A preparation method of perfluoro-2-methyl-3-pentanone

Abstract

The invention discloses a method for preparing perfluoro-2-methyl-3-pentanone by a one-step method, wherein the method uses perfluoro-2-methyl-2-pentene as a raw material, an oxidizing gas such as oxygen or air as an oxidant, nitrogen as a carrier gas, and a self-made metal fluoride as a catalyst. The above raw materials undergo a gas phase reaction in a fluidized bed reactor to generate perfluoro-2-methyl-3-pentanone in one step. The present invention adopts a continuous gas-solid reaction process of a circulating fluidized bed reactor, shortens the traditional multi-stage reaction process to a one-step reaction, improves the efficiency of the catalytic reaction, avoids the generation of waste liquid, and solves the problem of solvent separation. Therefore, the present invention has the characteristics of simple reaction process, low cost, easy regeneration of catalyst, and high raw material conversion rate.

Description

Technical Field

[0001] The invention relates to a method for preparing perfluoro-2-methyl-3-pentanone, and in particular to a method for generating perfluoro-2-methyl-3-pentanone by reacting perfluoro-2-methyl-2-pentene vapor in a circulating fluidized bed reactor in a one-step reaction. Technical Background

[0002] Perfluoro-2-methyl-3-pentanone is one of the new generation of fire extinguishing agents. Its ODP value for ozone layer destruction is 0, and its GWP for greenhouse effect is 1. It has good environmental protection effects. In addition, perfluoro-2-methyl-3-pentanone has the advantages of low toxicity, good safety, low fire extinguishing concentration, high fire extinguishing efficiency, small impact on equipment and materials, no residue, easy storage and transportation, and wide application range. While ensuring the fire extinguishing efficiency, it solves the application problems of fluorocarbon fire extinguishing agents in the past in terms of environmental protection. Therefore, as a new type of clean fire extinguishing agent, this product has high cost performance and is a real halon substitute with broad development prospects.

[0003] At present, there are two main production processes for perfluoro-2-methyl-3-pentanone, the oxidative rearrangement of hexafluoropropylene dimer and the addition process of perfluoropropionyl fluoride and hexafluoropropylene.

[0004] Hexafluoropropylene dimer contains two isomers, namely perfluoro-4-methyl-2-pentene and perfluoro-2-methyl-2-pentene. The method for preparing perfluoro-2-methyl-3-pentanone by oxidative rearrangement of hexafluoropropylene dimer usually first prepares the corresponding epoxide by oxidizing the hexafluoropropylene dimer, and then catalytically rearranges the epoxide to obtain perfluoro-2-methyl-3-pentanone.

[0005] In patent CN1056362C, the hexafluoropropylene dimer isomerization process mainly uses a liquid phase method. This synthesis process uses hexafluoropropylene as a raw material and a fluoride as a catalyst, and the reaction is carried out in a non-protonic polar solvent. The solid catalyst is dispersed but insoluble in the organic solvent. The contact probability between the hexafluoropropylene dimer and the catalyst is low, the reaction time is long, and the solvent consumption is large.

[0006] The hexafluoropropylene dimer epoxidation process in patent CN103508983B mainly adopts a liquid phase method to prepare perfluoro-2-methyl-3-pentanone. In this synthesis process, perfluoro-2-methyl-2-pentene is used as a raw material, hydrogen peroxide or sodium hypochlorite is used as an oxidant, and acetonitrile is used as a solvent to prepare perfluoro-2-methyl-2,3-epoxypentane. In this route, the oxidation efficiency of the oxidant is low, the reaction time is long, and a large amount of waste liquid is generated.

[0007] Patent CN105198719B discloses the use of molecular oxygen or air as an oxidant, a tubular reactor, and a catalyst to react in the gas phase to prepare perfluoro-2-methyl-2,3-epoxypentane. This process has no organic solvent and solves the problem of waste liquid, but the process uses a tubular reactor and the reaction temperature is 100-300°C, the catalyst is easily deactivated, and the reaction efficiency is low.

[0008] There are two processes for rearrangement of perfluoro-2-methyl-2,3-epoxypentane to prepare perfluoro-2-methyl-3-pentanone: liquid phase method and gas phase method. Patents CN103508868B and CN105439835B disclose that in the liquid phase method, the solid fluoride catalyst is dispersed but insoluble in the organic solvent, the solid catalyst has a relatively low contact probability with perfluoro-2-methyl-2,3-epoxypentane, the reaction time is long, the product yield is low, and the amount of solvent used is large.

[0009] Patent CN103787854B discloses a process for rearrangement of perfluoro-2-methyl-2,3-epoxypentane by a gas phase method, which uses a carrier fluoride as a catalyst, a crown ether as a co-catalyst, and a tubular reactor to carry out the reaction at 100-250°C. Although the process does not use an organic solvent, the use of a tubular reactor makes the catalyst extremely easy to deactivate and the reaction efficiency is low.

[0010] 3M Company of the United States has announced a process for preparing perfluoro-2-methyl-3-pentanone by direct reaction of hexafluoropropylene with perfluoropropionyl fluoride. The process uses diethylene glycol dimethyl ether as a solvent and obtains the product by the reaction of hexafluoropropylene with perfluoropropionyl fluoride at 70°C and 1MPa. The process has good yield and selectivity, and the main difficulty lies in the preparation of perfluoropropionyl fluoride.

[0011] Patents US5684193, CN103145544, and CN105541606 disclose a method for preparing perfluoropropionyl fluoride. The process adopts a gas phase or liquid phase route, uses hexafluoropropylene oxide as a raw material, uses a liquid hydrogen fluoride amine complex, an organic base and a fluoride complex or a supported fluoride as a catalyst, and reacts at a reaction temperature of 0-200°C and 0-1MPa. The yield of perfluoropropionyl fluoride is between 85% and 95%. However, the liquid phase method has harsh reaction conditions, a complex reactor design, and contains other impurities, and is not suitable for industrial production. Since the gas phase method uses a tubular reactor, the catalyst is easily deactivated and the reaction efficiency is low.

[0012] Patent CN105198719B discloses a method for preparing perfluoro-2-methyl-3-pentanone using perfluoro-methyl-2-pentene as a raw material. However, a fixed bed is used in this method, in which the catalyst is fixedly arranged in a straight tube. When the catalyst is exhausted, it needs to be removed and replaced.

[0013] It can be seen that the gas phase method often adopts a tubular reactor, which has the problem of easy catalyst deactivation and low reaction efficiency; the liquid phase method has the problems of harsh reaction conditions, complex reactor design, many product impurities, and cannot be used for industrial mass production; and the solid fluoride catalyst has a small chance of contact with the raw materials, resulting in low reaction efficiency, long duration, low product yield, and large amount of solvent used. Summary of the invention

[0014] In view of the above problems existing in the prior art, the object of the present invention is to provide a method for timely activating a deactivated catalyst to achieve continuous reaction.

[0015] The present invention provides a method for preparing perfluoro-2-methyl-3-pentanone by using perfluoro-2-methyl-2-pentene as a raw material. In the method, an oxidizing gas and perfluoro-2-methyl-2-pentene vapor are reacted in a circulating fluidized bed reactor under the action of a catalyst to generate perfluoro-2-methyl-3-pentanone through a one-step reaction, wherein the circulating fluidized bed used in the main reactor and the regeneration reactor is of the model YC-LHC.

[0016] The chemical process of the reaction is as follows:

[0017]

[0018] The first invention of the present invention is to provide a method for preparing perfluoro-2-methyl-3-pentanone.

[0019] Furthermore, the method includes reacting an oxidizing gas with perfluoro-2-methyl-2-pentene vapor in the presence of a catalyst in a circulating fluidized bed reactor to obtain perfluoro-2-methyl-3-pentanone in a one-step process.

[0020] Furthermore, the one-step reaction process comprises:

[0021] S1, respectively loading the catalyst of the present invention into a main reactor and a regeneration reactor, and respectively introducing an oxidizing gas and a carrier gas having an oxidizing function into the main reactor and the regeneration reactor, and using the carrier gas to fluidize the catalyst;

[0022] S2, the temperature of the main reactor and the regeneration reactor are raised to 150-250°C respectively, and the supply pipeline of the preheated gasified perfluoro-2-methyl-2-pentene vapor is introduced into the loop where the main reactor is located to start the reaction. The reaction space velocity of perfluoro-2-methyl-2-pentene is 10-500h -1 ;

[0023] S3, after the reaction in the main reactor is carried out for 0.5-1.5 hours, the raw material supply pipeline is switched to the loop where the regeneration reactor is located, so that the perfluoro-2-methyl-2-pentene vapor undergoes the same reaction in the regeneration reactor, and the catalyst in the main reactor is activated at the same time, specifically, the temperature of the main reactor is first quickly raised to 300-450°C to restore the catalyst activity, and then dropped to 150-250°C to wait for subsequent reactions; the purpose of rapid heating is to save time and shorten the time of the catalyst regeneration section.

[0024] S4, after the reaction in the regeneration reactor is carried out for 0.5-1.5 hours, the raw material supply pipeline is switched to the loop where the main reactor is located, and the catalyst in the regeneration reactor is activated at the same time. The activation process is also to quickly increase the temperature of the regeneration reactor to 300-450°C, and then reduce it to 150-250°C for subsequent reaction.

[0025] The processes of S5, S3-S4 are repeated in a cycle until the reaction is completed.

[0026] In step S1, the gas velocity of introducing the oxidizing gas is 0.1L-5L / min, specifically 0.1L / min, 0.5L / min, 1L / min, 2L / min, 3L / min, 4L / min or 5L / min;

[0027] The gas velocity of the carrier gas is 0.5L-5L / min, specifically 0.5L / min, 1L / min, 2L / min, 3L / min, 4L / min or 5L / min;

[0028] The reaction space velocity of perfluoro-2-methyl-2-pentene is 10-500h -1 , specifically 10h -1 , 50h -1 , 100h -1 , 150h -1 , 200h -1 、250h -1 、300h -1 、350h -1 , 400h -1 , 450h -1 or 500h -1 , preferably 200h -1 .

[0029] The oxidizing gas with an oxidizing function includes oxygen, air or any other combustible gas.

[0030] The carrier gas includes N 2 , He, Ar, H 2 O、CO 2One or a mixture of any two or more thereof.

[0031] The volume ratio of the perfluoro-2-methyl-2-pentene vapor, the oxidizing gas and the carrier gas is (1-13):(1-12.5):5, specifically 1:1:5, 1:5:5, 1:12.5:5, 5:1:5, 5:12.5:5, 13:1:5, 13:5:5 or 13:12.5:5.

[0032] In step S2, the temperatures of the main reactor and the regeneration reactor are respectively increased to 150-250°C, specifically, the temperature of each of the main reactor and the regeneration reactor may be increased to 150°C, 200°C or 250°C.

[0033] The product obtained in step S1 is dedusted by a bag filter, and then kept at 120-150° C. and dehydrated to obtain perfluoro-2-methyl-3-pentanone. Specifically, the product can be kept at 120° C., 130° C., 140° C. or 150° C., and then dehydrated to obtain perfluoro-2-methyl-3-pentanone.

[0034] In step S3, samples are taken at 0.5 hour, 1 hour and 1.5 hours of reaction time to test the content of perfluoro-2-methyl-3-pentanone in the obtained product. When the content is lower than 90%, the above one-step reaction is repeated. When the content of perfluoro-2-methyl-3-pentanone in the product is higher than 90%, preferably 95%, the material is collected.

[0035] In step S4, after the main reactor reacts for 0.5-1.5 hours, the catalyst therein is partially deactivated, and at this time the raw material supply pipeline is switched to the loop where the regeneration reactor is located to continue the reaction, specifically for 0.5 hours, 1 hour or 1.5 hours;

[0036] In step S5, the temperature of the main reactor is rapidly increased to 300-450°C, specifically 300°C, 350°C, 400°C or 450°C, and lasts for 0.5-1 hour, specifically 0.5 hour, 0.6 hour, 0.7 hour, 0.8 hour, 0.9 hour or 1 hour; then the temperature of the main reactor is rapidly reduced to 150-250°C, specifically 150°C, 200°C or 250°C; after the reaction is carried out in the regeneration reactor for 0.5-1.5 hours, specifically 0.5 hour, 1 hour or 1.5 hours, the feed pipe is switched to the loop where the main reactor is located to continue the reaction.

[0037] Compared with the prior art, the present invention has the following advantages:

[0038] The second invention of the present invention is to provide a preparation process of the catalyst.

[0039] The preparation process of the catalyst comprises the following steps:

[0040] S1, mixing and dissolving the catalyst active component and the catalyst promoter in water, and stirring to obtain a feed liquid a;

[0041] S2, mixing and dissolving the catalyst carrier, template and binder in water, and stirring to obtain liquid b;

[0042] S3, slowly add liquid a into liquid b and stir, then pour the mixed liquid into a beater for abrasive treatment.

[0043] S4, treating the mixture obtained in S3 by spraying to obtain a shaped catalyst;

[0044] S5, calcining the shaped catalyst obtained in S4 at 400-600°C to obtain a final catalyst product.

[0045] In step S1, the catalyst active component is one of NaF, KF, CsF and RbF or a mixture of any two or more thereof; the catalyst promoter is one of Ru, Rh, Pd and Pt or a mixture of any two or more thereof;

[0046] In step S2, the catalyst carrier is one of activated carbon, kaolin and halloysite, or a mixture of any two or more thereof; the template is one of anionic, cationic, zwitterionic and non-ionic surfactants, or a mixture of any two or more thereof; the binder is one of nitric acid, hydrochloric acid and acetic acid, or a mixture of any two or more thereof.

[0047] The mass fractions of the above components are: 1-20 parts of catalyst active components, 0.1-5 parts of catalyst promoters, 15-20 parts of catalyst carriers, 1-5 parts of templates, and trace amounts of binders, where "trace amounts" means effective amounts for bonding, such as 0-1 parts.

[0048] In step S4, the particle size of the shaped catalyst is 50-100 microns, specifically 50 microns, 60 microns, 70 microns, 80 microns, 90 microns or 100 microns.

[0049] In step S5, the preliminarily formed catalyst obtained in S3 is calcined at 400-500°C for 4-12 hours. The specific calcination temperature can be 400°C, 450°C or 500°C, and the calcination time can be 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 11 hours or 12 hours.

[0050] The invention uses perfluoro-2-methyl-2-pentene as a raw material to prepare perfluoro-2-methyl-3-pentanone, adopts an oxidizing gas with an oxidizing function and perfluoro-2-methyl-2-pentene steam to carry out a gas phase reaction in a circulating fluidized bed reactor under the action of a self-made catalyst, and adopts a one-step method to prepare perfluoro-2-methyl-3-pentanone.

[0051] Compared with the prior art, the present invention has the following technical effects:

[0052] (1) Existing fixed bed or tubular catalysts have low mechanical strength, low activity and short reaction life. The present invention adopts a continuous gas-solid reaction process of a circulating fluidized bed reactor to shorten the traditional multi-stage reaction process to a one-step reaction. By using the main reactor and the regeneration reactor in a coordinated and cyclic manner, the reaction can be continuously carried out and the catalyst can be continuously regenerated, thereby improving the reaction efficiency.

[0053] (2) At the same time, the strength, reaction activity and reaction life of the catalyst are improved by the homemade catalyst, and the conversion rate of the raw material and the selectivity of perfluorohexanone are improved. Specifically, when the content of perfluoro-2-methyl-3-pentanone in the reaction product is less than 90%, the reaction cycle is carried out, and the recycling of the catalyst and the solvent system can be realized, which further improves the efficiency of continuous synthesis. The raw material perfluoro-2-methyl-2-pentene and the oxidizing gas undergo the above-mentioned recycling and reaction process in the circulating fluidized bed reactor, and finally the rapid conversion of the raw material is achieved and the raw material conversion rate is greater than 98%, and the yield of the product perfluoro-2-methyl-3-pentanone is more than 95%.

[0054] (3) A catalyst regeneration system is used in the manufacturing process to prepare fluoride and additives into spherical catalysts through spray molding technology. The catalyst has the properties of high specific surface area, large contact area with raw materials, large active component content and high mechanical strength. When the catalyst is exhausted, the spherical container floats out in a circulation manner, so that it can be quickly filled to achieve continuous reaction, and at the same time, the online regeneration of the deactivated catalyst is achieved, which greatly improves the efficiency of the catalyst. The manufacturing process is simple, low cost, easy catalyst regeneration, and high raw material conversion rate.

[0055] (4) In the process, no organic solvent or oxidant such as sodium hypochlorite is used. The catalyst and solvent used in the reaction can be separated and processed in the product purification and separation process and directly reused, thereby avoiding the generation of waste liquid, solving the problem of solvent separation, reducing the raw material cost of the present invention, and having a significant environmental protection effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 Schematic diagram of the preparation steps of perfluoro-2-methyl-3-pentanone provided in Example 1. DETAILED DESCRIPTION

[0057] The term "activation" may be a process conventionally recognized by those skilled in the art as increasing catalytically active sites in a catalyst.

[0058] The term "space velocity" refers to the ratio of the amount of feedstock entering the reactor per hour to the volume of catalyst in the reactor. The calculation formula is space velocity = standard volume flow rate of feedstock entering the reactor (m 3 / h) / volume of catalyst in reactor (m 3 ).

[0059] The term "active component of a catalyst" refers to a substance that can interact with reactants to change the speed at which a chemical reaction approaches equilibrium (but does not change the position of the chemical reaction equilibrium) without itself appearing in the product;

[0060] The term "catalyst promoter" refers to an element or component in a catalyst that has a minor effect on the catalytic performance and selectivity of the catalyst. Specifically, it is a small amount of substance added to the catalyst, which is an auxiliary component of the catalyst. It itself has no activity or very low activity. However, after adding it to the catalyst, it can change the chemical composition, chemical structure, ion valence, acidity and alkalinity, lattice structure, surface structure, pore structure, dispersion state, continuous strength, etc. of the catalyst, thereby improving the activity, selectivity, stability and life of the catalyst. In addition, the catalyst promoter can also improve the performance of the carrier, such as improving the thermal stability of the carrier.

[0061] The term "binder" refers to a substance that enhances the mechanical strength of the catalyst, has a strong resistance to metal contamination and a high coke selectivity, and can transfer the active substances of the reaction, providing the catalyst with medium and large pores to improve the diffusion performance.

[0062] The term "template" is a structure-directing agent, and its dosage and purity will affect the performance of the catalyst. The role of the template is to have a self-assembly effect in the process of preparing the catalyst, so that the catalyst inorganic matter grows around the template during the precipitation process, so that the catalyst particles have certain microporous or mesoporous characteristics, thereby increasing the specific surface area of ​​the catalyst.

[0063] Unless otherwise defined, all technical terms and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present application, and the terms used herein in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The reagents and instruments used herein are all commercially available, and the characterization means involved can refer to the relevant descriptions in the prior art, which will not be repeated herein.

[0064] The “several” mentioned in the present invention includes two, multiple or all situations, which will not be described in detail below.

[0065] In the present invention, the conditions and methods of the reaction may be conventional conditions and methods for such reactions in the art.

[0066] In order to make the purpose, technical solution and advantages of the present application more clear, the present application is further described in detail below. However, it should be understood that the description here is only used to explain the present application and is not used to limit the scope of the present application.

[0067] Example 1

[0068] This embodiment provides a method for preparing perfluoro-2-methyl-3-pentanone by a one-step reaction method, and a method for preparing the catalyst used therein.

[0069] Figure 1 The schematic diagram of the preparation steps of perfluoro-2-methyl-3-pentanone provided in this embodiment. The method comprises the following steps:

[0070] In a first aspect, a method for preparing perfluoro-2-methyl-3-pentanone by a one-step reaction method comprises:

[0071] 1. The self-made catalyst is loaded into the main reactor and the regeneration reactor respectively, and the oxidizing gas and carrier gas with oxidation function are introduced into the main reactor and the regeneration reactor.

[0072] The role of the oxidizing gas with oxidation function is to support combustion, and it can be air, oxygen or any gas with combustion support; the role of the carrier gas is to realize the circulation of the catalyst, that is, the fluidization of the catalyst. Conventional fluidizing gases can play the role of fluidization, abrasion and classification, such as air, nitrogen, water vapor, helium, etc. It can be one of the conventional fluidizing gases or a mixture of concentrated gases, preferably N 2 , He, Ar, H 2 O、CO 2 The use of carrier gas improves the fluidity of the reactor's fluidization, circulation and regeneration process, improves the operational stability, and has important guiding significance for the long-term recycling of the reactor. At the same time, the process has the characteristics of simple operation, good classification effect, and strong operational continuity.

[0073] In some embodiments, the gas velocity of the oxidizing gas is 0.1-5 L / min, specifically 0.1 L / min, 0.5 L / min, 1 L / min, 2 L / min, 3 L / min, 4 L / min or 5 L / min.

[0074] In some embodiments, the gas velocity of the carrier gas is 0.5-5 L / min, specifically 0.5 L / min, 1 L / min, 2 L / min, 3 L / min, 4 L / min or 5 L / min.

[0075] In some embodiments, the volume ratio of the oxidizing gas to the carrier gas is (0.2-2.5):1, specifically 0.2:1, 0.5:1, 1:1, 1.5:1, 2:1 or 2.5:1.

[0076] 2. Primary reaction:

[0077] The temperatures of the main reactor and the regeneration reactor are respectively increased to 150-250° C., which is the optimal range for the gas phase reaction of perfluoro-2-methyl-2-pentene determined after repeated practice of the present invention.

[0078] Since perfluoro-2-methyl-2-pentene is a liquid at room temperature, it must be preheated and vaporized before entering the reactor. After preheating perfluoro-2-methyl-2-pentene to 150-250°C, the generated perfluoro-2-methyl-2-pentene vapor is introduced into the main reactor to undergo a gas phase reaction. The chemical formula of the gas phase reaction is as follows:

[0079]

[0080] The main reactor and regeneration reactor used in the present invention are both fluidized bed reactors. Figure 1 As shown. The outlet of the main reactor on the left is connected with a pipeline, which transports the product obtained by the reaction through dust removal, heat preservation, dehydration and drying processes to obtain perfluoro-2-methyl-3-pentanone (as shown by the arrow in the figure). The inlet of the main reactor is connected with a supply line of perfluoro-2-methyl-2-pentene. Similarly, the outlet of the regeneration reactor on the right is also connected with a pipeline for conveying the reaction product, and its inlet is connected with a supply line of perfluoro-2-methyl-2-pentene. In this way, two left and right loops (i.e., two closed loops) as shown in the figure are formed, and the above reaction is carried out alternately in the two loops. The process is as follows:

[0081] The supply pipeline of the preheated raw material perfluoro-2-methyl-2-pentene vapor is introduced into the loop where the main reactor is located to start the reaction. The reaction space velocity of the perfluoro-2-methyl-2-pentene vapor is (10-500) h -1 , specifically 10h -1 , 50h -1 , 100h -1 , 200h -1 、300h -1 , 400h -1 or 500h -1 The space velocity here refers to the ratio of the amount of raw materials entering the reactor per hour to the volume of the catalyst in the reactor. The specific formula is space velocity = standard volume flow rate of raw materials entering the reactor (m 3 / h) / volume of catalyst in reactor (m 3). Therefore, the volume ratio of perfluoro-2-methyl-2-pentene to the catalyst in the reactor is (10-500):1, specifically 10:1, 50:1, 100:1, 150:1, 200:1, 300:1, 400:1 or 500:1.

[0082] The amount of catalyst used in the present invention has an impact on the reaction. The reaction yield increases with the increase in the amount of catalyst used; however, when the catalyst reaches a certain amount, the yield is not significantly improved. Therefore, after comprehensively considering the reaction yield and cost, the space velocity of perfluoro-2-methyl-2-pentene is selected to be (10-500) h -1 When , the reaction yield is the highest and the cost does not increase significantly.

[0083] In the present invention, the volume ratio of perfluoro-2-methyl-2-pentene vapor, oxidizing gas and carrier gas is (1-13):(1-12.5):5, specifically 1:1:5, 1:5:5, 1:12.5:5, 5:1:5, 5:12.5:5, 13:1:5, 13:5:5, 13:12.5:5 or any value within the above ratio range.

[0084] The reaction temperature in the present invention has an influence on the reaction conversion rate. If the temperature is too low, the conversion rate of perfluoro-2-methyl-2-pentene is relatively low. After reaching a certain temperature, the conversion rate is not significantly improved by further increasing the temperature. Considering the conversion rate and energy consumption comprehensively, the reaction temperature in the present invention is 150-250°C, specifically 150°C, 200°C or 250°C, preferably 200°C.

[0085] Similarly, the reaction time in the present invention also affects the reaction conversion rate. After many practices, the reaction time is selected to be 0.5-1.5 hours, preferably 1 hour, at which time the reaction conversion rate and reaction efficiency reach a better balance.

[0086] In the present invention, the reaction product is subjected to conventional dust removal through a dust removal bag to remove dust mixed in the product, and then kept warm at 120-150° C., specifically 120° C., 130° C., 140° C. or 150° C.; and then dehydrated to obtain perfluoro-2-methyl-3-pentanone.

[0087] 3. Circular reaction:

[0088] After the above reaction is carried out for 0.5-1.5 hours, the content of perfluoro-2-methyl-3-pentanone in the product is measured. When the content of perfluoro-2-methyl-3-pentanone in the obtained product is lower than the expected value, for example, 90%, the raw material supply pipeline is switched to the loop where the regeneration reactor is located, so that the perfluoro-2-methyl-2-pentene vapor undergoes the same reaction in the regeneration reactor, and the catalyst in the main reactor is activated at the same time.

[0089] In some embodiments, after the reaction is carried out in one of the main reactor and the regeneration reactor for 0.5-1.5 hours, such as 0.5 hours, 1 hour or 1.5 hours, the catalyst in the reactor pipeline is deactivated or partially deactivated. In order to restore its activity and maximize the reaction efficiency, the feed pipeline is switched to the loop where the other of the two reactors is located to continue the reaction; at the same time, the temperature of the reactor where the catalyst is deactivated is rapidly increased to 300-450°C, such as 300°C, 350°C, 400°C or 450°C, so as to regenerate and activate the catalyst at this high temperature. The purpose of rapid temperature increase is to save time and shorten the time of the catalyst regeneration section. This regeneration and activation process lasts for 0.5-1 hour, specifically 0.5 hours, 0.6 hours, 0.7 hours, 0.8 hours, 0.9 hours or 1 hour, until the catalyst in the reactor has been regenerated and activated.

[0090] The deactivation of the catalyst in the above process is mainly caused by the reduction and blockage of the catalyst surface area due to carbon deposition, the reduction of the surface area and the reduction of catalytic activity due to the pollution of precious metals, and the reduction of the catalyst active sites due to the adsorption of poisons. The regeneration and activation of the catalyst is mainly the fluidized bed carbonization method, which is to carbonize the catalyst back and forth 3-4 times in the natural air of the fluidized bed, with the temperature from low to high, and the highest temperature not exceeding 450℃, to remove the coke.

[0091] After the catalyst is activated, the temperature of the reactor in which the catalyst is located needs to be lowered to the original reaction temperature, that is, between 150-250°C, specifically 150°C, 200°C or 250°C, so as to prepare for the continued reaction.

[0092] The above reaction occurs alternately in the main reactor and the regeneration reactor to achieve the continuity of the reaction, until the content of perfluoro-2-methyl-3-pentanone in the product is higher than the expected value, for example, 90%-100%, preferably 95%, and then the material is collected. In the actual production process, conventional distillation operations in the art can be used according to market needs to obtain products with higher content.

[0093] In a second aspect, the method for preparing the catalyst in the above process comprises the following steps:

[0094] 1. Mixing catalyst active components, catalyst promoter, catalyst carrier, template, binder and water to obtain a mixture;

[0095] In some embodiments, a catalyst active component, a catalyst promoter, a catalyst carrier, a template, an appropriate amount of a binder and water are mixed to obtain a mixture, wherein the mass fractions of each component are: 1-20 parts of the catalyst active component, 0.1-5 parts of the catalyst promoter, 15-20 parts of the catalyst carrier, 1-5 parts of the template, and a trace amount of the binder, wherein "trace amount" means an effective amount for bonding, for example 0-1 part.

[0096] The catalyst active component may be a commonly used component in the catalyst field, preferably one of NaF, KF, CsF and RbF or a mixture of any two or more thereof; for example, NaF, KF, CsF, RbF, a mixture of NaF and KF, a mixture of CsF and RbF, etc. When the active component is a mixture of two or more, the mass ratio between the components has no fixed range and can be changed according to the reaction conditions; the raw material providing the active component may be a metal monomer of the above elements, or a nitrate thereof.

[0097] The catalyst promoter may be a promoter conventionally used in the catalyst field for improving the catalytic activity or selectivity of the catalyst, preferably one of Ru, Rh, Pd and Pt or a mixture of any two or more thereof;

[0098] The catalyst carrier may be a conventional carrier, preferably one of activated carbon, kaolin and halloysite or a mixture of any two or more thereof; the wall thickness of the catalyst carrier may be conventional in the art, preferably 0.1-0.2 mm, more preferably 0.15-0.18 mm. The shape of the catalyst carrier may be conventional in the art, preferably one or more of powder, granule, rod and honeycomb, more preferably honeycomb;

[0099] The binder is one of nitric acid, hydrochloric acid and acetic acid or a mixture of any two or more thereof;

[0100] The template agent is one or a mixture of any two or more of anionic, cationic, zwitterionic and nonionic surfactants; the role of the template agent is to have a self-assembly effect in the process of preparing the catalyst, so that the catalyst inorganic matter grows around the template agent during the precipitation process, so that the catalyst particles have certain microporous or mesoporous characteristics, thereby increasing the specific surface area of ​​the catalyst.

[0101] The catalyst active components and catalyst promoters can be loaded on the catalyst carrier in various ways, such as the active components are in the inner layer of the carrier and the promoters are in the outer layer of the carrier, or the active components are in the outer layer of the carrier and the promoters are in the inner layer of the carrier, or the active components and promoters are evenly distributed in various parts of the carrier.

[0102] 2. Abrasive and pulping treatment:

[0103] The mixture obtained in the above step 1 is subjected to grinding and pulping treatment to prepare a spray-formed slurry, and the raw material liquid is spray-formed by a spray-forming device to prepare a formed catalyst with a particle size of 50-100 microns.

[0104] In some embodiments, the mixture is poured into a grinder for grinding for 15-30 minutes to prepare a spray-formed slurry, and the grinding time may be 15 minutes, 20 minutes, 25 minutes or 30 minutes.

[0105] In some embodiments, the particle size of the shaped catalyst is 50-100 microns, specifically 50 microns, 60 microns, 70 microns, 80 microns, 90 microns or 100 microns;

[0106] 3. Roasting to obtain the finished product:

[0107] The shaped catalyst obtained in step 2 is calcined at 400-500°C for 4-12 hours. The specific calcination temperature can be 400°C, 450°C or 500°C, and the calcination time can be any value of 4-12 hours, for example, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 11 hours or 12 hours to obtain the final catalyst.

[0108] Example 2

[0109] This embodiment provides a specific preparation process of the above catalyst.

[0110] S1, dissolve 114 g of potassium fluoride, 0.64 g of chloroplatinic acid, and 1.1 g of hexadecyltrimethylammonium bromide in 1.2 L of water, and stir to obtain a feed solution a.

[0111] S2, dissolve 358 g of kaolin and 12 g of nitric acid in 1.2 L of water, stir, and obtain liquid b.

[0112] S3, slowly add liquid a into liquid b, stir for 0.5 hour, then pour the mixture into a beater and grind for 0.5 hour.

[0113] S4, the inlet temperature of the spray tower is set to 150°C, the speed of the spray wheel is set to 10000 rpm, and the ground raw material is introduced into the spray tower at a feed rate of 0.8 L / min.

[0114] S5, calcining the prepared catalyst in a muffle furnace at 500° C. for 4 hours to obtain the catalyst.

[0115] Example 4

[0116] This embodiment provides a specific preparation process of the above catalyst.

[0117] S1, dissolve 137g of cesium fluoride, 0.84g of palladium chloride and 2.4g of P123 in 1.5L of water, stir to obtain liquid a.

[0118] S2, dissolve 364 g of halloysite and 15.4 g of hydrochloric acid in 1.5 L of water, stir, and obtain liquid b.

[0119] S3, slowly add liquid a into liquid b, stir for 0.5 hour, then pour the mixture into a beater and grind for 0.5 hour.

[0120] S4, the inlet temperature of the spray tower is set to 200°C, the spray wheel speed is set to 9000 rpm, and the ground raw materials are introduced into the spray tower at a feed rate of 1 L / min.

[0121] S5, calcining the prepared catalyst in a muffle furnace at 400° C. for 12 hours to obtain the catalyst.

[0122] Example 5

[0123] This embodiment provides a specific preparation process of the above catalyst.

[0124] S1, dissolve 184g of sodium fluoride, 1.17g of rhodium chloride and 1.89g of sodium dodecylbenzene sulfonate in 1.9L of water, stir to obtain feed liquid a.

[0125] S2, dissolve 364 g of pseudo-boehmite and 20.1 g of acetic acid in 1.9 L of water, stir, and obtain liquid b.

[0126] S3, slowly add liquid a into liquid b, stir for 0.5 hour, then pour the mixture into a beater and grind for 0.5 hour.

[0127] S4, the inlet temperature of the spray tower is set to 200°C, the speed of the spray wheel is set to 10000 rpm, and the ground raw material is introduced into the spray tower at a feed rate of 0.6 L / min.

[0128] S5, calcining the prepared catalyst in a muffle furnace at 400° C. for 5 hours to obtain the catalyst.

[0129] Example 6

[0130] This embodiment provides a specific method for preparing perfluoro-2-methyl-3-pentanone by a one-step reaction process.

[0131] 108 g of the catalyst prepared in Example 3 was loaded into each of the 500 ml circulating fluidized bed main regeneration reactors, and oxygen was introduced at a rate of 0.7 L / min; a carrier gas N 2 , speed is 2.4L / min.

[0132] The temperatures of the main reactor and the regeneration reactor were raised to 150°C respectively.

[0133] Perfluoro-2-methyl-2-pentene was introduced into the main reactor at a reaction space velocity of 50 h -1 The samples were collected and analyzed after 0.5 hour, 1 hour and 1.5 hours of reaction.

[0134] Subsequently, the raw materials were switched to enter the regeneration reactor, and the products were sampled and analyzed after the reaction lasted for 0.5 hours, 1 hour, and 1.5 hours.

[0135] After switching the reactor, the temperature of the main reactor was quickly raised to 300°C, kept at that temperature for 1 hour, and then quickly cooled to 150°C.

[0136] The raw material supply pipeline was switched from the loop where the regeneration reactor was located to the loop where the main reactor was located, and sampling and analysis were performed after 0.5 hour, 1 hour and 1.5 hours of reaction respectively.

[0137] Table 1 Main regeneration reactor raw material conversion rate and product yield

[0138]

[0139] Example 7

[0140] This embodiment provides a method for preparing perfluoro-2-methyl-3-pentanone by a one-step reaction process.

[0141] 134 g of catalyst A was loaded into each circulating fluidized bed main regeneration reactor with a volume of 500 ml, and air was introduced at a rate of 2.3 L / min, and water vapor was introduced at a rate of 3.7 L / min.

[0142] The temperature of the main reactor and the regeneration reactor was raised to 200°C.

[0143] The raw material supply pipeline of perfluoro-2-methyl-2-pentene was switched to the loop where the main reactor was located, and the reaction space velocity was 200h -1 The samples were collected and analyzed after 0.5 hour, 1 hour and 1.5 hours of reaction.

[0144] Subsequently, the raw material supply pipeline was switched to the loop where the regeneration reactor was located, and sampling and analysis were performed after the reaction lasted for 0.5 hour, 1 hour and 1.5 hours.

[0145] After the switch, the temperature of the main reactor was quickly raised to 500°C, kept at that temperature for 1 hour, and then quickly cooled to 200°C.

[0146] The raw material supply pipeline was switched from the loop where the regeneration reactor was located to the loop where the main reactor was located, and sampling and analysis were performed after 0.5 hour, 1 hour and 1.5 hours of reaction.

[0147] Table 2 Main regeneration reactor raw material conversion rate and product yield

[0148]

[0149] Example 8

[0150] This embodiment provides a method for preparing perfluoro-2-methyl-3-pentanone by a one-step reaction process.

[0151] 129 g of catalyst B was loaded into each of the 500 ml circulating fluidized bed main regeneration reactors, and oxygen was introduced at a rate of 4.4 L / min; N 2 , speed is 2.8L / min.

[0152] The temperature of the main reactor and the regeneration reactor was raised to 300°C. The raw material supply pipeline of perfluoro-2-methyl-2-pentene was switched to the loop where the main reactor was located, and the reaction space velocity was 480h -1 The samples were collected and analyzed after 0.5 hour, 1 hour and 1.5 hours of reaction.

[0153] The raw material supply pipeline was then switched to the pipeline where the regeneration reactor was located, and sampling and analysis were performed after 0.5 hour, 1 hour and 1.5 hours of reaction.

[0154] After the switch, the temperature of the main reactor was quickly raised to 400°C, kept at that temperature for 1 hour, and then quickly cooled to 300°C.

[0155] The raw material supply pipeline was switched from the regeneration reactor to the loop where the main reactor was located, and sampling and analysis were performed after 0.5 hour, 1 hour and 1.5 hours of reaction.

[0156] Table 3 Main regeneration reactor raw material conversion rate and product yield

[0157]

[0158]

[0159] Example 9

[0160] This embodiment provides a method for preparing perfluoro-2-methyl-3-pentanone by a one-step reaction process.

[0161] 210 g of catalyst C was loaded into each circulating fluidized bed main regeneration reactor with a volume of 500 ml, and air was introduced at a rate of 3.7 L / min; He was introduced at a rate of 1.3 L / min.

[0162] The temperature of the main reactor and the regeneration reactor was raised to 250°C.

[0163] The raw material supply pipeline of perfluoro-2-methyl-2-pentene was switched to the loop where the main reactor was located, and the reaction space velocity was 310h-1 The samples were collected and analyzed after 0.5 hour, 1 hour and 1.5 hours of reaction.

[0164] Subsequently, the raw material supply pipeline was switched to the loop where the regeneration reactor was located, and sampling and analysis were performed after the reaction lasted for 0.5 hour, 1 hour and 1.5 hours.

[0165] After the switch, the temperature of the main reactor was quickly raised to 400° C., kept at this temperature for 1 hour, and then quickly cooled to 250° C. The raw material supply pipeline was switched to the loop where the main reactor was located, and sampling and analysis were performed after 0.5 hour, 1 hour, and 1.5 hours of reaction.

[0166] Table 4 Main regeneration reactor raw material conversion rate and product yield

[0167]

[0168] Comparative Example 1

[0169] This comparative example provides a method for preparing perfluoro-2-methyl-3-pentanone by a one-step reaction process.

[0170] 210 g of catalyst C was loaded into each circulating fluidized bed main regeneration reactor with a volume of 500 ml, and air was introduced at a rate of 3.7 L / min; He gas was introduced at a rate of 1.3 L / min.

[0171] The temperature of the main reactor and the regeneration reactor was raised to 120°C to prepare for the reaction;

[0172] The raw material supply pipeline of perfluoro-2-methyl-2-pentene was switched to the loop where the main reactor was located, and the reaction space velocity was 310h -1 The samples were collected and analyzed after 0.5 hour, 1 hour and 1.5 hours of reaction.

[0173] Subsequently, the raw material supply pipeline was switched to the loop where the regeneration reactor was located, and sampling and analysis were performed after the reaction lasted for 0.5 hour, 1 hour and 1.5 hours.

[0174] After the switch, the temperature of the main reactor was quickly raised to 400° C., kept at this temperature for 1 hour, and then quickly cooled to 250° C. The raw material supply pipeline was switched to the loop where the main reactor was located, and sampling and analysis were performed after 0.5 hour, 1 hour, and 1.5 hours of reaction.

[0175] Table 5 Main regeneration reactor raw material conversion rate and product yield

[0176]

[0177] The reaction temperature of the one-step reaction in the above process is 120° C., which is lower than the optimal temperature range of 150-250° C. The results show that the conversion rate of the raw material is low and the yield of the product is also reduced, indicating that the lower reaction temperature is not conducive to the reaction.

[0178] Comparative Example 2

[0179] This comparative example provides a method for preparing perfluoro-2-methyl-3-pentanone by a one-step reaction process.

[0180] 210 g of catalyst C was loaded into each circulating fluidized bed main regeneration reactor with a volume of 500 ml, and air was introduced at a rate of 3.7 L / min; He was introduced at a rate of 1.3 L / min.

[0181] The temperature of the main reactor and the regeneration reactor was raised to 280°C to prepare for the reaction;

[0182] The raw material supply pipeline of perfluoro-2-methyl-2-pentene was switched to the loop where the main reactor was located, and the reaction space velocity was 310h -1 The samples were collected and analyzed after 0.5 hour, 1 hour and 1.5 hours of reaction.

[0183] Subsequently, the raw material supply pipeline was switched to the loop where the regeneration reactor was located, and sampling and analysis were performed after the reaction lasted for 0.5 hour, 1 hour and 1.5 hours.

[0184] After the switch, the temperature of the main reactor was quickly raised to 400° C., kept at this temperature for 1 hour, and then quickly cooled to 250° C. The raw material supply pipeline was switched to the loop where the main reactor was located, and sampling and analysis were performed after 0.5 hour, 1 hour, and 1.5 hours of reaction.

[0185] Table 6 Main regeneration reactor raw material conversion rate and product yield

[0186]

[0187] The reaction temperature of the one-step reaction in the above process is 280°C, which is higher than the optimal temperature range of 150-250°C. The results show that the conversion rate of the raw material increases, but the yield of the product decreases significantly, indicating that when the reaction temperature exceeds the optimal range, the conversion rate of the raw material can be effectively improved, but the excessively high reaction temperature causes the product to decompose, thereby reducing the yield.

[0188] Comparative Example 3

[0189] This comparative example provides a method for preparing perfluoro-2-methyl-3-pentanone by a one-step reaction process.

[0190] 210 g of catalyst C was loaded into each circulating fluidized bed main regeneration reactor with a volume of 500 ml, and air was introduced at a rate of 3.7 L / min; He was introduced at a rate of 1.3 L / min.

[0191] The temperature of the main reactor and the regeneration reactor was raised to 250°C to prepare for the reaction;

[0192] The raw material supply pipeline of perfluoro-2-methyl-2-pentene was switched to the loop where the main reactor was located, and the reaction space velocity was 310h -1 The samples were collected and analyzed after 0.5 hour, 1 hour and 1.5 hours of reaction.

[0193] Subsequently, the raw material supply pipeline was switched to the loop where the regeneration reactor was located, and sampling and analysis were performed after the reaction lasted for 0.5 hour, 1 hour and 1.5 hours.

[0194] After the switch, the temperature of the main reactor was quickly raised to 480°C to restore the catalyst activity, and after 1 hour of heat preservation, the temperature was quickly lowered to 250°C. The raw material supply pipeline was switched to the loop where the main reactor was located, and sampling and analysis were performed after 0.5 hour, 1 hour and 1.5 hours of reaction.

[0195] Table 7 Main regeneration reactor raw material conversion rate and product yield

[0196]

[0197] The above process rapidly raises the temperature to 480°C to restore the activity of the catalyst, while the optimal regeneration activation temperature range of the catalyst proposed in the present invention is 300-450°C. After the catalyst exceeds the optimal regeneration activation temperature, the mechanical strength of the catalyst decreases, and the active components on the catalyst surface are lost during the catalyst regeneration process, thereby reducing the performance of the catalyst.

[0198] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A method for preparing perfluoro-2-methyl-3-pentanone, characterized in that: The method comprises: subjecting the raw material perfluoro-2-methyl-2-pentene to a catalyst to obtain perfluoro-2-methyl-3-pentanone through a one-step reaction; Both the main reactor and the regeneration reactor are fluidized bed reactors; The one-step reaction comprises: S1: introducing the catalyst, the oxidizing gas with an oxidizing function and the carrier gas into the main reactor and the regeneration reactor respectively; S2: raising the temperature of the main reactor and the regeneration reactor to between 150-250° C., and passing the supply pipeline of the raw material perfluoro-2-methyl-2-pentene into the main reactor for reaction; S3: After the reaction is carried out in the main reactor for 0.5-1.5 hours, the supply pipeline of the raw material is switched to the regeneration reactor, so that the perfluoro-2-methyl-2-pentene vapor undergoes the same reaction in the regeneration reactor; and the catalyst in the main reactor is activated at the same time; S4: When the reaction is carried out in the regeneration reactor for 0.5-1.5 hours, the raw material supply pipeline is switched to the main reactor, and the catalyst in the regeneration reactor is activated at the same time; S5: The process of S3-S4 is repeated until the reaction is completed; The process of activating the catalyst in the main reactor / regeneration reactor includes raising the temperature of the main reactor / regeneration reactor to 300-450° C. and then lowering it to 150-250° C.; The active component of the catalyst is one of NaF, KF, CsF and RbF or a mixture of any several thereof; the auxiliary agent of the catalyst is one of Ru, Rh, Pd and Pt or a mixture of any several thereof.

2. The preparation method according to claim 1, characterized in that: The reaction space velocity of perfluoro-2-methyl-2-pentene in the main reactor and the regeneration reactor is 10-500h -1 .

3. The preparation method according to claim 1, characterized in that: In step S1, the oxidizing gas is oxygen or air; the carrier gas is one or a mixture of any of N2, He, Ar, H2O and CO2.

4. The preparation method according to claim 1, characterized in that: The perfluoro-2-methyl-2-pentene needs to be preheated and vaporized into steam before the reaction, and the volume ratio of the perfluoro-2-methyl-2-pentene steam, the oxidizing gas and the carrier gas is (1-13):(1-12.5):

5.

5. The preparation method according to claim 1, characterized in that: The method for preparing the catalyst in step S1 comprises: S1, mixing and dissolving the catalyst active component and the catalyst promoter in water, and stirring to obtain a feed liquid a; S2, mixing and dissolving the catalyst carrier, template and binder in water, and stirring to obtain liquid b; S3, adding liquid a to liquid b to obtain a mixed liquid, and subjecting the mixed liquid to abrasive treatment; S4, spraying the product obtained in S3 to obtain a formed catalyst; S5, calcining the shaped catalyst obtained in S4 at 400-600°C to obtain the final catalyst.

6. The preparation method according to claim 5, characterized in that: The catalyst carrier is one of activated carbon, kaolin and halloysite or a mixture of any of them; the template is one of anionic, cationic, zwitterionic and non-ionic surfactants or a mixture of any of them; the binder is one of nitric acid, hydrochloric acid and acetic acid or a mixture of any of them.

7. The preparation method according to claim 1, characterized in that: The mass proportions of the various components in the catalyst are: 1-20 parts of catalyst active components, 0.1-5 parts of catalyst promoters, 15-20 parts of catalyst carriers, 1-5 parts of template agents and a trace amount of binder.

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