Butyl octanol liquid phase aldehyde hydrogenation process

Abstract

The invention relates to the technical field of organic chemical industry, in particular to a butanol and octanol liquid-phase aldehyde hydrogenation process. The technical scheme adopted by the invention is as follows: the method comprises the following steps: a) production of octanol: conveying n-butyraldehyde into a condensation reactor under the reaction conditions that the temperature is 120 DEG C and the pressure is 0.5 MPa; the condensation reactor is in a kettle type homogeneous-phase stirring-free and jacket-free form; (condensation and dehydration reactions are carried out in the presence of dilute sodium hydroxide) reaction products are cooled and then fed into a separator, separated octenal enters an evaporator, and octenal becomes gas and then is mixed with hydrogen to obtain a raw material mixture; b) production of butanol: directly conveying n-butyraldehyde into a hydrogenation system.The process has the advantages of mild reaction conditions, high catalyst activity, long service life, high product purity and the like, and is simple in process step, easy to operate and control and suitable for large-scale industrial production.

Description

Technical Field

[0001] This invention relates to the field of organic chemical technology, and in particular to a liquid-phase hydrogenation process for butanol and octanol aldehydes. Background Technology

[0002] Butanol (butanol and octanol) is a crucial organic chemical raw material that plays an irreplaceable role in numerous fields. It is widely used in the production of plasticizers, significantly improving the flexibility and durability of plastics. In the solvent field, butanol serves as a highly efficient solvent, used in various industrial cleaning agents and coatings. Furthermore, it plays a vital role in the production of surfactants, contributing to improved detergency and foam stability.

[0003] The traditional process for producing butanol and octanol mainly employs the gas-phase aldehyde hydrogenation method. While this method is relatively simple in terms of equipment and easy to operate and implement, its drawbacks cannot be ignored. The high reaction temperature not only places high demands on the equipment but may also lead to side reactions, affecting product purity and yield. Furthermore, the catalyst is prone to deactivation under these conditions, requiring frequent replacement, which increases production costs and operational complexity. Summary of the Invention

[0004] The purpose of this invention is to provide a liquid-phase hydrogenation process for butanol and octanol, which has the advantages of mild reaction conditions, high catalyst activity, long catalyst life, and high product purity.

[0005] The technical solution of the present invention is as follows: A liquid-phase aldehyde hydrogenation process for butanol and octanol, characterized by the following steps: a) Octanol production: n-Butyraldehyde is fed into a condensation reactor under the following conditions: temperature 120°C, pressure 0.5 MPa; the condensation reactor is a homogeneous, stirred, and jacketed type; (the condensation and dehydration reaction are carried out in the presence of dilute sodium hydroxide). The reaction product is cooled and then fed into a separator. The separated octenal enters an evaporator, where it is mixed with hydrogen to obtain a raw material mixture; b) Butanol production: n-Butyraldehyde is directly fed into a hydrogenation system, and the raw material mixture is passed into a hydrogenation reactor containing a catalyst. Liquid-phase aldehyde hydrogenation is carried out under medium pressure to obtain crude butanol. The crude butanol and / or crude octanol are distilled to obtain high-purity butanol and octanol; the catalyst is a supported catalyst, the active components include nickel, copper and chromium, and the support is silicon dioxide; the composition of the catalyst is: 25% Cu, 5% Cr, and the balance is Ni; the reaction conditions are: temperature 80~150℃, pressure 0.4~4.0 MPaG, liquid hourly space velocity ≥0.1 h-1, n(H2) / n(liquid)=8:1, the catalyst is a black strip with a diameter of 1.5~5.0 mm and a length of 3.0~15.0 mm, the active component is Ni, the bulk density is 0.60~0.90 kg / L, and the specific surface area is ≥80 m2 / g.

[0006] Furthermore, regarding the production of butanol, the reaction conditions are: temperature 100℃, pressure 2.4MPaG, liquid hourly space velocity ≥0.1h-1, n(H2) / n(liquid) = 8:1.

[0007] The beneficial effects of this invention are: 1) Mild reaction conditions: This process has the advantages of mild reaction conditions, high catalyst activity, long lifespan, and high product purity.

[0008] 2) High catalyst activity and long lifespan: The supported catalyst used in this invention has high activity and long lifespan due to the synergistic effect of the active components nickel, copper and chromium.

[0009] 3) High product purity: After distillation, the obtained products, butanol and octanol, have high purity, meeting market demand.

[0010] 4) Simple process: The process steps provided by this invention are simple, easy to operate and control, and suitable for large-scale industrial production. Attached Figure Description

[0011] Figure 1 The process flow diagram of butanol liquid-phase aldehyde hydrogenation provided by this invention; In the diagram: 1. Aldehyde; 2. Condensation reactor; 3. Condenser; 4. Separator; 5. Water layer; 6. Hydrogen; 7. Hydrogenation reactor; 8. Crude butanol / octanol. Detailed Implementation

[0012] like Figure 1 As shown, a liquid-phase aldehyde hydrogenation process for butanol and octanol is characterized by the following steps: a) Regarding octanol production: n-Butyraldehyde is fed into a condensation reactor under the following conditions: temperature 120°C, pressure 0.5 MPa; the condensation reactor is a homogeneous, stirred, and jacketed type; (the condensation and dehydration reaction are carried out in the presence of dilute sodium hydroxide). The reaction product is cooled and then fed into a separator. The separated octenal enters an evaporator, where it is mixed with hydrogen to obtain a raw material mixture; b) Regarding butanol production: n-Butyraldehyde is directly fed into a hydrogenation system, and the raw material mixture is passed into a hydrogenation reactor containing a catalyst. Liquid-phase aldehyde hydrogenation is carried out under medium pressure to obtain crude butanol. The catalyst is a supported catalyst with active components including nickel, copper, and chromium, and the support is silicon dioxide. The catalyst composition is 25% Cu, 5% Cr, and the balance is Ni. The reaction conditions are: temperature 80~150℃, pressure 0.4~4.0MPaG, liquid hourly space velocity ≥0.1h-1, n(H2) / n(liquid)=8:1. The catalyst is a black strip with a diameter of 1.5~5.0mm and a length of 3.0~15.0mm. The active component is Ni, the bulk density is 0.60~0.90kg / L, and the specific surface area is ≥80m2 / g.

[0013] Regarding the production of butanol, the reaction conditions are: temperature 100℃, pressure 2.4MPaG, liquid hourly space velocity ≥0.1h-1, n(H2) / n(liquid) = 8:1.

[0014] Raw material preparation: Regarding octanol production: n-Butyraldehyde 1 enters condensation reactor 2. The reaction conditions are: temperature 120℃, pressure 0.5MPa. Condensation reactor 2 is a homogeneous, stirred, and jacketed type. The reaction proceeds with condensation and dehydration in the presence of dilute sodium hydroxide. The reaction product is cooled by condenser 3 and then sent to separator 4. The separated octenal enters evaporator, and the water layer 5 is directly discharged. Octenal, after becoming a gas in the evaporator, is mixed with hydrogen 6 to obtain the raw material mixture. The molar ratio of hydrogen should be higher than that of aldehydes to ensure complete hydrogenation. Regarding butanol production: n-Butyraldehyde directly enters the hydrogenation system.

[0015] Liquid-phase aldehyde hydrogenation reaction: The raw material mixture is fed into hydrogenation reactor 7, which contains a catalyst. Hydrogenation reactor 7 is a packed bed reactor, and the reaction conditions are: temperature 80~150℃, pressure 0.4~4.0MPaG, liquid hourly space velocity ≥0.1h-1, n(H2) / n(liquid)=8:1.

[0016] Crude alcohol distillation: The crude butanol / octanol 8 obtained from the reaction is subjected to distillation. During the distillation process, by controlling the temperature and pressure, light and heavy components are removed to obtain high-purity butanol and octanol.

[0017] Catalyst regeneration: After a period of use, the activity of the catalyst decreases due to the deposition of carbon and other residues on its surface, requiring regeneration and activation. Regeneration typically involves using high-temperature air and steam to oxidize and burn off impurities on the catalyst surface, followed by reduction with hydrogen. The regeneration time is 16–24 hours, the temperature is 200–350°C, and the pressure is 0.4 MPa.

[0018] The specific reaction steps are as follows: Step 1: Introduce the raw material mixture from the bottom of the reactor at a certain flow rate to ensure that the raw material is evenly distributed in the catalyst bed.

[0019] Step 2: Inside the reactor, the raw material mixture comes into full contact with the catalyst. Under the action of the catalyst, n-butyraldehyde and isobutyraldehyde undergo a hydrogenation reaction with hydrogen to produce butanol and octanol.

[0020] Step 3: During the reaction, control the reaction temperature and pressure to ensure the reaction proceeds under optimal conditions. Simultaneously, regularly monitor the reactor temperature and pressure and adjust them promptly to maintain stability.

[0021] Step 4: The reaction product flows out from the top of the reactor and enters the subsequent processing steps.

[0022] Crude alcohol distillation: Crude butanol and / or crude octanol are distilled to obtain high-purity butanol and octanol.

[0023] The catalyst used in the reaction was independently developed by the company and named the HK-1 hydrogenation catalyst. It is suitable for the deep hydrogenation of raw materials such as ketones, aldehydes, nitriles, nitro groups, petroleum resins, and aromatics. It features low reaction temperature, high selectivity, and high processing capacity, meeting the needs of high-quality fine chemical production and value-added processing. The overall performance of the catalyst has reached the international advanced level. The HK-1 hydrogenation catalyst uses a patented method to produce nano-scale nickel precursors. Through special molding and reduction passivation technologies, it is prepared into a series of products including powders, strips, and cylindrical strips, meeting different application scenarios such as slurry-bed hydrogenation and fixed-bed hydrogenation.

[0024] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements or substitutions without departing from the principles of the present invention, and these improvements or substitutions should also be considered within the scope of protection of the present invention.

Claims

1. A liquid-phase hydrogenation process for butanol and octanol, characterized in that, Includes the following steps: a) Regarding octanol production: n-Butyraldehyde is fed into a condensation reactor under the following conditions: temperature 120°C, pressure 0.5 MPa. The condensation reactor is a homogeneous, stirred, and jacketed type. (The condensation and dehydration reactions occur in the presence of dilute sodium hydroxide.) The reaction product is cooled and then fed into a separator. The separated octenal enters an evaporator, where it is converted into a gas and mixed with hydrogen to obtain a raw material mixture. b) Regarding butanol production: n-Butyraldehyde is directly fed into a hydrogenation system. The raw material mixture is passed into a hydrogenation reactor containing a catalyst, where a liquid-phase aldehyde hydrogenation reaction is carried out under medium pressure to obtain crude butanol and / or crude octanol. The crude butanol... The catalyst is subjected to distillation with / or crude octanol to obtain high-purity butanol and octanol; the catalyst is a supported catalyst, the active components include nickel, copper and chromium, and the support is silicon dioxide; the composition of the catalyst is: 25% Cu, 5% Cr, and the balance is Ni; the reaction conditions are: temperature 80~150℃, pressure 0.4~4.0 MPaG, liquid hourly space velocity ≥0.1 h-1, n(H2) / n(liquid)=8:1, the catalyst is a black strip with a diameter of 1.5~5.0 mm and a length of 3.0~15.0 mm, the active component is Ni, the bulk density is 0.60~0.90 kg / L, and the specific surface area is ≥80 m2 / g.

2. The butanol / octanol liquid-phase aldehyde hydrogenation process according to claim 1, characterized in that: Regarding the production of butanol, the reaction conditions are: temperature 100℃, pressure 2.4MPaG, liquid hourly space velocity ≥0.1h-1, n(H2) / n(liquid) = 8:1.

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