A method and apparatus for separating solutions from olefin hydroformylation reactions.

Abstract

This invention provides a method and apparatus for separating a solution from an olefin hydroformylation reaction. The apparatus includes: a stripping tower, N evaporators, a gas-liquid separation tank, a first cooler, and a liquid phase collection tank, where N is an integer greater than or equal to 2. The stripping tower has a first feed inlet, a stripping gas inlet, a first gas phase outlet, and a first liquid phase outlet. The N evaporators are arranged in parallel, and each of the N evaporators has a first liquid phase feed inlet connected to the first liquid phase outlet and a heated stream outlet. The gas-liquid separation tank has a heated stream feed inlet, a second liquid phase outlet, and a second gas phase outlet. The first cooler has a hot end feed inlet and a cooling end outlet. The liquid phase collection tank has a cooling stream feed inlet connected to the cooling end outlet, a third gas phase outlet, and a crude product outlet. This invention helps to improve the catalytic activity of the olefin hydroformylation reaction catalyst and increase the product yield.

Description

Technical Field

[0001] This invention relates to the field of mixture separation, and more specifically to a method and apparatus for separating a hydroformylation reaction solution of an olefin. Background Technology

[0002] The olefin hydroformylation reaction refers to The process of olefin hydroformylation is the reaction of hydrogen with olefins in the presence of a catalyst to produce aliphatic aldehydes with one more carbon atom than the original olefin. The olefin hydroformylation reaction solution generally includes the olefin hydroformylation reaction products (including various normal and isomer aldehydes), unreacted olefins, catalysts, solvents, and other components.

[0003] Existing olefin hydroformylation processes mainly include homogeneous hydroformylation and aqueous hydroformylation. Homogeneous hydroformylation has a wider range of applications, using rhodium catalysts, which exist as complexes dissolved in the olefin hydroformylation reaction solution. The homogeneous hydroformylation process is a homogeneous reaction. Separating the olefin hydroformylation reaction solution yields the olefin hydroformylation products (including various n- and iso-aldehydes) and a catalyst-rich stream. This catalyst-rich stream can be reintroduced into the reactor to participate in the olefin hydroformylation reaction, thus achieving catalyst recycling. The rhodium catalysts used in the hydroformylation of olefins are highly temperature sensitive. For example, organophosphorus carbonyl rhodium catalysts are temperature-sensitive organometallic compounds that are unstable in high-temperature environments and are prone to rhodium agglomeration, thereby reducing the catalyst activity. Rhodium-triphenylphosphine catalysts exhibit catalyst polymerization and deactivation when the temperature exceeds 80°C, and the deactivation rate accelerates significantly when the temperature exceeds 120°C. Furthermore, the product may polymerize to form high-boiling substances, reducing the product yield.

[0004] Existing olefin hydroformylation reaction solution separation systems still primarily consist of a two-stage high- and low-pressure evaporator, an aldehyde absorption tower to collect unreacted components, a syngas stripping and recovery system, a stabilizing tower to remove light components, and an isomer distillation tower to separate mixed aldehydes. This process suffers from problems such as long process length, high investment costs, numerous high-temperature sites, and reduced catalyst lifespan. Furthermore, because the catalyst's normal coordination is easily disrupted during the above separation process, it cannot maintain a high-activity state, leading to decreased catalytic activity during recycling and consequently affecting the reaction rate.

[0005] Maintaining the high activity of the catalyst during the solution separation process of the propylene hydroformylation reaction, and thus ensuring that the catalyst still has high catalytic activity during recycling, is a research hotspot in this field. Summary of the Invention

[0006] This invention provides a method and apparatus for separating olefin hydroformylation reaction solutions, which helps to maintain the high activity of the catalyst during the separation process of propylene hydroformylation reaction solutions.

[0007] This invention provides a separation device for an olefin hydroformylation reaction solution, comprising: a stripping tower, N evaporators, a gas-liquid separation tank, a first cooler, and a liquid phase collection tank, where N is an integer greater than or equal to 2; the stripping tower is provided with a first feed inlet, a stripping gas feed inlet, a first gas phase outlet, and a first liquid phase outlet; the N evaporators are arranged in parallel, and each of the N evaporators is provided with a first liquid phase feed inlet connected to the first liquid phase outlet and a heated stream outlet; the gas-liquid separation tank is provided with a heated stream feed inlet connected to the heated stream outlets of the N evaporators, a second liquid phase outlet, and a second gas phase outlet; the first cooler is provided with a hot end feed inlet connected to the second gas phase outlet and a cooling end outlet; the liquid phase collection tank is provided with a cooling stream feed inlet connected to the cooling end outlet, a third gas phase outlet, and a crude product outlet.

[0008] Optionally, it further includes: a reactor; the reactor is used to carry out an olefin hydroformylation reaction; the outlet of the reactor is connected to the first feed port of the stripping tower, the reactor is also provided with a second feed port, a third feed port and a fourth feed port, the second feed port is connected to the gas outlet of the stripping tower, the third feed port is connected to the second liquid phase outlet of the gas-liquid separator, and the fourth feed port is used to input olefins.

[0009] Optionally, a second cooler is provided between the outlet of the reactor and the first feed inlet of the stripping tower.

[0010] Optionally, it further includes: a cold box for separating hydrogen and carbon monoxide from the syngas; the cold box is provided with a syngas inlet, a hydrogen outlet connected to the stripping gas inlet of the stripping tower, and a carbon monoxide outlet connected to the second inlet of the reactor.

[0011] Optionally, the olefin hydroformylation reaction solution includes one or more of the following: propylene hydroformylation reaction solution, butene hydroformylation reaction solution, pentene hydroformylation reaction solution, hexene hydroformylation reaction solution, and hepten hydroformylation reaction solution.

[0012] This invention provides a method for separating an olefin hydroformylation reaction solution, wherein the separation method is performed using the separation apparatus described above; the separation method includes: 1) introducing the olefin hydroformylation reaction solution and stripping gas into the stripping tower for a first gas-liquid separation to obtain a first gas phase and a first liquid phase; 2) dividing the first liquid phase into N streams, which are then introduced into N evaporators for heating; 3) mixing the heated N streams output from the N evaporators and introducing them into the gas-liquid separation tank for a second gas-liquid separation to obtain a second gas phase and a second liquid phase; 4) cooling the second gas phase in the first cooler and then introducing it into the liquid phase collection tank for a third gas-liquid separation to obtain a third gas phase and a crude olefin hydroformylation reaction product.

[0013] Optionally, before step 1), the method further includes: subjecting the olefin, hydrogen, carbon monoxide, and solvent to a hydroformylation reaction under the action of a catalyst to obtain the olefin hydroformylation reaction solution; wherein the temperature of the hydroformylation reaction is 80~90℃; and / or, before step 1), the method further includes: cooling the olefin hydroformylation reaction solution to a temperature less than or equal to 75℃, preferably less than or equal to 55℃, and then allowing the cooled olefin hydroformylation reaction solution to enter the stripping tower for a first gas-liquid separation to obtain a first gas phase and a first liquid phase.

[0014] Optionally, the catalyst includes a ruthenium catalyst.

[0015] Optionally, the heat load of a single evaporator in the N evaporators accounts for 10% to 90% of the total heat load, preferably 40% to 60%.

[0016] Optionally, the stripping gas includes hydrogen; the volume percentage of hydrogen in the stripping gas is 10% to 100%, preferably 90% to 100%; and / or, the temperature in the stripping tower is 70 to 75°C; and / or, the temperature of the N evaporators is 100 to 120°C.

[0017] This invention provides a method and apparatus for separating olefin hydroformylation reaction solutions. The apparatus utilizes a stripping tower to strip the olefin hydroformylation reaction solution, effectively recovering unreacted olefins and avoiding the catalyst activity degradation caused by high-temperature evaporation for unreacted olefin recovery. Furthermore, by using N evaporators to distribute the heat load during separation, the number of high-temperature heating sites on the catalyst is reduced, decreasing the catalyst's residence time at high temperatures and preventing catalyst deactivation, thus extending catalyst lifespan. Therefore, this invention helps maintain a high catalyst activity during the separation of propylene hydroformylation reaction solutions, ensuring high catalytic activity during recycling and contributing to increased reaction rates and yields of olefin hydroformylation products. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the separation device for the olefin hydroformylation reaction solution in some embodiments;

[0019] Figure 2 This is a schematic diagram of the separation device for the olefin hydroformylation reaction solution in Comparative Example 1.

[0020] Explanation of reference numerals in the attached figures:

[0021] I - Reactor (reaction unit), II - Stripping tower, IIIA - First evaporator, IIIB - Second evaporator, IV - Gas-liquid separator, V - First cooler, VI - Liquid phase collection tank, VII - Cold box, VIII - Separation unit, 1 - Olefin hydroformylation reaction solution, 2 - Cooled olefin hydroformylation reaction solution, 3 - Stripped gas, 4 - First liquid phase, 5 - First gas phase, 6 - One stream in the first liquid phase, 7 - Another stream in the first liquid phase, 8 - One stream after heating, 9 - After heating Another stream, 10-Heated mixed stream, 11-Second liquid phase, 12-Second gas phase, 13-Cooled second gas phase, 14-Third gas phase, 15-Crude product of olefin hydroformylation reaction, 16-Synthesis gas, 17-Carbon monoxide, 18-Carbon monoxide and hydrogen, 19-Olefin, i-First-stage evaporator, ii-First-stage gas-liquid separator, iii-Second-stage evaporator, iv-Second-stage gas-liquid separator, v-Cooler, vi-Liquid phase collection tank, vii-Absorber, viiii-Gas stripping tower. Detailed Implementation

[0022] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below. The specific embodiments listed below are merely descriptions of the principles and features of the present invention, and the examples are only for explaining the present invention and are not intended to limit the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Catalysts for olefin hydroformylation (such as those for propylene hydroformylation) are prone to deactivation at high temperatures. However, existing olefin hydroformylation solution separation systems primarily consist of a two-stage high- and low-pressure evaporator, an aldehyde absorption tower for collecting unreacted components, a syngas stripping and recovery system, a stabilizing tower for removing light components, and an isomer distillation tower for separating mixed aldehydes. This process suffers from problems such as long process duration, high investment costs, numerous high-temperature sites, and reduced catalyst lifetime. The inventors discovered that reducing the number of high-temperature sites and the duration of high-temperature processes in the olefin hydroformylation solution separation process helps ensure that the catalyst maintains high catalytic activity during separation.

[0024] Based on this, embodiments of the present invention provide a separation device for an olefin hydroformylation reaction solution, comprising: a stripping tower, N evaporators, a gas-liquid separation tank, a first cooler, and a liquid phase collection tank, where N is an integer greater than or equal to 2; the stripping tower is provided with a first feed inlet, a stripping gas feed inlet, a first gas phase outlet, and a first liquid phase outlet; the N evaporators are arranged in parallel, and each of the N evaporators is provided with a first liquid phase feed inlet connected to the first liquid phase outlet and a heated stream outlet; the gas-liquid separation tank is provided with a heated stream feed inlet connected to the heated stream outlets of the N evaporators, a second liquid phase outlet, and a second gas phase outlet; the first cooler is provided with a hot end feed inlet connected to the second gas phase outlet and a cooling end outlet; the liquid phase collection tank is provided with a cooling stream feed inlet connected to the cooling end outlet, a third gas phase outlet, and a crude product outlet.

[0025] According to the inventors' research and analysis, by setting up a stripping tower to strip the olefin hydroformylation reaction solution, not only can unreacted olefins be effectively recovered, but the problem of catalyst activity decline that occurs during the recovery of unreacted olefins using high-temperature evaporation technology can also be avoided. Furthermore, by setting up N evaporators to distribute the heat load during the separation process, the number of high-temperature heating sites on the catalyst and the residence time of the catalyst at high temperatures are reduced, preventing catalyst deactivation at high temperatures and extending catalyst life. Therefore, the embodiments of this invention help maintain the high activity of the catalyst during the separation of the propylene hydroformylation reaction solution, thereby ensuring that the catalyst still has high catalytic activity during recycling, which helps to improve the reaction rate and the yield of olefin hydroformylation reaction products. In addition, the embodiments of this invention can also effectively separate unreacted olefins, catalyst, and aldehyde products from the propylene hydroformylation reaction solution.

[0026] Understandably, the first feed inlet of the stripping tower can be used to feed the olefin hydroformylation reaction solution.

[0027] In the stripping tower, under the action of stripping gas, unreacted olefins in the olefin hydroformylation reaction solution are separated and output from the first gas phase outlet; after the unreacted olefins are separated, the remaining liquid phase in the olefin hydroformylation reaction solution is output from the first liquid phase outlet.

[0028] Each of the N evaporators has a first liquid phase inlet connected to the first liquid phase outlet of the stripping tower, as well as a heating stream outlet. In other words, the first liquid phase inlet of each evaporator is connected to the first liquid phase outlet of the stripping tower, and a heating stream outlet is also provided. It can be seen that the N evaporators are arranged in parallel. In practical implementation, the load can be adjusted across a wide range by combining and switching the operation of N evaporators, based on the total load of the separation unit. Specifically, under high load conditions, N evaporators can be operated in parallel simultaneously, which helps to increase the upper limit of the total load of the separation unit while avoiding excessive load on a single evaporator. This reduces the number of high-temperature sites and the duration of high-temperature processes in the propylene hydroformylation reaction solution separation process, helping to ensure that the catalyst maintains high catalytic activity during separation. Under low load conditions, the number of operating evaporators can be reduced, for example, by switching to single-evaporator operation, lowering the lower limit of the total load of the separation unit and achieving smooth adjustment of the total load. This ensures both high processing capacity under high load and lowers the lower limit of the total load of the separation unit, while also preventing the catalyst from residing at high-temperature sites for too long, which could lead to accelerated catalyst deactivation. This helps to ensure that the catalyst maintains high catalytic activity during separation, thus ensuring that the catalyst still has high catalytic activity during recycling, which helps to increase the reaction rate and the yield of olefin hydroformylation reaction products.

[0029] For example, N can be an integer of 2, 3, 4, 5 or 6, preferably 2.

[0030] The aforementioned N evaporators are used to heat the liquid phase output from the stripping tower. After being heated, the liquid phase output from the N evaporators is fed into a gas-liquid separator for gas-liquid separation, thereby separating the gas stream and liquid stream generated after the liquid phase is heated. The gas stream includes olefin hydroformylation reaction products (aldehydes), and the liquid stream includes olefin hydroformylation reaction catalysts (e.g., ruthenium catalysts).

[0031] The gas stream containing the products of the olefin hydroformylation reaction is cooled by the first cooler and then fed into the liquid phase collection tank. In the liquid phase collection tank, a small amount of non-condensable gas in the gas stream containing the products of the olefin hydroformylation reaction is discharged from the third gas phase outlet, and the crude product of the olefin hydroformylation reaction is output from the crude product outlet.

[0032] In some embodiments, the separation apparatus further includes a reactor for carrying out an olefin hydroformylation reaction. The outlet of the reactor is connected to a first feed inlet of a stripping tower. The reactor also has a second feed inlet, a third feed inlet, and a fourth feed inlet. The second feed inlet is connected to the gas outlet of the stripping tower, the third feed inlet is connected to the second liquid phase outlet of a gas-liquid separator, and the fourth feed inlet is used to input olefins.

[0033] This shows that the separation device described above can not only be used to separate various components in the olefin hydroformylation reaction solution, but also to carry out the olefin hydroformylation reaction.

[0034] Furthermore, a second cooler (precooler) is provided between the reactor outlet and the first feed inlet of the stripping tower. This second cooler can be used to cool (precool) the olefin hydroformylation reaction solution output from the reactor outlet, reduce the temperature of the olefin hydroformylation reaction solution, and prevent the catalyst activity from decreasing at high temperatures.

[0035] In addition, the above-mentioned separation device may also include a cold box, which is used to separate hydrogen (hydrogen-rich gas stream) and carbon monoxide (carbon monoxide-rich gas stream) in the synthesis gas; the cold box is provided with a synthesis gas inlet, a hydrogen outlet connected to the stripping gas inlet of the stripping tower, and a carbon monoxide outlet connected to the second feed inlet of the reactor.

[0036] The hydrogen outlet of the cold box is connected to the stripping gas inlet of the stripping tower, allowing hydrogen to enter the stripping tower as stripping gas and participate in the stripping recovery of olefins. Hydrogen as stripping gas can not only effectively recover unreacted olefins, but also pre-activate the catalyst during the stripping process, maintaining its high activity. After the catalyst is reintroduced into the olefin hydroformylation reaction unit, it still maintains high catalytic activity, accelerating the reaction and increasing the yield of the olefin hydroformylation product (aldehyde).

[0037] The separation device of this invention is suitable for separating unreacted olefins, catalyst, and olefin hydroformylation reaction products (aldehydes) from an olefin hydroformylation reaction solution, which helps to ensure the activity of the catalyst.

[0038] The hydroformylation reaction solution for separating olefins may specifically include one or more of the following: propylene hydroformylation reaction solution, butene hydroformylation reaction solution, pentene hydroformylation reaction solution, hexene hydroformylation reaction solution, and hepten hydroformylation reaction solution.

[0039] Taking the propylene hydroformylation reaction solution as an example, the separation device of this embodiment can be used to separate the components in the propylene hydroformylation reaction solution, and can separate unreacted propylene, catalyst (e.g., ruthenium catalyst, homogeneous catalyst), solvent (heavy component), and butyraldehyde from the propylene hydroformylation reaction solution.

[0040] Furthermore, the separation apparatus of this invention may also include a separation unit, which can be used for further separation and purification of crude olefin hydroformylation reaction products (aldehydes).

[0041] like Figure 1As shown, the separation device for the olefin hydroformylation reaction solution in this embodiment of the invention includes a reactor (reaction unit) I, a stripping tower II, a first evaporator IIIA, a second evaporator IIIB, a gas-liquid separation tank IV, a first cooler V, a liquid phase collection tank VI, a cold box VII, and a separation unit VIII.

[0042] This invention provides a method for separating an olefin hydroformylation reaction solution using the aforementioned separation apparatus. The method includes: 1) introducing the olefin hydroformylation reaction solution and stripping gas into a stripping tower for a first gas-liquid separation to obtain a first gas phase and a first liquid phase; 2) dividing the first liquid phase into N streams, which are then heated in N evaporators; 3) mixing the heated N streams from the N evaporators and introducing them into a gas-liquid separation tank for a second gas-liquid separation to obtain a second gas phase and a second liquid phase; 4) cooling the second gas phase in a first cooler and then introducing it into a liquid phase collection tank for a third gas-liquid separation to obtain a third gas phase and a crude olefin hydroformylation reaction product.

[0043] According to the inventors' research and analysis, in the separation method system of this invention, the first gas-liquid separation of the olefin hydroformylation reaction solution in the stripping tower can effectively separate unreacted olefins from the olefin hydroformylation reaction solution, thereby effectively recovering unreacted olefins. This effectively avoids the problem of catalyst activity reduction caused by high-temperature evaporation to recover unreacted olefins. In addition, N evaporators can share the heat load during the separation process, reduce the number of high-temperature heating sites on the catalyst during the separation process, reduce the residence time of the catalyst at high temperatures, avoid catalyst deactivation at high temperatures, and extend catalyst life. Therefore, this invention helps to maintain the high activity state of the catalyst during the separation of the propylene hydroformylation reaction solution, thereby ensuring that the catalyst still has high catalytic activity during recycling, which helps to improve the reaction rate and the yield of olefin hydroformylation reaction products. Furthermore, this invention can also effectively separate unreacted olefins, catalyst and solvent, as well as aldehyde products from the propylene hydroformylation reaction solution.

[0044] In some embodiments, before step 1), the method further includes: subjecting the olefin, hydrogen, carbon monoxide, and solvent to a hydroformylation reaction under the action of a catalyst to obtain an olefin hydroformylation reaction solution; wherein the temperature of the hydroformylation reaction is 80~90°C.

[0045] The olefin hydroformylation reaction solution includes unreacted olefins, catalysts and solvents (heavy components) and olefin hydroformylation reaction products (aldehydes).

[0046] The unreacted olefins mentioned above may include one or more of propylene, butene, pentene, hexene, and heptene; correspondingly, the olefin hydroformylation reaction products (aldehydes) may include one or more of butyraldehyde, pentanaldehyde, hexanal, heptanaldehyde, and octanaldehyde.

[0047] The catalysts mentioned above may include ruthenium catalysts.

[0048] The aforementioned hydrogen (hydrogen-rich gas) and carbon monoxide (carbon monoxide-rich gas) can be obtained by separating syngas in a cold box, or they can be provided by using hydrogen and carbon monoxide in steel cylinders.

[0049] In addition, before step 1), the process includes: cooling the olefin hydroformylation reaction solution to a temperature of less than or equal to 75°C, preferably less than or equal to 55°C, and then allowing the cooled olefin hydroformylation reaction solution to enter a stripping tower for first gas-liquid separation to obtain a first gas phase and a first liquid phase. This helps to reduce the number of high-temperature sites and the time of the high-temperature process during the separation process, and helps to ensure that the catalyst maintains high catalytic activity during the separation process.

[0050] In step 1), the olefin hydroformylation reaction solution and the stripping gas enter a stripping tower for the first gas-liquid separation, thereby obtaining a first gas phase and a first liquid phase containing unreacted olefins. This effectively avoids the problem of reduced catalyst activity caused by high-temperature evaporation to recover unreacted olefins.

[0051] In practice, the first gas phase, which includes unreacted olefins, can be returned to the olefin hydroformylation reaction unit to continue participating in the olefin hydroformylation reaction, thereby realizing the recycling of unreacted olefins.

[0052] In some embodiments, the stripping gas includes hydrogen. It can be used not only for stripping unreacted olefins but also for pre-activating catalysts, maintaining them in a highly active state.

[0053] In the stripping gas, the volume percentage of hydrogen can be 10% to 100%, for example, 10%, 30%, 60%, 90%, 100%, or any combination thereof, preferably 90% to 100%. In addition to hydrogen, the stripping gas may also include carbon monoxide.

[0054] The temperature in the stripping tower can be 70~75℃, which can effectively recover unreacted olefins while avoiding the problem of catalyst activity decreasing at high temperatures.

[0055] In steps 2) and 3), the first liquid phase is divided into N streams, which are then heated in N evaporators. The heated N streams from the N evaporators are mixed and then enter a gas-liquid separator for second gas-liquid separation to obtain the second gas phase and the second liquid phase.

[0056] N evaporators can share the heat load during the separation process, reduce the number of high-temperature heating sites on the catalyst, reduce the residence time of the catalyst at high temperatures, avoid catalyst deactivation at high temperatures, and extend catalyst life. After heating, the N branch streams are mixed and enter the gas-liquid separator for a second gas-liquid separation, which separates the catalyst from the olefin hydroformylation reaction product (aldehyde), resulting in a second gas phase (including the gas phase stream of the olefin hydroformylation reaction product) and a second liquid phase (including the liquid phase stream of the catalyst and solvent).

[0057] Furthermore, the heat load of a single evaporator in the N evaporators can account for 10% to 90% of the total heat load, for example, 10%, 20%, 40%, 50%, 60%, 80%, 90% or any combination thereof, preferably 40% to 60%.

[0058] In addition, the temperature of a single evaporator can be 100~120℃.

[0059] In practice, the second liquid phase (including the liquid stream of catalyst and solvent) can be returned to the olefin hydroformylation reaction unit to continue catalyzing the olefin hydroformylation reaction, thereby achieving catalyst recycling. The separation method of this embodiment helps ensure that the catalyst is in a highly active state. After the catalyst is returned to the olefin hydroformylation reaction unit, it can still maintain high catalytic activity, increase the reaction rate, and thus increase the yield of olefin hydroformylation reaction products.

[0060] In step 4), the second gas phase (including the gas stream of the olefin hydroformylation reaction product) is cooled (cooled down) by the first cooler and then enters the liquid phase collection tank (buffer tank) to undergo the third gas-liquid separation, resulting in the third gas phase (including a small amount of non-condensable gas) and the crude product of the olefin hydroformylation reaction.

[0061] Understandably, the third gas phase is generally discharged from the top of the liquid phase collection tank (buffer tank), while the crude product of the olefin hydroformylation reaction is generally collected from the bottom of the liquid phase collection tank (buffer tank).

[0062] In practice, after the third gas phase (including a small amount of non-condensable gas) is discharged, it can be flared. After the crude product of the olefin hydroformylation reaction is collected, it can be sent to the downstream refining unit for refining.

[0063] The embodiments of the present invention do not impose any particular limitation on the above-mentioned purification process. For example, the crude product of olefin hydroformylation reaction can be further separated into n-butyraldehyde and isobutyraldehyde.

[0064] like Figure 1 As shown, the method for separating the olefin hydroformylation reaction solution according to an embodiment of the present invention includes:

[0065] 1) Olefin 19, carbon monoxide and hydrogen 18 are respectively introduced into reactor (reaction unit) I, and hydroformylation reaction occurs under the action of solvent and catalyst to obtain olefin hydroformylation reaction solution 1; wherein, the temperature of hydroformylation reaction is 80~90℃;

[0066] After the olefin hydroformylation reaction solution 1 is cooled by the second cooler (precooler), the cooled olefin hydroformylation reaction solution 2 is obtained. The cooled olefin hydroformylation reaction solution 2 is fed into the stripping tower II from the top.

[0067] Simultaneously, the synthesis gas 16 is introduced into the cold box VII and separated into hydrogen and carbon monoxide 17. The hydrogen is used as stripping gas 3 and enters the stripping tower II to undergo the first gas-liquid separation, resulting in the first gas phase 5 and the first liquid phase 4.

[0068] In stripping tower II, under the action of stripping gas 3, unreacted olefins (e.g., propylene) are stripped into the first gas phase 5; the first gas phase 5 and carbon monoxide 17 are mixed to form a gas stream, namely carbon monoxide and hydrogen 18, which is returned to the reactor or reaction unit I to react with olefins 19 to produce aldehyde products.

[0069] 2) The first liquid phase 4 collected from the bottom of the stripping tower II is divided into two streams: one stream 6 and another stream 7. These two streams enter the first evaporator IIIA and the second evaporator IIIB for heating, respectively. The heated stream 8 and the heated stream 9 are output from the first evaporator IIIA and the second evaporator IIIB, respectively.

[0070] 3) The heated one stream 8 and the heated other stream 9 are mixed to form the heated mixed stream 10, which then enters the gas-liquid separator IV for the second gas-liquid separation to obtain the second liquid phase 11 containing the catalyst and heavy components and the second gas phase 12 containing aldehyde products. The second liquid phase 11 is returned to the reactor or reaction unit I.

[0071] 4) The second gas phase 12, including the aldehyde product, is cooled (cooled down) by the first cooler V to obtain the cooled second gas phase 13. The cooled second gas phase 13 enters the liquid phase collection tank VI to undergo the third gas-liquid separation. The third gas phase 14 is separated from the top of the liquid phase collection tank VI, and the crude product 15 of the olefin hydroformylation reaction is separated from the bottom of the liquid phase collection tank VI. The crude product 15 of the olefin hydroformylation reaction is sent to the separation unit VIII for purification.

[0072] In the above method, by controlling the continuous input of olefins, carbon monoxide, hydrogen, and solvent into the reaction system, and simultaneously limiting the input amounts of olefins, carbon monoxide, hydrogen, and solvent to be greater than or equal to the output amount of olefin hydroformylation reaction products from the reaction system, the reaction system is continuously carried out, thereby achieving continuous production of olefin hydroformylation reaction products. During this continuous production process, the catalyst output from the reactor is recovered and returned to the reactor to continue catalyzing the olefin hydroformylation reaction, achieving catalyst recycling. In the separation method provided by this invention, the catalyst can maintain high catalytic activity, which helps to increase the olefin hydroformylation reaction rate, thereby increasing the yield of olefin hydroformylation reaction products.

[0073] The solvent in the embodiments of the present invention may include one or more of n-butyraldehyde, isobutyraldehyde, and butyraldehyde polymers, such as single butyraldehyde or mixed butyraldehyde.

[0074] The embodiments of the present invention do not impose any particular limitations on the pressure in the stripping tower and the pressure in the evaporator.

[0075] The present invention will be further described below through specific embodiments and comparative examples. Unless otherwise specified, the reagents, materials and instruments used below are all conventional reagents, materials and instruments, all of which are commercially available, and the reagents and materials involved can also be synthesized by conventional synthetic methods.

[0076] The sources of some raw materials and instruments are as follows:

[0077] The catalysts for the propylene hydroformylation reaction include rhodium-Packard (Aladdin reagent, purity above 98%) and triphenylphosphine co-catalyst (Aladdin reagent, triphenylphosphine purity above 99.0%).

[0078] Butyraldehyde polymer (solvent, butyraldehyde dimer, Macklin reagent):

[0079] Evaporator: Luoyang Kaimisheng Petrochemical Equipment Co., Ltd.;

[0080] Reactor (reaction vessel) (effective volume is 1L, actual usable volume is 100ml): Luoyang Kaimeisheng Petrochemical Equipment Co., Ltd.;

[0081] Air lifting tower: Beijing Tuochuan Scientific Equipment Co., Ltd.

[0082] Example 1

[0083] like Figure 1 As shown (excluding the cold box and separation unit), this embodiment provides a method for separating a propylene hydroformylation reaction solution, including:

[0084] 1) Propylene is fed into reactor (reaction unit) I (effective volume 1L) at a rate of 120g / h, hydrogen-rich gas (90% by volume) at a rate of 64L / h, and carbon monoxide-rich gas (90% by volume) at a rate of 64L / h. Under the action of butyraldehyde polymer (solvent), rhodium-Parker catalyst, and triphenylphosphine co-catalyst, a hydroformylation reaction occurs, yielding a propylene hydroformylation reaction solution. The hydroformylation reaction temperature is 86℃, the pressure gauge pressure inside the reactor is 1700kPa, the mass fraction of rhodium-Parker catalyst in the reactor is 200ppm, and the mass percentage of triphenylphosphine co-catalyst is 10%.

[0085] After the propylene hydroformylation reaction solution is cooled to 75°C by the second cooler (precooler), a cooled propylene hydroformylation reaction solution is obtained. This cooled propylene hydroformylation reaction solution is fed into the stripping tower II from the top. Hydrogen gas is introduced into the stripping tower II as stripping gas 3 and undergoes the first gas-liquid separation to obtain the first gas phase 5 and the first liquid phase 4.

[0086] In stripping tower II, under the action of stripping gas 3, the unreacted propylene is stripped into the first gas phase 5; the first gas phase 5 and carbon monoxide 17 mix to form a gas stream, namely carbon monoxide and hydrogen 18, which is returned to the reactor or reaction unit I to react with propylene to produce butyraldehyde.

[0087] 2) The first liquid phase 4 collected from the bottom of the stripping tower II is divided into two streams: one stream 6 and the other stream 7. These two streams enter the first evaporator IIIA and the second evaporator IIIB for heating, respectively. The heated stream 8 and the heated stream 9 are output from the first evaporator IIIA and the second evaporator IIIB, respectively. The heat load of the first evaporator IIIA and the second evaporator IIIB each accounts for 50% of the total heat load. The temperature of the first evaporator IIIA and the second evaporator IIIB are both 110℃ and the pressure gauge pressure is 120kpa. The temperature of the stripping tower II is 75℃.

[0088] 3) After heating, one branch stream 8 and another branch stream 9 are mixed to form a heated mixed stream 10, which then enters the gas-liquid separator IV for a second gas-liquid separation to obtain a second liquid phase 11 containing butyraldehyde polymer (solvent), catalyst rhodium Parker, and co-catalyst, and a second gas phase 12 containing butyraldehyde. The second liquid phase 11 is returned to the reactor or reaction unit I.

[0089] 4) The second gas phase 12 containing butyraldehyde is cooled (cooled down) by the first cooler V to obtain the cooled second gas phase 13. The cooled second gas phase 13 enters the liquid phase collection tank VI to undergo the third gas-liquid separation. The third gas phase 14 is separated from the top of the liquid phase collection tank VI, and crude butyraldehyde is separated from the bottom of the liquid phase collection tank VI.

[0090] Example 2

[0091] This embodiment is basically the same as Embodiment 1, except that:

[0092] The hydrogen-rich gas contains 95% hydrogen by volume, and the carbon monoxide-rich gas contains 95% carbon monoxide by volume, with other conditions remaining constant.

[0093] Example 3

[0094] This embodiment is basically the same as Embodiment 1, except that:

[0095] The hydrogen-rich gas contains 100% hydrogen by volume, and the carbon monoxide-rich gas contains 100% carbon monoxide by volume, with other conditions remaining unchanged.

[0096] Example 4

[0097] This embodiment is basically the same as Embodiment 1, except that:

[0098] The hydrogen-rich gas contains 85% hydrogen by volume, and the carbon monoxide-rich gas contains 85% carbon monoxide by volume, with other conditions remaining constant.

[0099] Example 5

[0100] This embodiment is basically the same as Embodiment 1, except that:

[0101] The hydrogen-rich gas contains 50% hydrogen by volume, and the carbon monoxide-rich gas contains 50% carbon monoxide by volume, with other conditions remaining unchanged.

[0102] Example 6

[0103] This embodiment is basically the same as Embodiment 1, except that:

[0104] The hydrogen-rich gas contains 100% hydrogen by volume, and the carbon monoxide-rich gas contains 100% carbon monoxide by volume.

[0105] The temperature of the stripping tower is 55℃; other conditions remain unchanged.

[0106] Example 7

[0107] This embodiment is basically the same as Embodiment 1, except that:

[0108] Butene was used to replace propylene, as in Example 7, for the separation of the butene hydroformylation reaction solution;

[0109] The heat loads of the first evaporator IIIA and the second evaporator IIIB account for 10% and 90% of the total heat load, respectively. The temperature of the first evaporator IIIA is 100℃, the temperature of the second evaporator IIIB is 120℃, and the temperature of the stripping tower II is 70℃.

[0110] All other conditions remain unchanged.

[0111] Example 8

[0112] This embodiment is basically the same as Embodiment 1, except that:

[0113] Replacing propylene with pentene, as in Example 7, is used for the separation of the pentene hydroformylation reaction solution;

[0114] The heat loads of the first evaporator IIIA and the second evaporator IIIB account for 40% and 60% of the total heat load, respectively.

[0115] All other conditions remain unchanged.

[0116] Example 9

[0117] This embodiment is basically the same as Embodiment 1, except that:

[0118] Hexene was used instead of propylene, as in Example 7, for the separation of the hexene hydroformylation reaction solution; other conditions remained unchanged.

[0119] Example 10

[0120] This embodiment is basically the same as Embodiment 1, except that:

[0121] Heptene was used instead of propylene, as in Example 7, for the separation of the heptene hydroformylation reaction solution; other conditions remained unchanged.

[0122] Example 11

[0123] This embodiment is basically the same as Embodiment 1, except that:

[0124] The propylene hydroformylation reaction solution was cooled to 55°C by a second cooler (precooler) to obtain a cooled propylene hydroformylation reaction solution; other conditions remained unchanged.

[0125] Comparative Example 1

[0126] like Figure 2 As shown in the product separation unit, this comparative example provides a method for separating a propylene hydroformylation reaction solution, comprising:

[0127] 1) Propylene is fed into a reaction unit (effective volume 1L) at a rate of 120 g / h and synthesis gas (including hydrogen and carbon monoxide in a 1:1 volume ratio) at a rate of 128 L / h. Under the action of butyraldehyde polymer (solvent), rhodium-Parker catalyst, and triphenylphosphine co-catalyst, a hydroformylation reaction solution of propylene is obtained. The hydroformylation reaction temperature is 86℃, the pressure gauge pressure inside the reactor is 1700 kPa, and the mass fraction of rhodium-Parker catalyst in the reaction unit is 200 ppm, while the mass percentage of triphenylphosphine co-catalyst is 10%.

[0128] 2) After the propylene hydroformylation reaction solution is heated in the first-stage evaporator i, it enters the first-stage gas-liquid separator ii for gas-liquid separation to obtain a gas stream and a liquid stream, wherein the gas stream enters the absorption tower vii;

[0129] 3) The liquid stream output from the primary gas-liquid separator ii enters the secondary evaporator iii for heating, and then enters the secondary gas-liquid separator iv for gas-liquid separation. The resulting liquid phase (containing catalyst) and gas phase are obtained. The liquid phase (containing catalyst) is returned to the reaction unit to continue the catalytic reaction, and the gas phase is cooled and enters the liquid phase collection tank vi. The liquid phase collected from the bottom of the liquid phase collection tank vi is fed into the absorption tower vii.

[0130] 4) The liquid stream drawn from the bottom of absorber vii enters stripping tower viii, where propylene is recovered and crude butyraldehyde is obtained.

[0131] Test example

[0132] 1) After running the separation methods of the above examples and comparative examples continuously for 168 hours, test the catalyst activity decay ratio, that is, test the catalyst activity A before the start of the operation and the catalyst activity B after 168 hours of continuous operation. The catalyst activity decay ratio = (AB) / A × 100%;

[0133] The catalyst activity test method includes: taking a 100ml high-pressure reactor, adding 3.000g octene, 0.80g triphenylphosphine and 4.000g butyraldehyde in sequence, sealing it and replacing it with syngas (1.0MPa×4), extracting 2.200g of circulating catalyst under nitrogen and injecting it into the reactor, then purging with syngas at 2.5MPa, setting the heating power to 30%, the heating temperature to 70 degrees, and the heating time (calculated from reaching the set temperature) to 240min, then starting the reaction. The reaction is considered complete when the syngas pressure no longer decreases, and the reaction rate is calculated (as the catalyst activity).

[0134] 2) Calculate the average generation rate of butyraldehyde (or aldehyde) after the separation methods of the above examples and comparative examples have been run continuously for 168 hours, in mol / L / h.

[0135] The amount of butyraldehyde (or aldehyde) produced (in mol) can be determined by Agilent chromatography. The specific determination method includes: injection volume: 0.2 μL; column temperature: 50℃, hold for 4 min, increase to 60℃ at 3℃ / min, increase to 150℃ at 10℃ / min, increase to 230℃ at 20℃ / min, hold for 8 min; injection port temperature: 250℃; septum purge gas flow rate: 3.0 mL / min; column flow rate (N2): 1 mL / min; split injection, split ratio 30:1; detector: 280℃; hydrogen flow rate: 30 mL / min; air flow rate: 400 mL / min; make-up gas flow rate: 25 mL / min.

[0136] The butyraldehyde solvents used in the above determination methods include n-butyraldehyde and isobutyraldehyde (Aladdin reagent, both with a purity of ≥99.5%).

[0137] Test results

[0138] Table 1. Catalyst activity decay ratio and average aldehyde formation rate

[0139]

[0140] Data Analysis:

[0141] Analysis of Examples 1 to 11 and Comparative Example 1 shows that the catalyst activity attenuation ratio obtained by the separation method of the olefin hydroformylation reaction solution according to the embodiments of the present invention is relatively low, and the average formation rate of the product (aldehyde) is relatively high.

[0142] Therefore, it can be demonstrated that the catalyst separated by the separation method of the olefin hydroformylation reaction solution in the embodiments of the present invention can maintain a high activity state during the reaction cycle. After the catalyst is added back to the olefin hydroformylation reaction unit, the catalyst still maintains a high catalytic activity, which can accelerate the reaction and improve the yield of the olefin hydroformylation reaction product (aldehyde).

[0143] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A separation device for an olefin hydroformylation reaction solution, characterized in that, include: The system consists of a stripping tower, N evaporators, a gas-liquid separator, a first cooler, and a liquid phase collection tank, where N is an integer greater than or equal to 2. The stripping tower is provided with a first feed inlet, a stripping gas feed inlet, a first gas phase outlet, and a first liquid phase outlet; The N evaporators are arranged in parallel, and each of the N evaporators is provided with a first liquid phase inlet connected to the first liquid phase outlet and a heating stream outlet; The gas-liquid separator is provided with a heating stream inlet, a second liquid phase outlet, and a second gas phase outlet, which are connected to the heating stream outlets of the N evaporators. The first cooler is provided with a hot end inlet that is connected to the second gas phase outlet and a cooling end outlet; The liquid phase collection tank is equipped with a cooling stream inlet connected to the cooling end outlet, a third gas phase outlet, and a crude product outlet.

2. The separation device according to claim 1, characterized in that, It also includes: a reactor; the reactor is used to carry out the hydroformylation reaction of olefins; the outlet of the reactor is connected to the first feed port of the stripping tower, the reactor is also provided with a second feed port, a third feed port and a fourth feed port, the second feed port is connected to the gas outlet of the stripping tower, the third feed port is connected to the second liquid phase outlet of the gas-liquid separator, and the fourth feed port is used to input olefins.

3. The separation device according to claim 2, characterized in that, A second cooler is provided between the outlet of the reactor and the first inlet of the stripping tower.

4. The separation device according to claim 2 or 3, characterized in that, Also includes: A cold box is used to separate hydrogen and carbon monoxide from the syngas; the cold box is provided with a syngas inlet, a hydrogen outlet connected to the stripping gas inlet of the stripping tower, and a carbon monoxide outlet connected to the second inlet of the reactor.

5. The separation apparatus according to any one of claims 1-4, characterized in that, The olefin hydroformylation reaction solution includes one or more of the following: propylene hydroformylation reaction solution, butene hydroformylation reaction solution, pentene hydroformylation reaction solution, hexene hydroformylation reaction solution, and hepten hydroformylation reaction solution.

6. A method for separating a solution from an olefin hydroformylation reaction, characterized in that, The separation method is performed using the separation apparatus according to any one of claims 1-5; the separation method includes: 1) The olefin hydroformylation reaction solution and stripping gas are introduced into the stripping tower to undergo a first gas-liquid separation, resulting in a first gas phase and a first liquid phase; 2) The first liquid phase is divided into N streams, which enter the N evaporators respectively for heating; 3) The heated N streams output from the N evaporators are mixed and then enter the gas-liquid separator for a second gas-liquid separation to obtain a second gas phase and a second liquid phase; 4) After the second gas phase is cooled by the first cooler, it enters the liquid phase collection tank to undergo third gas-liquid separation, yielding the third gas phase and crude product of olefin hydroformylation reaction.

7. The separation method according to claim 6, characterized in that, Before step 1), the process further includes: subjecting the olefin, hydrogen, carbon monoxide, and solvent to a hydroformylation reaction under the action of a catalyst to obtain the olefin hydroformylation reaction solution; wherein the temperature of the hydroformylation reaction is 80~90℃. And / or, before step 1), the method further includes: cooling the olefin hydroformylation reaction solution to a temperature less than or equal to 75°C, and then allowing the cooled olefin hydroformylation reaction solution to enter the stripping tower for a first gas-liquid separation to obtain a first gas phase and a first liquid phase.

8. The separation method according to claim 7, characterized in that, Before step 1), the method further includes: cooling the olefin hydroformylation reaction solution to a temperature less than or equal to 55°C, and then allowing the cooled olefin hydroformylation reaction solution to enter the stripping tower for first gas-liquid separation to obtain a first gas phase and a first liquid phase.

9. The separation method according to claim 7 or 8, characterized in that, The catalyst includes a ruthenium catalyst.

10. The separation method according to any one of claims 6-9, characterized in that, The heat load of a single evaporator in the N evaporators accounts for 10% to 90% of the total heat load.

11. The separation method according to claim 10, characterized in that, The heat load of a single evaporator in the N evaporators accounts for 40% to 60% of the total heat load.

12. The separation method according to any one of claims 6-11, characterized in that, The stripping gas includes hydrogen; the volume percentage of hydrogen in the stripping gas is 10% to 100%. And / or, the temperature in the stripping tower is 70~75℃; And / or, the temperature of the N evaporators is 100~120℃.

13. The separation method according to any one of claims 12, characterized in that, In the stripping gas, the volume percentage of hydrogen is 90% to 100%.

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