Method for preparing ketoxime compound

Abstract

The invention relates to a method for preparing ketoxime compounds, which comprises the following steps: contacting a ketone compound, a catalyst and an ammonia source in a liquid-phase medium to obtain a reaction mixture, and releasing ammonia gas from the ammonia source; the catalyst comprises a carrier and active metal loaded on the carrier, the active metal comprises IB group metal and VIII group metal, and the carrier comprises a titanium silicalite molecular sieve; introducing the first raw material gas and the second raw material gas into the reaction mixture to be in contact with a catalyst for in-situ reaction to obtain a reaction product containing the ketoxime compound; wherein the first feed gas comprises hydrogen, and the second feed gas comprises oxygen. According to the method, hydrogen and oxygen are used as reaction raw material gases, ketoxime is prepared through in-situ ammoximation of ketone compounds, the safety problem caused by production, use, storage and transportation of hydrogen peroxide is solved, and the method is simple in process and environmentally friendly.

Description

Technical Field

[0001] This disclosure relates to the field of ketoxime preparation, and more specifically, to a method for preparing ketoxime compounds. Background Technology

[0002] Cyclohexanone oxime is an organic intermediate in the production of caprolactam. Caprolactam, as a monomer for basic chemicals such as nylon-6 fibers, nylon-6 engineering plastics, and films, has seen enormous consumption in recent years due to the development of the chemical fiber industry, leading to a corresponding increase in the demand for cyclohexanone oxime. Currently, there are two main industrial methods: the hydroxylamine oxime process and the ammonium oxime process. The former requires establishing a complex hydroxylamine salt production line, then using the obtained hydroxylamine salt to oximeize cyclohexanone to generate cyclohexanone oxime. This process involves a long production flow, large equipment investment, complex operation and control, and high production costs. Later, Eni of Italy and the Petrochemical Research Institute of China Petroleum & Chemical Corporation successively developed the ammoniation process for cyclohexanone. For example, patents US 4745221 and CN200810227656.1 disclose a process using TS-1 as a catalyst and H2O2 as an oxygen source, where cyclohexanone undergoes ammoniation to produce cyclohexanone oxime under normal pressure and at 60℃~80℃. This process requires a hydrogen peroxide production unit. Processes for producing cyclohexanone oxime from other types of cyclic ketones (such as cyclopentanone) also have similar problems, namely, the need to use hydrogen peroxide for the reaction, thus also requiring a hydrogen peroxide production unit.

[0003] Currently, the industrial production technology for hydrogen peroxide is the anthraquinone auto-oxidation method. Using anthraquinone as a carrier, crude hydrogen peroxide is obtained through catalytic hydrogenation and auto-oxidation. After extraction and purification, a hydrogen peroxide product with a mass fraction of 27.5% or 35% is obtained. This product is then transported to an ammonia oxime production unit for further reactions. However, high-concentration hydrogen peroxide is unstable and easily decomposes, and its storage and transportation incur costs and safety hazards. Summary of the Invention

[0004] The purpose of this disclosure is to provide a method for preparing ketoxime compounds, using hydrogen and oxygen as reaction raw materials, which can carry out the reaction of ketone compounds to ketoximes in situ by ammonoximation, eliminating the safety problems caused by the production, use and storage of hydrogen peroxide, and the process is simple and environmentally friendly.

[0005] To achieve the above objectives, this disclosure provides a method for preparing ketoxime compounds, comprising the following steps: A ketone compound, a catalyst, and an ammonia source are contacted in a liquid medium to obtain a reaction mixture, wherein the ammonia source releases ammonia gas; the catalyst includes a support and an active metal supported on the support; the active metal includes Group IB metals and Group VIII metals; and the support includes a titanium silicate molecular sieve. A first feed gas and a second feed gas are introduced into the reaction mixture and contacted with a catalyst to carry out an in-situ reaction, yielding a reaction product containing ketoxime compounds; wherein the first feed gas includes hydrogen and the second feed gas includes oxygen.

[0006] Optionally, the volume fraction of hydrogen in the first feed gas is less than 15% by volume, preferably less than 10% by volume. The oxygen volume fraction in the second raw material gas is greater than 5% by volume, preferably greater than 7% by volume. More preferably, the molar ratio of hydrogen to oxygen is 0.01 to 10:1, more preferably 0.16 to 5:1.

[0007] Optionally, the first raw material gas further includes a first dilution gas; preferably, the volume fraction of the first dilution gas in the first raw material gas is 50% or more, more preferably 55% or more, and even more preferably 60% or more. The second raw material gas also includes a second dilution gas; preferably, the volume fraction of the second dilution gas in the second raw material gas is 50% or more, more preferably 55% or more, and even more preferably 60% or more. Optionally, the first diluting gas and the second diluting gas are each independently selected from one or more of nitrogen, carbon dioxide, argon and helium.

[0008] Optionally, the ketone compound is selected from one or more of cyclopentanone, cyclohexanone, cycloheptanone, and cyclooctanone; more preferably, cyclohexanone.

[0009] Optionally, the Group IB metal is selected from one or more of gold, silver, and copper; the Group VIII metal is selected from one or more of ruthenium, palladium, platinum, rhodium, cobalt, nickel, and iridium; preferably, the active metal of the catalyst includes gold and palladium; more preferably, the molar ratio of gold to palladium in the catalyst is 1:0.01~20, more preferably 1:0.5~10; preferably, based on the total weight of the catalyst, the content of the active metal is 0.01~20% by weight, more preferably 0.01~5% by weight. The carrier is a titanium-silicon molecular sieve; preferably, the molar ratio of silicon to titanium in the titanium-silicon molecular sieve is 10~300:1, more preferably 20~200:1.

[0010] Optionally, the ammonia source is selected from one or more of ammonia water, ammonium chloride, ammonium bicarbonate and ammonium carbonate; preferably, ammonium bicarbonate.

[0011] Optionally, the liquid medium is selected from one or more of water, methanol, ethanol, isopropanol, 1,4-dioxane and tert-butanol; preferably tert-butanol and optionally water, and more preferably, the volume ratio of water to tert-butanol is 0 to 20:1.

[0012] Optionally, the reaction conditions for the in-situ reaction include: a reaction temperature of 0~300℃, a reaction pressure of 1.0~20.0 MPa, and a reaction time of 0.5~10h; preferably, the reaction temperature is 20~250℃, the reaction pressure is 3.0~10.0 MPa, and the reaction time is 1~5h.

[0013] Optionally, the method further includes heating the reaction system to the reaction temperature at a heating rate of 0.1~10℃ / min, preferably 0.5~5℃ / min.

[0014] Optionally, the weight ratio of the ketone compound to the catalyst is 1 to 100:1, preferably 15 to 50:1; The weight ratio of the liquid phase reaction medium to the catalyst is 10~2000:1, preferably 1000~2000:1; The weight ratio of the ammonia source to the catalyst in the liquid reaction medium is 10~1000:1, preferably 10~500:1.

[0015] Through the above technical solution, this disclosure provides a method for preparing ketoxime compounds. This method uses hydrogen and oxygen as reactant gases, which react directly with ketone compounds and an ammonia source in situ under the action of a catalyst to generate ketoxime compounds. This method has extremely high atom economy, and the only byproduct of the reaction of hydrogen and oxygen is water, resulting in good environmental benefits. Compared with the industrial automatic oxidation method of anthraquinone, the method provided by this disclosure greatly simplifies the process flow and eliminates the use of anthraquinone and organic solvents, making it more in line with the requirements of green chemistry and clean production. This disclosure uses hydrogen and oxygen and ketone compounds as reactant gases to carry out the ammonoximation reaction in situ, eliminating the safety problems caused by the production, use, storage and transportation of hydrogen peroxide. The process is simple, environmentally friendly, and does not require a hydrogen peroxide production unit, which can greatly simplify the process flow and reduce costs.

[0016] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0017] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof.

[0018] Figure 1 This is a flowchart of a method for preparing ketoxime compounds provided in this disclosure; Figure 2 This is a laboratory apparatus for the preparation of ketoxime compounds provided in this disclosure.

[0019] Figure Labels 1-Hydrogen cylinder; 2-Oxygen cylinder; 3-Pressure gauge; 4-Inlet; 5-Pressure gauge; 6-Electric stir bar; 7-Thermocouple; 8-Tail gas discharge valve; 9-Inner liner; 10-Condensate; 11-Condensate; 12-Condensation box; 13-Gas chromatograph; 14-Computer. Detailed Implementation

[0020] The following provides a detailed description of specific embodiments of this disclosure. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit this disclosure. The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values; these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0021] The following provides a detailed description of specific embodiments of this disclosure. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit this disclosure.

[0022] This disclosure provides a method for preparing ketoxime compounds, comprising the following steps: A ketone compound, a catalyst, and an ammonia source are contacted in a liquid medium to obtain a reaction mixture, wherein the ammonia source releases ammonia gas; the catalyst includes a support and an active metal supported on the support; the active metal includes Group IB metals and Group VIII metals; and the support includes a titanium silicate molecular sieve. A first feed gas and a second feed gas are introduced into the reaction mixture and contacted with a catalyst to carry out an in-situ reaction, yielding a reaction product containing ketoxime compounds; wherein the first feed gas includes hydrogen and the second feed gas includes oxygen.

[0023] This disclosure provides a method for preparing ketoxime compounds. The method uses hydrogen and oxygen as reactant gases, and under the action of a metal catalyst, directly and in situ reacts with ketone compounds and an ammonia source to generate ketoximes. This method boasts extremely high atom economy, and the only byproduct of the hydrogen and oxygen reaction is water, resulting in a favorable environmental effect. Compared to the industrial auto-oxidation method for anthraquinone, the method provided in this disclosure significantly simplifies the process flow and eliminates the use of anthraquinone and organic solvents, thus better meeting the requirements of green chemistry and clean production. This disclosure uses hydrogen, oxygen, and ketone compounds as reactant gases to carry out an in-situ ammoniation reaction, eliminating the safety issues associated with the production, use, storage, and transportation of hydrogen peroxide. The process is simple, environmentally friendly, and requires no supporting hydrogen peroxide production equipment, significantly simplifying the process flow and reducing costs.

[0024] In this disclosure, "ammonia source" refers to a substance that can provide ammonia gas.

[0025] In this disclosure, hydrogen and oxygen are further mixed with a dilution gas, and the hydrogen and oxygen react in proportions outside the flammable range to generate hydrogen peroxide by introducing the dilution gas. The dilution gas is an inert gas that does not participate in the reaction.

[0026] In one embodiment, the volume fraction of hydrogen in the first raw material gas is less than 15% by volume, preferably less than 10% by volume; the volume fraction of oxygen in the second raw material gas is greater than 5% by volume, preferably greater than 7% by volume. In the method provided by this disclosure, by controlling the volume fractions of hydrogen in the first raw material gas and oxygen in the second raw material gas within the range described in the above embodiment, it is possible to ensure that the gases are outside the flammable range and to improve the formation effect of ketoxime compounds.

[0027] In a preferred embodiment, the molar ratio of hydrogen to oxygen is 0.01 to 2.5:1, including but not limited to 0.01:1, 0.5:1, 1:1, 1.5:1, 2:1, and 2.5:1; preferably 0.165 to 5:1, including but not limited to 0.165:1, 1:1, 1.5:1, 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 4.5:1, and 5:1. When the molar ratio of hydrogen to oxygen in the in-situ reaction is within the range provided in this embodiment, especially within the preferred range, better reaction results can be obtained.

[0028] In one specific embodiment, the first raw material gas further includes a first diluent gas; the second raw material gas further includes a second diluent gas; the first diluent gas and the second diluent gas are each independently selected from one or more of nitrogen, carbon dioxide, argon, and helium. Introducing diluent gases into hydrogen and oxygen respectively helps to improve the safety of the reaction and avoid violent reactions.

[0029] In a preferred embodiment, the volume fraction of the first diluent gas in the first feed gas is 50% or more, preferably 55% or more, and more preferably 60% or more. When the volume fraction of the first diluent gas in the first feed gas is within the optimized range provided in this embodiment, better in-situ reaction results can be achieved.

[0030] In one embodiment, the second feed gas further includes a second diluent gas; preferably, the volume fraction of the second diluent gas in the second feed gas is 50% by volume or more, more preferably 55% by volume or more, and even more preferably 60% by volume or more. When the volume fraction of the second diluent gas in the second feed gas is within the optimized range provided in this embodiment, better in-situ reaction results can be achieved.

[0031] In one specific embodiment, the mixture of reactant gas and dilution gas is passed into a liquid-phase reaction medium in which a catalyst is dispersed for contact reaction, which can be achieved in various reactors, such as in a high-pressure reactor.

[0032] In one embodiment, the ketone compound is selected from ketone compounds having 5 to 12 carbon atoms; preferably, it is selected from one or more of cyclopentanone, cyclohexanone, cycloheptanone, cyclooctanone, and acetophenone; more preferably, it is cyclohexanone. The method for preparing ketoxime compounds provided in this disclosure is applicable to the production of various ketone compounds to obtain the corresponding ketoximes.

[0033] In one embodiment, the Group IB metal is selected from one or more of gold, silver, and copper; the Group VIII metal is selected from one or more of ruthenium, palladium, platinum, rhodium, cobalt, nickel, and iridium; preferably, the active metal of the catalyst includes gold and palladium. This disclosure uses a combination of gold and palladium as the active metal of the catalyst to achieve higher conversion rates of ketone compounds and ketoxime selectivity.

[0034] In a preferred embodiment, based on the total weight of the catalyst, the content of the active metal is 0.01 to 20% by weight, including but not limited to 0.01%, 2%, 4%, 6%, 8%, 10%, 12%, 14%, 16%, 18%, and 20% by weight; preferably 0.01 to 5% by weight, including but not limited to 0.01%, 1%, 2%, 3%, 4%, and 5% by weight. When the loading of the active metal in the catalyst is within the optimized range provided in this embodiment, especially within the preferred content range, the catalyst can achieve superior catalytic performance, obtaining higher ketone conversion rates and ketoxime selectivity.

[0035] In a preferred embodiment, the molar ratio of gold to palladium in the catalyst is 1:0.01 to 20, including but not limited to 1:0.01, 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, 1:11, 1:12, 1:13, 1:14, 1:15, 1:16, 1:17, 1:18, 1:19, and 1:20; preferably 1:0.5 to 10. With the optimized molar ratio of gold to palladium provided in this embodiment, especially within the preferred molar ratio range, the catalyst exhibits superior catalytic performance, resulting in higher conversion rates of ketone compounds and ketoxime selectivity.

[0036] In a preferred embodiment, the support is a titanium-silicon molecular sieve (TS-1). This disclosure utilizes a combination of titanium-silicon molecular sieves with active metals, particularly with gold and palladium, to achieve better in-situ reaction results in the preparation of ketoxime compounds. Preferably, the molar ratio of silicon to titanium in the titanium-silicon molecular sieve is 10-300:1, including but not limited to 10:1, 50:1, 100:1, 150:1, 200:1, 250:1, and 300:1; more preferably 20-200:1, including but not limited to 20:1, 50:1, 80:1, 100:1, 120:1, 140:1, 160:1, 180:1, and 200:1. Using a titanium-silicon molecular sieve with the silicon-titanium molar ratio specified in this embodiment as a catalyst support enables the catalyst to achieve better in-situ reaction results.

[0037] In a more preferred embodiment, the supported catalyst used in this disclosure is a titanium-silicon molecular sieve catalyst supported on gold and palladium, wherein, based on the total weight of the catalyst, the loading of gold is 0.01~9.99 wt%, and the loading of palladium is 0.01~9.99 wt%. Preferably, the molar ratio of gold to palladium is 1:0.1~20; more preferably, the molar ratio of silicon to titanium in the titanium-silicon molecular sieve supported on gold and palladium is 20~200:1. Using the catalyst provided in this embodiment is more conducive to improving the conversion rate and selectivity of ketone compounds, resulting in the reaction for in-situ preparation of ketone oxime compounds having the highest possible ketone oxime formation efficiency.

[0038] In one specific embodiment, the gold and palladium-loaded titanium-silicon molecular sieve catalyst (AuPd / TS-1 catalyst) can be prepared by the following method, but is not limited to the following method: Under vigorous stirring and programmed temperature increase, TS-1 molecular sieves were added in small amounts multiple times to a homogeneous monomer phase composed of palladium acetate precursor salt solution and chloroauric acid precursor salt solution while continuously stirring. After the addition was completed, the temperature was raised to 50-120℃, and the mixture was aged for 2-24 hours. Excess aqueous solution was evaporated, and the resulting product was dried, calcined, reduced, and sieved to obtain an AuPd / TS-1 catalyst with a total metal loading of 0.01-20% by weight, preferably 0.1-5% by weight. The calcination conditions included heating to 400℃ for 3 hours in air at a heating rate of 10℃ / min; the reduction conditions included reducing to 350℃ for 4 hours in a 5% H2 / N2 atmosphere at a heating rate of 10℃ / min.

[0039] In one embodiment, the ammonia source is selected from one or more of ammonia water, ammonium chloride, ammonium bicarbonate, and ammonium carbonate; preferably, ammonium bicarbonate. Using the ammonia source provided in this embodiment, ammonia gas can be effectively released after being introduced into the reaction system for in-situ reaction to generate ketoxime.

[0040] In one embodiment, the liquid-phase reaction medium is a solvent with good solubility in the reaction raw material gas or low viscosity and low surface tension.

[0041] In one specific embodiment, the liquid medium is selected from one or more of water, methanol, ethanol, isopropanol, 1,4-dioxane and tert-butanol; preferably water and / or tert-butanol.

[0042] In a preferred embodiment, the weight ratio of the ketone compound to the catalyst is 1-100:1, preferably 15-50:1; the weight ratio of the liquid-phase reaction medium to the catalyst is 10-2000:1, preferably 1000-2000:1; and the weight ratio of the ammonia source to the catalyst in the liquid-phase reaction medium is 10-1000:1, preferably 10-500:1. Reaction according to the optimized feedstock weight ratios in this embodiment, especially those within the preferred range, can improve the formation efficiency of ketoxime compounds.

[0043] In one embodiment, the reaction conditions include: a reaction temperature of 0~200℃ and a reaction pressure of 1.0~10.0MPa.

[0044] In a preferred embodiment, the reaction temperature is 50~100℃, including but not limited to 50℃, 60℃, 70℃, 80℃, 90℃, and 100℃, and the reaction pressure is 3.0~6.0 MPa, including but not limited to 3MPa, 4MPa, 5MPa, and 6MPa. Following the reaction conditions provided in this embodiment, superior reaction results can be achieved.

[0045] In one embodiment, the method of this disclosure further includes rapidly adjusting the temperature of the reaction system to the temperature required for the formation of ketoxime using a constant temperature water bath.

[0046] In a preferred embodiment, the method further includes: heating the reaction system to the reaction temperature at a heating rate of 0.1~10℃ / min, including but not limited to 0.1℃ / min, 2℃ / min, 3℃ / min, 4℃ / min, 5℃ / min, 6℃ / min, 7℃ / min, 8℃ / min, 9℃ / min, 10℃ / min; preferably 0.5~5℃ / min.

[0047] In one embodiment, the method further includes component analysis of the reaction products; preferably, the reaction products are transported to a component analysis device under heating conditions of 20~200°C.

[0048] In one specific implementation, such as Figure 1 As shown, a flowchart of a method for preparing ketoxime compounds provided in this disclosure is illustrated. Figure 1In the reactor, a hydrogen / dilution gas mixture (first feed gas) and an oxygen / dilution gas mixture (second feed gas) are thoroughly mixed and contacted in a liquid-phase reaction medium, and then react in situ with ketone compounds and ammonia to obtain ketoxime products. The tail gas after the reaction is analyzed by gas chromatography to obtain the conversion rate of ketone compounds and the selectivity of ketoximes.

[0049] In one implementation, such as Figure 2 As shown, a laboratory reaction apparatus for the methods provided in this disclosure is illustrated. Figure 2 In this reactor, a high-pressure reaction vessel is installed, equipped with a polytetrafluoroethylene (PTFE) liner 9, a constant-temperature water bath, and a mechanical stirrer (electric stirrer 6). The reaction catalyst and liquid reaction medium are contained within the vessel. A mixture of hydrogen / dilution gas and oxygen / dilution gas is introduced through the inlet pipe at the reactor head, entering the liquid reaction medium and making full contact with the catalyst surface, where it reacts with ketone compounds and ammonia. After the reaction stops, the catalyst is separated from the reactants, and the liquid phase is collected and analyzed by gas chromatography. The reactor uses computer-controlled stirring rate and reaction time to maintain a constant reaction temperature throughout the entire reaction process.

[0050] The present disclosure is further described in detail below through examples. The raw materials used in the examples are commercially available.

[0051] In the examples and comparative examples, the ketoxime selectivity and ketone conversion were calculated using the methods shown in equations (1) to (2): Equation (1); Equation (2).

[0052] The reaction liquid phase was analyzed using an Agilent 7890 gas chromatograph with a flame ionization detector (FID) and a CP-Wax column. Quantitative analysis of the products was performed using the internal standard method.

[0053] The following preparation examples illustrate the preparation method of the catalyst.

[0054] Preparation Example 1 The AuPd / TS-1 catalyst used in the following examples was prepared by an impregnation method, including the following steps: Appropriate amounts of PdCl2 and HAuCl4·3H2O were dissolved in deionized water at a gold:palladium molar ratio of 1:0.1, and the solution was subjected to ultrasonic treatment to obtain a solution. Then, titanium silicate molecular sieve (TS-1) was added to the above solution, stirred thoroughly, and then placed in a dark place at room temperature for 12 h to allow the components to fully impregnate and diffuse. The solution was then dried in a 100℃ drying oven for 12 h, ground, and transferred to a tube furnace. Under air atmosphere, the temperature was increased to 400℃ at a heating rate of 10℃ / min, and then calcined for 3 h to obtain the AuPd / TS-1 catalyst.

[0055] The molar ratio of gold to palladium in the catalyst is 1:0.1; based on the total weight of the catalyst, the total content of gold and palladium is 1% by weight, with the remainder being the support; wherein the molar ratio of silicon to titanium in the titanium-silicon molecular sieve is 40:1.

[0056] Preparation Example 2 The AuPd / TiO2 catalyst used in the following examples was prepared by an impregnation method, similar to the preparation method of the AuPd / TS-1 catalyst in Preparation Example 1, except that TS-1 was replaced with the same mass of TiO2 support, resulting in an AuPd / TiO2 catalyst. Based on the total weight of the catalyst, the gold loading was 0.65 wt%, the palladium loading was 0.35 wt%, the total metal content was 1 wt%, and the balance was the support.

[0057] Preparation Example 3 This preparation example follows the catalyst preparation method described in Preparation Example 1, except that the type of metal source is adjusted to obtain a PtPd / TS-1 catalyst. The molar ratio of platinum to palladium in the catalyst is 1:0.1; based on the total weight of the catalyst, the platinum loading is 0.65 wt%, the palladium loading is 0.35 wt%, the total content of platinum and palladium is 1 wt%, and the remainder is the support. The molar ratio of silicon to titanium in the titanium-silicon molecular sieve is 40:1.

[0058] Preparation Example 4 This preparation example follows the catalyst preparation method in Preparation Example 1, except that the raw material ratio is adjusted to obtain an AuPd / TS-1 catalyst. The molar ratio of gold to palladium is 1:0.05; based on the total weight of the catalyst, the gold loading is 0.97 wt%, the palladium loading is 0.03 wt%, the total metal content is 1 wt%, and the balance is the support. The molar ratio of silicon to titanium in the titanium-silicon molecular sieve is 40:1.

[0059] Preparation Example 5 This preparation example follows the catalyst preparation method in Preparation Example 1, except that the raw material ratio is adjusted to obtain an AuPd / TS-1 catalyst. The molar ratio of gold to palladium in the catalyst is 1:0.01; based on the total weight of the catalyst, the gold loading is 0.99 wt%, the palladium loading is 0.01 wt%, the total metal content is 1 wt%, and the remainder is the support. The molar ratio of silicon to titanium in the titanium-silicon molecular sieve is 40:1.

[0060] The following examples illustrate the application of the catalysts obtained in the above preparation examples in the preparation of ketoximes from ketone compounds.

[0061] Example 1 This embodiment uses the AuPd / TS-1 catalyst obtained in Preparation Example 1. Figure 2 The reaction apparatus shown involves sequentially adding 1.7 mol tert-butanol, 1.6 mol water, 0.02 mol cyclohexanone, 0.04 mol ammonium bicarbonate, and 0.1 g AuPd / TS-1 catalyst to the reactor. The reactor is then sealed and the flanges are reinforced. Hydrogen is mixed with nitrogen dilution gas to obtain mixed gas I (hydrogen volume fraction 5% vol%, nitrogen dilution gas volume fraction 95% vol%). Oxygen is mixed with carbon dioxide dilution gas to obtain mixed gas II (oxygen volume fraction 25% vol%, carbon dioxide dilution gas volume fraction 75% vol%). The reactor and pipelines undergo three gas purgings, introducing hydrogen / carbon dioxide mixed gas I and oxygen / carbon dioxide mixed gas II respectively, maintaining a hydrogen to oxygen molar ratio of 0.6:1 throughout. The total pressure is 3.0 MPa, and the reaction system is heated to 80°C at a rate of 10°C / min. The reaction temperature is controlled by computer at 80°C, the stirring speed is 1200 r / min, and the reaction time is 3 h.

[0062] After the reaction, the catalyst was removed by filtration and a small amount of the filtrate was taken for analysis of the liquid phase product, yielding a cyclohexanone conversion rate of 92% and a cyclohexanone oxime selectivity of 96%.

[0063] Example 1-A This embodiment refers to the preparation method in Example 1, but differs from Example 1 in that... use Figure 2 The reaction apparatus shown was used to add 1.7 mol tert-butanol, 1.6 mol water, 0.02 mol cyclopentanone, 0.04 mol ammonium bicarbonate and 0.1 g AuPd / TS-1 catalyst sequentially to the reaction vessel, and the rest of the process was the same as in Example 1.

[0064] After the reaction, the catalyst was removed by filtration and a small amount of the filtrate was taken for analysis of the liquid phase product. The conversion rate of cyclopentanone was 55.3% and the selectivity of cyclopentanone oxime was 96.4%.

[0065] Example 1-B This embodiment refers to the preparation method in Example 1, but differs from Example 1 in that... use Figure 2 The reaction apparatus shown was used to sequentially add 1.7 mol tert-butanol, 1.6 mol water, 0.02 mol cycloheptanone, 0.04 mol ammonium bicarbonate and 0.1 g AuPd / TS-1 catalyst to the reaction vessel, and the rest of the process was the same as in Example 1.

[0066] After the reaction, the catalyst was removed by filtration and a small amount of the filtrate was taken for analysis of the liquid product. The conversion of cycloheptanone was 61.7% and the selectivity of cycloheptanone oxime was 96.8%.

[0067] Example 1-C This embodiment refers to the preparation method in Example 1, but differs from Example 1 in that... use Figure 2 The reaction apparatus shown was used to add 1.7 mol tert-butanol, 1.6 mol water, 0.02 mol cyclooctanone, 0.04 mol ammonium bicarbonate and 0.1 g AuPd / TS-1 catalyst sequentially to the reaction vessel. The rest of the process was the same as in Example 1.

[0068] After the reaction, the catalyst was removed by filtration and a small amount of the filtrate was taken for analysis of the liquid product. The conversion rate of cyclooctanone was 43.5% and the selectivity of cyclooctanone oxime was 95.5%.

[0069] Based on the data in Examples 1 and 1-A to 1-C above, it can be seen that the method for preparing ketoximes provided in this disclosure is applicable to a variety of ketone compound raw materials, and can obtain high ketone compound conversion rate and ketoxime selectivity; among them, Example 1 uses cyclohexanone as raw material, which can obtain higher ketone compound conversion rate and ketoxime selectivity.

[0070] Comparative Example 1 1.7 mol tert-butanol, 1.6 mol water, 0.02 mol cyclohexanone, 0.04 mol ammonium bicarbonate, and 0.2 g AuPd / TS-1 catalyst were added sequentially to the reactor. Hydrogen peroxide in the amount required for the complete reaction of hydrogen and oxygen to hydrogen peroxide in Example 1 was also added (i.e., without introducing mixed gases I and II into the reactor, but directly adding an amount of hydrogen peroxide equivalent to the amount of hydrogen peroxide produced by the complete reaction of hydrogen and oxygen in Example 1). The reactor was then quickly sealed and the flanges reinforced. Nitrogen gas with a total pressure of 3.0 MPa was introduced. The reaction temperature was controlled by computer at 80°C, the stirring speed at 1200 r / m, and the reaction time at 3 h.

[0071] After the reaction, the catalyst was removed by filtration and a small amount of the filtrate was taken for analysis of the liquid phase product, yielding a cyclohexanone conversion rate of 44% and a cyclohexanone oxime selectivity of 95%.

[0072] A comparison of Example 1 and Comparative Example 1 shows that in Comparative Example 1, the conversion rate of cyclohexanone was only 44% when hydrogen peroxide was directly added to the reaction. This indicates that the in-situ reaction preparation method provided in this disclosure has a higher conversion rate of ketone compounds and excellent selectivity for cyclohexanone oxime.

[0073] Comparative Example 2 This comparative example follows the preparation method described in Example 1, but differs from Example 1 in that... The reactor and pipelines underwent three gas purgings, with only an oxygen / nitrogen mixture II being introduced to control the total pressure of the reaction system to remain constant. The remaining processes were the same as in Example 1.

[0074] After the reaction, the catalyst was removed by filtration and a small amount of the filtrate was taken for analysis of the liquid phase product, yielding a cyclohexanone conversion of 8.6% and a cyclohexanone oxime selectivity of 0.8%.

[0075] Comparative Example 3 This comparative example follows the preparation method described in Example 1, but differs from Example 1 in that... The reactor and pipelines underwent three gas purgings, with only a hydrogen / nitrogen mixed gas I introduced to control the total pressure of the reaction system to remain constant. The rest of the process was the same as in Example 1.

[0076] After the reaction, the catalyst was removed by filtration and a small amount of the filtrate was taken for analysis of the liquid phase product, yielding a cyclohexanone conversion of 10.4% and a cyclohexanone oxime selectivity of 2.1%.

[0077] A comparison of Example 1 with Comparative Examples 2 and 3 shows that: in Comparative Example 2, only an oxygen / nitrogen mixture was introduced, and in Comparative Example 3, only a hydrogen / nitrogen mixture was introduced. The cyclohexanone conversion rate and cyclohexanone oxime selectivity obtained from the reactions in Comparative Examples 2 and 3 were both low. However, in Example 1, the method provided by this disclosure can simultaneously achieve high cyclohexanone conversion rate and cyclohexanone oxime selectivity, indicating that the method provided by this disclosure can simultaneously introduce hydrogen and oxygen to achieve excellent in-situ reaction of ketone compounds.

[0078] Comparative Example 4 This comparative example follows the preparation method in Example 1, except that the catalyst AuPd / TS-1 is replaced with the catalyst AuPd / TiO2 prepared in Preparation Example 2; the rest of the process is the same as in Example 1.

[0079] After the reaction, the catalyst was removed by filtration and a small amount of the filtrate was taken for analysis of the liquid phase product, yielding a cyclohexanone conversion rate of 3.9% and a cyclohexanone oxime selectivity of 99%.

[0080] Comparing this comparative example with Example 1, it can be seen that the catalyst in this comparative example, with Au and Pd as active metal components and TiO2 as support, has a low cyclohexanone conversion rate of only 3.9% in the in-situ reaction; while the catalyst with the composition AuPd / TS-1 prepared in Example 1 has a higher cyclohexanone conversion rate and cyclohexanone oxime selectivity in the reaction of cyclohexanone to cyclohexanone oxime.

[0081] Example 2 use Figure 2 The reaction apparatus shown involves sequentially adding 1.7 mol tert-butanol, 1.6 mol water, 0.02 mol cyclohexanone, 0.04 mol ammonium bicarbonate, and 0.2 g AuPd / TS-1 catalyst to the reactor. The reactor is then sealed and the flanges are reinforced. Hydrogen is mixed with nitrogen dilution gas to obtain mixed gas I (hydrogen volume fraction of 5 vol%). Oxygen is mixed with carbon dioxide dilution gas to obtain mixed gas II (oxygen volume fraction of 25 vol%). The reactor and pipelines undergo three gas purgings, introducing hydrogen / carbon dioxide mixed gas I and oxygen / carbon dioxide mixed gas II respectively, while maintaining a hydrogen to oxygen molar ratio of 0.6:1 throughout. The total pressure is 3 MPa, and the reaction temperature is controlled by computer at 160℃, the stirring speed at 1000 r / min, and the reaction time at 3 h.

[0082] After the reaction, the catalyst was removed by filtration and a small amount of the filtrate was taken for analysis of the liquid phase product, yielding a cyclohexanone conversion rate of 37% and a cyclohexanone oxime selectivity of 79%.

[0083] Comparing this embodiment with Example 1, it can be seen that the cyclohexanone oxime prepared in Example 1 according to the preferred conditions of the in-situ reaction provided in this disclosure has a higher cyclohexanone conversion rate and cyclohexanone oxime selectivity compared to Example 7.

[0084] Example 3 This embodiment refers to the preparation method in Example 1, except that the catalyst AuPd / TS-1 is replaced with the catalyst PtPd / TS-1 prepared in Preparation Example 3; the rest of the process is the same as in Example 1.

[0085] After the reaction, the catalyst was removed by filtration and a small amount of the filtrate was taken for analysis of the liquid product. The cyclohexanone conversion rate was 41.3% and the cyclohexanone oxime selectivity was 95.5%.

[0086] Comparing this embodiment with Example 1, it can be seen that the catalyst in this embodiment, which uses Pt and Pd as metal components and TS-1 support, has a low cyclohexanone conversion rate in the in-situ reaction; while the catalyst with the composition AuPd / TS-1 prepared in Example 1 has a higher cyclohexanone conversion rate and cyclohexanone oxime selectivity in the reaction of cyclohexanone to cyclohexanone oxime.

[0087] Example 4 This embodiment refers to the preparation method in Example 1, except that the catalyst AuPd / TS-1 is replaced with the catalyst AuPd / TS-1 prepared in Preparation Example 4; the rest of the process is the same as in Example 1.

[0088] After the reaction, the catalyst was removed by filtration and a small amount of the filtrate was taken for analysis of the liquid phase product. The cyclohexanone conversion rate was 19.8% and the cyclohexanone oxime selectivity was 98.1%.

[0089] Example 5 This embodiment refers to the preparation method in Example 1, except that the catalyst AuPd / TS-1 is replaced with the catalyst AuPd / TS-1 prepared in Preparation Example 5; the rest of the process is the same as in Example 1.

[0090] After the reaction, the catalyst was removed by filtration and a small amount of the filtrate was taken for analysis of the liquid phase product. The cyclohexanone conversion rate was 12.4% and the cyclohexanone oxime selectivity was 98.6%.

[0091] Comparing Examples 4-5 with Example 1, it can be seen that the molar ratio of gold to palladium in the AuPd / TS-1 catalyst used in Examples 4-5 is not within the preferred molar ratio range provided in this disclosure; while the AuPd / TS-1 catalyst used in Example 1 has a preferred molar ratio of gold to palladium, and Example 1 has a higher cyclohexanone conversion rate and cyclohexanone oxime selectivity in the reaction of cyclohexanone to cyclohexanone oxime.

[0092] Example 6 This embodiment follows the preparation method described in Example 1, except that hydrogen is mixed with nitrogen dilution gas to obtain mixed gas I (hydrogen volume fraction of 5%); oxygen is mixed with carbon dioxide dilution gas to obtain mixed gas II (oxygen volume fraction of 25%). The reactor and pipelines undergo three gas purgings, introducing hydrogen / carbon dioxide mixed gas I and oxygen / carbon dioxide mixed gas II respectively, while maintaining the molar ratio of hydrogen to oxygen at 6.5:1 throughout. The total pressure is 5 MPa. The remaining processes are the same as in Example 1.

[0093] After the reaction, the catalyst was removed by filtration and a small amount of the filtrate was taken for analysis of the liquid phase product, and the cyclohexanone conversion rate was 23% and the cyclohexanone oxime selectivity was 99%.

[0094] This embodiment is compared with Example 1, in which the in-situ reaction was carried out according to the preferred molar ratio of hydrogen to oxygen. Example 1 has a higher cyclohexanone conversion rate in the reaction of cyclohexanone to cyclohexanone oxime.

[0095] Example 7 This embodiment refers to the preparation method in Example 1, except that the total pressure is 1 MPa, the reaction temperature is controlled by computer at 200°C, the stirring speed is 1200 r / min, the reaction time is 8 h, and the rest of the process is the same as in Example 1.

[0096] After the reaction, the catalyst was removed by filtration and a small amount of the filtrate was taken for analysis of the liquid phase product, yielding a cyclohexanone conversion of 40% and a cyclohexanone oxime selectivity of 75%.

[0097] Comparing this example with Example 1, it can be seen that the cyclohexanone oxime was prepared using the preferred reaction conditions in Example 1, and the reaction in Example 1 has a higher cyclohexanone conversion rate and cyclohexanone oxime selectivity.

[0098] Example 8 This embodiment refers to the preparation method in Example 1, except that the total pressure is 0.5 MPa, the reaction temperature is controlled by computer at 350°C, the stirring speed is 1200 r / min, the reaction time is 12 h, and the rest of the process is the same as in Example 1.

[0099] After the reaction, the catalyst was removed by filtration and a small amount of the filtrate was taken for analysis of the liquid phase product, yielding a cyclohexanone conversion rate of 33% and a cyclohexanone oxime selectivity of 41%.

[0100] Comparing Example 8 with Example 7, it can be seen that the cyclohexanone conversion rate and cyclohexanone oxime selectivity are higher in Example 7, which is prepared according to the optimized process conditions provided in this disclosure.

[0101] The preferred embodiments of this disclosure have been described in detail above. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0102] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0103] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A method for preparing ketoxime compounds, characterized in that, Includes the following steps: A ketone compound, a catalyst, and an ammonia source are contacted in a liquid medium to obtain a reaction mixture, wherein the ammonia source releases ammonia gas; the catalyst includes a support and an active metal supported on the support; the active metal includes Group IB metals and Group VIII metals; and the support includes a titanium silicate molecular sieve. A first feed gas and a second feed gas are introduced into the reaction mixture and contacted with a catalyst to carry out an in-situ reaction, yielding a reaction product containing ketoxime compounds; wherein the first feed gas includes hydrogen and the second feed gas includes oxygen.

2. The method according to claim 1, characterized in that, The volume fraction of hydrogen in the first raw material gas is less than 15% by volume, preferably less than 10% by volume. The oxygen volume fraction in the second raw material gas is greater than 5% by volume, preferably greater than 7% by volume. More preferably, the molar ratio of hydrogen to oxygen is 0.01 to 10:1, more preferably 0.16 to 5:

1.

3. The method according to claim 1, characterized in that, The first raw material gas further includes a first dilution gas; preferably, the volume fraction of the first dilution gas in the first raw material gas is 50% or more, more preferably 55% or more, and even more preferably 60% or more. The second raw material gas also includes a second dilution gas; preferably, the volume fraction of the second dilution gas in the second raw material gas is 50% or more, more preferably 55% or more, and even more preferably 60% or more. Optionally, the first diluting gas and the second diluting gas are each independently selected from one or more of nitrogen, carbon dioxide, argon and helium.

4. The method according to claim 1, characterized in that, The ketone compound is selected from ketone compounds having 5 to 12 carbon atoms; preferably, it is selected from one or more of cyclopentanone, cyclohexanone, cycloheptanone, cyclooctanone, and acetophenone; more preferably, it is cyclohexanone.

5. The method according to claim 1, characterized in that, The Group IB metals are selected from one or more of gold, silver, and copper; the Group VIII metals are selected from one or more of ruthenium, palladium, platinum, rhodium, cobalt, nickel, and iridium; preferably, the active metals of the catalyst include gold and palladium; more preferably, the molar ratio of gold to palladium in the catalyst is 1:0.01~20, more preferably 1:0.5~10; preferably, based on the total weight of the catalyst, the content of the active metal is 0.01~20% by weight, more preferably 0.01~5% by weight. The carrier is a titanium-silicon molecular sieve; preferably, the molar ratio of silicon to titanium in the titanium-silicon molecular sieve is 10~300:1, more preferably 20~200:

1.

6. The method according to claim 1, characterized in that, The ammonia source is selected from one or more of ammonia water, ammonium chloride, ammonium bicarbonate and ammonium carbonate; preferably, ammonium bicarbonate.

7. The method according to claim 1, characterized in that, The liquid medium is selected from one or more of water, methanol, ethanol, isopropanol, 1,4-dioxane and tert-butanol; preferably tert-butanol and optionally water, and more preferably, the volume ratio of water to tert-butanol is 0~20:

1.

8. The method according to claim 1, characterized in that, The reaction conditions for the in-situ reaction include: a reaction temperature of 0~300℃, a reaction pressure of 1.0~20.0 MPa, and a reaction time of 0.5~10h; preferably, the reaction temperature is 20~250℃, the reaction pressure is 3.0~10.0 MPa, and the reaction time is 1~5h.

9. The method according to claim 8, characterized in that, The method further includes heating the reaction system to the reaction temperature at a heating rate of 0.1~10℃ / min, preferably 0.5~5℃ / min.

10. The method according to claim 1, characterized in that, The weight ratio of the ketone compound to the catalyst is 1~100:1, preferably 15~50:1; The weight ratio of the liquid phase reaction medium to the catalyst is 10~2000:1, preferably 1000~2000:1; The weight ratio of the ammonia source to the catalyst in the liquid reaction medium is 10~1000:1, preferably 10~500:1.

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