A cobalt-based catalyst, a preparation method thereof, an aldehyde-forming process and system

Abstract

This invention relates to the field of cobalt-based catalyst preparation technology, specifically to a cobalt-based catalyst and its preparation method, aldehyde formation process, and system. The cobalt-based catalyst preparation method includes the following steps: Step S1, mixing DCPAM ligand, polymerizable monomer, and crosslinking agent at a mass ratio of 1:5:0.5, adding the mixture to an organic solvent, and undergoing a solvothermal polymerization reaction to obtain a POPs support; Step S2, dispersing a cobalt source, DCPAM ligand, and auxiliary agent in a polyether solvent, and introducing syngas, undergoing an activation reaction to obtain an active component dispersion; Step S3, impregnating the active component dispersion into the POPs support at a liquid-to-solid ratio of 5:1 (mL / g), stirring, and drying to obtain a Co-DCPAM / Mo2C@POPs cobalt-based catalyst. This invention can improve the catalytic activity and target product selectivity of cobalt-based catalysts, effectively inhibit the loss of active components, and solve the problem of poor activity of existing cobalt-based catalysts, resulting in a short operating cycle during aldehyde formation.

Description

Technical Field

[0001] This invention relates to the field of cobalt-based catalyst preparation technology, and in particular to a cobalt-based catalyst and its preparation method, aldehyde formation process and system. Background Technology

[0002] Hydroformylation is an α-reaction. The atom-economical reaction of olefins with syngas (CO / H2) to produce aldehydes via catalytic conversion is also a core technology for preparing high-value-added linear aldehydes in fields such as fine chemicals, plasticizers, and surfactants. Long-chain α-aldehydes... Olefins (C6–C) 20 Hydroformylation is used to prepare high-carbon linear aldehydes, which are widely used in the synthesis of high-end polyvinyl chloride plasticizers, high-performance surfactants, lubricant additives and other products due to their high purity and excellent performance.

[0003] Cobalt-based catalysts are advantageous due to their low raw material cost and their effectiveness against long-chain α-phospholipids. Olefins have strong adaptability and have become the preferred choice for long-chain α-olefins in industry. The mainstream catalytic system for olefin hydroformylation. Slurry bed reactors offer advantages such as sufficient gas-liquid-solid three-phase contact, high mass transfer efficiency, and stable temperature and pressure control. They enable suspension of cobalt-based catalysts, continuous reaction, and product separation, making them the preferred reactor form for one-step cobalt-based catalytic aldehyde synthesis. Currently, long-chain α-... Olefin hydroformylation mainly employs cobalt-based homogeneous or supported catalytic systems. The process often uses a slurry bed as the core reactor, and the hydroformylation reaction is completed under high temperature and high pressure conditions. The cobalt-based catalyst is then separated from the product through sedimentation, filtration, or extraction. The cobalt-based catalyst is regenerated and recycled.

[0004] Existing slurry-bed cobalt-based hydroformylation technology generally suffers from key defects such as poor stability of the active center of cobalt-based catalysts and severe loss of metals and ligands. This results in short continuous operation cycles for cobalt-based catalysts and the need for frequent shutdowns for regeneration, making it difficult to meet the requirements of long-term stable industrial production. Summary of the Invention

[0005] The technical problem to be solved by the embodiments of the present invention is to provide a cobalt-based catalyst and its preparation method, aldehyde formation process and system, so as to solve the problem that the cobalt-based catalyst has poor activity in the prior art, resulting in a short operating cycle of the cobalt-based catalyst in the aldehyde formation process.

[0006] In a first aspect, the present invention discloses a method for preparing a cobalt-based catalyst, comprising the following steps: Step S1: Mix DCPAM ligand, polymerizing monomer, and crosslinking agent in a mass ratio of 1:5:0.5, add the mixture to an organic solvent, and perform solvothermal polymerization to obtain the POPs carrier. Step S2: Disperse the cobalt source, DCPAM ligand, and auxiliary agent in a polyether solvent, and introduce syngas to activate the reaction, thereby obtaining a dispersion of the active component. Step S3: The active component dispersion is impregnated in the POPs support at a liquid-to-solid ratio of 5:1 (mL / g), and after stirring and drying, the Co-DCPAM / Mo2C@POPs cobalt-based catalyst is obtained.

[0007] Optionally, in step S1, the polymerizing monomer is styrene, the crosslinking agent is divinylbenzene, the organic solvent is DMF, and the reaction conditions for the solvothermal polymerization reaction are: temperature 120°C, pressure 0.5 MPa, and reaction time 24 h.

[0008] Optionally, in step S2, the cobalt source is cobalt acetate, the auxiliary agent is Mo2C nanoparticles, the polyether solvent is tetraethylene glycol dimethyl ether, the synthesis gas is a mixture of hydrogen and carbon monoxide in a molar ratio of 1.1:1, and the activation reaction conditions are: temperature 100℃, pressure 5MPa, reaction time 2h.

[0009] In a second aspect, the present invention also discloses a cobalt-based catalyst, which is a cobalt-based catalyst prepared based on the preparation method of the cobalt-based catalyst described in the first aspect above.

[0010] Optionally, the cobalt-based catalyst contains 0.5 wt% to 3.0 wt% of cobalt, and the Mo2C nanoparticles contain 0.2 wt% to 1.0 wt% of Mo2C nanoparticles. The molar ratio of DCPAM ligand to cobalt in the cobalt-based catalyst is 1.2 to 1.5:1. The specific surface area of ​​the POPs support in the cobalt-based catalyst is 800 m² / g to 1200 m² / g, and the pore size distribution on the POPs support is 2 nm to 50 nm. The active component of the cobalt-based catalyst is the carbonyl cobalt complex HCo(CO)2(κ). 2 -DCPAM).

[0011] Thirdly, the present invention also discloses a cobalt-based catalyst aldehyde formation process, including the cobalt-based catalyst of the second aspect, and further comprising the following steps: Step S1: Pretreatment of olefins and syngas; Step S2: The pretreated olefins are mixed with syngas, and after adding polyether solvents and cobalt-based catalysts from the second aspect, they are fed into a slurry bed reactor for hydroformylation to obtain a reaction slurry. Step S3: The reaction slurry is separated in the slurry bed reactor. The separated cobalt-based catalyst is retained and returned to the reactor, and the separated filtrate enters the purification unit. Step S4: The filtrate is purified to obtain a linear aldehyde product.

[0012] Optionally, in step S1, the olefin is an α-olefin with a purity ≥98%, and the molar ratio of H2 to CO in the synthesis gas is 1.0 to 1.2:1; in step S2, the polyether solvent is tetraethylene glycol dimethyl ether, and the mass ratio of the polyether solvent to the olefin is 2 to 4:1; the concentration of the cobalt-based catalyst is 3 wt% to 8 wt%, and the feed space velocity is 0.5 h⁻¹. -1 -2.0h -1 The reaction conditions for the hydroformylation reaction are: temperature 110°C to 140°C and pressure 5 MPa to 8 MPa.

[0013] Optionally, in step S2, based on the total mass of the reaction system in the slurry bed reactor, DCPAM ligands are periodically added to the slurry bed reactor, with the amount of DCPAM ligands added being 0.01wt% to 0.05wt%; in step S3, the separated cobalt-based catalyst is activated and regenerated in an activation vessel, and the activation and regeneration conditions for the cobalt-based catalyst are: syngas at a temperature of 120℃ and a pressure of 6MPa is introduced into the activation vessel, and the activation and regeneration time is 3h.

[0014] Optionally, in step S4, the filtrate enters the refining unit and undergoes flash evaporation and distillation to obtain a linear aldehyde product; the flash evaporation conditions are: pressure 0.5 MPa, temperature 80°C, and the distillation conditions are: pressure at atmospheric pressure, temperature 180°C to 220°C.

[0015] Fourthly, a cobalt-based catalyst aldehyde formation system, applicable to the cobalt-based catalyst aldehyde formation process in the third aspect, includes: a pretreatment unit, a slurry bed reactor, a catalyst regeneration unit, and a purification unit. The pretreatment unit includes a dehydration tower and a purification tower. The dehydration tower is used for dehydrating olefins, and the purification tower is used for purifying syngas. The dehydration tower and the purification tower are respectively connected to the slurry bed reactor, which is used for hydroformylation. The catalyst regeneration unit includes an activation vessel and a ligand replenishment tank, which are respectively connected to the slurry bed reactor. The purification unit includes a flash distillation tower and a distillation tower. The flash distillation tower is connected to the slurry bed reactor, and the distillation tower is connected to the flash distillation tower.

[0016] Compared with existing technologies, the beneficial effects of the cobalt-based catalyst aldehyde formation process provided in this invention are as follows: The preparation method of the cobalt-based catalyst of this invention involves a stepwise process of preparing a POPs support, synthesizing an active component dispersion, and impregnating the active component dispersion into the POPs support, ultimately yielding a Co-DCPAM / Mo2C@POPs cobalt-based catalyst. This cobalt-based catalyst preparation method involves mixing DCPAM ligands, polymerizable monomers, and crosslinking agents in a specific ratio and then using a multi-ether solvothermal polymerization method to prepare a structurally stable POPs support, providing sufficient loading sites for the active components. Then, the cobalt source, DCPAM ligands, and additives are activated to form a highly active component dispersion. Finally, precise liquid-to-solid ratio impregnation combined with stirring and drying ensures the active components are firmly loaded, ultimately yielding the Co-DCPAM / Mo2C@POPs cobalt-based catalyst. The overall process is simple and controllable, improving both the catalytic activity and target product selectivity of the cobalt-based catalyst while effectively suppressing the loss of active components. Attached Figure Description

[0017] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. In the accompanying drawings: Figure 1 This is a schematic diagram of the cobalt-based catalyst aldehyde formation system provided in an embodiment of the present invention.

[0018] The labels for the attached figures are as follows: 10. Pretreatment unit; 11. Dehydration tower; 12. Purification tower; 20. Slurry bed reactor; 30. Catalyst regeneration unit; 31. Activation vessel; 32. Ligand replenishment tank; 40. Refining unit; 41. Flash distillation tower; 42. Distillation tower. Detailed Implementation

[0019] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0020] This invention provides a method for preparing a cobalt-based catalyst, such as... Figure 1 As shown, the preparation method of the cobalt-based catalyst includes the following steps: Step S1: Mix DCPAM ligand, polymerizing monomer, and crosslinking agent in a mass ratio of 1:5:0.5, add the mixture to an organic solvent, and perform solvothermal polymerization to obtain the POPs carrier. Step S2: Disperse the cobalt source, DCPAM ligand, and auxiliary agent in a polyether solvent, and introduce syngas to activate the reaction, thereby obtaining a dispersion of the active component. Step S3: The active component dispersion is impregnated in the POPs support at a liquid-to-solid ratio of 5:1 (mL / g), and after stirring and drying, the Co-DCPAM / Mo2C@POPs cobalt-based catalyst is obtained.

[0021] This method for preparing a cobalt-based catalyst involves a stepwise process of preparing a POPs support, synthesizing an active component dispersion, and impregnating the active component dispersion into the POPs support, ultimately yielding a Co-DCPAM / Mo2C@POPs cobalt-based catalyst. The method involves mixing DCPAM ligands, monomers, and crosslinking agents in a specific ratio and then performing solvothermal polymerization with multi-ethers to prepare a structurally stable POPs support, providing ample loading sites for the active component. Then, the cobalt source, DCPAM ligand, and additives are activated to form a highly active component dispersion. Finally, precise liquid-to-solid ratio impregnation combined with stirring and drying ensures the active component is firmly loaded, resulting in the Co-DCPAM / Mo2C@POPs cobalt-based catalyst. The overall process is simple and controllable, improving the catalytic activity and target product selectivity of the cobalt-based catalyst while effectively suppressing the loss of active components.

[0022] In step S1, the DCPAM ligand, monomer, and crosslinking agent are mixed at a mass ratio of 1:5:0.5. This ensures that the ratio of the three raw materials reaches the equilibrium state required for the reaction. A reasonable ratio avoids incomplete polymerization or structural defects in the POPs support caused by imbalances in the raw material proportions. The mixed DCPAM ligand, monomer, and crosslinking agent are then added to an organic solvent. The organic solvent can fully dissolve the DCPAM ligand, monomer, and crosslinking agent, ensuring a uniform distribution of them in the reaction system and eliminating the problem of uneven reaction caused by local aggregation of raw materials. The DCPAM ligand, monomer, and crosslinking agent react under polyether solvothermal polymerization conditions to form a structurally regular and stable POPs support. This POPs support can provide a large number of effective loading sites for the active components in the subsequent active component dispersion, while enhancing the carrying capacity of the POPs support for the active components. This improves the problem of easy loss of active components at the POPs support level and also enhances the overall activity and selectivity of the cobalt-based catalyst.

[0023] It should be noted that DCPAM ligands are bidentate chelate phosphine-amide DCPAM ligands, a class of organic DCPAM ligands containing both phosphine atoms and amide groups. The DCPAM ligand molecule has two sites capable of independently coordinating with a metal center, and can simultaneously connect with a cobalt atom through both sites to form a cyclic chelate structure. The general structural formula of DCPAM ligands is... R is cyclohexyl, biphenyl or bisphenol fluorenyl, preferably bisphenol fluorenyl skeleton R is selected from cyclohexyl, biphenyl or bisphenol fluorenyl.

[0024] Furthermore, in step S1, the monomer is styrene, the crosslinking agent is divinylbenzene, the organic solvent is DMF, and the reaction conditions for the solvothermal polymerization reaction are: a temperature of 120°C and a pressure of 0.5 MPa for 24 hours.

[0025] Specifically, the polymer monomer is styrene. Styrene can form a continuous and stable polymer backbone structure, which can provide basic structural support for the POPs carrier and ensure that the POPs carrier has good structural stability.

[0026] On the other hand, the crosslinking agent is divinylbenzene, which enables the polymer molecular chains to form a crosslinked network structure. This network structure can improve the structural strength of the POPs carrier and simultaneously form a rich porous structure, providing sufficient loading sites for subsequent active components. The DCPAM ligand is mixed with styrene and divinylbenzene in a specific mass ratio, allowing for a fully synergistic reaction of the components during polymerization, avoiding problems such as uneven POPs carrier structure or incomplete polymerization due to imbalanced proportions.

[0027] On the other hand, DMF is N,N-dimethylformamide. As an organic solvent, DMF can fully dissolve DCPAM ligands, styrene and divinylbenzene, so that each raw material is uniformly dispersed in the reaction system, ensuring that the polymerization reaction proceeds synchronously and uniformly in the overall reaction system, and improving the structural uniformity of the POPs carrier.

[0028] It should be noted that the solvothermal polymerization of polyethers involves heating and pressurizing in an organic solvent to polymerize small molecules within the reaction system, transforming them into porous polymer materials. In this embodiment, the solvothermal polymerization conditions for polyethers are mild and controllable, and the preparation process is simple, effectively simplifying the preparation steps of cobalt-based catalysts. The reaction system is continuously subjected to solvothermal polymerization at 120°C and 0.5 MPa for 24 hours, ensuring complete polymerization and forming a stable, well-defined POPs support. This well-defined pore structure facilitates the diffusion and transport of reactants and products, thereby enhancing the catalytic activity and selectivity of the cobalt-based catalyst.

[0029] In step S2, the cobalt source, DCPAM ligand, and auxiliary agent are dispersed in a polyether solvent, ensuring a uniform distribution of these components in the reaction system. Then, syngas is introduced into the reaction system to initiate an activation reaction, promoting the full interaction between the cobalt source, DCPAM ligand, and auxiliary agent, transforming them into a dispersion of highly catalytically active components.

[0030] Specifically, this activation reaction process can enhance the activity of the active components in the active component dispersion, resulting in better stability of the activated active component dispersion, uniform distribution of the active components, improved selectivity of the cobalt-based catalyst, and reduced occurrence of side reactions.

[0031] Further, in step S2, the cobalt source is cobalt acetate, the auxiliary agent is Mo2C nanoparticles, the polyether solvent is tetraethylene glycol dimethyl ether, the synthesis gas is a mixture of hydrogen and carbon monoxide in a molar ratio of 1.1:1, and the activation reaction conditions are: activation reaction for 2 hours at a temperature of 100℃ and a pressure of 5MPa.

[0032] Specifically, cobalt acetate, as a cobalt source, can stably provide cobalt ions in the activation reaction system. These cobalt ions can fully coordinate with the DCPAM ligand, facilitating the formation of structurally uniform catalytic active centers, thereby enhancing the overall catalytic activity of the cobalt-based catalyst. Besides the above-mentioned configuration, cobalt sources can also be cobalt acetylacetonate, cobalt chloride, cobalt nitrate, or cobalt formate.

[0033] On the other hand, Mo2C nanoparticles, as an additive, can synergistically catalyze with the cobalt-based active component, accelerating the catalytic reaction rate and further enhancing the activity of the cobalt-based catalyst. In this embodiment, Mo2C nanoparticles are selected as the additive. Alternatively, tungsten carbide nanoparticles, cobalt phosphide nanoparticles, or nickel phosphide nanoparticles can also be selected.

[0034] On the other hand, tetraethylene glycol dimethyl ether, as a polyether solvent, can uniformly disperse cobalt acetate, bidentate chelated phosphonamide DCPAM ligand, and Mo2C nanoparticles. This polyether solvent can prevent the aggregation of components and ensure that the activation reaction proceeds uniformly and fully. In addition, diethylene glycol dimethyl ether, pentaethylene glycol dimethyl ether, or diethylene glycol diethyl ether can also be selected as polyether solvents.

[0035] Syngas is formed by mixing hydrogen and carbon monoxide in a molar ratio of 1.1:1. Syngas can provide a suitable reducing and coordination atmosphere for the activation process. This ratio of syngas can promote the efficient conversion of cobalt acetate into active cobalt species, while ensuring the structural stability of the active component, reducing the generation of by-products, and improving the selectivity of the target product.

[0036] The reaction system is activated at 100℃ and under set pressure for 2 hours, which allows the activation process to be fully completed. This mild condition will not damage the structure of the DCPAM ligand and the active component, ensuring good stability of the active component dispersion and effectively reducing the risk of loss of the active component during subsequent use.

[0037] In step S3, the active component dispersion and the POPs carrier are impregnated at a liquid-to-solid ratio of 5:1 (mL / g). This ensures that the active component dispersion fully wets the POPs carrier, allowing the active component to fully contact the loading sites on the POPs carrier. This avoids both excessive liquid leading to material waste and insufficient liquid leading to inadequate loading. The liquid-to-solid ratio is the mass ratio of the liquid active component dispersion to the solid POPs carrier.

[0038] The stirring operation further enhances the contact between the active component and the POPs support, ensuring that the active component is uniformly attached to the surface and internal structure of the POPs support. This improves the overall uniformity of the cobalt-based catalyst's performance and further guarantees catalytic selectivity. The drying process removes excess polyether solvents from the reaction system, allowing the active component to form a strong bond with the POPs support and effectively reducing the loss of active component during use. Furthermore, this impregnation-stirring-drying process is simple to operate, shortens the overall preparation cycle, and ultimately yields a Co-DCPAM / Mo2C@POPs cobalt-based catalyst with good structural stability.

[0039] This invention also provides a cobalt-based catalyst, which is prepared by the method described in the foregoing embodiments.

[0040] This cobalt-based catalyst has the same structure and beneficial effects as the cobalt-based catalyst prepared by the method described in the foregoing embodiments. The structure and beneficial effects of the cobalt-based catalyst preparation method have been described in detail in the foregoing embodiments and will not be repeated here.

[0041] Furthermore, the cobalt-based catalyst contains 0.5 wt% to 3.0 wt% of cobalt, and the Mo2C nanoparticles in the cobalt-based catalyst contain 0.2 wt% to 1.0 wt% of Mo2C nanoparticles. The molar ratio of DCPAM ligand to cobalt in the cobalt-based catalyst is 1.2 to 1.5:1. The specific surface area of ​​the POPs support in the cobalt-based catalyst is 800 m² / g to 1200 m² / g, the pore size distribution on the POPs support is 2 nm to 50 nm, and the active component of the cobalt-based catalyst is HCo(CO)2(κ). 2 -DCPAM).

[0042] HCo(CO)2(κ 2 -DCPAM, as the active component of cobalt-based catalysts, can form structurally stable bidentate chelate coordination centers. This active component can provide efficient and specific catalytic sites for hydroformylation reactions, thereby enhancing the catalytic activity of cobalt-based catalysts and reducing the occurrence of side reactions.

[0043] Specifically, the cobalt content is controlled between 0.5 wt% and 3.0 wt% to ensure that the cobalt-based catalyst has a sufficient number of active sites. This content range can avoid insufficient catalytic activity caused by too low a cobalt content, and also prevent the agglomeration of active components caused by too high a cobalt content, thereby ensuring a balance between catalytic activity and selectivity.

[0044] The content of Mo2C nanoparticles is controlled between 0.2 wt% and 1.0 wt%, which allows the Mo2C nanoparticles and cobalt-based active components to fully exert their synergistic catalytic effect. This content range ensures that the Mo2C nanoparticles are uniformly dispersed, effectively improving the overall catalytic activity, while preventing the active sites from being covered by excessive Mo2C nanoparticle content, thus ensuring the stability of the overall performance of the cobalt-based catalyst.

[0045] Maintaining a DCPAM ligand to cobalt molar ratio of 1.2 to 1.5:1 ensures that the DCPAM ligand fully encapsulates and stabilizes the cobalt active site. This ratio guarantees that all cobalt atoms form a stable chelate structure, reducing the loss of cobalt active components during the reaction and improving catalytic selectivity.

[0046] The specific surface area of ​​the POPs support is controlled between 800 m² / g and 1200 m² / g, providing a large number of loading sites for the active components. This specific surface area range ensures high dispersion of the active components, improves the utilization rate of active sites, and thus enhances the overall catalytic activity of the cobalt-based catalyst. The pore size distribution of the POPs support is controlled between 2 nm and 50 nm, forming suitable mass transfer channels. This pore size range is conducive to the rapid diffusion of reactants and products, improving reaction efficiency, and effectively restricts the migration and aggregation of active components, further inhibiting the loss of active components and extending the service life of the cobalt-based catalyst.

[0047] This invention also provides a cobalt-based catalyst aldehyde formation process, including the cobalt-based catalyst in the foregoing embodiments, and further including the following steps: Step S1: Pretreatment of olefins and syngas; Step S2: The pretreated olefins are mixed with syngas, and after adding polyether solvents and the cobalt-based catalyst from the previous examples, they are fed into a slurry bed reactor 20 for hydroformylation to obtain a reaction slurry. Step S3: The reaction slurry is separated in the slurry bed reactor 20. The separated cobalt-based catalyst is retained and returned to the slurry bed reactor 20, and the separated filtrate enters the purification unit 40. Step S4: The filtrate is purified in unit 40 to obtain a linear aldehyde product.

[0048] This cobalt-based catalyst aldehyde production process addresses the core challenges of existing technologies, such as insufficient activity, low selectivity, severe loss, and lengthy processes, through a continuous process including pretreatment, slurry-bed hydroformylation, cobalt-based catalyst separation and reuse, product purification, DCPAM ligand replenishment, and cobalt-based catalyst regeneration. Pretreatment ensures the purity of the reaction raw materials to protect the cobalt-based catalyst; slurry-bed reaction improves reaction efficiency and product selectivity; cobalt-based catalyst separation and reuse reduces loss and costs; product purification ensures product quality; and DCPAM ligand replenishment and cobalt-based catalyst regeneration maintain long-term process stability. Overall, this process achieves efficient, stable, and low-cost continuous production of linear aldehydes.

[0049] In step S1, the pretreatment operation accurately removes moisture, mechanical impurities from the olefin, and harmful impurities such as sulfides and inert gases from the syngas. This prevents impurities from interacting with the active sites of the cobalt-based catalyst, thus avoiding poisoning and deactivation of the catalyst. Simultaneously, it prevents impurities from participating in side reactions, ensuring the smooth progress of the subsequent hydroformylation reaction from the source. This lays the raw material foundation for the generation of high-purity straight-chain aldehydes, while also extending the service life of the cobalt-based catalyst and reducing its replacement frequency. Furthermore, in step S1, the olefin is an α-olefin with a purity ≥98%, and the molar ratio of H2 to CO in the syngas is 1.0 to 1.2:1.

[0050] In this embodiment, α-olefins with a purity ≥98% are used as reactants. This reduces the interference of impurities on the reaction, avoids the decrease in catalytic activity caused by impurities binding to the active sites of the cobalt-based catalyst, ensures the directionality of the reaction, reduces side reactions, increases the yield of straight-chain aldehydes, and ensures the stability of the reaction system. Preferably, the α-olefin is C6-C. 20 α-olefins.

[0051] In this embodiment, the molar ratio of H2 to CO in the synthesis gas is controlled at 1.0 to 1.2:1. This ratio can provide a suitable reaction atmosphere for the hydroformylation reaction of α-olefins, ensuring the full conversion of raw materials and avoiding side reactions caused by excess of a single gas, thereby further improving the selectivity of the hydroformylation reaction.

[0052] In step S2, the slurry bed reactor 20 possesses excellent material mixing performance, enabling pretreated olefins, syngas, polyether solvents, and cobalt-based catalysts to fully contact, significantly reducing mass transfer resistance, accelerating the hydroformylation reaction rate, and improving the conversion rate of olefins and syngas. Simultaneously, the slurry bed reactor 20 has high heat transfer efficiency, which can stably control the reaction temperature, avoiding excessively high local temperatures that could lead to decreased activity of the cobalt-based catalyst and increased byproducts. This further enhances the selectivity of the cobalt-based catalyst for straight-chain aldehydes, reduces the formation of byproducts such as branched-chain aldehydes, and improves the yield of the target product.

[0053] Further, in step S2, the polyether solvent is tetraethylene glycol dimethyl ether, and the mass ratio of the polyether solvent to the α-olefin is 2 to 4:1; the concentration of the cobalt-based catalyst is 3 wt% to 8 wt%, and the feed space velocity is 0.5 h⁻¹. -1 Up to 2.0h -1 The hydroformylation reaction is carried out at a temperature of 110℃ to 140℃ and a pressure of 5MPa to 8MPa.

[0054] Using tetraethylene glycol dimethyl ether as a polyether solvent can achieve uniform dispersion of α-olefins, cobalt-based catalysts and promoters, avoid agglomeration of active components, ensure the stability of the reaction system, provide a good medium environment for catalytic reaction, and help the active components to play a full role.

[0055] The concentration of cobalt-based catalyst is controlled between 3 wt% and 8 wt%. This concentration ensures that the reaction has sufficient active sites to ensure efficient reaction, while avoiding the waste of raw materials and the increase of side reactions caused by excessive cobalt-based catalyst, thus achieving a balance between catalytic efficiency and cost.

[0056] Furthermore, in step S2, based on the total mass of the reaction system in the slurry bed reactor 20, DCPAM ligands are periodically added to the slurry bed reactor 20, with the amount of DCPAM ligands added being 0.01wt% to 0.05wt%.

[0057] Regularly replenishing DCPAM ligands can compensate for the loss of DCPAM ligands during the reaction process, maintain the molar ratio of DCPAM ligands to cobalt in the reaction system, ensure the stability of the active center structure of the cobalt-based catalyst, and avoid the loss of active components and the decline in catalytic activity due to insufficient DCPAM ligands.

[0058] The above design can efficiently maintain the activity of cobalt-based catalysts, extend their service life, ensure the continuous and stable operation of the aldehyde formation process, further solve the problems of rapid activity decay, severe loss of active components, and poor process continuity of cobalt-based catalysts, and at the same time realize the efficient utilization of DCPAM ligands and cobalt-based catalysts, reducing production and maintenance costs.

[0059] The amount of DCPAM ligand replenishment is controlled between 0.01wt% and 0.05wt%. This replenishment amount can accurately match the natural loss of DCPAM ligand during the reaction process, and can maintain the stable structure of the active center of the cobalt-based catalyst for a long time, ensuring that the catalytic activity and selectivity are always in a good state.

[0060] It should be noted that hydroformylation, also known as carbonyl synthesis, refers to the organic synthesis reaction in which an olefin and syngas are reacted with a transition metal catalyst to simultaneously introduce a hydrogen atom and a formyl group into the double bond, generating an ortho-aldehyde and an iso-aldehyde with one more carbon atom than the original olefin; the atom economy of this reaction is close to 100%.

[0061] The feed space velocity (FSV) refers to the ratio of the volume of feed entering the slurry bed reactor 20 per unit time to the volume of the catalyst bed within the slurry bed reactor 20. In this embodiment, the FSV is controlled at 0.5 h⁻¹. - ¹ to 2.0h - ¹ This ensures that the reaction proceeds fully, preventing unreacted raw materials from being discharged. It also prevents insufficient contact between the reactants and the cobalt-based catalyst due to excessively high space velocity, while avoiding the problems of lengthy processes and low production efficiency caused by excessively low space velocity.

[0062] In step S3, the reaction slurry is separated in situ within the slurry bed reactor 20, eliminating the need for additional separation equipment, simplifying the process, shortening the production cycle, and reducing equipment investment costs. The cobalt-based catalyst is retained and directly returned to the slurry bed reactor 20 for reuse, eliminating the need for complex separation and purification processes, minimizing the loss of cobalt-based catalyst, reducing the amount of fresh cobalt-based catalyst to be replenished, and preventing cobalt-based catalyst from entering the purification unit 40 with the filtrate and causing product contamination, thus ensuring the smooth operation of subsequent purification processes. Further, the reaction slurry undergoes in-situ separation via a ceramic membrane separator built into the slurry bed reactor 20. The cobalt-based catalyst is retained and returned to the slurry bed reactor 20 for recycling, while the separated filtrate enters the purification unit 40.

[0063] Further, in step S3, the separated cobalt-based catalyst is activated and regenerated and then transported to the slurry bed reactor 20. The regeneration conditions of the cobalt-based catalyst are to introduce synthesis gas at a temperature of 120°C and a pressure of 6 MPa into the activation vessel 31, and the activation time is 3 hours.

[0064] After activation and regeneration, the cobalt-based catalyst is returned to the slurry bed reactor 20, which can effectively restore the activity of the deactivated cobalt-based catalyst. This eliminates the need for frequent shutdowns to replace the cobalt-based catalyst, ensuring continuous operation of the process, improving the operational stability and production efficiency of the unit, and further extending the service life of the cobalt-based catalyst, thereby reducing production and maintenance costs.

[0065] In the above setup, the temperature of 120°C promotes the desorption of byproducts adsorbed on the surface of the cobalt-based catalyst and simultaneously activates the deactivated cobalt active centers; the high-pressure syngas of 6 MPa strengthens the reducing atmosphere, promoting the re-conversion of deactivated cobalt species into highly catalytically active HCo(CO)2(κ) 2-DCPAM) active components repair the active sites of cobalt-based catalysts; the 3-hour activation time ensures that the activation reaction is fully carried out, avoiding both insufficient activation time leading to incomplete recovery of cobalt-based catalyst activity and excessive activation time causing structural damage and loss of active components, thus achieving efficient and stable recovery of cobalt-based catalyst activity.

[0066] In step S4, the refining unit 40 can specifically remove unreacted olefins, syngas, polyether solvents, and a small amount of by-products from the filtrate, achieving efficient separation of linear aldehyde products from impurities, improving the purity of linear aldehyde products, and meeting the requirements for industrial-grade products. At the same time, unreacted raw materials and polyether solvents can be recovered during the refining process, realizing the recycling of raw materials, improving raw material utilization, reducing material waste in the production process, and further controlling production costs.

[0067] Further, in step S4, the filtrate enters the refining unit 40 and undergoes flash evaporation and distillation to obtain a linear aldehyde product. The flash evaporation conditions are: a pressure of 0.5 MPa and a temperature of 80°C. The distillation conditions are: a pressure of atmospheric pressure and a temperature of 180°C to 220°C.

[0068] Specifically, the flash evaporation process employs parameters designed for a cobalt-based catalyst at 0.5 MPa pressure and 80°C, enabling rapid separation of unreacted raw materials, polyether solvents, and trace impurities from the filtrate. Simultaneously, it achieves preliminary separation of light components from the target product, eliminating the need for additional separation equipment, simplifying the operation, and avoiding process redundancy. The flash evaporation process is gentle, does not damage the structure of the target product, and does not cause additional loss of active components.

[0069] The distillation process utilizes atmospheric pressure and reaction conditions ranging from 180°C to 220°C. These conditions ensure accurate and complete separation of linear aldehydes from other impurities and unreacted raw materials. Atmospheric pressure operation eliminates the need for complex high-pressure equipment, reducing production difficulty and equipment investment costs. Simultaneously, the cobalt-based catalyst's temperature range of 180°C to 220°C guarantees successful separation of linear aldehydes, improving the purity of the product and meeting the quality requirements of industrial production.

[0070] Specifically, the step-by-step processing of flash evaporation and distillation forms an efficient product purification process that eliminates the need for complex separation steps. Flash evaporation first achieves coarse separation, removing most of the light component impurities, and then distillation further purifies the product, improving purification efficiency while avoiding the impact of impurities on product quality and ensuring that the final linear aldehyde product meets purity standards.

[0071] In summary, DCPAM ligands, through a triple effect of bidentate chelation, electronic effect regulation, and steric hindrance orientation, synergistically interact with Mo2C nanoparticles at the interface, resulting in cobalt-based catalysts with activity 5 to 8 times that of traditional cobalt-based catalysts. The single-pass conversion rate of α-olefins is ≥92%, the yield of straight-chain aldehydes is ≥90%, the N / I ratio reaches 25 to 35:1, and the side reaction rate is <3%. The reaction temperature is reduced to 110℃ to 140℃, and the pressure is reduced to 5MPa to 8MPa, resulting in a 40% reduction in energy consumption compared to traditional processes, and a significant reduction in equipment investment and operating costs. Integrated continuous operation of "pretreatment, reaction, separation, regeneration, and purification" is achieved, shortening the process flow by 60%, with an online catalyst circulation rate >99.5%, and a continuous operation cycle ≥1000h. The purity of the straight-chain aldehyde product is ≥98.5%, and the process is compatible with C6-C. 20 Full-carbon chain α-olefins. Cobalt-based catalysts are low-cost, DCPAM ligands can be replenished, catalyst loss rate is <0.1%, syngas is recycled, feedstock utilization rate is >95%, and there are no harmful waste emissions.

[0072] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to specific embodiments and comparative examples. However, the scope of protection of this invention is not limited thereto.

[0073] Example 1 Preparation of cobalt-based catalyst: 10g of DCPAM ligand (R is bisphenol fluorenyl), 50g of styrene, and 5g of divinylbenzene were weighed and added to 50mL of LDM. The mixture was then subjected to solvothermal polymerization of a polyether at 120℃ and 0.5MPa for 24h in a reactor. After washing and drying, a POPs support was obtained. 2g of cobalt acetate, 3g of DCPAM ligand, and 0.3g of Mo2C nanoparticles were weighed and dispersed in 100g of tetraethylene glycol dimethyl ether. Synthesis gas (H2 / CO = 1.1 / 1) was introduced, and the mixture was activated at 100℃ and 5MPa for 2h to obtain a dispersion of the active components. The dispersion was impregnated onto the POPs support at a liquid-to-solid ratio of 5:1, stirred at 60℃ for 4h, and vacuum dried at 80℃ for 10h to obtain a Co-DCPAM / Mo2C@POPs cobalt-based catalyst (cobalt content 1.5wt%, Mo2C content 0.3wt%).

[0074] Process Operation: Using 1-octene as raw material, syngas (H2 / CO = 1.1 / 1), tetraethylene glycol dimethyl ether (mass ratio to 1-octene 3:1), and cobalt-based catalyst (concentration 5wt%) are fed into a microbubble-enhanced slurry bed reactor 20. Reaction conditions: temperature 125℃, pressure 6MPa, space velocity 1.0 h⁻¹. -1 The synthesis gas recirculation ratio is 60%. The reaction slurry is filtered through a ceramic membrane, and the filtrate is subjected to flash evaporation (0.5 MPa, 80℃) and distillation (atmospheric pressure, 200℃) to obtain nonanal.

[0075] Test results: 1-Octoene conversion rate 94.2%, nonanal yield 91.5%, normal / isononanal ratio 32:1, by-product percentage 2.3%, cobalt-based catalyst loss rate 0.08%, and stable activity after 1200 hours of continuous operation.

[0076] Example 2 Preparation of cobalt-based catalyst: Same as in Example 1, a cobalt-based catalyst (cobalt content 2.0 wt%, Mo2C content 0.5 wt%) was obtained.

[0077] Process operation: Using 1-dodecene as raw material, the reaction mixture consisted of syngas (H2 / CO = 1.2 / 1), tetraethylene glycol dimethyl ether (4:1 mass ratio to 1-dodecene), and a cobalt-based catalyst concentration of 6 wt%. Reaction conditions: 130℃, 7 MPa, space velocity 1.5 h⁻¹. -1 The cycle ratio is 70%. The rest is the same as in Example 1.

[0078] Test results: 1-Dodecene conversion rate 92.8%, tridecanal yield 90.1%, normal / isodecanal ratio 28:1, byproduct percentage 2.7%, cobalt-based catalyst loss rate 0.09%, recycling rate 99.6%, and stable activity after 1000 hours of operation.

[0079] Example 3 Preparation of cobalt-based catalyst: Same as in Example 1, except that the R group of the DCPAM ligand is replaced with a cyclohexyl group to obtain a cobalt-based catalyst (cobalt content 1.0 wt%, Mo2C content 0.2 wt%).

[0080] Process operation: Using 1-hexene as raw material, the reaction conditions are: syngas (H2 / CO = 1.0 / 1), tetraethylene glycol dimethyl ether (mass ratio to 1-hexene 2:1), and cobalt-based catalyst concentration 3wt%. Reaction conditions: 110℃, 5MPa, space velocity 0.5h⁻¹. - ¹, the cycle ratio is 50%. The rest is the same as in Example 1.

[0081] Test results: 1-hexene conversion rate 92.1%, heptanal yield 90.3%, normal / isoheptanal ratio 25:1, by-product percentage 1.8%, cobalt-based catalyst loss rate 0.07%, and stable activity after 1100 hours of operation.

[0082] Comparative Example 1 (Conventional phosphine DCPAM ligand cobalt-based catalyst) Preparation of cobalt-based catalyst: Co2(CO)8 and PPh3 were mixed in a molar ratio of 1:2, dispersed in tetraethylene glycol dimethyl ether, and impregnated in SiO2POPs support to obtain Co-PPh3 / SiO2 cobalt-based catalyst (cobalt content 1.5wt%).

[0083] Process operation: Using 1-octene as raw material, the reaction conditions were adjusted to a temperature of 160℃ and a pressure of 20MPa, and the rest were the same as in Example 1.

[0084] Test results: 1-Octoene conversion rate 78.5%, nonanal yield 72.3%, positive-to-iso ratio 6:1, by-product percentage 14.7%, cobalt-based catalyst loss rate 1.2%, conversion rate dropped below 65% after 200 hours of operation.

[0085] Comparative Example 2 (without Mo2C additive) Preparation of cobalt-based catalyst: Same as in Example 1, but without adding Mo2C nanoparticles, to obtain Co-DCPAM@POPs cobalt-based catalyst (cobalt content 1.5wt%).

[0086] Process operation: Same as in Example 1.

[0087] Test results: 1-Octoene conversion rate 85.3%, nonanal yield 82.1%, positive-to-sine ratio 22:1, by-product percentage 3.2%, cobalt-based catalyst loss rate 0.09%, and activity began to decline after 800 hours of operation.

[0088] Table 1: Comparison of Data Between Examples and Comparative Examples The data in Table 1 show that the Co-DCPAMMo2C@POPs cobalt-based catalyst developed in this application achieves a comprehensive leap in catalytic performance compared to the traditional Co-PPh3 / SiO2 catalyst and the Mo2C-free Co-DCPAM@POPs catalyst: Firstly, in the reaction of different carbon chain terminal alkene feedstocks such as 1-octene, 1-dodecene, and 1-hexene, this catalyst can achieve a feedstock conversion rate of 92.1% to 94.2% and a target product yield of 90.1% to 91.5% under mild conditions of 110℃ to 130℃ and 5MPa to 7MPa. This is far superior to the 78.5% conversion rate and 72.3% yield achieved by traditional catalysts under harsh conditions of 160℃ / 20MPa, and is also significantly higher than the 85.3% conversion rate and 82.1% yield achieved by Mo2C-free catalysts.

[0089] Secondly, its product positive-to-negative ratio can reach 25:1 to 32:1, and the by-product ratio is only 1.8% to 2.7%, which is a significant improvement over the traditional catalyst with a positive-to-negative ratio of 6:1 and a by-product ratio of 14.7%, resulting in a significant increase in atom utilization.

[0090] Third, the catalyst exhibits a metal loss rate as low as 0.07% to 0.09% and an operating cycle of 1000 to 1200 hours, which is 5 to 6 times longer than the 200-hour operating cycle of traditional catalysts and significantly longer than the 800-hour operating cycle of catalysts without Mo2C. This demonstrates a substantial improvement in stability and lifespan, fully reflecting the synergistic effect of the Mo2C component and the POPs support. It also verifies the technical advantages of this catalyst in terms of activity, selectivity, stability, and mild process.

[0091] This invention also provides a cobalt-based catalyst aldehyde formation system, such as... Figure 1 As shown, the cobalt-based catalyst aldehyde conversion process applicable to the foregoing embodiments includes: a pretreatment unit 10, a slurry bed reactor 20, a catalyst regeneration unit 30, and a purification unit 40. The pretreatment unit 10 includes a dehydration tower 11 and a purification tower 12. The dehydration tower 11 is used for dehydrating olefins, and the purification tower 12 is used for purifying syngas. The dehydration tower 11 and the purification tower 12 are respectively connected to the slurry bed reactor 20, which is used for hydroformylation reaction. The catalyst regeneration unit 30 includes an activation vessel 31 and a ligand replenishment tank 32, which are respectively connected to the slurry bed reactor 20. The purification unit 40 includes a flash evaporator 41 and a distillation tower 42. The flash evaporator 41 is connected to the slurry bed reactor 20, and the distillation tower 42 is connected to the flash evaporator 41.

[0092] The pretreatment unit 10 includes a dehydration tower 11 and a purification tower 12. The dehydration tower 11 is specifically designed to dehydrate olefins, removing both free and bound water to prevent moisture from entering the reaction system and causing side reactions. It also prevents moisture from damaging the active structure and coordination state of the cobalt-based catalyst. The purification tower 12 is specifically designed to purify the syngas, removing toxic components such as sulfides and oxygen-containing impurities to prevent these substances from poisoning the cobalt active centers. This ensures the long-term stable operation of the cobalt-based catalyst from the feedstock inlet, extending its overall lifespan. The specialized functions of these two units improve feedstock pretreatment efficiency, reduce subsequent reaction fluctuations, and enhance process stability.

[0093] The slurry bed reactor 20 is directly connected to the dehydration tower 11 and the purification tower 12, allowing pretreated olefins and syngas to quickly enter the reaction environment and reducing secondary pollution during material transportation. The slurry bed reactor 20 exhibits uniform material mixing and excellent mass and heat transfer, ensuring sufficient contact between the reactants and the cobalt-based catalyst, thus improving olefin conversion and linear aldehyde selectivity. The built-in separation structure of the slurry bed reactor 20 retains the cobalt-based catalyst and enables internal circulation, reducing catalyst leakage and simplifying the configuration of external separation equipment, resulting in a more compact and streamlined overall system layout.

[0094] It should be noted that the slurry bed reactor 20 is a microbubble-enhanced slurry bed reactor 20, which incorporates a microbubble distributor, a tube-and-shell heat exchanger, a three-phase separator, and a ceramic membrane separator. The microbubble-enhanced slurry bed reactor 20 is a high-efficiency slurry bed reactor 20 that, based on a conventional slurry bed reactor 20, uses a microbubble distributor to break the syngas into a large number of micron-sized microbubbles, resulting in a high degree of dispersion of the gas phase in the liquid phase, increasing the gas-liquid contact area, and enhancing mass transfer efficiency. Specifically, the microbubble distributor is mainly used to disperse the introduced syngas into micron-sized microbubbles. The tube-and-shell heat exchanger is mainly used to remove the heat released by the hydroformylation reaction and stabilize the internal temperature of the slurry bed reactor 20. The three-phase separator is mainly used for in-situ preliminary separation of the gas, liquid, and solid phases within the slurry bed reactor 20. The ceramic membrane separator utilizes the sieving effect of the ceramic membrane to precisely retain cobalt-based catalyst solid particles.

[0095] The microbubble distributor has a pore size of 50μm to 200μm; the ceramic membrane separator has a ceramic membrane pore size of 0.1μm to 0.5μm; the microbubble-enhanced slurry bed reactor 20 is made of Hastelloy alloy, has a volume of 1m³ to 10m³, a design pressure of 10MPa, and a design temperature of 200℃; the tube heat exchanger is coupled with the microbubble distributor to control the temperature difference inside the reactor within ±1℃.

[0096] The catalyst regeneration unit 30 is equipped with an activation vessel 31 and a ligand replenishment tank 32, both of which are connected to the slurry bed reactor 20. This allows for online replenishment and regeneration of the cobalt-based catalyst and DCPAM ligands without disassembling the slurry bed reactor 20 or shutting down the reactor for replacement. The ligand replenishment tank 32 can accurately and quantitatively replenish DCPAM ligands, maintaining a stable ratio of DCPAM ligands to cobalt in the reaction system, ensuring the integrity of the active center structure, and further reducing the loss of active components. The activation vessel 31 provides an independent and stable regeneration environment for the deactivated cobalt-based catalyst, restoring its activity under set syngas atmosphere and temperature / pressure conditions. The regenerated cobalt-based catalyst can be directly returned to the slurry bed reactor 20 for continued use. The catalyst regeneration unit 30 enables the recycling and reuse of the cobalt-based catalyst, reducing its consumption, lowering production costs, and ensuring long-term continuous operation of the system, thereby improving overall production efficiency.

[0097] It should be noted that the catalyst regeneration unit 30 also includes a membrane separation component, which is linked with the ceramic membrane separator. The linkage between the membrane separation component and the ceramic membrane separator means that they cooperate and work together in the system to form a continuous cobalt-based catalyst separation and reuse loop.

[0098] The refining unit 40 employs a series connection of a flash distillation column 41 and a distillation column 42. The flash distillation column 41 is directly connected to the slurry bed reactor 20, enabling rapid reception of the reaction filtrate and preliminary separation of light components from the target product, reducing the load on subsequent distillation. The distillation column 42, connected to the flash distillation column 41, allows for deep separation of the crude product at atmospheric pressure and suitable temperature, removing residual impurities and byproducts to obtain high-purity straight-chain aldehydes. This dual-column, stepwise refining design improves separation efficiency, reduces overall energy consumption, and avoids insufficient product purity due to incomplete separation in a single unit. This unit seamlessly integrates with the reaction system, eliminating unnecessary intermediate steps, further simplifying the process flow and enhancing product quality stability.

[0099] It should be noted that the refining unit 40 also includes a tail gas recovery system, which is connected to both the flash distillation tower 41 and the slurry bed reactor 20. The tail gas recovery system is mainly used to recover, treat, and recycle unreacted syngas and a small amount of light component tail gas. The unreacted syngas recycling ratio is 50% to 80%.

[0100] In addition, the cobalt-based catalyst aldehyde conversion system also includes a product storage tank for storing linear aldehyde products, and the product storage tank is connected to the distillation column 42.

[0101] It should be understood that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Those skilled in the art can modify the technical solutions described in the above embodiments, or make equivalent substitutions for some of the technical features; and all such modifications and substitutions should fall within the protection scope of the appended claims of the present invention.

Claims

1. A method for preparing a cobalt-based catalyst, characterized in that, Includes the following steps: Step S1: Mix DCPAM ligand, polymerizing monomer, and crosslinking agent in a mass ratio of 1:5:0.5, add the mixture to an organic solvent, and perform solvothermal polymerization to obtain the POPs carrier. Step S2: Disperse the cobalt source, DCPAM ligand, and auxiliary agent in a polyether solvent, and introduce syngas to activate the reaction, thereby obtaining a dispersion of the active component. Step S3: The active component dispersion is impregnated in the POPs support at a liquid-to-solid ratio of 5:1 (mL / g), and after stirring and drying, the Co-DCPAM / Mo2C@POPs cobalt-based catalyst is obtained.

2. The method for preparing the cobalt-based catalyst according to claim 1, characterized in that, In step S1, the monomer is styrene, the crosslinking agent is divinylbenzene, the organic solvent is DMF, and the reaction conditions for the solvothermal polymerization reaction are: temperature 120℃, pressure 0.5MPa, and reaction time 24h.

3. The method for preparing the cobalt-based catalyst according to claim 1, characterized in that, In step S2, the cobalt source is cobalt acetate, the auxiliary agent is Mo2C nanoparticles, the polyether solvent is tetraethylene glycol dimethyl ether, the synthesis gas is a mixture of hydrogen and carbon monoxide in a molar ratio of 1.1:1, and the activation reaction conditions are: temperature 100℃, pressure 5MPa, reaction time 2h.

4. A cobalt-based catalyst, characterized in that, The cobalt-based catalyst is a cobalt-based catalyst prepared according to the preparation method of the cobalt-based catalyst according to any one of claims 1-3.

5. The cobalt-based catalyst according to claim 4, characterized in that, The cobalt-based catalyst contains 0.5 wt% to 3.0 wt% cobalt, 0.2 wt% to 1.0 wt% Mo2C nanoparticles, and a DCPAM ligand to cobalt molar ratio of 1.2 to 1.5:

1. The POPs support in the cobalt-based catalyst has a specific surface area of ​​800 m² / g to 1200 m² / g and a pore size distribution of 2 nm to 50 nm. The active component of the cobalt-based catalyst is a cobalt carbonyl complex HCo(CO)₂(κ). 2 -DCPAM).

6. A process for aldehyde formation using a cobalt-based catalyst, characterized in that, The cobalt-based catalyst, including that described in claim 4 or 5, further includes the following steps: Step S1: Pretreatment of olefins and syngas; Step S2: The pretreated olefins are mixed with syngas, and after adding a polyether solvent and the cobalt-based catalyst as described in claim 4 or 5, they are fed into a slurry bed reactor for hydroformylation to obtain a reaction slurry. Step S3: The reaction slurry is separated in the slurry bed reactor. The separated cobalt-based catalyst is retained and returned to the reactor, and the separated filtrate enters the purification unit. Step S4: The filtrate is purified to obtain a linear aldehyde product.

7. The aldehyde formation process using a cobalt-based catalyst according to claim 6, characterized in that, In step S1, the olefin is an α-olefin with a purity ≥98%, and the molar ratio of H2 to CO in the synthesis gas is 1.0 to 1.2:1; In step S2, the polyether solvent is tetraethylene glycol dimethyl ether, the mass ratio of the polyether solvent to the olefin is 2 to 4:1, the concentration of the cobalt-based catalyst is 3 wt% to 8 wt%, and the feed space velocity is 0.5 h⁻¹. -1 -2.0h -1 The reaction conditions for the hydroformylation reaction are: temperature 110°C to 140°C and pressure 5 MPa to 8 MPa.

8. The aldehyde formation process using a cobalt-based catalyst according to claim 6, characterized in that, In step S2, based on the total mass of the reaction system in the slurry bed reactor, DCPAM ligands are periodically replenished into the slurry bed reactor at a rate of 0.01 wt% to 0.05 wt%. In step S3, the separated cobalt-based catalyst is activated and regenerated in an activation vessel. The activation and regeneration conditions for the cobalt-based catalyst are as follows: synthesis gas at a temperature of 120°C and a pressure of 6 MPa is introduced into the activation vessel, and the activation and regeneration time is 3 hours.

9. The aldehyde formation process using a cobalt-based catalyst according to claim 6, characterized in that, In step S4, the filtrate enters the refining unit and undergoes flash evaporation and distillation to obtain a linear aldehyde product. The flash evaporation conditions are: pressure 0.5 MPa, temperature 80°C, and the distillation conditions are: pressure at atmospheric pressure, temperature between 180°C and 220°C.

10. A cobalt-based catalyst aldehyde formation system, characterized in that, The cobalt-based catalyst aldehyde formation process according to any one of claims 6-9 comprises: The pretreatment unit includes a dehydration tower and a purification tower, wherein the dehydration tower is used for dehydrating olefins and the purification tower is used for purifying syngas. A slurry bed reactor, wherein the dehydration tower and the purification tower are respectively connected to the slurry bed reactor, and the slurry bed reactor is used to carry out a hydroformylation reaction; The catalyst regeneration unit includes an activation vessel and a ligand replenishment tank, which are respectively connected to the slurry bed reactor. The refining unit includes a flash distillation column and a distillation column, wherein the flash distillation column is connected to the slurry bed reactor and the distillation column is connected to the flash distillation column.

Images