Copolymerization of isobutene and butene-1

Abstract

The application provides a co-production device and process of isobutyraldehyde and n-butyraldehyde, and particularly relates to the technical field of olefin hydroformylation industry. The co-production device comprises a purification device, a hydroformylation device, a falling film evaporator device, a rectifying tower A, a rectifying tower B and a rectifying tower C which are sequentially connected; the bottom of the rectifying tower A is connected with the rectifying tower B; the bottom of the rectifying tower B is connected with the rectifying tower C. The co-production device realizes the production and separation of isobutyraldehyde and n-butyraldehyde simultaneously in one set of co-production device, effectively reduces energy consumption, is simple in equipment, high in production capacity and suitable for large-scale industrial production. Meanwhile, the obtained n-butyraldehyde and isobutyraldehyde products have a purity of more than 99.8 mol%, and a water content of less than 0.1 mol%, are higher in purity and meet the demand of high-end n-butyraldehyde and isobutyraldehyde products on the market.

Description

Technical Field

[0001] This invention relates to the field of olefin hydroformylation industrial production technology, and in particular to a co-production apparatus and process for isobutyraldehyde and n-butyraldehyde. Background Technology

[0002] Isobutyraldehyde, also known as 2-methylpropionaldehyde, is an organic compound with the chemical formula C4H8O. It is a colorless, transparent liquid, slightly soluble in water, and miscible with ethanol, ether, etc. From isobutyraldehyde, a variety of high-value-added chemical products can be derived, such as isobutanol, neopentyl glycol, methacrylic acid, and methyl ethyl ketone.

[0003] n-Butyraldehyde has similar properties to isobutyraldehyde and is its isomer. It is an important intermediate. After condensation and dehydration, hydrogenation yields 2-ethylhexanol, an important plasticizer raw material, as well as a significant solvent in rubber and pharmaceutical products. Furthermore, it is used as an intermediate in resins, vulcanization accelerators, and pesticides.

[0004] Currently, industrial plants using the low-pressure hydroformylation of propylene primarily aim to produce butanol and octanol. n- and isobutyraldehyde are only intermediate products, and the ratio of n- to isobutyraldehyde produced is often above 10:1, resulting in a significantly lower concentration of isobutyraldehyde in the mixed butyraldehyde product compared to n-butyraldehyde. This means that only a portion of the n-butyraldehyde in the hydroformylation product mixture is crudely separated as a feedstock for subsequent octanol production. The remaining n- and isobutyraldehyde are hydrogenated to produce a mixture of n- and isobutanol, which is then purified using a distillation system. This method is insufficient to meet the current strong market demand for higher-purity isobutyraldehyde products.

[0005] In view of this, the present invention is hereby proposed. Summary of the Invention

[0006] One of the objectives of this invention is to provide a co-production device for isobutyraldehyde and n-butyraldehyde, so as to alleviate the technical problem that there is no co-production device for isobutyraldehyde and n-butyraldehyde in the prior art.

[0007] The second objective of this invention is to provide a co-production process for isobutyraldehyde and n-butyraldehyde to alleviate the technical problem of low purity of isobutyraldehyde and n-butyraldehyde in the prior art.

[0008] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted:

[0009] The first aspect of the present invention provides a co-production apparatus for isobutyraldehyde and n-butyraldehyde, comprising a purification device, a hydroformylation device, a falling film evaporator device, a distillation column A, a distillation column B and a distillation column C connected in sequence.

[0010] The bottom of distillation column A is connected to distillation column B;

[0011] The bottom of distillation column B is connected to distillation column C.

[0012] Furthermore, the distillation column A has 7 to 10 theoretical plates, preferably 8.

[0013] Furthermore, the theoretical number of plates in the distillation column B is 60-100, preferably 70-80;

[0014] Preferably, the top of the distillation column B is provided with a reflux tank, which is an oil-water separation reflux tank.

[0015] Furthermore, the distillation column B is a valve-fed column with an actual number of 130-160 plates, and the side stream is drawn from the 4th to the 20th plate from the top of the column.

[0016] Preferably, the distillation column B is a valved column with an actual number of 140-155 plates, and the side stream is drawn from the 4th to 15th plates from the top of the column.

[0017] Furthermore, the theoretical number of plates in the distillation column C is 5 to 20, preferably 10 to 15.

[0018] Furthermore, the falling film evaporator device includes a single falling film evaporator, a circulating fan, and a heat exchange device;

[0019] Preferably, the hydroformylation apparatus comprises two hydroformylation reactors connected in series.

[0020] The second aspect of the present invention provides a co-production process for isobutyraldehyde and n-butyraldehyde, which mainly uses the co-production device for isobutyraldehyde and n-butyraldehyde described in the first aspect; wherein, propylene and synthesis gas are purified in a purification device to remove impurities.

[0021] The purified propylene and syngas undergo a hydroformylation reaction in a hydroformylation unit to obtain a mixture.

[0022] The mixture is then introduced into a falling film evaporator for initial separation from the catalyst solution;

[0023] After preliminary separation, the mixture enters distillation column A to remove light components. The bottom product of distillation column A is a mixture of butyraldehyde, which enters distillation column B for distillation separation. The side stream at the top of the column is used to obtain isobutyraldehyde product, and the crude n-butyraldehyde product obtained at the bottom of the column enters distillation column C for distillation separation to obtain n-butyraldehyde product.

[0024] Furthermore, the synthesis gas is a mixture of H2 and CO in a molar ratio of 1-1.05.

[0025] Preferably, the molar ratio of propylene to syngas is 1:2-2.2, more preferably 1:2.05-2.1.

[0026] Furthermore, the pressure of the hydroformylation reaction is 1.2 MPa-1.8 MPa, preferably 1.3 MPa-1.5 MPa.

[0027] Preferably, in the mixture, the molar ratio of n-butyraldehyde to isobutyraldehyde is 3-2:2-1;

[0028] Preferably, the initial separation pressure is 0.1 MPa-0.3 MPa, and more preferably 0.20 MPa-0.26 MPa.

[0029] Preferably, the initial separation temperature is 65℃-105℃, and more preferably 85℃-98℃.

[0030] Furthermore, the operating pressure at the top of the distillation column A is 4 bar to 6 bar, preferably 4 bar to 5.5 bar;

[0031] Preferably, the operating pressure at the top of the distillation column B is 1 bar to 2 bar, and more preferably 1.5 bar;

[0032] Preferably, the reflux ratio of the distillation column B is 10-15, more preferably 12-14;

[0033] Preferably, the operating pressure at the top of the distillation column C is 1 bar to 2 bar, and more preferably 1.5 bar;

[0034] Preferably, the reflux ratio of the distillation column C is 0.2-1, more preferably 0.2-0.4.

[0035] Furthermore, in the oil-water separation reflux tank of the distillation column B, the operating temperature is 40℃-50℃, preferably 41℃-45℃; the recovery residence time is 15min-45min, preferably 20min-40min.

[0036] Compared with the prior art, the present invention has at least the following beneficial effects:

[0037] The co-production device for isobutyraldehyde and n-butyraldehyde provided by this invention uses a purification device, a hydroformylation device, a falling film evaporator device, a distillation column A, a distillation column B, and a distillation column C connected in sequence. In one co-production device, the production and separation of isobutyraldehyde and n-butyraldehyde are realized simultaneously, which effectively reduces energy consumption, has simple equipment, high capacity, and is suitable for large-scale industrial production.

[0038] The co-production process of isobutyraldehyde and n-butyraldehyde provided by this invention yields n- and isobutyraldehyde products with a purity of over 99.8 mol% and a water content of less than 0.1 mol%, achieving higher purity and meeting the market demand for high-end n- and isobutyraldehyde products. Attached Figure Description

[0039] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0040] Figure 1 A diagram of the co-production apparatus for isobutyraldehyde and n-butyraldehyde provided by the present invention;

[0041] Figure 2 A process route diagram for the co-production of isobutyraldehyde and n-butyraldehyde provided by the present invention.

[0042] Icons: 100 - Purification unit; 200 - Hydroformylation unit; 201 - Fluid transport equipment; 300 - Falling film evaporator unit; 400 - Distillation column A; 401 - Reboiler; 500 - Distillation column B; 600 - Distillation column C; 601 - Condenser. Detailed Implementation

[0043] The embodiments and examples of the present invention will be described in detail below with reference to the implementation methods and examples. However, those skilled in the art will understand that the following implementation methods and examples are only for illustrating the present invention and should not be regarded as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0044] The first aspect of the present invention provides a co-production apparatus for isobutyraldehyde and n-butyraldehyde, comprising a purification device, a hydroformylation device, a falling film evaporator device, a distillation column A, a distillation column B and a distillation column C connected in sequence.

[0045] The bottom of distillation column A is connected to distillation column B;

[0046] The bottom of distillation column B is connected to distillation column C.

[0047] The co-production apparatus for isobutyraldehyde and n-butyraldehyde provided by this invention, such as... Figure 1 As shown, using a purification unit, a hydroformylation unit, a falling film evaporator unit, a distillation column A, a distillation column B, and a distillation column C connected in sequence, the production and separation of isobutyraldehyde and n-butyraldehyde are simultaneously achieved in a single co-production unit. This effectively reduces energy consumption, and the equipment is simple, has high capacity, and is suitable for large-scale industrial production.

[0048] The co-production unit of isobutyraldehyde and n-butyraldehyde includes a purification unit 100, a hydroformylation unit 200, a falling film evaporator unit 300, a distillation column A400, a distillation column B500 and a distillation column C600 connected in sequence.

[0049] The bottom of distillation column A400 is connected to distillation column B500; the theoretical number of plates in distillation column A400 is 7-10, preferably 8.

[0050] The bottom of distillation column B500 is connected to distillation column C600; the theoretical number of plates in distillation column B500 is 60-100, preferably 70-80; the theoretical number of plates in distillation column C600 is 5-20, preferably 10-15.

[0051] Each of the distillation columns A400, B500, and C600 has an independent reboiler 401 at its bottom and an independent condenser 601 at its top.

[0052] In some embodiments of the present invention, a fluid transport device 201 is provided between the hydroformylation unit 200 and the falling film evaporator unit 300 for transporting material from the falling film evaporator unit 300 to the hydroformylation unit 200. The fluid transport device 201 is typically, but not limited to, a centrifugal pump, a reciprocating pump, and a rotary pump.

[0053] In some embodiments of the present invention, a reflux tank is provided at the top of the distillation column B500, and the reflux tank is an oil-water separation reflux tank.

[0054] In some embodiments of the present invention, the distillation column B is a floating valve column with an actual number of 130-160 plates, and the side stream is drawn from the 4th to the 20th plate counting from the top of the column.

[0055] In some preferred embodiments of the present invention, the distillation column B is a floating valve column with an actual number of 140-155 plates, and the side stream is drawn from the 4th to the 15th plate counting from the top of the column.

[0056] In some embodiments of the present invention, the falling film evaporator device 300 includes a single falling film evaporator, a circulating fan, and a heat exchange device.

[0057] In some embodiments of the invention, the hydroformylation apparatus 200 includes two hydroformylation reactors connected in series.

[0058] The second aspect of the present invention provides a co-production process for isobutyraldehyde and n-butyraldehyde, which mainly uses the co-production device for isobutyraldehyde and n-butyraldehyde described in the first aspect; wherein, propylene and synthesis gas are purified in a purification device to remove impurities.

[0059] The purified propylene and syngas undergo a hydroformylation reaction in a hydroformylation unit to obtain a mixture.

[0060] The mixture is then introduced into a falling film evaporator for initial separation from the catalyst solution;

[0061] After preliminary separation, the mixture enters distillation column A to remove light components. The bottom product of distillation column A is a mixture of butyraldehyde, which enters distillation column B for distillation separation. The side stream at the top of the column is used to obtain isobutyraldehyde product, and the crude n-butyraldehyde product obtained at the bottom of the column enters distillation column C for distillation separation to obtain n-butyraldehyde product.

[0062] The co-production process of isobutyraldehyde and n-butyraldehyde provided by this invention yields n- and isobutyraldehyde products with a purity of over 99.8 mol% and a water content of less than 0.1 mol%, achieving higher purity and meeting the market demand for high-end n- and isobutyraldehyde products.

[0063] The co-production process of isobutyraldehyde and n-butyraldehyde, such as Figure 2 As shown, the co-production of isobutyraldehyde and n-butyraldehyde is mainly carried out using the co-production device of isobutyraldehyde and n-butyraldehyde described in the first aspect.

[0064] In this process, propylene and syngas are purified in a purification unit to remove impurities;

[0065] The purified propylene and syngas undergo a hydroformylation reaction in a hydroformylation unit to obtain a mixture. During the hydroformylation reaction, a low-to-isobutyraldehyde mixture with a positive-to-negative ratio of 3:2 to 2:1 is produced under a specific catalyst, along with small amounts of byproducts such as tributyraldehyde, butanol, and propane.

[0066] The mixture is then introduced into a falling film evaporator for concentration. After preheating, the mixture, along with circulating non-condensable gas from a circulating fan, enters the tubes evenly from the top of the evaporator via a liquid distribution device. Under gravity, it flows down the inner wall of the tubes in a film form and is evaporated and concentrated. The gas-liquid mixture flows down in parallel and enters the separation chamber from the bottom of the heating tubes. The circulating non-condensable gas reduces the partial pressure of butyraldehyde in the falling film evaporator, thereby lowering the evaporation temperature. The catalyst solution and the crude butyraldehyde mixture are separated. The catalyst solution is returned to the hydroformylation unit for reuse via a fluid conveying device, allowing the catalytic reaction to proceed.

[0067] This application does not limit the catalyst; any catalyst capable of performing the hydroformylation reaction is acceptable. In a typical embodiment of the present invention, the catalyst consists of 0.01 mmol of [Rh(acac)(CO)2], 0.04 mmol of a carbazole-containing phosphorous amide ligand, 0.01 mmol of monobutyl phosphite, and 25 mL of anhydrous toluene, forming a rhodium / phosphite catalytic system as the catalyst.

[0068] The concentrated mixture enters distillation column A to remove light components. The bottom product of distillation column A is a butyraldehyde mixture, which enters distillation column B for distillation separation. The top product is isobutyraldehyde, and the bottom product is crude n-butyraldehyde, which enters distillation column C for distillation separation to obtain n-butyraldehyde.

[0069] Further, the synthesis gas is a mixture of H2 and CO in a molar ratio of 1-1.05. In some embodiments of the invention, the volume ratio of H2 to CO is typically, but not limited to, 1, 1.01, 1.02, 1.03, 1.04, or 1.05.

[0070] Preferably, the molar ratio of propylene to syngas is 1:2-2.2, more preferably 1:2.05-2.1. In some embodiments of the present invention, the volume ratio of propylene to syngas is typically, but not limited to, 1, 1.01, 1.02, 1.03, 1.04, or 1.05.

[0071] Further, the pressure of the hydroformylation reaction is 1.2 MPa-1.8 MPa, preferably 1.3 MPa-1.5 MPa. In some embodiments of the present invention, the pressure of the hydroformylation reaction is typically, but not limited to, 1.2 MPa, 1.3 MPa, 1.4 MPa, 1.5 MPa, 1.6 MPa, 1.7 MPa or 1.8 MPa.

[0072] Preferably, the molar ratio of n-butyraldehyde to isobutyraldehyde in the mixture is 3-2:2-1; in some embodiments of the present invention, the molar ratio of n-butyraldehyde to isobutyraldehyde obtained by the reaction is typically, but not limited to, 3:2, 2:1, 2:2 or 2:1.

[0073] Preferably, the initial separation pressure is 0.1 MPa-0.3 MPa, more preferably 0.20 MPa-0.26 MPa. In some embodiments of the present invention, the initial separation pressure is typically, but not limited to, 0.20 MPa, 0.21 MPa, 0.22 MPa, 0.24 MPa, or 0.26 MPa.

[0074] Preferably, the initial separation temperature is 65℃-105℃, more preferably 85℃-98℃. In some embodiments of the present invention, the initial separation temperature is typically, but not limited to, 65℃, 75℃, 85℃, 90℃, 95℃, or 105℃.

[0075] Furthermore, the operating pressure at the top of the distillation column A is 4 bar to 6 bar, preferably 4 bar to 5.5 bar; in some embodiments of the present invention, the operating pressure at the top of the distillation column A is typically, but not limited to, 4 bar, 4.5 bar, 5 bar, 5.5 bar or 6 bar.

[0076] Preferably, the top operating pressure of the distillation column B is 1 bar to 2 bar, more preferably 1.5 bar; in some embodiments of the present invention, the top operating pressure of the distillation column B is typically, but not limited to, 1 bar, 1.2 bar, 1.5 bar, 1.8 bar or 2 bar.

[0077] Preferably, the reflux ratio of the distillation column B is 10-15, more preferably 12-14; in some embodiments of the present invention, the reflux ratio of the distillation column B is typically, but not limited to, 10, 11, 12, 13, 14 or 15.

[0078] Preferably, the operating pressure at the top of the distillation column C is 1 bar to 2 bar, more preferably 1.5 bar; in some embodiments of the present invention, the operating pressure at the top of the distillation column C is typically, but not limited to, 1 bar, 1.2 bar, 1.5 bar, 1.8 bar or 2 bar.

[0079] Preferably, the reflux ratio of the distillation column C is 0.2-1, more preferably 0.2-0.4. In some embodiments of the present invention, the reflux ratio of the distillation column B is typically, but not limited to, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 or 1.

[0080] Furthermore, in the oil-water separation reflux tank of the distillation column B, the operating temperature is 40℃-50℃, preferably 41℃-45℃; the recovery residence time is 15min-45min, preferably 20min-40min. In some embodiments of the present invention, the operating temperature in the oil-water separation reflux tank of the distillation column B is typically, but not limited to, 40℃, 42℃, 44℃, 46℃, 48℃, or 50℃; the recovery residence time is typically, but not limited to, 15min, 20min, 25min, 30min, 35min, 40min, or 45min.

[0081] The present invention is further illustrated below with specific embodiments and comparative examples. However, it should be understood that these embodiments are merely for illustrative purposes and should not be construed as limiting the invention in any way. Unless otherwise specified, the raw materials used in the embodiments and comparative examples of the present invention were carried out under conventional conditions or conditions recommended by the manufacturer. Reagents or instruments used, unless otherwise specified, are all commercially available conventional products.

[0082] Example 1

[0083] This embodiment provides a process for the co-production of isobutyraldehyde and n-butyraldehyde, such as... Figure 2 As shown, it includes the following steps:

[0084] 1. The raw materials are supplied to the unit at a flow rate of 10 kmol / h for propylene and 20.1 kmol / h for synthesis gas (with a volume ratio of H2 to CO of 1.03). The three raw materials first enter the purification unit, where propylene and synthesis gas are desulfurized to remove any trace amounts of sulfur and chlorine compounds that may be present.

[0085] 2. The purified raw materials and the recycled catalyst-containing liquid stream were sequentially introduced into a hydroformylation reaction system consisting of two reactors connected in series. The catalyst was a rhodium / phosphorous amide catalytic system obtained by mixing [Rh(acac)(CO)2]: a carbazole-containing phosphorous amide ligand: monobutyl phosphite in a molar ratio of 1:4:1. The reaction pressures were 1.5 MPa and 1.3 MPa, respectively, yielding a liquid stream of 12.2 kmol / h, of which n-butyraldehyde accounted for 54.0% and isobutyraldehyde accounted for 35.1% (mole fraction, the same below).

[0086] 3. The mixture enters the falling film evaporator system, where it is separated at 0.21 MPa and 87 °C to obtain 9.9 kmol / h of mixed butyraldehyde, of which n-butyraldehyde accounts for 58.2% and isobutyraldehyde accounts for 38.7%; the catalyst stream is 2.2 kmol / h, which is cooled, pressurized, and replenished with a small amount of catalyst before being recycled back to the hydroformylation reaction system.

[0087] 4. After exchanging heat with the bottom product of distillation column A, the mixed butyraldehyde enters distillation column A. The operating pressure at the top of the column is 4.9 bar, and the bottom product stream is 9.7 kmol / h, of which n-butyraldehyde accounts for 59.5% and isobutyraldehyde accounts for 39.5%. The top product is non-condensable gas cooled by the top condenser.

[0088] 5. The bottom product of distillation column A, after heat exchange with the feed, continues into the subsequent distillation column B. The operating pressure at the top of column B is 1.5 bar. After cooling in the top condenser, the temperature is 45°C. The condensed liquid phase enters the reflux tank for phase separation. The designed residence time in the reflux tank is 30 minutes. The water tank continuously discharges approximately 0.07 kmol / h of wastewater containing organic matter, of which the water content is approximately 98.5%. The actual number of trays in the entire column is 146. Isobutyraldehyde is collected from the liquid phase on the 12th tray and, after cooling, is used as the isobutyraldehyde product (3.8 kmol / h).

[0089] 6. The product from the bottom of distillation column B, after being pressurized, enters distillation column C. The operating pressure at the top of the column is 1.5 bar. The actual number of trays in the entire column is 20, and the reflux ratio is 0.28. The n-butyraldehyde is collected from the top of the column and, after cooling, is used as the n-butyraldehyde product (5.6 kmol / h).

[0090] The final n-butyraldehyde product had a purity of 99.91 mol%, a water content of 0.02 mol%, a heavy matter content of 0.02 mol%, and an isobutyraldehyde content of 0.05 mol%. The isobutyraldehyde product had a purity of 99.86 mol%, a water content of 0.07 mol%, a heavy matter content that was not detected, and a n-butyraldehyde content of 0.07 mol%.

[0091] Example 2

[0092] This embodiment provides a process for the co-production of isobutyraldehyde and n-butyraldehyde, such as... Figure 2 As shown, it includes the following steps:

[0093] 1. The raw materials are supplied to the unit at a flow rate of 10 kmol / h for propylene and 21 kmol / h for synthesis gas (the volume ratio of H2 to CO is 1.03). The three raw materials first enter the purification unit, where propylene and synthesis gas are desulfurized to remove any trace amounts of sulfur and chlorine compounds that may be present.

[0094] 2. The purified raw materials and the recycled catalyst-containing liquid stream were sequentially introduced into a hydroformylation reaction system consisting of two reactors connected in series. The catalyst was a rhodium / phosphorous amide catalytic system obtained by mixing [Rh(acac)(CO)2]: a carbazole-containing phosphorous amide ligand: monobutyl phosphite in a molar ratio of 1:4:1. The reaction pressures were 1.2 MPa and 1.1 MPa, respectively, yielding a liquid stream of 11.1 kmol / h, of which n-butyraldehyde accounted for 53.9% and isobutyraldehyde accounted for 35.0% (mole fraction, the same below).

[0095] 3. The mixture enters the falling film evaporator system, where it is separated at 0.3 MPa and 105 °C to obtain 9.0 kmol / h of mixed butyraldehyde, of which n-butyraldehyde accounts for 58.0% and isobutyraldehyde accounts for 38.5%; the catalyst stream is 2.1 kmol / h, which is cooled, pressurized, and replenished with a small amount of catalyst before being recycled back to the hydroformylation reaction system.

[0096] 4. After exchanging heat with the bottom product of distillation column A, the mixed butyraldehyde enters distillation column A. The operating pressure at the top of the column is 6 bar. The bottom product stream is 8.7 kmol / h, of which n-butyraldehyde accounts for 59.4% and isobutyraldehyde accounts for 39.5%. The top product is non-condensable gas cooled by the top condenser.

[0097] 5. The bottom product of distillation column A, after heat exchange with the feed, continues into the subsequent distillation column B. The operating pressure at the top of the column is 2 bar. After cooling in the top condenser, the temperature is 45°C. The condensed liquid phase enters the reflux tank for phase separation. The designed residence time in the reflux tank is 30 minutes. The water tank continuously discharges approximately 0.07 kmol / h of wastewater containing organic matter, of which the water content is approximately 96.4%. The actual number of trays in the entire column is 146. Isobutyraldehyde is collected from the liquid phase on the 12th tray and, after cooling, is used as the isobutyraldehyde product (3.4 kmol / h).

[0098] 6. The product from the bottom of distillation column B, after being pressurized, enters distillation column C. The operating pressure at the top of the column is 2 bar. The actual number of plates in the entire column is 20, and the reflux ratio is 0.4. n-Butyraldehyde is collected from the top of the column and, after cooling, is used as the n-butyraldehyde product (5.2 kmol / h).

[0099] The final n-butyraldehyde product had a purity of 99.92 mol%, a water content of 0.02 mol%, a heavy matter content of 0.01 mol%, and an isobutyraldehyde content of 0.05 mol%. The isobutyraldehyde product had a purity of 99.86 mol%, a water content of 0.07 mol%, no heavy matter detected, and a n-butyraldehyde content of 0.07 mol%.

[0100] Example 3

[0101] This embodiment provides a process for the co-production of isobutyraldehyde and n-butyraldehyde, such as... Figure 2 As shown, it includes the following steps:

[0102] 1. The raw materials are supplied to the unit at a flow rate of 10 kmol / h for propylene and 20 kmol / h for synthesis gas (with a volume ratio of H2 to CO of 1.05). The three raw materials first enter the purification unit, where propylene and synthesis gas are desulfurized to remove any trace amounts of sulfur and chlorine compounds that may be present.

[0103] 2. The purified raw materials and the recycled catalyst-containing liquid stream were sequentially introduced into a hydroformylation reaction system consisting of two reactors connected in series. The catalyst was a rhodium / phosphorous amide catalytic system obtained by mixing [Rh(acac)(CO)2]: a carbazole-containing phosphorous amide ligand: monobutyl phosphite in a molar ratio of 1:4:1. The reaction pressures were 1.8 MPa and 1.7 MPa, respectively, yielding a liquid stream of 12.2 kmol / h, of which n-butyraldehyde accounted for 53.9% and isobutyraldehyde accounted for 35.0% (mole fraction, the same below).

[0104] 3. The mixture enters the falling film evaporator system, where it is separated at 0.3 MPa and 105 °C to obtain 9.9 kmol / h of mixed butyraldehyde, of which n-butyraldehyde accounts for 58.1% and isobutyraldehyde accounts for 38.6%; the catalyst stream is 2.3 kmol / h, which is cooled, pressurized, and replenished with a small amount of catalyst before being recycled back to the hydroformylation reaction system.

[0105] 4. After exchanging heat with the bottom product of distillation column A, the mixed butyraldehyde enters distillation column A. The operating pressure at the top of the column is 4 bar. The bottom product stream is 9.5 kmol / h, of which n-butyraldehyde accounts for 59.4% and isobutyraldehyde accounts for 39.4%. The top product is non-condensable gas cooled by the top condenser.

[0106] 5. The bottom product of distillation column A, after heat exchange with the feed, continues into the subsequent distillation column B. The operating pressure at the top of the column is 1 bar. After cooling in the top condenser, the temperature is 45°C. The condensed liquid phase enters the reflux tank for phase separation. The designed residence time in the reflux tank is 30 minutes. The water tank continuously discharges approximately 0.07 kmol / h of wastewater containing organic matter, of which the water content is approximately 96.4%. The actual number of trays in the entire column is 146. Isobutyraldehyde is collected from the liquid phase on the 12th tray and, after cooling, is used as the isobutyraldehyde product (3.7 kmol / h).

[0107] 6. The product from the bottom of distillation column B, after being pressurized, enters distillation column C. The operating pressure at the top of the column is 1 bar. The actual number of plates in the entire column is 20, and the reflux ratio is 0.2. The n-butyraldehyde is collected from the top of the column and, after cooling, is used as the n-butyraldehyde product (5.5 kmol / h).

[0108] The final n-butyraldehyde product had a purity of 99.88 mol%, a water content of 0.03 mol%, a heavy matter content of 0.02 mol%, and an isobutyraldehyde content of 0.07 mol%. The isobutyraldehyde product had a purity of 99.85 mol%, a water content of 0.08 mol%, no heavy matter detected, and a n-butyraldehyde content of 0.07 mol%.

[0109] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A co-production device for isobutyraldehyde and n-butyraldehyde, characterized in that, It includes a purification unit, a hydroformylation unit, a falling film evaporator unit, a distillation column A, a distillation column B, and a distillation column C connected in sequence; The co-production unit is used to process a mixture of n-butyraldehyde and isobutyraldehyde in a molar ratio of 3-2:2-1; The theoretical number of plates in distillation column A is 7-10, the theoretical number of plates in distillation column B is 60-100, and the theoretical number of plates in distillation column C is 5-20. The bottom of distillation column A is connected to distillation column B, and a reflux tank is provided at the top of distillation column B. The reflux tank is an oil-water separation reflux tank. The bottom of distillation column B is connected to distillation column C; The falling film evaporator device includes a single falling film evaporator, a circulating fan, and a heat exchange device.

2. The cogeneration unit according to claim 1, characterized in that, The distillation column A has 8 theoretical plates.

3. The cogeneration unit according to claim 1, characterized in that, The theoretical number of plates in distillation column B is 70-80.

4. The cogeneration unit according to claim 1, characterized in that, The distillation column B is a valved column with an actual number of 130-160 plates. The side stream is drawn from the 4th to the 20th plate from the top of the column.

5. The cogeneration unit according to claim 1, characterized in that, The distillation column B is a valved column with an actual number of 140-155 plates. The side stream is drawn from the 4th to the 15th plate from the top of the column.

6. The cogeneration unit according to claim 1, characterized in that, The theoretical number of plates in the distillation column C is 10-15.

7. The cogeneration unit according to claim 1, characterized in that, The hydroformylation unit comprises two hydroformylation reactors connected in series.

8. A process for the co-production of isobutyraldehyde and n-butyraldehyde, characterized in that, The co-production of isobutyraldehyde and n-butyraldehyde is mainly carried out using the co-production device of isobutyraldehyde and n-butyraldehyde as described in any one of claims 1-7; wherein, propylene and synthesis gas are purified in a purification device to remove impurities. The purified propylene and syngas undergo a hydroformylation reaction in a hydroformylation unit to obtain a mixture. The mixture is then introduced into a falling film evaporator for initial separation from the catalyst solution. After preliminary separation, the mixture enters distillation column A to remove light components. The bottom product of distillation column A is a mixture of butyraldehyde, which enters distillation column B for distillation separation. The side stream at the top of the column is used to obtain isobutyraldehyde product, and the crude n-butyraldehyde product obtained at the bottom of the column enters distillation column C for distillation separation to obtain n-butyraldehyde product.

9. The co-production process according to claim 8, characterized in that, The synthesis gas is a mixture of H2 and CO in a molar ratio of 1-1.

05.

10. The co-production process according to claim 8, characterized in that, The molar ratio of propylene to syngas is 1:2-2.

2.

11. The co-production process according to claim 8, characterized in that, The molar ratio of propylene to syngas is 1:2.05-2.

1.

12. The co-production process according to claim 8, characterized in that, The hydroformylation reaction is carried out at a pressure of 1.2 MPa to 1.8 MPa.

13. The co-production process according to claim 8, characterized in that, The hydroformylation reaction is carried out at a pressure of 1.3 MPa to 1.5 MPa.

14. The co-production process according to claim 8, characterized in that, In the mixture, the molar ratio of n-butyraldehyde to isobutyraldehyde is 3-2:2-1.

15. The co-production process according to claim 8, characterized in that, The initial separation pressure is 0.1 MPa-0.3 MPa.

16. The co-production process according to claim 8, characterized in that, The initial separation pressure is 0.20 MPa - 0.26 MPa.

17. The co-production process according to claim 8, characterized in that, The initial separation temperature is 65℃-105℃.

18. The co-production process according to claim 8, characterized in that, The initial separation temperature is 85℃-98℃.

19. The co-production process according to claim 8, characterized in that, The operating pressure at the top of distillation column A is 4 bar to 6 bar.

20. The co-production process according to claim 8, characterized in that, The operating pressure at the top of distillation column A is 4 bar to 5.5 bar.

21. The co-production process according to claim 8, characterized in that, The operating pressure at the top of distillation column B is 1 bar to 2 bar.

22. The co-production process according to claim 8, characterized in that, The operating pressure at the top of distillation column B is 1.5 bar.

23. The co-production process according to claim 8, characterized in that, The reflux ratio of the distillation column B is 10-15.

24. The co-production process according to claim 8, characterized in that, The reflux ratio of the distillation column B is 12-14.

25. The co-production process according to claim 8, characterized in that, The operating pressure at the top of the distillation column C is 1 bar to 2 bar.

26. The co-production process according to claim 8, characterized in that, The operating pressure at the top of the distillation column C is 1.5 bar.

27. The co-production process according to claim 8, characterized in that, The reflux ratio of the distillation column C is 0.2-1.

28. The co-production process according to claim 8, characterized in that, The reflux ratio of the distillation column C is 0.2-0.4.

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