Hydroformylation reaction device, hydroformylation reaction method and application thereof

Abstract

The present application provides a hydroformylation reaction device, a hydroformylation reaction method and application thereof. Under the hydroformylation condition, vinyl acetate and synthesis gas are reacted in a first reaction unit, the obtained liquid phase is cooled and then returned to the first reaction unit, the remaining part is sent to a second reaction unit for continuous reaction with another synthesis gas, the liquid phase obtained by the continuous reaction is sent to a gas-liquid separation unit, the separated synthesis gas is discharged, the liquid phase is sent to a separation unit for separation, the catalyst, the crude product and the solvent are separated, and the catalyst and the solvent are circulated back to the first and second reaction units respectively. The hydroformylation reaction method provided by the present application can control the return amount of the catalyst and the solvent and respectively regulate the catalyst concentration of the two reaction zones, so as to ensure the residence time and the reaction effect.

Description

Technical Field

[0001] This invention belongs to the field of hydroformylation reaction technology, specifically relating to a hydroformylation reaction apparatus, a hydroformylation reaction method, and their applications. Background Technology

[0002] Polypropylene terephthalate (PTT), synthesized from 1,3-propanediol, is a novel polyester material that combines the high performance of polyethylene terephthalate (PET) with the easy processability of polybutylene terephthalate (PBT). Currently mature industrial processes all have their own drawbacks. The acrolein hydration hydrogenation process developed by Evonik (formerly Degussa) 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 is becoming 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] In this process, the hydroformylation of vinyl acetate to prepare aldehydes is the key synthetic step. To improve the conversion rate of raw materials, the reaction generally uses two or more reactors in series. This method allows unconverted raw materials or solutions containing raw materials from the first reaction unit to enter the second reaction unit along with the synthesis gas to continue the reaction, ensuring residence time and improving the overall conversion rate of vinyl acetate. Patents CN102826973, CN86101063, and US5105018 all mention this method, but in these patents, the catalyst is mostly reused in solution form. Patent CN103012089B provides a method for propylene carbonyl synthesis. This method sends the foam component containing catalyst from each reaction unit into a separator. Part of the resulting gas phase component is returned, and the part continues to enter the second reaction unit for reaction. The catalyst foam component in the second reaction unit is then separated into gas phase for venting and liquid phase for reuse. This method requires gas-liquid separation equipment for each reaction unit, increasing equipment investment. Summary of the Invention

[0004] This invention provides a hydroformylation reactor and a hydroformylation reaction method using the same reactor. The technical solution provided by this invention is applicable to continuous hydroformylation processes, wherein the catalyst and solvent are recycled separately. An inert solvent or the product can be used as the solvent. When the product is used as the solvent, separation energy consumption can be further reduced, and the catalyst concentration can be flexibly controlled by adjusting the solvent circulation rate, thus saving separation energy. Furthermore, this invention sends the gas phase obtained from each reaction unit to the same separation unit for processing, reducing the number of devices and simplifying the process flow.

[0005] One objective of this invention is to provide a hydroformylation reaction apparatus, comprising: a first reaction unit, a second reaction unit, a first separation unit, and a second separation unit connected sequentially by pipelines, wherein a liquid phase circulation branch connecting the first reaction unit is provided on the pipeline between the first reaction unit and the second reaction unit, and branches connecting the first reaction unit and the second reaction unit are respectively provided on the first reaction unit and the second reaction unit, and a catalyst circulation pipeline and a solvent circulation pipeline are provided between the second separation unit and the first reaction unit and / or the second reaction unit.

[0006] According to the present invention, in the hydroformylation reaction apparatus:

[0007] The first reaction unit is provided with a raw material inlet, a synthesis gas S1 inlet, and an optional hydrogen inlet; the first reaction unit is provided with a cooling system, preferably a cooling coil;

[0008] The second reaction unit is provided with a synthesis gas S2 inlet and an optional hydrogen inlet; the second reaction unit is provided with a cooling system, preferably a jacketed cooling system; the first reaction unit and the second reaction unit can be various synthesis reactors known in the art, as long as they meet the conditions for hydroformylation reaction;

[0009] The first separation unit is equipped with a non-condensable gas component discharge pipeline and a liquid phase component pipeline connecting to the second separation unit; the first separation unit can be any separator known in the art, as long as it can effectively separate the non-condensable gas component and the liquid phase component;

[0010] The second separation unit is equipped with a crude product discharge pipeline, a catalyst circulation pipeline, and a solvent circulation pipeline. The second separation unit can be a combination of various separation devices known in the art, as long as they can separate the crude product, catalyst, and solvent. The crude product includes 2-acetoxypropanal and 3-acetoxypropanal. The second separation unit is also equipped with an oxidation gas inlet.

[0011] The second objective of this invention is to provide a hydroformylation reaction method, which is implemented on the hydroformylation reaction apparatus provided in the first objective of this invention.

[0012] According to the present invention, the method includes: reacting the raw materials and syngas sequentially in a first reaction unit and a second reaction unit, and then sequentially separating them in a first separation unit and a second separation unit, wherein a portion of the liquid-phase product obtained from the reaction in the first reaction unit is recycled back to the first reaction unit, and the catalyst and solvent separated in the second separation unit are respectively recycled back to the first reaction unit and the second reaction unit. Further, the hydroformylation reaction method specifically includes the following steps:

[0013] 1) Vinyl acetate, synthesis gas S1, catalyst, and solvent are fed into the first reaction unit for contact reaction;

[0014] 2) The gas phase component G1 obtained from the first reaction unit is sent to the first separation unit for processing; the liquid phase component L1 obtained from the first reaction unit is divided into two parts. One part, liquid phase component L1-1, is sent to the second reaction unit to continue to react with the synthesis gas S2, and the other part, liquid phase component L1-2, is recycled back to the first reaction unit.

[0015] 3) The gaseous component G2 obtained from the reaction in the second reaction unit is sent to the first separation unit for processing; the liquid component L2 obtained from the second reaction unit enters the first separation unit, the separated gas G3 is discharged, and the separated liquid component L3 is sent to the second separation unit.

[0016] 4) The oxidizing gas S3 is introduced into the second separation unit to precipitate the catalyst and separate the catalyst and liquid phase. The separated liquid phase is further separated to obtain crude product and solvent. The separated catalyst is recycled to the first reaction unit and the second reaction unit, and the obtained solvent is recycled to the first reaction unit and the second reaction unit.

[0017] According to the present invention, in step 1) of the hydroformylation reaction method:

[0018] The synthesis gas S1 can be any type of synthesis gas available in the art. Preferably, 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 (0.5-5):1, and more preferably (0.5-3):1. In step 1), during continuous industrial production, hydrogen is optionally introduced into the first reaction unit according to the composition of the synthesis gas, in order to adjust the ratio of hydrogen to carbon monoxide in the synthesis gas to be within the above range.

[0019] The feed molar ratio of vinyl acetate to syngas S1 is 1:(1-20), preferably 1:(1-10), wherein the molar amount of syngas S1 is calculated as the total molar amount of hydrogen and carbon monoxide therein.

[0020] The catalyst is selected from at least one of compounds containing the metallic component cobalt, and can be a cobalt compound and / or complex commonly used in the art; preferably, the catalyst is cobalt octacarbonyl.

[0021] The amount of catalyst used, in molar amounts, is 0.5 to 10 mol% of vinyl acetate, preferably 0.5 to 5 mol%.

[0022] The solvent is selected from at least one of aromatic solvents and acyloxy aldehyde compounds, preferably from at least one of toluene, o-dichlorobenzene, and acetoxypropionaldehyde compounds. According to the present invention, the solvent can be an inert medium such as toluene or o-dichlorobenzene, or a solvent containing acetoxypropionaldehyde compounds, such as 3-acetoxypropionaldehyde, or a mixture containing 2-acetoxypropionaldehyde and 3-acetoxypropionaldehyde, wherein the mixture containing 2-acetoxypropionaldehyde and 3-acetoxypropionaldehyde can be directly used as the crude product of the hydroformylation reaction. According to a specific embodiment of the present invention, the solvent is most preferably a solvent containing acetoxypropionaldehyde compounds (3-acetoxypropionaldehyde, or a mixture containing 2-acetoxypropionaldehyde and 3-acetoxypropionaldehyde).

[0023] The catalyst content is 1 to 30 wt%, preferably 10 to 20 wt%, based on the total weight of the catalyst and solvent.

[0024] The reaction conditions of the first reaction unit are: a reaction temperature of 50 to 150°C and a reaction pressure of 0.5 to 8 MPa; preferably, the reaction temperature is 80 to 130°C and the reaction pressure is 1 to 7 MPa.

[0025] According to the present invention, in step 2) of the hydroformylation reaction method:

[0026] In the step of sending the gaseous component G1 obtained from the first reaction unit to the first separation unit for processing, the gaseous component G1 can be sent directly to the first separation unit for processing, or the gaseous component G1 can be cooled first and then separated into gas and liquid, and the separated liquid phase can be sent to the first separation unit for processing. For example, the liquid phase after gas-liquid separation is cooled to 20-80°C and then sent to the first separation unit.

[0027] The liquid phase component L1-2 recycled to the first reaction unit accounts for 10-90% of the liquid phase component L1, preferably 10-50%; preferably, the liquid phase component L1-2 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 L1-2 after cooling is 20-100°C, preferably 40-100°C.

[0028] The syngas S2 can be any type of syngas available in the art. Preferably, 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 (0.5-5):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.

[0029] The feed molar ratio of vinyl acetate to syngas S2 in the liquid phase component L1-1 is 1:(1-20), preferably 1:(1-10), wherein the molar amount of syngas S2 is calculated as the total molar amount of hydrogen and carbon monoxide therein.

[0030] The reaction conditions of the second reaction unit are: a reaction temperature of 50-150°C and a reaction pressure of 0.5-8 MPa. Preferably, the reaction temperature is 80-130°C and the reaction pressure is 1-7 MPa.

[0031] According to the present invention, in step 3) of the hydroformylation reaction method:

[0032] In the step of sending the gaseous component G2 obtained from the second reaction unit to the first separation unit for processing, the gaseous component G2 can be sent directly to the first separation unit for processing, or the gaseous component G2 can be cooled first and then separated into gas and liquid, and the separated liquid phase can be sent to the first separation unit for processing. For example, the liquid phase after gas-liquid separation is cooled to 20-80°C and then sent to the first separation unit.

[0033] The operating conditions of the first separation unit are not particularly limited. Commonly used separation conditions in the art can be adopted, such as flash evaporation at 0.5 to 2.5 MPa, cooling separation at 20 to 80 °C, or a combination thereof. The gas G3 obtained after separation mainly contains unreacted synthesis gas and low-boiling-point byproducts such as acetic acid, ethyl acetate, and ethylene. The liquid phase component L3 mainly contains reaction products 2-acetoxypropanal and 3-acetoxypropanal, catalyst, solvent, etc.

[0034] According to the present invention, in step 4) of the hydroformylation reaction method:

[0035] The oxidizing gas S3 is an oxygen-containing gas atmosphere. Preferably, the oxygen content in the oxidizing gas is 0.5-25 wt%. Specifically, it can be air, oxygen, or a mixture of the above gases. An excess of oxidizing gas is introduced into the second separation unit to precipitate the catalyst and separate it from the product system. The amount of oxidizing gas is not particularly limited, as long as it can completely precipitate and recover the catalyst. For example, the molar ratio of oxidizing gas S3 to catalyst is 1-100, preferably 1-90, wherein the molar amount of oxidizing gas is calculated based on the molar amount of oxygen in it.

[0036] The operation process of the second separation unit is not particularly limited, and commonly used separation methods in the art can be adopted. Specifically, liquid phase component L3 enters the second separation unit, and excess oxidizing gas is introduced to cause the catalyst to precipitate. When the solvent used is an acetoxypropionaldehyde compound, a portion of the liquid phase obtained after filtering the catalyst is directly separated and recycled as solvent to the first and second reaction units, while the other portion is used as the crude product of the hydroformylation reaction. When the solvent used is an aromatic solvent, the liquid phase obtained after filtering the catalyst is further separated by a separation tower to obtain the solvent and the crude product of the hydroformylation reaction. The separated solvent can be partially or completely recycled to the first and second reaction units. The separation tower equipment and operating conditions commonly used in the art can be adopted. The second separation unit can be a separation tower with a top temperature of 80-120°C, a bottom temperature of 90-150°C, a pressure of 10-200 kPa, and 5-40 trays.

[0037] The recycled catalyst is 0.5 to 20 wt% of the total weight of the recycled catalyst and solvent, preferably 1 to 18 wt%, wherein the recycled catalyst is the total amount of catalyst recycled to the first reaction unit and the second reaction unit, and the recycled solvent is the total amount of solvent recycled to the first reaction unit and the second reaction unit.

[0038] The catalyst obtained from the second separation unit is recycled to the first and second reaction units. The ratio of the recycled catalyst is not particularly limited and can be adjusted within a wide range. Preferably, the catalyst recycled to the first reaction unit is 50-99% of the total catalyst obtained from the second separation unit, preferably 60-99%; the catalyst recycled to the second reaction unit is 1-50% of the total catalyst obtained from the second separation unit, preferably 1-40%. The recycled catalyst can be partially or completely returned to the first and second reaction units according to actual needs, and the remaining part is discharged for recovery.

[0039] The solvent obtained from the second separation unit is recycled to the first and second reaction units. The ratio of the recycled solvent is not particularly limited and can be adjusted within a wide range. Preferably, the solvent recycled to the first reaction unit is 50-99% of the total solvent obtained from the second separation unit, preferably 60-99%; the solvent recycled to the second reaction unit is 1-50% of the total solvent obtained from the second separation unit, preferably 1-40%. The recycled solvent can be partially or completely returned to the first and second reaction units according to actual needs, and the remaining part is discharged and recovered.

[0040] A third objective of this invention is to provide the application of the hydroformylation reaction apparatus described in one objective of this invention or the hydroformylation reaction method described in another objective of this invention in the preparation of aldehyde compounds.

[0041] The technical solution provided by this invention is applicable to the continuous industrial production operation of hydroformylation reaction. During the initial reaction, appropriate amounts of catalyst and solvent are added to the first reaction unit. In the continuous production process, the catalyst is precipitated out by introducing excess oxidizing gas in the second separation unit. Then, the catalyst and solvent separated in the second separation unit are adjusted to appropriate circulation ratios and recycled to the first and second reaction units respectively, thereby controlling the catalyst concentration in the two reaction zones and improving the conversion efficiency of the reactants. Therefore, during continuous production, the reactants (vinyl acetate) and syngas are replenished to the first and second reaction units in a timely manner to ensure the residence time of the reactants and the reaction effect.

[0042] The hydroformylation reaction apparatus or method provided by this invention, by setting up multiple reaction units and gas-liquid separation units, rationally arranging the material flow direction, saves energy consumption, increases the yield of raw material vinyl acetate, and realizes the recycling of catalyst and solvent, and is suitable for the continuous industrial production of aldehyde compounds. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of the hydroformylation reaction apparatus used in an embodiment of the present invention.

[0044] Explanation of reference numerals in the attached figures:

[0045] 1-First reaction unit, 2-Second reaction unit, 3-First separation unit, 4-Second separation unit, 5-Oxidation gas S3 pipeline, 6-Crude product discharge pipeline, 7-Synthesis gas S1 pipeline, 8-Raw material pipeline, 9-Hydrogen pipeline, 10-Synthesis gas S2 pipeline, 11-Liquid phase component L1-2 circulation pipeline, 12-Catalyst circulation pipeline, 13-Solvent circulation pipeline. Detailed Implementation

[0046] 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.

[0047] 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.

[0048] The hydroformylation reaction apparatus used in the embodiments of the present invention is as follows: Figure 1As shown, the system includes a first reaction unit 1, a second reaction unit 2, a first separation unit 3, and a second separation unit 4 connected sequentially by pipelines. A liquid-phase circulation branch 11 connecting the first reaction unit 1 and the second reaction unit 2 is provided on the pipeline between the first reaction unit 1 and the second reaction unit 2. A catalyst circulation pipeline 12 and a solvent circulation pipeline 13 are provided between the second separation unit 4 and the first reaction unit 1 and the second reaction unit 2. Specifically, the first reaction unit 1 is provided with a raw material inlet 8, a syngas S1 inlet 7, and a hydrogen inlet 9; the second reaction unit 2 is provided with a syngas S2 inlet and a hydrogen inlet 9; the first separation unit 3 is provided with a non-condensable gas component G3 discharge pipeline and a liquid-phase component L3 pipeline connecting to the second separation unit 4; the second separation unit 4 is provided with a crude product discharge pipeline 6, a catalyst circulation pipeline 12, and a solvent circulation pipeline 13; the second separation unit 4 is also provided with an oxidizing gas inlet 5; the first reaction unit 1 is provided with a gas phase component G1 pipeline connecting to the first separation unit 3; and the second reaction unit 2 is provided with a gas phase component G2 pipeline connecting to the first separation unit 3.

[0049] The following is in conjunction with the appendix Figure 1 The present invention will be further described in detail below:

[0050] 1) Under hydroformylation conditions, vinyl acetate (containing hydroformylation catalyst) 8, optional hydrogen gas 9 and synthesis gas 7 are fed into the first reaction unit 1 for contact reaction, and the gaseous component G1 in the reaction product is sent into the first separation unit 3.

[0051] 2) The product liquid phase L1 in the first reaction unit 1 (including hydroformylation catalyst, reaction products, and unreacted reactants) is divided into two parts. One part, L1-1, is sent to the second reaction unit 2 for reaction, and the other part, L1-2, is recycled back to the first reaction unit 1 as a liquid product to control the temperature of the first reaction unit.

[0052] 3) Part of the liquid phase L1-1 of the first reaction unit 1 reacts fully with optional hydrogen 9 and another syngas S2 in the second reaction unit 2. The gaseous component G2 in the reaction product is sent to the first separation unit 3. The liquid phase L2 of the product in the second reaction unit 2 enters the first separation unit 3. Part of the unreacted syngas G3 in the reaction system is discharged, and the liquid phase L3 in the first separation unit 3 is sent to the second separation unit 4.

[0053] 4) After oxidizing gas is introduced into the second separation unit, the catalyst is separated from the liquid phase. The crude product and the circulating solvent stream are separated from the liquid phase. The catalyst and the circulating solvent are returned to the first reaction unit 1 and the second reaction unit 2 for reuse.

[0054] Example 1

[0055] 2829 kg / h of vinyl acetate, 925.2 kg / h of syngas (with a molar ratio of hydrogen to carbon monoxide of 1.02:1 in the syngas), 139.72 kg / h of cobalt octacarbonyl catalyst, and 617.13 kg / h of circulating solvent (3-acetoxypropionaldehyde) solution were fed into the first reaction unit 1. The molar ratio of syngas to vinyl acetate in the reactor was maintained at approximately 2:1. A portion of the liquid phase L1-2 at the bottom of the reactor in the first reaction unit 1 was cooled to 45°C and returned to the first reaction unit 1. The other portion L1-1 was sent to the second reaction unit 2. The ratio of the liquid phase returned to the first reaction unit 1 to the total liquid phase extracted from the first reaction unit was 0.12.

[0056] Another stream of syngas S2 (in which the molar ratio of hydrogen to carbon monoxide is 1:1) and a portion of the liquid phase L1-1 from the first reaction unit are fed into the second reaction unit 2. The liquid phase is fed at a rate of 4432.29 kg / h and the syngas is fed at a rate of 102.8 kg / h, maintaining the syngas to vinyl acetate feed molar ratio in the second reaction unit 2 at 2:1.

[0057] After the gas phase G1 fed into the first reaction unit and the gas phase G2 fed into the second reaction unit are combined and cooled to 39°C, gas-liquid separation is performed. The separated liquid phase and the product liquid phase L2 of the second reaction unit 2 are fed into the first separation unit 3, where the pressure is reduced to 1.0 MPa for flash evaporation. The unreacted part of the synthesis gas phase G3 is discharged, and the liquid phase L3 is sent into the second separation unit 4 for separation.

[0058] In the second separation unit 4, air at a rate of 100 kg / h is introduced into the liquid phase component L3 obtained from the first separation unit 3. The catalyst and liquid phase are separated by centrifugation. The liquid phase is then separated in the second separation unit 4 (separation tower). The separation tower has 23 trays, operates at a pressure of 20 kPa, and has a reflux ratio of 1. 685.7 kg / h of 3-acetoxypropionaldehyde is collected from the bottom of the tower as a solvent for recycling, and 3647.15 kg / h is collected from the top as the crude product. The collected solvent is partially or entirely returned to the first reaction unit 1 and the second reaction unit 2 as needed, at rates of 617.13 kg / h and 68.57 kg / h respectively. The remaining portion is discharged for recovery. The separated catalyst is partially or entirely returned to the first reaction unit 1 and the second reaction unit 2 as needed, at rates of 139.72 kg / h and 15.52 kg / h respectively. The remaining portion is discharged for recovery.

[0059] The reaction temperature in the first reaction unit 1 and the second reaction unit 2 was 109℃, and the pressure was 6.5MPa. The residence time in the first reaction unit was 60 min, and the residence time in the second reaction unit was 70 min. The conversion rate of vinyl acetate was 99%, and the yield was 89.7%.

[0060] Example 2

[0061] The process flow is the same as in Example 1, except that:

[0062] Vinyl acetate 2829 kg / h, syngas S1 964 kg / h, and catalyst 132.62 kg / h were fed into the first reaction unit 1 using a 657 kg / h solution of the hydroformylation reaction product obtained in the continuous production process as a circulating solvent (containing 2-acetoxypropionaldehyde and 3-acetoxypropionaldehyde). The molar ratio of syngas to vinyl acetate in the reactor was maintained at approximately 2:1. A portion of the liquid phase L1-2 at the bottom of the reactor in the first reaction unit 1 was cooled to 45°C and returned to the first reaction unit 1, while the other portion L1-1 was sent to the second reaction unit 2. The ratio of the liquid phase L1-2 returned to the first reaction unit 1 to the total liquid phase L1 extracted from the first reaction unit was 0.20.

[0063] Another stream of syngas S2 (in which the molar ratio of hydrogen to carbon monoxide is 1:1) and a portion of the liquid phase L1-1 from the first reaction unit 1 are fed into the second reaction unit 2. The flow rate of the liquid phase L1-1 is 4454.9 kg / h, the flow rate of syngas S2 is 107.2 kg / h, and the molar ratio of syngas S2 to vinyl acetate in L1-1 in the second reaction unit 2 is 2.95:1.

[0064] After the gas phase G1 fed into the first reaction unit and the gas phase G2 fed into the second reaction unit are combined and cooled to 39°C, gas-liquid separation is performed. The separated liquid phase and the product liquid phase L2 of the second reaction unit 2 are fed into the first separation unit 3, where the pressure is reduced to 1.0 MPa for flash evaporation. The unreacted part of the synthesis gas phase G3 is discharged, and the liquid phase L3 is sent into the second separation unit 4 for separation.

[0065] In the second separation unit 4, air at a rate of 150 kg / h is introduced into the liquid phase component L3 obtained from the gas-liquid separation unit 3. The catalyst and liquid phase are separated by centrifugation. A portion of the liquid phase, 780 kg / h, is separated and sent to a separation tower to remove light components. The separation tower has 23 trays, operates at a pressure of 0.05 MPa, and has a reflux ratio of 20. 730 kg / h is collected from the bottom of the tower as solvent for recycling, and another portion, 3626.95 kg / h, is collected as crude product. The collected solvent is partially or entirely returned to the first reaction unit 1 and the second reaction unit 2 as needed, at rates of 657 kg / h and 73 kg / h respectively. The remaining portion is discharged for recovery. The separated catalyst is partially or entirely returned to the first reaction unit 1 and the second reaction unit 2 as needed, at rates of 132.61 kg / h and 14.73 kg / h respectively. The remaining portion is discharged for recovery.

[0066] The reaction temperature in the first reaction unit 1 and the second reaction unit 2 was 112℃, and the pressure was 6.0 MPa. The residence time in the first reaction unit was 60 min, and the residence time in the second reaction unit was 70 min. The conversion rate of vinyl acetate was 99%, and the yield was 89.5%.

[0067] Example 3

[0068] 2829 kg / h of vinyl acetate, 934 kg / h of syngas (with a molar ratio of hydrogen to carbon monoxide of 1.16:1 in the syngas), 77.84 kg / h of cobalt octacarbonyl catalyst, and 636.96 kg / h of recycled solvent (3-acetoxypropionaldehyde) solution were fed into the first reaction unit 1. The molar ratio of syngas to vinyl acetate in the reactor was maintained at approximately 2.02:1. A portion of the liquid phase L1-2 at the bottom of the reactor in the first reaction unit 1 was cooled to 45°C and returned to the first reaction unit 1. The other portion L1-1 was sent to the second reaction unit 2. The ratio of the liquid phase returned to the first reaction unit 1 to the total liquid phase extracted from the first reaction unit was 0.50.

[0069] Another stream of syngas S2 (with a molar ratio of hydrogen to carbon monoxide of 1.16:1) and a portion of the liquid phase L1-1 from the first reaction unit are fed into the second reaction unit 2. The flow rate of the liquid phase is 4392.2 kg / h, and the flow rate of the syngas is 103.8 kg / h. The feed molar ratio of syngas to vinyl acetate in the second reaction unit 2 is maintained at 4.96:1.

[0070] After the gas phase G1 fed into the first reaction unit and the gas phase G2 fed into the second reaction unit are combined and cooled to 45°C, gas-liquid separation is performed. The separated liquid phase and the product liquid phase L2 of the second reaction unit 2 are fed into the first separation unit 3, where the pressure is reduced to 1.0 MPa for flash evaporation. The unreacted part of the synthesis gas phase G3 is discharged, and the liquid phase L3 is sent into the second separation unit 4 for separation.

[0071] In the second separation unit 4, air at a rate of 300 kg / h is introduced into the liquid phase component L3 obtained from the first separation unit 3. The catalyst and liquid phase are separated by centrifugation. The liquid phase is then separated in the second separation unit 4 (separation tower). The separation tower has 23 trays, an operating pressure of 20 kPa, and a reflux ratio of 1. 749.37 kg / h of 3-acetoxypropionaldehyde is collected from the bottom of the tower as a solvent for recycling, and 3655.02 kg / h is collected from the top as the crude product. The collected solvent is partially or entirely returned to the first reaction unit 1 and the second reaction unit 2 as needed, at rates of 636.96 kg / h and 112.41 kg / h respectively. The remaining portion is discharged for recovery. The separated catalyst is partially or entirely returned to the first reaction unit 1 and the second reaction unit 2 as needed, at rates of 77.84 kg / h and 13.74 kg / h respectively. The remaining portion is discharged for recovery.

[0072] The reaction temperature in the first reaction unit 1 was 109℃ and the pressure was 6.5 MPa, while the reaction temperature in the second reaction unit 2 was 105℃ and the pressure was 5.5 MPa. The residence time in the first reaction unit was 80 min, and the residence time in the second reaction unit was 90 min. The conversion rate of vinyl acetate was 99%, and the yield was 89.9%.

[0073] 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 hydroformylation reaction, comprising the following steps: 1) Vinyl acetate, syngas (S1), catalyst, and solvent are fed into the first reaction unit for contact reaction; 2) The gas phase component (G1) obtained from the first reaction unit is sent to the first separation unit for processing; the liquid phase component (L1) obtained from the first reaction unit is divided into two parts. One part of the liquid phase component (L1-1) is sent to the second reaction unit to continue to react with the synthesis gas (S2), and the other part of the liquid phase component (L1-2) is recycled back to the first reaction unit. 3) The gaseous component (G2) obtained from the second reaction unit is sent to the first separation unit for processing; the liquid component (L2) obtained from the second reaction unit enters the first separation unit, the separated gas (G3) is discharged, and the separated liquid component (L3) is sent to the second separation unit. 4) The oxidizing gas (S3) is introduced into the second separation unit to precipitate the catalyst and separate the catalyst and liquid phase. The separated liquid phase is further separated to obtain crude product and solvent. The separated catalyst is recycled to the first reaction unit and the second reaction unit, and the obtained solvent is recycled to the first reaction unit and the second reaction unit.

2. The hydroformylation reaction method according to claim 1, characterized in that, The process is carried out in a hydroformylation reaction apparatus, which includes: a first reaction unit, a second reaction unit, a first separation unit, and a second separation unit connected in sequence by pipelines. A liquid phase circulation branch connecting the first reaction unit is provided on the pipeline between the first reaction unit and the second reaction unit. Each of the first and second reaction units is provided with a branch connecting the first separation unit. A catalyst circulation pipeline and a solvent circulation pipeline are provided between the second separation unit and the first and second reaction units. The second separation unit is also provided with an oxidizing gas inlet.

3. The hydroformylation reaction method according to claim 2, characterized in that, The first reaction unit is provided with a raw material inlet, a synthesis gas (S1) inlet, and an optional hydrogen inlet; and / or, The first reaction unit is equipped with a cooling system; and / or, The second reaction unit is provided with a synthesis gas (S2) inlet and an optional hydrogen inlet; and / or, The second reaction unit is equipped with a cooling system.

4. The hydroformylation reaction 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 hydroformylation reaction method according to claim 2, characterized in that, The first separation unit is equipped with a non-condensable gas component discharge pipeline and a liquid phase component pipeline connecting to the second separation unit; and / or, The second separation unit is equipped with a crude product discharge pipeline, a catalyst circulation pipeline, and a solvent circulation pipeline.

6. The hydroformylation reaction method according to claim 1, characterized in that, In step 1): The synthesis gas (S1) is a gaseous component containing hydrogen and carbon monoxide; and / or, The feed molar ratio of vinyl acetate to syngas (S1) is 1:(1~20); and / or, The catalyst is selected from at least one of compounds containing the metallic component cobalt; and / or, The amount of catalyst used, in molar amounts, is 0.5-10 mol% of vinyl acetate; and / or, The solvent is selected from at least one of aromatic solvents and acyloxy aldehyde compounds; and / or, The catalyst content is 1-30 wt% based on the total weight of the catalyst and solvent; 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.

7. The hydroformylation reaction method according to claim 6, characterized in that, In step 1): The molar ratio of hydrogen to carbon monoxide in the synthesis gas (S1) is (0.5~5):1; and / or, The feed molar ratio of vinyl acetate to syngas (S1) is 1:(1~10); and / or, The catalyst is cobalt octacarbonyl; and / or, The amount of catalyst used, in molar amounts, is 0.5-5 mol% of vinyl acetate; and / or, The solvent is selected from at least one of toluene, o-dichlorobenzene, and acetoxypropionaldehyde compounds; and / or, The catalyst content is 10-20 wt% based on the total weight of the catalyst and solvent; and / or, The reaction conditions for the first reaction unit are: a reaction temperature of 80~130 ℃ and a reaction pressure of 1~7 MPa.

8. The hydroformylation reaction method according to claim 1, characterized in that, In step 2): The liquid phase component (L1-2) recycled to the first reaction unit accounts for 10-90% of the liquid phase component (L1); and / or, The synthesis gas (S2) is a gaseous component containing hydrogen and carbon monoxide; and / or, The feed molar ratio of vinyl acetate to syngas (S2) in the liquid phase component (L1-1) is 1:(1~20); 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.

9. The hydroformylation reaction method according to claim 8, characterized in that, In step 2): The liquid phase component (L1-2) recycled to the first reaction unit accounts for 10-50% of the liquid phase component L1; and / or, The molar ratio of hydrogen to carbon monoxide in the syngas (S2) is (0.5~5):1; and / or, The feed molar ratio of vinyl acetate to syngas S2 in the liquid phase component (L1-1) is 1:(1~10); and / or, The reaction conditions for the second reaction unit are: reaction temperature of 80~130 ℃ and reaction pressure of 1~7 MPa.

10. The hydroformylation reaction method according to claim 1, characterized in that, In step 4): The oxidizing gas (S3) is an oxygen-containing gaseous atmosphere; and / or, The molar ratio of the oxidizing gas (S3) to the catalyst is 1~100, wherein the molar amount of the oxidizing gas is expressed as the molar amount of oxygen therein; and / or, The recycled catalyst comprises 0.5–20 wt% of the total weight of the recycled catalyst and solvent; and / or, The catalyst recycled to the first reaction unit is 50-99% of the total catalyst obtained from the second separation unit; and / or, The catalyst recycled to the second reaction unit is 1-50% of the total catalyst obtained from the second separation unit; and / or, The solvent recycled to the first reaction unit is 50-99% of the total solvent obtained from the second separation unit; and / or, The solvent recycled to the second reaction unit is 1 to 50% of the total amount of solvent obtained from the second separation unit.

11. The hydroformylation reaction method according to claim 10, characterized in that, In step 4): The oxygen content in the oxidizing gas (S3) is 0.5~25wt%; and / or, The molar ratio of the oxidizing gas (S3) to the catalyst is 1~90, wherein the molar amount of the oxidizing gas is expressed as the molar amount of oxygen therein; and / or, The recycled catalyst accounts for 1–18 wt% of the total weight of the recycled catalyst and solvent; and / or, The catalyst recycled to the first reaction unit is 60-99% of the total catalyst obtained from the second separation unit; and / or, The catalyst recycled to the second reaction unit is 1-40% of the total catalyst obtained from the second separation unit; and / or, The solvent recycled to the first reaction unit is 60-99% of the total solvent obtained from the second separation unit; and / or, The solvent recycled to the second reaction unit is 1 to 40% of the total amount of solvent obtained from the second separation unit.

12. The application of the hydroformylation reaction method according to any one of claims 1 to 11 in the preparation of aldehyde compounds.

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