Process and system for the ammoximation of a carbonyl compound

Abstract

This invention relates to the field of ammonium oxime reaction technology, and discloses a method and system for the ammonium oxime reaction of carbonyl compounds. The method includes: (1) contacting a reaction system containing a carbonyl compound, ammonia, and hydrogen peroxide with a catalyst to carry out an ammonium oxime reaction, obtaining a product mixture; (2) mixing the product mixture with an organic solvent, and then simultaneously extracting and filtering under stirring conditions to obtain wastewater and a mixed liquid; (3) separating the mixed liquid to obtain an oxime-containing organic phase and an aqueous phase containing a catalyst, and returning the aqueous phase containing the catalyst to step (1) to provide at least a portion of the catalyst. Using the carbonyl compound ammonium oxime reaction method provided by this invention, continuous and efficient separation of wastewater, catalyst, and reaction products can be achieved while ensuring high carbonyl compound conversion rate and high oxime selectivity, and the device operates with good stability.

Description

Technical Field

[0001] This invention relates to the field of ammoniation reaction technology, and more specifically to a method and system for the ammoniation of carbonyl compounds. Background Technology

[0002] Carbonyl compounds refer to compounds containing the >C=O functional group, such as aldehydes and ketones. The reaction of carbonyl compounds with hydroxylamine is the main method for synthesizing the corresponding oxime compounds. Taking the synthesis of cyclohexanone oxime as an example, cyclohexanone oxime is a key intermediate in the production of caprolactam, an important organic chemical raw material mainly used as a monomer for nylon-6 synthetic fibers and engineering plastics. Industrially, 98% of caprolactam is produced via the cyclohexanone oxime route. The traditional production processes for cyclohexanone oxime mainly include the hydroxylamine sulfate method (HSO), the nitrogen oxide reduction method (NO), and the hydroxylamine phosphate method (HPO). All three methods produce cyclohexanone oxime through the reaction of cyclohexanone with a salt of hydroxylamine. The preparation of different hydroxylamine salts involves first burning ammonia to produce nitrogen oxides or their salts, followed by reduction (such as hydrogenation). This process is not only lengthy, complex, and demanding, requiring stringent conditions and high equipment investment, but also generates or uses NO. X and / or SO X This leads to serious corrosion and pollution problems.

[0003] The one-step ammoximation reaction of carbonyl compounds with ammonia and hydrogen peroxide to prepare oximes is a green chemical reaction. Currently, newly built industrial production facilities all adopt the ammoximation process of cyclohexanone to prepare cyclohexanone oximes. This process uses titanium silicate molecular sieve catalysts, tert-butanol as solvent, and cyclohexanone, ammonia, and hydrogen peroxide as raw materials to prepare cyclohexanone oximes with high selectivity in one step. It not only has mild reaction conditions and high yield of target products, but also has advantages such as simple process, low equipment investment, low emissions of waste, and environmental friendliness.

[0004] tert-Butanol, used as a solvent in the ammonoximation reaction, needs to be recycled, and steam consumption occurs during distillation to recover it. In recent years, research on ammonoximation processes that do not use tert-butanol as a solvent has been increasing in order to reduce energy consumption.

[0005] CN105837468A discloses a method for preparing cyclohexanone oxime. The method uses an aqueous solution containing a small amount of inert organic solvent as the solvent, and cyclohexanone, ammonia, and hydrogen peroxide undergo an ammonoximation reaction in the solvent in the presence of an oximation catalyst. The ammonoximation reaction product is separated into an organic phase and an aqueous phase in a hydrocyclone separator and / or decanter. The oximation catalyst is then separated from the aqueous phase in a decanter, membrane filter, or other equipment. This method involves high operating loads on the separation equipment and is difficult to control.

[0006] CN114436889A discloses an integrated method and apparatus for ammonium oximation reaction and separation, comprising the following steps: (1) under the condition of titanium silicate molecular sieve as catalyst, ketone, hydrogen peroxide and ammonia react to generate oxime; (2) the reactants are separated into a clear liquid containing water and oxime by cross-flow filtration; (3) the material after separation of the clear liquid is partially entered into mixed extraction before being recycled back to the reactor, and an inert alkane solvent is added for extraction, and the resulting organic phase is an oxime solution; (4) the aqueous phase turbid liquid containing catalyst after extraction is returned to the ammonium oximation reaction system. This method adopts a process of filtration followed by extraction and phase separation. The filtration system is unstable, the filter is prone to clogging, affecting normal production; moreover, oxime will be filtered out along with the aqueous phase, and the oxime content in the clear liquid is high, which increases the difficulty of subsequent processing and easily causes oxime loss. Summary of the Invention

[0007] The purpose of this invention is to overcome the problems of high energy consumption and easy loss of oxime in the separation of products from ammonoximation reaction in the prior art, and to provide an ammonoximation method and ammonoximation reaction system for carbonyl compounds. This method has the characteristics of high conversion rate of carbonyl compounds and oxime selectivity, good product separation effect and good operation stability.

[0008] To achieve the above objectives, the present invention provides a method for the ammonoximation of a carbonyl compound, the method comprising:

[0009] (1) The reaction system containing carbonyl compounds, ammonia and hydrogen peroxide is contacted with a catalyst to carry out an ammonium oxime reaction to obtain a mixture of products;

[0010] (2) The product mixture is mixed with an organic solvent, and then extracted and filtered simultaneously under stirring conditions to obtain wastewater and mixed liquid;

[0011] (3) Separate the mixture to obtain an oxime-containing organic phase and a catalyst-containing aqueous phase, and return the catalyst-containing aqueous phase to step (1) to provide at least a portion of the catalyst.

[0012] A second aspect of the present invention provides an ammonoximation reaction system for carbonyl compounds, the reaction system comprising a carbonyl compound supply unit, an ammonia supply unit, a hydrogen peroxide supply unit, an organic solvent supply unit, an ammonoximation reaction unit, an extraction separator, and a catalyst separator;

[0013] The ammonium oxime reaction unit includes at least one reactor for ammonium oxime reaction of carbonyl compound, ammonia and hydrogen peroxide from carbonyl compound supply unit, ammonia supply unit and hydrogen peroxide supply unit.

[0014] The outlet of the ammonium oxime reaction unit is connected to the inlet of the extraction separator through a mixing pipeline. The extraction separator is equipped with a filter, a wastewater outlet, and a mixed liquid outlet.

[0015] The mixing pipeline is provided with an organic solvent inlet connected to the organic solvent supply unit, which is used to mix the organic solvent with the ammonium oxime reaction product and then send it into the extraction separator.

[0016] The feed inlet of the catalyst separator is connected to the mixed liquid outlet of the extraction separator, and is used to feed the mixed liquid from the extraction separator into the catalyst separator; the aqueous phase outlet of the catalyst separator is connected to the ammonium oxime reaction unit, and is used to return the aqueous phase containing the catalyst to the reactor.

[0017] The ammonoximation method for carbonyl compounds provided by this invention involves mixing the product mixture of the ammonoximation reaction of carbonyl compounds with an organic solvent, and simultaneously extracting and filtering under stirring conditions, thereby achieving the dual purpose of extracting reaction products and separating wastewater. The mixture is then separated, allowing the oxime-containing organic phase and the catalyst-containing aqueous phase to naturally separate, achieving separation of reaction products and catalyst, and enabling catalyst recycling. Using the ammonoximation method for carbonyl compounds provided by this invention, continuous and efficient separation of wastewater, catalyst, and reaction products can be achieved while ensuring high carbonyl compound conversion and high oxime selectivity. The process is simple, significantly reducing separation load and equipment requirements, substantially lowering energy consumption and investment, and improving the stability of equipment operation. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the amoximation reaction system of carbonyl compounds in some embodiments of the present invention;

[0019] Figure 2 This is a schematic diagram of the reaction system used in the comparative example of this invention.

[0020] Explanation of reference numerals in the attached figures

[0021] 1. Carbonyl compound supply unit; 2. Ammonia supply unit; 3. Hydrogen peroxide supply unit.

[0022] 4 Organic solvent supply unit; 5 Ammoniation reaction unit; 6 Extraction separator.

[0023] 7 Filter 8 Catalyst Separator 9 Filter Tank

[0024] 10 Extractors Detailed Implementation

[0025] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and 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.

[0026] The first aspect of this invention provides a method for the ammonoximeation of a carbonyl compound, the method comprising:

[0027] (1) The reaction system containing carbonyl compounds, ammonia and hydrogen peroxide is contacted with a catalyst to carry out an ammonium oxime reaction to obtain a mixture of products;

[0028] (2) The product mixture is mixed with an organic solvent, and then extracted and filtered simultaneously under stirring conditions to obtain wastewater and mixed liquid;

[0029] (3) Separate the mixture to obtain an oxime-containing organic phase and a catalyst-containing aqueous phase, and return the catalyst-containing aqueous phase to step (1) to provide at least a portion of the catalyst.

[0030] According to the ammoximation method for carbonyl compounds of the present invention, the product mixture of the ammoximation reaction of carbonyl compounds is mixed with an organic solvent. Under stirring conditions, extraction and filtration are performed simultaneously, thereby achieving the dual effects of extracting reaction products and separating wastewater. The oxime-containing organic phase and the catalyst-containing aqueous phase in the mixture are then naturally separated, achieving separation of reaction products and catalyst, and catalyst recycling. Using the ammoximation method for carbonyl compounds provided by the present invention, continuous and efficient separation of wastewater, catalyst, and reaction products can be achieved while ensuring high carbonyl compound conversion and high oxime selectivity. The process is simple, significantly reducing separation load and equipment, substantially lowering energy consumption and investment, and improving the stability of plant operation.

[0031] According to the present invention, the ammonium oxime method can be applied to the preparation of corresponding oxime compounds from any conventional carbonyl compound in the art.

[0032] Preferably, no additional organic solvent is introduced in the ammonium oxime reaction in step (1). The organic solvent can be any organic solvent commonly used in the art, such as tert-butanol.

[0033] According to some preferred embodiments of the present invention, the carbonyl compound is selected from C3-C4. 10 aliphatic ketones, C5-C 10 Cyclic aliphatic ketones or aromatic ketones, C5-C 10The carbonyl compound is selected from at least one of cyclic aliphatic aldehydes or aromatic aldehydes. Preferably, the carbonyl compound is selected from at least one of cyclohexanone, acetone, methyl ethyl ketone, cyclopentanone, acetophenone, p-hydroxyacetophenone, furfural, benzaldehyde, and p-methylbenzaldehyde.

[0034] The present invention does not impose any particular limitation on the selection of the catalyst, and any conventional ammonia oxime reaction catalyst in the art can be used. Preferably, the catalyst comprises a titanium silicate molecular sieve, wherein the titanium silicate molecular sieve is selected from at least one of TS-1, TS-2, Ti-ZSM-5, Ti-ZSM-12, Ti-ZSM-48, Ti-β, Ti-MCM-41, Ti-MOR, Ti-MWW, and Ti-SBA-15.

[0035] The present invention does not particularly limit the form of the catalyst, which can be in the form of molecular sieve powder or a shaped catalyst formed by arbitrary shaping. Those skilled in the art can choose according to actual needs.

[0036] According to some preferred embodiments of the present invention, the reaction system in step (1) further includes a liquid silicon-containing additive. Using the above preferred embodiments helps to further suppress the dissolution of silicon in the catalyst, reduce catalyst deactivation, and further improve the stability of the reaction.

[0037] The liquid silicon-containing additive can be in liquid form such as sol, solution, suspension, or emulsion. The silicon-containing additive can be an inorganic silicon-containing substance and / or an organic silicon-containing substance.

[0038] Preferably, the inorganic silicon-containing material is silicon oxide and / or silicate, and the silicate can be sodium silicate, potassium silicate, aluminum silicate, etc. The organic silicon-containing material is preferably silicate ester and / or silane, and the silicate ester is preferably ethyl silicate.

[0039] According to some preferred embodiments of the present invention, the amount of liquid silicon-containing additive used is such that the silicon concentration in the reaction system is 0.1-10000 ppm. Preferably, the amount added is sufficient to bring the silicon content in the reaction solution to its dissolution equilibrium concentration. Those skilled in the art will understand that the equilibrium concentration of silicon in the system will vary depending on the composition of the reaction system, and they can add an appropriate amount of silicon-containing additive according to actual needs. Preferably, the amount of liquid silicon-containing additive used is such that the silicon concentration in the reaction system is 30-3000 ppm.

[0040] According to some preferred embodiments of the present invention, in step (1), the molar ratio of the carbonyl compound, hydrogen peroxide and ammonia is 1:(1-2):(1-3), preferably 1:(1-1.5):(1-2).

[0041] According to the present invention, preferably, the hydrogen peroxide is provided by hydrogen peroxide solution, wherein the mass fraction of hydrogen peroxide in the hydrogen peroxide solution is 10-80%, preferably 20-70%.

[0042] Preferably, in step (3), the mass fraction of the catalyst in the aqueous phase containing the catalyst returned from step (1) is 0.5-15%, more preferably 2-10%.

[0043] According to the present invention, preferably, the temperature of the ammonium oxime reaction is 50-100°C, more preferably 60-95°C, and the reaction pressure is 0-1 MPa, more preferably 0.1-0.6 MPa. In this invention, unless otherwise specified, all pressures refer to gauge pressure.

[0044] According to the present invention, in step (2), the product mixture is mixed with an organic solvent, and the oxime is extracted into the organic phase to form a mixture of organic phase, aqueous phase and catalyst.

[0045] The present invention has a wide range of choices for the organic solvents used in step (2), and conventional organic solvents that are insoluble or slightly soluble in water can be used in the present invention. Preferably, the organic solvent is selected from C6-C. 12 Alkanes, C5-C 11 Cycloalkanes, C6-C 10 It can be at least one of aromatic hydrocarbons and C6-C8 alcohols, such as n-hexane, cyclohexane, benzene, toluene, isohepyl alcohol, isooctyl alcohol, etc.

[0046] According to some preferred embodiments of the present invention, the mass ratio of the organic solvent to the product mixture (based on carbonyl compounds) is (1-10):1, for example, it can be a specific but not limiting mass ratio or any range between the two, such as 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, etc. Preferably, the mass ratio of the organic solvent to the product mixture (based on carbonyl compounds) is (1-6):1.

[0047] In this invention, in step (2), "simultaneous extraction and filtration" means that extraction and filtration are carried out in the same process, such as extraction and filtration in the same reactor, so as to achieve synchronous operation of extraction and filtration.

[0048] According to the present invention, in step (2), after the product mixture is mixed with an organic solvent, it is filtered during the extraction process. The mixture is stirred and mixed, which not only achieves efficient extraction but also selectively separates water. That is, only the aqueous phase passes through the filter, while the organic phase and catalyst are retained, thereby achieving efficient separation of the aqueous phase. Moreover, this method has a low filtration load. Preferably, the amount of wastewater filtered out is controlled to be the amount of water introduced into the system, including the amount of water generated in the reaction, the amount of water brought in by hydrogen peroxide, and may also include the amount of aqueous solution in the liquid silicon-containing additive, in order to maintain the water balance of the system.

[0049] According to some preferred embodiments of the present invention, the amount of wastewater filtered out is controlled to be 2-25 wt%, preferably 3-20 wt%, based on the mass of the aqueous phase in the product mixture.

[0050] Understandably, in the above process, most of the oxime products dissolve in the organic solvent, and the aqueous phase, as the raffinate phase, has a significantly reduced oxime content. This helps to reduce the difficulty of subsequent wastewater treatment, greatly reduce oxime loss, and ensures good operational stability of the device. The filtered aqueous phase can be recycled as wastewater, for example, by further recovering ammonia and a small amount of oxime, followed by biochemical treatment. Those skilled in the art can choose according to actual needs; this invention does not have special requirements in this regard, as long as wastewater discharge standards are met.

[0051] Preferably, in step (2), the mass fraction of oxime in the wastewater is 0.01-3%, more preferably 0.01-2%.

[0052] According to some preferred embodiments of the present invention, in step (2), the extraction temperature is 20-90°C, preferably 40-80°C.

[0053] According to the present invention, preferably, the filtration accuracy in step (2) is 0.01-50 μm, more preferably 2-30 μm.

[0054] In this invention, the extraction and filtration in step (2) can be performed using any device in the art, as long as it can achieve the dual functions of extraction and filtration.

[0055] According to some preferred embodiments of the present invention, the extraction and filtration in step (2) are carried out in an extraction separator, and the extraction separator is provided with a filter.

[0056] The present invention does not have any particular limitation on the material of the filter. Preferably, the material of the filter is ceramic or metal, and more preferably metal.

[0057] According to the present invention, in step (3), the mixture is separated to obtain an oxime-containing organic phase and an aqueous phase containing the catalyst. In the present invention, the oxime-containing organic phase does not contain the catalyst, and the catalyst is dispersed in the aqueous phase. Since the density difference between the organic phase and the aqueous phase is large, the catalyst and the reaction product can be separated by the natural phase separation of the organic phase and the aqueous phase. The organic phase contains oxime and solvent, and can be sent to the next process as needed. The aqueous phase is a catalyst slurry and returns to step (1) to provide at least a portion of the catalyst.

[0058] According to some preferred embodiments of the present invention, the separation in step (3) is carried out in a catalyst separator, wherein the aqueous phase section of the catalyst separator is provided with a stirrer for stirring the aqueous phase.

[0059] By installing a stirrer in the aqueous phase section of the catalyst separator, both catalyst deposition in the separator and mixing of the organic and aqueous phases can be prevented, ensuring continuous and stable separation of the two phases and catalyst circulation. Therefore, efficient separation of catalyst and reaction products can be achieved without the need for separation equipment such as hydrocyclones, decanters, and membrane filters, reducing material loss.

[0060] The present invention does not have special requirements for the rotation speed of the stirrer. Those skilled in the art can select it according to different equipment size, stirrer type, stirring blade diameter, etc., as long as it can prevent the catalyst from depositing in the catalyst separator and prevent the organic phase from mixing with the water phase.

[0061] Preferably, the catalyst separator is provided with a gas phase outlet at the top for discharging non-condensable gases (such as ammonia, gaseous products generated by the reaction) from the catalyst separator.

[0062] A second aspect of the present invention provides an ammonoximation reaction system for carbonyl compounds, such as... Figure 1 As shown, the reaction system includes a carbonyl compound supply unit 1, an ammonia supply unit 2, a hydrogen peroxide supply unit 3, an organic solvent supply unit 4, an ammonium oxime reaction unit 5, an extraction separator 6, and a catalyst separator 8.

[0063] The ammonium oxime reaction unit includes at least one reactor for ammonium oxime reaction of carbonyl compound, ammonia and hydrogen peroxide from carbonyl compound supply unit, ammonia supply unit and hydrogen peroxide supply unit.

[0064] The outlet of the ammonium oxime reaction unit is connected to the inlet of the extraction separator through a mixing pipeline. The extraction separator is equipped with a filter, a wastewater outlet, and a mixed liquid outlet.

[0065] The mixing pipeline is provided with an organic solvent inlet connected to the organic solvent supply unit, which is used to mix the organic solvent with the ammonium oxime reaction product and then send it into the extraction separator.

[0066] The feed inlet of the catalyst separator 8 is connected to the mixed liquid outlet of the extraction separator, and is used to feed the mixed liquid from the extraction separator 6 into the catalyst separator; the aqueous phase outlet of the catalyst separator is connected to the ammonium oxime reaction unit, and is used to return the aqueous phase containing the catalyst to the reactor.

[0067] The present invention does not impose a particular limitation on the number of reactors in the ammonium oximation reaction unit. Those skilled in the art can select and set one or more reactors according to actual production needs, and two or more reactors can be connected in series. Preferably, the ammonium oximation reaction unit includes 1-4 reactors, more preferably 1-2 reactors.

[0068] The present invention does not have any particular limitation on the type of reactor, but preferably, the reactor is a stirred tank reactor.

[0069] According to the present invention, when multiple reactors are connected in series, preferably each reactor is independently connected to the hydrogen peroxide supply unit so that hydrogen peroxide is fed simultaneously through multiple reactors.

[0070] According to the present invention, preferably, the reaction system further includes an auxiliary agent supply unit for supplying a silicon-containing auxiliary agent to the ammonium oxime reaction unit.

[0071] According to the present invention, the outlet of the ammonium oximation reaction unit is connected to the inlet of the extraction separator through a mixing pipeline. An organic solvent inlet is provided on the pipeline for mixing the product mixture from the ammonium oximation reaction unit with an organic solvent and then sending it into the extraction separator.

[0072] According to some preferred embodiments of the present invention, in the extraction separator, the filter is made of ceramic or metal, preferably metal.

[0073] Preferably, the filtration accuracy of the filter is 0.01-50μm, and more preferably 2-30μm.

[0074] In this invention, it is understood that the mixed liquid is separated into an aqueous phase and an organic phase in the catalyst separator. The aqueous phase section of the catalyst separator is equipped with a stirrer to agitate the aqueous phase containing the catalyst, which prevents both catalyst deposition in the catalyst separator and mixing of the organic and aqueous phases. Therefore, efficient separation of the catalyst and reaction products can be achieved without the need for separation equipment such as hydrocyclones, decanters, and membrane filters, reducing material loss.

[0075] Preferably, the catalyst separator is provided with a gas phase outlet at the top for discharging non-condensable gases (such as ammonia, gaseous products generated by the reaction) from the catalyst separator.

[0076] In this invention, the oxime-containing organic phase obtained by separation in step (3) can be directly sent to the next process, or it can be sent to the next process after optional solvent separation. Those skilled in the art can choose according to actual needs.

[0077] According to the present invention, the above-mentioned devices are connected by a logistics pipeline, and a delivery pump may or may not be installed on the logistics pipeline. Preferably, no delivery pump is installed on the connecting pipeline between the ammonia oxime reaction unit and the extraction separator, and between the extraction separator and the catalyst separator, and the material is discharged and fed by overflow.

[0078] According to some preferred embodiments of the present invention, the above-described reaction system is used for the ammonium oximation reaction of carbonyl compounds, specifically comprising: feeding a carbonyl compound, ammonia, hydrogen peroxide, and a catalyst into an ammonium oximation reaction unit to carry out the ammonium oximation reaction, obtaining a product mixture; mixing the product mixture from the outlet of the ammonium oximation reaction unit with an organic solvent in a mixing pipeline, and then feeding it into an extraction separator, wherein the extraction separator is equipped with a filter and a stirrer; under stirring conditions, a portion of the aqueous phase is controlled to be separated by the filter and discharged from the system through a wastewater outlet; and the mixed liquid is fed into a catalyst separator through the mixed liquid outlet. The mixed liquid is separated into an aqueous phase and an organic phase in the catalyst separator; the aqueous phase section of the catalyst separator is equipped with a stirrer for stirring the aqueous phase containing the catalyst; the aqueous phase containing the catalyst is returned to the ammonium oximation reaction unit, and the organic phase containing oxime is fed into the next process.

[0079] The present invention will be described in detail below through embodiments.

[0080] Example 1

[0081] Adopting such Figure 1 The reaction system shown.

[0082] Cyclohexanone, ammonia, and hydrogen peroxide are fed into a reactor and reacted at 89-91℃ and 0.4MPa. The effective volume of the reactor is 300mL, and it contains a TS-1 titanium-silicon molecular sieve catalyst. The feed rates are: cyclohexanone 35g / h, ammonia 8g / h, and hydrogen peroxide (35% hydrogen peroxide by mass) 40g / h. The reactants overflow from the reactor outlet and are mixed with toluene before being fed into an extraction separator at a toluene flow rate of 85g / h. The extraction separator contains a sintered metal filter with a filtration accuracy of 10-20μm. The mixture is stirred and extracted at 50℃. Simultaneously, a portion of the aqueous phase is separated by the filter. The flow rate of the filtered clear liquid is controlled by a pump at 40.5g / h (6.3% of the aqueous phase of the reaction mixture). The oxime content in the filtered clear liquid is 0.98%. This filtered clear liquid is sent as wastewater to the next process. The remaining mixture overflows into a catalyst separator. The material is separated into an organic phase and an aqueous phase in the catalyst separator. The catalyst separator is equipped with a stirrer in the aqueous phase section, and the stirring speed is controlled at 130 rpm. The aqueous phase containing the catalyst is circulated back to the reactor. The mass fraction of the catalyst in the circulating catalyst slurry is 2.5%. The organic phase is a toluene-cyclohexanone oxime solution, which overflows into the storage tank and is sent to the next process.

[0083] Under the above process conditions, sampling and analysis were initiated after 10 hours of operation (the conversion rate and selectivity at this point are the initial conversion rate and selectivity). Subsequently, sampling and analysis of the organic phase effluent from the catalyst separator were conducted every 10 hours. When the cyclohexanone conversion rate decreased to below 99.6%, the feeding of cyclohexanone, ammonia, and hydrogen peroxide was stopped. The conversion rate and selectivity at this point were recorded as the final conversion rate and selectivity. The unit operating time was recorded, and catalyst consumption was calculated. Gas chromatography was used for analysis. The conversion rate, selectivity, catalyst consumption, and unit operating time data are shown in Table 1.

[0084] in,

[0085] Carbonyl compound conversion rate (%) = w carbonyl compound % / (w carbonyl compound % + w oxime % × α + w reaction impurities %) × 100;

[0086]

[0087]

[0088] Where w% is the mass percentage of the corresponding component in the organic phase output of the catalyst separator; α is the molecular weight ratio of carbonyl compound and oxime; m (catalyst) is the total amount of catalyst added, g; F (carbonyl compound) is the carbonyl compound feed rate, kg / h; t is the unit operating time, h; when calculating catalyst consumption, the carbonyl compound conversion rate and oxime selectivity are the algebraic averages of the initial and final conversion rates and selectivities.

[0089] Comparative Example

[0090] Adopting such Figure 2 The reaction system shown.

[0091] Cyclohexanone, ammonia, and hydrogen peroxide are introduced into a reactor and reacted at a temperature of 89-91℃ and a pressure of 0.4MPa. The effective volume of the reactor is 300mL, and it contains TS-1 titanium-silicon molecular sieve catalyst. The feed rates are: cyclohexanone 35g / h, ammonia 8g / h, and hydrogen peroxide (35% hydrogen peroxide by mass) 40g / h. The reactants overflow from the reactor outlet into filter tank 9, which is equipped with a sintered metal filter (filtration accuracy of 10-20μm) and a stirrer. The temperature of the pipeline and filter tank must be maintained above 85℃ to prevent the solidification and precipitation of cyclohexanone oxime. The flow rate of the filtered clear liquid is controlled by a pump at 42.9g / h (accounting for 6.7% of the aqueous phase of the reaction mixture). The mass fraction of oxime in the filtered clear liquid reaches 6.3%, and oxime is prone to precipitation, leading to unstable operation of the device. The remaining liquid overflows from the filter tank, mixes with toluene, and enters extractor 10 for thorough extraction under stirring. The toluene flow rate is 85 g / h. The mixture overflows from the extractor and enters the catalyst separator. In the catalyst separator, the material is separated into an organic phase and an aqueous phase. The catalyst separator is equipped with a stirrer in the aqueous phase section, with the stirring speed controlled at 130 rpm. The aqueous phase is a slurry containing catalyst, which is recycled back to the reactor. The mass fraction of catalyst in the recycled catalyst slurry is 2.5%. The organic phase is a toluene-cyclohexanone oxime solution, which overflows into a storage tank and is sent to the next process.

[0092] Under the above process conditions, sampling and analysis were initiated after 10 hours of operation (the conversion rate and selectivity at this point are the initial conversion rate and selectivity). Subsequently, sampling and analysis of the organic phase effluent from the catalyst separator were conducted every 10 hours. When the cyclohexanone conversion rate decreased to below 99.6%, the feeding of cyclohexanone, ammonia, and hydrogen peroxide was stopped. The conversion rate and selectivity at this point were recorded as the final conversion rate and selectivity. The unit operating time was recorded, and catalyst consumption was calculated. Gas chromatography was used for analysis. The conversion rate, selectivity, catalyst consumption, and unit operating time data are shown in Table 1.

[0093] A comparison between Example 1 and the comparative example shows that the comparative example uses a method of first filtering and separating the reaction materials and then extracting the reaction products. The product oxime will pass through the filter along with the water, and its oxime content is 6.4 times that of Example 1, resulting in oxime loss. Moreover, the filtration system is unstable, the filter is prone to clogging, the device operation and control is difficult, the device operation is unstable, and the catalyst consumption is increased.

[0094] Example 2

[0095] Adopting such Figure 1 The reaction system shown.

[0096] Cyclohexanone, ammonia, and hydrogen peroxide are fed into a reactor and reacted at 89-91℃ and 0.4MPa. The effective volume of the reactor is 300mL, and it contains a TS-1 titanium-silicon molecular sieve catalyst. The feed rates are: cyclohexanone 35g / h, ammonia 8g / h, and hydrogen peroxide (35% hydrogen peroxide by mass) 40g / h. The reactants overflow from the reactor outlet and are mixed with cyclohexane before being fed into an extraction separator at a cyclohexane flow rate of 200g / h. The extraction separator contains a sintered metal filter with a filtration accuracy of 10-20μm. The mixture is stirred and extracted, while a portion of the aqueous phase is separated by the filter. A pump controls the extraction of 40.6g / h of the filtered liquid (6.3% of the aqueous phase of the reaction mixture). The oxime content in the filtered liquid is 1.16%. This filtered liquid is sent as wastewater to the next process, and the remaining mixture overflows into a catalyst separator. The material is separated into an organic phase and an aqueous phase in the catalyst separator. The catalyst separator is equipped with a stirrer in the aqueous phase section, and the stirring speed is controlled at 180 rpm. The aqueous phase containing the catalyst is circulated back to the reactor. The mass fraction of the catalyst in the circulating catalyst slurry is 2.5%. The organic phase is a cyclohexane-cyclohexanone oxime solution, which overflows into the storage tank and is sent to the next process.

[0097] Under the above process conditions, sampling and analysis were initiated after 10 hours of operation (the conversion rate and selectivity at this point are the initial conversion rate and selectivity). Subsequently, sampling and analysis of the organic phase effluent from the catalyst separator were conducted every 10 hours. When the cyclohexanone conversion rate decreased to below 99.6%, the feeding of cyclohexanone, ammonia, and hydrogen peroxide was stopped. The conversion rate and selectivity at this point were recorded as the final conversion rate and selectivity. The unit operating time was recorded, and catalyst consumption was calculated. Gas chromatography was used for analysis. The conversion rate, selectivity, catalyst consumption, and unit operating time data are shown in Table 1.

[0098] Example 3

[0099] Adopting such Figure 1 The reaction system shown.

[0100] Methyl ethyl ketone (MEK), ammonia, and hydrogen peroxide are fed into a reactor and reacted at 61-63℃ and 0.3MPa. The reactor has an effective volume of 300mL and is packed with a Ti-MWW titanium-silicon molecular sieve catalyst. The feed rates are: MEK 35g / h, ammonia 12g / h, and hydrogen peroxide (35% hydrogen peroxide by mass) 56g / h. The reactants overflow from the reactor outlet and are mixed with isooctanol before being fed into an extraction separator at a flow rate of 210g / h. The extraction separator contains a sintered metal filter with a filtration accuracy of 10-20μm. The mixture is stirred and extracted, while a portion of the aqueous phase is separated by the filter. The flow rate of the filtered clear liquid is controlled by a pump at 56.6g / h (18.5% of the aqueous phase of the reaction mixture). The oxime content in the filtered clear liquid is 1.70%. This filtered clear liquid is sent as wastewater to the next process, while the remaining mixture overflows into a catalyst separator. The material is separated into an organic phase and an aqueous phase in the catalyst separator. The catalyst separator is equipped with a stirrer in the aqueous phase section, and the stirring speed is controlled at 150 rpm. The aqueous phase containing the catalyst is circulated back to the reactor. The mass fraction of the catalyst in the circulating catalyst slurry is 5.0%. The organic phase is an isooctanol-methyl ethyl ketone oxime solution, which overflows into the storage tank and is sent to the next process.

[0101] Under the above process conditions, sampling and analysis were initiated after 10 hours of operation (the conversion rate and selectivity at this point are the initial conversion rate and selectivity). Subsequently, sampling and analysis of the organic phase effluent from the catalyst separator were conducted every 10 hours. When the methyl ethyl ketone (MEK) conversion rate decreased to below 99.0%, the feeding of MEK, ammonia, and hydrogen peroxide was stopped. The conversion rate and selectivity at this point were recorded as the final conversion rate and selectivity. The unit operating time was recorded, and catalyst consumption was calculated. Gas chromatography was used for analysis. The conversion rate, selectivity, catalyst consumption, and unit operating time data are shown in Table 1.

[0102] Example 4

[0103] Adopting such Figure 1 The reaction system shown.

[0104] Benzaldehyde, ammonia, and hydrogen peroxide are fed into a reactor and reacted at 69-71℃ and 0.2MPa. The reactor has an effective volume of 300mL and contains a Ti-MOR catalyst. The feed rates are: benzaldehyde 35g / h, ammonia 10g / h, and hydrogen peroxide (27.5% hydrogen peroxide by mass) 49g / h. The reactants overflow from the reactor outlet and are mixed with toluene before being fed into an extraction separator at a toluene flow rate of 90g / h. The extraction separator contains a sintered metal filter with a filtration accuracy of 10-20μm. The mixture is stirred and extracted, while a portion of the aqueous phase is separated by the filter. A pump controls the extraction of 49.0g / h of the filtered liquid (14.9% of the aqueous phase of the reaction mixture). The oxime content in the filtered liquid is 0.1%. This filtered liquid is sent as wastewater to the next process, and the remaining mixture overflows into a catalyst separator. The material is separated into an organic phase and an aqueous phase in the catalyst separator. The catalyst separator is equipped with a stirrer in the aqueous phase section, and the stirring speed is controlled at 70 rpm. The aqueous phase containing the catalyst is circulated back to the reactor. The mass fraction of the catalyst in the circulating catalyst slurry is 3.8%. The organic phase is a toluene-benzaldehyde oxime solution, which overflows into the storage tank and is sent to the next process.

[0105] Under the above process conditions, sampling and analysis were initiated after 10 hours of operation (the conversion rate and selectivity at this point are the initial conversion rate and selectivity). Subsequently, sampling and analysis of the organic phase effluent from the catalyst separator were conducted every 10 hours. When the benzaldehyde conversion rate decreased to below 99.0%, the feeding of benzaldehyde, ammonia, and hydrogen peroxide was stopped. The conversion rate and selectivity at this point were recorded as the final conversion rate and selectivity. The unit operating time was recorded, and catalyst consumption was calculated. Gas chromatography was used for analysis. The conversion rate, selectivity, catalyst consumption, and unit operating time data are shown in Table 1.

[0106] Example 5

[0107] The method was followed in Example 1, except that hydrogen peroxide (70% by mass) was added at a rate of 20 g / h. The rate of filtrate extraction was controlled by a pump at 19.7 g / h (3.2% of the aqueous phase of the reaction mixture), and the oxime content in the filtrate was 0.95%.

[0108] Under the above process conditions, sampling and analysis were initiated after 10 hours of operation (the conversion rate and selectivity at this point are the initial conversion rate and selectivity). Subsequently, sampling and analysis of the organic phase effluent from the catalyst separator were conducted every 10 hours. When the cyclohexanone conversion rate decreased to below 99.6%, the feeding of cyclohexanone, ammonia, and hydrogen peroxide was stopped. The conversion rate and selectivity at this point were recorded as the final conversion rate and selectivity. The unit operating time was recorded, and catalyst consumption was calculated. Gas chromatography was used for analysis. The conversion rate, selectivity, catalyst consumption, and unit operating time data are shown in Table 1.

[0109] Example 6

[0110] Adopting such Figure 1 The reaction system shown.

[0111] Cyclohexanone, ammonia, and hydrogen peroxide are fed into a reactor and reacted at 89-91℃ and 0.4MPa. The effective volume of the reactor is 300mL, and it contains a TS-1 titanium-silicon molecular sieve catalyst. The feed rates are: cyclohexanone 35g / h, ammonia 8g / h, and hydrogen peroxide (35% hydrogen peroxide by mass) 40g / h. The reactants overflow from the reactor outlet and are mixed with toluene before being fed into an extraction separator at a toluene flow rate of 120g / h. The extraction separator contains a sintered metal filter with a filtration accuracy of 10-20μm. The mixture is stirred and extracted at 50℃. Simultaneously, a portion of the aqueous phase is separated by the filter. The flow rate of the filtered clear liquid is controlled by a pump at 40.4g / h (6.3% of the aqueous phase of the reaction mixture). The oxime content in the filtered clear liquid is 0.85%. This filtered clear liquid is sent as wastewater to the next process, while the remaining mixture overflows into a catalyst separator. The material is separated into an organic phase and an aqueous phase in the catalyst separator. The catalyst separator is equipped with a stirrer in the aqueous phase section, and the stirring speed is controlled at 130 rpm. The aqueous phase containing the catalyst is circulated back to the reactor. The mass fraction of the catalyst in the circulating catalyst slurry is 2.0%. The organic phase is a toluene-cyclohexanone oxime solution, which overflows into the storage tank and is sent to the next process.

[0112] Under the above process conditions, sampling and analysis were initiated after 10 hours of operation (the conversion rate and selectivity at this point are the initial conversion rate and selectivity). Subsequently, sampling and analysis of the organic phase effluent from the catalyst separator were conducted every 10 hours. When the cyclohexanone conversion rate decreased to below 99.6%, the feeding of cyclohexanone, ammonia, and hydrogen peroxide was stopped. The conversion rate and selectivity at this point were recorded as the final conversion rate and selectivity. The unit operating time was recorded, and catalyst consumption was calculated. Gas chromatography was used for analysis. The conversion rate, selectivity, catalyst consumption, and unit operating time data are shown in Table 1.

[0113] Example 7

[0114] The method is the same as in Example 1, except that a liquid silicon-containing additive (silica sol solution) is added to make the silicon content in the aqueous phase of the reactor 300 ppm. The pump is used to control the amount of filtered liquid extracted to be 50.6 g / h (accounting for 7.8% of the mass of the aqueous phase of the reaction mixture). The mass fraction of oxime in the filtered liquid is 0.97%. The filtered liquid is sent to the next process as wastewater.

[0115] Under the above process conditions, sampling and analysis were initiated after 10 hours of operation (the conversion rate and selectivity at this point are the initial conversion rate and selectivity). Subsequently, sampling and analysis of the organic phase effluent from the catalyst separator were conducted every 10 hours. When the cyclohexanone conversion rate decreased to below 99.6%, the feeding of cyclohexanone, ammonia, and hydrogen peroxide was stopped. The conversion rate and selectivity at this point were recorded as the final conversion rate and selectivity. The unit operating time was recorded, and catalyst consumption was calculated. Gas chromatography was used for analysis. The conversion rate, selectivity, catalyst consumption, and unit operating time data are shown in Table 1.

[0116] Table 1

[0117]

[0118] As can be seen from the results in Table 1, the present invention is applicable to the ammoximation reaction of various carbonyl compounds. For the ammoximation of cyclohexanone, compared with the comparative example, the embodiments of the present invention have significantly higher cyclohexanone conversion rate and cyclohexanone oxime selectivity, and the mass fraction of oxime in the filtrate is greatly reduced. At the same time, the process is simple, can efficiently separate reaction products, wastewater and catalyst, the device operates stably, and catalyst consumption is significantly reduced.

[0119] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for the ammonoximation of a carbonyl compound, characterized in that, The method includes: (1) The reaction system containing carbonyl compounds, ammonia and hydrogen peroxide is contacted with a catalyst to carry out an ammonium oxime reaction to obtain a mixture of products; (2) The product mixture is mixed with an organic solvent, and then extracted and filtered simultaneously under stirring conditions to obtain wastewater and mixed liquid; (3) Separate the mixture to obtain an oxime-containing organic phase and a catalyst-containing aqueous phase, and return the catalyst-containing aqueous phase to step (1) to provide at least a portion of the catalyst.

2. The method according to claim 1, wherein, The carbonyl compound is selected from C3-C4. 10 aliphatic ketones, C5-C 10 Cyclic aliphatic ketones or aromatic ketones, C5-C 10 At least one of cyclic aliphatic aldehydes or aromatic aldehydes, preferably at least one of cyclohexanone, acetone, methyl ethyl ketone, cyclopentanone, acetophenone, p-hydroxyacetophenone, furfural, benzaldehyde and p-methylbenzaldehyde; Preferably, the catalyst comprises a titanium-silicon molecular sieve, wherein the titanium-silicon molecular sieve is selected from at least one of TS-1, TS-2, Ti-ZSM-5, Ti-ZSM-12, Ti-ZSM-48, Ti-β, Ti-MCM-41, Ti-MOR, Ti-MWW and Ti-SBA-15; Preferably, the reaction system in step (1) further includes a liquid silicon-containing additive, wherein the liquid silicon-containing additive is selected from inorganic silicon-containing substances and / or organic silicon-containing substances; Preferably, the inorganic silicon-containing material is silicon oxide and / or silicate, and the organic silicon-containing material is silicate ester and / or silane; Preferably, the amount of liquid silicon-containing additive used is such that the silicon concentration in the reaction system is 0.1-10000 ppm.

3. The method according to claim 1 or 2, wherein, In step (1), the molar ratio of the carbonyl compound, hydrogen peroxide, and ammonia is 1:(1-2):(1-3), preferably 1:(1-1.5):(1-2); Preferably, the hydrogen peroxide is provided by hydrogen peroxide solution, wherein the mass fraction of hydrogen peroxide in the hydrogen peroxide solution is 10-80%, preferably 20-70%; Preferably, in step (3), the mass fraction of the catalyst in the aqueous phase containing the catalyst returned from step (1) is 0.5-15%, preferably 2-10%; Preferably, the temperature of the ammonium oxime reaction is 50-100℃, more preferably 60-95℃, and the reaction pressure is 0-1MPa, more preferably 0.1-0.6MPa; Preferably, no additional organic solvent is introduced in the ammonium oxime reaction described in step (1).

4. The method according to any one of claims 1-3, wherein, In step (2), the organic solvent is selected from organic solvents that are insoluble or slightly soluble in water, preferably C6-C. 12 Alkanes, C5-C 11 Cycloalkanes, C6-C 10 At least one of aromatic hydrocarbons and C6-C8 alcohols; Preferably, the mass ratio of the organic solvent to the product mixture based on the carbonyl compound is (1-10):1, more preferably (1-6):

1.

5. The method according to any one of claims 1-4, wherein, In step (2), the extraction temperature is 20-90℃, preferably 40-80℃; Preferably, the filtration accuracy in step (2) is 0.01-50 μm, and more preferably 2-30 μm; Preferably, in step (2), the mass fraction of oxime in the wastewater is 0.01-3%, more preferably 0.01-2%.

6. The method according to any one of claims 1-5, wherein, The extraction and filtration in step (2) are carried out in an extraction separator, which is equipped with a filter; Preferably, the filter is made of ceramic or metal, and more preferably metal; Preferably, the separation in step (3) is carried out in a catalyst separator, wherein the aqueous phase section of the catalyst separator is equipped with a stirrer for stirring the aqueous phase.

7. A system for the ammonoximation reaction of a carbonyl compound, characterized in that, The reaction system includes a carbonyl compound supply unit, an ammonia supply unit, a hydrogen peroxide supply unit, an organic solvent supply unit, an ammonium oxime reaction unit, an extraction separator, and a catalyst separator; The ammonium oxime reaction unit includes at least one reactor for ammonium oxime reaction of carbonyl compound, ammonia and hydrogen peroxide from carbonyl compound supply unit, ammonia supply unit and hydrogen peroxide supply unit. The outlet of the ammonium oxime reaction unit is connected to the inlet of the extraction separator through a mixing pipeline. The extraction separator is equipped with a filter, a wastewater outlet, and a mixed liquid outlet. The mixing pipeline is provided with an organic solvent inlet connected to the organic solvent supply unit, which is used to mix the organic solvent with the ammonium oxime reaction product and then send it into the extraction separator. The feed inlet of the catalyst separator is connected to the mixed liquid outlet of the extraction separator, and is used to feed the mixed liquid from the extraction separator into the catalyst separator; the aqueous phase outlet of the catalyst separator is connected to the ammonium oxime reaction unit, and is used to return the aqueous phase containing the catalyst to the reactor.

8. The reaction system according to claim 7, wherein, The ammonium oxime reaction unit includes 1-4 reactors, preferably 1-2 reactors; Preferably, the reactor is a stirred tank reactor; Preferably, each reactor is independently connected to a hydrogen peroxide supply unit; Preferably, the reaction system further includes an additive supply unit for supplying liquid silicon-containing additives to the ammonium oxime reaction unit.

9. The reaction system according to claim 7 or 8, wherein, The outlet of the ammonium oximation reaction unit is connected to the inlet of the extraction separator via a pipeline. An organic solvent inlet is provided on the pipeline for mixing the product mixture from the ammonium oximation reaction unit with an organic solvent and then sending it into the extraction separator. Preferably, in the extraction separator, the filter is made of ceramic or metal, preferably metal; Preferably, the filtration accuracy of the filter is 0.01-50μm, and more preferably 2-30μm.

10. The reaction system according to any one of claims 1-9, wherein, The aqueous phase section of the catalyst separator is equipped with a stirrer for stirring the aqueous phase; Preferably, the catalyst separator is provided with a gas phase outlet at the top.

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