A production device, production method and application of acetoxypropanal prepared by a hydroformylation reaction

Abstract

The application provides a production device and method and application of acetoxypropanal prepared by a hydroformylation reaction. Under the hydroformylation condition, ethylene acetate, synthesis gas and a hydroformylation catalyst are fed into a first reaction unit to perform a contact reaction. After partial cooling, a first liquid phase product is recycled, and unreacted synthesis gas, a recycled catalyst solution, a crude product and an unreacted stream are sequentially separated by each separation unit. The unreacted stream is fed into a second reaction unit together with another synthesis gas to continue the contact reaction. After light components are separated from the liquid phase product, the catalyst solution is returned to the front separation unit. The technical scheme provided by the application rationally arranges the material flow direction, saves energy consumption and material consumption, effectively improves the reaction efficiency of the reaction unit, reduces the device scale of the reaction unit, reduces the side reaction and can flexibly control the catalyst proportion of each reaction unit.

Description

Technical Field

[0001] This invention belongs to the field of acetoxypropionaldehyde preparation, specifically relating to a production apparatus, production method and application for preparing acetoxypropionaldehyde by hydroformylation reaction. Background Technology

[0002] Polypropylene terephthalate (PTT) can be synthesized from 1,3-propanediol. PTT is a novel polyester material that combines the high performance of polyethylene terephthalate (PET) with the easy processability of polybutylene terephthalate (PBT). The acrolein hydration hydrogenation process developed by Evonik in Germany uses highly toxic, flammable, and explosive acrolein, which is difficult to store and transport, and is also expensive and hard to obtain. Shell's hydroformylation of ethylene oxide (EO) requires high-pressure equipment, is technically challenging, has a complex catalytic system, is demanding and unstable, and the reaction is difficult to control. DuPont's bio-enzyme catalysis method suffers from low production efficiency and complex purification processes. Therefore, processes for synthesizing propylene glycol and hydroxypropionic acid compounds using vinyl acetate hydroformylation as a key step have been extensively studied in recent years, and the preparation technology of its catalysts has become increasingly mature. In this process, vinyl acetate is first hydroformylated to produce the intermediate product acetoxypropanal, then hydrogenated to produce acetoxypropanol, and then hydrolyzed to obtain 1,3-propanediol and 1,2-propanediol, with acetic acid as a byproduct.

[0003] To improve olefin conversion, a common technical solution is to operate two or more reactors in series, as mentioned in patents CN102826973A, CN86101063A, and US5105018A. This method allows unconverted feedstock or a solution containing feedstock from the first reaction unit to co-enter the second reaction unit with syngas for continued reaction, ensuring residence time and increasing the overall conversion rate of vinyl acetate. These patents typically involve the use of solvents, introducing new substances, requiring precise control of product-solvent separation; simultaneously, the recycling of catalyst solution is not flexible enough; and the reaction unit usually uses two reactors of the same size. Since unconverted feedstock mainly exists in the liquid phase under normal reaction conditions, the reaction liquid stream from the first reaction unit is fed into the second reaction unit, and the reaction stream contains a large amount of acetoxypropionaldehyde product, which reduces the efficiency of the second reaction zone. Summary of the Invention

[0004] This invention provides a production apparatus and method for preparing acetoxypropional via hydroformylation. To improve the efficiency of the second reaction unit, a separation unit is installed between the first and second reaction units to separate the crude product and the stream containing unreacted raw materials. The separated catalyst solution is then recycled back to both the first and second reaction units. This method effectively improves the efficiency of the second reaction unit, reduces its equipment size, minimizes side reactions, and allows for flexible control of the catalyst ratio between the first and second reaction units.

[0005] One objective of this invention is to provide a production apparatus for preparing acetoxypropional via hydroformylation, comprising a first reaction unit, a first gas-liquid separation system, a second reaction unit, and a second gas-liquid separation system connected sequentially by pipelines. The liquid phase outlet of the first reaction unit is connected to the material inlet of the first gas-liquid separation system via a pipeline, and a branch line is provided on this pipeline connecting to the liquid phase inlet of the first reaction unit. The catalyst solution outlet obtained by the first gas-liquid separation system is connected to the first reaction unit and the second reaction unit via pipelines. The catalyst solution outlet obtained by the second gas-liquid separation system is connected to the first gas-liquid separation system via a pipeline. The first gas-liquid separation system includes a first separation unit, a second separation unit, and a third separation unit, and the second gas-liquid separation system includes a fourth separation unit and a fifth separation unit.

[0006] According to the present invention, in the production apparatus for preparing acetoxypropional via hydroformylation reaction:

[0007] The first reaction unit can be any synthesis reactor known in the art. The first reaction unit is provided with a raw material inlet, a synthesis gas inlet, an optional hydrogen inlet, a gas phase outlet, and a liquid phase outlet. The gas phase outlet is connected to the first separation unit by a pipeline, and the liquid phase outlet is connected to the material inlet of the first separation unit by a pipeline, with a branch on the pipeline connecting to the material inlet of the first reaction unit, so that a portion of the liquid phase product is circulated back into the first reaction unit. The first reaction unit is provided with a cooling system, preferably a cooling coil.

[0008] The first separation unit is also provided with a gas phase outlet and a liquid phase outlet, and the liquid phase outlet is connected to the material inlet of the second separation unit by a pipeline; the first separation unit can be a combination of a pressure-reducing gas-liquid separator commonly used in the art;

[0009] The second separation unit is also provided with a liquid phase outlet and a catalyst solution outlet. The liquid phase outlet is connected to the material inlet of the third separation unit by a pipeline, and the catalyst solution outlet is connected to the first reaction unit and the second reaction unit by a pipeline, so that the catalyst solution is sent to the first reaction unit and the second reaction unit respectively for recycling. The second separation unit can adopt various separation equipment or combinations commonly used in the art. For example, a tower separation equipment can be used.

[0010] The third separation unit is also provided with an unreacted stream outlet and an acetoxypropionaldehyde crude product outlet. The unreacted stream outlet is connected to the material inlet of the second reaction unit by a pipeline. The third separation unit can be any separation equipment known in the art. For example, the third separation unit can be a tower separation device.

[0011] The second reaction unit can be any synthesis reactor known in the art. The second reaction unit is also provided with a synthesis gas inlet, a gas phase outlet, a liquid phase outlet, and an optional hydrogen inlet. The gas phase outlet is connected to the first separation unit by a pipeline, and the liquid phase outlet is connected to the material inlet of the fourth separation unit by a pipeline. The second reaction unit is provided with a cooling system, preferably a jacketed cooling system.

[0012] The fourth separation unit is further provided with a gas phase outlet and a liquid phase outlet, and the liquid phase outlet is connected to the material inlet of the fifth separation unit by a pipeline; the fourth separation unit can be various separation devices known in the art, such as a combination of depressurized gas-liquid separators;

[0013] The fifth separation unit is also provided with a light component outlet and a liquid phase outlet. The liquid phase outlet is connected to the material inlet of the second separation unit by a pipeline. The fifth separation unit can be any separation equipment known in the art, such as a tower separation equipment.

[0014] The second objective of this invention is to provide a method for preparing acetoxypropional via hydroformylation, which is implemented on the aforementioned apparatus for preparing acetoxypropional via hydroformylation.

[0015] According to the present invention, the production method for preparing acetoxypropionaldehyde by hydroformylation reaction includes: reacting raw materials, syngas, catalyst, and solvent in a first reaction unit; dividing the resulting liquid product into two parts, one part being recycled back to the first reaction unit, and the other part being sent to a first gas-liquid separation system for separation to obtain crude acetoxypropionaldehyde product, unreacted stream, and catalyst solution; recycling the catalyst solution to the first reaction unit and the second reaction unit; sending the unreacted stream to the second reaction unit for further reaction; and sending the product obtained in the second reaction unit to a second gas-liquid separation system for separation to obtain light components and liquid components.

[0016] Furthermore, the production method specifically includes the following steps:

[0017] 1) Vinyl acetate, catalyst, synthesis gas S1, and solvent are fed into the first reaction unit for contact reaction, and the gas phase G1 obtained after the reaction is sent into the first separation unit.

[0018] 2) The liquid phase component L1 obtained after the reaction in the first reaction unit (including reaction products, unreacted raw materials, catalyst, and solvent) is divided into two parts. One part of the liquid phase L1-1 is sent into the liquid phase inlet of the first reaction unit, and the other part of the liquid phase L1-2 is sent into the first separation unit.

[0019] 3) Liquid phase component L1-2 enters the first separation unit, the separated gas phase G2 is discharged, and liquid phase L2 continues to enter the second separation unit. In the second separation unit, liquid phase L3 and catalyst solution are separated. The catalyst solution is recycled to the first reaction unit and the second reaction unit. Liquid phase L3 is sent to the third separation unit to separate unreacted stream L4 and crude acetoxypropionaldehyde product.

[0020] 4) The unreacted stream L4 and syngas S2 are sent to the second reaction unit for contact reaction, and the gas phase G5 obtained from the reaction is sent to the first separation unit.

[0021] 5) The liquid phase L5 obtained after the reaction in the second reaction unit is sent to the fourth separation unit. The separated gas phase G6 is discharged. The liquid phase L6 continues to enter the fifth separation unit. In the fifth separation unit, the light components and liquid phase L7 are further separated. The liquid phase L7 is sent to the second separation unit. The light components are discharged and recovered.

[0022] According to the present invention, in step 1) of the method for producing acetoxypropional via hydroformylation:

[0023] The synthesis gas S1 can be any type of synthesis gas available in the art. For example, the synthesis gas S1 is a gaseous component containing hydrogen and carbon monoxide. Preferably, the molar ratio of hydrogen to carbon monoxide in the synthesis gas S1 is (0.5-6):1, and more preferably (0.5-2):1. In continuous industrial production, hydrogen can be optionally introduced into the first reaction unit according to the composition of the synthesis gas, to adjust the ratio of hydrogen to carbon monoxide in the synthesis gas within the above range.

[0024] The molar ratio of vinyl acetate to syngas S1 is 1:(1-23), preferably 1:(1-10), wherein the molar amount of syngas S1 is calculated as the total molar amount of hydrogen and carbon monoxide therein.

[0025] The catalyst is selected from at least one of compounds containing the metallic rhodium component, and can be a rhodium compound and / or complex commonly used in the art. The catalyst can be used alone without ligands, co-catalysts, or reaction promoters. Further, the catalyst is preferably L-coordinated rhodium tricarbonyl hydride (HRh(CO)3L). The amount of the catalyst can be within a range commonly used in the art. For example, in molar amounts, the amount of the catalyst is 0.2 to 10 mol% of vinyl acetate, preferably 0.5 to 5 mol%.

[0026] The solvent is an acetoxypropionaldehyde compound, preferably acetoxypropionaldehyde, such as 3-acetoxypropionaldehyde, or a mixture containing 2-acetoxypropionaldehyde and 3-acetoxypropionaldehyde, wherein the mixture containing 2-acetoxypropionaldehyde and 3-acetoxypropionaldehyde can be the crude product of the hydroformylation reaction; according to a specific embodiment of the present invention, the solvent is most preferably a solvent containing an acetoxypropionaldehyde compound (3-acetoxypropionaldehyde, or a mixture containing 2-acetoxypropionaldehyde and 3-acetoxypropionaldehyde); using the product of the vinyl acetate hydroformylation reaction as a solvent can avoid the introduction of other substances, improve the separation efficiency of the product and the catalyst solution, and increase the recovery rate;

[0027] The catalyst and solvent can be added to the reaction system in the form of a catalyst solution, wherein the content of the catalyst can be varied within a wide range. Preferably, based on a total catalyst and solvent content of 100 wt%, the catalyst is 0.5 to 30 wt% of the total catalyst and solvent content, and more preferably 10 to 20 wt%.

[0028] The reaction conditions of the first reaction unit are: reaction temperature of 50-150℃, reaction pressure of 0.5-8MPa, and reaction residence time of 30-180min; preferably, the reaction temperature is 80-130℃, the reaction pressure is 0.5-7.5MPa, and the reaction residence time is 30-120min.

[0029] According to the present invention, in the method for producing acetoxypropional via hydroformylation:

[0030] In step 2), the liquid phase L1-1 recycled to the first reaction unit accounts for 7-90% of the liquid phase L1, preferably 10-50%; preferably, the liquid phase component L1-1 is cooled and then recycled to the first reaction unit to control the reaction temperature of the first reaction unit; further, the temperature of the liquid phase component L1-1 after cooling is 30-95°C, preferably 30-80°C.

[0031] In step 3), the ratio of the catalyst solution obtained from the second separation unit to the first and second reaction units is not particularly limited and can be adjusted within a wide range. Preferably, the catalyst solution recycled to the first reaction unit is 50-99% of the total catalyst solution obtained from the second separation unit, preferably 60-99%; the catalyst solution recycled to the second reaction unit is 1-50% of the total catalyst solution obtained from the second separation unit, preferably 1-40%. In actual production, the catalyst solution can be partially or completely returned to the first and second reaction units as needed, with the remaining portion discharged for recycling.

[0032] The operating conditions of the first separation unit are not particularly limited, and commonly used separation conditions in the art can be adopted, such as flash evaporation at a pressure of 0.5 to 2.5 MPa, cooling separation at 45 to 80°C, or a combination thereof.

[0033] The second separation unit can be any separation equipment or combination known in the art, as long as it can separate the catalyst solution from other liquid phase components. For example, a separation tower can be used, and the operating conditions of the separation tower can be any conditions known in the art. Preferably, the separation conditions of the second separation unit are: top temperature of 80-120°C, bottom temperature of 90-150°C, pressure of 10-201 kPa, number of trays of 5-40, and reflux ratio of 0.1-10.

[0034] The third separation unit can be any separation device or combination known in the art, as long as it can separate the crude acetoxypropionaldehyde product and the stream containing unreacted materials. For example, a separation tower can be used, and the operating conditions of the separation tower can be any conditions known in the art. Preferably, the separation conditions of the third separation unit are: 80-120°C, bottom temperature of 90-150°C, pressure of 10-200 kPa, number of trays of 5-40, and reflux ratio of 0.1-10. The crude acetoxypropionaldehyde product includes 2-acetoxypropionaldehyde and 3-acetoxypropionaldehyde.

[0035] According to the present invention, in step 4) of the method for producing acetoxypropional via hydroformylation:

[0036] The syngas S2 can be any type of syngas available in the art. For example, the syngas S2 is a gaseous component containing hydrogen and carbon monoxide. Preferably, the molar ratio of hydrogen to carbon monoxide in the syngas S2 is (0.5-6):1, and more preferably (0.5-3):1. In the continuous industrial production process, hydrogen is optionally introduced into the second reaction unit according to the composition of the syngas introduced, in order to adjust the ratio of hydrogen to carbon monoxide in the syngas within the above range.

[0037] The molar ratio of the synthesis gas S2 to the vinyl acetate in the unreacted stream L4 is (1-23):1, preferably (1-10):1, wherein the molar amount of the synthesis gas S2 is calculated as the total molar amount of hydrogen and carbon monoxide therein;

[0038] In the second reaction unit, the amount of catalyst used is 0.2 to 20 wt% of vinyl acetate in the unreacted stream L4, preferably 1 to 18 wt%.

[0039] The reaction conditions of the second reaction unit are: reaction temperature of 50-150℃, reaction pressure of 0.5-8MPa, and reaction residence time of 30-180min; preferably, the reaction temperature is 80-130℃, the reaction pressure is 0.5-7.5MPa, and the reaction residence time is 30-120min.

[0040] According to the present invention, in step 5) of the method for producing acetoxypropional via hydroformylation:

[0041] The operating conditions of the fourth separation unit are not particularly limited, and commonly used separation conditions in the art can be adopted, such as flash evaporation at a pressure of 0.5 to 2.5 MPa, cooling separation at 45 to 80°C, or a combination thereof.

[0042] The fifth separation unit can be any separation device or combination known in the art, as long as it can separate the light component from other liquid components. For example, a separation tower can be used, and the operating conditions of the separation tower can be any conditions known in the art. Preferably, the operating conditions of the fifth separation unit are: top temperature of 60-110°C, bottom temperature of 90-150°C, pressure of 10-201 kPa, number of trays of 5-40, and reflux ratio of 0.1-10; the light component mainly contains acetic acid and ethyl acetate.

[0043] The liquid phase components obtained from the fifth separation unit, excluding the light components, are sent to the second separation unit for component separation processing, and then continue with subsequent separation operations and other continuous production processes.

[0044] The third objective of this invention is to provide a production apparatus or method for preparing acetoxypropional via the above-mentioned hydroformylation reaction, and its application in the preparation of acetoxypropional via hydroformylation reaction.

[0045] This invention provides a production apparatus for preparing acetoxypropional via hydroformylation. By setting up multiple reaction units and a gas-liquid separation unit, and rationally arranging the material flow, this method can save material consumption, effectively improve the reaction efficiency of the reaction units, and reduce the size and scale of the reaction unit apparatus. In the production method provided by this invention, the product of the first reaction unit is initially separated to separate unreacted raw materials with increased concentration, which can reduce side reactions and improve the reaction efficiency of the second reaction unit. In addition, in this invention, the catalyst solution obtained from the separation unit is recycled to the first and second reaction units in separate paths. By flexibly adjusting the catalyst ratio in each reaction unit, the yield of the raw material vinyl acetate is improved, and the residence time and reaction effect are guaranteed. Attached Figure Description

[0046] Figure 1 This is a schematic diagram of the hydroformylation reaction apparatus used in an embodiment of the present invention.

[0047] Explanation of reference numerals in the attached figures:

[0048] 1-First reaction unit, 2-Second reaction unit, 3-First separation unit, 4-Second separation unit, 5-Catalyst solution circulation pipeline, 6-Unreacted stream L4 pipeline, 7-Synthesis gas S1 pipeline, 8-Vinyl acetate pipeline, 9-Hydrogen pipeline, 10-Synthesis gas S2 pipeline, 11-Fourth separation unit, 12-Fifth separation unit, 13-Liquid phase component L1-1 circulation pipeline, 14-Third separation unit, 15-Crude product discharge pipeline, 16-Light component discharge pipeline. Detailed Implementation

[0049] The present invention will now be described in detail with reference to specific embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention are still within the scope of protection of the present invention.

[0050] Unless otherwise specified, the raw materials used in the examples and comparative examples are all disclosed in the prior art, such as those that can be directly purchased or prepared according to the preparation methods disclosed in the prior art.

[0051] The production apparatus for preparing acetoxypropional via hydroformylation in this embodiment of the invention is as follows: Figure 1As shown, the system includes a first reaction unit 1, a first separation unit 3, a second separation unit 4, a third separation unit 14, a second reaction unit 2, a fourth separation unit 11, and a fifth separation unit 12, which are connected sequentially by pipelines. The first reaction unit 1 and the second reaction unit 2 are connected to the first separation unit 3 via pipelines. The first reaction unit 1 is equipped with a raw material inlet 8, a synthesis gas S1 inlet 7, a hydrogen inlet 9, a gas phase G1 outlet, and a liquid phase L1 outlet. The gas phase G1 outlet is connected to the first separation unit 3 via a pipeline, and the liquid phase L1 outlet is connected to the material inlet of the first separation unit 3 via a pipeline, with a branch line 13 on this pipeline connecting to the first reaction unit 1 to circulate a portion of the liquid phase product back into the first reaction unit. The first separation unit 3 is also equipped with a gas phase G2 outlet and a liquid phase L2 outlet. The liquid phase L2 outlet is connected to the material inlet of the second separation unit 4 via a pipeline. The second separation unit 4 is also equipped with a liquid phase L3 outlet and a catalyst solution outlet. The liquid phase L3 outlet is connected to the material inlet of the third separation unit 14 via a pipeline, and the catalyst solution outlet 5 is connected to the first reaction unit and the second reaction unit via a pipeline. The third separation unit 14 is also provided with an unreacted stream L4 outlet and an acetoxypropionaldehyde crude product outlet 15. The unreacted stream L4 outlet is connected to the material inlet of the second reaction unit 2 via a pipeline 6. The second reaction unit 2 is also provided with a syngas S2 inlet 10, a gas phase G5 outlet, a liquid phase L5 outlet, and a hydrogen inlet 9. The gas phase G5 outlet is connected to the first separation unit 3 via a pipeline, and the liquid phase L5 outlet is connected to the material inlet of the fourth separation unit 11 via a pipeline. The fourth separation unit 11 is also provided with a gas phase G6 outlet and a liquid phase L6 outlet. The liquid phase L6 outlet is connected to the material inlet of the fifth separation unit 12 via a pipeline. The fifth separation unit 12 is also provided with a light component outlet 16 and a liquid phase L7 outlet. The liquid phase L7 outlet is connected to the material inlet of the second separation unit 4 via a pipeline.

[0052] Example 1

[0053] Vinyl acetate, syngas S1, and catalyst solution (solvent is 3-acetoxypropionaldehyde, the amount of rhodium compound in the solution is 16.58% based on HRh(CO)3L) are fed into the first reaction unit 1. The feed rate of vinyl acetate is 2829 kg / h, the feed rate of catalyst solution is 723.26 kg / h, and the feed rate of syngas S1 is 760 kg / h (the molar ratio of hydrogen to carbon monoxide in the syngas is 1.19:1). The feed molar ratio of syngas S1 to vinyl acetate in the reactor is maintained at approximately 1.67:1. A portion of the liquid phase L1-1 at the bottom of the reactor in the first reaction unit 1 is cooled to 45°C and returned to the first reaction unit 1. The other portion L1-2 is sent to the first separation unit 3. The ratio of the liquid phase L1-1 returned to the first reaction unit 1 to the total liquid phase L1 collected from the bottom of the reactor in the first reaction unit 1 is 0.1.

[0054] In the first separation unit 3, the components including liquid phase components L1-2, gas phase G1, and gas phase G5 are depressurized to 1.0 MPa and then flash-separated. The resulting gas phase G2 is discharged, and the remaining liquid phase component L2 is sent to the second separation unit 4 (separation tower) for further separation. The second separation unit 4 has a top temperature of 97.7℃, a bottom temperature of 123.4℃, a pressure of 30 kPa, and 23 trays. At the top of the tower, a portion of the crude acetoxypropionaldehyde product is refluxed at a reflux ratio of 1, ensuring that the crude acetoxypropionaldehyde product and unreacted vinyl acetate are mainly collected from the top of the tower, with a top recovery rate of 3822.839 kg / h. The catalyst solution 5 is collected from the bottom of the second separation unit 4, with a recovery rate of 841 kg / h. The collected catalyst solution is partially or entirely returned to the first reaction unit 1 and sent to the second reaction unit 2 as catalyst solution, at rates of 723.26 kg / h and 117.74 kg / h respectively. The remaining portion is discharged for recovery.

[0055] The liquid phase L3 collected from the top of the second separation unit 4 is sent to the third separation unit 14 (separation tower). The top temperature of the separation tower in the third separation unit 14 is 53.6℃, ​​the bottom temperature is 103.8℃, the pressure is 30kPa, and the number of trays is 18. Unreacted reactants are refluxed at the top of the tower at a reflux ratio of 8, so that unreacted vinyl acetate and other substances L4 are collected from the top of the tower and sent to the second reaction unit 2 to participate in subsequent reactions, with a recovery rate of 397.4 kg / h. The reaction product acetoxypropionaldehyde is collected from the bottom of the tower, with a recovery rate of 3422.86 kg / h.

[0056] Another stream of syngas S2 (in which the molar ratio of hydrogen to carbon monoxide is 1:1) and the effluent L4 from the top of the third separation unit 14 are fed into the second reaction unit 2. The feed rate of effluent L4 is 397.4 kg / h, and the feed rate of syngas S2 is 131 kg / h. The feed molar ratio of syngas S2 to vinyl acetate in effluent L4 in the second reaction unit 2 is maintained at 3.98:1. The gas phase G5 from the top of the second reaction unit 2 is fed into the first separation unit 3, and the liquid phase L5 from the bottom is fed into the fourth separation unit 11. After being depressurized to 1.0 MPa, the gas phase G6 of the unreacted syngas is discharged, and the liquid phase L6 is sent to the fifth separation unit 12 (separation tower) for further separation.

[0057] The liquid phase component L6 obtained from the fourth separation unit 11 is fed into the fifth separation unit 12 for gas-liquid separation. The fifth separation unit 12 has a top temperature of 86℃, a bottom temperature of 126℃, a pressure of 60 kPa, and 23 trays. A portion of the light component is refluxed at the top of the column at a reflux ratio of 1, resulting in the light component 16 being primarily collected from the top of the column at a collection rate of 207.56 kg / h. The bottom liquid phase L7 is collected from the bottom of the fifth separation unit 12 at a collection rate of 360 kg / h. All of the collected bottom liquid phase L7 is returned to the second separation unit 4 for further separation.

[0058] In the first reaction unit 1, the reaction temperature was 109℃, the pressure was 6.5 MPa, and the reaction residence time was 60 min; in the second reaction unit 2, the reaction temperature was 103℃, the pressure was 5.5 MPa, and the reaction residence time was 80 min. The conversion rate of vinyl acetate was 99%, and the yield was 88.8%.

[0059] Example 2

[0060] The process flow is the same as in Example 1, except that:

[0061] Vinyl acetate, syngas S1, and catalyst solution (solvent is 3-acetoxypropionaldehyde, and the amount of rhodium compound in the solution is 15.52% based on HRh(CO)3L) are fed into the first reaction unit 1. The syngas is fed at a rate of 3100 kg / h and the catalyst solution is fed at a rate of 698.03 kg / h, maintaining a syngas to vinyl acetate feed molar ratio of approximately 1.83:1. A portion of the liquid phase L1-1 at the bottom of the first reaction unit 1 is cooled to 45°C and returned to the first reaction unit 1, while the other portion L1-2 is sent to the first separation unit 3. The ratio of the liquid phase L1-1 returned to the first reaction unit 1 to the total liquid phase L1 collected from the bottom of the first reaction unit 1 is 0.17.

[0062] The liquid phase component L2 obtained from the first separation unit 3 is fed into the second separation unit 4 for separation. The second separation unit 4 has a top temperature of 95.3℃, a bottom temperature of 116.4℃, a pressure of 25 kPa, and 23 trays. A portion of the crude acetoxypropionaldehyde product is refluxed at the top of the column at a reflux ratio of 1, ensuring that the crude acetoxypropionaldehyde product and unreacted vinyl acetate are mainly collected from the top of the column, with a top recovery rate of 4430.38 kg / h. The catalyst solution 5 is collected from the bottom of the second separation unit 4, with a recovery rate of 841 kg / h. The collected catalyst solution is partially or entirely returned to the first reaction unit 1 and fed into the second reaction unit 2 as needed, at rates of 698.03 kg / h and 142.97 kg / h respectively. The remaining portion is discharged for recovery.

[0063] The liquid phase L3 collected from the top of the second separation unit 4 is sent to the third separation unit 14. The separation column in the third separation unit 14 has a top temperature of 59.9℃, a bottom temperature of 97℃, a pressure of 25 kPa, and 18 trays. Unreacted reactants are refluxed at the top of the column at a reflux ratio of 10, resulting in unreacted vinyl acetate and other substances (L4) being collected from the top and sent to the second reaction unit 2 for subsequent reactions. The recovery rate is 491.87 kg / h. The reaction product, acetoxypropionaldehyde, is collected from the bottom of the column at a recovery rate of 3935.68 kg / h.

[0064] Another stream of syngas S2 (in which the molar ratio of hydrogen to carbon monoxide is 1.27:1) and the effluent L4 from the top of the third separation unit 14 are fed into the second reaction unit 2. The feed rate of effluent L4 is 634.84 kg / h, and the feed rate of syngas S2 is 131 kg / h. The feed molar ratio of syngas S2 to vinyl acetate in effluent L4 in the second reaction unit 2 is maintained at 3.94:1. The liquid phase L5 from the bottom of the second reaction unit 2 is fed into the fourth separation unit 11. The unreacted portion of the syngas gas phase G6 is discharged, and the liquid phase L6 is sent into the fifth separation unit 12 (separation tower) for separation.

[0065] The liquid phase component L6 obtained from the fourth separation unit 11 is fed into the fifth separation unit 12 for gas-liquid separation. The fifth separation unit 12 has a top temperature of 59.0℃, a bottom temperature of 89.4℃, a pressure of 25 kPa, and 23 trays. A portion of the light component is refluxed at the top of the column at a reflux ratio of 1, resulting in the light component 16 being primarily collected from the top of the column at a collection rate of 207.56 kg / h. The bottom liquid phase L7 is collected from the bottom of the fifth separation unit 12 at a collection rate of 133.02 kg / h. All of the collected bottom liquid phase L7 is returned to the second separation unit 4 for further separation.

[0066] In the first reaction unit 1, the reaction temperature was 109℃, the pressure was 6.5 MPa, and the reaction residence time was 70 min; in the second reaction unit 2, the reaction temperature was 115℃, the pressure was 7.5 MPa, and the reaction residence time was 90 min. The conversion rate of vinyl acetate was 99%, and the yield was 89%.

[0067] Example 3

[0068] The process flow is the same as in Example 1, except that:

[0069] Vinyl acetate, syngas S1, and catalyst solution (solvent is 3-acetoxypropionaldehyde, the amount of rhodium compound in the solution is 14.84% based on HRh(CO)3L) are fed into the first reaction unit 1. The syngas is fed at a rate of 3100 kg / h and the catalyst solution is fed at a rate of 730.4 kg / h, maintaining a syngas to vinyl acetate feed molar ratio of approximately 1.17:1. A portion of the liquid phase L1-1 at the bottom of the first reaction unit 1 is cooled to 45°C and returned to the first reaction unit 1, while the other portion L1-2 is sent to the first separation unit 3. The ratio of the liquid phase L1-1 returned to the first reaction unit 1 to the total liquid phase L1 collected from the bottom of the first reaction unit 1 is 0.5.

[0070] The liquid phase component L2 obtained from the first separation unit 3 is fed into the second separation unit 4 for separation. The second separation unit 4 has a top temperature of 95.7℃, a bottom temperature of 116.4℃, a pressure of 25 kPa, and 23 trays. A portion of the crude acetoxypropionaldehyde product is refluxed at the top of the column at a reflux ratio of 1, ensuring that the crude acetoxypropionaldehyde product and unreacted vinyl acetate are mainly collected from the top of the column, with a top recovery rate of 4251.89 kg / h. The catalyst solution 5 is collected from the bottom of the second separation unit 4, with a recovery rate of 880 kg / h. The collected catalyst solution is partially or entirely returned to the first reaction unit 1 and fed into the second reaction unit 2 as needed, at rates of 730.4 kg / h and 149.6 kg / h respectively. The remaining portion is discharged for recovery.

[0071] The liquid phase L3 collected from the top of the second separation unit 4 is sent to the third separation unit 14. The top temperature of the separation column in the third separation unit 14 is 62.2℃, the bottom temperature is 96.7℃, the pressure is 25 kPa, and the number of trays is 18. Unreacted reactants are refluxed at the top of the column at a reflux ratio of 10, allowing unreacted vinyl acetate and other substances (L4) to be collected from the top and sent to the second reaction unit 2 for subsequent reactions. The recovery rate is 411.81 kg / h. The reaction product, acetoxypropionaldehyde, is collected from the bottom of the column at a recovery rate of 3837.76 kg / h.

[0072] Another stream of syngas S2 (in which the molar ratio of hydrogen to carbon monoxide is 1.28:1) and the effluent L4 from the top of the third separation unit 14 are fed into the second reaction unit 2. The feed rate of effluent L4 is 561.41 kg / h, and the feed rate of syngas S2 is 131 kg / h. The feed molar ratio of syngas S2 to vinyl acetate in effluent L4 in the second reaction unit 2 is maintained at 6.28:1.

[0073] The liquid phase L5 at the bottom of the second reaction unit 2 is sent to the fourth separation unit 11, the unreacted syngas phase G6 is discharged, and the liquid phase L6 is sent to the fifth separation unit 12 (separation tower) for separation.

[0074] The liquid phase component L6 obtained from the fourth separation unit 11 is fed into the fifth separation unit 12 for gas-liquid separation. The fifth separation unit 12 has a top temperature of 55.1℃, a bottom temperature of 88.0℃, a pressure of 25 kPa, and 23 trays. A portion of the light component is refluxed at the top of the column at a reflux ratio of 1, resulting in the light component 16 being primarily collected from the top of the column at a collection rate of 205.09 kg / h. The bottom liquid phase L7 is collected from the bottom of the fifth separation unit 12 at a collection rate of 300 kg / h. All of the collected bottom liquid phase L7 is returned to the second separation unit 4 for further separation.

[0075] In the first reaction unit 1, the reaction temperature was 101℃, the pressure was 6.5MPa, and the reaction residence time was 50min; in the second reaction unit 2, the reaction temperature was 105℃, the pressure was 6.0MPa, and the reaction residence time was 80min. The conversion rate of vinyl acetate was 99%, and the yield was 89.1%.

[0076] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A method for producing acetoxypropional via hydroformylation reaction, specifically comprising the following steps: 1) Vinyl acetate, catalyst, syngas S1, and solvent are fed into the first reaction unit for contact reaction, and the gas phase G1 obtained after the reaction is fed into the first separation unit; the molar ratio of hydrogen to carbon monoxide in the syngas S1 is (0.5~6):1, and the molar ratio of vinyl acetate to syngas S1 is 1:(1~23). 2) The liquid phase L1 obtained after the reaction in the first reaction unit is divided into two parts. One part, liquid phase L1-1, is sent to the liquid phase inlet of the first reaction unit, and the other part, liquid phase L1-2, is sent to the first separation unit. The liquid phase L1-1 recycled to the first reaction unit accounts for 10~50% of the liquid phase L1. 3) Liquid phase L1-2 enters the first separation unit, the separated gas phase G2 is discharged, and liquid phase L2 continues to enter the second separation unit. In the second separation unit, liquid phase L3 and catalyst solution are separated. The catalyst solution is recycled to the first reaction unit and the second reaction unit. Liquid phase L3 is sent to the third separation unit to separate unreacted stream L4 and crude acetoxypropionaldehyde product. 4) The unreacted stream L4 and syngas S2 are fed into the second reaction unit for contact reaction, and the resulting gas phase G5 is fed into the first separation unit; the molar ratio of hydrogen to carbon monoxide in the syngas S2 is (0.5~6):1; the molar ratio of syngas S2 to vinyl acetate in the unreacted stream L4 is (1~23):

1. 5) The liquid phase L5 obtained after the reaction in the second reaction unit is sent to the fourth separation unit. The separated gas phase G6 is discharged. The liquid phase L6 continues to enter the fifth separation unit. In the fifth separation unit, the light components and liquid phase L7 are further separated. The liquid phase L7 is sent to the second separation unit. The light components are discharged and recovered.

2. The production method according to claim 1, characterized in that, The method for producing acetoxypropional via hydroformylation is implemented in a production apparatus for producing acetoxypropional via hydroformylation. The production apparatus includes a first reaction unit, a first gas-liquid separation system, a second reaction unit, and a second gas-liquid separation system connected sequentially by pipelines. The liquid phase outlet of the first reaction unit is connected to the material inlet of the first gas-liquid separation system via a pipeline, and a branch line is provided on this pipeline connecting to the liquid phase inlet of the first reaction unit. The catalyst solution outlet obtained from the first gas-liquid separation system is connected to the first reaction unit and the second reaction unit via pipelines. The catalyst solution outlet obtained from the second gas-liquid separation system is connected to the first gas-liquid separation system via a pipeline. The first gas-liquid separation system includes a first separation unit, a second separation unit, and a third separation unit. The second gas-liquid separation system includes a fourth separation unit and a fifth separation unit. The separation units are as follows: The first reaction unit is provided with a raw material inlet, a syngas inlet, an optional hydrogen inlet, a gas phase outlet, and a liquid phase outlet. The gas phase outlet is connected to the first separation unit by a pipeline, and the liquid phase outlet is connected to the material inlet of the first separation unit by a pipeline, with a branch line on this pipeline connecting to the material inlet of the first reaction unit. The second reaction unit is also provided with a syngas inlet, a gas phase outlet, a liquid phase outlet, and an optional hydrogen inlet. The gas phase outlet is connected to the first separation unit by a pipeline, and the liquid phase outlet is connected to the material inlet of the fourth separation unit by a pipeline. The second separation unit is provided with a liquid phase outlet and a catalyst solution outlet. The liquid phase outlet is connected to the material inlet of the third separation unit by a pipeline, and the catalyst solution outlet is connected to the first reaction unit and the second reaction unit by a pipeline. The fifth separation unit is also provided with a light component outlet and a liquid phase outlet. The liquid phase outlet is connected to the material inlet of the second separation unit by a pipeline.

3. The production method according to claim 2, characterized in that, The first reaction unit is equipped with a cooling system; and / or, The first separation unit is further provided with a gas phase outlet and a liquid phase outlet, the liquid phase outlet being connected by a pipeline to the material inlet of the second separation unit; and / or, The third separation unit is also equipped with an unreacted stream outlet and an acetoxypropionaldehyde crude product outlet. The unreacted stream outlet is connected to the material inlet of the second reaction unit via a pipeline; and / or, The second reaction unit is equipped with a cooling system; and / or, The fourth separation unit is also provided with a gas phase outlet and a liquid phase outlet, and the liquid phase outlet is connected to the material inlet of the fifth separation unit by a pipeline.

4. The production method according to claim 3, characterized in that, The cooling system of the first reaction unit is a cooling coil; and / or, The cooling system of the second reaction unit is a jacketed cooling system.

5. The production method according to claim 1, characterized by, In step 1): The catalyst is selected from at least one of compounds containing the metallic component rhodium; and / or, The amount of catalyst used, in molar amounts, is 0.3~10 mol% of vinyl acetate; and / or, The solvent is an acetoxypropionaldehyde compound; and / or, Based on a total catalyst and solvent content of 100 wt%, the catalyst comprises 0.5 to 30 wt% of the total catalyst and solvent content; and / or, The reaction conditions for the first reaction unit are: a reaction temperature of 50~150 ℃ and a reaction pressure of 0.5~8 MPa.

6. The production method according to claim 5, characterized by, In step 1): The molar ratio of vinyl acetate to syngas S1 is 1:(1~10); and / or, The catalyst is L-coordinated rhodium tricarbonyl hydride; and / or, The amount of catalyst used, in molar amounts, is 0.5-5 mol% of vinyl acetate; and / or, The solvent is acetoxypropionaldehyde; and / or, Based on a total catalyst and solvent content of 100 wt%, the catalyst comprises 10-20 wt% of the total catalyst and solvent content; and / or, The reaction conditions for the first reaction unit are: a reaction temperature of 80~130 ℃ and a reaction pressure of 0.5~7.5 MPa.

7. The production method according to claim 1, characterized in that, In step 3), the catalyst solution recycled to the first reaction unit is 50-99% of the total amount of catalyst solution obtained from the second separation unit; the catalyst solution recycled to the second reaction unit is 1-50% of the total amount of catalyst solution obtained from the second separation unit.

8. The production method according to claim 7, characterized in that, In step 3), the catalyst solution recycled to the first reaction unit is 60-99% of the total amount of catalyst solution obtained from the second separation unit; the catalyst solution recycled to the second reaction unit is 1-40% of the total amount of catalyst solution obtained from the second separation unit.

9. The production method according to claim 1, characterized by, In step 4): In the second reaction unit, the amount of catalyst used is 0.2~20 wt% of vinyl acetate in the unreacted stream L4; and / or, The reaction conditions for the second reaction unit are: a reaction temperature of 50~150 ℃ and a reaction pressure of 0.5~8 MPa.

10. The production method according to claim 9, characterized by, In step 4): The molar ratio of the synthesis gas S2 to the vinyl acetate in the unreacted stream L4 is (1~10):1; and / or, In the second reaction unit, the amount of catalyst used is 1-18 wt% of vinyl acetate in the unreacted stream L4; and / or, The reaction conditions for the second reaction unit are: a reaction temperature of 80~130 ℃ and a reaction pressure of 0.5~7.5 MPa.

11. The method for preparing acetoxypropional by hydroformylation reaction according to any one of claims 1 to 10, and its application in the preparation of acetoxypropional by hydroformylation reaction.

Images