A catalyst for preparing butanol and octanol by hydrogenation of butyraldehyde and octenal and a preparation method thereof

Abstract

This invention provides a catalyst for the hydrogenation of butyraldehyde and octenal to prepare butanol and octanol, and a method for preparing the same. The catalyst comprises, by mass percentage, 15-35% CuO, 60-70% SiO2, 0.05-5% ZrO, and 0.001-0.25% Nb2O5. By introducing zirconium oxide and niobium pentoxide as synergistic agents on the basis of a copper-silicon catalyst, the catalyst lifetime is significantly improved.

Description

Technical Field

[0001] This invention relates to the field of catalyst technology, and in particular to a catalyst for the hydrogenation of butyraldehyde and octenal to prepare butanol and octanol, and a method for preparing the same. Background Technology

[0002] Butanol and octanol are important organic chemical raw materials. Butanol is mainly used to produce plasticizers for phthalates, aliphatic diesters and phosphate esters. It is widely used in various plastic and rubber products. It is a raw material for the production of butyraldehyde, butyric acid, butylamine, butyl acrylate, dibutyl sebacate and butyl lactate, etc. It is also an extractant for oils, drugs (such as antibiotics, hormones and vitamins) and fragrances, as well as an additive for alkyd resin coatings.

[0003] CN 104513134 A discloses a n-butanol composition obtained by the hydrogenation reaction of n-butyraldehyde. This patent uses a polymer-supported Raney Ni catalyst to obtain a n-butanol composition with a very low n-butyl ether content, which can reduce production energy consumption and improve product quality and yield.

[0004] CN 1251796 C discloses a catalyst for the hydrogenation of n-butyraldehyde to n-butanol and its preparation method, which is mainly used for the gas-phase hydrogenation of n-butyraldehyde to n-butanol and the preparation of corresponding alcohols from corresponding aldehydes.

[0005] Currently, the main industrial method for producing butanol and octanol is a low-pressure carbonyl synthesis process catalyzed by rhodium. Propylene reacts with syngas in the presence of a rhodium catalyst via carbonylation to produce butyraldehyde. The condensation of two butyraldehyde molecules yields octenal. Butyraldehyde or octenal is then hydrogenated in the presence of a hydrogenation catalyst to yield butanol or octanol, respectively. Both butyraldehyde and octenal contain a certain amount of butyric acid, which can easily damage the catalyst structure at the reaction temperature, leading to catalyst deactivation. Therefore, developing an acid-resistant aldehyde hydrogenation catalyst is of great significance for improving catalyst lifetime. Summary of the Invention

[0006] The purpose of this invention is to provide a catalyst and preparation method for the hydrogenation of butyraldehyde and octenal to prepare butanol and octanol. Based on the copper-silicon catalyst, zirconium oxide and niobium pentoxide are introduced as synergistic agents, which significantly improves the catalyst lifetime.

[0007] To achieve the above objectives, in a first aspect, this application provides a catalyst for the hydrogenation of butyraldehyde and octenaldehyde to prepare butanol and octanol, comprising, by mass percentage, 15-35% CuO, 60%-70% SiO2, 0.05-5% ZrO, and 0.001-0.25% Nb2O5.

[0008] Optionally, it may also include 0.01%-1% Ag.

[0009] To achieve the above objectives, in a second aspect, this application provides a method for preparing a catalyst for the hydrogenation of butyraldehyde and octenal to prepare butanol and octanol, comprising the following steps: S1. Prepare a copper ammonia solution by mixing copper nitrate and ammonia water; S2. Add the copper ammonia solution and ammonia water in parallel to the continuously stirred silica sol, and control the precipitation temperature and pH value. S3. Filter, wash, dry and calcine the precipitated slurry; S4. Prepare a mixed solution of zirconium nitrate and niobium oxalate, and impregnate the calcined catalyst in the mixed solution; S5. The impregnated catalyst is dried, calcined, and pressed into tablets.

[0010] Optionally, in step S4, the mixed solution further includes silver nitrate.

[0011] Optionally, in step S1, the copper-ammonia molar ratio is 0.15-0.25.

[0012] Optionally, in step S2, the pH value is controlled at 6.5-11 and the temperature is controlled at 20-70℃.

[0013] Optionally, the drying temperature is 80-180℃ and the calcination temperature is 350-650℃.

[0014] Optionally, the roasting temperature is 550-600℃.

[0015] Optionally, the molar ratio of zirconium nitrate to niobium oxalate is 40-60.

[0016] This invention provides a catalyst and its preparation method for the hydrogenation of butyraldehyde and octenal to butanol and octanol. Compared with existing technologies, its advantages are as follows: By adding ZrO and Nb2O5 as synergistic agents, both of which are amphoteric oxides, a Zr-Nb composite oxide is formed and uniformly loaded on the catalyst surface and pore inlets (the main reaction hotspot areas). The core acid resistance principle is physical barrier + chemical protection, which fundamentally avoids the contact reaction between organic acids and Cu active components. The Zr-Nb composite oxide forms a dense nanoscale protective fence around Cu nanoparticles, acting as a "physical barrier" between organic acid molecules and Cu active centers, significantly reducing the reaction of butyric acid and other organic acids. The diffusion and contact of organic acid molecules to Cu active centers reduces the probability of reaction at high temperatures. Zr-Nb composite oxides have weak chemisorption properties for organic acids such as butyric acid, which can preferentially adsorb organic acid molecules on the catalyst surface, avoiding adsorption and carbon deposition on the Cu active center surface. At the same time, the adsorbed organic acids will not react with Zr-Nb composite oxides and can be desorbed with the reaction gas flow without affecting the catalyst structure. There is a weak interaction between Zr-Nb composite oxides and Cu active centers, which can effectively fix Cu nanoparticles. Even if a small amount of organic acid breaks through the barrier and reacts with Cu, it can reduce the dissolution and agglomeration of Cu particles and delay the decline in catalytic activity. Attached Figure Description

[0017] Appendix Figure 1 This is a schematic diagram of the process flow of the present invention. Detailed Implementation

[0018] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

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

[0020] The present invention discloses a catalyst for the hydrogenation of butyraldehyde and octenaldehyde to prepare butanol and octanol, comprising, by mass percentage, 15-35% CuO, 60%-70% SiO2, 0.05-5% ZrO, 0.001-0.25% Nb2O5, and 0.01%-1% Ag.

[0021] Acid deactivation pain point: At the hot spot temperature of the reaction, Cu will react with organic acids such as butyric acid in the raw materials to form soluble copper organic acid salts. The part of Cu nanoparticles in contact with the support is most likely to react with organic acids, causing Cu active components to be dissolved and lost from the support surface. At the same time, the high temperature adsorption and carbon deposition of organic acids will cover the remaining Cu active centers, and the catalytic activity will decrease rapidly.

[0022] The two-step method of "preparing Cu-SiO2 host by co-precipitation of copper ammonia solution + introducing Zr-Nb-Ag by impregnation" is based on the core principle of achieving a precise structural design of "internal distribution of active centers + surface distribution of acid-resistant / auxiliary agents", which is highly compatible with the high-temperature deactivation mechanism of organic acids.

[0023] The first step, co-precipitation, involves the slow decomposition of copper-ammonia complexes, which allows CuO to be uniformly dispersed in the internal pores and shallow surface of the SiO2 support, rather than in the outermost layer of the catalyst. This spatially reduces the direct contact between the Cu active centers and organic acids.

[0024] The second step is impregnation: Zr-Nb-Ag is loaded around the Cu nanoparticles of the catalyst by impregnation, forming a dense "acid-resistant protective shell" that slows down the detachment of copper nanoparticles from the catalyst surface.

[0025] This structural design avoids the decrease in catalytic activity caused by acid-resistant additives covering the internal Cu active centers, while maximizing the physical barrier and chemical adsorption effects of Zr-Nb composite oxides. It solves the problem of Cu loss under high temperature from organic acids from two dimensions: spatial distribution and functional synergy.

[0026] Furthermore, Ag, in nanoparticle form, is co-distributed with Zr-Nb composite oxide on the catalyst surface. Its core role is to enhance Cu activity and resist coking through electronic effects. While it does not directly improve acid resistance, it can offset the slight inhibition of catalytic activity by acid-resistant promoters, ensuring hydrogenation efficiency in acidic environments. Electronic effects: Electron transfer occurs between Ag and Cu. Ag donates electrons to Cu, increasing Cu's electron cloud density and enhancing Cu's adsorption and activation capacity for butyraldehyde molecules, compensating for the slight impact of physical barriers from Zr-Nb composite oxide on mass transfer. Anti-coking: Ag can lower the activation energy of coking reactions of organic acids at high temperatures, reducing coking formation on the catalyst surface, preventing pore blockage, and ensuring efficient mass transfer of reactants. Stabilizing Cu valence state: Ag can inhibit Cu... 0 The oxidation of Cu²⁺ reduces the probability of Cu reacting with organic acids at high temperatures, further delaying the loss of Cu active components.

[0027] To further illustrate this invention, the following embodiments are provided.

[0028] Example 1 a. Weigh 91.1g of copper nitrate trihydrate and 178.6g of ammonia water (37%) to prepare 800ml of copper ammonia solution; b. Add the copper ammonia solution and ammonia water (37%) in parallel to 98.54g of silica sol (30%) under constant stirring. The precipitation temperature is 40℃, and the precipitation pH is 7.0; c. Filter, wash, dry at 120℃, and calcine at 580℃ for the precipitate; d. Weigh 3.44g of zirconium nitrate pentahydrate and 0.081g of niobium oxalate to prepare 100ml of aqueous solution, and impregnate the calcined catalyst in... In the aqueous solution; e. The impregnated catalyst is dried at 120℃, calcined at 580℃, and pressed into tablets; f. 20g of the catalyst formed in step e is loaded into a fixed-bed reactor with an inner diameter of 20mm, the temperature is first raised to 170℃ in a N2 environment, and then raised to 200℃ at a heating rate of 1℃ / min in a mixed atmosphere of hydrogen and nitrogen, and then held at the temperature for 3h; g. The reduced catalyst is subjected to butyraldehyde (containing 1% butyric acid) hydrogenation reaction at 145℃, 0.6MPa, and space velocity of 0.2.

[0029] Example 2 a. Weigh 91.1g of copper nitrate trihydrate and 178.6g of ammonia water (37%) to prepare an 800ml copper ammonia solution; b. Add the copper ammonia solution and ammonia water (37%) concurrently to 99.27g of silica sol (30%) under constant stirring. The precipitation temperature is 40℃, and the precipitation pH is 7.0; c. Filter, wash, dry at 120℃, and calcine at 580℃ for the precipitate slurry; d. Weigh 1.72g of zirconium nitrate pentahydrate and 0.04g of niobium oxalate to prepare a 100ml aqueous solution, and impregnate the calcined catalyst with the solution. e. The impregnated catalyst is dried at 120°C, calcined at 580°C, and pressed into tablets; f. 20g of the catalyst formed in step e is loaded into a fixed-bed reactor with an inner diameter of 20mm. The temperature is first raised to 170°C in a N2 environment, and then raised to 200°C at a heating rate of 1°C / min in a mixed atmosphere of hydrogen and nitrogen, and then held at the temperature for 3h; g. The reduced catalyst is subjected to butyraldehyde (containing 1% butyric acid) hydrogenation reaction at 145°C, 0.6MPa, and space velocity of 0.2.

[0030] Example 3 a. Weigh 91.1g of copper nitrate trihydrate and 178.6g of ammonia water (37%) to prepare 800ml of copper ammonia solution; b. Add the copper ammonia solution and ammonia water (37%) concurrently to 98.51g of silica sol (30%) under constant stirring. The precipitation temperature is 40℃, and the precipitation pH is 7.0; c. Filter, wash, dry at 120℃, and calcine at 580℃ for the precipitate slurry; d. Weigh 3.44g of zirconium nitrate pentahydrate and 0.162g of niobium oxalate to prepare 100ml of aqueous solution, and impregnate the calcined catalyst with the solution. e. The impregnated catalyst is dried at 120°C, calcined at 580°C, and pressed into tablets; f. 20g of the catalyst formed in step e is loaded into a fixed-bed reactor with an inner diameter of 20mm. The temperature is first raised to 170°C in a N2 environment, and then raised to 200°C at a heating rate of 1°C / min in a mixed atmosphere of hydrogen and nitrogen, and then held at the temperature for 3h; g. The reduced catalyst is subjected to butyraldehyde (containing 1% butyric acid) hydrogenation reaction at 145°C, 0.6MPa, and space velocity of 0.2.

[0031] Example 4 a. Weigh 91.1g of copper nitrate trihydrate and 178.6g of ammonia water (37%) to prepare 800ml of copper ammonia solution; b. Add the copper ammonia solution and ammonia water (37%) concurrently to 98.56g of silica sol (30%) under constant stirring. The precipitation temperature is 40℃, and the precipitation pH is 7.0; c. Filter, wash, dry at 120℃, and calcine at 580℃ for the precipitate slurry; d. Weigh 3.44g of zirconium nitrate pentahydrate and 0.04g of niobium oxalate to prepare 100ml of aqueous solution, and impregnate the calcined catalyst with the solution. e. The impregnated catalyst is dried at 120°C, calcined at 580°C, and pressed into tablets; f. 20g of the catalyst formed in step e is loaded into a fixed-bed reactor with an inner diameter of 20mm. The temperature is first raised to 170°C in a N2 environment, and then raised to 200°C at a heating rate of 1°C / min in a mixed atmosphere of hydrogen and nitrogen, and then held at the temperature for 3h; g. The reduced catalyst is subjected to butyraldehyde (containing 1% butyric acid) hydrogenation reaction at 145°C, 0.6MPa, and space velocity of 0.2.

[0032] Example 5 a. Weigh 91.1g of copper nitrate trihydrate and 178.6g of ammonia water (37%) to prepare an 800ml copper ammonia solution; b. Add the copper ammonia solution and ammonia water (37%) concurrently to 97.84g of silica sol (30%) under constant stirring. The precipitation temperature is 40℃, and the precipitation pH is 7.0; c. Filter, wash, dry at 120℃, and calcine at 580℃ for the precipitate slurry; d. Weigh 5.16g of zirconium nitrate pentahydrate and 0.081g of niobium oxalate to prepare a 100ml aqueous solution, and impregnate the calcined catalyst with the solution. e. The impregnated catalyst is dried at 120°C, calcined at 580°C, and pressed into tablets; f. 20g of the catalyst formed in step e is loaded into a fixed-bed reactor with an inner diameter of 20mm. The temperature is first raised to 170°C in a N2 environment, and then raised to 200°C at a heating rate of 1°C / min in a mixed atmosphere of hydrogen and nitrogen, and then held at the temperature for 3h; g. The reduced catalyst is subjected to butyraldehyde (containing 1% butyric acid) hydrogenation reaction at 145°C, 0.6MPa, and space velocity of 0.2.

[0033] Example 6 a. Weigh 91.1g of copper nitrate trihydrate and 178.6g of ammonia water (37%) to prepare 800ml of copper ammonia solution; b. Add the copper ammonia solution and ammonia water (37%) concurrently to 98.97g of silica sol (30%) under constant stirring. The precipitation temperature is 40℃, and the precipitation pH is 7.0; c. Filter, wash, dry at 120℃, and calcine at 580℃ for the precipitate slurry; d. Weigh 2.41g of zirconium nitrate pentahydrate and 0.081g of niobium oxalate to prepare 100ml of aqueous solution, and impregnate the calcined catalyst with the solution. e. The impregnated catalyst is dried at 120°C, calcined at 580°C, and pressed into tablets; f. 20g of the catalyst formed in step e is loaded into a fixed-bed reactor with an inner diameter of 20mm. The temperature is first raised to 170°C in a N2 environment, and then raised to 200°C at a heating rate of 1°C / min in a mixed atmosphere of hydrogen and nitrogen, and then held at the temperature for 3h; g. The reduced catalyst is subjected to butyraldehyde (containing 1% butyric acid) hydrogenation reaction at 145°C, 0.6MPa, and space velocity of 0.2.

[0034] Example 7 a. Weigh 91.1g of copper nitrate trihydrate and 178.6g of ammonia water (37%) to prepare 800ml of copper ammonia solution; b. Add the copper ammonia solution and ammonia water (37%) concurrently to 99.97g of silica sol (30%) under constant stirring. The precipitation temperature is 40℃, and the precipitation pH is 7.0; c. Filter, wash, dry at 120℃, and calcine at 580℃ for the precipitate slurry; d. Weigh 0.081g of niobium oxalate to prepare 100ml of aqueous solution, and impregnate the calcined catalyst in this aqueous solution. e. The impregnated catalyst is dried at 120℃, calcined at 580℃, and pressed into tablets; f. 20g of the catalyst formed in step e is loaded into a fixed-bed reactor with an inner diameter of 20mm. The temperature is first raised to 170℃ in a N2 environment, and then raised to 200℃ at a heating rate of 1℃ / min in a mixed atmosphere of hydrogen and nitrogen, and then held at the temperature for 3h; g. The reduced catalyst is subjected to butyraldehyde (containing 1% butyric acid) hydrogenation reaction at 145℃, 0.6MPa, and space velocity of 0.2.

[0035] Example 8 a. Weigh 91.1g of copper nitrate trihydrate and 178.6g of ammonia water (37%) to prepare 800ml of copper ammonia solution; b. Add the copper ammonia solution and ammonia water (37%) concurrently to 98.57g of silica sol (30%) under constant stirring. The precipitation temperature is 40℃, and the precipitation pH is 7.0; c. Filter, wash, dry at 120℃, and calcine at 580℃ for the precipitate slurry; d. Weigh 3.44g of zirconium nitrate pentahydrate to prepare 100ml of aqueous solution, and impregnate the calcined catalyst in this aqueous solution. e. The impregnated catalyst is dried at 120℃, calcined at 580℃, and pressed into tablets; f. 20g of the catalyst formed in step e is loaded into a fixed-bed reactor with an inner diameter of 20mm. The temperature is first raised to 170℃ in a N2 environment, and then raised to 200℃ at a heating rate of 1℃ / min in a mixed atmosphere of hydrogen and nitrogen, and then held at the temperature for 3h; g. The reduced catalyst is subjected to butyraldehyde (containing 1% butyric acid) hydrogenation reaction at 145℃, 0.6MPa, and space velocity of 0.2.

[0036] Reference Examples 20g of purchased butyraldehyde hydrogenation catalyst was loaded into a fixed-bed reactor with an inner diameter of 20mm. The temperature was first raised to 170℃ in a N2 environment, and then raised to 200℃ in a mixed atmosphere of hydrogen and nitrogen at a heating rate of 1℃ / min and held at that temperature for 3h. The reduced catalyst was then subjected to butyraldehyde (containing 1% butyric acid) hydrogenation reaction at 145℃, 0.6MPa and space velocity of 0.2. The table above shows that the catalyst prepared by this invention still has a longer lifespan than ordinary copper-based catalysts when the butyraldehyde raw material contains a high concentration of organic acids. The structure of the catalyst is not destroyed by the organic acids, and there is a good synergistic effect among the components of the catalyst. It is an excellent acid-resistant catalyst.

[0037] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A catalyst for the hydrogenation of butyraldehyde and octenal to prepare butanol and octanol, characterized in that, It includes 15-35% CuO, 60-70% SiO2, 0.05-5% ZrO, and 0.001-0.25% Nb2O5 by mass percentage.

2. The catalyst for the hydrogenation of butyraldehyde and octenal to prepare butanol and octanol as described in claim 1, characterized in that: It also includes 0.01%-1% Ag.

3. A method for preparing a catalyst for the hydrogenation of butyraldehyde and octenal to prepare butanol and octanol, characterized in that: Includes the following steps: S1. Prepare a copper ammonia solution by mixing copper nitrate and ammonia water; S2. Add the copper ammonia solution and ammonia water in parallel to the continuously stirred silica sol, and control the precipitation temperature and pH value. S3. Filter, wash, dry and calcine the precipitated slurry; S4. Prepare a mixed solution of zirconium nitrate and niobium oxalate, and impregnate the calcined catalyst in the mixed solution; S5. The impregnated catalyst is dried, calcined, and pressed into tablets.

4. The method for preparing a catalyst for the hydrogenation of butyraldehyde and octenal to butanol and octanol as described in claim 3, characterized in that: In step S4, the mixed solution also includes silver nitrate.

5. The method for preparing a catalyst for the hydrogenation of butyraldehyde and octenal to butanol and octanol as described in claim 3, characterized in that: In step S1, the copper-ammonia molar ratio is 0.15-0.

25.

6. The method for preparing a catalyst for the hydrogenation of butyraldehyde and octenal to butanol and octanol as described in claim 3, characterized in that: In step S2, the pH value is controlled at 6.5-11 and the temperature is controlled at 20-70℃.

7. The method for preparing a catalyst for the hydrogenation of butyraldehyde and octenal to butanol and octanol as described in claim 3, characterized in that: The drying temperature is 80-180℃, and the calcination temperature is 350-650℃.

8. The method for preparing a catalyst for the hydrogenation of butyraldehyde and octenal to butanol and octanol as described in claim 7, characterized in that: The roasting temperature is 550-600℃.

9. The method for preparing a catalyst for the hydrogenation of butyraldehyde and octenal to butanol and octanol as described in claim 3, characterized in that: The molar ratio of zirconium nitrate to niobium oxalate is 40-60.

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