Catalyst, preparation method and application of catalyst in preparation of isopentenal

Abstract

The invention relates to the technical field of chemical engineering, and discloses a catalyst, a preparation method and application of the catalyst in preparation of isopentenal. According to the catalyst for catalyzing isomerization rearrangement of 2-methyl-3-butyne-2-alcohol to prepare isopentenal, provided by the invention, the lanthanide metal oxide is utilized to modify the supported vanadium catalyst, so that the selectivity of the catalyst can be improved, and the yield of isopentenal is increased. According to the synthesis process of the isopentenal, 2-methyl-3-butene-2-alcohol can be isomerized and rearranged into the isopentenal by adopting a reactive distillation mode without using a toxic solvent, efficient and continuous production of the isopentenal is realized, meanwhile, under the catalytic action of the catalyst, the raw material can be converted into the isopentenal with high selectivity, the yield of the isopentenal is increased, and the yield of the isopentenal is increased. And under proper process conditions, hydrogen ions can be provided in the presence of a proper amount of water, so that the raw materials are promoted to be subjected to isomerization rearrangement reaction quickly, the surface temperature of the catalyst is reduced, and the carbon deposition phenomenon of the catalyst is relieved to a certain extent.

Description

Technical Field

[0001] The present application relates to the field of chemical technology, and in particular to a catalyst, a preparation method and application thereof in the preparation of isopentanal. Background Art

[0002] 3-Methyl-2-butenal, also known as isopentenal, is a pharmaceutical intermediate that can be used to synthesize fine chemical products such as citral, vitamin E and vitamin A. It can also be used as a component to prepare flavors for daily necessities and food.

[0003] There are many synthetic routes for isopentenal, one of which is prepared by isomerization rearrangement reaction using 2-methyl-3-butyn-2-ol (also known as 3-methyl-1-butyn-3-ol) as raw material. The reaction process is as follows:

[0004]

[0005] The above-mentioned synthesis route of isopentanal has the problems of high catalyst price, long reaction time, low isopentanal yield, and use of highly toxic solvents, which seriously hinder the industrial application of isopentanal. Summary of the invention

[0006] In view of this, the present application provides a catalyst for preparing isopentanal, a preparation method and application thereof in preparing isopentanal, aiming to solve at least one of the above problems to a certain extent.

[0007] In a first aspect, the present application provides a catalyst for catalyzing the isomerization rearrangement of 2-methyl-3-butyn-2-ol to prepare isopentenal; the catalyst comprises a carrier and an active component and an auxiliary agent supported on the carrier, the active component comprises a vanadium oxide, and the auxiliary agent comprises a lanthanide metal oxide;

[0008] Based on the mass of the catalyst, the content of the active component is 5%-10%, and the content of the auxiliary agent is 0.5%-3%.

[0009] In an optional embodiment, the auxiliary agent includes at least one of lanthanum oxide, cerium oxide, and praseodymium oxide.

[0010] In an optional embodiment, the carrier includes at least one of montmorillonite, silica, and molecular sieve.

[0011] In a second aspect, the present application provides a method for preparing a catalyst for catalyzing the isomerization rearrangement of 2-methyl-3-butyn-2-ol to prepare isopentenal, comprising the following steps:

[0012] S1, dissolving a vanadium source in an alkaline aqueous solution, adjusting the pH to a strongly acidic state, and then adding a lanthanide metal salt to dissolve and form an impregnation solution;

[0013] S2, mixing the impregnation liquid with the carrier, impregnating under ultrasonic conditions, and filtering to obtain a precursor;

[0014] S3, forming the precursor, drying it and then calcining it.

[0015] In an optional embodiment, S1 adds an inorganic salt when preparing the impregnation solution; the inorganic salt includes at least one of sodium sulfate, potassium sulfate, lithium sulfate, sodium carbonate, and potassium carbonate.

[0016] In an optional embodiment, the molar ratio of the inorganic salt to the vanadium source is 0.8-1.8:1.

[0017] In an optional embodiment, the carrier includes at least one of montmorillonite, silica, and molecular sieve.

[0018] In an optional embodiment, the ultrasonic conditions in S2 include: frequency 800kHz-1200kHz, time 12h-48h.

[0019] In an optional embodiment, the calcination conditions in S3 include: heating to 500°C-1200°C at a rate of 1°C / min-5°C / min and calcining for 4h-48h.

[0020] In a third aspect, the present application also provides the use of the catalyst described in the first aspect or the catalyst prepared by the preparation method described in the second aspect in the preparation of isopentanal.

[0021] In a fourth aspect, the present application also provides a synthesis process of isopentenal, comprising the following steps:

[0022] The reactants are fed into a reaction distillation tower filled with a catalyst, with the operating temperature of the tower bottom being 95°C-145°C, the reflux ratio of the tower top being 1-20:1 and the liquid hourly space velocity being 0.5h -1 -3h -1 The reaction is carried out under the conditions of, and isopentenal is taken out from the bottom of the tower;

[0023] The reactants include 2-methyl-3-butyn-2-ol and water in a mass ratio of 70:30-98:2;

[0024] The catalyst is the catalyst described in the first aspect of the present application or a catalyst prepared by the preparation method described in the second aspect of the present application.

[0025] In an optional embodiment, the operating temperature of the tower bottom is 134°C-143°C, the reflux ratio of the tower top is 5-15:1, and the liquid hourly space velocity is 1-3h -1 .

[0026] In an optional embodiment, the mass ratio of 2-methyl-3-butyn-2-ol to water in the reactants is 90:10-98:2.

[0027] In an optional embodiment, the ratio of the flow rate of the overhead produced liquid of the reactive distillation tower to the feed flow rate of the reactants is 0.08-0.2.

[0028] In an optional embodiment, the reactive distillation tower comprises a distillation section, a reaction section and a stripping section from top to bottom, and the number of theoretical plates of the distillation section is not less than 5, for example, can be 5-10.

[0029] In an optional embodiment, the filling height of the catalyst layer in the reaction section is 1 to 10 times, for example, 3 to 8 times, the inner diameter of the reaction section.

[0030] In an optional embodiment, the number of theoretical plates in the stripping section is not less than 5, for example, may be 5-10.

[0031] In an optional embodiment, the reactants further include a strong acid and weak base salt, and the added amount thereof is 0.01%-2% of the mass of 2-methyl-3-butyn-2-ol, for example, 0.05%-0.2%;

[0032] In an optional embodiment, the strong acid and weak base salt includes at least one of ammonium sulfate, ammonium chloride, copper sulfate, ferric chloride, aluminum chloride, and ferric sulfate.

[0033] The technical solution of this application has the following advantages:

[0034] The catalyst provided in the present application for catalyzing the isomerization rearrangement of 2-methyl-3-butyne-2-ol to prepare isopentanal uses a lanthanide metal oxide to modify a supported vanadium catalyst, thereby improving the activity, selectivity and stability of the catalyst, thereby improving the reaction efficiency and the yield of isopentanal. At the same time, the reaction conditions can be optimized so that the reaction can be carried out under milder conditions, simplifying the reaction operation and reducing production costs.

[0035] Additional aspects and advantages of the embodiments of the present application will be described and shown in part in the subsequent description, or explained through the implementation of the embodiments of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0037] Figure 1 is a process flow chart of an implementation method of the present application;

[0038] The reference numerals are described as follows:

[0039] 1. Reaction distillation tower; 2. Top collector; 3. Bottom collector; 4. Top condenser; 5. Bottom reboiler. DETAILED DESCRIPTION

[0040] The technical solutions in the embodiments of the present application are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application.

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the description and claims of this application and any variations thereof are intended to cover non-exclusive inclusions.

[0042] In the description of the embodiments of the present application, “plurality” means more than two, unless otherwise clearly and specifically defined.

[0043] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0044] "Scope" disclosed in the present application is limited in the form of lower limit and upper limit, and a given range is limited by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of a special range. The scope limited in this way can be including end values ​​or not including end values, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form a scope. For example, if the scope of 60-120 and 80-110 is listed for a specific parameter, it is understood that the scope of 60-110 and 80-120 is also expected. In addition, if the minimum range values ​​1 and 2 are listed, and if the maximum range values ​​3, 4 and 5 are listed, the following scope can be all expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5. In the present application, unless otherwise specified, the numerical range "ab" represents the abbreviation of any real number combination between a and b, wherein a and b are real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" are listed in this document, and "0-5" is just an abbreviation of these numerical combinations. In addition, when a parameter is expressed as an integer ≥ 2, it is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0045] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0046] The related technology uses a supported vanadium catalyst to isomerize 2-methyl-3-butyn-2-ol in a xylene solvent to obtain isopentenal, but the yield is low, about 82%; and due to the use of highly toxic solvents and a long reaction time (more than 4 hours), it is not suitable for industrial production.

[0047] In order to solve the problems existing in the above-mentioned related art, according to the first aspect of the present application, a catalyst for catalyzing the isomerization rearrangement of 2-methyl-3-butyn-2-ol to prepare isopentenal is provided, wherein the catalyst comprises a carrier and an active component and an auxiliary agent supported on the carrier, wherein the active component comprises a vanadium oxide, and the auxiliary agent comprises a lanthanide metal oxide;

[0048] Based on the mass of the catalyst, the content of the active component is 5%-10%, and the content of the auxiliary agent is 0.5%-3%.

[0049] The present application uses lanthanide metal oxides to modify the supported vanadium catalyst. By changing the coordination number and coordination environment, the electronic structure and active site density of the catalyst can be adjusted, thereby improving the catalytic performance such as the activity, selectivity and stability of the catalyst; at the same time, the lanthanide metal elements can also form alloys or oxides with active metal vanadium to further enhance the stability and catalytic activity of the catalyst, thereby improving the reaction efficiency and the yield of isopentanal. In addition, the catalyst of the present application can also optimize the reaction conditions, so that the reaction can be carried out under milder conditions, simplify the reaction operation, and reduce production costs.

[0050] The present application has found that if the content of active components in the catalyst is too high, the active components will agglomerate, which will reduce the catalytic effect. When the content of active components is too low, the catalytic activity will be insufficient. Therefore, the present application controls the content of active components within the range of 5%-10%, which can ensure the high catalytic activity of the catalyst. As an example, the content of active components in the catalyst can be 5%, 6%, 7%, 8%, 9%, 10%, etc. or within the range composed of any of the above values. Moreover, if the content of the auxiliary agent in the catalyst is too large, the conversion rate of the raw material 2-methyl-3-butyn-2-ol will be reduced. On the contrary, if the content of the auxiliary agent is too small, the selectivity of the target product isopentanal will be reduced. Therefore, the present application controls the content of the auxiliary agent within the range of 0.5%-3%, so that the catalyst can have both high activity and selectivity, ensuring efficient conversion of the raw material while improving the yield of the target product; as an example, the content of the auxiliary agent in the catalyst can be, for example, 0.5%, 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, etc. or within the range composed of any of the above values.

[0051] The atomic radius of lanthanide elements gradually decreases with the increase of atomic number. This phenomenon is called lanthanide contraction, which makes the atomic radius of two elements in the same family of lanthanide very close, thus determining that lanthanide elements are very similar in properties. Therefore, it can be understood that existing lanthanide metal oxides can be applied to the present application. As an example, in some embodiments of the present application, the auxiliary agent includes at least one of lanthanum oxide, cerium oxide, and praseodymium oxide.

[0052] Compared with catalysts with only active components, supported catalysts containing carriers have better stability and are easier to modify due to the low loss rate of active components. In some embodiments of the present application, at least one of montmorillonite, silica, and molecular sieve is selected as a carrier to improve the stability of the catalyst and ensure high catalytic activity.

[0053] According to a second aspect of the present application, there is provided a method for preparing a catalyst for catalyzing the isomerization rearrangement of 2-methyl-3-butyn-2-ol to prepare isopentenal, comprising the following steps:

[0054] S1, dissolving a vanadium source in an alkaline aqueous solution, adjusting the pH to a strongly acidic state, and then adding a lanthanide metal salt to dissolve the lanthanide metal salt to form an impregnation solution;

[0055] S2, mixing the impregnation liquid with the carrier, impregnating under ultrasonic conditions, and filtering to obtain a precursor;

[0056] S3, forming the precursor, drying it and then calcining it.

[0057] It is understandable that the vanadium source is soluble in an alkaline aqueous solution, and then the pH is adjusted to a strong acid (such as pH = 2-3), which can further dissolve the lanthanide metal salt completely to form a uniform impregnation solution containing vanadium and lanthanide elements, and then the impregnation solution is mixed with the carrier for ultrasonic impregnation, which can accelerate the loading rate and make the vanadium element and lanthanide element dispersed more evenly on the carrier, and finally the impregnated precursor is sequentially formed, dried and calcined to obtain a rare earth modified supported vanadium catalyst. The catalyst preparation method of the present application is simple, the process operation is simple, and industrial production can be realized.

[0058] It should be noted that S1 adds inorganic salts when preparing the impregnation solution, which can promote the uniform dispersion of vanadium and lanthanide elements on the carrier, form more active sites, and improve the catalytic activity of the catalyst. As an example, the inorganic salt can be at least one of sodium sulfate, potassium sulfate, lithium sulfate, sodium carbonate, and potassium carbonate. In some embodiments, the molar ratio of the inorganic salt to the vanadium source is 0.8-1.8:1. As an example, the molar ratio of the inorganic salt to the vanadium source can be 0.8:1, 1:1, 1.2:1, 1.4:1, 1.6:1, 1.8:1, etc. or within the range of any of the above values. The present application has found that if the molar ratio of the inorganic salt to the vanadium source is too large, the active sites will be covered by the metal elements in the inorganic salt, affecting the catalytic performance. On the contrary, if the molar ratio of the inorganic salt to the vanadium source is too small, the active sites will be unevenly distributed, easy to agglomerate, and affect the catalytic performance.

[0059] In an optional embodiment, the ultrasonic conditions in S2 include: frequency 800kHz-1200kHz, time 12h-48h. The above ultrasonic conditions can promote the uniform dispersion of vanadium and lanthanide elements in the impregnation solution on the carrier, thereby ensuring catalytic activity.

[0060] In an optional embodiment, the calcination conditions in S3 include: heating to 500°C-1200°C at a rate of 1°C / min-5°C / min and calcining for 4h-48h. The above calcination conditions can ensure the volatilization of light components to obtain the target product, while preventing the catalytic performance from being affected by carbon deposition. The present application found that if the heating rate is too fast, the calcination temperature is too high or the time is too long, carbon deposition will occur, and if the calcination temperature is too low or the time is too short, it is difficult to completely volatilize the light components, interfering with the active sites.

[0061] According to the third aspect of the present application, there is also provided the use of the catalyst described in the first aspect or the catalyst prepared by the preparation method described in the second aspect in the preparation of isopentanal.

[0062] According to the fourth aspect of the present application, the present application also provides a synthesis process of isopentenal, comprising the following steps:

[0063] The reactants are fed into a reaction distillation tower filled with a catalyst, with the operating temperature of the tower bottom being 95°C-145°C, the reflux ratio of the tower top being 1-20:1 and the liquid hourly space velocity being 0.5h -1 -3h -1 The reaction is carried out under the conditions of, and isopentenal is taken out from the bottom of the tower;

[0064] The reactants include 2-methyl-3-butyn-2-ol and water in a mass ratio of 70:30-98:2;

[0065] The catalyst is the catalyst described in the first aspect of the present application or a catalyst prepared by the preparation method described in the second aspect of the present application.

[0066] It is understandable that the raw material 2-methyl-3-butyn-2-ol is prone to side reactions during the isomerization rearrangement to isopentenal, such as the formation of isopentenal polymers, which leads to carbon deposition on the catalyst bed, clogging the reaction distillation tower and deactivating the catalyst. The synthesis process of isopentenal provided in the present application adopts a reactive distillation method, and can isomerize and rearrange 2-methyl-3-butene-2-ol into isopentenal without using toxic solvents, thereby realizing efficient and continuous production of isopentenal. At the same time, under the catalytic action of the catalyst described in the first aspect or the catalyst prepared by the preparation method described in the second aspect, the raw material 2-methyl-3-butyn-2-ol can be highly selectively converted into isopentenal, thereby improving the yield of isopentenal. Under appropriate process conditions, the presence of an appropriate amount of water can provide hydrogen ions to promote the rapid isomerization and rearrangement reaction of the raw material 2-methyl-3-butyn-2-ol, reduce the surface temperature of the catalyst, and thus alleviate the carbon deposition of the catalyst to a certain extent. At the same time, because water can form an azeotrope with the raw material 2-methyl-3-butyn-2-ol, the difference in relative volatility between the raw material 2-methyl-3-butyn-2-ol and the target product isopentenal is increased, thereby facilitating the complete separation of the raw material and the target product.

[0067] The present application has found that if the amount of water added is too large, the raw material conversion rate will be reduced, and the operating temperature in the reaction distillation tower will be too low, increasing the process energy consumption. On the contrary, if the amount of water added is too small, it will not prevent the catalyst from carbonizing and increase the separation degree between the raw material and the target product. As an example, the water content in the reactant can be 2%, 3%, 4%, 5%, 8%, 10%, 20%, 30%, etc. or within the range of any of the above values.

[0068] It is understood that when the operating temperature of the tower bottom is 95°C-145°C, the top reflux ratio is 1-20:1 and the liquid hourly space velocity is 0.5h -1 -3h -1 When the reaction of rearrangement of 2-methyl-3-butyn-2-ol to isopentenal can be ensured to proceed smoothly. As an example, the operating temperature of the tower bottom can be, for example, 95°C, 105°C, 115°C, 125°C, 130°C, 134°C, 137°C, 140°C, 143°C, 145°C, etc., or within the range of any of the above values; the top reflux ratio can be, for example, 1:1, 5:1, 10:1, 15:1, 20:1, etc., or within the range of any of the above values; the liquid hourly space velocity can be 0.5h -1 , 1h -1 , 1.5h -1 , 2h -1 , 2.5h -1 , 3h -1 or within the range consisting of the above arbitrary values.

[0069] In order to ensure the purity of the isopentanal extracted from the bottom of the tower, it is necessary to extract water from the top of the reactive distillation tower as much as possible. Therefore, the present application can achieve the above purpose by controlling the flow rate of the overhead produced liquid of the reactive distillation tower to the feed flow rate of the reactant to be 0.08-0.2. As an example, the ratio of the flow rate of the overhead produced liquid to the feed flow rate of the reactant can be, for example, 0.08, 0.1, 0.12, 0.14, 0.16, 0.18, 0.2, etc. or within the range composed of any of the above values.

[0070] In an optional embodiment, the reaction distillation tower is composed of a distillation section, a reaction section and a stripping section from top to bottom, the number of theoretical plates in the distillation section is not less than 5, for example, it can be 5 to 10; the filling height of the catalyst layer in the reaction section is 1 to 10 times the inner diameter of the reaction section, for example, it can be 3 to 8 times; the number of theoretical plates in the stripping section is not less than 5, for example, it can be 5 to 10. In this way, the separation effect can be guaranteed. If the number of plates is too small, the separation purity of the target product will be affected. On the contrary, if the number of plates is too large, the pressure drop at the top of the tower is large, resulting in too high a temperature in the bottom of the tower, easy generation of impurities, and increased energy consumption.

[0071] The present application has found that when an appropriate amount of strong acid and weak base salt is added to the reactants, the slightly acidic environment of the reaction system can be further enhanced, effectively preventing the occurrence of carbon deposition, which is conducive to the catalyst showing better catalytic performance. As an example, the addition amount of the strong acid and weak base salt can be, for example, 0.01%, 0.05%, 0.1%, 0.2%, 0.5%, 1%, 1.5%, 2%, etc. or within the range of any of the above values. In some embodiments, the strong acid and weak base salt includes at least one of ammonium sulfate, ammonium chloride, copper sulfate, ferric chloride, aluminum chloride, and ferric sulfate.

[0072] The present application is further described in detail below in conjunction with specific examples, and these examples should not be construed as limiting the scope of protection claimed in the present application. Where specific experimental steps or conditions are not specified in the examples and comparative examples, the conventional experimental steps or conditions described in the literature in the art can be used. Where the manufacturer of the reagents or instruments used is not specified, they are all conventional reagent products that can be obtained commercially.

[0073] In all embodiments and comparative examples of the present application, unit % represents weight percentage. Adopt ICP, XPS test catalyst composition, adopt GC test reaction solution, tower top produced liquid and tower bottom produced liquid composition. Calculate feedstock conversion, isopentanal selectivity and isopentanal yield according to the following formula.

[0074] Raw material conversion rate = 100% - (flow rate of overhead produced liquid * content of 2-methyl-3-butyn-2-ol in overhead produced liquid) / (feed flow rate * content of 2-methyl-3-butyn-2-ol in feed) * 100%.

[0075] Isoprenal selectivity = (flow rate of bottom produced liquid*content of isopentenal in bottom produced liquid) / (feed flow rate*content of 2-methyl-3-butyn-2-ol in feed-flow rate of top produced liquid*content of 2-methyl-3-butyn-2-ol in top produced liquid)*100%.

[0076] Isopentenal yield = raw material conversion rate * isopentenal selectivity * 100%.

[0077] Example 1: Preparation of Catalyst C1

[0078] 98.56 g of KOH was dissolved in 300 g of deionized water, heated to 80°C, and then 5.35 g of V2O5 and 3.35 g of anhydrous Na2SO4 were added with stirring to completely dissolve them. Concentrated H2SO4 was then added to adjust the pH value of the solution to 2.5. Finally, 1.28 g of La(NO3)3 and 1.29 g of Ce(NO3)3 were added and stirred to obtain an impregnation solution after complete dissolution. The impregnation solution was evenly mixed with 49.5 g of SiO2, and ultrasonically impregnated in an ultrasonic cleaner (frequency 1000 kHz) for 24 h. The vanadium catalyst blank sample was filtered to obtain the blank sample, which was placed in a molding machine for ball molding, and then placed in a 90°C oven for drying for 5 h. Finally, the temperature was raised to 600°C at a rate of 3°C / min and calcined for 5 h to prepare catalyst C1.

[0079] After testing, the composition of catalyst C1 includes: 8.80% of V oxide, 1.05% of La oxide, and 1.06% of Ce oxide.

[0080] Example 2: Preparation of Catalyst C2

[0081] 98.56 g of NaOH was dissolved in 300 g of deionized water, heated to 40°C, and then stirred to add 3.41 g of V2O5 and 4.52 g of anhydrous Na2SO4 to completely dissolve them. Concentrated H2SO4 was then added to adjust the pH of the solution to 2. Finally, 1.27 g of Ce(NO3)3 was added and stirred to obtain an impregnation solution after complete dissolution. The impregnation solution was evenly mixed with 50.3 g of molecular sieve, and placed in an ultrasonic cleaner (frequency 800 kHz) for ultrasonic impregnation for 24 hours. The vanadium catalyst blank sample was filtered to obtain the blank sample, and the blank sample was placed in a molding machine for ball molding, and then placed in a 90°C oven for drying for 8 hours. Finally, the temperature was raised to 1000°C at a rate of 2°C / min and calcined for 36 hours to prepare catalyst C2.

[0082] After testing, the composition of catalyst C2 includes: 5.73% of V oxide and 1.07% of Ce oxide.

[0083] Example 3: Preparation of Catalyst C3

[0084] 98.56 g of NaOH was dissolved in 300 g of deionized water, heated to 60°C, and then stirred to add 4.19 g of V2O5 and 4.76 g of anhydrous K2CO3 to completely dissolve them. Concentrated H2SO4 was then added to adjust the pH of the solution to 3. Finally, 2.36 g of Pr(NO3)3 and 1.35 g of La(NO3)3 were added and stirred to obtain an impregnation solution after complete dissolution. The impregnation solution was evenly mixed with 52.1 g of montmorillonite, and placed in an ultrasonic cleaner (frequency 1200 kHz) for ultrasonic impregnation for 48 hours. The vanadium catalyst blank sample was filtered to obtain the blank sample, and the blank sample was placed in a molding machine for ball molding, and then placed in a 90°C oven for drying for 48 hours. Finally, the temperature was increased to 1200°C at a rate of 4°C / min and calcined for 48 hours to prepare catalyst C3.

[0085] After testing, the composition of catalyst C3 includes: 6.47% of V oxide, 1.82% of Pr oxide, and 1.04% of La oxide.

[0086] Example 4: Preparation of Catalyst C4

[0087] 98.56 g of NaOH was dissolved in 300 g of deionized water, heated to 50°C, and then stirred to add 6.21 g of V2O5 and 5.01 g of anhydrous Na2CO3 to completely dissolve them. Concentrated H2SO4 was then added to adjust the pH of the solution to 2.5. Finally, 0.66 g of Pr(NO3)3 was added and stirred to dissolve completely to obtain an impregnation solution. The impregnation solution was evenly mixed with 51.2 g of montmorillonite, and placed in an ultrasonic cleaner (frequency 900 kHz) for ultrasonic impregnation for 12 hours. The vanadium catalyst blank sample was filtered to obtain the blank sample, and the blank sample was placed in a molding machine to form a ball, and then placed in a 90°C oven to dry for 12 hours. Finally, the temperature was raised to 800°C at a rate of 5°C / min and calcined for 48 hours to prepare catalyst C4.

[0088] After testing, the composition of catalyst C4 includes: 9.84% of V oxide and 0.52% of Pr oxide.

[0089] Example 5: Preparation of Catalyst C5

[0090] The preparation method of catalyst C5 is basically the same as that of Example 1, the only difference being that no Na2SO4 is added to the impregnation solution.

[0091] After testing, the composition of catalyst C5 includes: 8.78% of V oxide, 0.92% of La oxide, and 0.89% of Ce oxide.

[0092] Example 6: Preparation of isopentanal

[0093] like Figure 1 As shown, a reaction distillation tower 1 with a tower diameter of 30 mm is used, which consists of a distillation section, a reaction section and a stripping section from top to bottom. The distillation section has 10 theoretical plates. The reaction section is filled with catalyst C1, the catalyst bed height is 150 mm, and the stripping section has 10 theoretical plates.

[0094] The reaction liquid consists of 0.05% ammonium sulfate, 3.32% water, 96.45% 2-methyl-3-butyn-2-ol and 0.18% other ingredients. The reaction liquid enters the reaction distillation tower from the feed line below the reaction section at a flow rate of 6.50 g / min. The liquid hourly space velocity is about 2 h -1 . The operating pressure of the reaction distillation tower is atmospheric pressure. The top condenser 4 uses 25°C circulating water as the refrigerant. The bottom operating temperature is 134-135°C. The heat source is provided by the bottom reboiler 5. The reflux and extraction ratio of the condensate outflowing from the top condenser 4 of the reaction distillation tower is 10:1. The flow rate of the top extraction liquid is 0.79g / min to the top collector 2. The top extraction liquid is composed of: 27.32% water, 72.61% 2-methyl-3-butyn-2-ol, and 0.07% others. The bottom liquid is extracted at a flow rate of 5.71g / min to the bottom collector 3. The bottom extraction liquid is composed of: 99.32% isopentanal and 0.68% others.

[0095] Through calculation, it was found that the conversion rate of 2-methyl-3-butyn-2-ol in this embodiment was 90.85%, the selectivity of isopentanal was 99.57%, and the yield of isopentanal was 90.46%.

[0096] In this embodiment, the catalyst operation cycle is 3500h.

[0097] Example 7: Preparation of isopentenal

[0098] A reaction distillation tower with a tower diameter of 30 mm was used, which consists of a distillation section, a reaction section and a stripping section from top to bottom. The distillation section has 10 theoretical plates. The reaction section is filled with catalyst C1 with a catalyst bed height of 150 mm. The stripping section has 10 theoretical plates.

[0099] The reaction liquid consists of 3.38% water, 96.45% 2-methyl-3-butyn-2-ol and 0.18% other. The reaction liquid enters the reaction distillation tower from the feed line below the reaction section at a flow rate of 6.50 g / min. The liquid hourly space velocity is about 2 h -1. The operating pressure of the reaction distillation tower is atmospheric pressure. The top condenser uses 25℃ circulating water as the refrigerant. The bottom operating temperature is 134~135℃, and the heat source is provided by the bottom reboiler. The reflux and production ratio of the condensate flowing out of the top condenser of the reaction distillation tower is 10:1. The flow rate of the top produced liquid is 0.79g / min. The composition of the top produced liquid is: 25.46% water, 74.41% 2-methyl-3-butyn-2-ol, and 0.13% others. The bottom liquid is produced at a flow rate of 5.65g / min at the bottom of the tower. The composition of the bottom produced liquid is: 98.74% isopentanal and 1.26% others.

[0100] Through calculation, it was found that the conversion rate of 2-methyl-3-butyn-2-ol in this embodiment was 89.91%, the selectivity of isopentanal was 98.97%, and the yield of isopentanal was 88.99%.

[0101] In this embodiment, the catalyst operation cycle is 900h.

[0102] Example 8: Preparation of isopentanal

[0103] A reaction distillation tower with a tower diameter of 30 mm is used, which consists of a distillation section, a reaction section and a stripping section from top to bottom. The distillation section has 8 theoretical plates. The reaction section is filled with catalyst C2 with a catalyst bed height of 200 mm. The stripping section has 8 theoretical plates.

[0104] The reaction liquid consists of 0.05% aluminum chloride, 4.12% water, 95.61% 2-methyl-3-butyn-2-ol, and 0.22% other. The reaction liquid enters the reaction distillation tower from the feed line below the reaction section at a flow rate of 7.0 g / min, and the liquid hourly space velocity is 1.5 h -1 . The operating pressure of the reaction distillation tower is atmospheric pressure. The top condenser uses 25℃ circulating water as the refrigerant. The bottom operating temperature is 139~141℃, and the heat source is provided by the bottom reboiler. The reflux and production ratio of the condensate outflowing from the top condenser of the reaction distillation tower is 5:1. The flow rate of the top produced liquid is 1.02g / min. The composition of the top produced liquid is: 28.27% water, 71.61% 2-methyl-3-butyn-2-ol, and 0.12% others. The bottom liquid is produced at a flow rate of 5.98g / min at the bottom of the tower. The composition of the bottom produced liquid is: 99.06% isopentanal and 0.94% others.

[0105] Through calculation, it was found that the conversion rate of 2-methyl-3-butyn-2-ol in this embodiment was 89.09%, the selectivity of isopentanal was 99.35%, and the yield of isopentanal was 88.51%.

[0106] In this embodiment, the catalyst operation cycle is 4500h.

[0107] Example 9: Preparation of isopentenal

[0108] A reaction distillation tower with a tower diameter of 30 mm was used, which consists of a distillation section, a reaction section and a stripping section from top to bottom. The distillation section has 15 theoretical plates. The reaction section is filled with catalyst C3 with a catalyst bed height of 200 mm. The stripping section has 15 theoretical plates.

[0109] The reaction liquid consists of 0.2% ferric sulfate, 2.94% water, 96.80% 2-methyl-3-butyn-2-ol and 0.06% other. The reaction liquid enters the reaction distillation tower from the feed line below the reaction section at a flow rate of 9.0 g / min, and the liquid hourly space velocity is about 1.9 h -1 . The operating pressure of the reaction distillation tower is atmospheric pressure. The top condenser uses 25℃ circulating water as the refrigerant. The bottom operating temperature is 141~143℃, and the heat source is provided by the bottom reboiler. The reflux and production ratio of the condensate flowing out of the top condenser of the reaction distillation tower is 15:1. The flow rate of the top produced liquid is 0.83g / min. The composition of the top produced liquid is: 31.88% water, 68.02% 2-methyl-3-butyn-2-ol, and 0.10% others. The bottom liquid is produced at a flow rate of 8.17g / min at the bottom of the tower. The composition of the bottom produced liquid is: 97.25% isopentanal and 2.75% others.

[0110] Through calculation, it was found that in this embodiment, the conversion rate of 2-methyl-3-butyn-2-ol was 93.52%, the selectivity of isopentanal was 97.52%, and the yield of isopentanal was 91.20%.

[0111] In this embodiment, the catalyst operation cycle is 3000h.

[0112] Example 10: Preparation of isopentenal

[0113] A reaction distillation tower with a tower diameter of 30 mm is used, which consists of a distillation section, a reaction section and a stripping section from top to bottom. The distillation section has 10 theoretical plates. The reaction section is filled with catalyst C4 with a catalyst bed height of 100 mm. The stripping section has 8 theoretical plates.

[0114] The reaction liquid consists of 0.1% ferric chloride, 3.21% water, 96.57% 2-methyl-3-butyn-2-ol and 0.12% other. The reaction liquid enters the reaction distillation tower from the feed line below the reaction section at a flow rate of 5.0 g / min, and the liquid hourly space velocity is 2.1 h -1. The operating pressure of the reaction distillation tower is atmospheric pressure. The top condenser uses 25℃ circulating water as the refrigerant. The bottom operating temperature is 136~138℃, and the heat source is provided by the bottom reboiler. The reflux and production ratio of the condensate flowing out of the top condenser of the reaction distillation tower is 5:1. The flow rate of the top produced liquid is 0.79g / min. The composition of the top produced liquid is: 20.32% water, 79.43% 2-methyl-3-butyn-2-ol, and 0.25% others. The bottom liquid is produced at a flow rate of 4.21g / min at the bottom of the tower. The composition of the bottom produced liquid is: 98.33% isopentanal and 1.67% others.

[0115] Through calculation, it was found that in this embodiment, the conversion rate of 2-methyl-3-butyn-2-ol was 87.00%, the selectivity of isopentanal was 98.54%, and the yield of isopentanal was 85.73%.

[0116] In this embodiment, the catalyst operation cycle is 3500h.

[0117] Example 11: Preparation of isopentenal

[0118] A reaction distillation tower with a tower diameter of 30 mm is used, which consists of a distillation section, a reaction section and a stripping section from top to bottom. The distillation section has 10 theoretical plates. The reaction section is filled with catalyst C4 with a catalyst bed height of 100 mm. The stripping section has 15 theoretical plates.

[0119] The reaction liquid consists of: 0.01% copper sulfate, 3.14% water, 96.73% 2-methyl-3-butyn-2-ol, and 0.12% other. The reaction liquid enters the reaction distillation tower from the feed line below the reaction section at a flow rate of 6.5 g / min, and the liquid hourly space velocity is about 2.8 h -1 . The operating pressure of the reaction distillation tower is atmospheric pressure. The top condenser uses 25℃ circulating water as the refrigerant. The bottom operating temperature is 136~138℃, and the heat source is provided by the bottom reboiler. The reflux and production ratio of the condensate flowing out of the top condenser of the reaction distillation tower is 5:1. The top production flow rate is 1.16g / min. The top production liquid is composed of: 17.65% water, 80.11% 2-methyl-3-butyn-2-ol, and 2.24% others. The bottom liquid is produced at a flow rate of 5.34g / min at the bottom of the tower. The bottom production liquid is composed of: 98.53% isopentanal and 1.47% others.

[0120] Through calculation, it was found that in this embodiment, the conversion rate of 2-methyl-3-butyn-2-ol was 85.22%, the selectivity of isopentanal was 98.20%, and the yield of isopentanal was 83.68%.

[0121] In this embodiment, the catalyst operation cycle is 3000h.

[0122] Example 12: Preparation of isopentenal

[0123] A reaction distillation tower with a tower diameter of 30 mm was used, which consists of a distillation section, a reaction section and a stripping section from top to bottom. The distillation section has 10 theoretical plates. The reaction section is filled with catalyst C1 with a catalyst bed height of 240 mm. The stripping section has 10 theoretical plates.

[0124] The reaction liquid consists of 0.2% ammonium chloride, 3.23% water, 96.45% 2-methyl-3-butyn-2-ol and 0.12% other ingredients. The reaction liquid enters the reaction distillation tower from the feed line below the reaction section at a flow rate of 2.8 g / min. The liquid hourly space velocity is about 0.5 h -1 . The operating pressure of the reaction distillation tower is atmospheric pressure. The top condenser uses 25℃ circulating water as the refrigerant. The bottom operating temperature is 134~135℃, and the heat source is provided by the bottom reboiler. The reflux and production ratio of the condensate flowing out of the top condenser of the reaction distillation tower is 20:1. The top production flow rate is 0.32g / min. The top production liquid is composed of: 28.25% water, 70.81% 2-methyl-3-butyn-2-ol, and 0.94% others. The bottom liquid is produced at a flow rate of 2.48g / min at the bottom of the tower. The bottom production liquid is composed of: 70.81% isopentanal and 0.94% others.

[0125] Through calculation, it was found that the conversion rate of 2-methyl-3-butyn-2-ol in this embodiment was 90.83%, the selectivity of isopentanal was 83.21%, and the yield of isopentanal was 91.61%.

[0126] In this embodiment, the catalyst operation cycle is 2700h.

[0127] Example 13

[0128] It is basically the same as Example 6, except that:

[0129] Using catalyst C5, the top extraction flow rate is 0.97g / min to the top collector, and the top extraction liquid has the following composition: 22.25% water, 76.27% 2-methyl-3-butyn-2-ol and 1.48% others; the bottom liquid is extracted at a flow rate of 5.53g / min to the bottom collector, and the bottom extraction liquid has the following composition: 93.31% isopentanal and 6.69% others.

[0130] Through calculation, it was found that in this embodiment, the conversion rate of 2-methyl-3-butyn-2-ol was 88.20%, the selectivity of isopentanal was 93.32%, and the yield of isopentanal was 87.60%.

[0131] In this embodiment, the catalyst operation cycle is 2900h.

[0132] Comparative Example 1

[0133] Preparation of catalyst D1: 98.56g KOH was dissolved in 300g deionized water, heated to 80°C, and then 5.35g V2O5 and 3.35g anhydrous Na2SO4 were added and stirred to completely dissolve to obtain an impregnation solution, the impregnation solution was mixed evenly with 49.5g SiO2, placed in an ultrasonic cleaner (frequency 1000kHz) for ultrasonic impregnation for 24h, filtered to obtain a vanadium catalyst blank sample, the blank sample was placed in a molding machine for ball molding, and then placed in a 90°C oven for drying for 5h, and finally heated to 600°C at a rate of 3°C / min for calcination for 5h to prepare catalyst D1. After testing, the composition of catalyst D1 includes: 8.92% V oxide.

[0134] The same method as in Example 6 was used to prepare isopentanal, with the flow rate of the tower top produced liquid being 1.32 g / min to the tower top collector, and the tower top produced liquid composition was: 16.35% water, 80.34% 2-methyl-3-butyn-2-ol, and 0.31% others. The tower bottom liquid was produced at a flow rate of 5.18 g / min to the tower bottom collector, and the tower bottom produced liquid phase composition was: 51.35% isopentanal and 48.76% others.

[0135] Through calculation, it was found that in this comparative example, the conversion rate of 2-methyl-3-butyn-2-ol was 82.45%, the selectivity of isopentanal was 51.35%, and the yield of isopentanal was 42.34%.

[0136] The catalyst operation cycle in this comparative example is 150 h.

[0137] Comparative Example 2

[0138] Isopentenal was prepared in the same manner as in Example 6, except that the reaction solution was composed of 0.05% ammonium sulfate, 99.77% 2-methyl-3-butyn-2-ol, and 0.18% others.

[0139] After testing, the flow rate of the tower top produced liquid to the tower top collector is 2.31g / min, and the composition of the tower top produced liquid is: 2-methyl-3-butyn-2-ol 85.82%, isopentanal 12.51%, and others 1.67%. The tower bottom liquid is produced at a flow rate of 4.19g / min to the tower bottom collector, and the composition of the tower bottom produced liquid is: isopentanal 87.11% and others 13.89%.

[0140] By calculation, it was found that in this comparative example, the conversion rate of 2-methyl-3-butyn-2-ol was 69.43%, the selectivity of isopentanal was 87.48%, and the yield of isopentanal was 60.74% (the isopentanal in the top extraction liquid was included in the calculation of the selectivity and yield of isopentanal).

[0141] In this comparative example, the catalyst operation cycle is shortened from 3500 h in Example 6 to 800 h.

[0142] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection created by this application.

Claims

1. A catalyst for catalyzing the isomerization rearrangement of 2-methyl-3-butyn-2-ol to prepare isopentenal; characterized in that: The catalyst comprises a carrier, an active component and a promoter supported on the carrier, wherein the active component comprises vanadium oxide, and the promoter comprises lanthanide metal oxide; Based on the mass of the catalyst, the content of the active component is 5%-10%, and the content of the auxiliary agent is 0.5%-3%.

2. The catalyst according to claim 1, characterized in that The auxiliary agent includes at least one of lanthanum oxide, cerium oxide, and praseodymium oxide; And / or, the carrier includes at least one of montmorillonite, silica, and molecular sieve.

3. A method for preparing a catalyst for catalyzing the isomerization rearrangement of 2-methyl-3-butyn-2-ol to prepare isopentenal, characterized in that: The steps include: S1, dissolving a vanadium source in an alkaline aqueous solution, adjusting the pH to a strongly acidic state, and then adding a lanthanide metal salt to dissolve the lanthanide metal salt to form an impregnation solution; S2, mixing the impregnation liquid with the carrier, impregnating under ultrasonic conditions, and filtering to obtain a precursor; S3, forming the precursor, drying it and then calcining it.

4. The method for preparing the catalyst according to claim 3, characterized in that: S1: adding an inorganic salt when preparing the impregnation solution; the inorganic salt includes at least one of sodium sulfate, potassium sulfate, lithium sulfate, sodium carbonate, and potassium carbonate, and / or the molar ratio of the inorganic salt to the vanadium source is 0.8-1.8:

1.

5. The method for preparing the catalyst according to claim 3, characterized in that: The carrier includes at least one of montmorillonite, silicon dioxide and molecular sieve; And / or, the ultrasonic conditions in S2 include: frequency 800kHz-1200kHz, time 12h-48h; And / or, the calcination conditions in S3 include: heating to 500°C-1200°C at a rate of 1°C / min-5°C / min and calcining for 4h-48h.

6. Use of the catalyst according to any one of claims 1 to 2 or the catalyst prepared by the preparation method according to any one of claims 3 to 5 in the preparation of isopentanal.

7. A synthesis process for isopentenal, characterized in that: The method comprises the following steps: The reactants are fed into a reaction distillation tower filled with a catalyst, with the operating temperature of the tower bottom being 95°C-145°C, the reflux ratio of the tower top being 1-20:1 and the liquid hourly space velocity being 0.5h -1 -3h -1 The reaction is carried out under the conditions of, and isopentenal is taken out from the bottom of the tower; The reactants include 2-methyl-3-butyn-2-ol and water in a mass ratio of 70:30-98:2; The catalyst is the catalyst described in any one of claims 1-2 or a catalyst prepared by the preparation method described in any one of claims 3-5.

8. The synthesis process of prenylaldehyde according to claim 7, characterized in that, The operating temperature of the tower bottom is 134°C-143°C, the reflux ratio of the tower top is 5-15:1, and the liquid hourly space velocity is 1h -1 -3h -1 ; And / or, the mass ratio of 2-methyl-3-butyn-2-ol to water in the reactants is 90:10-98:2; And / or, the ratio of the flow rate of the overhead produced liquid of the reactive distillation tower to the feed flow rate of the reactants is 0.08-0.

2.

9. The synthesis process of prenylaldehyde according to claim 7, characterized in that: The reactive distillation tower is composed of a distillation section, a reaction section and a stripping section from top to bottom, and the number of theoretical plates in the distillation section is not less than 5, preferably 5-10; and / or, the catalyst layer filling height in the reaction zone is 1-10 times, preferably 3-8 times, the inner diameter of the reaction zone; And / or, the number of theoretical plates of the stripping section is not less than 5, preferably 5-10.

10. The synthesis process of isopentenal according to any one of claims 7 to 9, characterized in that: The reactants also include a strong acid and weak base salt, the addition amount of which is 0.01%-2% of the mass of 2-methyl-3-butyn-2-ol, preferably 0.05%-0.2%; And / or, the strong acid and weak base salt includes at least one of ammonium sulfate, ammonium chloride, copper sulfate, ferric chloride, aluminum chloride, and ferric sulfate.

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