Liquid-phase hydrogenation equipment suitable for preparing alcohol from short-carbon-chain aldehyde

Abstract

The invention relates to liquid-phase hydrogenation equipment suitable for preparing alcohol from short-carbon-chain aldehyde, which comprises a reactor, a first-section catalyst bed layer and a second-section catalyst bed layer are filled in the reactor, and a distributor is mounted in the reactor; an interlayer heat exchange coil pipe is arranged in the reactor, the interlayer heat exchange coil pipe is connected with a first pipeline and a second pipeline, and the second pipeline is connected with the distributor; the reactor is communicated with a third pipeline for supplying gas phase hydrogen, and the third pipeline extends into the reactor and is connected with the distributor; the reactor is connected with a fourth pipeline, a circulating pump and a heat transfer steam pocket are mounted on the fourth pipeline, and the fourth pipeline is connected with a fifth pipeline and a sixth pipeline; the fifth pipeline is communicated with the distributor; a central pipe filled with a third catalyst bed layer is mounted in the middle of the second catalyst bed layer, and the central pipe is communicated with a subsequent rectification system; the sixth pipeline extends into the reactor and is communicated with the central pipe; the gas phase hydrogen supply system is communicated with a seventh pipeline, and the seventh pipeline is communicated with the sixth pipeline.

Description

Technical Field

[0001] This application relates to the field of liquid-phase hydrogenation technology for producing alcohols from short-chain aldehydes, and in particular to a liquid-phase hydrogenation apparatus suitable for producing alcohols from short-chain aldehydes. Background Technology

[0002] The production of alcohols from short-chain aldehydes mainly involves catalytic hydrogenation of aldehydes to produce short-chain alcohols. In existing technologies, gas-phase hydrogenation is mostly used for the production of alcohols from short-chain aldehydes, while liquid-phase hydrogenation processes and equipment are often less studied.

[0003] Existing aldehyde-to-ethanol liquid-phase hydrogenation equipment mainly uses reaction liquid circulation to remove reaction heat. This results in a large reaction liquid circulation volume and high power consumption of the circulation pump, leading to excessive energy consumption. Furthermore, most existing aldehyde-to-ethanol liquid-phase hydrogenation equipment uses a single-stage catalyst loading, resulting in a high catalyst bed that is prone to channeling, leading to localized excessively high and uneven temperatures within the catalyst bed, increasing the probability of side reactions and byproducts. Additionally, most existing aldehyde-to-ethanol liquid-phase hydrogenation equipment uses a single catalyst loading method. Considering current applications, in the hydrogenation of aldehydes, such as the hydrogenation of octenal to octanol, a single copper catalyst cannot achieve complete conversion of octenal, requiring a subsequent hydrogenation stage, resulting in a long hydrogenation process and multiple pieces of equipment. Summary of the Invention

[0004] To address the aforementioned issues, this application provides a liquid-phase hydrogenation apparatus suitable for the production of alcohols from short-chain aldehydes.

[0005] The liquid-phase hydrogenation equipment for the production of alcohols from short-chain aldehydes provided in this application adopts the following technical solution: A liquid-phase hydrogenation device suitable for the production of alcohols from short-chain aldehydes includes a reactor, wherein the reactor is filled with a first catalyst bed and a second catalyst bed, the catalyst composition of the first catalyst bed and the second catalyst bed is the same, the first catalyst bed is located above the second catalyst bed, and a distributor is installed in the reactor, and the distributor is positioned directly above the first catalyst bed. The reactor is equipped with an interlayer heat exchange coil. The inlet of the interlayer heat exchange coil is connected to a first pipe for supplying aldehyde material from the upper stage. A first regulating valve for regulating the aldehyde material is installed on the first pipe. The outlet of the interlayer heat exchange coil is connected to a second pipe for conveying the preheated aldehyde material. The outlet end of the second pipe extends into the reactor and is connected to a distributor. The reactor is connected to a third pipe, the inlet end of which is connected to a gaseous hydrogen supply system, the outlet end of which extends into the reactor and is connected to a distributor, and a second regulating valve is installed on the third pipe. The bottom of the reactor is connected to a fourth pipe, on which a circulating pump and a heat transfer steam drum are installed. The circulating pump and the heat transfer steam drum are arranged sequentially along the conveying direction of the reaction liquid, and the outlet end of the fourth pipe is connected to a fifth pipe and a sixth pipe. The outlet end of the fifth pipe extends into the interior of the reactor and is connected to the distributor; A central tube is installed axially in the middle of the second catalyst bed, and a third catalyst bed is filled inside the central tube. The outlet end of the central tube is connected to the subsequent distillation system. The catalyst composition of the third catalyst bed is different from that of the first and second catalyst beds. The outlet end of the sixth pipe extends into the reactor and is connected to the inlet end of the central tube. A third regulating valve is installed on the sixth pipe. The gaseous hydrogen supply system is connected to a seventh pipeline, the outlet of which is connected to a sixth pipeline, and a fourth regulating valve is installed on the seventh pipeline.

[0006] By adopting the above technical solution, in the actual production and processing process, the aldehyde material in the upper section flows through the first pipeline to the interlayer heat exchange coil for preheating, and then is sent out through the second pipeline. The aldehyde material and gaseous hydrogen are dispersed and uniformly mixed in the distributor inside the reactor to form a reaction liquid. When the aldehyde material in the reaction liquid passes through the first catalyst bed, it undergoes catalytic hydrogenation to produce alcohol, releasing heat of reaction. The reaction liquid passes through the interlayer heat exchange coil and comes into contact with it. The interlayer heat exchange coil can exchange heat between the reaction liquid and the aldehyde material, thereby lowering the temperature of the reaction liquid to complete the first cold quench treatment. At the same time, the aldehyde material absorbs the heat of reaction and its temperature rises to complete the preheating treatment. Subsequently, the reaction liquid continues to pass through the second catalyst bed, where the aldehyde material is further catalytically hydrogenated to produce alcohol. Then, the reaction liquid is pressurized and drawn out by the circulating pump and passes through the fourth pipeline through the heat transfer steam drum. The heat transfer steam drum cools and exchanges heat with the reaction liquid, causing the temperature of the reaction liquid to drop, completing the second cold quench treatment of the reaction liquid. After being drawn out through the fourth pipe, the reaction liquid is split into the fifth and sixth pipes: the portion of the reaction liquid split from the sixth pipe flows to the central pipe after being supplemented with gaseous hydrogen through the seventh pipe. The aldehyde material in the reaction liquid is further catalyzed by the third catalyst bed packed in the central pipe to generate alcohol. The generated alcohol product is drawn out through the central pipe to the subsequent distillation system; the other portion of the reaction liquid split from the fifth pipe flows back to the distributor and is recirculated through the first catalyst bed, the interlayer heat exchange coil, the second catalyst bed, and the third catalyst bed, which allows the remaining aldehyde material in the reaction liquid to be fully hydrogenated and generate alcohol. Through the interlayer heat exchange coil built between the first and second catalyst beds, the aldehyde material can be preheated by the reaction liquid that has been heated after the first catalysis. At the same time, the reaction liquid can be chilled by the aldehyde material, which lowers the temperature of the reaction liquid and prevents the activity of the second catalyst bed from being reduced due to local overheating. When the reaction liquid, after being cooled by heat exchange, flows through the second catalyst bed, it undergoes secondary catalysis to further generate alcohol. After being chilled a second time by the heat transfer steam drum, the cooled reaction liquid is guided by the sixth pipe through the third catalyst bed filled in the central tube. The third catalyst bed filled in the central tube can further catalyze and promote the formation of alcohol. At the same time, because the reaction liquid undergoes secondary chilling by the heat transfer steam drum, the temperature of the third catalyst bed is prevented from becoming too high, thus ensuring the activity of the third catalyst bed.By integrating the first catalyst bed, the interlayer heat exchange coil for preheating the aldehyde material, the second catalyst bed, and the third catalyst bed inside the reactor, the hydrogenation process is shortened. The two processes of preheating the aldehyde material and quenching the reaction liquid flowing out of the first catalyst bed are integrated into the interlayer heat exchange coil, thus shortening the hydrogenation process, reducing the number of equipment, and saving energy. Furthermore, since the catalysis is carried out in three stages—the first, second, and third catalyst beds—with interlayer heat exchange coils between the first and second catalyst beds and heat transfer steam drums between the second and third catalyst beds, the catalyst bed height is shortened, preventing channeling and avoiding localized overheating and temperature unevenness, thus reducing the probability of side reactions and the content of byproducts. Because the third catalyst bed is packed inside the central tube, which is installed at the center of the second catalyst bed, the space occupied by the third catalyst bed within the reactor can be further reduced, resulting in a more compact internal structure. Since the catalyst packed in the third catalyst bed has a different composition than the catalysts packed in the first and second catalyst beds, the synergistic effect of the two catalyst materials can achieve complete hydrogenation of unsaturated aldehydes.

[0007] Preferably, both the first and second catalyst beds are filled with copper-based catalysts, and the bed temperatures of the first and second catalyst beds are 150–190°C.

[0008] Preferably, the third catalyst bed is filled with a nickel-based catalyst.

[0009] Preferably, a distribution plate is installed inside the reactor. The distribution plate is located between the first catalyst bed and the interlayer heat exchange coil. The distribution plate has several through holes, which are distributed in an equilateral triangle. The diameter of each through hole is 5 mm, and the center distance between the through holes is 12-15 mm.

[0010] By adopting the above technical solution, the reaction liquid can be homogenized through the distribution plate, so that the reaction liquid can contact and exchange heat with the interlayer heat exchange coil evenly and fully. This makes the temperature of the reaction liquid more uniform when cooling down, and at the same time ensures the preheating effect of the aldehyde material flowing in the interlayer heat exchange coil.

[0011] Preferably, the interlayer heat exchange coil is a multi-group coiled smooth tube, and the inner diameter of the smooth tube is 25mm.

[0012] Preferably, a temperature transmitter is installed on the second pipeline, and the signal output terminal of the temperature transmitter is connected to the signal input terminal of the control system, and the signal output terminal of the control system is connected to the signal input terminal of the first regulating valve.

[0013] By adopting the above technical solution, the control system can determine whether the preheating of the aldehyde material is qualified based on the temperature of the preheated aldehyde material in the second pipeline, and can adjust the opening of the first regulating valve to regulate the flow rate of the aldehyde material flowing through the interlayer heat exchange coil.

[0014] Preferably, a pressure transmitter is installed on the reactor, the signal output terminal of the pressure transmitter is connected to the signal input terminal of the control system, and the signal output terminal of the control system is connected to the signal input terminal of the second regulating valve.

[0015] By adopting the above technical solution, the control system can evaluate the amount of gaseous hydrogen added based on the signal output by the pressure transmitter and the pressure inside the reactor, and adjust the opening of the second regulating valve accordingly to adjust the amount of gaseous hydrogen replenishment, so that the pressure inside the hydrogenation reactor remains stable.

[0016] Preferably, the reactor reaction method includes the following steps: Step S1: The aldehyde material from the upper stage is preheated by the reaction liquid passing through the first catalyst bed, so that the temperature of the aldehyde material is raised to 130-150°C. The gaseous hydrogen and the preheated aldehyde material are transported to the distributor built into the reactor. The gaseous hydrogen and aldehyde material are dispersed and uniformly mixed by the distributor to form a reaction liquid. Step S2: After the reaction liquid passes through the first catalyst bed filled with copper-based catalyst at a temperature of 150-190°C, the reaction liquid is evenly distributed through a distribution plate, so that the reaction liquid comes into uniform and sufficient contact with the interlayer heat exchange coil through which the aldehyde material flows. The heat exchange coil between the reaction liquid and the aldehyde material is carried out through the interlayer heat exchange coil, completing the first cooling treatment of the reaction liquid, so that the temperature of the reaction liquid drops to 130-150°C. Step S3: After the reaction liquid passes through the second catalyst bed filled with copper-based catalyst and at a temperature of 150-190°C, the reaction liquid that has passed through the second catalyst bed is extracted from the reactor by a circulating pump, and the reaction liquid that has passed through the second catalyst bed is subjected to a second cooling treatment by a heat transfer steam drum, so that the temperature of the reaction liquid drops to 130-150°C. Step S4: The reaction liquid that underwent secondary quenching in step S3 is split through the fifth and sixth pipes. Part of the reaction liquid is transported to the central pipe through the sixth pipe, so that the reaction liquid passes through the third catalyst bed filled with nickel-based catalyst through the central pipe. The reaction liquid that has passed through the third catalyst bed is then transported to the subsequent distillation system. At the same time, another part of the reaction liquid is transported back to the distributor through the fifth pipe, and steps S2 and S3 are repeated.

[0017] Preferably, step S1 includes the following steps: Step S11: The aldehyde material from the upper section is fed into the interlayer heat exchange coil through the first pipeline. The reaction liquid that has passed through the first catalyst bed exchanges heat with the aldehyde material through the interlayer heat exchange coil. The aldehyde material absorbs the heat of reaction from the reaction liquid and its temperature rises. Step S12: The preheated aldehyde material is transported to the distributor built into the reactor through the second pipeline. The temperature of the aldehyde material flowing in the second pipeline is obtained by the temperature transmitter. The opening of the first regulating valve on the first pipeline is adjusted by the control system according to the temperature of the aldehyde material flowing in the second pipeline, so that the temperature range of the aldehyde material output by the interlayer heat exchange coil is maintained at 130-150℃. Step S13: Gas-phase hydrogen is transported to the distributor in step S12 through the third pipeline. The internal pressure data of the reactor is obtained through the pressure transmitter. The opening of the second regulating valve on the third pipeline is adjusted by the control system according to the internal pressure data of the reactor so that the internal pressure of the reactor is maintained at 2.0 to 4.0 MPaG. Step S14: The gaseous hydrogen and aldehyde material are fully dispersed and mixed using a distributor to prepare a reaction solution.

[0018] Preferably, step S2 includes the following steps: Step S21: The reaction liquid passing through the first catalyst bed is uniformly distributed through the porous distribution disk below the first catalyst bed, so that the reaction liquid passing through the first catalyst bed flows out evenly. Step S22: The reaction liquid after uniform distribution is subjected to cooling treatment through the interlayer heat exchange coil through which the aldehyde material from the upper section flows.

[0019] Step S4 includes the following steps: Step S41: The reaction liquid that has passed through the second catalyst bed and the heat transfer steam drum is diverted through the sixth pipe and transported to the central pipe. The gaseous hydrogen required for alcohol production is replenished to the reaction liquid in the sixth pipe through the seventh pipe. The other diverted reaction liquid is returned to the reactor through the fifth pipe, and steps S2 and S3 are repeated. Step S42: Catalyze the reaction liquid transported in the sixth pipeline through the third catalyst bed filled in the central tube; Step S43: The alcohol product that has passed through the third catalyst bed is transported to the subsequent distillation system through the central tube.

[0020] In summary, the liquid-phase hydrogenation apparatus for the production of alcohols from short-chain aldehydes proposed in this application has at least one of the following beneficial technical effects: 1. By integrating the first catalyst bed, the interlayer heat exchange coil for preheating the aldehyde material, the second catalyst bed, and the third catalyst bed inside the reactor, the hydrogenation process is shortened. The two processes of preheating the aldehyde material and quenching the reaction liquid flowing out of the first catalyst bed are integrated into the interlayer heat exchange coil, which can shorten the hydrogenation process, reduce the number of equipment and save energy. 2. Since the catalysis is carried out in three stages: the first catalyst bed, the second catalyst bed, and the third catalyst bed, and an interlayer heat exchange coil is installed between the first and second catalyst beds, and a heat transfer steam drum is installed between the second and third catalyst beds, the catalyst bed height can be shortened, avoiding channeling. At the same time, it can prevent excessively high local temperatures and uneven temperatures in the catalyst bed, reducing the probability of side reactions and the content of by-products. 3. The third catalyst bed is filled in the central tube, which is installed in the center of the second catalyst bed. This can further reduce the space occupied by the third catalyst bed in the reactor, making the internal structure of the reactor more compact. 4. Since the catalyst packed in the third catalyst bed has a different composition than the catalyst packed in the first and second catalyst beds, the full hydrogenation of unsaturated aldehydes can be achieved through the synergistic effect of the two catalyst materials. Attached Figure Description

[0021] Figure 1 This is a schematic diagram illustrating the overall structure of the hydrogen refueling equipment in an embodiment of this application.

[0022] Explanation of reference numerals in the attached drawings: 1. Reactor; 11. First catalyst bed; 12. Second catalyst bed; 13. Interlayer heat exchange coil; 131. First pipe; 132. Second pipe; 1321. Temperature transmitter; 133. First regulating valve; 14. Third pipe; 141. Second regulating valve; 15. Fourth pipe; 151. Circulating pump; 152. Heat transfer steam drum; 16. Fifth pipe; 17. Sixth pipe; 171. Third regulating valve; 18. Central pipe; 181. Third catalyst bed; 19. Seventh pipe; 191. Fourth regulating valve; 2. Distribution plate; 3. Pressure transmitter. Detailed Implementation

[0023] The following combination Figure 1 This application will be described in further detail.

[0024] Example 1 This application discloses a liquid-phase hydrogenation apparatus suitable for the production of alcohols from short-chain aldehydes. (Refer to...) Figure 1It mainly includes a reactor 1, which is filled with a first catalyst bed 11 and a second catalyst bed 12, with the first catalyst bed 11 located above the second catalyst bed 12.

[0025] In this embodiment, the catalysts packed in the first catalyst bed 11 and the second catalyst bed 12 are the same, both being nickel-based catalysts, noble metal-based catalysts, nickel-copper catalysts, or catalysts composed of copper and other metals, such as supported Ni-Cr catalysts, Ni-Al2O3-ZrO2 catalysts, Ni-ZrO2-CuO-MnO catalysts, Ni-Cr-Mo-K / SiO2 catalysts, Ni-Al2O3-TiO2 catalysts, Ni-Cu-Cr-alkali metal catalysts, etc. In this embodiment, both the first catalyst bed 11 and the second catalyst bed 12 preferably use copper-based catalysts. When the reactor 1 is started, to ensure the activity of the copper-based catalysts in the first catalyst bed 11 and the second catalyst bed 12, the temperature of both the first catalyst bed 11 and the second catalyst bed 12 is 150–190°C, with 150°C being preferred in this embodiment.

[0026] An interlayer heat exchange coil 13 is installed inside the reactor 1. The interlayer heat exchange coil 13 is located between the first catalyst bed 11 and the second catalyst bed 12, and both the outlet end and the inlet end of the interlayer heat exchange coil 13 extend to the outside of the reactor 1.

[0027] The inlet end of the interlayer heat exchange coil 13 is connected to a first pipe 131 for inputting aldehyde material flowing out of the upper section, and a first regulating valve 133 for controlling the aldehyde material is installed on the first pipe 131; the outlet end of the interlayer heat exchange coil 13 is connected to a second pipe 132 for discharging aldehyde material.

[0028] A temperature transmitter 1321 is installed on the second pipeline 132 to detect the temperature of the aldehyde material after preheating by the interlayer preheating coil. The signal output terminal of the temperature transmitter 1321 is connected to the signal input terminal of the control system, and the data output terminal of the control system is connected to the first regulating valve 133. The control system adjusts the opening of the first regulating valve 133 according to the temperature data of the preheated aldehyde material output by the temperature transmitter 1321, thereby regulating the flow rate of the aldehyde material in the interlayer heat exchange coil 13.

[0029] It should be noted that in this embodiment, the interlayer heat exchange coil 13 is a bare tube with an inner diameter of 25mm, and multiple sets are coiled (generally 4 sets are selected). In some other embodiments, a bare tube with an inner diameter of 35mm can also be selected according to actual needs, which will not be limited or elaborated here.

[0030] A distributor is installed inside reactor 1, positioned above the middle of the first catalyst bed 11. A third pipe 14 is connected to reactor 1, with its inlet end connected to a gaseous hydrogen supply system. A second regulating valve 141 for controlling the gaseous hydrogen flow rate is installed on the third pipe 14. The outlet ends of both the third pipe 14 and the second pipe 132 extend into reactor 1 and connect to the distributor.

[0031] Preheated aldehyde material is introduced into the distributor through the second pipe 132, and gaseous hydrogen is introduced into the distributor through the third pipe 14. The aldehyde material and gaseous hydrogen are dispersed and mixed evenly in the distributor to form a reaction liquid. After flowing out of the distributor, the reaction liquid flows through the first catalyst bed 11. The aldehyde material in the reaction liquid is hydrogenated and catalytically converted into an alcohol. The hydrogen reacts with the aldehyde material, generating heat of reaction, which causes the temperature of the reaction liquid to rise.

[0032] In this embodiment, a pressure transmitter 3 for detecting internal pressure is installed on reactor 1. The data output terminal of pressure transmitter 3 is connected to the control system signal. The control system is connected to the second regulating valve 141. The control system can adjust the opening of the second regulating valve 141 according to the internal pressure data of reactor 1 to regulate the amount of gaseous hydrogen replenishment.

[0033] After flowing out of the first catalyst bed 11, the reaction liquid comes into contact with the interlayer heat exchange coil 13. Since the interlayer heat exchange coil 13 contains aldehyde material at a lower temperature, heat exchange occurs between the aldehyde material and the reaction liquid. The aldehyde material absorbs heat from the reaction liquid and heats up, achieving a preheating effect. The reaction liquid absorbs the cold energy from the aldehyde material and cools down, completing a primary quench. By setting up the interlayer heat exchange coil 13, the preheating process of the aldehyde material and the primary quench process of the reaction liquid can be concentrated within the interlayer heat exchange coil 13 built into the reactor 1, shortening the process and reducing the energy consumption caused by additional quench and preheating equipment.

[0034] In this embodiment, in order to ensure that the reaction liquid flowing out of the first catalyst bed 11 is in full contact with the interlayer heat exchange coil 13 and to prevent the reaction liquid from flowing through the interlayer heat exchange coil 13 locally, a porous distribution plate 2 is installed inside the reactor 1, and the porous distribution plate 2 is located between the first catalyst bed 11 and the interlayer heat exchange coil 13.

[0035] The porous distribution plate 2 has several through holes with a diameter of 5 mm. These through holes are arranged in an equilateral triangle on the surface of the porous distribution plate 2, and the center-to-center distance between the through holes is 12-15 mm (preferably 13 mm). After the reaction liquid flows out from the first catalyst bed 11, it is guided by the through holes on the porous distribution plate 2, which allows the reaction liquid to flow out evenly and make sufficient contact with the interlayer heat exchange coil 13. This prevents the reaction liquid from being insufficiently cooled in some areas due to insufficient contact with the interlayer heat exchange coil 13.

[0036] Reference Figure 1 A fourth pipe 15 is installed at the bottom of reactor 1, and the outlet end of the fourth pipe 15 is connected to a fifth pipe 16 and a sixth pipe 17. A circulating pump 151 and a heat transfer steam drum 152 are installed sequentially on the fourth pipe 15 along the flow direction of the reaction liquid.

[0037] After passing through the interlayer heat exchange coil 13, the reaction liquid flows through the second catalyst bed, where it can further complete the hydrogenation reaction of aldehyde materials to produce alcohol. After passing through the second catalyst bed, the reaction liquid heats up due to the heat of reaction. The circulating pump 151 extracts the reaction liquid from the reactor 1, and the reaction liquid flows through the heat transfer steam drum 152 to exchange heat and achieve secondary cooling.

[0038] After the reaction liquid flows out through the fourth pipe 15, it is split into two streams by the fifth pipe 16 and the sixth pipe 17, and a third regulating valve 171 for controlling the flow rate of the reaction liquid is installed on the sixth pipe 17. In this embodiment, the outlet end of the fifth pipe 16 extends into the interior of the reactor 1, and the outlet end of the fifth pipe 16 is located above the first catalyst bed 11; a central tube 18 is installed axially in the middle of the second catalyst bed 12, the outlet end of the sixth pipe 17 extends into the reactor 1 and communicates with the inlet end of the central tube 18, the outlet end of the central tube 18 extends out of the reactor 1, and the central tube 18 is filled with the third catalyst bed 181.

[0039] The gaseous hydrogen supply system is also connected to a seventh pipe 19, the outlet of which is connected to a sixth pipe 17. A fourth regulating valve 191 is installed on the seventh pipe 19 to control the flow rate of the replenished gaseous hydrogen. As the reaction liquid flows from the sixth pipe 17 to the central tube 18, gaseous hydrogen can be replenished through the seventh pipe 19. When the reaction liquid replenished with gaseous hydrogen flows through the central tube 18, it can be further catalyzed by the third catalyst bed 181 inside the central tube 18 to complete the hydrogenation reaction of the aldehyde material to produce an alcohol. The final alcohol material is sent to the subsequent distillation system through the central tube 18.

[0040] Another stream of reaction liquid flowing out from the fifth pipe 16 flows back into reactor 1 and circulates through the first catalyst bed 11, the porous distribution plate 2, the second catalyst bed 12, and the third catalyst bed 181 to recycle the reaction.

[0041] It should be noted that in this embodiment, the third catalyst bed 181 is filled with a different material than the first and second catalyst beds. The third catalyst bed 181 uses a nickel-based catalyst.

[0042] By using copper-based catalysts in the first and second catalyst beds and nickel-based catalysts in the third catalyst bed, the full hydrogenation of unsaturated aldehydes can be achieved through the synergistic effect of the two catalyst materials.

[0043] By using a three-stage catalyst bed (11, 12, and 181), the height of the catalyst bed can be reduced, thus mitigating the risk of reaction liquid channeling. A porous distribution plate (2) evenly distributes the reaction liquid, and interlayer heat exchange coils (13) and heat transfer steam drums (152) facilitate cold-quench heat exchange between the first and second catalyst beds (11 and 12), and between the second and third catalyst beds (12 and 181). This results in a more uniform catalyst bed temperature, reduces the occurrence of side reactions, and improves reaction selectivity.

[0044] By using intermittent heat exchange in conjunction with cold quenching of feed and setting an interlayer heat exchange coil 13 between the first catalyst bed 11 and the second catalyst bed 12, some of the reaction heat can be removed through the interlayer heat exchange coil 13, which can reduce the circulation volume of the reaction liquid, reduce the energy consumption of the hydrogenation reaction, and at the same time reduce the energy consumption of preheating aldehyde materials.

[0045] Furthermore, by filling the third catalyst bed 181 inside the central tube 18, which is located at the center of the second catalyst bed 12, the height of the catalyst bed can be further shortened, making the internal structure of the catalyst bed more compact.

[0046] In this embodiment, the reactor reaction method includes the following steps: Step S1: The aldehyde material from the upper stage is preheated by the reaction liquid passing through the first catalyst bed, so that the temperature of the aldehyde material is raised to 130-150°C. The gaseous hydrogen and the preheated aldehyde material are transported to the distributor built into the reactor. The gaseous hydrogen and aldehyde material are dispersed and uniformly mixed by the distributor to form a reaction liquid. Step S2: The reaction liquid passes through the first catalyst bed built into the reactor, and the reaction liquid passing through the first catalyst bed is subjected to a cold quench treatment by the aldehyde material in the upper section. Step S3: The reaction liquid passes through the second catalyst bed built into the reactor. The reaction liquid that has passed through the second catalyst bed is extracted from the reactor by a circulation pump, and the reaction liquid that has passed through the second catalyst bed is subjected to a second cooling treatment by a heat transfer steam drum. Step S4: The reaction liquid that has undergone secondary quenching in step S3 is divided into two streams. One stream of reaction liquid is replenished with gaseous hydrogen and then transported to the third catalyst bed in the central tube. The alcohol product passing through the third catalyst bed in the central tube is transported to the subsequent distillation system through the central tube. The other stream of reaction liquid is returned to the reactor, and steps S2 and S3 are repeated.

[0047] Step S1 includes the following steps: Step S11: The aldehyde material from the upper section is fed into the interlayer heat exchange coil through the first pipeline. The reaction liquid that has passed through the first catalyst bed exchanges heat with the aldehyde material through the interlayer heat exchange coil. The aldehyde material absorbs the heat of reaction from the reaction liquid and its temperature rises. Step S12: The preheated aldehyde material is transported to the distributor built into the reactor through the second pipeline. The temperature of the aldehyde material flowing in the second pipeline is obtained by the temperature transmitter. The opening of the first regulating valve on the first pipeline is adjusted by the control system according to the temperature of the aldehyde material flowing in the second pipeline, so that the temperature range of the aldehyde material output by the interlayer heat exchange coil is maintained at 130-150℃. Step S13: Gas-phase hydrogen is transported to the distributor in step S12 through the third pipeline. The internal pressure data of the reactor is obtained through the pressure transmitter. The opening of the second regulating valve on the third pipeline is adjusted by the control system according to the internal pressure data of the reactor so that the internal pressure of the reactor is maintained at 2.0 to 4.0 MPaG. Step S14: The gaseous hydrogen and aldehyde material are fully dispersed and mixed using a distributor to prepare a reaction solution.

[0048] Step S2 includes the following steps: Step S21: The reaction liquid passing through the first catalyst bed is uniformly distributed through the porous distribution disk below the first catalyst bed, so that the reaction liquid passing through the first catalyst bed flows out evenly. Step S22: The reaction liquid after uniform distribution is subjected to cooling treatment through the interlayer heat exchange coil through which the aldehyde material from the upper section flows.

[0049] Step S4 includes the following steps: Step S41: The reaction liquid that has passed through the second catalyst bed and the heat transfer steam drum is diverted through the sixth pipe and transported to the central pipe. The gaseous hydrogen required for alcohol production is replenished to the reaction liquid in the sixth pipe through the seventh pipe. The other diverted reaction liquid is returned to the reactor through the fifth pipe, and steps S2 and S3 are repeated. Step S42: Catalyze the reaction liquid transported in the sixth pipeline through the third catalyst bed filled in the central tube; Step S43: The alcohol product that has passed through the third catalyst bed is transported to the subsequent distillation system through the central tube.

[0050] Example 2

[0051] In this embodiment, the control system controls the flow rate of the first regulating valve based on preset preheating temperature, feed temperature, discharge temperature, and specific heat capacity of the aldehyde material. The calculation formula for the flow rate control of the first regulating valve by the control system is as follows: ; ; ; in, This indicates the actual flow rate of aldehyde material in the interlayer heat exchange coil during the current control cycle, expressed in kg / s. is the specific heat capacity of aldehyde materials, expressed in J / (kg*K); The preset preheating temperature, in °C; The initial temperature of the aldehyde material flowing into the interlayer heat exchange coil via the first pipe, in °C; This is the estimated heat flux after low-pass filtering for the current control cycle; The estimated heat flux after low-pass filtering in the previous control cycle; This is the estimated heat flow value for the current control cycle; The temperature of the preheated aldehyde material flowing out of the second pipeline during the current control cycle is expressed in °C. This indicates the flow rate value for the next control cycle; is the time constant of the low-pass filter function, in seconds; This is the control period of the low-pass filter function.

[0052] For interlayer heat exchange coils, when the system is in steady state, the estimated current actual heat flow can be calculated based on the heat balance data of the aldehyde material flowing through the interlayer heat exchange coils, the specific heat capacity of the aldehyde material, the temperature of the aldehyde material before preheating, and the temperature of the aldehyde material after preheating. ; through the set preheated temperature Compared with the current estimated actual heat flow The result after low-pass filtering The flow rate of aldehyde material in the interlayer heat exchange coil can be calculated for the next control cycle. .

[0053] It should be noted that, in this embodiment, the current actual heat flow is estimated. Low-pass filtering can preserve the true heat change value and smooth the data.

[0054] The above are all preferred embodiments of this application, and thus 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 apparatus suitable for the production of alcohols from short-chain aldehydes, characterized in that, The reactor (1) includes a first catalyst bed (11) and a second catalyst bed (12) filled in the reactor (1). The catalyst composition of the first catalyst bed (11) and the second catalyst bed (12) is the same. The first catalyst bed (11) is located above the second catalyst bed (12). A distributor is installed in the reactor (1) and the distributor is set directly above the first catalyst bed (11). The reactor (1) is equipped with an interlayer heat exchange coil (13). The inlet of the interlayer heat exchange coil (13) is connected to a first pipe (131) for supplying aldehyde material from the upper section. A first regulating valve (133) for regulating the aldehyde material is installed on the first pipe (131). The outlet of the interlayer heat exchange coil (13) is connected to a second pipe (132) for conveying the preheated aldehyde material. The outlet end of the second pipe (132) extends into the reactor (1) and is connected to a distributor. The reactor (1) is connected to a third pipe (14), the inlet end of the third pipe (14) is connected to a gaseous hydrogen supply system, the outlet end of the third pipe (14) extends into the reactor (1) and is connected to a distributor, and a second regulating valve (141) is installed on the third pipe (14). The bottom of the reactor (1) is connected to a fourth pipe (15), and a circulating pump (151) and a heat transfer steam drum (152) are installed on the fourth pipe (15). The circulating pump (151) and the heat transfer steam drum (152) are arranged sequentially along the conveying direction of the reaction liquid, and the outlet end of the fourth pipe (15) is connected to a fifth pipe (16) and a sixth pipe (17). The outlet end of the fifth pipe (16) extends into the interior of the reactor (1) and is connected to the distributor; A central tube (18) is installed axially in the middle of the second catalyst bed (12). The central tube (18) is filled with a third catalyst bed, and the outlet end of the central tube (18) is connected to the subsequent distillation system. The catalyst composition of the third catalyst bed (181) is different from that of the first catalyst bed (11) and the second catalyst bed (12). The outlet end of the sixth pipe (17) extends into the reactor (1) and is connected to the inlet end of the central tube (18). A third regulating valve (171) is installed on the sixth pipe (17). The gaseous hydrogen supply system is connected to a seventh pipe (19), the outlet of which is connected to a sixth pipe (17), and a fourth regulating valve (191) is installed on the seventh pipe (19).

2. The liquid-phase hydrogenation apparatus for producing alcohols from short-chain aldehydes according to claim 1, characterized in that, Both the first catalyst bed (11) and the second catalyst bed (12) are filled with copper-based catalysts, and the bed temperature of the first catalyst bed (11) and the second catalyst bed (12) is 150-190℃.

3. A liquid-phase hydrogenation apparatus for producing alcohols from short-chain aldehydes according to claim 2, characterized in that, The third catalyst bed (181) is filled with a nickel-based catalyst.

4. A liquid-phase hydrogenation apparatus for producing alcohols from short-chain aldehydes according to claim 3, characterized in that, The reactor (1) is equipped with a distribution plate (2), which is located between the first catalyst bed (11) and the interlayer heat exchange coil (13). The distribution plate (2) has several through holes, which are distributed in an equilateral triangle. The diameter of each through hole is 5 mm, and the center distance between the through holes is 12-15 mm.

5. A liquid-phase hydrogenation apparatus for producing alcohols from short-chain aldehydes according to claim 4, characterized in that, The interlayer heat exchange coil (13) consists of multiple sets of coiled smooth tubes, the inner diameter of which is 25mm.

6. A liquid-phase hydrogenation apparatus for producing alcohols from short-chain aldehydes according to claim 5, characterized in that, A temperature transmitter (1321) is installed on the second pipeline (132). The signal output terminal of the temperature transmitter (1321) is connected to the signal input terminal of the control system. The signal output terminal of the control system is connected to the signal input terminal of the first regulating valve (133).

7. A liquid-phase hydrogenation apparatus for producing alcohols from short-chain aldehydes according to claim 6, characterized in that, A pressure transmitter (3) is installed on the reactor (1). The signal output terminal of the pressure transmitter (3) is connected to the signal input terminal of the control system. The signal output terminal of the control system is connected to the signal input terminal of the second regulating valve (141).

8. A liquid-phase hydrogenation apparatus for producing alcohols from short-chain aldehydes according to claim 7, characterized in that, The reaction method in the reactor includes the following steps: Step S1: The aldehyde material from the upper stage is preheated by the reaction liquid passing through the first catalyst bed, so that the temperature of the aldehyde material is raised to 130-150°C. The gaseous hydrogen and the preheated aldehyde material are transported to the distributor built into the reactor. The gaseous hydrogen and aldehyde material are dispersed and uniformly mixed by the distributor to form a reaction liquid. Step S2: After the reaction liquid passes through the first catalyst bed filled with copper-based catalyst at a temperature of 150-190°C, the reaction liquid is evenly distributed through a distribution plate, so that the reaction liquid comes into uniform and sufficient contact with the interlayer heat exchange coil through which the aldehyde material flows. The heat exchange coil between the reaction liquid and the aldehyde material is carried out through the interlayer heat exchange coil, completing the first cooling treatment of the reaction liquid, so that the temperature of the reaction liquid drops to 130-150°C. Step S3: After the reaction liquid passes through the second catalyst bed filled with copper-based catalyst and at a temperature of 150-190°C, the reaction liquid that has passed through the second catalyst bed is extracted from the reactor by a circulating pump, and the reaction liquid that has passed through the second catalyst bed is subjected to a second cooling treatment by a heat transfer steam drum, so that the temperature of the reaction liquid drops to 130-150°C. Step S4: The reaction liquid that underwent secondary quenching in step S3 is split through the fifth and sixth pipes. Part of the reaction liquid is transported to the central pipe through the sixth pipe, so that the reaction liquid passes through the third catalyst bed filled with nickel-based catalyst through the central pipe. The reaction liquid that has passed through the third catalyst bed is then transported to the subsequent distillation system. At the same time, another part of the reaction liquid is transported back to the distributor through the fifth pipe, and steps S2 and S3 are repeated.

9. A liquid-phase hydrogenation apparatus for producing alcohols from short-chain aldehydes according to claim 8, characterized in that, Step S1 includes the following steps: Step S11: The aldehyde material from the upper section is fed into the interlayer heat exchange coil through the first pipeline. The reaction liquid that has passed through the first catalyst bed exchanges heat with the aldehyde material through the interlayer heat exchange coil. The aldehyde material absorbs the heat of reaction from the reaction liquid and its temperature rises. Step S12: The preheated aldehyde material is transported to the distributor built into the reactor through the second pipeline. The temperature of the aldehyde material flowing in the second pipeline is obtained by the temperature transmitter. The opening of the first regulating valve on the first pipeline is adjusted by the control system according to the temperature of the aldehyde material flowing in the second pipeline, so that the temperature range of the aldehyde material output by the interlayer heat exchange coil is maintained at 130-150℃. Step S13: Gas-phase hydrogen is transported to the distributor in step S12 through the third pipeline. The internal pressure data of the reactor is obtained through the pressure transmitter. The opening of the second regulating valve on the third pipeline is adjusted by the control system according to the internal pressure data of the reactor so that the internal pressure of the reactor is maintained at 2.0 to 4.0 MPaG. Step S14: The gaseous hydrogen and aldehyde material are fully dispersed and mixed using a distributor to prepare a reaction solution.

10. A liquid-phase hydrogenation apparatus for producing alcohols from short-chain aldehydes according to claim 9, characterized in that, Step S4 includes the following steps: Step S41: The reaction liquid that has passed through the second catalyst bed and the heat transfer steam drum is diverted through the sixth pipe and transported to the central pipe. The gaseous hydrogen required for alcohol production is replenished to the reaction liquid in the sixth pipe through the seventh pipe. The other diverted reaction liquid is returned to the reactor through the fifth pipe, and steps S2 and S3 are repeated. Step S42: Catalyze the reaction liquid transported in the sixth pipeline through the third catalyst bed filled in the central tube; Step S43: The alcohol product that has passed through the third catalyst bed is transported to the subsequent distillation system through the central tube.

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