Production device, production method and application of acetoxypropionaldehyde

Abstract

The invention provides a production device, a production method and application of acetoxypropionaldehyde. The method comprises the following steps: under a hydroformylation condition, feeding vinyl acetate, synthesis gas and a hydroformylation catalyst into a first reaction unit for a contact reaction, cooling part of a first liquid phase product and then circulating, and sequentially separating unreacted synthesis gas, the catalyst, a solvent, a crude product, a light component and an unreacted material flow from the other part of the first liquid phase product through separation units; unreacted material flow and another strand of synthesis gas are fed into a second reaction unit for continuous contact reaction, a liquid-phase product is returned to the separation unit for combined treatment, and the catalyst and the solvent are respectively returned to the reaction units. According to the technical scheme provided by the invention, the material flow direction is reasonably arranged, the energy consumption is saved, the reaction efficiency of the reaction units is effectively improved, the device scale of the reaction units is reduced, side reactions are reduced, and the catalyst proportion of each reaction unit can be flexibly regulated.

Description

Technical Field

[0001] The invention belongs to the technical field of acetoxypropionaldehyde preparation, and specifically relates to a production device, a production method and application of acetoxypropionaldehyde. Background Art

[0002] Polytrimethylene terephthalate (PTT) synthesized from 1,3-propylene glycol is a new polyester material that combines the high performance of polyethylene terephthalate (PET) and the easy processing of polybutylene terephthalate (PBT). The current mature industrial processes all have their own shortcomings. The raw material acrolein for the acrolein hydration hydrogenation process developed by Evonik (formerly Degussa) in Germany is highly toxic, flammable and explosive, difficult to store and transport, and difficult to obtain at a high price. The hydroformylation ethylene oxide (EO) process developed by Shell requires high-pressure equipment, high technical difficulty, complex catalytic system, harsh and unstable process, and difficult to control the reaction. The bio-enzyme catalysis method developed by Du Pont has low production efficiency and complex purification process. Therefore, the process of synthesizing propylene glycol and hydroxypropionic acid compounds with vinyl acetate hydroformylation as the key step has been widely studied in recent years, and the preparation technology of its catalyst has become increasingly mature. In this process, vinyl acetate is first hydroformylated to produce the intermediate product acetoxypropionaldehyde, which is then hydrogenated to produce acetoxypropanol, and then hydrolyzed to produce 1,3-propylene glycol and 1,2-propylene glycol, with acetic acid as a by-product.

[0003] In this process, the preparation of aldehyde by hydroformylation of vinyl acetate is a key synthesis step. In order to improve the conversion rate of olefins, the reaction generally adopts two or more reactors in series. This method allows the unconverted raw materials or the solution containing raw materials in the first reaction unit to enter the second reaction unit together with the synthesis gas to continue the reaction, ensure the residence time, and improve the total conversion rate of vinyl acetate. Patents CN102826973A, CN86101063A, and US5105018A all mention this method. In the above patents, the catalyst is mostly reused in the form of solution, which usually involves the use of solvents. In the present invention, the catalyst and solvent are reused separately, and an inert solvent or the product can be selected as the solvent. When the product is used as the solvent, the complexity of the subsequent separation process can be reduced, the energy consumption can be reduced, and the recovery rate can be improved. In the method provided by the present invention, two reaction units can share a set of separation units, which reduces the number of equipment, reduces the equipment size, and saves investment. Summary of the invention

[0004] The invention provides a production device and a production method of acetoxypropionaldehyde, which adopts a method of recycling a catalyst and a solvent respectively, can select an inert solvent or a product as a solvent, and arrange a separation unit between a first reaction unit and a second reaction unit, separate and treat a liquid phase flow obtained by the first reaction unit, separate unreacted materials for further reaction, and improve reaction efficiency.

[0005] One of the purposes of the present invention is to provide a production device for acetoxypropionaldehyde, comprising a first reaction unit and a second reaction unit, wherein a first separation unit, a second separation unit, and a third separation unit are arranged between the first reaction unit and the second reaction unit, wherein a circulation branch is arranged on the liquid phase outlet pipeline connected to the first separation unit and connected to the liquid phase inlet of the first reaction unit, the second reaction unit is arranged at the liquid phase outlet The pipeline is connected to the first separation unit, and the liquid phase outlet of the second separation unit is arranged with pipelines connected to the first reaction unit and the second reaction unit, respectively.

[0006] According to the present invention, in the production device of acetoxypropionaldehyde:

[0007] The first reaction unit may be any synthesis reactor known in the art. The first reaction unit is further provided with a raw material inlet, a synthesis gas inlet, a gas phase outlet, a liquid phase outlet, and an optional hydrogen inlet. Preferably, in the first reaction unit, the gas phase outlet is connected to the material inlet of the first separation unit by a pipeline. The first reaction unit is also 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 various gas-liquid separators known in the art, as long as it can effectively separate the non-condensable gas component and the liquid phase component, for example, it can be various vacuum flash gas-liquid separation tanks or a combination thereof;

[0009] The second separation unit is also provided with an oxidizing gas inlet for introducing oxidizing gas into the second separation unit to precipitate the catalyst; the second separation unit is also provided with a gas phase outlet, a catalyst outlet, and a solvent outlet; preferably, in the second separation unit, the gas phase outlet is connected to the material inlet of the third separation unit by a pipeline, the catalyst outlet is connected to the first reaction unit and the second reaction unit by a pipeline, and the solvent outlet is connected to the first reaction unit and the second reaction unit by a pipeline; the catalyst pipeline and the solvent pipeline provided in the second separation unit are used to circulate the catalyst and the solvent to the first reaction unit and the second reaction unit respectively, so as to realize the recycling of the catalyst and the solvent; the second separation unit can be a combination of various separation equipment known in the art, for example, it can be a centrifugal separation equipment, a tower separation equipment or the like or a combination thereof;

[0010] The third separation unit is also provided with an unreacted stream outlet, an acetoxypropionaldehyde crude product outlet, and a light component outlet; preferably, in the third separation unit, the unreacted stream outlet is connected to the material inlet of the second reaction unit by a pipeline; the third separation unit can be a combination of various separation equipment known in the art, as long as it can separate the unreacted stream, the crude product, and the light component. For example, the third separation unit can adopt a tower separation equipment, which can be a separation tower or two or more separation towers connected in series;

[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, an optional hydrogen inlet, a gas phase outlet, and a liquid phase outlet. The gas phase outlet and the liquid phase outlet are respectively connected to the first separation unit by pipelines. The second reaction unit is provided with a cooling system, preferably a jacketed cooling system.

[0012] A second object of the present invention is to provide a method for producing acetoxypropionaldehyde, which is implemented on the above-mentioned acetoxypropionaldehyde production device.

[0013] According to the present invention, the production method of acetoxypropionaldehyde comprises: reacting raw materials, synthesis gas, catalyst, and solvent in a first reaction unit, dividing the obtained liquid phase component into two parts, one part is recycled back to the first reaction unit, and the other part is sequentially sent to the first separation unit, the second separation unit, and the third separation unit for separation treatment, the unreacted stream obtained after separation is sent to the second reaction unit for further reaction, and the gas phase component and liquid component obtained by the reaction are respectively sent to the first separation unit. Further, the production method specifically comprises the following steps:

[0014] 1) Vinyl acetate, catalyst, synthesis gas S1, and solvent are fed into a first reaction unit for contact reaction, and the gas phase G1 obtained after the reaction is fed into a first separation unit;

[0015] 2) The liquid component L1 obtained after the reaction in the first reaction unit is divided into two parts, one part of the liquid component L1-1 is recycled to the first reaction unit, and the other part of the liquid component L1-2 is sent to the first separation unit, the separated gas component G2 is discharged, and the liquid component L2 continues to enter the second separation unit;

[0016] 3) In the second separation unit, the gas phase component G3, the catalyst and the solvent are separated under the action of the oxidizing gas; the gas phase component G3 is then sent to the third separation unit to separate the unreacted stream G4, the light component and the crude acetoxypropionaldehyde product; the catalyst separated by the second separation unit is circulated to the first reaction unit and the second reaction unit, and the solvent separated is circulated to the first reaction unit and the second reaction unit;

[0017] 4) The unreacted flow G4 and the synthesis gas S2 are sent to the second reaction unit for contact reaction, and the gas phase component G5 and the liquid phase component L5 obtained by the reaction are respectively sent to the first separation unit.

[0018] According to the present invention, in step 1) of the method for producing acetoxypropionaldehyde:

[0019] The synthesis gas S1 can be synthesis gas of various specifications in the art. For example, the synthesis gas S1 is a gas component containing hydrogen and carbon monoxide. Preferably, the molar ratio of hydrogen to carbon monoxide in the synthesis gas S1 is (0.5-5.5):1, preferably (0.5-3):1. In the above step 1), hydrogen is optionally introduced into the first reaction unit according to the gas composition of the synthesis gas introduced during the continuous industrial production process to adjust the ratio of hydrogen to carbon monoxide in the synthesis gas within the above range.

[0020] The molar ratio of vinyl acetate to synthesis gas S1 is 1:(1-21), preferably 1:(1-10), wherein the molar amount of synthesis gas S1 is calculated based on the total molar amount of hydrogen and carbon monoxide therein;

[0021] The catalyst is selected from at least one of compounds containing the metal component cobalt, and can be a cobalt compound and / or complex commonly used in the art; preferably, the catalyst is octacarbonyl cobalt; the amount of the catalyst can be within the commonly used amount range in the art, for example, in terms of molar amount, the amount of the catalyst is 0.3-10 mol%, preferably 0.5-5 mol% of vinyl acetate;

[0022] The solvent is selected from at least one of aromatic hydrocarbon solvents and acyloxyaldehyde compounds, preferably 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 and 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 a crude product of a 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 and solvent can be added to the reaction system in a mixed form, wherein the content of the catalyst can be varied in a wide range, preferably, based on the total amount of the catalyst and the solvent being 100wt%, the catalyst is 1-30wt% of the total amount of the catalyst and the solvent, preferably 10-20wt%;

[0024] The reaction conditions of the first reaction unit are: reaction temperature of 50-150°C, reaction pressure of 0.5-8MPa, and reaction residence time of 30-180min; preferably, the reaction temperature is 80-130°C, the reaction pressure is 1-7MPa, and the reaction residence time is 30-120min.

[0025] According to the present invention, in step 2) of the method for producing acetoxypropionaldehyde:

[0026] The liquid component L1 obtained by the first reaction unit comprises reaction products 2-acetoxypropionaldehyde and 3-acetoxypropionaldehyde, a catalyst, a solvent, and unreacted vinyl acetate, etc., wherein the liquid product L1-1 recycled to the first reaction unit accounts for 8 to 90%, preferably 10 to 50%, of the liquid component L1; preferably, the liquid 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 component L1-2 after cooling is 25 to 90° C., preferably 25 to 80° C.;

[0027] The operating conditions of the first separation unit are not particularly limited, and separation conditions commonly used in the art may be adopted, for example, flash evaporation at a pressure of 0.5 to 2.5 MPa, cooling separation at 45 to 80° C., or a combination thereof.

[0028] According to the present invention, in step 3) of the method for producing acetoxypropionaldehyde:

[0029] In the second separation unit, the oxidizing gas is a gas atmosphere containing oxygen, preferably, the oxygen content in the oxidizing gas is 0.5-25wt%; specifically, it can be air, or a mixed gas of air and oxygen; an excess of oxidizing gas is introduced into the second separation unit to precipitate the catalyst, and the catalyst is separated from the product system; the amount of the oxidizing gas is not particularly limited, as long as the catalyst can be completely precipitated and recovered, for example, the molar ratio of the oxidizing gas S3 to the catalyst is 1-99, preferably 1-90;

[0030] The operation process of the second separation unit is not particularly limited, and a separation method commonly used in the art can be used. Specifically, the liquid phase component L2 enters the second separation unit, and an excess of oxidizing gas is introduced to precipitate the catalyst. The remaining liquid phase material after filtration separation is directly separated or separated by a separation tower to obtain a catalyst, a solvent and a crude product stream, wherein the separation tower equipment can adopt the separation tower equipment and operating conditions commonly used in the art, for example, the pressure is 5 to 201 kPa, the number of plates is 5 to 40, and the reflux ratio is 0.1 to 10;

[0031] The third separation unit can be various separation equipment and combinations known in the art, as long as it can separate the crude acetoxypropionaldehyde product, light components and logistics containing unreacted materials. For example, a separation tower can be used. The operating conditions of the separation tower can be various conditions known in the art. Preferably, the top temperature of the separation tower is 80-120°C, the bottom temperature is 90-150°C, the pressure is 10-200Kpa(g), the number of plates is 5-40, and the reflux ratio is 0.1-10; the obtained crude acetoxypropionaldehyde product includes 2-acetoxypropionaldehyde and 3-acetoxypropionaldehyde, and the light components mainly contain acetic acid and ethyl acetate;

[0032] The catalyst and solvent obtained from the second separation unit are circulated to the first reaction unit and the second reaction unit respectively. The ratio of the catalyst and solvent circulation amount is not particularly limited and can be adjusted within a wide range. Preferably, the catalyst circulated to the first reaction unit is 50-99% of the total amount of the catalyst obtained by the second separation unit, preferably 60-99%; the catalyst circulated to the second reaction unit is 1-50% of the total amount of the catalyst obtained by the second separation unit, preferably 1-40%; the solvent circulated to the first reaction unit is 50-99% of the total amount of the solvent obtained by the second separation unit, preferably 60-99%; the solvent circulated to the second reaction unit is 1-50% of the total amount of the solvent obtained by the second separation unit, preferably 1-40%. The recycled catalyst and solvent can be partially or completely returned to the first reaction unit and the second reaction unit according to actual needs, and the remaining part is discharged for recovery.

[0033] According to the present invention, in step 4) of the method for producing acetoxypropionaldehyde:

[0034] The synthesis gas S2 may be synthesis gas of various specifications in the art. For example, the synthesis gas S2 is a gas component containing hydrogen and carbon monoxide. Preferably, the molar ratio of hydrogen to carbon monoxide in the synthesis gas S2 is (0.5-5.5):1, preferably (0.5-3):1. In the continuous industrial production process, hydrogen is optionally introduced into the second reaction unit according to the gas composition of the synthesis gas, so as to adjust the ratio of hydrogen to carbon monoxide in the synthesis gas within the above range.

[0035] The molar ratio of the synthesis gas S2 to the vinyl acetate in the unreacted stream G4 is (1-21):1, preferably (1-10):1, wherein the molar amount of the synthesis gas S2 is calculated based on the total molar amount of hydrogen and carbon monoxide therein;

[0036] In the second reaction unit, the amount of catalyst used is 0.3 to 20 wt % of the vinyl acetate in the unreacted stream G4, preferably 1 to 18 wt %;

[0037] The reaction conditions of the second reaction unit are: reaction temperature of 50-150°C, reaction pressure of 0.5-8MPa, and reaction residence time of 30-180min; preferably, reaction temperature of 80-130°C, reaction pressure of 1-7MPa, and reaction residence time of 30-120min;

[0038] In the second reaction unit, the obtained gas phase product and liquid phase product are sent to the first separation unit, and the above separation operation is repeated, the catalyst and solvent therein are recovered and recycled, and a crude acetoxypropionaldehyde product is obtained.

[0039] The production method of acetoxypropionaldehyde provided by the present invention is suitable for a continuous production process. During the initial reaction, an appropriate amount of catalyst and solvent are added to the first reaction unit. During the continuous production process, vinyl acetate and synthesis gas are added to the first reaction unit and the second reaction unit in a timely manner. In addition, the circulating ratio of the catalyst and the solvent is regulated during the separation process, so that the amount ratio of vinyl acetate and the catalyst in the first reaction unit and the second reaction unit is within an appropriate range, the reaction residence time is guaranteed, and the reaction efficiency is improved.

[0040] The third object of the present invention is to use the above-mentioned production device of acetoxypropionaldehyde or the above-mentioned production method of acetoxypropionaldehyde in the preparation of acetoxypropionaldehyde.

[0041] Since the liquid phase obtained by the first reaction unit contains unconverted raw materials and a large amount of acetoxypropionaldehyde products, the efficiency of the second reaction unit will be reduced. The present invention sets a separation unit between the first reaction unit and the second reaction unit to separate the crude product, light components, and logistics containing unreacted materials, and then the unreacted materials are sent to the second reaction unit, and the catalyst and solvent obtained in the separation process are returned to the first reaction unit and the second reaction unit in a recycling manner. This method can effectively improve the reaction efficiency of the second reaction unit, reduce the scale of the second reaction unit device, reduce side reactions, reduce energy consumption, and reduce the complexity of the subsequent separation process when the product is used as the solvent, reduce energy consumption, and improve the recovery rate; and the catalyst ratio of the first reaction unit and the second reaction unit is flexibly adjusted to ensure the reaction residence time and reaction efficiency.

[0042] The present invention provides a plurality of reaction units and gas-liquid separation units, rationally arranges the material flow direction, flexibly adjusts the catalyst ratio of each reaction unit, saves energy consumption, effectively improves the reaction efficiency of the reaction unit, reduces the scale of the reaction unit device, and reduces side reactions; at the same time, two reaction units can share a set of separation units, which reduces the number of equipment, reduces the equipment size, and saves investment. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0044] Description of reference numerals:

[0045] 1-first reaction unit, 2-second reaction unit, 3-first separation unit, 4-second separation unit, 5-gas component G1 pipeline, 6-gas component G5 pipeline, 7-synthesis gas S1 pipeline, 8-vinyl acetate pipeline, 9-hydrogen pipeline, 10-synthesis gas S2 pipeline, 11-solvent circulation pipeline, 12-oxidation gas pipeline, 13-liquid component L1-1 circulation pipeline, 14-third separation unit, 15-liquid component L5 pipeline, 16-light component discharge pipeline, 17-crude product discharge pipeline, 18-catalyst circulation pipeline, 19-unreacted logistics G4 pipeline. DETAILED DESCRIPTION

[0046] The present invention is described in detail below in conjunction with specific embodiments and drawings. It is necessary to point out that the following embodiments are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made to the present invention by those skilled in the art based on the content of the present invention still fall within the scope of protection of the present invention.

[0047] The raw materials used in the examples and comparative examples, unless otherwise specified, are disclosed in the prior art, for example, they can be directly purchased or prepared according to the preparation methods disclosed in the prior art.

[0048] The embodiment of the present invention adopts the acetoxy propionaldehyde production device such as Figure 1As shown, it includes a first reaction unit 1 and a second reaction unit 2, and a first separation unit 3, a second separation unit 4, and a third separation unit 14 connected in sequence by pipelines are arranged between the first reaction unit 1 and the second reaction unit 2, wherein the first reaction unit 1 is provided with a circulation branch on the liquid phase L1 outlet pipeline connected to the first separation unit 3 and connected to the liquid phase inlet of the first reaction unit 1, the second reaction unit 2 is provided with a pipeline 15 at the liquid phase outlet connected to the first separation unit 3 and a pipeline 6 at the gas phase outlet connected to the first separation unit 3, and the second separation unit 4 is provided with a solvent circulation pipeline 11 and a catalyst circulation pipeline 18, which are respectively connected to the first reaction unit 1 and the second reaction unit 2. The first reaction unit 1 is also provided with a raw material inlet 8, a synthesis gas S1 inlet 7, a gas phase G1 outlet, a liquid phase L1 outlet, and a hydrogen inlet 9; the first separation unit 3 is also provided with a gas phase G2 outlet and a liquid phase L2 outlet; the second separation unit 4 is also provided with an oxidation gas inlet 12, a gas phase G3 outlet, a catalyst outlet 18, and a solvent outlet 11; the third separation unit 14 is also provided with an unreacted stream G4 outlet, an acetoxypropionaldehyde crude product outlet 17, and a light component outlet 16; the unreacted stream G4 outlet is connected to the material inlet of the second reaction unit 2 by a pipeline 19; the second reaction unit 2 is also provided with a synthesis gas S2 inlet 10, a hydrogen inlet 9, a gas phase G5 outlet, and a liquid phase L5 outlet.

[0049] Example 1

[0050] Vinyl acetate, synthesis gas S1 and catalyst solution (the solvent is 3-acetoxypropionaldehyde, and the amount of cobalt compounds in the solution is 11.96% based on cobalt octacarbonyl) are fed into the first reaction unit 1, wherein the introduction rate of vinyl acetate is 2829 kg / h, the introduction rates of the catalyst solution and the solvent are 636.69 kg / h and 86.53 kg / h respectively, the introduction rate of synthesis gas S1 is 1028 kg / h (the molar ratio of hydrogen to carbon monoxide in the synthesis gas is 1.02:1), and the feed molar ratio of synthesis gas S1 to vinyl acetate in the reactor is maintained at about 2.13:1; after the reaction, the gas phase G1 is fed into the first separation unit 3, a part of the liquid phase L1-1 at the bottom of the reactor is cooled to 45°C and then returned to the first reaction unit 1, and the other part L1-2 is fed into the second reaction unit 2, and the ratio of the liquid phase L1-1 returned to the first reaction unit 1 to the total liquid phase L1 produced from the bottom of the first reaction unit is 0.1.

[0051] In the first separation unit 3, the components including the liquid phase components L1-2, the gas phase G1 and the gas phase G5 are depressurized to 1.0 MPa and then flash separated. The obtained gas phase G2 is discharged, and the obtained liquid phase component L2 is sent to the second separation unit 4. 100 kg / h of air is introduced into the second separation unit 4, and the catalyst and the liquid phase are separated by centrifugation. The catalyst is circulated back to the first reaction unit and the second reaction unit at 86.53 kg / h and 14.09 kg / h, respectively. The liquid phase is separated by a distillation tower to obtain 740.33 kg of bottom material as a solvent, which is circulated back to the first reaction unit 636.69 kg / h and the second reaction unit 103.65 kg / h. The second separation unit 4 (distillation tower): the top temperature is 97.7 ° C, the bottom temperature is 123.4 ° C, the pressure is 30 kPa, the number of plates is 23, and the top reflux ratio is 1, so that the other gas phase G3 enters the third separation unit 14.

[0052] The third separation unit 14 is composed of two separation towers, wherein the top temperature of separation tower one is 53.6°C, the bottom temperature is 103.8°C, the pressure is 30kPa, the number of plates is 18, and the unreacted reactants are refluxed at the top of the tower, and the reflux ratio is 8, so that the unreacted vinyl acetate and the like are extracted from the top of the tower and sent to separation tower two. The top temperature of separation tower two is 53.6°C, the bottom temperature is 60°C, the pressure is 50kPa, the number of plates is 22, the top reflux ratio is 5, 218.5kg / h of unreacted flow is extracted from the top of the tower, and 240kg / h of light components mainly containing acetic acid and ethyl acetate are extracted from the bottom of the tower.

[0053] Another stream of synthesis gas S2 (the molar ratio of hydrogen to carbon monoxide in the synthesis gas is 1.26:1) and the unreacted stream G4 produced by the third separation unit 14 are fed into the second reaction unit 2, wherein the introduction rate of the unreacted stream G4 is 218.5 kg / h, and the introduction rate of the synthesis gas S2 is 131 kg / h, and the feed molar ratio of the synthesis gas S2 and the vinyl acetate in the unreacted stream G4 of the second reaction unit 2 is maintained at 4.85:1; the liquid phase G5467.24 kg / h of the product of the second reaction unit 2 is fed into the first separation unit 3 for combined treatment.

[0054] The reaction temperature in the first reaction unit 1 is 109°C and the pressure is 6.5 MPa, and the reaction temperature in the second reaction unit 2 is 115°C and the pressure is 6.0 MPa. The residence time in the first reaction unit is 60 min, and the residence time in the second reaction unit is 80 min. The conversion rate of vinyl acetate is 99%, and the yield is 87.8%.

[0055] Example 2

[0056] The process of Example 1 was followed, except that:

[0057] Vinyl acetate, synthesis gas S1 and catalyst solution (the solvent is 3-acetoxypropionaldehyde, and the amount of cobalt compounds in the solution is 11.21% based on cobalt octacarbonyl) are fed into the first reaction unit 1, wherein the introduction rate of vinyl acetate is 3100 kg / h, the introduction rates of the catalyst and the solvent are 610.83 kg / h and 77.13 kg / h respectively, and the feed molar ratio of synthesis gas S1 to vinyl acetate in the reactor is maintained at about 1.92:1; a part of the bottom liquid phase L1-1 in the first reaction unit 1 is cooled to 45°C and then returned to the first reaction unit 1, and the other part L1-2 is fed to the second reaction unit 2, and the ratio of the liquid phase L1-1 returned to the first reaction unit 1 to the total extracted liquid phase L1 from the bottom of the first reaction unit 1 is 0.2.

[0058] The liquid phase component L2 obtained from the first separation unit 3 is sent to the second separation unit 4, into which 200 kg / h of air is introduced, and the catalyst and the liquid phase are separated by centrifugation. The catalyst is circulated back to the first reaction unit 1 and the second reaction unit 2 at 77.13 kg / h and 12.56 kg / h, respectively. The liquid phase is separated by a rectification tower to obtain 710.27 kg of the bottom material of the tower, which is circulated back to the first reaction unit 610.83 kg / h and the second reaction unit 99.44 kg / h as a solvent. The top temperature is 97.2°C, the bottom temperature is 123.4°C, the pressure is 30 kPa, the number of plates is 23, and the top reflux ratio is 1, so that the other liquid phase L3 enters the third separation unit 14.

[0059] The top temperature of the separation tower 1 in the third separation unit 14 is 51.6°C, the bottom temperature is 98.4°C, the pressure is 25kPa, the number of plates is 18, and the unreacted reactants are refluxed at the top of the tower, and the reflux ratio is 10, so that unreacted vinyl acetate and the like are extracted from the top of the tower and sent to the separation tower 2. The top temperature of the separation tower 2 is 54.4°C, the bottom temperature is 61.1°C, the pressure is 50kPa, the number of plates is 23, the top reflux ratio is 5, the unreacted stream is 252.54kg / h, and the light components mainly containing acetic acid and ethyl acetate are extracted from the bottom of the tower at 240kg / h.

[0060] Another stream of synthesis gas S2 (the molar ratio of hydrogen to carbon monoxide in the synthesis gas is 1.28:1) and the unreacted stream G4 produced by the third separation unit 14 are fed into the second reaction unit 2, wherein the introduction rate of the unreacted stream G4 is 364.54 kg / h, and the introduction rate of the synthesis gas S2 is 131 kg / h, and the feed molar ratio of the synthesis gas S2 and the vinyl acetate in the unreacted stream G4 of the second reaction unit 2 is maintained at 4.45:1; the liquid phase G5495.54 kg / h of the product of the second reaction unit 2 is fed into the first separation unit 3 for combined treatment.

[0061] The reaction temperature in the first reaction unit 1 is 105°C and the pressure is 5.5 MPa, and the reaction temperature in the second reaction unit 2 is 109°C and the pressure is 6.5 MPa. The conversion rate of vinyl acetate is 99% and the yield is 88.6%.

[0062] Example 3

[0063] The process of Example 1 was followed, except that:

[0064] Vinyl acetate, synthesis gas S1 and catalyst solution (the solvent is 3-acetoxypropionaldehyde, and the amount of cobalt compounds in the solution is 15.51% based on cobalt octacarbonyl) are fed into the first reaction unit 1, wherein the introduction rate of vinyl acetate is 3100 kg / h, the introduction rates of the catalyst and the solvent are 581.27 kg / h and 106.69 kg / h respectively, and the feed molar ratio of synthesis gas S1 to vinyl acetate in the reactor is maintained at about 1.91:1; a part of the bottom liquid phase L1-1 in the first reaction unit 1 is cooled to 45°C and then returned to the first reaction unit 1, and the other part L1-2 is fed to the second reaction unit 2, and the ratio of the liquid phase L1-1 returned to the first reaction unit 1 to the total extracted liquid phase L1 from the bottom of the first reaction unit 1 is 0.5.

[0065] The liquid phase component L2 obtained from the first separation unit 3 is sent to the second separation unit 4, into which 250 kg / h of air is introduced, and the catalyst and the liquid phase are separated by centrifugation. The catalyst is circulated back to the first reaction unit 1 and the second reaction unit 2 at 106.69 kg / h and 17.37 kg / h, respectively. The liquid phase is separated by a rectification tower to obtain 675.9 kg of bottom material as a solvent, which is circulated back to the first reaction unit 581.27 kg / h and the second reaction unit 94.63 kg / h, respectively. The top temperature is 98.1°C, the bottom temperature is 123.4°C, the pressure is 30 kPa, the number of plates is 23, and the top reflux ratio is 1, so that the other liquid phase L3 enters the third separation unit 14.

[0066] The top temperature of the separation tower 1 in the third separation unit 14 is 55°C, the bottom temperature is 98.4°C, the pressure is 30kPa, the number of plates is 18, and the unreacted reactants are refluxed at the top of the tower, and the reflux ratio is 10, so that the unreacted vinyl acetate and the like are extracted from the top of the tower and sent to the separation tower 2. The top temperature of the separation tower 2 is 54.4°C, the bottom temperature is 61°C, the pressure is 50kPa, the number of plates is 23, the top reflux ratio is 7, the unreacted flow is 145.89kg / h, and the light components mainly containing acetic acid and ethyl acetate are extracted from the bottom of the tower at 240kg / h.

[0067] Another stream of synthesis gas S2 (the molar ratio of hydrogen to carbon monoxide in the synthesis gas is 1.28:1) and the unreacted stream G4 produced by the third separation unit 14 are fed into the second reaction unit 2, wherein the introduction rate of the unreacted stream G4 is 145.89 kg / h, and the introduction rate of the synthesis gas S2 is 131 kg / h, and the feed molar ratio of the synthesis gas S2 and the vinyl acetate in the unreacted stream G4 of the second reaction unit 2 is maintained at 8.1:1; the liquid phase G5388.89 kg / h of the product of the second reaction unit 2 is fed into the first separation unit 3 for combined treatment.

[0068] The reaction temperature in the first reaction unit 1 is 101°C and the pressure is 6.0 MPa, and the reaction temperature in the second reaction unit 2 is 107°C and the pressure is 6.5 MPa. The conversion rate of vinyl acetate is 99% and the yield is 88.6%.

[0069] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A production device for acetoxypropionaldehyde, comprising a first reaction unit and a second reaction unit, wherein a first separation unit, a second separation unit, and a third separation unit are sequentially connected by pipelines between the first reaction unit and the second reaction unit, wherein: The first reaction unit is provided with a circulation branch on the liquid phase outlet pipeline connected to the first separation unit and connected to the liquid phase inlet of the first reaction unit; the second reaction unit is provided with a pipeline at the liquid phase outlet and connected to the first separation unit; the liquid phase outlet of the second separation unit is provided with pipelines connected to the first reaction unit and the second reaction unit respectively.

2. The production device according to claim 1, characterized in that: The first reaction unit is further provided with a raw material inlet, a synthesis gas inlet, a gas phase outlet, a liquid phase outlet, and an optional hydrogen inlet; preferably, in the first reaction unit, the gas phase outlet is connected to the material inlet of the first separation unit by a pipeline; and / or, The first reaction unit is further provided with a cooling system, preferably a cooling coil; and / or, The first 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 second separation unit by a pipeline; and / or, The second separation unit is further provided with an oxidation gas inlet; and / or, The second separation unit is further provided with a gas phase outlet, a catalyst outlet, and a solvent outlet; preferably, in the second separation unit, the gas phase outlet is connected to the material inlet of the third separation unit by a pipeline; and / or, the catalyst outlet is connected to the first reaction unit and the second reaction unit by a pipeline; and / or, the solvent outlet is connected to the first reaction unit and the second reaction unit by a pipeline; and / or, The third separation unit is further provided with an unreacted stream outlet, an acetoxypropionaldehyde crude product outlet, and a light component outlet; preferably, in the third separation unit, the unreacted stream outlet is connected to the material inlet of the second reaction unit by a pipeline; and / or, The second reaction unit is further provided with a synthesis gas inlet, an optional hydrogen inlet, a gas phase outlet, and a liquid phase outlet; preferably, in the second reaction unit, the gas phase outlet and the liquid phase outlet are respectively connected to the first separation unit by pipelines; and / or, The second reaction unit is provided with a cooling system, preferably a jacketed cooling system.

3. A method for producing acetoxypropionaldehyde, which is implemented on the acetoxypropionaldehyde production device according to claim 1 or 2.

4. The production method according to claim 3, characterized in that: The production method comprises: reacting raw materials, synthesis gas, catalyst and solvent in a first reaction unit, dividing the obtained liquid phase component into two parts, one part is recycled back to the first reaction unit, and the other part is sequentially sent to a first separation unit, a second separation unit and a third separation unit for separation treatment, the unreacted flow obtained after separation is sent to a second reaction unit for further reaction, and the gas phase component and liquid component obtained by the reaction are respectively sent to the first separation unit.

5. The production method according to claim 4, characterized in that: The production method specifically comprises the following steps: 1) Vinyl acetate, catalyst, synthesis gas S1, and solvent are fed into a first reaction unit for contact reaction, and the gas phase G1 obtained after the reaction is fed into a first separation unit; 2) The liquid component L1 obtained after the reaction in the first reaction unit is divided into two parts, one part of the liquid component L1-1 is recycled to the first reaction unit, and the other part of the liquid component L1-2 is sent to the first separation unit, the separated gas component G2 is discharged, and the liquid component L2 continues to enter the second separation unit; 3) In the second separation unit, the gas phase component G3, the catalyst and the solvent are separated under the action of the oxidizing gas; the gas phase component G3 is then sent to the third separation unit to separate the unreacted stream G4, the light component and the crude acetoxypropionaldehyde product; the catalyst separated by the second separation unit is circulated to the first reaction unit and the second reaction unit, and the solvent separated is circulated to the first reaction unit and the second reaction unit; 4) The unreacted flow G4 and the synthesis gas S2 are sent to the second reaction unit for contact reaction, and the gas phase component G5 and the liquid phase component L5 obtained by the reaction are respectively sent to the first separation unit.

6. The production method according to claim 5, characterized in that In the step 1): The synthesis gas S1 is a gas component containing hydrogen and carbon monoxide. Preferably, the molar ratio of hydrogen to carbon monoxide in the synthesis gas S1 is (0.5-5.5):1; and / or, The molar ratio of vinyl acetate to synthesis gas S1 is 1:(1-21), preferably 1:(1-10); and / or, The catalyst is selected from at least one compound containing the metal component cobalt, preferably octacarbonyl cobalt; and / or, In terms of molar dosage, the amount of the catalyst is 0.3 to 10 mol%, preferably 0.5 to 5 mol%, of vinyl acetate; and / or, The solvent is selected from at least one of aromatic hydrocarbon solvents and acyloxyaldehyde compounds, preferably at least one of toluene, o-dichlorobenzene, and acetoxypropionaldehyde compounds; and / or, Based on the total amount of the catalyst and the solvent being 100 wt %, the catalyst is 1 to 30 wt %, preferably 10 to 20 wt % of the total amount of the catalyst and the solvent; and / or, The reaction conditions of the first reaction unit are: reaction temperature of 50-150° C., reaction pressure of 0.5-8 MPa; preferably, reaction temperature of 80-130° C., reaction pressure of 1-7 MPa.

7. The production method according to claim 5, characterized in that: In the step 2): The liquid product L1-1 recycled to the first reaction unit accounts for 8 to 90% of the liquid component L1, preferably 10 to 50%.

8. The production method according to claim 5, characterized in that: In the step 3): In the second separation unit, the oxidizing gas is a gas atmosphere containing oxygen, and preferably, the oxygen content in the oxidizing gas is 0.5-25wt%; and / or, The catalyst recycled to the first reaction unit is 50-99%, preferably 60-99%, of the total amount of catalyst obtained in the second separation unit; and / or, The catalyst recycled to the second reaction unit is 1 to 50%, preferably 1 to 40%, of the total amount of catalyst obtained in the second separation unit; and / or, The solvent recycled to the first reaction unit is 50-99%, preferably 60-99%, of the total amount of solvent obtained in the second separation unit; and / or, The solvent recycled to the second reaction unit is 1 to 50%, preferably 1 to 40%, of the total amount of the solvent obtained in the second separation unit.

9. The production method according to claim 5, characterized in that: In the step 4): The synthesis gas S2 is a gas component containing hydrogen and carbon monoxide. Preferably, the molar ratio of hydrogen to carbon monoxide in the synthesis gas S2 is (0.5-5.5):1; and / or, The molar ratio of the synthesis gas S2 to the vinyl acetate in the unreacted stream G4 is (1-21):1, preferably (1-10):1; and / or, In the second reaction unit, the amount of catalyst used is 0.3 to 20 wt %, preferably 1 to 18 wt % of the vinyl acetate in the unreacted stream G4; and / or, The reaction conditions of the second reaction unit are: reaction temperature of 50-150° C., reaction pressure of 0.5-8 MPa; preferably, reaction temperature of 80-130° C., reaction pressure of 1-7 MPa.

10. Use of a production device for acetoxypropionaldehyde according to claim 1 or 2 or a production method for acetoxypropionaldehyde according to any one of claims 3 to 9 in the preparation of acetoxypropionaldehyde.

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