A one-step process for the preparation of normal aldehydes

Abstract

The application provides a method for preparing normal aldehyde by one-step method, in which a raw material non-conjugated allyl alcohol is contacted with a catalyst under the condition of 0-2.0 bar in a hydrogen atmosphere containing carbon monoxide, and a normal aldehyde is generated by reaction; wherein the catalyst is a supported catalyst, including an active component main metal and an active assistant; the active component main metal includes at least one of rhodium, ruthenium and platinum elements, and the active assistant includes at least one of sulfur, selenium, tellurium, phosphorus, arsenic, antimony, bismuth, tin, cadmium, cerium and praseodymium elements. By controlling the synergistic effect of the reaction condition and the catalyst component, the double bond migration and saturated hydrogenation in the raw material are jointly regulated, the raw material conversion rate and the selectivity of the normal aldehyde are improved, and the generation of by-products is significantly reduced. The process flow of the application is simple and efficient, and is beneficial to large-scale production and application.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of chemical synthesis, in particular to a method for preparing normal aldehyde by one-step method. BACKGROUND

[0002] Normal aldehyde, also known as straight-chain aldehyde or aliphatic aldehyde, is a kind of organic compound in which the aldehyde group (i.e. -CHO group) is directly connected to a straight-chain hydrocarbon group. Normal aldehyde is an important raw material or intermediate for many organic synthesis reactions, and through oxidation, reduction, condensation and other reactions, other important organic compounds such as alcohol, acid and ester can be prepared; in addition, normal aldehyde is an important intermediate for manufacturing perfumes, seasonings, plastics, rubbers, coatings and the like, and some normal aldehyde with bactericidal and preservative properties is also used to manufacture disinfectants, preservatives and the like. The wide application of normal aldehyde products in industrial production puts forward new requirements for the production volume of n-octyl aldehyde and the convenience of process flow.

[0003] The current disclosed production method of normal octyl aldehyde (taking n-octyl aldehyde as an example) includes normal octyl alcohol catalytic oxidation method, 1-heptene hydroformylation method and 7-octene-1-al hydrogenation method. Patent EP0069339B1 and US4510331 respectively propose a method for producing 7-octene-1-al and its derivatives, which includes isomerizing 2,7-octadiene-1-ol in the presence of a catalyst containing oxides of at least two metals selected from copper, chromium and zinc, and a method for producing 7-octyne-1-al derivatives, which has the following problems:

[0004] 1) the 7-octene-1-al hydrogenation method based on the method to prepare normal aldehyde, at least including ① isomerization 2,7-octadiene-1-ol, and ② 7-octene-1-al hydrogenation to prepare normal aldehyde, both of which may produce a large amount of by-products in the two-step organic synthesis reaction process, and need to be combined with the corresponding rectification purification process, so the preparation process flow is complex, and is not suitable for large-scale industrial production; 2) the 7-octene-1-al used in the patent is prepared by isomerization of 2,7-octadiene-1-ol at 200-250 DEG C under the catalysis of copper-chromium catalyst, a large amount of by-products will be generated in the reaction process, and these by-products will form a variety of by-products and high-boiling-point products with molecular structure and boiling point extremely close to 7-octene-1-al at high temperature, which will increase the difficulty of subsequent product separation and separation cost; 3) in the process of preparing 7-octene-1-al by isomerization of 2,7-octadiene-1-ol by the copper-chromium catalyst, the catalytic activity of the catalyst will gradually decrease, thereby causing the selectivity of 7-octene-1-al to decrease, the proportion of high-boiling-point products to increase, and the product purity and product separation process difficulty of the subsequent hydrogenation reaction to be affected; in addition, 4) after hydrogenation of 7-octene-1-al, the proportion of n-octanal / n-octanol in the obtained product is 69:31-72:26, and the relatively high proportion of n-octanol is not conducive to reducing the process production cost.

[0005] In order to overcome the limitations of the prior art normal aldehyde preparation method, the following problems need to be solved: ① developing a normal aldehyde production process and supporting catalyst technology from the perspective of acceptable industrialization cost, achieving high reaction yield; ② realizing various regulation mechanisms through process condition control and catalyst optimization, maximizing the synergistic effect to improve the selectivity of the product, and minimizing the occurrence of side reactions, thereby further reducing the difficulty of subsequent reaction product separation; ③ maintaining the catalytic activity of the catalyst for a long time, prolonging the service life of the catalyst, and reducing the use cost of the catalyst; ④ optimizing the process flow, improving the production efficiency, and maximizing the technical competitiveness. SUMMARY

[0006] In view of the deficiencies in the prior art, the present application discloses a method for preparing normal aldehyde from conjugated allyl alcohol raw material by one-step method, which has high product yield and product selectivity, simple and efficient process flow, and is beneficial to large-scale production and application.

[0007] In order to achieve the above technical purposes, on the one hand, the present application proposes a one-step method for preparing normal aldehyde, in which the raw material non-conjugated allyl alcohol is contacted with a catalyst in a hydrogen atmosphere containing carbon monoxide under the condition of 0-2.0 bar, and normal aldehyde is generated by reaction;

[0008] The catalyst is a supported catalyst, and includes an active component main metal and an active assistant; the active component main metal includes at least one of rhodium, ruthenium and platinum elements, and the active assistant includes at least one of sulfur, selenium, tellurium, phosphorus, arsenic, antimony, bismuth, tin and cerium elements.

[0009] In the above technical solution, the multiple technical features are cooperated to directly prepare the normal aldehyde with high purity in one step, and the reaction product contains only a small amount of normal alcohol saturated hydrogenation by-product and almost no double bond migration by-product. Specifically:

[0010] The active component main metal of the catalyst can be selected from at least one of rhodium, ruthenium and platinum elements, and the active assistant is used to synergistically catalyze the isomerization hydrogenation reaction of the non-conjugated allyl alcohol, so as to reduce the saturated hydrogenation activity and double bond migration activity of the main metal, control the active component to preferentially promote the isomerization of the allyl alcohol group in the raw material and inhibit the migration of the double bond to other positions and the saturated hydrogenation of the double bond, and finally avoid the generation of a series of by-products with similar structures and similar boiling points in the process of continuous dehydrogenation and hydrogenation when the copper-chromium catalyst is used to catalyze the reaction in the prior art. On this basis, the reaction is carried out in a hydrogen atmosphere containing carbon monoxide, the combination and separation of carbon monoxide and the active main metal in the catalyst, and the combination of the active assistant are used to comprehensively control or inhibit the hydrogenation and double bond migration activity of the active component main metal of the catalyst, so as to promote the reaction to proceed in the direction of normal aldehyde. Further, the reaction pressure for preparing the normal aldehyde in one step is controlled, and the isomerization hydrogenation reaction is carried out under a pressure of 0-2.0 bar, so as to not only inhibit the generation of saturated hydrogenation by-products, but also promote the timely desorption of carbon monoxide under low pressure to release the catalytic activity of the catalyst, promote the isomerization hydrogenation of the reaction raw material to obtain normal aldehyde.

[0011] The above technical solution combines multiple technical features for controlling the hydrogenation and double bond migration activity of the active component main metal to realize one-step synthesis of normal aldehyde. The material after the reaction can be directly purified by rectification to obtain normal aldehyde products with high yield and high purity. The examples and comparative examples of the present application show the experimental results of the synergistic control of multiple technical features for one-step preparation of normal aldehyde.

[0012] The process flow of the above technical solution is very simple, which is very beneficial to reduce the rectification and purification operation and energy consumption, optimize the production process and improve the production technology.

[0013] In a further example of the present application, the types of the active assistant in the catalyst are explored and optimized. Optionally, the active assistant includes at least one of sulfur, selenium, tellurium, phosphorus, bismuth, tin and cerium elements, which can be combined with the active component main metal to obtain better raw material conversion rate and normal aldehyde selectivity.

[0014] In further examples of the present application, the type of catalyst carrier is optimized, which can be at least one of alumina, activated carbon, silicon oxide, titanium oxide, zirconium oxide, molecular sieve, hydrotalcite, kaolin, and further can be one of silicon oxide, titanium oxide and zirconium oxide.

[0015] In further examples of the present application, the particle size of the active component main metal in the catalyst is optimized, which can be 1-100 nm, preferably 2-50 nm, and further preferably 5-30 nm.

[0016] In further examples of the present application, the ratio of the active component main metal to the carrier in the catalyst is optimized, which can be (0.001-0.05):1 in mass ratio. In further examples of the present application, the ratio of the active assistant to the carrier in the catalyst is optimized, which can be (0.001-0.02):1 in mass ratio. The active component main metal and the active assistant in the catalyst of the present application are both added in small amounts, but have high catalytic activity, can realize long-period continuous stable operation, and have a catalytic life of more than 1000 h, thereby greatly reducing the use cost of the catalyst and improving the technical competitiveness, which is very advantageous for controlling the industrialization cost in large-scale production.

[0017] In further examples of the present application, the amount of raw material non-conjugated allyl alcohol and catalyst in the process is explored, which can be 0.1-20 g / g / h, and further can be 0.5-10 g / g / h in mass hourly space velocity.

[0018] In further examples of the present application, the preparation method of the catalyst is explored and optimized. Optionally, the preparation steps of the catalyst include: after impregnation adsorption of active auxiliary soluble salt, first calcination, and impregnation adsorption of active component main metal soluble salt, the catalyst carrier is subjected to secondary calcination at a temperature of 120-200°C; and after completion of the calcination, reduction is performed in a hydrogen-containing atmosphere to obtain the catalyst. Based on a large number of exploration experiments, the research and development team of the present application found that the control of the calcination and reduction activation temperature in the preparation process of the catalyst can affect the product selectivity of the prepared catalyst in the catalytic reaction. Specifically, when the catalyst carrier loaded with the active auxiliary and the active component main metal is calcined and reduced and activated under high temperature conditions (generally, the calcination temperature is 400-600°C) according to the conventional supported catalyst, the active component main metal in the prepared catalyst has a strong adsorption capacity for unsaturated compounds and hydrogen, resulting in a high saturated hydrogenation capacity and double bond migration capacity, so that there is a high content of double bond migration by-products and n-alkanol saturated hydrogenation products in the product, thereby greatly reducing the n-aldehyde selectivity and yield; when the catalyst carrier loaded with the active auxiliary and the active component main metal is calcined and reduced and activated under lower temperature conditions (less than 200°C) in the preparation process of the catalyst, an unexpected effect is achieved: the lower calcination and reduction activation temperature makes the hydrogenation and double bond migration activity of the active component main metal of the catalyst remain at a relatively low level, which, in combination with the electronic modifier and synergistic catalysis of the active auxiliary contained in the catalyst, inhibits the double bond migration and saturated hydrogenation of the raw material, thereby controlling the preferential conversion of the raw material to n-aldehyde and reducing the occurrence of by-products such as n-alkanol.

[0019] It should be noted that the control conditions of the impregnation adsorption and first calcination of the active auxiliary in the present application are not limited, and those skilled in the art can select a suitable active auxiliary soluble salt to impregnate the carrier and perform calcination activation at a suitable temperature, so that the technical solutions formed are within the protection scope of the present application. In an optional example of the present application, the impregnation adsorption and calcination operation of the active auxiliary soluble salt includes: (i) dissolving the active auxiliary soluble salt in pure water, and optionally increasing the temperature of the solution to 30-100°C; (ii) impregnating and adsorbing the catalyst carrier in the solution of the active auxiliary soluble salt, and the impregnation adsorption time is optionally 0.5-24h; (iii) after washing the catalyst carrier adsorbed with the active auxiliary soluble salt with pure water for 3 times, calcining at 300-500°C in air, and the calcination time is optionally 0.5-5h.

[0020] It should be noted that the present application does not limit the specific operation of impregnating and adsorbing the active component main metal soluble salt into the catalyst carrier, and those skilled in the art can select a suitable active component main metal soluble salt to impregnate and adsorb the carrier according to the needs, and the technical solutions formed thereby are within the scope of the present application. In an optional example of the present application, the operation of impregnating and adsorbing the active component main metal soluble salt into the catalyst carrier comprises: (iv) preparing an aqueous solution of the active component main metal soluble salt, and optionally heating the aqueous solution to 30-100°C; (v) impregnating and adsorbing the catalyst carrier on which the active component soluble salt has been impregnated and adsorbed and calcined into the active component main metal soluble salt solution, and optionally adsorbing and impregnating for 0.5-24h.

[0021] It should be noted that the present application does not limit the time of the secondary calcination in the above-mentioned catalyst preparation process, which can be optionally 24-48h; the present application does not limit the time of the low-temperature reduction activation in the above-mentioned catalyst preparation process, which can be optionally 12-24h, and those skilled in the art can select a suitable low-temperature calcination and low-temperature reduction time according to the actual needs, and the technical solutions formed thereby are within the scope of the present application.

[0022] It should be noted that the present application does not limit the hydrogen-containing atmosphere in the reduction activation in the above-mentioned catalyst preparation process, which can be optionally a pure hydrogen atmosphere or a hydrogen atmosphere containing an inert gas, such as a hydrogen / nitrogen atmosphere, and those skilled in the art can select a suitable reduction atmosphere in the actual preparation process, and the technical solutions formed thereby are within the scope of the present application.

[0023] In further examples of the present application, the amount of hydrogen and the content of carbon monoxide in the hydrogen atmosphere containing carbon monoxide are explored. Optionally, in the hydrogen atmosphere containing carbon monoxide, the molar ratio of hydrogen to raw material is 1.1-10:1, preferably 1.5-5:1. Optionally, in the hydrogen atmosphere containing carbon monoxide, the molar ratio of carbon monoxide to hydrogen is 0.00001-0.01:1, preferably 0.00005-0.001:1, so as to prevent excessive addition of carbon monoxide from poisoning the catalyst or from hydrogen formylation with the raw material to reduce the selectivity of normal aldehydes, and also to prevent the occurrence of the case of affecting the service life of the catalyst due to chronic poisoning of the main metal of the active component of the catalyst.

[0024] In further examples of the present application, the reaction conditions are optimized, and optionally, the reaction is carried out in a hydrogen atmosphere containing carbon monoxide at 0.1-1 bar; optionally, the reaction temperature is 50-150°C, preferably 60-100°C.

[0025] The method for preparing normal aldehydes by continuous reaction has wide applicability and can be used for preparing normal aldehydes with different carbon atom numbers. In further examples of the present application, the non-conjugated allyl alcohol can be an allyl alcohol compound with a carbon-carbon double bond alkenyl group at the other end of the molecule; further, the non-conjugated allyl alcohol has 6-12 carbon atoms; in some optional examples of the present application, the non-conjugated allyl alcohol includes at least one of 2,5-hexadiene-1-ol, 2,6-heptadiene-1-ol, 2,7-octadiene-1-ol, 2,8-nonadiene-1-ol, 2,9-decadiene-1-ol, 2,10-undecadiene-1-ol, and 2,11-dodecadiene-1-ol. In the embodiments, the preparation of corresponding normal aldehydes from different non-conjugated allyl alcohol raw materials is shown.

[0026] It should be noted that the reaction of the present application can be carried out by batch method or continuous method, and further, the continuous method is optional. Those skilled in the art can select the appropriate operation mode according to the actual working conditions, and thus the technical solutions formed are within the protection scope of the present application.

[0027] It should be noted that the technical solution of the present application is not limited to the equipment used, and at least one of a loop reactor, a fixed bed reactor, a reaction kettle or a fluidized bed reactor can be selected, and further, the loop reactor or the fixed bed reactor is optional. Those skilled in the art can select the appropriate equipment through non-creative labor, and thus the technical solutions formed are within the protection scope of the present application.

[0028] Compared with the prior art, the present application has the following beneficial effects: under the conditions of hydrogen atmosphere containing carbon monoxide and low pressure, the catalyst containing active component main metal and active promoter is used to catalyze the one-step reaction of the non-conjugated allyl alcohol raw material to generate normal aldehyde. By controlling the reaction conditions and the synergistic effect of the catalyst components, the raw material conversion rate and the selectivity of normal aldehyde are improved, and the generation of by-products is significantly reduced. The preparation method of the one-step method not only greatly shortens the process flow, but also realizes continuous reaction, greatly reduces the difficulty and energy consumption of subsequent product separation, and further reduces the production cost, which is conducive to large-scale production and application. BRIEF DESCRIPTION OF DRAWINGS

[0029] The drawings accompanying the specification of this application are used to provide further understanding of the present application, and the illustrative embodiments of the present application and their descriptions are used to explain the present application, and do not constitute an improper limitation on the present application. In the drawings:

[0030] Figure 1 The process structure diagram of the preparation method of the present application is shown;

[0031] Figure 2 The transmission electron microscope (TEM) photo of the catalyst A after reduction at 120°C for 10h under hydrogen atmosphere is shown;

[0032] Figure 3 Figure 6 shows a transmission electron microscope (TEM) image of catalyst G after reduction under hydrogen atmosphere at 120°C for 10h. DETAILED DESCRIPTION

[0033] In order to facilitate the understanding of the present application, a more comprehensive description of the present application will be given below, and the preferred embodiments of the present application will be given. It should be understood that these embodiments are only used for more detailed description, and should not be understood as limiting the present application in any form, i.e. not intended to limit the protection scope of the present application.

[0034] Unless otherwise defined, the technical terms used in the following examples have the same meanings as generally understood by those skilled in the art to which the present application belongs. The test reagents used in the following examples, unless otherwise specified, are conventional biochemical reagents; and the experimental methods, unless otherwise specified, are conventional methods.

[0035] It should be noted that in the description of the present application, although the steps of the preparation method of the present application are described in a specific order in the present application, these orders are not limiting, and those skilled in the art can perform the steps in different orders without deviating from the basic principles of the present application.

[0036] In the following examples, gas chromatography is used for analysis of each component in the reaction system, and quantitative correction normalization method is used for quantification, which can be carried out according to the prior art, and on this basis, the conversion rate of reactants, the selectivity and yield of products are calculated. The gas chromatography analysis conditions are as follows:

[0037] Chromatographic column: Agilent DB-Wax (specification: 30m x 0.32mm x 0.25mm); injection port temperature: 300°C; split ratio: 30:1; column flow rate: 1.5mL / min; column temperature: 100°C for 0.5min; temperature rising program: 15°C / min to 300°C, holding for 8min; detector temperature: 300°C, hydrogen flow rate: 35mL / min, air flow rate: 350mL / min.

[0038] Catalyst preparation example 1: preparation of catalyst A (1% Rh-0.2% Se / SiO2)

[0039] SeO2 0.28 g was dissolved in 50 mL of pure water, and the temperature was raised to 35°C. 100 g of SiO2 carrier (20-40 mesh) was added, and impregnation adsorption was carried out for 24 h. After washing with pure water three times, the carrier was calcined at 400°C for 4 h. Rh nitrate (Rh content: 1 g) 2.8 g was dissolved in 100 mL of pure water, and the temperature was raised to 35°C. The calcined Se-SiO2 carrier was again impregnated and adsorbed for 3 h, and washed with pure water three times. The carrier was calcined at 150°C for 48 h. The obtained catalyst was reduced at 120°C for 10 h under a hydrogen atmosphere to obtain catalyst A.

[0040] Figure 1 Figure 2 Figure 2

[0041] Catalyst Preparation Examples 2-6: Catalysts B-F were prepared, and the specific preparation parameters and control conditions are shown in Table 1.

[0042] Table 1

[0043]

[0044] Catalyst Comparative Preparation Example 1: Catalyst G (1% Rh / SiO2) containing only an active main metal was prepared.

[0045] Rh nitrate (Rh content: 1 g) 2.8 g was dissolved in 100 mL of pure water, and the temperature was raised to 35°C. 100 g of SiO2 carrier (20-40 mesh) was added, and impregnation adsorption was carried out for 3 h. After washing with pure water three times, the carrier was calcined at 150°C for 48 h. The obtained catalyst was reduced at 120°C for 10 h under a hydrogen atmosphere to obtain catalyst G.

[0046] Figure 5 Figure 3 Figure 6

[0047] Catalyst Comparative Preparation Example 2: Catalyst H (0.2% Se / SiO2) containing only an active promoter was prepared.

[0048] SeO2 0.28 g was dissolved in 50 mL of pure water, and the temperature was raised to 35°C. 100 g of SiO2 carrier (20-40 mesh) was added, and impregnation adsorption was carried out for 24 h. After washing with pure water three times, the carrier was calcined at 400°C for 4 h. The obtained catalyst was reduced at 120°C for 10 h under a hydrogen atmosphere to obtain catalyst H.

[0049] Catalyst Comparative Preparation Example 3: Preparation of Catalyst I (1% Rh-0.2% Se / SiO2) - High Temperature Calcination

[0050] Dissolve 0.28 g of SeO2 in 50 mL of purified water, and heat to 35°C. Add 100 g of SiO2 carrier (20-40 mesh) to the solution, and immerse and adsorb for 24 h. After washing with purified water three times, calcine at 400°C for 4 h. Dissolve 2.8 g of rhodium nitrate (rhodium content: 1 g) in 100 mL of purified water, and heat to 35°C. Immerse and adsorb the calcined Se-SiO2 carrier again at 35°C for 3 h. After washing with purified water three times, calcine at 450°C for 48 h. Reduce the calcined catalyst at 120°C under a hydrogen atmosphere for 10 h to obtain Catalyst I.

[0051] Example 1

[0052] A one-step method for preparing n-aldehydes, as shown in Figure 1 The method comprises filling Catalyst A into a fixed bed reactor equipped with a heating and insulation device, the reactor has a tube diameter of 20 mm, a tube length of 1000 mm, and a catalyst filling height of 150 mm. Before the reaction, the reactor is purged with nitrogen three times. After the reaction starts, hydrogen with carbon monoxide (molar ratio of carbon monoxide to hydrogen: 0.0005:1) introduced in advance is introduced from the top of the reactor by a gas flow meter, and the raw material 2,7-octadiene-1-ol is pumped into a preheater by a plunger pump through a pipeline with heating, and the preheating temperature is 100°C. Then the material and hydrogen are mixed and introduced into the fixed bed reactor from the top of the reactor in a co-current manner. The hydrogen flow rate is controlled so that the molar ratio of the raw material 2,7-octadiene-1-ol to hydrogen is 1:1.8, the reaction bed temperature is controlled at 100°C, the system pressure is controlled at 0.9 bar, and the residence time is controlled at a liquid mass space velocity of 0.8 g of raw material / g of catalytically active metal / h. The equipment is continuously operated for 100 h, and the product is obtained after gas-liquid separation from the bottom of the reactor, and after multi-stage cooling.

[0053] After detection by gas chromatography and quantification by correction normalization, the conversion rate of the raw material 2,7-octadiene-1-ol is 99.6%, the selectivity of the product n-octanal is 98.1%, the selectivity of n-octanol is 1.1%, the n-octanal / n-octanol ratio is 89:1, and the selectivity of other components and high-boiling products is 0.8%.

[0054] Examples 2-6

[0055] A one-step process for preparing normal aldehydes, specifically, catalysts B~F were respectively filled into a fixed bed reactor equipped with a heating and insulation device, the reactor tube diameter was 20 mm, the tube length was 1000 mm, and the catalyst filling height was 150 mm. Before the reaction, the reactor was purged with nitrogen three times. After the reaction started, hydrogen with pre-introduced carbon monoxide (the molar ratio of carbon monoxide to hydrogen was shown in Table 2) was introduced from the top of the reactor controlled by a gas flow meter, while the raw material 2,7-octadiene-1-ol was pumped into a preheater by a plunger pump through a pipeline with heating, the preheating temperature was 50~150℃, then the material and hydrogen were mixed and introduced into the fixed bed reactor from the top of the reactor in parallel. The hydrogen flow rate was controlled so that the molar ratio of the raw material 2,7-octadiene-1-ol to hydrogen was 1:1.5~5, the reaction bed temperature was controlled at 50~150℃, the system pressure was controlled at 0.5~2 bar, and the residence time was controlled by the liquid mass space velocity, i.e. controlled at 0.5~10 grams of raw material / gram of catalytically active metal / h. The equipment was continuously operated for 100 h, the reaction liquid was taken out from the bottom of the reactor, and the reaction product was obtained after multi-stage cooling. After being detected by gas chromatography and quantified by correction normalization method, the reaction results were shown in Table 2.

[0056] Comparative Example 1:

[0057] Except that catalyst G was used instead of catalyst A used in Example 1, the parameters and control conditions of this comparative example were the same as those of Example 1. The reaction results were shown in Table 2.

[0058] Comparative Example 2:

[0059] Except that catalyst H was used instead of catalyst A used in Example 1, the parameters and control conditions of this comparative example were the same as those of Example 1. The reaction results were shown in Table 2.

[0060] Comparative Example 3:

[0061] Except that catalyst I was used instead of catalyst A used in Example 1, the parameters and control conditions of this comparative example were the same as those of Example 1. The reaction results were shown in Table 2.

[0062] Comparative Example 4:

[0063] Except that the reaction pressure was adjusted from 1.2 bar to 12 bar, the parameters and control conditions of this comparative example were the same as those of Example 2. The reaction results were shown in Table 2.

[0064] Comparative Example 5:

[0065] Except that the molar ratio of CO to H2 was adjusted from 0.001 to 0.1, the parameters and control conditions of this comparative example were the same as those of Example 2. The reaction results were shown in Table 2.

[0066] Comparative Example 6:

[0067] The reaction results are shown in Table 2.

[0068] Table 2

[0069]

[0070]

[0071] As can be seen from Table 2, the catalysts of the present application can better improve the dispersion of the active main metal and reduce the particle size of the active main metal after adding the activity promoter, thereby obtaining better synergistic catalysis, i.e. reducing the saturation hydrogenation activity and double bond migration activity of the active component main metal, promoting the isomerization of the allyl alcohol group in the raw material, inhibiting the migration of the double bond to other positions and the saturation hydrogenation of the double bond, and obtaining higher selectivity of n-butyl aldehyde and raw material conversion rate. In addition, the catalysts selected are activated at a lower catalyst calcination and reduction temperature, which improves the selectivity of the product prepared in the examples of the present application, avoids the generation of by-products with similar functional groups and carbon atom numbers, and reduces the difficulty of subsequent separation of the product and the process energy consumption.

[0072] In addition, Table 2 can also verify that the present application uses relatively low reaction temperature and pressure, and introduces a small amount of carbon monoxide in the hydrogen atmosphere, combined with the synergistic catalysis of the various active components of the catalyst used, to jointly control the double bond migration and saturation hydrogenation of the raw material to control its preferential conversion to n-alkyl aldehyde, thereby greatly reducing the occurrence of n-alkyl alcohol and other by-products. The selectivity of n-octyl aldehyde in the examples of the present application is 96-99%, and the obtained product contains only a small amount of n-alkyl alcohol saturation hydrogenation by-product, and the selectivity of other double bond migration and high boiling point products is almost 1%, almost no double bond migration by-product, and the aldehyde alcohol ratio is 44-247:1, which has obvious advantages compared with the prior art.

[0073] Examples 7-12

[0074] A one-step method for preparing normal aldehydes, specifically, catalysts A-F are respectively filled into a fixed bed reactor equipped with a heating and insulation device, the reactor has a tube diameter of 20 mm, a tube length of 1000 mm, and a catalyst filling height of 150 mm. Before the reaction, the reactor is purged with nitrogen three times. After the reaction starts, hydrogen with pre-introduced carbon monoxide (the molar ratio of carbon monoxide to hydrogen is shown in Table 3) is introduced from the top of the reactor by a gas flow meter, while the non-conjugated allyl alcohol raw material with a carbon-carbon double bond olefin group and a carbon atom number of 6-12 is pumped into a preheater by a plunger pump through a pipeline with heat tracing, the preheating temperature is 50-150°C, then the material is mixed with hydrogen and introduced into the fixed bed reactor from the top of the reactor. The hydrogen flow rate is controlled so that the molar ratio of the raw material to hydrogen is 1:1.5-5, the reaction bed temperature is controlled at 50-150°C, the system pressure is controlled at 0.5-2 bar, and the residence time is controlled by the liquid mass space velocity, i.e. controlled at 0.5-10 grams of raw material / gram of catalytically active metal / h. The equipment is continuously operated for 100 h, the reaction liquid is taken out from the bottom of the reactor, and the reaction product is obtained after multi-stage cooling. After detection by gas chromatography and quantitative determination by correction normalization method, the reaction results are shown in Table 3.

[0075] Table 3

[0076]

[0077]

[0078] Example 13:

[0079] A one-step method for preparing normal aldehyde, specifically, the catalyst F is filled into a fixed bed reactor equipped with a heating and insulation device, the reactor tube diameter is 20 mm, the tube length is 1000 mm, and the catalyst filling height is 150 mm. Before the reaction, the reactor is purged with nitrogen three times. After the reaction starts, the hydrogen with pre-introduced carbon monoxide (the molar ratio of carbon monoxide to hydrogen is 0.001) is introduced from the top of the reactor controlled by a gas flow meter, while the raw material 2,7-octadiene-1-ol is pumped into the preheater by a plunger pump through a pipeline with heating, the preheating temperature is 90°C, then the material and hydrogen are mixed and introduced into the fixed bed reactor from the top of the reactor in parallel flow. The hydrogen flow rate is controlled so that the molar ratio of the raw material 2,7-octadiene-1-ol to hydrogen is 1:1.5, the reaction bed temperature is controlled at 100°C, the system pressure is controlled at 1.1 bar, and the residence time is controlled by the liquid mass space velocity, i.e. controlled at 1.2 grams of raw material / gram of catalytically active metal / h. The equipment is continuously operated for 1000 h, the reactor bottom product is obtained by gas-liquid separation, and the reaction product is obtained after multi-stage cooling. After detection by gas chromatography and quantification by correction normalization method, the conversion rate of the raw material 2,7-octadiene-1-ol is stably at 97.9-99.5%, the selectivity of the product n-octyl aldehyde is stably at 98.1-99.2%, the selectivity of n-octanol is stably at 0.5-1.2%, the ratio of n-octyl aldehyde / n-octanol is stably at 82-200:1, and the selectivity of other components and high-boiling-point products is less than 1%.

[0080] It should be noted that the above is a further detailed description of the present application in combination with specific embodiments, and the specific embodiments of the present application cannot be limited to these descriptions; the size data of the embodiments does not limit the technical solutions, but only shows one specific working condition. For ordinary skilled persons in the technical field to which the present application belongs, some simple improvements and refinements can be made without departing from the concept of the present application, and all of them should be regarded as falling within the scope of protection of the present application.

Claims

1. A one-step method for preparing n-aldehydes, characterized in that, In a hydrogen atmosphere containing carbon monoxide, the non-conjugated allyl alcohol is contacted with a catalyst at 0.1~2.0 bar to react and generate a n-aldehyde. The catalyst is a supported catalyst, comprising an active metal component and an active additive; the active metal component is at least one of rhodium, ruthenium, and platinum, and the active additive is at least one of sulfur, selenium, tellurium, phosphorus, arsenic, antimony, bismuth, tin, cerium, and praseodymium. The non-conjugated allyl alcohol is an allyl alcohol compound having a carbon-carbon double bond alkenyl group at the other end of the molecule; the molar ratio of carbon monoxide to hydrogen in the hydrogen atmosphere containing carbon monoxide is 0.00001~0.01:1; the reaction temperature is 50~150℃.

2. The method for preparing n-aldehydes in one step according to claim 1, characterized in that, The active additive is at least one of the elements selected from sulfur, selenium, tellurium, phosphorus, bismuth, tin, and cerium.

3. The method for preparing n-aldehydes in one step according to claim 1, characterized in that, The catalyst support is at least one of alumina, activated carbon, silicon dioxide, titanium dioxide, zirconium oxide, molecular sieve, hydrotalcite, and kaolin.

4. The method for preparing n-aldehydes in one step according to claim 3, characterized in that, The catalyst support is one of silicon dioxide, titanium dioxide, and zirconium oxide.

5. The method for preparing n-aldehydes in one step according to claim 1, characterized in that, The particle size of the active component, the main metal, is 1~100 nm.

6. The method for preparing n-aldehydes in one step according to claim 5, characterized in that, The particle size of the active component, the main metal, is 2~50 nm.

7. The method for preparing n-aldehydes in one step according to claim 6, characterized in that, The particle size of the active component, the main metal, is 5~30 nm.

8. The method for preparing n-aldehydes in one step according to claim 1, characterized in that, The mass ratio of the active component main metal to the carrier is (0.001-0.05):

1.

9. The method for preparing n-aldehydes in one step according to claim 8, characterized in that, The mass ratio of the active agent to the carrier is (0.001-0.02):

1.

10. The method for preparing n-aldehydes in one step according to claim 1, characterized in that, The mass hourly space velocity (MSV) of the raw material is 0.1~20 g / g / h.

11. The method for preparing n-aldehydes in one step according to claim 10, characterized in that, The mass hourly space velocity (MSV) of the raw material is 0.5~10 g / g / h.

12. The method for preparing n-aldehydes in one step according to claim 1, characterized in that, The catalyst preparation steps include: subjecting the catalyst support after impregnation and adsorption of the active additive soluble salt, primary calcination, and impregnation and adsorption of the active component main metal soluble salt to secondary calcination at a temperature of 120~200℃; after calcination, reducing the catalyst in a hydrogen-containing atmosphere at 100-150℃ to obtain the catalyst.

13. The method for preparing n-aldehydes in one step according to claim 1, characterized in that, The molar ratio of hydrogen to raw materials in the hydrogen atmosphere containing carbon monoxide is 1.1 to 10:

1.

14. The method for preparing n-aldehydes in one step according to claim 13, characterized in that, The molar ratio of hydrogen to raw materials in the hydrogen atmosphere containing carbon monoxide is 1.5 to 5:

1.

15. The method for preparing n-aldehydes in one step according to claim 1, characterized in that, The molar ratio of carbon monoxide to hydrogen in the hydrogen atmosphere containing carbon monoxide is 0.00005 to 0.001:

1.

16. The method for preparing n-aldehydes in one step according to claim 1, characterized in that, The reaction is carried out in a hydrogen atmosphere containing carbon monoxide at a pressure of 0.1 to 1 bar.

17. The method for preparing n-aldehydes in one step according to claim 1, characterized in that, The reaction temperature is 60~100℃.

18. The method for preparing n-aldehydes in one step according to claim 1, characterized in that, The allyl alcohol compound having a carbon-carbon double bond alkenyl group at the other end of the molecule has 6 to 12 carbon atoms.

19. The method for preparing n-aldehydes in one step according to claim 18, characterized in that, The non-conjugated allyl alcohols include at least one of 2,5-hexadien-1-ol, 2,6-heptadien-1-ol, 2,7-octadien-1-ol, 2,8-nonadien-1-ol, 2,9-decadien-1-ol, 2,10-undecadien-1-ol, and 2,11-dodecadien-1-ol.

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