raw materials into microbubbles, so that the aldehyde liquid phase and hydrogen are fully mixed, the mass transfer area between the gas and liquid phases is increased, the reaction between the aldehyde liquid phase and hydrogen is promoted, and the reaction rate between the aldehyde liquid phase and hydrogen is increased, thereby improving the conversion rate of aldehydes and the utilization rate of hydrogen.

[0053] Incorporating bubble collapse technology into the aldehyde liquid-phase hydrogenation process shortens reaction time. The hydrogenation reaction temperature is 60°C to 120°C, and the reaction pressure is 0.5 MPa to 2 MPa. This reduces reaction temperature and pressure, resulting in milder operating conditions, lower energy consumption, and significantly lowers costs. This effectively improves aldehyde liquid-phase conversion, product yield, and hydrogen utilization. The process is simple to operate, enhancing the operability of the aldehyde liquid-phase hydrogenation reaction.

[0054] The first bubble crusher unit 201 comprises a first bubble crusher 2011 and a second bubble crusher 2012. The first bubble crusher 2011 is arranged above the second catalytic bed 52 in the top layer, and the second bubble crusher 2012 is arranged at the bottom in the main hydrogenation reactor 2, and is positioned at below the second catalytic bed 52 in bottom. Like this, the first bubble crusher 2011 is arranged at the top of the main hydrogenation reactor 2, and by passing hydrogen at the top and carrying out crushing dispersion, the aldehyde liquid phase reaction of unreacted completion can be improved, the conversion rate of aldehyde liquid phase and the utilization rate of hydrogen. The second bubble crusher 2012 is arranged at the bottom of the main hydrogenation reactor 2, and the second bubble crusher 2012 carries out crushing dispersion to the reaction raw materials entering the main hydrogenation reactor 2, and advances reaction raw materials to the top of the main hydrogenation reactor 2. The first bubble breaker 2011 and the second bubble breaker 2012 can break up the aldehyde liquid phase and hydrogen into microbubbles, so that the aldehyde liquid phase and hydrogen are fully mixed, the mass transfer area between the gas and liquid phases is increased, and the reaction rate between the aldehyde liquid phase and hydrogen is increased.

[0055] It should be noted that the first bubble breaker 2011 can be configured with different structures and forms. The specific working principles can be found in patents such as CN201610641119.6, CN201610641251.7, CN201710766435.0, CN106187660, CN105903425A, CN205833127U, and CN207581700U, which are not described in detail in this application. The first bubble breaker 2011 can also be referred to as a micron bubble generator, a micro-interface generator, etc. The working principle of the second bubble breaker 2012 is the same as that of the first bubble breaker 2011 and is not described in detail here.

[0056] A stirring assembly 6 is provided between the second catalytic bed 52 of the bottom layer in the main hydrogenation reactor 2 and the second bubble breaker 2012. The first bubble crushing unit 201 is used in conjunction with the stirring assembly 6 to crush, disperse and stir the reaction raw materials entering the main hydrogenation reactor 2. Specifically, the stirring assembly 6 includes a vertical stirring paddle 602 and a horizontal stirring paddle 601. The vertical stirring paddle 602 is located in the main hydrogenation reactor 2 and is connected to the side wall of the main hydrogenation reactor 2. The horizontal stirring paddle 601 is connected to the vertical stirring paddle and is located below the vertical stirring paddle. The horizontal stirring paddle is in an arc shape and its bending direction is upward. Such an arrangement can transmit the gas-liquid mixture coming out of the second bubble breaker 2012 upward. At the same time, when used in conjunction with the vertical stirring paddle 602, the mixed raw materials moving upward in the main hydrogenation reactor 2 can be stirred, thereby improving the conversion rate of hydrogen and raw materials.

[0057] In order to make the gas-liquid mixture of aldehyde liquid phase and hydrogen uniformly distributed in the main hydrogenation reactor 2, the main hydrogenation reactor 2 is provided with a distribution plate 8, which is arranged below the horizontal stirring paddle 601 and above the outlet of the second bubble breaker 2012. Through the arrangement of the distribution plate 8, the uniformity of the gas-liquid mixture in the main hydrogenation reactor 2 is improved, thereby promoting the reaction between the aldehyde liquid phase and hydrogen and improving the conversion rate of aldehydes and the utilization rate of hydrogen.

[0058] The main hydrogenation reactor 2 is provided with a diffuser 9, which is arranged below the second bubble breaker 2012 and connected with the feed inlet of the main hydrogenation reactor 2. Through the arrangement of the diffuser 9, the flow rate of the feed can be controlled, the turbulent flow can be reduced, and fluid separation can be prevented.

[0059] The main hydrogenation reactor 2 is provided with a defoaming plate 700, which is arranged above the first bubble breaker 2011 and inside the main hydrogenation reactor 2. The defoaming plate 700 is arranged in the gas rising path, and the gas can move upward through the defoaming plate 700. The defoaming plate 700 can remove liquid droplets from the gas to prevent liquid from flowing out of the main hydrogenation reactor 2 with the gas. A cleaning assembly is arranged above the defoaming plate 700, which includes a rotating block 701 and a brush 702. The rotating block 701 is coaxially connected with the defoaming plate 700 and arranged above the defoaming plate 700. The brush 702 is connected with the rotating block 701 and can contact the upper surface of the defoaming plate 700. The brush 702 can be arranged in two and connected with the two sides of the rotating block 701. The brush 702 contacts the upper surface of the defoaming plate 700, which can effectively remove the liquid droplets accumulated on the surface of the defoaming plate 700 and prevent the re-accumulation of liquid droplets. The brush 702 can prevent the defoaming plate 700 from being blocked and prevent the reaction material from overflowing out of the main hydrogenation reactor 2 with the gas, thereby preventing material loss. It should be noted that the number of brushes 702 can be arranged according to actual needs, and the present application is not limited.

[0060] In order to improve the breaking and dispersing degree of the aldehyde liquid phase and hydrogen, the pre-hydrogenation reactor 1 is provided with a second bubble breaking machine group 101, which can preliminarily break and disperse the aldehyde liquid phase and hydrogen, thereby improving the conversion rate of the aldehyde liquid phase and the utilization rate of hydrogen. The second bubble breaking machine group 101 includes a plurality of built-in bubble breakers, which are arranged correspondingly with the first catalytic bed 51 and below the first catalytic bed 51.

[0061] The plurality of built-in bubble breakers include a third bubble breaker 1011, a fourth bubble breaker 1012, a fifth bubble breaker 1013, and a sixth bubble breaker 1014. The third bubble breaker 1011, the fourth bubble breaker 1012, the fifth bubble breaker 1013, and the sixth bubble breaker 1014 correspond to the first catalytic bed 51 and are located below the first catalytic bed 51. At least two of the third bubble breaker 1011, the fourth bubble breaker 1012, the fifth bubble breaker 1013, and the sixth bubble breaker 1014 are arranged on the same vertical line. By arranging the plurality of built-in bubble breakers in the second bubble breaker unit 101 on the same line, the gas can be moved from bottom to top. On the other hand, the interfacial mass transfer area between the aldehyde liquid phase and the hydrogen can be increased, thereby improving the reaction efficiency between the aldehyde liquid phase and the hydrogen, thereby improving the conversion rate of the aldehyde liquid phase and the utilization rate of the hydrogen.

[0062] It should be noted that the working principles of the third bubble breaker 1011, the fourth bubble breaker 1012, the fifth bubble breaker 1013 and the sixth bubble breaker 1014 are the same as those of the first bubble breaker 2011, and are not described in detail here.

[0063] A condenser 10 is provided between the pre-hydrogenation reactor 1 and the main hydrogenation reactor 2 . The condenser 10 reduces the temperature of the product coming out of the pre-hydrogenation reactor 1 through a cooling medium to reach the reaction temperature of the main hydrogenation reactor 2 .

[0064] The reaction system for liquid-phase hydrogenation of aldehydes also includes a raw material buffer tank 16, a mixed aldehyde separation unit 12, and a hydrogen buffer tank 13. The raw material buffer tank 16 is connected to the aldehyde liquid phase inlet of the pre-hydrogenation reactor 1 through the mixed aldehyde separation unit 12. The mixed aldehyde separation unit 12 is connected to the raw material buffer tank 16 for separating the aldehyde liquid phase and providing the aldehyde liquid phase to the pre-hydrogenation reactor 1. The hydrogen buffer tank 13 is connected to the hydrogen inlet of the pre-hydrogenation reactor 1 for providing hydrogen to the pre-hydrogenation reactor 1. A hydrogen filter 17 is provided between the hydrogen buffer tank 13 and the pre-hydrogenation reactor 1. The hydrogen filter 17 can remove impurities in the hydrogen, reduce the production of by-products, and improve the purity and quality of the product.

[0065] The aldehyde liquid-phase hydrogenation reaction system also includes an alcohol cooler 14 and a low-fraction gas-liquid separator 15. One end of the alcohol cooler 14 is connected to the bottom end of the gas-liquid separator 3, and the other end is connected to the inlet of the raw material buffer tank 16. This cooler is used to cool the aldehyde liquid phase separated by the gas-liquid separator 3 before returning it to the reaction system, thereby fully utilizing the aldehyde liquid phase and improving its utilization rate.

[0066] Low-gas separator tank 15 is connected to the top of gas-liquid separator 3 to separate the low-gas fraction. A low-gas cooler 18 is located between tank 15 and gas-liquid separator 3 to cool the low-gas fraction to facilitate gas-liquid separation. Cooling and separating the low-gas fraction effectively recovers valuable components from the gas for reuse, while also minimizing environmental impact and contributing to environmental protection and sustainable development.

[0067] The bottom end of the low-gas-liquid separator 15 and the bottom of the gas-liquid separator 3 are respectively connected to the distillation system 4, which is used to transport the generated alcohol liquid to the distillation system 4. By setting up the distillation system 4, the purity of the alcohol product is improved to ensure the quality and performance of the product.

[0068] The reaction system for liquid-phase hydrogenation of aldehydes also includes a third bubble crushing unit 11, which is located outside the pre-hydrogenation reactor 1. The mixed aldehyde separation unit 12 and the hydrogen buffer tank 13 are respectively connected to the inlet of the third bubble crushing unit 11, and the outlet of the third bubble crushing unit 11 is connected to the feed port of the pre-hydrogenation reactor 1.

[0069] The third bubble breaker unit 11 includes a seventh bubble breaker 111 and an eighth bubble breaker 112. The seventh bubble breaker 111 is connected to the hydrogen buffer tank 13 via a hydrogen filter 17 and can break up and disperse hydrogen into hydrogen microbubbles. The eighth bubble breaker 112 is connected to the raw material buffer tank 16 via the mixed aldehyde separation unit 12 and can break up and disperse the aldehyde liquid phase into liquid microbubbles. The seventh bubble breaker 111 and the eighth bubble breaker 112 are connected by a connecting pipe 113, which increases the interfacial mass transfer area between the aldehyde liquid phase and the hydrogen, improves the reaction efficiency between the aldehyde liquid phase and the hydrogen, and thus improves the conversion rate of the aldehyde liquid phase and the utilization rate of the hydrogen.

[0070] A liquid phase feed pump 114 is provided between the pre-hydrogenation reactor 1 and the third bubble crushing unit 11 to increase the speed and convenience of conveying the gas-liquid mixture in the third bubble crushing unit 11 to the pre-hydrogenation reactor 1 .

[0071] Taking the liquid-phase hydrogenation of butyraldehyde as an example, the reaction process of the liquid-phase hydrogenation reaction system of aldehydes in this application is as follows: the butyraldehyde from the separation section is flow-regulated and enters the raw material buffer tank 16, the butanol from the gas-liquid separator 3 is condensed through the alcohol cooler 14 and circulated into the raw material buffer tank 16 as a raw material solvent, and the liquid butyraldehyde enters the third bubble crushing unit 11 through the raw material buffer tank 16 and then enters the pre-hydrogenation reactor 1.

[0072] Hydrogen is introduced from outside the device into a hydrogen buffer tank 13. A wire mesh demister is installed on top of the hydrogen buffer tank 13 to remove liquid droplets contained in the hydrogen. The hydrogen then passes through the hydrogen buffer tank 13 and into the compressor. After passing through the compressor, it enters the hydrogen filter 17, where it is filtered and passed into the pre-hydrogenation reactor 1, the first bubble crushing unit 201, the second bubble crushing unit 101, and the third bubble crushing unit 11. By connecting the hydrogen filter 17 to the first bubble crushing unit 201, the second bubble crushing unit 101, and the third bubble crushing unit 11, respectively, the high purity of the hydrogen is ensured and gas dispersion is optimized, thereby increasing the rate and selectivity of the hydrogen reaction and reducing side reactions.

[0073] Liquid butyraldehyde and hydrogen react in pre-hydrogenation reactor 1 and main hydrogenation reactor 2 before entering gas-liquid separator 3. Part of the liquid butanol separated by gas-liquid separator 3 enters distillation system 4 for separation as a product, while part is cooled in alcohol cooler 14 and circulated as a raw material solvent to raw material buffer tank 16.

[0074] Example 2

[0075] The difference between Example 2 and Example 1 is that the third bubble breaker 1011 , the fourth bubble breaker 1012 , the fifth bubble breaker 1013 and the sixth bubble breaker 1014 are not on the same vertical line.

[0076] Example 3

[0077] The difference between Example 3 and Example 1 is that the first bubble crushing unit 201 is not provided in the main hydrogenation reactor 2.

[0078] Example 4

[0079] The difference between Example 4 and Example 1 is that no stirring assembly 6 is provided in the main hydrogenation reactor 2 .

[0080] Comparative Example 1

[0081] The difference between Comparative Example 1 and Example 1 is that the third bubble crushing unit 11 is not provided.

[0082] Comparative Example 2

[0083] Comparative Example 2 differs from Example 1 in that the diffuser 9 is not provided.

[0084] Comparative Example 3

[0085] The difference between Comparative Example 3 and Example 1 is that the second bubble crushing unit 101 is not provided.

[0086] Comparative Example 4

[0087] Comparative Example 4 uses relevant technology to directly introduce liquid aldehydes and hydrogen into the hydrogenation reactor to carry out liquid-phase hydrogenation reaction of aldehydes.

[0088] Experimental Example 1: Liquid-phase butyraldehyde hydrogenation was performed using the reaction systems of Examples 1 to 4 and Comparative Examples 1 to 3. The specific experimental conditions were as follows: a butyraldehyde flow rate of 20,695 kg / h and a hydrogen flow rate of 850 kg / h. The reaction results are shown in Table 1 below:

[0089] Reaction temperature (℃) Reaction pressure (MPa) Butyraldehyde conversion rate (%) Butanol purity (%) Example 1 75 1.05 100 99.9 Example 2 82 1.22 100 99.1 Example 3 116 1.97 100 95.3 Example 4 98 1.69 100 96.5 Comparative Example 1 103 1.75 100 98.7 Comparative Example 2 95 1.58 100 98.2 Comparative Example 3 106 1.66 100 96.9 Related technologies 250 9.58 98 83.6

[0090] Table 1

[0091] The reaction temperature in Table 1 is the highest reaction temperature required during the reaction, and the reaction pressure is the highest reaction pressure required during the reaction.

[0092] In the related art, the reaction temperature for liquid-phase hydrogenation of butyraldehyde is 250°C and the reaction pressure is 9.58 MPa. As can be seen from Table 1, compared with the hydrogenation reactor in the related art, the reaction temperature and reaction pressure of each embodiment of the present application are significantly lower.

[0093] As can be seen from Table 1, Example 1 of the present application is the optimal embodiment. The reaction temperature of Example 1 is significantly lower than the reaction temperature of butyraldehyde liquid-phase hydrogenation in the related art. Under the premise that the reaction pressure is significantly reduced, there is still a good raw material conversion rate and product purity. At the same time, the butanol purity is significantly improved, which means that the setting mode of the stirring component 6 and the first bubble crushing unit 201 in Example 1 can achieve the optimal reaction effect. It can be seen that the reaction energy consumption of the reaction system of this embodiment is low, and the preparation effect of butanol is good.

[0094] The butanol concentration in Example 3 is lower than that in Example 1. This is because the first bubble crusher unit 201 is not provided in Comparative Example 3, which cannot fully crush and disperse the hydrogen and butanol in the main hydrogenation reactor 2, and will not be used in conjunction with the stirring assembly 6. It can be seen that in Example 1, the purity and conversion rate of butanol are improved and the reaction temperature and reaction pressure are reduced by setting the arrangement of the bubble crushers in the main hydrogenation reactor 2.

[0095] Experimental Example 2: The reaction systems of Examples 1 to 4 and Comparative Examples 1 to 3 were used to carry out liquid-phase hydrogenation of octenal. The specific experimental conditions were as follows: the flow rate of octenal was 26149 kg / h, and the flow rate of hydrogen was 1068 kg / h. The reaction results are shown in Table 2 below:

[0096]

[0097] Table 2

[0098] The reaction temperature in Table 2 is the highest reaction temperature required during the reaction, and the reaction pressure is the highest reaction pressure required during the reaction.

[0099] In the liquid phase hydrogenation of octenal in the related art, the reaction temperature is 245°C and the reaction pressure is 7.38 MPa. As can be seen from Table 1, compared with the hydrogenation reactor in the related art, the reaction temperature and reaction pressure of each embodiment of the present application are significantly lower.

[0100] As can be seen from Table 2, Example 1 of the present application is the optimal embodiment. The reaction temperature of Example 1 is significantly lower than the reaction temperature of octenal liquid-phase hydrogenation in the related art. Under the premise that the reaction pressure is significantly reduced, there is still a good raw material conversion rate and product purity. At the same time, the purity of octenol is significantly improved. This shows that the arrangement of the stirring assembly 6 and the first bubble crushing unit 201 in Example 1 can achieve the optimal reaction effect. It can be seen that the reaction energy consumption of the reaction system of this embodiment is low, and the preparation effect of octenol is good.

[0101] The octenol concentration in Example 3 is lower than that in Example 1. This is because the first bubble breaker unit 201 is not provided in Comparative Example 3, which cannot fully crush and disperse the hydrogen and octenol in the main hydrogenation reactor 2, and cannot be used in conjunction with the stirring assembly 6. It can be seen that in Example 1, the purity of octenol and the conversion rate of octenol are improved, and the reaction temperature and pressure are reduced by setting the arrangement of the bubble breaker in the main hydrogenation reactor 2.

[0102] In summary, compared with related technologies, the aldehyde liquid phase hydrogenation reaction system of the present application has low reaction temperature and reaction pressure, high conversion rate of aldehyde liquid phase and hydrogen, and high product purity, and is worthy of wide promotion and application.

[0103] In this application, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0104] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise" and "counterclockwise" indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0105] In this application, unless otherwise specified or limited, the terms "connect," "fix," etc. should be understood broadly. For example, "fix" can mean fixed connection, detachable connection, or integration; it can mean mechanical connection or electrical connection; it can mean direct connection or indirect connection through an intermediate medium; it can mean internal communication between two elements or interaction between two elements. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0106] In addition, the terms "first," "second," and so on, used in this application are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, features specified as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0107] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and intent of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A reaction system for liquid phase hydrogenation of aldehydes, characterized in that: The reaction system for liquid-phase hydrogenation of aldehydes comprises: A pre-hydrogenation reactor is provided with an aldehyde liquid phase inlet and a hydrogen inlet, wherein multiple first catalytic beds are vertically spaced apart in the pre-hydrogenation reactor; A main hydrogenation reactor is connected to the outlet of the pre-hydrogenation reactor, wherein multiple layers of second catalytic beds are vertically spaced apart in the main hydrogenation reactor, and a first bubble crushing unit is provided in the main hydrogenation reactor for crushing and dispersing the reaction materials; The gas-liquid separator is connected to the outlet of the main hydrogenation reactor and is used for performing gas-liquid separation on the product output from the main hydrogenation reactor.

2. The reaction system for liquid-phase hydrogenation of aldehydes according to claim 1, characterized in that: The first bubble breaking unit comprises: a first bubble breaker, arranged above the second catalytic bed layer on the top layer; The second bubble breaker is arranged at the bottom of the main hydrogenation reactor and is located below the second catalytic bed layer at the bottom layer.

3. The reaction system for liquid-phase hydrogenation of aldehydes according to claim 2, characterized in that: A stirring assembly is provided between the second catalytic bed layer and the second bubble breaker at the bottom layer in the main hydrogenation reactor.

4. The reaction system for liquid-phase hydrogenation of aldehydes according to claim 3, characterized in that: The stirring assembly comprises: a vertical stirring paddle connected to the side wall of the main hydrogenation reactor; The horizontal stirring paddle is connected to the vertical stirring paddle and is located below the vertical stirring paddle. The horizontal stirring paddle is arc-shaped and its bending direction is upward.

5. The reaction system for liquid-phase hydrogenation of aldehydes according to claim 2, characterized in that: A distribution plate is provided in the main hydrogenation reactor, and the distribution plate is arranged above the outlet of the second bubble breaker.

6. The reaction system for liquid-phase hydrogenation of aldehydes according to any one of claims 2 to 5, characterized in that: A diffuser is provided in the main hydrogenation reactor. The diffuser is provided below the second bubble breaker and is connected to the feed port of the main hydrogenation reactor.

7. The reaction system for liquid-phase hydrogenation of aldehydes according to any one of claims 1 to 5, characterized in that: A defoaming tray is provided in the main hydrogenation reactor and is located above the first bubble crushing unit.

8. The reaction system for liquid-phase hydrogenation of aldehydes according to claim 7, characterized in that: A cleaning assembly is provided above the defoaming tray, and the cleaning assembly includes: A rotating block is located above the defoaming plate and is coaxially rotatably connected to the defoaming plate; A brush is connected to the rotating block and can contact the upper surface of the defoaming disc.

9. The reaction system for liquid-phase hydrogenation of aldehydes according to any one of claims 1 to 5 and 8, characterized in that: A second bubble crushing unit is provided in the pre-hydrogenation reactor. The second bubble crushing unit includes a plurality of built-in bubble breakers. The built-in bubble breakers are provided corresponding to the first catalytic bed and are located below the first catalytic bed.

10. The reaction system for liquid-phase hydrogenation of aldehydes according to claim 9, characterized in that: At least two of the multiple built-in bubble breakers are arranged on the same vertical line.

11. The reaction system for liquid-phase hydrogenation of aldehydes according to claim 1, characterized in that: A condenser is provided between the pre-hydrogenation reactor and the main hydrogenation reactor.

12. The reaction system for liquid-phase hydrogenation of aldehydes according to claim 1, characterized in that: The reaction system for the liquid phase hydrogenation of aldehydes further comprises: A raw material buffer tank and a mixed aldehyde separation unit, wherein the raw material buffer tank is connected to the aldehyde liquid phase inlet of the pre-hydrogenation reactor through the mixed aldehyde separation unit; A hydrogen buffer tank is connected to the hydrogen inlet of the pre-hydrogenation reactor.

13. The reaction system for liquid-phase hydrogenation of aldehydes according to claim 12, characterized in that: A hydrogen filter is provided between the hydrogen buffer tank and the pre-hydrogenation reactor.

14. The reaction system for liquid-phase hydrogenation of aldehydes according to any one of claim 12, characterized in that: The reaction system for the liquid phase hydrogenation of aldehydes further comprises: The third bubble crushing unit is located outside the pre-hydrogenation reactor, the mixed aldehyde separation unit and the hydrogen buffer tank are respectively connected to the inlet of the third bubble crushing unit, and the outlet of the third bubble crushing unit is connected to the aldehyde liquid phase inlet and the hydrogen inlet of the pre-hydrogenation reactor.

15. The reaction system for liquid-phase hydrogenation of aldehydes according to claim 14, characterized in that: A liquid phase feed pump is provided between the pre-hydrogenation reactor and the third bubble crushing unit.

16. The reaction system for liquid-phase hydrogenation of aldehydes according to any one of claims 12 to 13, characterized in that: The reaction system for the liquid phase hydrogenation of aldehydes further comprises: An alcohol cooler, one end of which is connected to the gas-liquid separator, and the other end of which is connected to the raw material buffer tank.

17. The reaction system for liquid-phase hydrogenation of aldehydes according to claim 16, characterized in that: The reaction system for the liquid phase hydrogenation of aldehydes further comprises: The low-gas-liquid separator is connected to the top of the gas-liquid separator.

18. The reaction system for liquid-phase hydrogenation of aldehydes according to claim 17, characterized in that: A low-gas cooler is provided between the low-gas-liquid separator and the gas-liquid separator.

19. The reaction system for liquid-phase hydrogenation of aldehydes according to claim 18, characterized in that: The reaction system for the liquid phase hydrogenation of aldehydes further comprises: The distillation system is connected to the gas-liquid separator and the low-fraction gas-liquid separator.

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