A method and device for hydroformylation reaction

Abstract

The present invention provides a method and apparatus for hydroformylation reaction, the method comprising the following steps: (A) a cobalt-phosphine complex catalyst solution and an olefin are passed through a hydroformylation reactor for reaction; (B) a crude reaction product is separated; (C) most of the material containing the cobalt-phosphine catalyst is returned to the entrance of the hydroformylation reactor for recycling; a small portion of heavy materials enters a post-processing reactor; (D) the effluent material of the post-processing reactor is subjected to distillation separation, the tower top obtains the product, and the tower bottom residual material is discharged from the reactor. The inventive method carries out post-processing on the externally thrown material containing heavy objects, and the heavy by-products are decomposed into products such as alcohol and aldehyde again, significantly reducing the externally thrown material amount, reducing waste liquid discharge, being beneficial to environmental protection, and having industrialization prospects.

Description

Technical Field

[0001] The present invention relates to the preparation of oxygen-containing compounds, and in particular to a method and device for preparing aldehydes and alcohols through olefin hydroformylation reaction. Background Art

[0002] Olefins undergo hydroformylation with carbon monoxide and hydrogen in the presence of a catalyst. The hydroformylation process involves contacting an olefinically unsaturated compound with carbon monoxide and hydrogen in the presence of a catalyst under reaction conditions to produce one or more aldehydes or alcohols. The catalysts used in industrial hydroformylation reactions are generally cobalt (Co)-based or rhodium (Rh)-based catalysts.

[0003] CN102123978A discloses a method for hydroformylating alpha-olefins to produce two or more aldehydes comprising an n-aldehyde and one or more isomeric aldehydes, wherein the target molar ratio of the n-aldehyde to the one or more isomeric aldehydes is within a selectable range of 3 / 1 to 60 / 1. The method uses a transition metal-ligand complex catalyst comprising a symmetrical calixarene diphosphite ligand.

[0004] CN108586219A discloses a method for preparing aldehydes by hydroformylation of olefins. The preparation method is as follows: step 1: C2-C4 olefins are subjected to a hydroformylation reaction with carbon monoxide and hydrogen in the presence of a catalyst in a first reactor to continuously prepare aldehydes, while the temperature is 90°C and the pressure is 2.5 MPa; step 2: heating the second reactor to 70-80°C while introducing an inert gas into the second reactor; step 3: connecting the first reactor and the second reactor, and introducing the aldehyde prepared in the first reactor into the second reactor; step 4: during the introduction in step 3, the aldehyde is introduced under isobaric and unequal temperature conditions, and a secondary introduction is performed after the introduction. This technology has a complex reaction process and uses a rhodium-phosphine complex catalyst, which is expensive.

[0005] Compared to cobalt catalysts, rhodium complexes are more reactive and can react at milder temperatures and pressures. However, rhodium catalysts have poor high-temperature performance, making their use in higher olefin carbonylation difficult. Existing rhodium catalysts are effective for terminal olefins but less active for internal olefins. The catalysts are oil-soluble, making product separation difficult and complicating post-processing. Rhodium, as a precious metal resource, is scarce and expensive, leading to high recycling costs.

[0006] CN1257140C discloses a continuous process for the hydroformylation of olefins having 6 to 20 carbon atoms, wherein: a) an aqueous solution of a cobalt(II) salt is contacted with hydrogen and carbon monoxide to form a hydroformylation-active cobalt catalyst, and then an aqueous phase containing the cobalt catalyst is contacted with the olefin and, optionally, an organic solvent as well as hydrogen and carbon monoxide in at least one reaction zone, wherein the cobalt catalyst is extracted into the organic phase and the olefin is hydroformylated; b) the effluent from the reaction zone is treated with oxygen in the presence of an acidic aqueous solution of a cobalt(II) salt, wherein the cobalt catalyst decomposes to form cobalt(II) salts and these are stripped into the aqueous phase; and the phases are subsequently separated; c) the aqueous solution of the cobalt(II) salt is recycled to step a in unchanged form. This process is complex.

[0007] The prior art uses a cobalt hydroformylation catalyst, which generally has a high reaction pressure, such as about 25 MPa, and a large fixed investment in the device.

[0008] During the hydroformylation process, as the catalyst is continuously recycled, the heavy material content in the recycled material slowly increases, affecting the normal operation of the device. Therefore, after a certain period of material recycling, some of the heavy catalyst-containing material needs to be discharged from the reactor. This discharged material is treated as waste liquid, which places a great pressure on environmental protection. The amount of discharged material also determines the industrial implementation prospects of the hydroformylation process. Summary of the Invention

[0009] The present invention provides a hydroformylation reaction method, which can significantly reduce the amount of discarded materials, thereby reducing waste liquid discharge and alleviating environmental problems of the hydroformylation process.

[0010] The invention also provides a device for hydroformylation reaction.

[0011] In a first aspect, the present invention provides a method for a hydroformylation reaction, comprising the following steps:

[0012] (A) introducing a cobalt-phosphine complex catalyst solution and an olefin into a hydroformylation reactor to carry out a hydroformylation reaction under a synthesis gas environment;

[0013] (B) separating the crude reaction product to obtain a mixed product of alcohol, aldehyde and alkane from the light component and a material containing a cobalt-phosphine complex catalyst from the heavy component;

[0014] (C) Most of the material containing the cobalt-phosphine catalyst is returned to the inlet of the hydroformylation reactor for recycling; a small portion of the heavy material enters the post-treatment reactor, where water is added and no olefin is introduced, and post-treatment is carried out in a synthesis gas atmosphere;

[0015] (D) The outflow material of the post-treatment reactor is subjected to distillation separation, the target product is obtained at the top of the tower, and the residual material at the bottom of the tower is discharged from the reactor.

[0016] The inventors of this application discovered that as catalyst-containing materials are continuously recycled, the content of heavy materials in the recycled materials slowly increases. Analysis shows that the heavy materials contain a large number of large molecular weight carbonyl-containing byproducts. The inventors of this application proposed that this portion of heavy materials be sent to a post-processing reactor, where water is added, synthesis gas is introduced without olefins, and post-processing is performed under hydroformylation reaction conditions. Unexpectedly, the water causes the large molecular weight heavy byproducts to decompose again into products such as alcohols and aldehydes. This not only further increases the yield of the target product but also significantly reduces the amount of waste material, thereby significantly reducing waste liquid emissions and alleviating environmental issues in the hydroformylation process.

[0017] According to the method of the present invention, before the hydroformylation reaction, the catalyst solution can also be pretreated in a pretreatment reactor, which can be an autoclave or a tubular reactor. The pretreatment is carried out under a synthesis gas atmosphere, the pretreatment reactor temperature is 50°C to 150°C, preferably 75°C to 130°C, more preferably 90°C to 120°C, the pressure is 1MPa to 12MPa, preferably 3MPa to 10MPa, more preferably 5MPa to 8MPa, and the pretreatment time is 0.1-10 hours, preferably 1-3 hours. Catalyst pretreatment is conducive to the formation of active units of the cobalt-phosphine catalyst, reduces catalyst decomposition, improves the activity and stability of the catalyst, and extends the service life of the catalyst.

[0018] If pretreatment is performed, the material containing the cobalt phosphine complex catalyst can be recycled to the inlet of the pretreatment reactor for reuse.

[0019] According to the method of the present invention, when the material containing the cobalt-phosphine complex catalyst is returned to the inlet of the hydroformylation reactor and / or the pretreatment reactor, a small amount of new catalyst can be added as needed.

[0020] According to the method of the present invention, in step (A), the mass concentration of cobalt in the cobalt-phosphine complex catalyst solution is 0.05%-3%, preferably 0.2%-2%, more preferably 0.5%-1.5%, and most preferably 0.6%-1%.

[0021] In the cobalt-phosphine complex catalyst solution, the mass ratio of cobalt-containing raw material to cobalt and phosphorus of phosphine ligand can be 1:(0.1-3), preferably 1:(0.2-2), more preferably 1:(0.3-1).

[0022] The cobalt-containing raw material can be a cobalt salt or a cobalt oxide, wherein the cobalt salt can be an inorganic acid cobalt or an organic acid cobalt, for example, one or more selected from the group consisting of cobalt carbonate, cobalt nitrate, cobalt acetate, cobalt levulinate, cobalt formate, octacarbonyl dicobalt and cobalt naphthenate.

[0023] The phosphine ligand may be various ligands known in the art, such as one or more of phosphite, triphenylphosphine, trialkylphosphine, di-(triphenylphosphine), alkylphenylphosphine, etc., preferably triphenylphosphine or tributylphosphine.

[0024] The cobalt-phosphine complex catalyst solution can be prepared according to a known method, for example, by dissolving a cobalt-containing raw material and a phosphine ligand in a solvent, introducing CO and H2 gases to a pressure of 1-6 MPa, preferably 2-4 MPa, and reacting at 80-180°C, preferably 100-150°C, for 0.5-24 hours, preferably 1-15 hours, more preferably 3-10 hours to obtain a cobalt-phosphine catalyst solution.

[0025] The solvent in the cobalt-phosphine complex catalyst solution can be various solvents known in the art, such as olefins, alkanes, alcohols, etc., preferably various types of C1-C20 alcohols. In addition, the solvent can contain products or raw materials.

[0026] The solvent in the cobalt-phosphine complex catalyst solution is preferably a strongly soluble mixed solvent. The strongly soluble mixed solvent is the solution after the hydroformylation reaction in step (A) is completed, or the solution formed by distilling off part of the product and / or part of the solvent. The concentration of the cobalt-phosphine catalyst in this solution can be significantly increased, thereby reducing the reaction temperature and improving the total yield of the alcohol and aldehyde.

[0027] According to the present method, the olefin in step (A) is a C1-C30 olefin, preferably a C6-C20 olefin. The olefin may be a linear olefin and / or a branched olefin, and the number of branches of the branched olefin may be ≥1. The present invention is particularly suitable for mixtures of C8 olefins containing one or more of 2,4,4-trimethyl-1-pentene and 2,4,4-trimethyl-2-pentene. Due to the large steric hindrance, the hydroformylation of multi-branched trimethyl olefins is more difficult than that of less branched olefins.

[0028] The synthesis gas is a mixture of carbon monoxide and hydrogen, wherein the molar ratio of carbon monoxide to hydrogen is 4:1 to 1:4, preferably 3:1 to 1:3, and more preferably 2:1 to 1:2.

[0029] According to the method of the present invention, the pretreatment reactor, hydroformylation reactor, and post-treatment reactor can be either tubular reactors or kettle reactors. When the hydroformylation reactor is a tubular reactor, the olefins, synthesis gas, and catalyst-containing solution flow into the tubular reactor from the bottom, and the reaction products flow out from the top. Alternatively, the olefins flow into the tubular reactor from the top, and the reaction products flow out from the bottom. After the reaction is completed, a portion of the alcohol, aldehyde, alkane, and olefin raw materials are distilled from the crude reaction product, and the remaining catalyst-containing solution is circulated to the pre-reactor for pretreatment. After pretreatment, the catalyst-containing solution is delivered to the inlet of the hydroformylation reactor and re-enters the reactor for use.

[0030] The hydroformylation reactor temperature is 60°C to 250°C, preferably 100°C to 220°C, more preferably 100°C to 180°C; most preferably 110°C to 140°C. Two or more hydroformylation reactors may be used, preferably in series. The reactor temperatures may be the same or different. The reaction temperature may be equal, lower at the beginning and higher at the end, or higher at the beginning and lower at the end. The residence time of the material in the high-temperature reaction zone should be reduced, which helps reduce the residence time of the catalyst in the higher reaction temperature zone and reduce catalyst decomposition. The reaction pressure may be 1MPa to 12MPa, preferably 2MPa to 10MPa, more preferably 5MPa to 8MPa. The reaction time is 1-40 hours, preferably 3-20 hours, more preferably 5-10 hours.

[0031] Synthesis gas can flow from the lower portion of a pretreatment reactor and / or a hydroformylation reactor, or from the lower portions of multiple hydroformylation reactors. Furthermore, the ratio of CO to H₂ in the synthesis gas flowing into different reactors can be the same or different. This facilitates adjustment of the ratio of olefins to CO and H₂ in each reactor to the optimal value, facilitating higher conversion and better selectivity. The molar ratio of synthesis gas to olefins is (1-12):1, preferably (3-6):1.

[0032] The mass ratio of the catalyst solution to the olefin is (0.1-10):1, preferably (2-5):1.

[0033] According to the method of the present invention, in step (B), the crude product can be separated by first performing gas-liquid separation and then performing distillation separation.

[0034] The gas-liquid separation can be performed in a gas-liquid separation tank under the condition of lowering the temperature without lowering the pressure. The gas-liquid separation temperature is 0°C-100°C, preferably 20°C-80°C, and more preferably 20°C-40°C.

[0035] The gas phase stream obtained after gas-liquid separation is basically synthesis gas. After condensation and / or absorption, the remaining synthesis gas can be circulated to the pre-reactor and / or reactor inlet for repeated use.

[0036] The liquid phase flow after gas-liquid separation can be distilled and separated through a distillation device, the top discharge is a mixed product containing alcohol, alkane and aldehyde, and the bottom obtains a heavy material containing a cobalt-phosphine complex catalyst.

[0037] The distillation separation device can be a vacuum distillation kettle, a distillation tower or a thin film evaporator or other distillation separation devices that can be easily thought of by those skilled in the art. -2 MPa, preferably ≤10 -3 MPa, more preferably ≤10 - 4 MPa, a bottom temperature of 70-200°C; a thin film evaporator pressure ≤10 mmHg, preferably ≤6 mmHg, more preferably ≤1 mmHg, a heating surface temperature of 35-150°C, preferably 40-100°C, more preferably 45-70°C, and a residence time of 1-30 minutes, preferably 1-10 minutes, more preferably 1-2 minutes. If the distillation column is used, the reflux ratio is 1-10:1.

[0038] Preferably, the mixture obtained from the top of the distillation apparatus can be further separated by entering a product distillation column. The product distillation column can be an atmospheric distillation column or a rectification column to produce alkanes, high-purity alcohols, and aldehydes. The pressure can be atmospheric pressure, the reflux ratio can be 1-10:1, and the bottom temperature can be 100°C-300°C, preferably 150°C-200°C.

[0039] Preferably, the product distillation can be performed twice in a first product distillation tower and a second product distillation tower, first distilling out light components such as alkanes, and then distilling out products such as alcohols and aldehydes. The heavy materials discharged from the bottom of the second product distillation tower enter the post-processing reactor.

[0040] Preferably, if the target product is to obtain more alcohol, the obtained mixture of alcohol and aldehyde can be hydrogenated to convert the aldehyde into alcohol.

[0041] According to the method of the present invention, in step (C), when the post-treatment reactor is a tubular reactor, the heavy material containing the catalyst can flow into the tubular reactor from the bottom and out from the top, or from the top and out from the bottom. Synthesis gas and water are simultaneously introduced into the reactor without introducing olefins, so that the heavy material is further decomposed into products such as alcohols and aldehydes. The amount of water introduced is 0.01% to 20% by mass of the solution added to the reactor, preferably 0.1% to 10%, and more preferably 1% to 10%.

[0042] The post-treatment reactor is a tubular reactor with a reaction temperature of 100°C to 250°C, preferably 110°C to 200°C, more preferably 120°C to 190°C; a reaction pressure of 1MPa to 12MPa, preferably 3MPa to 10MPa, more preferably 5MPa to 8MPa; and a residence time of 0.5-20 hours, preferably 1-7 hours.

[0043] The amount of heavy material entering the post-treatment reactor can be determined based on the catalyst activity and product yield, and can generally be 1-20% of the mass of the crude product, preferably 5-15%. The post-treatment reactor can be operated simultaneously with the hydroformylation reaction, or can be started after the hydroformylation reaction has proceeded for a period of time, or can be started intermittently.

[0044] According to the method of the present invention, in step (D), the post-treated material enters a discharge distillation tower, which can be an atmospheric distillation tower or a rectifying tower. Alcohol and other products are distilled overhead and discharged or returned to the product distillation tower. Residual heavy materials are obtained at the bottom of the tower and discharged externally. The distillation tower pressure can be atmospheric pressure, the reflux ratio can be 1-10:1, and the bottom temperature can be 100°C-300°C, preferably 150°C-200°C.

[0045] In a second aspect, the present invention further provides an olefin hydroformylation apparatus, comprising: a pretreatment reactor, a hydroformylation reactor, a gas-liquid separator, a distillation separation apparatus, a post-treatment reactor, an external feed distillation tower, and a feed line for a catalyst solution, synthesis gas, and olefins in the hydroformylation reactor; a line for conveying the reaction product from the hydroformylation reactor to the gas-liquid separator; a line for conveying a liquid phase stream from the gas-liquid separator to the distillation separation apparatus; a line for returning the separated synthesis gas from the gas-liquid separator to the pretreatment reactor and / or the hydroformylation reactor; a line for discharging a mixed product from the distillation apparatus; a line for conveying a catalyst-containing material from the distillation separation apparatus to the post-treatment reactor; a water inlet line for the post-treatment reactor; a line for returning the catalyst-containing material from the distillation separation apparatus to the pretreatment reactor and / or the hydroformylation reactor; a connecting line between the post-treatment reactor and the external feed distillation tower; and discharge lines at the upper and lower portions of the external feed distillation tower.

[0046] According to a preferred embodiment of the present invention, the catalyst solution flows into the bottom of the pretreatment reactor and flows out from the top of the pretreatment reactor. After pretreatment, the catalyst solution and olefins flow into the bottom of the tubular reactor and flow out from the top. The crude reaction product enters the gas-liquid separator, wherein the gas is collected by a cold bath to collect the condensate, and the remaining synthesis gas is circulated to the pretreatment reactor or the hydroformylation reactor for reuse. The liquid enters the distillation separation device and is distilled from the top to obtain a mixed product. Most of the remaining catalyst solution is circulated from the bottom to the prereactor for recycling. A small amount of heavy materials enters from the bottom of the post-treatment reactor and flows out from the top. The materials that have been post-treated in the presence of water and synthesis gas enter the external material distillation tower, and products such as alcohol are obtained from the top of the distillation tower, and the external material containing heavy materials is discharged from the bottom. The alcohol and the like obtained at the top of the external material distillation tower can be directly used as products, or enter the first product distillation tower, or enter the second product distillation tower.

[0047] Preferably, it also includes a product distillation tower, preferably a first product distillation tower and a second product distillation tower, a pipeline for the mixed product to enter the first product distillation tower from the upper part of the distillation separation device, a connecting pipeline between the first product distillation tower and the second product distillation tower, a connecting pipeline between the lower part of the second product distillation tower and the lower part of the post-treatment reactor, and a discharge pipeline from the upper part of the first product distillation tower and the second product distillation tower.

[0048] The product distillation tower can be a still or a rectification tower.

[0049] Preferably, the system further comprises a pipeline for supplying synthesis gas or catalyst to the pre-reactor and / or each reactor, and a feed pipeline for supplying synthesis gas to the post-processing reactor.

[0050] Preferably, the hydroformylation reactor is composed of two or more tubular reactors connected in series.

[0051] Wherein, the distillation separation device can be a still, a rectification tower or a thin film evaporator.

[0052] The external material distillation tower can be a still or a rectifying tower. Preferably, the distilled alcohol and other products are returned to the first product distillation tower.

[0053] Preferably, a hydrogenation device may be further included to further hydrogenate the alcohol and aldehyde obtained from the product distillation tower and the discarded material distillation tower to obtain alcohol with a high yield.

[0054] The present invention has the following advantages:

[0055] 1. The discarded materials containing heavy substances are post-processed, and the heavy by-products will be decomposed into alcohol, aldehyde and other products again, which significantly reduces the amount of discarded materials and reduces waste liquid discharge, is beneficial to environmental protection, and has industrial prospects.

[0056] 2. The catalyst pretreatment process can significantly reduce the decomposition of the cobalt-phosphine catalyst, which is beneficial to the formation of active units of the cobalt-phosphine catalyst, improve the activity and stability of the catalyst, and extend the service life of the catalyst.

[0057] 3. The use of strong solubility solvents can increase the catalyst concentration, lower the reaction temperature, increase the total yield of alcohols and aldehydes, and reduce the formation of alkanes.

[0058] 4. The product separation process is simple, and the selectivity of alcohol and aldehyde is high.

[0059] 5. It is applicable to a wide range of olefin raw materials, especially suitable for the hydroformylation of multi-branched olefins with large steric hindrance. The reaction pressure is low, and the equipment investment and processing costs are significantly reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 This is a preferred embodiment of the present invention.

[0061] 1. Pretreatment reactor; 2. Tubular reactor; 3. Tubular reactor; 4. Gas-liquid separator; 5. Distillation separation device; 6. First product distillation tower; 7. Second product distillation tower; 8. Post-treatment reactor; 9. External material distillation tower. DETAILED DESCRIPTION

[0062] The present invention is further described below by way of examples, but the present invention is not limited thereto.

[0063] The olefin raw material in the embodiment is a commercially available C8 olefin, and its composition is: 75.1% of 2,4,4-trimethyl-1-pentene, 21.2% of 2,4,4-trimethyl-2-pentene, and the rest are multi-branched olefins.

[0064] Catalyst Preparation Example 1

[0065] Cobalt cyclohexanecarboxylate and triphenylphosphine were dissolved in isononanol with a cobalt content of 0.17 wt% and a phosphorus content of 0.17 wt%. The air was completely replaced with synthesis gas H2 / CO (2:1), and CO and H2 gases were introduced to a pressure of 3 MPa. The mixture was stirred at 400 rpm and reacted at 110°C for 20 h to obtain a cobalt-phosphine catalyst solution A1.

[0066] Catalyst Preparation Example 2

[0067] Cobalt cyclohexanecarboxylate and triphenylphosphine were dissolved in isononanol, with a cobalt content of 0.06 wt% and a phosphorus content of 0.04 wt%. The air was completely replaced with synthesis gas H2 / CO (2:1), and CO and H2 gases were introduced to a pressure of 3 MPa. The mixture was stirred at 400 rpm and reacted at 100°C for 20 h to obtain a cobalt-phosphine catalyst solution A2.

[0068] Example 1

[0069] C8 olefin and catalyst solution A1 are respectively delivered from storage tanks to a reactor and a pretreatment reactor using high-pressure metering pumps. The catalyst solution and synthesis gas (CO / H2 molar ratio is 1:2) are mixed in the pretreatment reactor at a temperature of 100°C, a pressure of 8 MPa, and a residence time of 1 hour. After pretreatment, 450 g of the catalyst solution and 302 g of the C8 olefin enter the hydroformylation reactor for a hydroformylation reaction at a temperature of 130°C, a pressure of 8 MPa, and a residence time of 4 hours. The crude reaction product enters a gas-liquid separator, wherein the gas is collected by a cold bath to condense the remaining synthesis gas and is recycled to the pretreatment reactor for reuse. The liquid enters a thin film evaporator at a pressure of 1 mmHg and a heating surface temperature of 60°C. The product evaporated from the thin film evaporator enters a product distillation tower to evaporate the product isononanol. Most of the heavy phase containing the catalyst solution in the thin film evaporator can be recycled to the inlet of the pretreatment reactor and, after pretreatment, enters the hydroformylation reactor for reuse. After the cycle, a small amount (approximately 7% by mass of the crude product) of heavy material enters the post-treatment reactor.

[0070] The organic composition of the heavy matter solution entering the post-treatment reactor is: alkanes < 0.1m%, C8 olefins < 0.2m%, isononanal 1.4m%, the content of major heavy matters with carbon number > 9 is 20.7m%, and the rest is mainly isononanol.

[0071] In a post-processing reactor, water (7% by weight of the solution) was added under a syngas atmosphere. The reaction was carried out at a pressure of 8 MPa and a temperature of 120°C for one hour to decompose the heavy products into products such as isononanol and isononanal. Chromatographic analysis of the reaction products revealed alkanes (less than 0.1% by mass), C8 alkenes (less than 0.1% by mass), isononanal (6.4% by mass), and major heavy products with carbon numbers greater than 9 (5.3% by mass). The remainder was primarily isononanol. The ratio of major heavy products with carbon numbers greater than 9 to the feed to the post-processing reactor was reduced by 74.4%. The post-processed material was distilled into a rectification column, where products such as isononanol and isononanal were distilled off, and the remaining material was discarded.

[0072] Example 2

[0073] Catalyst pretreatment, hydroformylation reaction and crude product separation were the same as in Example 1.

[0074] The organic composition of the heavy material solution entering the post-treatment reactor was the same as in Example 1. Water (7% by weight of the solution) was added to the post-treatment reactor under a syngas atmosphere. The reaction was conducted at a temperature of 120° C. and 8 MPa for 1 hour, and then at a temperature of 150° C. and 8 MPa for 4 hours to decompose the heavy material into products such as isononanol and isononanal. Chromatographic analysis of the reaction products revealed alkanes <0.2 wt%, isononanal 4.0 wt%, and 1.8 wt% of the major heavy materials with carbon numbers >9. The remainder was primarily isononanol. The ratio of the major heavy materials with carbon numbers >9 to the feed to the post-treatment reactor was reduced by 91%.

[0075] The post-treated material enters the distillation tower, and after the products such as isononanol and isononanal are evaporated, the remaining material is discarded.

[0076] Comparative Example 1

[0077] Catalyst pretreatment, hydroformylation reaction and crude product separation were the same as in Example 1.

[0078] The organic composition of the solution containing heavy materials entering the post-processing reactor was the same as in Example 1. The post-processing reactor was maintained at a reaction temperature of 100° C., 8 MPa, and a synthesis gas atmosphere. Water (7% by weight of the solution) was added. After one hour of reaction, chromatographic analysis of the reaction products revealed alkanes <0.1 wt%, C8 alkenes <0.2 wt%, 1.4 wt% isononanal, and 20.5 wt% of the major heavy materials with carbon numbers >9. The remainder was primarily isononanol. After the reaction, the major heavy materials with carbon numbers >9 were essentially the same as those in the post-processing reactor feed ratio, with no increase in isononanol or isononanal. A comparison with Example 1 shows that when the reaction temperature was lowered to 100° C., the heavies were essentially unconverted.

[0079] Example 3

[0080] Catalyst pretreatment, hydroformylation reaction, and crude product separation were performed as in Example 1. The organic composition of the solution containing heavy materials entering the post-processing reactor was the same as in Example 1. Water (7% by weight of the solution) was added to the post-processing reactor under a syngas atmosphere. The reaction was carried out at a reaction pressure of 8 MPa and a reaction temperature of 120°C for 3 hours to decompose the heavy materials into products such as isononanol and isononanal. Chromatographic analysis of the reaction products revealed alkanes <0.1 wt%, C8 olefins <0.1 wt%, isononanal 6.6 wt%, and 4.4 wt% of the major heavy materials with carbon numbers >9. The remainder was primarily isononanol. The feed ratio of the major heavy materials with carbon numbers >9 to the post-processing reactor was reduced by 79%. The post-processed material entered a distillation column, where the isononanol, isononanal, and other products were distilled off, and the remaining material was discarded.

[0081] Comparative Example 2

[0082] Catalyst pretreatment, hydroformylation reaction, and crude product separation were performed as in Example 1. The organic composition of the solution containing the heavies entering the post-processing reactor was identical to that of Example 3. The post-processing reactor was operated under a syngas atmosphere, without the addition of water, at a reaction pressure of 8 MPa and a temperature of 120°C for 3 hours, decomposing the heavies into products such as isononanol and isononanal. Chromatographic analysis of the reaction products revealed alkanes <0.1 wt%, C8 olefins <0.1 wt%, isononanal 6.4 wt%, and 5.98 wt% of the major heavies with carbon numbers >9, with the remainder primarily being isononanol. This indicates that the major heavies with carbon numbers >9 were reduced by 71% in terms of feed ratio to the post-processing reactor. The post-processed material then entered a distillation column, where the isononanol, isononanal, and other products were distilled off, with the remaining material discarded. Compared to Example 3, the conversion of the heavies was lower when no water was added.

[0083] Example 4

[0084] C8 olefin and catalyst solution A2 are respectively fed into the reactor and pretreatment reactor from the storage tank using high-pressure metering pumps. The catalyst solution and synthesis gas (CO / H2 molar ratio is 1:1.5) flow into the tubular pretreatment reactor from the bottom and flow out from the top. The temperature of the pretreatment reactor is 100°C, the pressure is 8MPa, and the residence time is 1 hour. After pretreatment, 83.3g of catalyst solution and 30.2g of C8 olefin enter the hydroformylation reactor. The hydroformylation reactor consists of two tubular reactors in series. The molar ratio of synthesis gas to olefin is 6:1. Olefin and synthesis gas are discharged from the bottom of the reactor. Enter the reactor, flow out from the top, and carry out hydroformylation reaction, the reaction pressure is 8MPa, the reaction temperature is 130℃, and the reaction temperature is 145℃. After the reaction, the crude product enters the gas-liquid separator, and the gas is collected by the cold bath to condense the liquid. The remaining synthesis gas is recycled to the pretreatment reactor for reuse. The liquid enters the thin film evaporator, and the product evaporated by the thin film evaporator enters the product distillation tower to evaporate the product isononanol. Most of the heavy phase containing catalyst solution in the thin film evaporator can be recycled to the inlet of the pretreatment reactor, and after pretreatment, it enters the hydroformylation reactor for repeated use. A small amount of heavy material is discarded and enters the post-treatment reactor.

[0085] The organic composition of the heavies solution entering the post-processing reactor is as follows: alkanes <0.2% by mass, C8 olefins <0.2% by mass, isononanal 5.1% by mass, and major heavies with carbon numbers >9 at 38.8% by mass, with the remainder primarily consisting of isononanol. At a reaction temperature of 180°C, 7 MPa, and a syngas atmosphere, the post-processing reactor is treated with water (4.6% by mass of the solution) to decompose the heavies into products such as isononanol and isononanal. After a six-hour reaction, chromatographic analysis of the reaction products revealed alkanes <0.2% by mass, C8 olefins <0.1% by mass, isononanal 0.1% by mass, and major heavies with carbon numbers >9 at approximately 1.8% by mass, with the remainder primarily consisting of isononanol. The ratio of major heavies with carbon numbers >9 to the post-processing reactor feed is reduced by >95%.

[0086] The post-treated material enters the distillation tower, and after the products such as isononanol and isononanal are evaporated, the remaining material is discarded.

Claims

1. A method for a hydroformylation reaction, comprising the following steps: (A) introducing a cobalt-phosphine complex catalyst solution and an olefin into a hydroformylation reactor to carry out a hydroformylation reaction under a synthesis gas environment; (B) separating the crude reaction product to obtain a mixed product of alcohol, aldehyde and alkane from the light component and a material containing a cobalt-phosphine complex catalyst from the heavy component; (C) Most of the material containing the cobalt-phosphine catalyst is returned to the inlet of the hydroformylation reactor for recycling; a small portion of the heavy material enters a post-treatment reactor, where water is added and post-treated in a synthesis gas atmosphere, wherein the amount of water added is 0.1% to 20% of the mass of the solution in the reactor, and the reaction temperature of the post-treatment reactor is 110° C. to 250° C. and the reaction pressure is 1 MPa to 12 MPa; (D) The outflow material of the post-treatment reactor is subjected to distillation separation, the product is obtained at the top of the tower, and the residual material at the bottom of the tower is discharged from the reactor.

2. The method according to claim 1, wherein Prior to the hydroformylation reaction, the catalyst solution is also pretreated in a pretreatment reactor.

3. The method according to claim 1, wherein The pretreatment is carried out in a synthesis gas atmosphere, the temperature of the pretreatment reactor is 50° C. to 150° C., the pressure is 1 MPa to 12 MPa, and the pretreatment time is 0.1 to 10 hours.

4. The method according to claim 1, wherein The pretreatment is carried out in a synthesis gas atmosphere, the temperature of the pretreatment reactor is 75° C. to 130° C., the pressure is 5 MPa to 8 MPa, and the pretreatment time is 1 to 3 hours.

5. The method according to claim 1, wherein In step (A), the mass concentration of cobalt in the cobalt-phosphine complex catalyst solution is 0.05%-3%.

6. The method according to claim 1, wherein In step (A), the mass concentration of cobalt in the cobalt-phosphine complex catalyst solution is 0.2% to 2%.

7. The method according to claim 1, wherein: In step (A), the mass concentration of cobalt in the cobalt-phosphine complex catalyst solution is 0.5% to 1.5%.

8. The method according to claim 1, wherein In the cobalt-phosphine complex catalyst solution, the mass ratio of cobalt-containing raw material to cobalt and phosphorus of the phosphine ligand is 1:(0.1-3).

9. The method according to claim 1, wherein In the cobalt-phosphine complex catalyst solution, the mass ratio of cobalt-containing raw material to cobalt and phosphorus of the phosphine ligand is 1:(0.2-2).

10. The method according to claim 1, wherein In the cobalt-phosphine complex catalyst solution, the mass ratio of cobalt-containing raw material to cobalt and phosphorus of the phosphine ligand is 1:(0.3-1).

11. The method according to claim 1, wherein The olefin described in step (A) is a C1 to C30 olefin.

12. The method according to claim 1, wherein The olefin described in step (A) is C6-C20 olefin.

13. The method according to claim 1, wherein: In the synthesis gas, the molar ratio of carbon monoxide to hydrogen is 4:1 to 1:

4.

14. The method according to claim 1, wherein In the synthesis gas, the molar ratio of carbon monoxide to hydrogen is 3:1 to 1:

3.

15. The method according to claim 1, wherein In the synthesis gas, the molar ratio of carbon monoxide to hydrogen is 2:1 to 1:

2.

16. The method according to claim 1, wherein The temperature of the hydroformylation reactor is 60° C. to 250° C., and the reaction pressure is 1 MPa to 12 MPa.

17. The method according to claim 1, wherein The temperature of the hydroformylation reactor is 100° C. to 220° C., and the reaction pressure is 2 MPa to 10 MPa.

18. The method according to claim 1, wherein The temperature of the hydroformylation reactor is selected from 110° C. to 140° C.; and the reaction pressure is 5 MPa to 8 MPa.

19. The method according to claim 1, wherein The molar ratio of synthesis gas to olefin is (1-12):1, and the mass ratio of catalyst solution to olefin is (0.1-10):

1.

20. The method according to claim 1, wherein Synthesis gas to olefin molar ratio (3-6): 1; Mass ratio of catalyst solution to olefin (1-6):

1.

21. The method according to claim 1, wherein In step (C), the amount of water added to the post-treatment reactor is 1%-10% of the mass of the solution in the reactor.

22. The method according to claim 1, wherein The post-treatment reactor is a tubular reactor with a reaction temperature of 110° C. to 200° C., a reaction pressure of 3 MPa to 10 MPa, and a residence time of 0.1 to 20 hours.

23. The method according to claim 1, wherein The reaction temperature of the post-treatment reactor is 120° C. to 190° C., the reaction pressure is 5 MPa to 8 MPa, and the residence time is 1 to 7 hours.

24. The method according to claim 1, wherein The amount of the heavy material entering the post-processing reactor is 1 to 20% of the mass of the crude product.

25. The method according to claim 1, wherein The amount of the heavy material entering the post-processing reactor is 5-15% of the mass of the crude product.

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