A liquid phase hydrogenation system suitable for the production of alcohols from aldehydes
By using a bottom-in, top-out adiabatic fixed-bed liquid-phase hydrogenation system, the problems of high energy consumption, large equipment investment, and uneven gas-liquid distribution in existing technologies have been solved, achieving low-cost and high-efficiency aldehyde-to-alcohol reaction and improving the activity and lifespan of the catalyst.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHANGHAI DIYANG CHEMICAL TECHNOLOGY CO LTD
- Filing Date
- 2026-05-21
- Publication Date
- 2026-06-26
AI Technical Summary
Existing fixed-bed gas-phase hydrogenation technology has high energy consumption, large equipment investment, and poor catalyst thermal stability. Liquid-phase hydrogenation technology has uneven gas-liquid distribution, local overheating, and high risk of catalyst activation, making it difficult to apply to high-carbon chain aldehyde materials.
The adiabatic fixed-bed liquid-phase hydrogenation system with bottom inlet and top outlet includes a feed jet mixer, a ceramic ball layer, and a catalyst bed. After hydrogen is mixed with aldehyde material, it passes through the catalyst bed from bottom to top, eliminating the need for a hydrogen circulation compressor. The ceramic ball layer is used to uniformly distribute the fluid and control the catalyst temperature.
It significantly reduces the hydrogen-aldehyde ratio, lowers power consumption and operating costs, achieves uniform gas-liquid contact, controls catalyst temperature, and improves catalyst activity and lifespan.
Smart Images
Figure CN224405084U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of chemical production technology, and in particular to a liquid-phase hydrogenation system suitable for the production of alcohols from aldehydes. Background Technology
[0002] Catalytic hydrogenation of aldehydes is an important industrial process for preparing corresponding alcohols, widely used in the production of high-value-added fine chemicals such as butanol, octanol, and isodecanol. Currently, the industrial hydrogenation of aldehydes to alcohols mainly employs the following two technical routes:
[0003] 1. Fixed-bed gas-phase hydrogenation technology:
[0004] Gas-phase hydrogenation technology is mainly applicable to low-carbon aldehydes with carbon chain lengths of C8 or less, such as propionaldehyde, butyraldehyde, pentanal, and octanal. In this technology, the aldehyde material is gasified and mixed with a large amount of hydrogen, passing through a fixed-bed catalyst in gaseous form. To ensure the depth of the hydrogenation reaction and the stability of the catalyst activity, gas-phase hydrogenation typically requires maintaining a high hydrogen-aldehyde molar ratio (generally greater than 20:1), with a large excess of hydrogen. Unreacted hydrogen at the reactor outlet needs to be separated into gas and liquid phases, then pressurized by a hydrogen recirculation compressor and recycled back to the reactor inlet to participate in the reaction again.
[0005] The main disadvantages of fixed-bed gas-phase hydrogenation technology are:
[0006] 1) High energy consumption: Due to the huge amount of hydrogen circulating, the motor power of the hydrogen circulating compressor is significantly high, resulting in high power consumption and poor economic efficiency of the unit. For aldehyde hydrogenation units of the same scale, the motor power of the hydrogen circulating compressor is often 3 to 5 times that of the motor power of the liquid phase hydrogenation circulating pump.
[0007] 2) Large equipment investment: It requires the configuration of hydrogen circulation compressor and complex large-diameter circulation pipeline system. Due to the high thermal resistance of the gas phase system, the heat transfer capacity of the catalyst bed is required to be higher. Therefore, fixed tubular reactors are mostly used. The manufacturing cost of the reactor is higher than that of the trickle bed reactor for liquid phase hydrogenation.
[0008] 3) High requirements for catalyst thermal stability: The gas phase reaction has a small heat capacity and a large adiabatic temperature rise, and local hot spots are prone to appear in the catalyst bed, which accelerates catalyst deactivation;
[0009] 4) Limited applicability: For high-carbon chain aldehydes with C8 or higher, gas-phase hydrogenation technology is difficult to apply directly due to their high boiling point and difficulty in vaporization.
[0010] 2. Top-in, bottom-out adiabatic fixed-bed liquid-phase hydrogenation technology (tricooker bed):
[0011] Liquid-phase hydrogenation technology is mainly applicable to high-carbon chain aldehydes with 8 or more carbon atoms, and in recent years it has gradually expanded to the low-carbon chain field. In this technology, the aldehyde material enters the reactor in liquid form along with hydrogen, significantly reducing the hydrogen-aldehyde molar ratio (usually 1 to 5:1). This eliminates the need for a hydrogen circulation compressor, thereby effectively reducing power consumption and equipment investment.
[0012] Existing liquid-phase hydrogenation technologies mostly employ a top-in, bottom-out flow arrangement, meaning that the aldehyde liquid phase and hydrogen gas enter from the top of the reactor and flow downwards through the catalyst bed. In this operating mode, the reactor typically operates as a trickle bed: the liquid phase is a continuous phase that partially covers the catalyst particles in the form of a thin film or trickles, while the gas phase is a continuous or dispersed phase, and the catalyst bed is not completely filled with liquid.
[0013] The top-in, bottom-out adiabatic fixed-bed liquid-phase hydrogenation technology has the following drawbacks:
[0014] 1) Uneven gas-liquid distribution: Hydrogen has poor dispersion in the liquid phase, which can easily form gas-phase channels or liquid-phase channels in local areas of the bed, resulting in incomplete catalyst wetting;
[0015] 2) Local overheating and runaway temperature: Uneven gas-liquid distribution causes uneven radial and axial temperature distribution in the catalyst bed. Hot spots are formed in local areas due to the accumulation of reaction heat, which triggers side reactions such as excessive hydrogenation and condensation, resulting in a decrease in the selectivity of the target alcohol. This is especially true when the aldehyde material is a low-carbon chain aldehyde, which has high aldehyde reactivity, high reaction temperature, and more side reactions.
[0016] 3) Catalyst activation risk: During the wet activation (reduction) process of the catalyst, if a static or downflow mode is used, the contact between the activation medium and the catalyst will be uneven, the bed temperature will be difficult to control, the probability of runaway temperature is high, and the initial activity and life of the catalyst will be affected. Utility Model Content
[0017] To address the aforementioned problems, this application provides a liquid-phase hydrogenation system suitable for the production of alcohols from aldehydes.
[0018] The liquid-phase hydrogenation system for aldehyde-to-ethanol production provided in this application adopts the following technical solution:
[0019] A liquid-phase hydrogenation system suitable for aldehyde-to-ethanol production includes a liquid-phase hydrogenation reactor, which is a bottom-in, top-out adiabatic fixed-bed reactor. The liquid-phase hydrogenation reactor is provided with a feed jet mixer, a first ceramic ball layer, a catalyst bed, and a second ceramic ball layer arranged sequentially from bottom to top. The feed end of the feed jet mixer is connected to a hydrogen feed pipe and an aldehyde material feed pipe.
[0020] The discharge end of the liquid phase hydrogenation reactor is connected to a reaction liquid separation tank through a first pipeline. The reaction liquid separation tank is equipped with a first catalyst filter. The reaction liquid separation tank is connected to a product discharge module and a non-condensable gas treatment module, and a liquid level transmitter is installed on the reaction liquid separation tank.
[0021] Preferably, a first flow meter, a first solenoid valve, and a circulating pump are sequentially installed on the aldehyde material feed pipe along the aldehyde material conveying direction.
[0022] Preferably, a second flow meter and a second solenoid valve are installed sequentially on the hydrogen feed pipe along the hydrogen delivery direction.
[0023] Preferably, the non-condensable gas treatment module includes a non-condensable gas cooler and a non-condensable gas separator, and a wire mesh demister is installed in the non-condensable gas separator.
[0024] A second pipeline is installed between the reaction liquid separator and the non-condensable gas separator. The feed end of the second pipeline is located above the first catalyst filter, and the discharge end is located below the wire mesh demister.
[0025] The non-condensable gas separator is equipped with a third pipe for discharging waste gas. The feed end of the third pipe is set higher than the wire mesh demister, and a pressure transmitter, a third flow meter and a third solenoid valve are installed sequentially on the third pipe along the waste gas discharge direction.
[0026] The bottom of the non-condensable gas separator is connected to a fourth pipe, the outlet of which is connected to the reaction liquid separator, and the outlet of the fourth pipe is lower than the first catalyst filter.
[0027] Preferably, the product discharge module includes a fifth pipe and a sixth pipe, and the inlet ends of the fifth pipe and the sixth pipe are both connected to the bottom of the reaction liquid separator.
[0028] The fifth pipeline is used to transport the hydrogenated product to the downstream alcohol refining section, and a second catalyst filter, a fourth flow meter and a fourth solenoid valve are installed sequentially on the fifth pipeline along the transport direction of the hydrogenated product.
[0029] The discharge end of the sixth pipeline is connected to the inlet end of the circulating pump, and a heat transfer steam drum, a fifth solenoid valve, a fifth flow meter, and a temperature transmitter are sequentially installed on the sixth pipeline along the conveying direction of the reaction liquid.
[0030] Preferably, the bottom of the reaction liquid separation tank is also connected to a seventh pipe, the discharge end of the seventh pipe is connected to the sixth pipe, the discharge end of the seventh pipe is located between the fifth flow meter and the fifth solenoid valve, and the sixth solenoid valve is installed on the seventh pipe.
[0031] Preferably, the catalyst bed uses a copper-chromium catalyst, and the catalyst bed contains 30% to 60% copper oxide and 40% to 70% chromium oxide.
[0032] Preferably, the liquid-phase hydrogenation reactor operates at a temperature of 110–250°C and an operating pressure of 0.5–6.0 MPaG.
[0033] Preferably, the nozzle velocity of the feed jet mixer is 15-40 m / s, the length-to-diameter ratio of the throat is 3-8, the cone angle of the diffuser section is 8-15°, the height of the buffer chamber is 300-600 mm, and the diameter of the ejected hydrogen bubbles is less than or equal to 0.5 mm.
[0034] Preferably, the filling height of both the first ceramic ball layer and the second ceramic ball layer is 50-600 mm.
[0035] In summary, the liquid-phase hydrogenation system for aldehyde-to-alcohol conversion proposed in this application has at least one of the following beneficial technical effects:
[0036] 1. By adopting the liquid-phase hydrogenation mode, the hydrogen-aldehyde ratio can be significantly reduced, the hydrogen circulation compressor can be eliminated, and the power consumption and operating costs of the equipment can be greatly reduced;
[0037] 2. The operation mode of using liquid material and hydrogen to flow in parallel upward (bottom in, top out) through the catalyst bed allows the liquid phase to fill the catalyst bed as a continuous phase, achieving uniform contact between the gas and liquid phases in the radial and axial directions.
[0038] 3. By utilizing the bottom-in, top-out flow arrangement, the hydrogen-containing activation medium rises uniformly from the bottom of the bed, ensuring uniform and controllable temperature during the wet activation of the catalyst, reducing the risk of runaway temperature, and improving the initial activity of the catalyst. Attached Figure Description
[0039] Figure 1 This is a schematic diagram illustrating the overall structure of the liquid-phase hydrogenation system in an embodiment of this application.
[0040] Explanation of reference numerals in the attached drawings: 1. Liquid-phase hydrogenation reactor; 11. Feed jet mixer; 12. First ceramic ball layer; 13. Catalyst bed; 14. Second ceramic ball layer; 15. Hydrogen feed pipe; 151. Second flow meter; 152. Second solenoid valve; 16. Aldehyde feed pipe; 161. First flow meter; 162. First solenoid valve; 163. Circulation pump; 17. First pipe; 2. Reaction liquid separator; 21. Second pipe; 22. Fifth pipe; 221. Second catalyst filter; 222. Fourth flow meter; 223, Fourth solenoid valve; 23, Sixth pipeline; 231, Heat transfer steam drum; 232, Fifth solenoid valve; 233, Fifth flow meter; 234, Temperature transmitter; 24, Level transmitter; 25, Seventh pipeline; 251, Sixth solenoid valve; 26, First catalyst filter; 3, Non-condensable gas cooler; 4, Non-condensable gas separator; 41, Wire mesh demister; 42, Third pipeline; 421, Pressure transmitter; 422, Third flow meter; 423, Third solenoid valve; 43, Fourth pipeline. Detailed Implementation
[0041] The following combination Figure 1 This application will be described in further detail.
[0042] Example
[0043] This application discloses a liquid-phase hydrogenation system suitable for the production of alcohols from aldehydes. (Refer to...) Figure 1 It mainly includes a liquid-phase hydrogenation reactor 1. The liquid-phase hydrogenation reactor 1 is an adiabatic fixed-bed reactor with top inlet and bottom outlet. Inside the liquid-phase hydrogenation reactor 1, a feed jet mixer 11, a first ceramic ball layer 12, a catalyst bed 13 and a second ceramic ball layer 14 are arranged sequentially from bottom to top. The feed end of the feed jet mixer 11 is connected to a hydrogen feed pipe 15 and an aldehyde material feed pipe 16.
[0044] The aldehyde material is propionaldehyde, butyraldehyde, octenal, or C10-C16 aldehyde material. A first flow meter 161, a first solenoid valve 162, and a circulating pump 163 are sequentially installed along the aldehyde material conveying direction on the aldehyde material feed pipe 16. The first flow meter 161 can monitor the flow rate of the aldehyde material conveyed from the aldehyde material feed pipe 16 to the liquid-phase hydrogenation reactor 1. Based on the data monitored by the first flow meter 161, the opening degree of the first solenoid valve 162 can be adjusted through an external control system to achieve the technical effect of automatically adjusting the aldehyde material feed flow rate.
[0045] A second flow meter 151 and a second solenoid valve 152 are sequentially installed on the hydrogen feed pipeline 15 along the hydrogen delivery direction. The second flow meter 151 can monitor the flow rate of hydrogen delivered from the hydrogen feed pipeline 15 to the liquid phase hydrogenation reactor 1. Based on the data monitored by the second flow meter 151, the opening degree of the second solenoid valve 152 can be adjusted by an external control system to achieve the technical effect of automatically adjusting the hydrogen feed flow rate.
[0046] The nozzle velocity of the feed jet mixer 11 is 15-40 m / s, the length-to-diameter ratio of the throat is 3-8, the cone angle of the diffuser section is 8-15°, the height of the buffer chamber is 300-600 mm, and the diameter of the ejected hydrogen bubbles is less than or equal to 0.5 mm; the filling height of the first ceramic ball layer 12 and the second ceramic ball layer 14 is 50-600 mm (preferably 200 mm in this embodiment).
[0047] The feed end of the feed jet mixer 11 is also connected to a nitrogen delivery pipe. Nitrogen is introduced through the nitrogen delivery pipe to replace the air in the catalyst bed 13 in the liquid phase hydrogenation reactor 1 before catalyst activation, providing an inert gas environment for the catalyst and preventing the reduced catalyst from re-oxidizing with oxygen in the air. During wet activation of the catalyst, the alcohol material is circulated to raise the temperature of the catalyst bed 13. An appropriate amount of nitrogen is added to the alcohol material feed to ensure that the liquid phase hydrogenation reactor 1 is in an inert gas environment. After the liquid phase hydrogenation reactor is shut down and the liquid material is withdrawn, the nitrogen introduced through the nitrogen delivery pipe can replace the catalyst bed 13 and the reactor, blowing out the residual hydrogen in the liquid phase hydrogenation reactor 1.
[0048] After hydrogen and aldehyde materials enter the feed jet mixer 11, they are mixed by the feed jet mixer 11, so that hydrogen is uniformly dispersed in the aldehyde materials in the form of bubbles less than or equal to 0.5 mm. The aldehyde materials with uniformly mixed hydrogen bubbles are uniformly dispersed by the feed jet mixer 11.
[0049] The aldehyde material sprayed by the jet mixer is mixed and dispersed again through the first ceramic ball layer 12 and then enters the catalyst bed 13. Hydrogen and aldehyde material pass through the catalyst bed 13 from bottom to top and react fully.
[0050] The first ceramic ball layer 12 has the following functions: preventing the catalyst from falling downwards, mitigating the impact of the feed jet mixer 11 on the catalyst bed, and acting as a distributor; it is filled with two sizes of ceramic balls, a mixture of 6mm and 13mm diameter ceramic balls. The 6mm diameter ceramic balls prevent the catalyst from falling downwards, while the 13mm diameter ceramic balls mitigate the impact of the jet from the injector 11 outlet flow on the catalyst bed. The 13mm ceramic balls are larger than the 6mm ceramic balls, resulting in a relatively lower pressure drop when the fluid passes through them; the first ceramic ball layer 12, filled with the two types of ceramic balls, can change the channel through which the fluid enters the catalyst bed, thus achieving a uniform distribution of aldehyde materials and hydrogen.
[0051] Because of the small catalyst particle size, the second ceramic ball layer 14 can effectively prevent catalyst particles from being carried out of the bed with the gas-liquid flow. In combination with the size of the copper-chromium catalyst used, the ceramic balls used in the second ceramic ball layer 14 have a diameter of 6 mm.
[0052] In some other embodiments, the size of the ceramic balls filled in the first ceramic ball layer 12 and the size of the ceramic balls filled in the second ceramic ball layer 14 may be adjusted according to actual needs, without limitation or elaboration here.
[0053] It should be noted that the catalyst used in catalyst bed 13 is a copper-chromium catalyst, with copper oxide content of 30% to 60% and chromium oxide content of 40% to 70% in catalyst bed 13; and the operating temperature of liquid phase hydrogenation reactor 1 is 110 to 250℃ and the operating pressure is 0.5 to 6.0 MPaG.
[0054] The operating temperature can be set according to different aldehyde materials. For example, if the aldehyde material is propionaldehyde, the operating temperature of the liquid phase hydrogenation reactor 1 is preferably set to 120°C; if the aldehyde material is butyraldehyde, the operating temperature of the liquid phase hydrogenation reactor 1 is preferably set to 140°C; if the aldehyde material is octenal, the operating temperature of the liquid phase hydrogenation reactor 1 is preferably set to 170°C; if the aldehyde material is a high carbon aldehyde (C12~C16 aldehyde), the operating temperature of the liquid phase hydrogenation reactor 1 is preferably set to 220°C.
[0055] The operating pressure can be set according to different aldehyde materials. For example, if the aldehyde material is a low-carbon chain aldehyde (C8 and below), the operating pressure of the liquid-phase hydrogenation reactor 1 is preferably set to about 3.0 MPaG; if the aldehyde material is a high-carbon chain aldehyde (C12 to C16 aldehyde), the operating pressure of the liquid-phase hydrogenation reactor 1 is preferably set to about 5.0 MPaG.
[0056] Furthermore, to ensure the hydrogenation effect of the aldehyde material, the feed molar ratio of hydrogen to aldehyde material is 1 to 5:1, and in this embodiment, it is preferably 1.5:1. In some other embodiments, the feed molar ratio of hydrogen to aldehyde material can also be adjusted according to the type of aldehyde material, which will not be limited or elaborated here.
[0057] By adopting the liquid-phase hydrogenation mode, the hydrogen-aldehyde ratio can be significantly reduced, eliminating the need for a hydrogen circulation compressor and drastically reducing the power consumption and operating costs of the unit. The operation mode, in which liquid material and hydrogen flow in parallel upwards (bottom in, top out) through the catalyst bed 13, allows the liquid phase to fill the catalyst bed 13 as a continuous phase, achieving uniform contact between the gas and liquid phases in the radial and axial directions. The bottom in, top out flow arrangement ensures that the hydrogen-containing activation medium rises uniformly from the bottom of the bed, making the temperature uniform and controllable during the wet activation of the catalyst, reducing the risk of overheating, and improving the initial activity of the catalyst.
[0058] Reference Figure 1 The discharge end of the liquid phase hydrogenation reactor 1 is connected to the reaction liquid separation tank 2 through the first pipe 17. The reaction liquid separation tank 2 is equipped with a first catalyst filter 26. The reaction liquid separation tank 2 is connected to the product discharge module and the non-condensable gas treatment module. The reaction liquid separation tank 2 is also equipped with a level transmitter 24 for monitoring the liquid level of the reaction liquid inside.
[0059] The non-condensable gas treatment module includes a non-condensable gas cooler 3 and a non-condensable gas separator 4. A wire mesh demister 41 is installed inside the non-condensable gas separator 4. A second pipe 21 is installed between the reaction liquid separator 2 and the non-condensable gas separator 4. The inlet end of the second pipe 21 is located above the first catalyst filter 26, and the outlet end is located below the wire mesh demister 41. A third pipe 42 for discharging waste gas is installed on the non-condensable gas separator 4. The inlet end of the third pipe 42 is set higher than the wire mesh demister 41, and the outlet end of the third pipe 42 is connected to the waste gas treatment module for incineration treatment. A pressure transmitter 421, a third flow meter 422, and a third solenoid valve 423 are installed sequentially on the third pipe 42 along the direction of waste gas discharge. A fourth pipe 43 is connected to the bottom of the non-condensable gas separator 4. The outlet end of the fourth pipe 43 is connected to the reaction liquid separator 2, and the outlet end of the fourth pipe 43 is lower than the first catalyst filter 26.
[0060] After hydrogenation in catalyst bed 13, the reaction liquid is transported to reaction liquid separator 2 via first pipeline 17. First catalyst filter 26 removes residual catalyst from the reaction liquid. Non-condensable gas (which consists of unreacted excess hydrogen (accounting for the largest proportion, around 80%), methane and nitrogen entrained in the fresh hydrogen feed, etc.) is cooled by non-condensable gas cooler 3 and then transported to non-condensable gas separator 4 via second pipeline 21. Wire mesh demister 41 in non-condensable gas separator 4 removes droplets or mist from the non-condensable gas. The resulting waste gas is discharged to the waste gas treatment system via third pipeline 42, while the remaining reaction liquid is returned to reaction liquid separator 2 via fourth pipeline 43.
[0061] Based on the data monitored by the pressure transmitter 421 installed on the third pipeline 42, the external control system can adjust the opening of the second solenoid valve 152 on the hydrogen feed pipeline 15 according to the pressure of the discharged exhaust gas; based on the data monitored by the third flow meter 422 installed on the third pipeline 42, the external control system can automatically adjust the opening of the third solenoid valve 423 according to the flow rate of the discharged exhaust gas.
[0062] Reference Figure 1 The product discharge module includes a fifth pipe 22 and a sixth pipe 23, the inlet ends of which are connected to the bottom of the reaction liquid separator 2. The fifth pipe 22 is used to transport the hydrogenated product to the downstream alcohol refining section, and a second catalyst filter 221, a fourth flow meter 222, and a fourth solenoid valve 223 are installed sequentially on the fifth pipe 22 along the direction of hydrogenated product transport. The outlet end of the sixth pipe 23 is connected to the inlet end of the circulating pump 163, and a heat transfer steam drum 231, a fifth solenoid valve 232, a fifth flow meter 233, and a temperature transmitter 234 are installed sequentially on the sixth pipe 23 along the direction of reaction liquid transport.
[0063] The bottom of the reaction liquid separator 2 is also connected to a seventh pipe 25. The discharge end of the seventh pipe 25 is connected to the sixth pipe 23. The discharge end of the seventh pipe 25 is located between the fifth flow meter 233 and the fifth solenoid valve 232, and the sixth solenoid valve 251 is installed on the seventh pipe 25.
[0064] Part of the reaction liquid in the reaction liquid separator 2 is transported to the downstream alcohol refining section through the fifth pipeline 22. When the reaction liquid flows through the fifth pipeline 22, it can be filtered twice by the second catalyst filter 221. The external control system can automatically adjust the opening of the fourth solenoid valve 223 according to the monitoring data of the liquid level transmitter 24 on the reaction liquid separator 2 and the monitoring data of the fourth flow meter 222 on the fifth pipeline 22.
[0065] Another part of the reaction liquid in the reaction liquid separation tank 2 is transported out by the sixth pipeline 23. After being cooled by the heat transfer steam drum 231, it is mixed with fresh aldehyde material and then pumped by the circulation pump 163 to the feed jet mixer 11 for circulation reaction.
[0066] The external control system can automatically adjust the opening of the fifth solenoid valve 232 based on the monitoring data of the temperature transmitter 234; based on the data monitored by the fifth flow meter 233, the external control system can automatically adjust the opening of the sixth solenoid valve 251 to regulate the temperature of the reaction liquid returning to the liquid phase hydrogenation reactor 1. Through the circulating reaction liquid, the catalyst bed 13 can maintain a suitable temperature environment, which ensures the activity of the catalyst.
[0067] The implementation principle of a liquid-phase hydrogenation system for aldehyde-to-ethanol production according to an embodiment of this application is as follows: Using a liquid-phase hydrogenation mode can significantly reduce the hydrogen-to-aldehyde ratio, eliminate the need for a hydrogen circulation compressor, and substantially reduce the power consumption and operating costs of the device; employing an operation mode where liquid material and hydrogen flow in parallel upwards (bottom in, top out) through the catalyst bed 13, the liquid phase fills the catalyst bed 13 as a continuous phase, achieving uniform contact between the gas and liquid phases in the radial and axial directions; utilizing the bottom in, top out flow arrangement allows the hydrogen-containing activation medium to rise uniformly from the bottom of the bed, achieving uniform and controllable temperature during the wet activation process of the catalyst, reducing the risk of overheating, and improving the initial activity of the catalyst.
[0068] The above are all preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.
Claims
1. A liquid phase hydrogenation system suitable for the production of alcohols from aldehydes, characterized in that, The reactor includes a liquid-phase hydrogenation reactor (1), which is an adiabatic fixed-bed reactor with bottom inlet and top outlet. The liquid-phase hydrogenation reactor (1) is provided with a feed jet mixer (11), a first ceramic ball layer (12), a catalyst bed (13), and a second ceramic ball layer (14) arranged sequentially from bottom to top. The feed jet mixer (11) is connected to a hydrogen feed pipe (15) and an aldehyde material feed pipe (16) at its feed end. The discharge end of the liquid phase hydrogenation reactor (1) is connected to a reaction liquid separation tank (2) through a first pipe (17). A first catalyst filter (26) is installed in the reaction liquid separation tank (2). The reaction liquid separation tank (2) is connected to a product discharge module and a non-condensable gas treatment module. A liquid level transmitter (24) is installed on the reaction liquid separation tank (2).
2. The liquid-phase hydrogenation system for aldehyde-to-alcohol conversion according to claim 1, characterized in that, The aldehyde material feed pipe (16) is equipped with a first flow meter (161), a first solenoid valve (162) and a circulating pump (163) in sequence along the aldehyde material conveying direction.
3. A liquid-phase hydrogenation system for aldehyde-to-alcohol conversion according to claim 2, characterized in that, The hydrogen feed pipe (15) is equipped with a second flow meter (151) and a second solenoid valve (152) in sequence along the hydrogen conveying direction.
4. A liquid-phase hydrogenation system for aldehyde-to-alcohol conversion according to claim 1, characterized in that, The non-condensable gas treatment module includes a non-condensable gas cooler (3) and a non-condensable gas separator (4), and a wire mesh demister (41) is installed inside the non-condensable gas separator (4). A second pipe (21) is installed between the reaction liquid separator (2) and the non-condensable gas separator (4). The feed end of the second pipe (21) is located above the first catalyst filter (26), and the discharge end is located below the wire mesh demister (41). The non-condensable gas separator (4) is equipped with a third pipe (42) for discharging waste gas. The feed end of the third pipe (42) is set higher than the wire mesh demister (41). A pressure transmitter (421), a third flow meter (422) and a third solenoid valve (423) are installed on the third pipe (42) in sequence along the waste gas discharge direction. The bottom of the non-condensable gas separator (4) is connected to a fourth pipe (43), the outlet end of the fourth pipe (43) is connected to the reaction liquid separator (2), and the outlet end of the fourth pipe (43) is lower than the first catalyst filter (26).
5. A liquid-phase hydrogenation system for aldehyde-to-alcohol conversion according to claim 4, characterized in that, The product discharge module includes a fifth pipe (22) and a sixth pipe (23), the inlet ends of which are connected to the bottom of the reaction liquid separator (2); The fifth pipeline (22) is used to transport the hydrogenated product to the downstream alcohol refining section, and the fifth pipeline (22) is equipped with a second catalyst filter (221), a fourth flow meter (222) and a fourth solenoid valve (223) in sequence along the transport direction of the hydrogenated product. The discharge end of the sixth pipe (23) is connected to the feed end of the circulating pump (163), and the sixth pipe (23) is equipped with a heat transfer steam drum (231), a fifth solenoid valve (232), a fifth flow meter (233) and a temperature transmitter (234) in sequence along the conveying direction of the reaction liquid.
6. A liquid-phase hydrogenation system for aldehyde-to-alcohol conversion according to claim 5, characterized in that, The bottom of the reaction liquid separator (2) is also connected to a seventh pipe (25). The discharge end of the seventh pipe (25) is connected to the sixth pipe (23). The discharge end of the seventh pipe (25) is located between the fifth flow meter (233) and the fifth solenoid valve (232). The sixth solenoid valve (251) is installed on the seventh pipe (25).
7. A liquid-phase hydrogenation system for aldehyde-to-alcohol conversion according to claim 1, characterized in that, The catalyst bed (13) uses a copper-chromium catalyst.
8. A liquid-phase hydrogenation system for aldehyde-to-alcohol conversion according to claim 1, characterized in that, The filling height of the first ceramic ball layer (12) and the second ceramic ball layer (14) is 50-600mm.