Solid super base catalyst, preparation method thereof and nitrile hydrolysis esterification method

Abstract

The invention provides a solid super base catalyst, a preparation method thereof and a nitrile hydrolysis esterification method. The preparation method of the solid super base catalyst comprises the following steps: 1) preparing a metal salt solution containing Ca, Al and Tl elements or containing Ca, Al, Tl and M elements; the M element comprises one or more of Sn, Mg, Ti, Mn, Cu, Zn and Cs; 2) preparing an alkali metal hydroxide solution; 3) under an ultrasonic condition, dropwise adding the metal salt solution and the alkali metal hydroxide solution into a container at the same time, and carrying out microwave heating on the reacted material after dropwise adding is completed; and then carrying out solid-liquid separation, washing and roasting to obtain the solid super base catalyst. According to the preparation method of the catalyst, the solid super-strong base catalyst is prepared from specific types of elements in combination with ultrasonic and microwave heating operations, the catalyst has high catalytic activity in the catalytic nitrile hydrolysis esterification reaction, a byproduct is discharged in the form of ammonia gas, and the whole process is green and environment-friendly.

Description

Technical Field

[0001] The invention relates to the technical field of chemical synthesis, and in particular to a solid superbase catalyst and a preparation method thereof, and a nitrile hydrolysis esterification method. Background Art

[0002] Nitrile compounds with cyano (CN) substitution (including monocyano nitrile compounds and dicyano nitrile compounds) are widely used in many fields such as chemical industry, medicine, and new materials. The cyano group can be used as an intermediate to transform into other functional groups and plays an important role in modern organic chemistry. The hydrolysis of nitrile compounds into amides and carboxylic acids is one of their most important applications.

[0003] The hydrolysis and esterification reaction of nitrile compounds includes hydrolysis and further esterification of the hydrolysis products. Among them, the hydrolysis of nitrile compounds is generally completed in the presence of strong inorganic acids or strong inorganic bases in the presence of water. Although the reaction conditions are mild and the conversion rate is high, it also has obvious disadvantages: first, the by-product problem. Acidic conditions will lead to the production of corresponding amine salts; second, ammonium salt waste residue will be generated during the reaction, and the generated wastewater with a high salt content is difficult to meet the discharge requirements of industrial wastewater. In addition, if carboxylic acid is to be obtained after hydrolysis under alkaline conditions, acid needs to be added for neutralization, which further aggravates the wastewater problem; in addition, the serious equipment corrosion caused by such catalysts is also a problem that cannot be ignored. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention discloses a solid superbase catalyst and a preparation method thereof, and a nitrile hydrolysis and esterification method. The solid superbase catalyst is used for catalyzing nitrile hydrolysis and esterification, and the operation is very simple and convenient, and the yield is high, the by-products are small, the three wastes are small, the process is clean and environmentally friendly, and the process is suitable for industrialized large-scale production.

[0005] In order to achieve the above technical objectives, on the one hand, the present invention provides a method for preparing a solid superbase catalyst, the method comprising the following steps:

[0006] (1) preparing a metal salt solution comprising Ca, Al, Tl, or comprising Ca, Al, Tl and M; wherein the M element comprises one or more of Sn, Mg, Ti, Mn, Cu, Zn, and Cs;

[0007] (2) preparing an alkali metal hydroxide solution;

[0008] (3) Under ultrasonic conditions, a metal salt solution and an alkali metal hydroxide solution are simultaneously added dropwise into a container, and after the addition is completed, the reacted material is subjected to microwave heating; and then solid-liquid separation, washing, and roasting are performed to obtain the solid superbase catalyst.

[0009] The above technical solution prepares a solid super-base catalyst. The solid base catalyst is an environmentally friendly green catalyst, which has an electron-rich center at the base position, and can usually capture hydrogen atoms in organic matter with a pKa of less than 26, and then activate the organic matter to achieve the purpose of catalysis. It has the advantages of easy control of reaction conditions, high catalytic activity, few side reactions, good selectivity, and low corrosion to equipment. The above technical solution can obtain a solid super-base catalyst by optimizing the active components and the preparation process, and its base strength H_ reaches more than 37, which can strengthen the nucleophilic addition reaction when the hydroxide attacks the cyano group during the catalytic nitrile hydrolysis and esterification process, and show better catalytic performance.

[0010] Specifically, the reaction formula of the hydrolysis and esterification reaction of nitrile compounds catalyzed by the solid superbase catalyst prepared by the above technical solution is as follows:

[0011]

[0012] The addition of the solid superbase catalyst prepared by the above technical solution makes the overall reaction system alkaline. Therefore, the by-products in the hydrolysis and esterification reaction of the nitrile compound of formula (1) using the monocyanonitrile compound as the raw material and the by-products in the hydrolysis and esterification reaction of the nitrile compound of formula (2) using the dicyanonitrile compound as the raw material will eventually be discharged from the reaction system in the form of ammonia gas, rather than generating ammonium salt solid waste, thereby limiting the generation of subsequent by-products from the source; and the generated ammonia gas can be recycled and used in other chemical processes, without causing environmental pollution and improving the economic benefits of the process; in addition, the change in the form of the by-products also greatly simplifies the post-processing difficulty of the hydrolysis and esterification reaction of the nitrile compound catalyzed by the solid superbase catalyst of the present invention. It is shown in the embodiments of the present invention that the corresponding crude ester compound can be obtained only by solid-liquid separation and extraction, reducing the difficulty of the overall process operation.

[0013] Furthermore, based on a large number of exploratory experiments, the research and development team of the present invention unexpectedly discovered that the solid superbase catalyst prepared with Ca, Al, Tl elements or Ca, Al, Tl and one or more elements of Sn, Mg, Ti, Mn, Cu, Zn, and Cs as active components showed advantages such as high catalyst activity, few by-products, and high yield when applied to nitrile hydrolysis and esterification reactions. It is speculated that in the catalyst preparation process of the above technical scheme, the Ca\Al\Tl elements formed a specific structure, thereby improving the catalytic performance of the superbase solid catalyst, and the addition of the M element further enhanced the catalytic activity of the catalyst; further combined with the ultrasonic treatment in step (3), the precipitation process of the catalyst preparation can be promoted to be more uniform, and microwave heating after the dropwise addition is completed can avoid the working condition of the catalyst skeleton collapse during the roasting operation, thereby synergistically optimizing and improving the structural stability of the prepared catalyst, and at the same time making the particle size of the prepared solid superbase catalyst more uniform and the particles smaller, which is beneficial to improving the catalytic activity of the catalyst.

[0014] It should be noted that the execution order of steps (1) and (2) in the above technical solution is not limited.

[0015] It should be noted that the metal salt solution described in the above technical solution is prepared by dissolving a metal salt containing a specific element in water. The present invention is not limited to the anion of the metal salt, as long as the selected metal salt is soluble in water. Those skilled in the art can set it according to actual conditions.

[0016] In a further example of the present invention, the ratio of different elements in the metal salt solution is explored and optimized. Optionally, the molar ratio of the elements Ca, Al, Tl, and M in the metal salt solution is (1-4): (1-3.5): (1-3): (0-2); by optimizing the dosage of different elements, the catalytic activity of the prepared solid superbase catalyst can be improved. In some optional examples of the present invention, the molar ratio of the elements Ca, Al, Tl, and M in the metal salt solution can be further selected as (1-4): (1-3.5): (1-3): (0.2-2), and further preferably (2-3.3): (2-3): (1.5-2.5): (0.5-1.2).

[0017] In a further example of the present invention, the concentration of the metal element in the metal salt solution is explored and optimized. Optionally, the concentration of Ca, Al, Tl element or Ca, Al, Tl, M element in the metal salt solution is 0.03-0.1 mol / ml, which is conducive to improving the stability of the subsequent metal salt solution and precipitant (alkali metal hydroxide solution) reaction system. In some optional examples of the present invention, the concentration of Ca, Al, Tl element or Ca, Al, Tl, M element in the metal salt solution can be further selected to be 0.05-0.08 mol / ml.

[0018] In a further example of the present invention, the concentration of hydroxide ions in the alkali metal hydroxide solution is explored and optimized. Optionally, the concentration of hydroxide ions in the alkali metal hydroxide solution is 0.04-0.4 mol / ml, which can improve the stability of the reaction system of the metal salt solution and the alkali metal hydroxide solution. In some optional examples of the present invention, the concentration of hydroxide ions in the alkali metal hydroxide solution can be further selected to be 0.1-0.2 mol / ml.

[0019] It can be understood by those skilled in the art that the alkali metal hydroxide solution is obtained by dissolving a specific alkali metal hydroxide in water. Since exothermic conditions may occur during the dissolution of the alkali metal hydroxide, in a further example of the present invention, the operation of cooling the alkali metal hydroxide solution to room temperature is also included to prevent heat from affecting subsequent processes.

[0020] In a further example of the present invention, the type of the alkali metal hydroxide is explored and optimized. Optionally, the alkali metal hydroxide includes one or more of NaOH, KOH, and LiOH. The optimization of the type of precipitant helps to improve the activity and selectivity of the catalyst and promote the improvement of the stability of the catalyst.

[0021] It should be noted that the metal salt solution and the alkali metal hydroxide solution are simultaneously added dropwise into the container for reaction in step (3), which is conducive to controlling the reaction process and improving operability. In addition, the present invention does not limit the specific operating equipment for the dropwise addition of the metal salt solution and the alkali metal hydroxide solution in step (3), and a plunger pump, a micro-syringe, a diaphragm pump, etc. can be selected. Those skilled in the art can make a selection according to actual working conditions, and the protection scope of the present invention is not limited thereby.

[0022] In a further example of the present invention, the control conditions of the ultrasonic operation in step (3) are explored and optimized. Optionally, the power of the ultrasonic operation is 100-700W, and the ultrasonic operation can promote the generation of uniform and finer precipitated particles in step (3).

[0023] In a further example of the present invention, the ultrasonic time in step (3) is greater than the dripping time, and the ultrasonication is continued for a certain time after the dripping is completed to improve the uniformity of the overall generated metal precipitate. The present invention does not limit the time for continuing the dripping after the dripping is completed, for example, the ultrasonication can be continued for about 3-15 minutes, and those skilled in the art can set it by themselves in the actual process.

[0024] In a further example of the present invention, the control conditions of the microwave heating operation in step (3) are explored and optimized. Optionally, the microwave heating has a power of 500-600W, a frequency of 0.8-2.0GHz, and a time of 2-50min. By optimizing the microwave operating conditions, appropriate heat can be provided to prevent the precipitation of metal salt compounds or the occurrence of metal salt inclusion conditions, thereby improving the safety of subsequent operations and the activity of the catalyst. In some optional examples of the present invention, microwave heating can be further selected for 6-15min.

[0025] It should be noted that the present invention is not limited to the specific operation of solid-liquid separation of the material after the metal precipitation reaction in step (3). The purpose of the solid-liquid separation operation is to separate the solid phase of the material after the reaction from the liquid phase. Those skilled in the art can choose a suitable solid-liquid separation method according to their needs, such as optional filtration, suction filtration, centrifugal separation, decantation, gravity sedimentation and the like, and the protection scope of the present invention is not limited thereby.

[0026] In a further example of the present invention, the control conditions of the washing operation in step (3) are explored and optimized. Optionally, the washing operation includes washing the solid obtained by solid-liquid separation until the pH is 7-8 to remove residual impurities on the surface of the solid, which is beneficial to improve the efficiency of the subsequent calcination activation operation and enhance the catalytic performance of the obtained solid superbase catalyst.

[0027] In a further example of the present invention, the control conditions of the calcination activation in the step (3) are explored and optimized. Optionally, the temperature of the calcination operation is 200-900°C; the calcination time is 1-16h, so as to avoid catalyst agglomeration and sintering and improve the catalytic activity and selectivity of the catalyst by optimizing the calcination conditions. Further, the calcination operation is carried out under an inert atmosphere; the inert atmosphere gas includes one or more of helium, neon, argon, krypton, xenon or nitrogen. In some optional examples of the present invention, the temperature of the calcination operation is preferably 500-800°C. In some optional examples of the present invention, the calcination time of the calcination operation is preferably 8-12h.

[0028] On the other hand, the present invention provides a solid superbase catalyst, which is prepared by the above-mentioned preparation method of the solid superbase catalyst.

[0029] Furthermore, the average particle size of the solid superbase catalyst is 20-50nm. The embodiment of the present invention shows the electron microscope morphology of the prepared solid superbase catalyst. The prepared nanoscale solid superbase catalyst can provide a larger specific surface area, which can not only reduce the diffusion resistance of the catalyst particles in the catalytic reaction, but also expose more active sites, thereby improving the activity of the catalyst and catalyzing the reaction more effectively.

[0030] On the other hand, the present invention proposes the use of the solid superbase catalyst in nitrile hydrolysis esterification reaction.

[0031] On the other hand, the present invention provides a nitrile hydrolysis and esterification method, which comprises the following steps: a nitrile compound undergoes a hydrolysis and esterification reaction with water and an alcohol compound under the action of the above-mentioned solid superbase catalyst.

[0032] In a further example of the present invention, based on a large amount of experimental data, the ratio of the reaction materials in the hydrolysis esterification reaction is explored and optimized. Optionally, the molar ratio of the nitrile compound, water and alcohol compound is 1: (1-10): (1-10); further optionally, according to the different cyano groups contained in the nitrile compound, when the nitrile compound is a monocyano nitrile compound, the molar ratio of the nitrile compound, water and alcohol compound is 1: (1.5-3.9): (1.5-3.9), when the nitrile compound is a polycyano nitrile compound, according to the change in the number of cyano groups, the molar ratio of the nitrile compound to water and alcohol compound will be proportionally reduced, for example, when the nitrile compound is a dicyano compound, the molar ratio of the nitrile compound, water and alcohol compound is 1: (3-7.8): (3-7.8), thereby improving the reaction efficiency and the yield of the product.

[0033] In a further example of the present invention, based on a large amount of experimental data, the amount of catalyst added in the hydrolysis esterification reaction is explored and optimized. Optionally, the amount of solid superbase catalyst added is 2%-8% of the mass of the nitrile compound; the optimization of the amount of catalyst is conducive to improving the reaction efficiency and promoting the efficient hydrolysis esterification reaction. In some optional examples of the present invention, the amount of solid superbase catalyst added is preferably 2%-6% of the mass of the nitrile compound.

[0034] In a further example of the present invention, the nitrile compound, water and alcohol compound may be mixed first, and then the solid super base catalyst may be added. Further, after the nitrile compound, water and alcohol compound are added to the reaction vessel, stirring (such as magnetic stirring, mechanical stirring, air flow stirring or manual stirring, etc.) may be used to promote material mixing, and further magnetic stirring may be used at 400 to 1000 revolutions per minute, and stirring for 20 to 30 minutes may be used to promote uniform mixing of materials in the reaction vessel. Further, after the solid super base catalyst is added, stirring (such as magnetic stirring, mechanical stirring, air flow stirring or manual stirring, etc.) may be used to promote full mixing of the solid phase catalyst and the liquid phase reaction material to obtain a uniform suspension.

[0035] It should be noted that the present invention is not limited to the specific structure and specifications of the reactor used for the hydrolysis and esterification reaction of the present invention. For example, a kettle reactor can be selected, and the reaction tube content of the kettle reactor can be selected to be 200-1000mL, and the pressure resistance is 10-20MPa, etc., but it is not limited to the listed range. Ordinary technicians in this field can select a reactor with suitable structure and specifications for hydrolysis and esterification reaction based on the technical solution of the present invention and through non-creative labor, and the technical solutions formed thereby are all within the protection scope of the present invention.

[0036] In a further example of the present invention, the control conditions of the hydrolysis esterification reaction were explored and optimized.

[0037] Optionally, the temperature of the hydrolysis and esterification reaction is 30-180°C, and the reaction is 1-12h. The reaction conditions of the nitrile hydrolysis and esterification reaction of the present invention are mild, and the operation is simple and easy to control, and it is suitable for industrial large-scale production. Further, the temperature of the hydrolysis and esterification reaction is 35-170°C. The optimization of the reaction temperature and time helps to control the pressure of the reaction system to promote the generation and recycling of ammonia, improve the reaction efficiency and operational safety, and promote full reaction. In some optional examples of the present invention, the temperature of the hydrolysis and esterification reaction is preferably 50-110°C.

[0038] Optionally, the hydrolysis and esterification reaction is carried out under an inert atmosphere; further, the inert atmosphere gas includes one or more of helium, neon, argon, krypton, xenon or nitrogen.

[0039] In a further example of the present invention, the types of reaction raw materials suitable for the hydrolysis esterification reaction are explored and optimized. Optionally, the nitrile compound includes one or more of aliphatic nitrile compounds, aromatic nitrile compounds and their derivatives. Further, the hydrocarbon group in the aliphatic nitrile compound includes an alkane with a carbon number of 2-10 and an olefin with a carbon number of 3-10; further, preferably, the hydrocarbon group in the aliphatic nitrile compound includes an alkane with a carbon number of 4-6 and an olefin with a carbon number of 4-6. Further, the cyano group in the aromatic nitrile compound and its derivatives is not directly connected to the benzene ring. Those skilled in the art can select a suitable spacer group for connecting the cyano group and the benzene ring according to the actual working conditions. For example, an alkyl group can be used as a spacer group to connect the cyano group and the benzene ring, and the protection scope of the present invention is not limited thereby. Further, the nitrile compound includes one or more of propionitrile, acrylonitrile, butyronitrile, 2-butenenitrile, isobutyronitrile, valeronitrile, isovaleronitrile, 2-methyl-2-butenenitrile, 2-methyl-3-butenenitrile, 2-pentenenitrile, 3-pentenenitrile, 2-methylvaleronitrile, 4-methylvaleronitrile, heptanenitrile, 2-methylhexanenitrile, octanonitrile, succinonitrile, 2-methylpropionitrile, glutaronitrile, 2-methylsuccinonitrile, adiponitrile, 2-methylglutaronitrile, 2,3-dimethylsuccinonitrile, pimelonitrile, 2-methyladiponitrile, suberonitrile, benzyl cyanide, 4-methoxyphenyl cyanide, 4-nitrophenyl cyanide, 1,3-phenylacetonitrile, and benzyl cyanide, but is not limited to the exemplified range, which reflects that the nitrile hydrolysis and esterification method of the present invention has wide universality and can be used in the hydrolysis and esterification process of various nitrile compounds.

[0040] In a further example of the present invention, the types of alcohol compounds for the hydrolysis esterification reaction are explored and optimized. Optionally, the alcohol compound is one or more of a monohydric alcohol or a polyhydric alcohol; the optional types of alcohol compounds of the present invention are wide, the raw materials are easy to obtain, and can be applied to the synthesis requirements of different ester compounds. In some optional examples of the present invention, the alcohol compound is preferably a monohydric alcohol; further preferably, one or more of methanol, ethanol, propanol, butanol, isopropanol, pentanol, isobutanol, hexanol, and octanol.

[0041] In a further example of the present invention, a post-processing step is also included for solid-liquid separation and extraction of the material after the hydrolysis and esterification reaction to obtain a crude ester compound.

[0042] Furthermore, the solid-liquid separation step is used to separate the solid phase catalyst from the liquid phase. Before the solid-liquid separation, the material after the hydrolysis and esterification reaction can be cooled to 0-25°C and allowed to stand, and then the solid-liquid separation is performed.

[0043] Further, the extraction operation is used to add an extractant to the liquid phase obtained by solid-liquid separation, extract the target product from the liquid phase to obtain an oil phase, and then obtain a crude ester compound by oil-water separation and concentration of the oil phase. The optional types of extractants include one or more of carboxylic acid esters, dichloromethane, ether, acetone or toluene. The optimization of the types of extractants is conducive to fully enriching the crude ester compounds obtained and improving economic benefits. Further, the carboxylic acid esters include one or more of methyl acetate, ethyl acetate, propyl acetate, butyl acetate, isopropyl acetate, amyl acetate, isobutyl acetate, hexyl acetate, and octyl acetate. Further, in the actual extraction operation, the mass ratio of the extractant to the aqueous phase solution can be selected as 0.02 to 1:1, and further selected as 0.05 to 0.15:1, so that the target product can be efficiently extracted from the aqueous phase to prevent the target product from being discharged as wastewater and causing waste. Further, the present invention also includes recycling the separated extractant and recycling it to reduce the process difficulty and save production costs.

[0044] Furthermore, the post-treatment process also includes recycling ammonia generated during the reaction, so that the ammonia can be used in other chemical process, improving the overall process economic benefits and reducing the generation of waste gas, providing a green and environmentally friendly nitrile hydrolysis and esterification method.

[0045] Furthermore, the post-treatment process also includes distilling the crude ester compound to obtain a high-quality lipid compound product, thereby meeting the requirements of different processes for the purity of the lipid compound product. It should be noted that the present invention is not limited to the specific operation mode and conditions of the distillation operation, and those skilled in the art can select appropriate distillation processes and equipment as needed, and the protection scope of the present invention is not limited thereby.

[0046] Furthermore, the post-treatment process also includes washing the catalyst obtained by solid-liquid separation to neutrality and calcining and activating it, so that the catalyst can be recycled to save process costs. It should be noted that the washing to neutrality described in the present invention refers to washing the material to a state where the pH value remains unchanged. Optionally, the calcination and activation operation includes calcining the washed and dried catalyst in a muffle furnace at 400-500°C for 5-10 hours.

[0047] Compared with the prior art, the invention has the following beneficial effects: the preparation method of the catalyst of the invention uses a specific type of element as an active component, and combines ultrasound and microwave heating operations to prepare a solid super-base catalyst, which exhibits better catalytic performance in the catalytic nitrile hydrolysis and esterification reaction, making the overall reaction conditions mild and easy to control, with a high product yield, and by-products discharged in the form of ammonia, effectively reducing the generation of three wastes and reducing the difficulty of post-treatment, which is in line with the development concept of green chemistry. The solid super-base catalyst and nitrile hydrolysis and esterification method of the invention have important industrial promotion and application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0049] Figure 1 The electron microscope image of the solid superbase catalyst prepared in Example 1 of the present invention is shown. DETAILED DESCRIPTION

[0050] In order to facilitate the understanding of the present invention, the present invention will be described more comprehensively below, and preferred embodiments of the present invention are given. However, it should be understood that these embodiments are only used for more detailed description and should not be understood as limiting the present invention in any form, i.e., not intended to limit the scope of protection of the present invention.

[0051] Unless otherwise defined, the technical terms used in the following examples have the same meanings as those generally understood by those skilled in the art to which the present invention belongs. The test reagents used in the following examples, unless otherwise specified, are all conventional biochemical reagents; the experimental methods, unless otherwise specified, are all conventional methods.

[0052] Example 1

[0053] A solid superbase catalyst, the preparation of which comprises the following steps:

[0054] (1) Ca(NO3)2·4H2O, Al(NO3)3·9H2O, TlNO3·3H2O, and Sn(NO3)4 were weighed according to n(Ca):n(Al):n(Tl):n(Sn) being 2.5:2.5:2:1, put into a container, added with deionized water to dissolve, and stirred until no precipitation occurred to obtain a metal salt solution; the total molar concentration of n(Ca), n(Al), n(Tl), and n(Sn) in the metal salt solution was 0.06 mol / mL;

[0055] (2) weighing an appropriate amount of NaOH and dissolving it in deionized water, stirring until no precipitation is obtained to obtain the alkali metal hydroxide solution, wherein the molar concentration of n(NaOH) in the alkali metal hydroxide solution is 0.16 mol / mL;

[0056] (3) The prepared metal salt solution and alkali metal hydroxide solution were simultaneously dripped into a three-necked flask at a rate of 0.6 mL / min by a plunger pump. During the dripping process, 400 W ultrasonic operation was continuously performed. After the dripping was completed, an inert gas was introduced and a 550 W, 1.6 GHz microwave was used for heating for 12 min. The filtered solid was washed with deionized water until the pH of the washing liquid was 7.0, vacuum dried, placed in a muffle furnace, and calcined at 700 ° C for 10 h. After cooling to room temperature, the solid superbase catalyst was obtained. The electron microscope morphology of the catalyst is shown in FIG. Figure 1 As shown, its average particle size is about 30nm; its H_ is determined by potentiometric titration to be above 37, which can rob hydrogen with a pKa of less than 26, meeting the standard of a solid superbase catalyst (catalyst with base strength H-≥31).

[0057] Example 2

[0058] A solid superbase catalyst, the process and raw material parameters for preparing the catalyst are the same as those in Example 1, except that: the metal salt solution comprises n(Ca):n(Al):n(Tl):n(Zn), the molar ratio is 2.5:2.5:2:0.3, and the total molar concentration of n(Ca):n(Al):n(Tl):n(Zn) in the metal salt solution is 0.04 mol / mL; the alkali metal hydroxide solution is a KOH solution, and the concentration thereof is 0.3 mol / mL; the power of the ultrasonic operation is 100 W, the control conditions of the microwave heating are power 400 W, frequency 0.9 GHz, and microwave heating for 5 min; the filtered solid is washed with ionized water to pH=7.5; the conditions of the roasting operation are 900° C. and roasting for 6 h.

[0059] Example 3

[0060] A solid superbase catalyst, the process and raw material parameters for preparing the catalyst are the same as those in Example 1, except that: the metal salt solution comprises n(Ca):n(Al):n(Tl), the molar ratio is 2.5:2.5:2, and the total molar concentration of n(Ca):n(Al):n(Tl) in the metal salt solution is 0.05 mol / mL; the alkali metal hydroxide solution is a NaOH solution, and the concentration thereof is 0.18 mol / mL; the control conditions of the microwave heating are a power of 550 W, a frequency of 1.2 GHz, and microwave heating for 11 min; the filtered solid is washed with ionized water to a pH of 7.2; the conditions of the roasting operation are 800° C. and roasting for 10 h.

[0061] Example 4

[0062] A solid superbase catalyst, the process and raw material parameters for preparing the catalyst are the same as those in Example 1, except that: the metal salt solution comprises n(Ca):n(Al):n(Tl):n(Mn), the molar ratio is 2.4:2.6:1.9:0.6, and the total molar concentration of n(Ca):n(Al):n(Tl):n(Mn) in the metal salt solution is 0.07 mol / mL; the alkali metal hydroxide solution is a NaOH solution, and the concentration thereof is 0.17 mol / mL; the power of the ultrasonic operation is 350 W, the control conditions of the microwave heating are power 530 W, frequency 1.5 GHz, and microwave heating for 10 min; the filtered solid is washed with ionized water to pH=7.1; the conditions of the roasting operation are 750° C. and roasting for 9 h.

[0063] Example 5

[0064] A solid superbase catalyst, the process and raw material parameters for preparing the catalyst are the same as those in Example 1, except that: the metal salt solution comprises n(Ca):n(Al):n(Tl):n(Cu), the molar ratio is 2.1:2.2:2.3:0.7, and the total molar concentration of n(Ca):n(Al):n(Tl):n(Cu) in the metal salt solution is 0.06 mol / mL; the alkali metal hydroxide solution is a KOH solution, and the concentration thereof is 0.15 mol / mL; the power of the ultrasonic operation is 300 W, the control conditions of the microwave heating are power 520 W, frequency 1.7 GHz, and microwave heating for 11 min; the filtered solid is washed with ionized water to pH=7.2; the conditions of the roasting operation are 720° C. and roasting for 8 h.

[0065] Example 6

[0066] A solid superbase catalyst, the process and raw material parameters for preparing the catalyst are the same as those in Example 1, except that: the metal salt solution comprises n(Ca):n(Al):n(Tl):n(Ti):n(Zn), the molar ratio is 3.3:2:2.5:0.3:0.6, and the total molar concentration of n(Ca):n(Al):n(Tl):n(Ti):n(Zn) in the metal salt solution is 0.05 mol / mL; the alkali metal hydroxide solution is a NaOH solution, and the concentration thereof is 0.18 mol / mL; the power of the ultrasonic operation is 600 W, the control conditions of the microwave heating are a power of 560 W, a frequency of 1.5 GHz, and microwave heating for 15 min; the filtered solid is washed with ionized water to a pH of 7.2; the conditions of the roasting operation are 700° C. and roasting for 12 h.

[0067] Example 7

[0068] A solid superbase catalyst, the process and raw material parameters for preparing the catalyst are the same as those in Example 1, except that: the metal salt solution comprises n(Ca):n(Al):n(Tl):n(Mg):n(Cs), the molar ratio is 2.7:2.8:1.5:0.5:0.7, and the total molar concentration of n(Ca):n(Al):n(Tl):n(Mg):n(Cs) in the metal salt solution is 0.08 mol / mL; the alkali metal hydroxide solution is a NaOH solution, and the concentration thereof is 0.2 mol / mL; the power of the ultrasonic operation is 620 W, the control conditions of the microwave heating are a power of 580 W, a frequency of 1.4 GHz, and microwave heating for 12 min; the conditions of the roasting operation are 750° C. and roasting for 12 h.

[0069] Comparative Example 1

[0070] A solid base catalyst, the process and raw material parameters for preparing the catalyst are the same as those in Example 1, except that the metal salt solution only contains Al and Tl, and the molar ratio of the two is 2.5:2.

[0071] Comparative Example 2

[0072] A solid base catalyst, the process and raw material parameters for preparing the catalyst are the same as those in Example 1, except that the metal salt solution only contains Ca and Tl, and the molar ratio of the two is 2.5:2.

[0073] Comparative Example 3

[0074] A solid base catalyst, the process and raw material parameters for preparing the catalyst are the same as those in Example 1, except that the metal salt solution only contains Ca and Al, and the molar ratio of the two is 2.5:2.5.

[0075] Comparative Example 4

[0076] A solid base catalyst, the process and raw material parameters for preparing the catalyst are the same as those in Example 1, except that the metal salt solution only contains Ca, Al and Sn, and the molar ratio of the three is 2.5:2.5:1.

[0077] Comparative Example 5

[0078] A solid base catalyst, the process and raw material parameters for preparing the catalyst are the same as those in Example 1, except that the total molar concentration of n(Ca), n(Al), n(Tl), and n(Sn) in the metal salt solution is 0.15 mol / mL, and the molar concentration of n(NaOH) in the alkali metal hydroxide solution is 0.6 mol / mL, the power of the ultrasonic operation is 520 W; the filtered solid is washed with ionized water to pH=7.3; the conditions of the roasting operation are 900° C. and roasting for 6 hours.

[0079] Comparative Example 6

[0080] A solid base catalyst, the process and raw material parameters for preparing the catalyst are the same as those in Example 1, except that the power of the microwave heating is 200W.

[0081] Comparative Example 7

[0082] A solid base catalyst, the process and raw material parameters for preparing the catalyst are the same as those in Example 1, except that the frequency of the microwave heating is 0.2 GHz.

[0083] Comparative Example 8

[0084] A solid base catalyst, the process and raw material parameters for preparing the catalyst are the same as those in Example 1, except that the microwave heating time is 3 minutes.

[0085] Comparative Example 9

[0086] A solid base catalyst, the process and raw material parameters for preparing the catalyst are the same as those in Example 1, except that the solid after suction filtration is washed with ionized water to a pH of 8.5.

[0087] Comparative Example 10

[0088] A solid base catalyst, the process and raw material parameters for preparing the catalyst are the same as those in Example 1, except that the calcination operation conditions are 1000° C. and 10 hours.

[0089] Comparative Example 11

[0090] A solid base catalyst, the process and raw material parameters for preparing the catalyst are the same as those in Example 1, except that the calcination operation conditions are 700° C. and 24 hours.

[0091] Comparative Example 12

[0092] A solid base catalyst, the process and raw material parameters for preparing the catalyst are the same as those in Example 1, except that the power of the ultrasonic operation is 50W.

[0093] Test cases and comparative test cases

[0094] A nitrile hydrolysis and esterification method, in which a nitrile compound undergoes a hydrolysis and esterification reaction with water and an alcohol compound under the action of a solid superbase catalyst in Examples 1-7 or a solid base catalyst in Comparative Examples 1-12; and tail gas generated during the reaction is collected with dilute sulfuric acid to generate ammonium sulfate.

[0095] After the reaction is completed, the reaction liquid is cooled to about 5°C and allowed to stand for 1 hour. The catalyst is recovered by solid-liquid separation and about 0.05 mol of ethyl acetate is used to extract the target product in the aqueous phase. The upper oil phase is taken out and distilled under reduced pressure to obtain the corresponding crude ester compound.

[0096] The test example and the comparative test example also include distilling the crude ester compound to obtain the ester compound product corresponding to the nitrile compound. The distillation operation is carried out in a distillation tower, and the pressure of the distillation tower can be optionally controlled to be 40-50 kPa absolute pressure, and amyl acetate is obtained from the top of the tower and recovered and reused, and a high-quality ester compound product is obtained from the bottom of the tower. The ester compound product is subjected to HPLC analysis.

[0097] As shown in Table 1, Test Examples 1-12 and Comparative Test Examples 1-21 show the control conditions and reaction results of hydrolysis esterification reactions under different reaction conditions using the solid superbase catalyst of Examples 1-7 or the solid base catalyst of Comparative Examples 1-12.

[0098] Table 1

[0099]

[0100]

[0101] Test Example 13

[0102] Based on Test Example 1, the catalyst was recovered and applied in this test example. Specifically, after the solid-liquid separation operation, the solid phase catalyst was washed with water to be neutral, and then vacuum dried and placed in a muffle furnace at 500°C for 10 hours for activation. After cyclic testing, the solid superbase catalyst of the present invention can still maintain high catalytic efficiency after 4 applications.

[0103] The ester compound products were analyzed by HPLC under different recycling conditions. The results are shown in Table 2.

[0104] Table 2

[0105] project First application Second application The third application Fourth application Diethyl adipate product (g) 263.25 262.81 259.44 262.85 HPLC content (%) 95.7 95.2 95.9 95.1

[0106] It should be noted that the above contents are further detailed descriptions of the present invention in combination with specific implementation methods, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple improvements can be made without departing from the concept of the present invention, which should be regarded as falling within the scope of protection of the present invention.

Claims

1. A method for preparing a solid superbase catalyst, characterized in that: The following steps are involved: (1) preparing a metal salt solution comprising Ca, Al, Tl, or comprising Ca, Al, Tl and M; wherein the M element comprises one or more of Sn, Mg, Ti, Mn, Cu, Zn, and Cs; (2) preparing an alkali metal hydroxide solution; (3) Under ultrasonic conditions, the metal salt solution and the alkali metal hydroxide solution are simultaneously added dropwise to a container, and after the addition is completed, the reacted material is subjected to microwave heating; and then solid-liquid separation, washing, and roasting are performed to obtain the solid superbase catalyst.

2. The method for preparing a solid superbase catalyst according to claim 1, characterized in that: The molar ratio of the elements Ca, Al, Tl and M in the metal salt solution is (1-4): (1-3.5): (1-3): (0-2); preferably (1-4): (1-3.5): (1-3): (0.2-2), further preferably (2-3.3): (2-3): (1.5-2.5): (0.5-1.2); preferably, the concentration of Ca, Al, Tl elements or Ca, Al, Tl, M elements in the metal salt solution is 0.03-0.1 mol / ml, preferably 0.05-0.08 mol / ml; And / or, the alkali metal hydroxide includes one or more of NaOH, KOH, LiOH; Preferably, the concentration of hydroxide ions in the alkali metal hydroxide solution is 0.04-0.4 mol / ml, more preferably 0.1-0.2 mol / ml.

3. The method for preparing a solid superbase catalyst according to claim 1, characterized in that: In the step (3), the power of the ultrasonic operation is 100-700W; And / or, the microwave heating has a power of 500-600 W, a frequency of 0.8-2.0 GHz, and a time of 2-50 min; And / or, the washing operation comprises washing the solid obtained by solid-liquid separation until the pH value is 7-8; And / or, the calcination temperature is 200-900°C, preferably 500-800°C; the calcination time is 1-16h, preferably 8-12h.

4. A solid superbase catalyst, characterized in that Prepared by the preparation method of the solid superbase catalyst according to claims 1-3; Preferably, the average particle size of the solid superbase catalyst is 20-50 nm.

5. A nitrile hydrolysis esterification method, characterized in that, The nitrile compound undergoes a hydrolysis and esterification reaction with water and an alcohol compound under the action of the solid superbase catalyst described in claim 4.

6. The nitrile hydrolysis esterification method according to claim 5, characterized in that: The molar ratio of the nitrile compound, water and alcohol compound is 1:(1-10):(1-10); Preferably, when the nitrile compound is a monocyanonitrile compound, the molar ratio of the nitrile compound, water and alcohol compound is 1:(1.5-3.9):(1.5-3.9); And / or, the addition amount of the solid superbase catalyst is 2%-8% of the mass of the nitrile compound; preferably 2%-6%.

7. The nitrile hydrolysis esterification method according to claim 5, characterized in that: The temperature of the hydrolysis esterification reaction is 30-180°C, and the reaction time is 1-12h; Preferably, the temperature of the hydrolysis esterification reaction is 35-170°C, preferably 50-110°C; And / or, the hydrolysis and esterification reaction is carried out under an inert atmosphere.

8. The nitrile hydrolysis esterification method according to claim 5, characterized in that: The nitrile compound includes one or more of aliphatic nitrile compounds, aromatic nitrile compounds and derivatives thereof; Preferably, the hydrocarbon group in the aliphatic nitrile compound includes an alkane having 2 to 10 carbon atoms and an olefin having 3 to 10 carbon atoms; Preferably, the hydrocarbon group in the aliphatic nitrile compound includes an alkane having 4 to 6 carbon atoms and an alkene having 4 to 6 carbon atoms; Preferably, the nitrile compound includes one or more of propionitrile, acrylonitrile, butyronitrile, 2-butenenitrile, isobutyronitrile, valeronitrile, isovaleronitrile, 2-methyl-2-butenenitrile, 2-methyl-3-butenenitrile, 2-pentenenitrile, 3-pentenenitrile, 2-methylvaleronitrile, 4-methylvaleronitrile, heptanenitrile, 2-methylhexanenitrile, octanonitrile, succinonitrile, 2-methylpropionitrile, glutaronitrile, 2-methylsuccinonitrile, adiponitrile, 2-methylglutaronitrile, 2,3-dimethylsuccinonitrile, pimelonitrile, 2-methyladiponitrile, suberonitrile, benzyl cyanide, 4-methoxyphenyl cyanide, 4-nitrophenyl cyanide, 1,3-phenylacetonitrile, and benzyl cyanide; And / or, the alcohol compound is a monohydric alcohol; further preferably, it is one or more of methanol, ethanol, propanol, butanol, isopropanol, pentanol, isobutanol, hexanol and octanol.

9. The nitrile hydrolysis esterification method according to claim 5, characterized in that: The nitrile hydrolysis and esterification method further comprises a post-treatment process, wherein the post-treatment process comprises solid-liquid separation and extraction of the material after the hydrolysis and esterification reaction to obtain a crude ester compound; Preferably, the post-treatment process comprises cooling the material after the hydrolysis and esterification reaction to 0-25°C and letting it stand, and then performing solid-liquid separation; Preferably, the extractant of the extraction operation comprises one or more of carboxylic acid esters, dichloromethane, ether, acetone or toluene; Further preferably, the carboxylic acid ester includes one or more of methyl acetate, ethyl acetate, propyl acetate, butyl acetate, isopropyl acetate, pentyl acetate, isobutyl acetate, hexyl acetate, and octyl acetate.

10. The nitrile hydrolysis esterification method according to claim 9, characterized in that: The post-processing step also includes recycling the ammonia generated during the reaction; And / or, the post-processing step further comprises distilling the crude ester compound to obtain a high-quality lipid compound product; And / or, the post-treatment step further comprises washing the catalyst obtained by solid-liquid separation to neutrality and calcining and activating it.

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