A catalyst for synthesizing o-chlorobenzonitrile and preparation method thereof

Abstract

The invention discloses a catalyst for synthesizing o-chlorobenzonitrile and a preparation method thereof, and relates to the technical field of catalysts. A molecular sieve is used as a carrier, and the active components include the following general formula components in terms of atomic number ratio: V 1.0 Fe a Se b M c N d X e O m , wherein: M is a rare earth element; N is a mixture of Cs and Mg in an atomic ratio of 1:(1-2); X is a mixture of Ta, Ga, Ge, Os, Cr, and Sn in an atomic ratio of 1:(0.3-0.5):(0.1-0.3):(0.01-0.03):(1-2):(0.1-0.3); a is 0.05-0.1; b is 0.01-0.04; c is 0.08-0.12; d is 0.08-0.15; e is 0.1-0.2; and m is the number of oxygen atoms required to satisfy the valence of the element. The catalyst has a significant catalytic effect, reaction conversion rate, selectivity and yield.

Description

Technical Field

[0001] The invention relates to the technical field of catalysts, and in particular to a catalyst for synthesizing o-chlorobenzonitrile and a preparation method thereof. Background Art

[0002] o-Chlorobenzonitrile, also known as o-chlorobenzonitrile and 2-chlorobenzonitrile, is an important fine chemical and organic synthesis intermediate. For example, o-chlorobenzonitrile is used in the production of pesticides, medicines, polymers, dyes, pigments; synthesizing new antimalarial drugs such as nitroquine, antihypertensive drugs such as valsartan, and uracil herbicides. The simplest and most advanced method for preparing o-chlorobenzonitrile is the direct ammoxidation process of o-chlorotoluene, which has matured in the past three decades. It has developed rapidly in recent years because of its short process flow, simple operation, good product quality, and high yield. This process is highly dependent on catalysts, and the selection of the active components and forms of the catalyst is crucial.

[0003] The most common and effective catalytic system for preparing o-chlorobenzonitrile by direct ammoxidation process of o-chlorotoluene is vanadium-based catalyst, such as VP, V-Cr and Sb-Fe system, usually with aluminum oxide, silicon carbide, silicon oxide as carrier, adopting fixed bed or coarse particle baffle fluidized bed process. However, these process product yields are not very high. Meanwhile, in order to solve the problem of reaction heat removal and catalyst stability, inert diluents such as nitrogen, water, etc. are usually added in the reaction process. But this can only partially overcome the above-mentioned defects, and these problems are not fundamentally solved, such as reactor amplification, which will inevitably lead to reaction heat removal difficulties, product yield and quality decline, reactor effective load reduction, catalyst life shortening and many other "engineering amplification" problems. Thereby in industrial production, it is difficult to give play to their technical level, and the existence of process water causes many inconveniences to product post-treatment, and also has serious corrosion to equipment.

[0004] In order to solve the above problems, the Chinese invention patent with authorization announcement number CN1187320C discloses a fluidized bed catalyst for preparing o-chlorobenzonitrile, which mainly solves the problems that the catalyst in the prior art is difficult to adapt to the fluidized bed or has poor reaction selectivity, and the reactor has a large amplification effect, is difficult to remove heat, and has a small reactor load. The invention is expressed by adopting the chemical formula as follows: V 1.0 Cr a B b X c Y d Z e O m, wherein X is at least one selected from P or As; Y is at least one selected from alkali metals or alkaline earth metal elements; C is at least one selected from Ni, Co, Pb, Fe, Mo or W, which solves the problem well and can be used for industrial production of o-chlorobenzonitrile. However, the selectivity and yield of o-chlorobenzonitrile in the synthesis process of o-chlorobenzonitrile using the catalyst need to be further improved.

[0005] Therefore, the development of a catalyst for synthesizing o-chlorobenzonitrile and a preparation method thereof that can adapt to fluidized bed operation, overcome the reaction engineering amplification effect and heat removal problems, have a high reaction load, a significant catalytic effect, and a high reaction conversion rate, selectivity and yield meets market demand, has broad market value and application prospects, and is of great significance to promoting the development of the catalyst field. Summary of the invention

[0006] The purpose of the present invention is to overcome the deficiencies of the prior art and to provide a catalyst for synthesizing o-chlorobenzonitrile and a preparation method thereof, which can adapt to fluidized bed operation, overcome the reaction engineering amplification effect and heat removal problems, have a high reaction load, a significant catalytic effect, and a high reaction conversion rate, selectivity and yield.

[0007] To achieve the above object, the technical solution adopted by the present invention is: a catalyst for synthesizing o-chlorobenzonitrile, with a molecular sieve as a carrier, and the active components include the following general components in terms of atomic number ratio: V 1.0 Fe a Se b M c N d X e O m , wherein: M is a rare earth element; N is a mixture of Cs and Mg in an atomic ratio of 1:(1-2); X is a mixture of Ta, Ga, Ge, Os, Cr, and Sn in an atomic ratio of 1:(0.3-0.5):(0.1-0.3):(0.01-0.03):(1-2):(0.1-0.3); the value range of a is 0.05-0.1; the value range of b is 0.01-0.04; the value range of c is 0.08-0.12; the value range of d is 0.08-0.15; the value range of e is 0.1-0.2; m is the number of oxygen atoms required to satisfy the valence of the element; the carrier molecular sieve in the catalyst is 40-70wt% by weight.

[0008] Preferably, the rare earth element is a mixture of Pr, Gd and Dy in a molar ratio of 1:(1-2):(1-2).

[0009] Preferably, the molecular sieve is at least one of MCM-48 molecular sieve, ZSM-8 molecular sieve, and SSZ-13 molecular sieve.

[0010] Another object of the present invention is to provide a method for preparing the catalyst for synthesizing o-chlorobenzonitrile, comprising the following steps: adding vanadium pentoxide, ferric oxide, selenium dioxide and molecular sieves to an oxalic acid solution, stirring evenly at 80-90° C., adding soluble salts containing M, N and X respectively to the above solution, and using a multi-energy field assisted treatment for 5-10 minutes to obtain a suspended mixture; spraying the suspended mixture slurry into a dry state, and then calcining to obtain a catalyst for synthesizing o-chlorobenzonitrile.

[0011] Preferably, the salts containing M, N, and X respectively are chloride salts or nitrate salts containing M, N, and X respectively.

[0012] Preferably, the mass ratio of the vanadium pentoxide to the oxalic acid solution is 1:(15-20).

[0013] Preferably, the mass percentage concentration of the oxalic acid solution is 10-15wt%.

[0014] Preferably, the multi-energy field includes ultrasound, microwave and steady magnetic field; the ultrasound frequency is 80-120kHz, and the power is 700-1200W; the microwave frequency is 2.1-2.6GHz, and the power is 900-1500W; the steady magnetic field strength is 0.5-2.5T.

[0015] Preferably, the drying temperature is 110-120° C. and the drying time is 5-8 hours.

[0016] Preferably, the calcination temperature is 550-850° C. and the calcination time is 5-10 h.

[0017] Due to the application of the above technical solution, the present invention has the following beneficial effects:

[0018] (1) The preparation method of the catalyst for synthesizing o-chlorobenzonitrile disclosed in the present invention has simple process, convenient operation, high preparation efficiency, small impact on the environment, low labor intensity and equipment dependence, is suitable for continuous large-scale production, and has high promotion and application value.

[0019] (2) The catalyst for synthesizing o-chlorobenzonitrile disclosed in the present invention uses a molecular sieve as a carrier, and the active components include the following general components in terms of atomic number ratio: V 1.0 Fe a Se b M c N d X e O m, wherein: M is a rare earth element; N is a mixture of Cs and Mg in an atomic ratio of 1:(1-2); X is a mixture of Ta, Ga, Ge, Os, Cr, and Sn in an atomic ratio of 1:(0.3-0.5):(0.1-0.3):(0.01-0.03):(1-2):(0.1-0.3); the value range of a is 0.05-0.1; the value range of b is 0.01-0.04; the value range of c is 0.08-0.12; the value range of d is 0.08-0.15; the value range of e is 0.1-0.2; m is the number of oxygen atoms required to satisfy the valence of the element; the carrier molecular sieve in the catalyst is 40-70wt% by weight. Through the reasonable selection of various components and content ratios, the prepared catalyst can adapt to fluidized bed operation, overcome the reaction engineering amplification effect and heat removal problems, have a high reaction load, a significant catalytic effect, and a high reaction conversion rate, selectivity and yield.

[0020] (3) The catalyst for synthesizing o-chlorobenzonitrile disclosed in the present invention can be suitable for fluidized bed operation through reasonable selection of preparation process parameters, effectively overcoming the reaction engineering amplification effect and heat removal problems of the catalyst, and has a high structural temperature and catalytic activity. The selectivity and yield of the catalytic reaction are significantly improved compared with the catalysts in the prior art. DETAILED DESCRIPTION

[0021] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art may think of other obvious variations.

[0022] Example 1

[0023] A catalyst for synthesizing o-chlorobenzonitrile, using a molecular sieve as a carrier, wherein the active components include the following general formula components in terms of atomic number ratio: V 1.0 Fe a Se b M c N d X e O m , wherein: M is a rare earth element; N is a mixture of Cs and Mg in an atomic ratio of 1:1; X is a mixture of Ta, Ga, Ge, Os, Cr, and Sn in an atomic ratio of 1:0.3:0.1:0.01:1:0.1; a is 0.05; b is 0.01; c is 0.08; d is 0.08; e is 0.1; m is the number of oxygen atoms required to satisfy the valence of the element; the carrier molecular sieve in the catalyst is 40wt% by weight.

[0024] The rare earth element is a mixture of Pr, Gd and Dy in a molar ratio of 1:1:1; and the molecular sieve is MCM-48 molecular sieve.

[0025] A preparation method of a catalyst for synthesizing o-chlorobenzonitrile comprises the following steps: adding vanadium pentoxide, ferric oxide, selenium dioxide and molecular sieve into an oxalic acid solution, stirring the mixture uniformly at 80°C, adding soluble salts containing M, N and X respectively into the solution, and using a multi-energy field to assist in treatment for 5 minutes to obtain a suspended mixture; spraying the suspended mixture slurry into a shape and drying it, and then roasting it to obtain a catalyst for synthesizing o-chlorobenzonitrile; the salts containing M, N and X respectively are chloride salts containing M, N and X respectively; the mass ratio of the vanadium pentoxide to the oxalic acid solution is 1:15; the mass percentage concentration of the oxalic acid solution is 10wt%; the multi-energy field comprises ultrasound, microwave and steady magnetic field; the ultrasound frequency is 80kHz and the power is 700W; the microwave frequency is 2.1GHz and the power is 900W; the steady magnetic field intensity is 0.5T; the drying temperature is 110°C and the time is 5h; the roasting temperature is 550°C and the time is 5h.

[0026] Example 2

[0027] A catalyst for synthesizing o-chlorobenzonitrile, using a molecular sieve as a carrier, wherein the active components include the following general formula components in terms of atomic number ratio: V 1.0 Fe a Se b M c N d X e O m , wherein: M is a rare earth element; N is a mixture of Cs and Mg in an atomic ratio of 1:1.2; X is a mixture of Ta, Ga, Ge, Os, Cr, and Sn in an atomic ratio of 1:0.35:0.15:0.015:1.2:0.15; a is 0.06; b is 0.02; c is 0.09; d is 0.1; e is 0.12; m is the number of oxygen atoms required to satisfy the valence of the element; the carrier molecular sieve in the catalyst is 50wt% by weight.

[0028] The rare earth element is a mixture of Pr, Gd and Dy in a molar ratio of 1:1.2:1.3; and the molecular sieve is ZSM-8 molecular sieve.

[0029] A preparation method of a catalyst for synthesizing o-chlorobenzonitrile comprises the following steps: adding vanadium pentoxide, ferric oxide, selenium dioxide and molecular sieve into an oxalic acid solution, stirring the mixture uniformly at 83°C, adding soluble salts containing M, N and X respectively into the solution, and using a multi-energy field to assist in treatment for 6 minutes to obtain a suspended mixture; spraying the suspended mixture slurry into a shape and drying it, and then roasting it to obtain a catalyst for synthesizing o-chlorobenzonitrile; the salts containing M, N and X respectively are nitrates containing M, N and X respectively; the mass ratio of the vanadium pentoxide to the oxalic acid solution is 1:17; the mass percentage concentration of the oxalic acid solution is 12wt%; the multi-energy field comprises ultrasound, microwave and steady magnetic field; the ultrasound frequency is 90kHz and the power is 800W; the microwave frequency is 2.2GHz and the power is 1000W; the steady magnetic field intensity is 1T; the drying temperature is 113°C and the time is 6h; the roasting temperature is 650°C and the time is 6h.

[0030] Example 3

[0031] A catalyst for synthesizing o-chlorobenzonitrile, using a molecular sieve as a carrier, wherein the active components include the following general formula components in terms of atomic number ratio: V 1.0 Fe a Se b M c N d X e O m , wherein: M is a rare earth element; N is a mixture of Cs and Mg in an atomic ratio of 1:1.5; X is a mixture of Ta, Ga, Ge, Os, Cr, and Sn in an atomic ratio of 1:0.4:0.2:0.02:1.5:0.2; a is 0.08; b is 0.025; c is 0.1; d is 0.12; e is 0.15; m is the number of oxygen atoms required to satisfy the valence of the element; the carrier molecular sieve in the catalyst is 55wt% by weight.

[0032] The rare earth element is a mixture of Pr, Gd and Dy in a molar ratio of 1:1.5:1.5; and the molecular sieve is SSZ-13 molecular sieve.

[0033] A preparation method of a catalyst for synthesizing o-chlorobenzonitrile, comprising the following steps: adding vanadium pentoxide, ferric oxide, selenium dioxide and molecular sieves to an oxalic acid solution, stirring evenly at 85°C, adding soluble salts containing M, N and X to the solution, and treating the solution with a multi-energy field for 8 minutes to obtain a suspended mixture; spraying the suspended mixture slurry into a dry form, and then calcining to obtain a catalyst for synthesizing o-chlorobenzonitrile; the salts containing M, N and X are respectively containing M , N, X chloride salts; the mass ratio of the vanadium pentoxide and the oxalic acid solution is 1:18; the mass percentage concentration of the oxalic acid solution is 13wt%; the multi-energy field includes ultrasound, microwave and steady magnetic field; the ultrasound frequency is 100kHz and the power is 950W; the microwave frequency is 2.3GHz and the power is 1300W; the steady magnetic field strength is 1.5T; the drying temperature is 115℃ and the time is 6.5h; the roasting temperature is 700℃ and the time is 7h.

[0034] Example 4

[0035] A catalyst for synthesizing o-chlorobenzonitrile, using a molecular sieve as a carrier, wherein the active components include the following general formula components in terms of atomic number ratio: V 1.0 Fe a Se b M c N d X e O m , wherein: M is a rare earth element; N is a mixture of Cs and Mg in an atomic ratio of 1:1.8; X is a mixture of Ta, Ga, Ge, Os, Cr, and Sn in an atomic ratio of 1:0.45:0.25:0.025:1.8:0.25; a is 0.09; b is 0.035; c is 0.11; d is 0.13; e is 0.18; m is the number of oxygen atoms required to satisfy the valence of the element; the carrier molecular sieve in the catalyst is 65wt% by weight.

[0036] The rare earth elements are a mixture of Pr, Gd and Dy in a molar ratio of 1:1.8:1.8; the molecular sieve is a mixture of MCM-48 molecular sieve, ZSM-8 molecular sieve and SSZ-13 molecular sieve in a mass ratio of 1:2:3.

[0037] A preparation method of a catalyst for synthesizing o-chlorobenzonitrile, comprising the following steps: adding vanadium pentoxide, ferric oxide, selenium dioxide and molecular sieves to an oxalic acid solution, stirring evenly at 88°C, adding soluble salts containing M, N and X respectively to the solution, using a multi-energy field to assist in treatment for 9 minutes to obtain a suspended mixture; spraying the suspended mixture slurry into a form of a dry product, and then calcining to obtain a catalyst for synthesizing o-chlorobenzonitrile; the salts containing M, N and X respectively are salts containing M , N, X nitrates; the mass ratio of the vanadium pentoxide and the oxalic acid solution is 1:19; the mass percentage concentration of the oxalic acid solution is 14wt%; the multi-energy field includes ultrasound, microwave and steady magnetic field; the ultrasound frequency is 110kHz, and the power is 1100W; the microwave frequency is 2.5GHz, and the power is 1400W; the steady magnetic field intensity is 2T; the drying temperature is 118°C, and the time is 7.5h; the calcination temperature is 830°C, and the time is 9h.

[0038] Example 5

[0039] A catalyst for synthesizing o-chlorobenzonitrile, using a molecular sieve as a carrier, wherein the active components include the following general formula components in terms of atomic number ratio: V 1.0 Fe a Se b M c N d X e O m , wherein: M is a rare earth element; N is a mixture of Cs and Mg in an atomic ratio of 1:2; X is a mixture of Ta, Ga, Ge, Os, Cr, and Sn in an atomic ratio of 1:0.5:0.3:0.03:2:0.3; a is 0.1; b is 0.04; c is 0.12; d is 0.15; e is 0.2; m is the number of oxygen atoms required to satisfy the valence of the element; the carrier molecular sieve in the catalyst is 70wt% by weight.

[0040] The rare earth element is a mixture of Pr, Gd and Dy in a molar ratio of 1:2:2; and the molecular sieve is MCM-48 molecular sieve.

[0041] A preparation method of a catalyst for synthesizing o-chlorobenzonitrile, comprising the following steps: adding vanadium pentoxide, ferric oxide, selenium dioxide and molecular sieves to an oxalic acid solution, stirring evenly at 90°C, adding soluble salts containing M, N and X to the solution, and performing multi-energy field assisted treatment for 10 minutes to obtain a suspended mixture; spraying the suspended mixture slurry into a dry form, and then calcining to obtain a catalyst for synthesizing o-chlorobenzonitrile; the salts containing M, N and X are respectively containing M , N, X chloride salts; the mass ratio of the vanadium pentoxide and the oxalic acid solution is 1:20; the mass percentage concentration of the oxalic acid solution is 15wt%; the multi-energy field includes ultrasound, microwave and steady magnetic field; the ultrasound frequency is 120kHz and the power is 1200W; the microwave frequency is 2.6GHz and the power is 1500W; the steady magnetic field intensity is 2.5T; the drying temperature is 120℃ and the time is 8h; the calcination temperature is 850℃ and the time is 10h.

[0042] Comparative Example 1

[0043] A catalyst for synthesizing o-chlorobenzonitrile and a preparation method thereof are substantially the same as those in Example 1, except that no nitrogen source is added.

[0044] Comparative Example 2

[0045] A catalyst for synthesizing o-chlorobenzonitrile and a preparation method thereof are substantially the same as those in Example 1, except that no X source is added.

[0046] In order to further illustrate the beneficial technical effects of the catalysts for synthesizing o-chlorobenzonitrile involved in each embodiment of the present invention, the performance of the catalysts for synthesizing o-chlorobenzonitrile involved in Examples 1-5 and Comparative Examples 1-2 was evaluated. The evaluation results are shown in Table 1. The evaluation method is as follows:

[0047] Process: o-chlorotoluene: ammonia: air = 1:4:20 (molar ratio), 50 g / kg catalyst load·hour, reaction temperature 425°C, reaction pressure 0.01 MPa. Statistics and calculation of o-chlorotoluene conversion, o-chlorobenzonitrile selectivity and o-chlorobenzonitrile yield.

[0048] Table 1

[0049] Test items o-Chlorotoluene conversion rate (%) Selectivity of o-chlorobenzonitrile (%) Yield of o-chlorobenzonitrile (%) Example 1 99.53 95.42 94.97 Example 2 99.75 95.63 95.39 Example 3 99.88 95.90 95.78 Example 4 99.92 96.11 96.03 Example 5 99.95 96.25 96.20 Comparative Example 1 97.87 95.06 93.04 Comparative Example 2 96.35 94.41 90.96

[0050] It can be seen from the data in Table 1 that the catalysts for synthesizing o-chlorobenzonitrile according to the embodiments of the present invention have better catalytic effects than the products of the comparative examples; the combined use of the N source and the X source is beneficial to improving the above performance.

[0051] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with this technology to understand the contents of the present invention and implement them accordingly. They cannot be used to limit the protection scope of the present invention. All equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A catalyst for synthesizing o-chlorobenzonitrile, characterized in that: With molecular sieve as carrier, the active components include the following general formula components in terms of atomic number ratio: V 1.0 Fe a Se b M c N d X e O m , wherein: M is a rare earth element; N is a mixture of Cs and Mg in an atomic ratio of 1:(1-2); X is a mixture of Ta, Ga, Ge, Os, Cr, and Sn in an atomic ratio of 1:(0.3-0.5):(0.1-0.3):(0.01-0.03):(1-2):(0.1-0.3); the value range of a is 0.05-0.1; the value range of b is 0.01-0.04; the value range of c is 0.08-0.12; the value range of d is 0.08-0.15; the value range of e is 0.1-0.2; m is the number of oxygen atoms required to satisfy the valence of the element; the carrier molecular sieve in the catalyst is 40-70wt% in weight percentage; the rare earth element is a mixture formed by mixing Pr, Gd, and Dy in a molar ratio of 1:(1-2):(1-2); The preparation method of the catalyst for synthesizing o-chlorobenzonitrile comprises the following steps: adding vanadium pentoxide, ferric oxide, selenium dioxide and molecular sieve into oxalic acid solution, stirring evenly at 80-90°C, adding soluble salts containing M, N and X respectively into the solution, and using multi-energy field auxiliary treatment for 5-10 minutes to obtain a suspended mixture; spraying the suspended mixture slurry into a shape and drying it, and then roasting it to obtain the catalyst for synthesizing o-chlorobenzonitrile; the multi-energy field comprises ultrasonic wave, microwave and steady magnetic field; the ultrasonic wave has a frequency of 80-120kHz and a power of 700-1200W; the microwave has a frequency of 2.1-2.6GHz and a power of 900-1500W; and the steady magnetic field has an intensity of 0.5-2.5T.

2. The catalyst for synthesizing o-chlorobenzonitrile according to claim 1, characterized in that The molecular sieve is at least one of MCM-48 molecular sieve, ZSM-8 molecular sieve and SSZ-13 molecular sieve.

3. The catalyst for synthesizing o-chlorobenzonitrile according to claim 1, characterized in that The salts containing M, N and X respectively are chloride salts or nitrate salts containing M, N and X respectively.

4. The catalyst for synthesizing o-chlorobenzonitrile according to claim 1, characterized in that The mass ratio of the vanadium pentoxide to the oxalic acid solution is 1:(15-20).

5. The catalyst for synthesizing o-chlorobenzonitrile according to claim 1, characterized in that The mass percentage concentration of the oxalic acid solution is 10-15wt%.

6. The catalyst for synthesizing o-chlorobenzonitrile according to claim 1, characterized in that The drying temperature is 110-120° C. and the drying time is 5-8 hours.

7. The catalyst for synthesizing o-chlorobenzonitrile according to claim 1, characterized in that The calcination temperature is 550-850° C. and the calcination time is 5-10 hours.