A process for the synthesis of clomazone

Abstract

The application discloses a synthesis process of chlorobenzoic acid, and the NiMo-Sb2O3 / TiO2-CeO2-MgO composite catalyst prepared by the method can better prepare ortho-chlorotoluene, has high selectivity and long service life, and has mild process conditions and small carbon deposition amount, so that the application has important significance for improving product quality, reducing production cost and promoting green development of the industry.

Description

TECHNICAL FIELD

[0001] The present application relates to a synthesis process of chlorobenzoitrile, belonging to the technical field of organic synthesis. BACKGROUND

[0002] Chlorobenzoitrile, as an important fine chemical intermediate, contains chlorine and cyano groups in its molecular structure, which endow it with unique chemical reactivity. It is widely used in the synthesis of antibacterial drugs, high-efficiency herbicides, disperse dyes, and liquid crystal materials. With the rapid development of downstream industries, the demand for purity and production capacity of chlorobenzoitrile continues to rise, prompting research and improvement of its synthesis process to become the focus of the industry.

[0003] Currently, the synthesis methods of chlorobenzoitrile mainly include the following categories: first, o-chloroaniline is converted into diazonium salt through diazotization reaction, and then undergoes Sandmeyer reaction with cuprous cyanide. Although this method has mild reaction conditions, it requires the use of highly toxic cyanide reagents, which poses serious safety hazards, and generates a large amount of waste liquid containing heavy metals, which is difficult to meet the requirements of modern green chemistry due to high environmental treatment costs; second, o-chlorobenzaldehyde reacts with hydroxylamine to form an oxime, which is then dehydrated by a dehydrating agent (such as acetic anhydride or phosphorus oxychloride) to form chlorobenzoitrile. This route is easy to obtain raw materials, but the dehydration step often accompanies side reactions, resulting in low product yield (usually less than 75%), and excessive use of dehydrating agents increases the difficulty of subsequent separation and purification and the amount of three wastes; third, o-chlorotoluene ammoxidation method, which uses o-chlorotoluene, ammonia, and oxygen as raw materials to convert into chlorobenzoitrile in one step under the action of a catalyst. Due to its high atom economy and low raw material cost, it has become the mainstream choice for industrial production.

[0004] However, the existing o-chlorotoluene ammoxidation process still has significant technical bottlenecks: the core catalyst is also in the process of continuous exploration, and existing catalysts include Ni-Fe double-site catalyst, RuO-Cl catalyst, LaCl3 / Al2O3 catalyst, etc., but most of them have uneven distribution of acidic sites, resulting in insufficient reaction selectivity (low selectivity of chlorobenzoitrile), easy occurrence of deep oxidation or dechlorination reaction to generate impurities such as benzonitrile, which not only reduces the utilization rate of raw materials but also increases the energy consumption of product purification; at the same time, the active components of some catalysts are easily deactivated due to carbon deposition or sintering, which seriously affects the continuity of production and increases the operating cost. In addition, the existing process requires strict control of reaction temperature and material ratio, and any fluctuation will lead to a sharp increase in by-products, further limiting the stability and economy of industrialized devices.

[0005] The present application aims to provide a synthesis process of chlorobenzoitrile with high selectivity, long-life catalyst, and mild process conditions, which is easy to control in industrialization. It is of great significance to improve product quality, reduce production cost, and promote the green development of the industry. SUMMARY

[0006] The object of the present application is to provide a synthesis process of chlorobenzoic acid. The NiMo-Sb2O3 / TiO2-CeO2-MgO composite catalyst prepared by the method can better prepare chlorobenzene, and has high conversion rate of chlorobenzene, good selectivity, small amount of carbon deposition and highest stability of active components.

[0007] A synthesis process of chlorobenzoic acid, characterized by comprising the following steps:

[0008] Step 1: preparing a NiMo-Sb2O3 / TiO2-CeO2-MgO composite catalyst, and the carrier is TiO2-CeO2-MgO;

[0009] Step 2: chlorobenzoic acid synthesis reaction: 60-80 parts of chlorobenzene are put into a reaction kettle, the temperature is adjusted to 210 degrees, and chlorobenzene starts to vaporize; the vaporized chlorobenzene, ammonia and air are introduced into a fluidized bed reactor provided with the above-mentioned 5-8 parts of NiMo-Sb2O3 / TiO2-CeO2-MgO composite catalyst at a volume ratio of 4:1:1, and the chlorobenzoic acid synthesis is carried out under the conditions of a reaction temperature of 430°C and a reaction pressure of 0.12 MPa, and the reaction time is 4 hours.

[0010] Step 3: product separation and purification: the reaction product is first cooled to room temperature by condensation, and a gas-liquid mixture is obtained; the gas-liquid mixture is subjected to gas-liquid separation to obtain a liquid crude product and unreacted gas; the unreacted gas can be recycled after recovery treatment; the liquid crude product is washed with 3% sodium hydroxide solution twice and deionized water once; the filtrate after filtration is subjected to vacuum rectification, and the fraction collected at a vacuum degree of 0.09 MPa and a temperature of 120°C is obtained to obtain chlorobenzoic acid product.

[0011] In the step 1, the specific preparation process of the catalyst is as follows:

[0012] a. Preparation of nickel solution: form a saturated solution of nickel nitrate in deionized water;

[0013] b. Preparation of molybdenum solution: form a saturated solution of ammonium molybdate in deionized water;

[0014] c. Preparation of antimony solution: weigh 0.1 mol of Sb2O3, add 500 mL of concentrated hydrochloric acid (mass fraction 37%), heat and reflux until completely dissolved to form SbCl3 solution, and dilute with deionized water to 1000 mL after cooling for standby;

[0015] d. TiO2-CeO2-MgO support with Ti:Ce:Mg molar ratio of 9:(0.3-0.5):(0.2-0.3) was prepared by co-precipitation method. First, the required amount of TiCl4, Ce(NO3)3.6H2O and Mg(NO3)2.6H2O were dissolved in ultrapure water to form a solution at room temperature. Next, excess ammonia was added to the solution and stirred vigorously until the pH value was 10. The resulting solution was stirred for another 3 hours and then left to stand for 24 hours. The precipitate was then filtered and washed with ultrapure water three times. The obtained filter cake was dried at 110°C overnight, and finally calcined at 450°C for 5 hours to obtain the TiO2-CeO2-MgO support, which was crushed through a 20-40 mesh sieve after natural cooling.

[0016] e. Mixed impregnation: the solutions obtained in steps a, b, and c were mixed in a volume ratio of 1:1:0.5, and the TiO2-CeO2-MgO support with a mass of 1 / 2 of the mixed solution was added. The mixture was stirred at room temperature for 2 hours to ensure uniform distribution of the active components on the surface of the support. Finally, the impregnated support was transferred to an oven and dried at 110°C overnight, and then calcined at 450°C for 5 hours. After natural cooling, the support was crushed through a 20-40 mesh sieve for use.

[0017] Advantages of the present application:

[0018] After years of research and practice, the research and development team invented a synthesis process of chlorobenzoic acid, which has a high selectivity, long-life catalyst, and a synthesis process of chlorobenzoic acid with mild process conditions and easy industrial control. It is of great significance to improve product quality, reduce production cost and promote green development of the industry. DETAILED DESCRIPTION

[0019] The embodiments of the present application are described in detail below, which are only used to explain the present application and cannot be understood as a limitation of the present application.

[0020] The specific embodiments of the present application are described as follows.

[0021] Preparation Example 1

[0022] A synthesis process of chlorobenzoic acid, characterized in that it comprises the following steps:

[0023] Step 1: Preparation of NiMo-Sb2O3 / TiO2-CeO2-MgO composite catalyst, the support is TiO2-CeO2-MgO;

[0024] Step 2: o-chloronitrile synthesis reaction: o-chlorotoluene 60 parts was put into the reaction kettle, the temperature was adjusted to 210 degrees, and o-chlorotoluene began to vaporize; the vaporized o-chlorotoluene, ammonia and air were introduced into the fluidized bed reactor containing the above-mentioned 8 parts of NiMo-Sb2O3 / TiO2-CeO2-MgO composite catalyst at a volume ratio of 4:1:1, and o-chloronitrile synthesis was carried out under the conditions of reaction temperature 430°C and reaction pressure 0.12 MPa, and the reaction time was 4 hours.

[0025] Step 3: product separation and purification: the reaction product was first cooled to room temperature by condensation to obtain a gas-liquid mixture; the gas-liquid mixture was subjected to gas-liquid separation to obtain liquid crude product and unreacted gas; the unreacted gas was recycled after recovery treatment; the liquid crude product was washed with 3% sodium hydroxide solution twice and deionized water once; the filtrate after filtration was subjected to vacuum rectification, and the fraction with a vacuum degree of 0.09 MPa and a temperature of 120°C was collected to obtain o-chloronitrile product.

[0026] The specific preparation process of the catalyst in step 1 is as follows:

[0027] a. Preparation of nickel solution: prepare a saturated solution of nickel nitrate in deionized water;

[0028] b. Preparation of molybdenum solution: prepare a saturated solution of ammonium molybdate in deionized water;

[0029] c. Preparation of antimony solution: weigh 0.1 mol of Sb2O3, add 500 mL of concentrated hydrochloric acid (mass fraction 37%), heat to reflux until completely dissolved to form SbCl3 solution, cool and dilute with deionized water to 1000 mL for standby;

[0030] d. TiO2-CeO2-MgO carrier with Ti:Ce:Mg molar ratio of 9:0.3:0.2 was prepared by co-precipitation method. First, the required amount of TiCl4, Ce(NO3)3·6H2O and Mg(NO3)2·6H2O was dissolved in ultrapure water to form a solution at room temperature. Then, excess ammonia water was added to the solution and stirred vigorously until the pH value was 10, and the obtained solution was stirred for 3 hours, and then left to stand for 24 hours. Then the precipitate was filtered and washed with ultrapure water for 3 times; the obtained filter cake was dried at 110°C overnight, and finally calcined at 450°C for 5 hours to obtain TiO2-CeO2-MgO carrier, which was crushed to 20-40 mesh sieve after natural cooling;

[0031] e. Mixed impregnation: the solution obtained in steps a, b, c is mixed in a volume ratio of 1:1:0.5, and TiO2-CeO2-MgO carrier in an amount of 1 / 2 of the mixed solution is added, and the mixture is stirred at room temperature for 2 hours to make the active components uniformly distributed and adsorbed on the surface of the carrier; finally, the impregnated carrier is transferred to an oven and dried at 110°C overnight, and then calcined at 450°C for 5 hours, and cooled naturally before being crushed to pass through a 20-40 mesh sieve for use.

[0032] Preparation Example 2

[0033] A synthesis process of chloroneb, characterized in that it comprises the following steps:

[0034] Step 1: Preparation of NiMo-Sb2O3 / TiO2-CeO2-MgO composite catalyst, with TiO2-CeO2-MgO as the carrier;

[0035] Step 2: Synthesis of chloroneb: 70 parts of o-chlorotoluene are placed in a reaction kettle, and the temperature is adjusted to 210°C, and the o-chlorotoluene starts to vaporize; the vaporized o-chlorotoluene, ammonia gas and air are introduced into a fluidized bed reactor containing 6 parts of the above-mentioned NiMo-Sb2O3 / TiO2-CeO2-MgO composite catalyst in a volume ratio of 4:1:1, and the synthesis of chloroneb is carried out under the conditions of a reaction temperature of 430°C and a reaction pressure of 0.12 MPa, and the reaction time is 4 hours.

[0036] Step 3: Product separation and purification: the reaction product is first cooled to room temperature by condensation, and a gas-liquid mixture is obtained; the gas-liquid mixture is subjected to gas-liquid separation to obtain a liquid crude product and unreacted gas; the unreacted gas is recycled after recovery treatment; the liquid crude product is washed with a 3% sodium hydroxide solution twice and deionized water once; the filtrate after filtration is subjected to vacuum rectification, and the fraction collected at a vacuum degree of 0.09 MPa and a temperature of 120°C is obtained to obtain the chloroneb product.

[0037] The specific preparation process of the catalyst in step 1 is as follows:

[0038] a. Preparation of nickel solution: prepare a saturated solution of nickel nitrate in deionized water;

[0039] b. Preparation of molybdenum solution: prepare a saturated solution of ammonium molybdate in deionized water;

[0040] c. Preparation of antimony solution: weigh 0.1 mol of Sb2O3, add 500 mL of concentrated hydrochloric acid (mass fraction 37%), heat and reflux until completely dissolved to form a SbCl3 solution, and then dilute with deionized water to 1000 mL for use;

[0041] d. TiO2-CeO2-MgO support with Ti:Ce:Mg molar ratio of 9:0.4:0.3 was prepared by co-precipitation method. First, TiCl4, Ce(NO3)3·6H2O and Mg(NO3)2·6H2O were dissolved in ultrapure water to form a solution at room temperature. Then, excess ammonia was added to the solution and stirred vigorously until the pH value was 10. The obtained solution was stirred for another 3 hours and then left to stand for 24 hours. Subsequently, the precipitate was filtered and washed with ultrapure water for 3 times. The obtained filter cake was dried at 110°C overnight, and finally calcined at 450°C for 5 hours to obtain TiO2-CeO2-MgO support, which was crushed through a 20-40 mesh sieve after natural cooling.

[0042] e. Mixed impregnation: the solutions obtained in steps a, b and c were mixed in a volume ratio of 1:1:0.5, and TiO2-CeO2-MgO support with mass of 1 / 2 of the mixed solution was added. The mixture was stirred at room temperature for 2 hours to ensure uniform distribution of the active components on the surface of the support. Finally, the impregnated support was transferred to an oven and dried at 110°C overnight, and then calcined at 450°C for 5 hours. After natural cooling, the support was crushed through a 20-40 mesh sieve for use.

[0043] Preparation Example 3

[0044] A synthesis process of chloroneb, characterized in that it comprises the following steps:

[0045] Step 1: Preparation of NiMo-Sb2O3 / TiO2-CeO2-MgO composite catalyst, with TiO2-CeO2-MgO as the support.

[0046] Step 2: Synthesis of chloroneb: 80 parts of o-chlorotoluene were placed in a reaction kettle, and the temperature was adjusted to 210°C. The o-chlorotoluene began to vaporize. The vaporized o-chlorotoluene, ammonia and air were introduced into a fluidized bed reactor containing 5 parts of the above NiMo-Sb2O3 / TiO2-CeO2-MgO composite catalyst at a volume ratio of 4:1:1. The synthesis of chloroneb was carried out at a reaction temperature of 430°C and a reaction pressure of 0.12 MPa, and the reaction time was 4 hours.

[0047] Step 3: Product separation and purification: the reaction product was first cooled to room temperature by condensation, obtaining a gas-liquid mixture. The gas-liquid mixture was subjected to gas-liquid separation to obtain liquid crude product and unreacted gas. The unreacted gas was recycled after recovery treatment. The liquid crude product was washed with 3% sodium hydroxide solution twice and deionized water once. The filtrate after filtration was subjected to vacuum rectification, and the fraction collected at a vacuum degree of 0.09 MPa and a temperature of 120°C was chloroneb product.

[0048] The specific preparation process of the catalyst in step 1 is as follows:

[0049] a. Nickel solution preparation: form a saturated solution of nickel nitrate in deionized water;

[0050] b. Molybdenum solution preparation: form a saturated solution of ammonium molybdate in deionized water;

[0051] c. Antimony solution preparation: weigh 0.1 mol of Sb2O3, add 500 mL of concentrated hydrochloric acid (mass fraction 37%), heat to reflux until completely dissolved to form a SbCl3 solution, and dilute with deionized water to 1000 mL after cooling for standby;

[0052] d. Ti:Ce:Mg molar ratio of 9:0.5:0.2 TiO2-CeO2-MgO support was prepared by co-precipitation method. First, the required amount of TiCl4, Ce(NO3)3·6H2O and Mg(NO3)2·6H2O were dissolved in ultrapure water to form a solution at room temperature. Then, excess ammonia water was added to the solution and stirred vigorously until the pH value was 10. The obtained solution was stirred for another 3 hours, and then left to stand for 24 hours. Subsequently, the precipitate was filtered and washed with ultrapure water for 3 times; the obtained filter cake was dried at 110°C overnight, and finally calcined at 450°C for 5 hours to obtain the TiO2-CeO2-MgO support, which was crushed through a 20-40 mesh sieve after natural cooling for standby;

[0053] e. Mixed impregnation: the solutions obtained in steps a, b, c were mixed in a volume ratio of 1:1:0.5, and the TiO2-CeO2-MgO support was added in an amount of 1 / 2 of the mass of the mixed solution. The mixture was stirred at room temperature for 2 hours to ensure uniform distribution of the active components on the surface of the support. Finally, the impregnated support was transferred to an oven and dried at 110°C overnight, and then calcined at 450°C for 5 hours. After natural cooling, the support was crushed through a 20-40 mesh sieve for standby.

[0054] Comparative Preparation Example 1

[0055] The same as Preparation Example 1, but NiMo / Al2O3 was selected as the catalyst to prepare o-chlorobenzonitrile.

[0056] Comprising the following steps:

[0057] Step 1: Preparation of NiMo / Al2O3 catalyst, the support is Al2O3;

[0058] Step 2: o-chlorobenzonitrile synthesis reaction: 60 parts of o-chlorotoluene were placed in a reaction kettle, and the temperature was adjusted to 210°C. The o-chlorotoluene began to vaporize. The vaporized o-chlorotoluene, ammonia gas and air were introduced into a fluidized bed reactor containing 8 parts of the above NiMo / Al2O3 composite catalyst in a volume ratio of 4:1:1. The o-chlorobenzonitrile synthesis was carried out at a reaction temperature of 430°C and a reaction pressure of 0.12 MPa, and the reaction time was 4 hours.

[0059] Step 3: Separation and purification of the product: The reaction product is first cooled to room temperature by condensation to obtain a gas-liquid mixture; the gas-liquid mixture is subjected to gas-liquid separation to obtain a liquid crude product and unreacted gas; the unreacted gas is recycled after recovery treatment; the liquid crude product is washed with 3% sodium hydroxide solution twice and deionized water once; the filtrate after filtration is subjected to vacuum rectification, and a fraction at a vacuum degree of 0.09 MPa and a temperature of 120°C is collected to obtain the o-chlorobenzonitrile product.

[0060] The specific preparation process of the catalyst in step 1 is as follows:

[0061] a. Preparation of nickel solution: form a saturated solution of nickel nitrate in deionized water;

[0062] b. Preparation of molybdenum solution: form a saturated solution of ammonium molybdate in deionized water;

[0063] c. Al2O3 is sieved through a 20-40 mesh sieve for use;

[0064] d. Mixed impregnation: mix the solutions obtained in steps a and b in a volume ratio of 1:1, add Al2O3 carrier with a mass of 1 / 2 of the mixed solution, and stir for 2 hours at room temperature to make the active components uniformly distributed and adsorbed on the surface of the carrier; finally, transfer the impregnated carrier to an oven, dry at 110°C overnight, then calcine at 450°C for 5 hours, and crush to pass through a 20-40 mesh sieve for use.

[0065] Comparative Preparation Example 2

[0066] The same as Preparation Example 1, but NiMo / TiO2 is selected as the catalyst for preparing o-chlorobenzonitrile.

[0067] A synthesis process of o-chlorobenzonitrile, characterized in that it comprises the following steps:

[0068] Step 1: Preparation of NiMo / TiO2 catalyst, with TiO2 as the carrier;

[0069] Step 2: o-chlorobenzonitrile synthesis reaction: place 60 parts of o-chlorotoluene into a reaction kettle, adjust the temperature to 210°C, and the o-chlorotoluene starts to vaporize; pass the vaporized o-chlorotoluene, ammonia and air into a fluidized bed reactor containing 8 parts of the above-mentioned NiMo / TiO2 catalyst in a volume ratio of 4:1:1, and carry out o-chlorobenzonitrile synthesis under the conditions of a reaction temperature of 430°C and a reaction pressure of 0.12 MPa, with a reaction time of 4 hours.

[0070] Step 3: Separation and purification of the product: The reaction product is first cooled to room temperature by condensation to obtain a gas-liquid mixture; the gas-liquid mixture is subjected to gas-liquid separation to obtain a liquid crude product and unreacted gas; the unreacted gas is recycled after recovery treatment; the liquid crude product is washed with 3% sodium hydroxide solution twice and deionized water once; the filtrate after filtration is subjected to vacuum rectification, and a fraction at a vacuum degree of 0.09 MPa and a temperature of 120°C is collected to obtain the o-chlorobenzonitrile product.

[0071] The specific preparation process of the catalyst in step 1 is as follows:

[0072] a. Preparation of nickel solution: a saturated solution of nickel nitrate in deionized water is prepared;

[0073] b. Preparation of molybdenum solution: a saturated solution of ammonium molybdate in deionized water is prepared;

[0074] c. TiCl4 is dissolved in ultrapure water to form a solution at room temperature. Then, excess ammonia water is added to the solution and stirred vigorously until the pH value is 10. The obtained solution is stirred for another 3 hours, and then left to stand for 24 hours. Subsequently, the precipitate is filtered and washed with ultrapure water for 3 times; the obtained filter cake is dried at 110°C overnight, and finally calcined at 450°C for 5 hours to obtain a TiO2 carrier, which is crushed to pass through a 20-40 mesh sieve for use;

[0075] e. Mixed impregnation: the solutions obtained in steps a and b are mixed in a volume ratio of 1:1, and the TiO2 carrier with a mass of 1 / 2 of the mixed solution is added. The mixture is stirred at room temperature for 2 hours to make the active components uniformly distributed and adsorbed on the surface of the carrier; finally, the impregnated carrier is transferred to an oven and dried at 110°C overnight, and then calcined at 450°C for 5 hours. After natural cooling, it is crushed to pass through a 20-40 mesh sieve for use.

[0076] Comparative Preparation Example 3

[0077] The same as Preparation Example 1, but NiMo-WO3 / TiO2 is selected as the catalyst for preparing o-chlorobenzonitrile.

[0078] A synthesis process of o-chlorobenzonitrile, characterized in that it comprises the following steps:

[0079] Step 1: Preparation of NiMo-WO3 / TiO2 composite catalyst, with TiO2 as the carrier;

[0080] Step 2: o-chloronitrile synthesis reaction: o-chlorotoluene 60 parts was put into a reaction kettle, the temperature was adjusted to 210 degrees, and o-chlorotoluene began to vaporize; the vaporized o-chlorotoluene, ammonia and air were introduced into the fluidized bed reactor containing the above-mentioned 8 parts of NiMo-WO3 / TiO2 composite catalyst at a volume ratio of 4:1:1, and o-chloronitrile synthesis was carried out under the conditions of reaction temperature 430℃ and reaction pressure 0.12MPa, and the reaction time was 4 hours.

[0081] Step 3: product separation and purification: the reaction product was first cooled to room temperature by condensation to obtain a gas-liquid mixture; the gas-liquid mixture was subjected to gas-liquid separation to obtain liquid crude product and unreacted gas; the unreacted gas was recycled after recovery treatment; the liquid crude product was washed with 3% sodium hydroxide solution twice and deionized water once; the filtrate after filtration was subjected to vacuum rectification, and the fraction with vacuum degree of 0.09MPa and temperature of 120℃ was collected to obtain o-chloronitrile product.

[0082] The specific preparation process of the catalyst in step 1 is as follows:

[0083] a. Preparation of nickel solution: prepare a saturated solution of nickel nitrate in deionized water;

[0084] b. Preparation of molybdenum solution: prepare a saturated solution of ammonium molybdate in deionized water;

[0085] c. Preparation of tungsten solution: weigh 0.1mol Na2WO4·2H2O, add 1000 mL deionized water and heat to dissolve;

[0086] d. Dissolve TiCl4 in ultrapure water to form a solution at room temperature. Then, add excess ammonia water to the solution and stir vigorously until the pH value is 10. Stir the resulting solution for another 3 hours, then let it stand for 24 hours. Then filter the precipitate and wash it with ultrapure water 3 times; dry the obtained filter cake at 110°C overnight, and finally calcine at 450°C for 5 hours to obtain TiO2 carrier, which is crushed to pass through a 20-40 mesh sieve after natural cooling;

[0087] e. Mixed impregnation: mix the solutions obtained in steps a, b and c in a volume ratio of 1:1:0.5, add TiO2 carrier with a mass of 1 / 2 of the mixed solution, and stir for 2 hours at room temperature to make the active components evenly distributed and adsorbed on the surface of the carrier; finally, transfer the impregnated carrier to an oven and dry at 110°C overnight, then calcine at 450°C for 5 hours, and crush to pass through a 20-40 mesh sieve after natural cooling.

[0088] Preparation Example 4

[0089] The same as Preparation Example 1, but NiMo-Sb2O3 / TiO2 was selected as the catalyst for preparing o-chloronitrile.

[0090] A synthesis process of chloroneb, characterized in comprising the following steps:

[0091] Step 1: preparing NiMo-Sb2O3 / TiO2 composite catalyst, the carrier is TiO2-CeO2-MgO;

[0092] Step 2: chloroneb synthesis reaction: 60 parts of o-chlorotoluene is put into a reaction kettle, the temperature is adjusted to 210 degrees, and the o-chlorotoluene starts to vaporize; the vaporized o-chlorotoluene, ammonia and air are passed into a fluidized bed reactor equipped with the above-mentioned 8 parts of NiMo-Sb2O3 / TiO2 composite catalyst at a volume ratio of 4:1:1, and the chloroneb synthesis is carried out under the conditions of a reaction temperature of 430°C and a reaction pressure of 0.12 MPa, and the reaction time is 4 hours.

[0093] Step 3: product separation and purification: the reaction product is first cooled to room temperature by condensation, and a gas-liquid mixture is obtained; the gas-liquid mixture is subjected to gas-liquid separation to obtain a liquid crude product and unreacted gas; the unreacted gas can be recycled after recovery treatment; the liquid crude product is washed with 3% sodium hydroxide solution twice and deionized water once; the filtrate after filtration is subjected to vacuum rectification, and the fraction collected at a vacuum degree of 0.09 MPa and a temperature of 120°C is obtained to obtain the chloroneb product.

[0094] The specific preparation process of the catalyst in step 1 is as follows:

[0095] a. Preparation of nickel solution: prepare a saturated solution of nickel nitrate in deionized water;

[0096] b. Preparation of molybdenum solution: prepare a saturated solution of ammonium molybdate in deionized water;

[0097] c. Preparation of antimony solution: weigh 0.1 mol of Sb2O3, add 500 mL of concentrated hydrochloric acid (mass fraction 37%), heat to reflux until completely dissolved to form SbCl3 solution, cool and dilute with deionized water to 1000 mL for standby;

[0098] d. Dissolve TiCl4 in ultrapure water to form a solution at room temperature. Then, add excess ammonia water to the solution and stir vigorously until the pH value is 10, stir the obtained solution for 3 hours, and then stand for 24 hours. Then filter the precipitate and wash it with ultrapure water for 3 times; dry the obtained filter cake at 110°C overnight, and finally calcine at 450°C for 5 hours to obtain the TiO2 carrier, which is crushed to pass through a 20-40 mesh sieve for standby;

[0099] e. Mixed impregnation: the solution obtained in steps a, b, c is mixed in a volume ratio of 1:1:0.5, and TiO2 carrier with a mass of 1 / 2 of the mixed solution is added, and the mixture is stirred at room temperature for 2 hours to make the active components uniformly distributed and adsorbed on the surface of the carrier; finally, the impregnated carrier is transferred to an oven and dried at 110°C overnight, and then calcined at 450°C for 5 hours, and then naturally cooled and crushed to pass through a 20-40 mesh sieve for use.

[0100] Preparation Example 5

[0101] The same as Preparation Example 1, but NiMo-Sb2O3 / TiO2-CeO2 is selected as the catalyst for preparing o-chloronitrile.

[0102] A synthesis process of o-chloronitrile, characterized in that it comprises the following steps:

[0103] Step 1: preparing NiMo-Sb2O3 / TiO2-CeO2 composite catalyst, with TiO2-CeO2 as the carrier;

[0104] Step 2: o-chloronitrile synthesis reaction: 60 parts of o-chlorotoluene are put into a reaction kettle, and the temperature is adjusted to 210 degrees; the vaporized o-chlorotoluene, ammonia and air are introduced into a fluidized bed reactor containing 8 parts of the above-mentioned NiMo-Sb2O3 / TiO2-CeO2 composite catalyst in a volume ratio of 4:1:1, and o-chloronitrile synthesis is carried out under the conditions of a reaction temperature of 430°C and a reaction pressure of 0.12 MPa, and the reaction time is 4 hours.

[0105] Step 3: product separation and purification: the reaction product is first cooled to room temperature by condensation to obtain a gas-liquid mixture; the gas-liquid mixture is subjected to gas-liquid separation to obtain a liquid crude product and unreacted gas; the unreacted gas is recycled after recovery treatment; the liquid crude product is washed with a 3% sodium hydroxide solution twice and deionized water once; the filtrate after filtration is subjected to vacuum rectification, and the fraction collected at a vacuum degree of 0.09 MPa and a temperature of 120°C is o-chloronitrile product.

[0106] The specific preparation process of the catalyst in step 1 is as follows:

[0107] a. Preparation of nickel solution: prepare a saturated solution of nickel nitrate in deionized water;

[0108] b. Preparation of molybdenum solution: prepare a saturated solution of ammonium molybdate in deionized water;

[0109] c. Preparation of antimony solution: weigh 0.1 mol of Sb2O3, add 500 mL of concentrated hydrochloric acid (mass fraction 37%), heat and reflux until completely dissolved to form a SbCl3 solution, and then dilute with deionized water to 1000 mL for standby use;

[0110] d. TiO2-CeO2 support with Ti:Ce molar ratio of 9:0.3 was prepared by co-precipitation method. First, the required amount of TiCl4, Ce(NO3)3.6H2O was dissolved in ultrapure water to form a solution at room temperature. Then, excess ammonia was added to the solution and stirred vigorously until the pH value was 10, and the resulting solution was stirred for another 3 hours, and then left to stand for 24 hours. Subsequently, the precipitate was filtered and washed with ultrapure water for 3 times; the obtained filter cake was dried at 110°C overnight, and finally calcined at 450°C for 5 hours to obtain the TiO2-CeO2 support, which was crushed through a 20-40 mesh sieve after natural cooling;

[0111] e. Mixed impregnation: the solutions obtained in steps a, b, c were mixed in a volume ratio of 1:1:0.5, and the TiO2-CeO2 support with a mass of 1 / 2 of the mixed solution was added, stirred and impregnated at room temperature for 2 hours to make the active components evenly distributed and adsorbed on the surface of the support; finally, the impregnated support was transferred to an oven and dried at 110°C overnight, and then calcined at 450°C for 5 hours, and crushed through a 20-40 mesh sieve after natural cooling.

[0112] Preparation Example 6

[0113] The same as Preparation Example 1, but NiMo-Sb2O3 / TiO2-CeO2-CuO was selected as the catalyst for preparing o-chlorobenzonitrile.

[0114] A process for synthesizing o-chlorobenzonitrile, characterized in that it comprises the following steps:

[0115] Step 1: preparing NiMo-Sb2O3 / TiO2-CeO2-CuO composite catalyst, the support is TiO2-CeO2-CuO;

[0116] Step 2: o-chlorobenzonitrile synthesis reaction: 60 parts of o-chlorotoluene were placed in a reaction kettle, the temperature was adjusted to 210°C, and the o-chlorotoluene began to vaporize; the vaporized o-chlorotoluene, ammonia and air were introduced into a fluidized bed reactor containing 8 parts of the above NiMo-Sb2O3 / TiO2-CeO2-CuO composite catalyst at a volume ratio of 4:1:1, and the o-chlorobenzonitrile synthesis was carried out under the conditions of reaction temperature 430°C and reaction pressure 0.12 MPa, and the reaction time was 4 hours.

[0117] Step 3: Separation and purification of the product: The reaction product was first cooled to room temperature by condensation to obtain a gas-liquid mixture; the gas-liquid mixture was subjected to gas-liquid separation to obtain a liquid crude product and unreacted gas; the unreacted gas was recycled after recovery treatment; the liquid crude product was washed with 3% sodium hydroxide solution twice and deionized water once; the filtrate after filtration was subjected to vacuum rectification, and the fraction at a vacuum degree of 0.09 MPa and a temperature of 120°C was collected to obtain the o-chloronitrile product.

[0118] The specific preparation process of the catalyst in step 1 is as follows:

[0119] a. Preparation of nickel solution: a saturated solution of nickel nitrate in deionized water was prepared;

[0120] b. Preparation of molybdenum solution: a saturated solution of ammonium molybdate in deionized water was prepared;

[0121] c. Preparation of antimony solution: 0.1 mol of Sb2O3 was weighed, 500 mL of concentrated hydrochloric acid (mass fraction 37%) was added, and heating reflux was performed until complete dissolution to form an SbCl3 solution. After cooling, deionized water was added to dilute the solution to 1000 mL for standby use;

[0122] d. A TiO2-CeO2-CuO carrier with a Ti:Ce:Cu molar ratio of 9:0.3:0.2 was prepared by a coprecipitation method. First, the required amounts of TiCl4, Ce(NO3)3·6H2O and CuSO4·5H2O were dissolved in ultrapure water to form a solution at room temperature. Then, excess ammonia water was added to the solution and stirred vigorously until the pH value was 10. The obtained solution was stirred for another 3 hours, and then left to stand for 24 hours. Subsequently, the precipitate was filtered and washed with ultrapure water for 3 times; the obtained filter cake was dried at 110°C overnight, and finally calcined at 450°C for 5 hours to obtain the TiO2-CeO2-CuO carrier, which was crushed through a 20-40 mesh sieve after natural cooling for standby use;

[0123] e. Mixed impregnation: the solutions obtained in steps a, b and c were mixed in a volume ratio of 1:1:0.5, and the TiO2-CeO2-CuO carrier with a mass of 1 / 2 of the mixed solution was added. The mixture was stirred at room temperature for 2 hours to make the active components uniformly distributed and adsorbed on the surface of the carrier; finally, the impregnated carrier was transferred to an oven and dried at 110°C overnight, and then calcined at 450°C for 5 hours. After natural cooling, the carrier was crushed through a 20-40 mesh sieve for standby use.

[0124] Test Example 1

[0125] The conversion rate of o-chlorotoluene in Preparation Example 1-3 and Comparative Preparation Example 1-6 was determined: 1 mL of the condensed liquid crude product was sampled from the gas-liquid mixture at the reactor outlet, 0.5 mL of n-dodecane (an internal standard, with a known concentration) was added, the mixture was diluted with ethyl acetate to 10 mL, and after uniform shaking, the upper clear liquid was separated and passed through a 0.22 μm organic phase filter membrane for gas chromatography detection, using a DB-5 chromatographic column; in order to ensure complete separation of o-chlorotoluene, o-chlorobenzonitrile and by-products, the gas chromatography detection conditions were as follows: initial temperature 80°C, holding for 2 minutes; temperature increased to 200°C at a rate of 10°C / min, holding for 5 minutes; nitrogen (purity ≥ 99.999%) was selected, flow rate 1.0 mL / min, split ratio 20:1, n-dodecane was used as an internal standard, and the amount of o-chlorotoluene was calculated by comparing the peak area of o-chlorotoluene with that of the internal standard. The conversion rate (X) of o-chlorotoluene was calculated according to the following formula: Each test example was measured three times, and the results are shown below:

[0126] Table 1 Conversion rate of o-chlorotoluene

[0127] ;

[0128] The results show that the conversion rates of o-chlorotoluene prepared by the methods of Preparation Example 1-3 and Comparative Preparation Example 3-6 are all high, and the conversion rate of o-chlorotoluene prepared by Preparation Example 1-3 is the highest, all greater than 90%.

[0129] Test Example 2

[0130] Preparation Example 1-3 and Comparative Preparation Example 1-6: The liquid crude product after condensation was sampled from the gas-liquid mixture at the outlet of the reactor, 2 mL, 0.5 g of anhydrous sodium sulfate was added, shaken for 1 min to remove water, 1 mL of 2,4-dichlorotoluene solution with a concentration of 0.1 mg / mL was added as an internal standard, and shaken for 5 min; 3 mL of acetonitrile was added to the above mixture, ultrasonic extraction was performed for 15 min (power 300 W, temperature 30°C), and then centrifugation was performed at 8000 r / min for 10 min, and the upper organic phase was taken. The extraction operation was repeated once, and the upper organic phases of the two times were combined, diluted with acetonitrile to 10 mL, filtered through a 0.22 μm organic phase filter membrane, and the filtrate was subjected to gas chromatography-mass spectrometry detection; the preparation of the standard solution of o-chlorobenzonitrile, o-chlorobenzaldehyde, and cyanophenyl standard and the drawing of the standard curve were performed synchronously, and 2,4-dichlorotoluene was used as an internal standard solution; the detection conditions of the chromatography were as follows: initial temperature 80°C, holding for 2 min; the temperature was increased to 200°C at a rate of 10°C / min, holding for 5 min; the characteristic ions (m / z) of each target and the internal standard were selected according to the mass spectrum, the sample was analyzed according to the above GC-MS conditions, the concentrations of o-chlorobenzonitrile (C1), o-chlorobenzaldehyde (C2), and cyanophenyl (C3) in the sample were obtained according to the standard curve, the mass of each substance was calculated combined with the constant volume, and the molar mass of each substance was converted into the molar amount (n1, n2, n3). The selectivity (S) of o-chlorotoluene was calculated according to the following formula: ; each test example was determined three times, and the results are as follows:

[0131] Table 2 Determination of the selectivity of o-chlorotoluene

[0132] ;

[0133] The results show that the selectivity of o-chlorotoluene prepared by the methods of Preparation Example 1-3 and Comparative Preparation Example 4-6 is relatively high, and the selectivity of o-chlorotoluene prepared by Preparation Example 1-3 is the highest, which is greater than 95%.

[0134] Test Example 3

[0135] Preparation Example 1-3 and Comparative Preparation Example 1-6: The mass change of the catalyst in the process of programmed temperature was measured rapidly by using the muffle furnace calcination method, and the carbon deposition amount of the catalyst after 150 hours of continuous reaction was calculated. After washing and drying, the catalyst was weighed (m1), and then placed in a porcelain crucible with a constant weight. The crucible was placed in a muffle furnace, and the temperature was increased to 700°C at a rate of 5°C / min under an air atmosphere, and held for 3 hours (to ensure that the carbon deposition was completely burned). After cooling to room temperature, the mass of the residual catalyst (m2) was measured. The carbon deposition amount (%) was calculated according to the following formula: (%) = (m1- m2) / m1× 100%; each test example was determined three times, and the results are as follows:

[0136] Table 3. Determination of carbon deposition in o-chlorotoluene

[0137] ;

[0138] The results showed that the carbon deposits prepared by the methods in Preparation Examples 1-3 and Comparative Preparation Examples 5-6 were relatively low, with Preparation Example 1-3 producing the smallest amount of carbon deposit, less than 3%.

[0139] Test Example 4

[0140] Stability determination of active components in Preparation Examples 1-3 and Comparative Preparation Examples 1-6: The continuous reaction life used in each group was tested, and the endpoint was set when the conversion of o-chlorotoluene decreased to 80% of the initial value. The cumulative run time was calculated. The results are shown below:

[0141] Table 4. Stability determination of o-chlorotoluene

[0142]

[0143] The results showed that the o-chlorotoluene prepared by the methods of Preparation Examples 1-3 and Comparative Preparation Examples 5-6 had high stability, with Preparation Example 1-3 showing the highest stability, exceeding 300 hours.

[0144] The results showed that the NiMo-Sb₂O₃ / TiO₂-CeO₂-MgO composite catalyst had the highest catalytic efficiency. The o-chlorotoluene prepared by this method exhibited high conversion rate, good selectivity, low carbon deposition, and the highest stability of the active component. We hypothesize that NiMo provides active sites for hydrogenation, while Sb₂O₃ regulates NH₃ adsorption and inhibits polychlorinated byproducts, increasing oxygen vacancies at the Sb-O-Ti interface, promoting reactant activation, and inhibiting deep oxidation. TiO₂, as a support, has a certain effect on promoting the oxidation of chloroaromatics. The introduction of Ce can improve the dispersion of the active component. When Ce and Mg are introduced simultaneously as basic promoters, the effect on improving the dispersion of the active component is better than adding elements alone, and it can better balance the carbon deposition and deactivation problem caused by acid-base imbalance.

[0145] It should be noted that the above description is only a preferred embodiment of the present invention.

[0146] Any modifications made according to the concept of this invention that produce functional effects that do not exceed the spirit covered by the specification should be within the scope of this invention.

[0147] In the description of the specification, reference to "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" means that a particular feature, structure, material, or characteristic being described is included in at least one embodiment or example of the application. The appearances of the above expressions in various places in the specification are not necessarily referring to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples.

[0148] Although embodiments of the application have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions, and alterations can be made hereto without departing from the spirit and scope of the application, which is defined by the following claims and their equivalents.

Claims

1. A process for synthesizing o-chlorobenzonitrile, characterized in that, Includes the following steps: Step 1: Prepare NiMo-Sb2O3 / TiO2-CeO2-MgO composite catalyst, wherein the catalyst support is TiO2-CeO2-MgO; Step 1 involves the preparation of the NiMo-Sb2O3 / TiO2-CeO2-MgO composite catalyst, which includes: a. Preparation of nickel solution: Dissolve nickel nitrate in deionized water to form a saturated solution; b. Preparation of molybdenum solution: Dissolve ammonium molybdate in deionized water to form a saturated solution; c. Preparation of antimony solution: Weigh 0.1 mol Sb2O3, add 500 mL of 37% concentrated hydrochloric acid, heat under reflux until completely dissolved to form SbCl3 solution, cool and dilute with deionized water to 1000 mL; d. Support preparation: TiO2-CeO2-MgO support was prepared by co-precipitation method, wherein the molar ratio of Ti:Ce:Mg was 9:(0.3-0.5):(0.2-0.3); e. Mixed impregnation: Mix the solutions from steps a, b, and c in a volume ratio of 1:1:0.5, add TiO2-CeO2-MgO support accounting for 1 / 2 of the mass of the mixture, stir and impregnate at room temperature for 2 hours, dry at 110℃ overnight, calcine at 450℃ for 5 hours, and pulverize through a 20-40 mesh sieve; Step 2: Synthesis reaction of o-chlorobenzonitrile: 60-80 parts of o-chlorotoluene are placed in a reactor and the temperature is adjusted to 210℃ to vaporize the o-chlorotoluene; the vaporized o-chlorotoluene, ammonia and air are introduced into a fluidized bed reactor containing 5-8 parts of the NiMo-Sb2O3 / TiO2-CeO2-MgO composite catalyst at a volume ratio of 4:1:1, and the reaction is carried out for 4 hours at a reaction temperature of 430℃ and a reaction pressure of 0.12MPa; Step 3: Product separation and purification: The reaction product is condensed to room temperature to obtain a gas-liquid mixture. After gas-liquid separation, the crude liquid product is taken and washed successively with sodium hydroxide solution and deionized water. After filtration, the filtrate is subjected to vacuum distillation to obtain o-chlorobenzonitrile product.

2. The synthesis process according to claim 1, characterized in that, The liquid crude product obtained in the product separation and purification process in step 3 needs to be washed twice with a 3% sodium hydroxide solution and then once with deionized water; the vacuum degree of the vacuum distillation is 0.09 MPa, and the o-chlorobenzonitrile product can be obtained by collecting the fraction at 120°C.

3. The synthesis process according to any one of claims 1-2, characterized in that, The specific preparation process of TiO2-CeO2-MgO support is as follows: TiCl4, Ce(NO3)3・6H2O and Mg(NO3)2・6H2O are dissolved in ultrapure water, excess ammonia is added at room temperature and stirred until pH=10, stirring is continued for 3 hours and then allowed to stand for 24 hours. The precipitate is filtered, washed 3 times with ultrapure water, dried at 110℃ overnight, calcined at 450℃ for 5 hours, and then pulverized through a 20-40 mesh sieve.

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