Fluorination reaction catalyst as well as preparation method and application thereof
A novel fluorination catalyst was prepared by using a combination of modified alumina support and active metal elements such as Cr and Ni, which solved the problem of short lifespan of existing catalysts and achieved efficient and regenerable fluorination reaction.
Patent Information
- Application Number
- CN202511355155.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-22
- Publication Date
- 2025-12-30
AI Technical Summary
Existing catalysts have short lifespans in fluorination reactions, requiring frequent replacement and regeneration, which leads to increased production efficiency and costs, and existing improvement methods have limited effectiveness.
A novel fluorination catalyst was prepared by using alumina or modified alumina containing alumina or modified metal elements as a support and combining it with active metal elements such as Cr and Ni. The catalyst was prepared through a specific impregnation and heat treatment process.
It extends catalyst lifetime, improves reaction efficiency and product selectivity, reduces by-product formation, and the catalyst is regenerable with good activity recovery.
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Figure CN121222437A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the field of catalysis, and more particularly provides a catalyst and a preparation method thereof, and a method for fluorination of chloroalkanes using the catalyst. BACKGROUND
[0002] Fluorocarbons (e.g. fluoroolefins, fluoroalkanes, etc.) have extremely wide applications in various fields, such as being used as monomer raw materials or intermediates to synthesize fluoropolymers with excellent properties, and being used to replace ozone-depleting substances (ODS), etc. For example, HFO-1234yf (2,3,3,3-tetrafluoropropene) is widely used as a substitute for ODS reagents in the fields of refrigerants, fire extinguishing agents, foaming agents, etc. due to its excellent environmental protection properties (ODP is 0, and GWP is only 4), and fluoroolefins such as trifluorochloropropene and trifluoropropene are key intermediates and raw materials for synthesizing HFO-1234yf, so that there is a high industrial demand for them.
[0003] However, the synthesis process of various fluorocarbons is always restricted by many technical bottlenecks. For example, the catalyst used to prepare these fluorocarbons is the biggest technical problem to be overcome, and all the catalysts reported in the prior art have the following problems: poor catalyst life, which leads to frequent catalyst replacement and regeneration during the fluorination reaction, resulting in a significant decrease in process production efficiency and a straight-line increase in process cost. In order to prolong the life of the catalyst, relevant researchers have taken many technical means, such as improving the composition of the catalyst, and introducing stabilizers, promoters, and auxiliary agents into the fluorination reaction system, but these means have very limited or even no obvious effect on prolonging the life and stability of the catalyst, and even further increase the process cost and complexity, and also have the risk of significantly reducing the reaction efficiency, product selectivity and yield. Therefore, it is particularly desirable in the art to develop a novel catalyst and process suitable for fluorination reaction to solve the above-mentioned problems which have been long-standing in the prior art.
[0004] In order to solve the above-mentioned problems, the inventors of the present application have successfully developed a brand new catalyst for fluorination reaction, and unexpectedly found that the use of this specially designed catalyst can effectively solve part or all of the problems of the prior art. SUMMARY
[0005] The first aspect of the present application provides a fluorination reaction catalyst, which comprises a carrier and an active metal element, and optionally further comprises an auxiliary metal element.
[0006] the carrier is alumina or alumina modified with a modifying metal element selected from one or more of: La, Ce, Mg, Ca, Zr;
[0007] the active metal element is Cr, Ni or a combination thereof;
[0008] the promoter metal element is selected from one or more of: Fe, Co, Zn, Zr, Cu.
[0009] According to one embodiment of the first aspect of the application, the content of the modifying metal is 0.001-2 wt% based on the weight of the alumina modified with the modifying metal.
[0010] According to another embodiment of the first aspect of the application, the alumina is selected from one or more of: amorphous alumina, alpha-alumina, beta-alumina, gamma-alumina, theta-alumina.
[0011] According to another embodiment of the first aspect of the application, the content of the active metal element is 1-20 wt% based on the weight of the fluorination catalyst.
[0012] According to another embodiment of the first aspect of the application, the active metal element is a combination of Cr and Ni, and the weight ratio of Cr to Ni is 1:1 to 20:1.
[0013] According to another embodiment of the first aspect of the application, the content of the promoter metal element is 0-2 wt% based on the weight of the fluorination catalyst.
[0014] The second aspect of the application provides a method for preparing the fluorination catalyst of the first aspect of the application, the method comprising:
[0015] Step one: providing an active precursor liquid comprising an active metal element and providing a promoter precursor solid or a promoter precursor liquid comprising a promoter metal element;
[0016] Step two: impregnating the carrier with the active precursor liquid; and
[0017] Step three: subjecting the impregnated carrier to a second heat treatment;
[0018] When the carrier is alumina modified with a modifying metal element, the method further comprises, prior to step one, a carrier modification step of impregnating the alumina with a modification precursor liquid comprising a modifying metal element, and then subjecting the impregnated alumina to a first heat treatment;
[0019] The method may also optionally include at least one of the following: in step two, before, during, or after impregnating the carrier with the active precursor liquid, impregnating the carrier with the auxiliary agent precursor liquid; and / or after step three, after the impregnated carrier has undergone a second heat treatment, mixing the carrier with the auxiliary agent precursor solid.
[0020] According to one embodiment of the second aspect of this application, the first heat treatment includes a first drying and a first calcination, wherein the temperature of the first drying is 20-200°C and the temperature of the first calcination is 300-900°C.
[0021] According to another embodiment of the second aspect of this application, the second heat treatment includes a second drying and a second calcination, wherein the temperature of the second drying is 50-200°C and the temperature of the second calcination is 300-900°C.
[0022] According to another embodiment of the second aspect of this application, the active precursor liquid contains nitrates containing active metal elements.
[0023] According to another embodiment of the second aspect of this application, the method further includes: fluorinating the fluorination reaction catalyst after step three.
[0024] The third aspect of this application provides a method for preparing C2-C16 fluorinated olefins or C2-C16 chlorofluoroolefins, the method comprising reacting a C2-C16 chloroalkane or C2-C16 chloroolefin with hydrogen fluoride in the presence of a catalyst; the catalyst being the fluorination reaction catalyst described in the first aspect of this application, or a fluorination reaction catalyst prepared using the method of the second aspect of this application.
[0025] According to one embodiment of the third aspect of this application, the reaction temperature is 250-500°C, and the molar ratio of the hydrogen fluoride to C2-C16 chlorinated alkanes or C2-C16 chlorinated alkenes is 5:1 to 20:1.
[0026] According to another embodiment of the third aspect of this application, the method does not introduce oxygen-containing gas or polymerization inhibitors during the process.
[0027] In the detailed description section below, the method and polymer product of this application will be further described with reference to the accompanying drawings. Attached Figure Description
[0028] Figure 1 A fluorination reaction according to an exemplary embodiment of this application is shown;
[0029] Figure 2The XRD pattern of a catalyst prepared according to an embodiment of this application is shown;
[0030] Figure 3 The image shows a gas chromatogram characterizing the products of a catalytic reaction according to one embodiment of this application. Detailed Implementation
[0031] The “range” disclosed in this document takes the form of a lower limit and an upper limit. It can be one or more lower limits and one or more upper limits, respectively. A given range is defined by selecting a lower limit and an upper limit. The selected lower and upper limits define the boundaries of the particular range. All ranges that can be defined in this way are inclusive and composable; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, it is also expected that ranges of 60-110 and 80-120 are also included. Furthermore, if the minimum range values are listed as 1 and 2, and if the maximum range values are listed as 3, 4, and 5, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5.
[0032] In this application, unless otherwise stated, the numerical range "ab" is a shortened representation of any combination of real numbers from a to b, where a and b are real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" have been listed in this document, and "0-5" is simply a shortened representation of these numerical combinations.
[0033] Unless otherwise specified in this application, all embodiments and preferred embodiments mentioned herein can be combined to form new technical solutions.
[0034] Unless otherwise specified, all technical features and preferred features mentioned herein can be combined to form new technical solutions.
[0035] In this application, unless otherwise specified, the term "comprising" as used herein can be either open-ended or closed-ended. For example, "comprising" may mean that it may also include other components not listed, or it may only include the listed components.
[0036] According to one embodiment of this application, the catalyst of the present invention contains a support and an active metal element. The support may be alumina, or alumina modified by a modified metal element.
[0037] The alumina is selected from: amorphous alumina, α-alumina, β-alumina, γ-alumina, θ-alumina, or a combination of two or more of the above. The alumina can be granular or other irregular shapes, such as spherical, strip, cloverleaf, serrated, Raschig ring, etc., and can be formed by extrusion and pressing.
[0038] According to one embodiment of this application, the particle size of the alumina can be 1-5 mm. According to another embodiment of this application, the specific surface area of the alumina is greater than 100 g / m². 2 Its average pore size is greater than 5 nm, and its particle crushing strength is greater than 50 N / cm.
[0039] The alumina can be commercially available or prepared using methods known in the art. An exemplary method for preparing alumina involves high-temperature calcination of aluminum-containing raw materials or minerals (e.g., boehmite, diaspore, diaspore, and gibbsite), and an alumina carrier having one or more crystalline phases can be obtained by controlling the calcination temperature.
[0040] According to one embodiment of this application, the support in the catalyst is pure alumina, which is not modified with any modified metal elements. In the case where the support is pure alumina, the content of the modified metal elements in the support is 0% by weight.
[0041] According to another embodiment of this application, the support in the catalyst is alumina modified with a modified metal element, comprising both alumina and a modified metal. When the support is alumina modified with a modified metal element, the content of the modified metal element, based on the total weight of the support, is greater than 0.5% by weight and less than 2% by weight, for example, it can be 0.01-1.5% by weight, 0.1-1.2% by weight, or 0.5-1% by weight.
[0042] According to one embodiment of this application, the alumina modified by the modified metal element can be prepared by dissolving a salt or oxide of the modified metal element in water or an aqueous solvent to provide a modification precursor liquid, impregnating the alumina (e.g., one or more alumina as described above) with the modification precursor liquid (hereinafter referred to as "first impregnation"), and then heat-treating the impregnated alumina (hereinafter referred to as "first heat treatment") to obtain the carrier (alumina carrier modified with the modified metal element).
[0043] According to another embodiment of this application, the modified metal element is selected from La, Ce, Mg, Ca, Zr, or a mixture of two or more of the above metal elements. Preferably, the modified metal element is La.
[0044] The modified precursor solution can be an aqueous solution or a solution in an aqueous solvent made using the soluble salt or oxide of the modified metal element described above. For example, the oxide of the modified metal element can be dissolved in water with the assistance of an acid (nitric acid, sulfuric acid, hydrochloric acid, phosphoric acid, etc.) to prepare an aqueous solution.
[0045] According to one embodiment of this application, the concentration of the modified metal element in the modified precursor liquid is 0.01-3 mol / L, for example 0.05-1 mol / L, or 0.1-0.8 mol / L, or 0.2-0.5 mol / L. According to another embodiment of this application, during the first impregnation process, the weight ratio of the modified precursor liquid to the impregnated alumina is 1:50 to 50:1, or 1:20 to 20:1, or 1:10 to 10:1, or 1:5 to 5:1, or 1:2 to 2:1, or 1:1 to 3:2.
[0046] The first impregnation process employs either excessive impregnation or equal-volume impregnation.
[0047] In the over-impregnation process, the volume of the impregnation solution (e.g., modified precursor solution) is typically larger than that of the solid support (e.g., alumina). After the adsorption of the active component (e.g., modified metal element) on the solid support reaches equilibrium, the excess impregnation solution is removed by a solid-liquid separation operation (e.g., filtration), and then the impregnated solid support is subjected to heat treatment (e.g., drying and calcination). In this over-impregnation process, not all the active components contained in the impregnation solution are incorporated into the solid support; rather, a portion of the active components are lost during the solid-liquid separation along with the removed impregnation solution. Therefore, the final amount of active components contained in the solid support is not equal to the amount of active components contained in the impregnation solution.
[0048] In the equal-volume impregnation process, after the adsorption of the active component (e.g., modified metal element) on the solid support reaches equilibrium, the impregnated solid support and the impregnation solution applied thereon are directly subjected to heat treatment (e.g., drying and calcination). In this equal-volume impregnation process, all the active components contained in the impregnation solution are incorporated into the solid support, thus allowing for precise control of the loading of the active component.
[0049] Various equipment can be used for impregnation operations, such as impregnation kettles, impregnation tanks, rotary coating machines, solution atomizers, etc.
[0050] The first heat treatment includes a first drying and a first calcination. The temperature of the first drying is 50-200℃, preferably 110-150℃; the temperature of the first calcination is 300-900℃, preferably 500-700℃.
[0051] The first drying can be carried out using at least one of atmospheric pressure drying, negative pressure vacuum drying, and microwave drying; the first calcination can be carried out using a box furnace, tube furnace, rotary kiln, etc. The atmosphere for the first calcination can be at least one of oxygen, air, and inert atmosphere, preferably an atmosphere containing oxygen.
[0052] The method for preparing the catalyst of the present invention further includes applying an active metal element, which is nickel or chromium, or a mixture of nickel and chromium, onto a support (pure alumina support, or alumina support modified with a modified metal element) by an impregnation method (hereinafter referred to as "second impregnation"). In the case of using a mixture of nickel and chromium, the weight ratio of nickel to chromium is 1:1 to 1:20, for example 1:1 to 1:15, or 1:1 to 1:10, or 1:1 to 1:5, or 1:1 to 1:2.
[0053] Based on the total weight of the catalyst of the present invention, the content of the active metal element is 1-20% by weight, for example 1-15% by weight, or 1-10% by weight, or 1-5% by weight, or 1-3% by weight.
[0054] The impregnation solution (active precursor solution) used in the second impregnation can be an aqueous solution or a solution in an aqueous solvent made from the soluble salt or oxide of the aforementioned active metal element. The soluble salt of the active metal element can be selected from one or more of the following: nitrates, sulfates, chlorides (i.e., hydrochlorides), phosphates, hydrogen phosphates, dihydrogen phosphates, formates, acetates, methanesulfonates, etc., preferably nitrates. Alternatively, the oxide of the aforementioned active metal element can be dissolved in water with the assistance of an acid (nitric acid, sulfuric acid, hydrochloric acid, phosphoric acid, etc.) to prepare the active precursor solution. A small amount of acid can be added to the active precursor solution to adjust the pH value and inhibit hydrolysis.
[0055] According to one embodiment of this application, based on the weight of the active precursor liquid, the total concentration of active metal elements in the active precursor liquid is 0.1-10% by weight, for example, 0.5-8% by weight, or 0.8-6% by weight, or 1-5% by weight. According to another embodiment of this application, in the second impregnation process, the weight ratio of the active precursor liquid to the impregnated carrier is 1:20 to 100:1, or 1:10 to 50:1, or 1:1 to 20:1, or 2:5 to 10:1, or 3:1 to 6:1.
[0056] The second impregnation process employs either excessive impregnation or equal-volume impregnation, preferably equal-volume impregnation.
[0057] The second impregnation operation can be performed using various equipment, such as impregnation kettles, impregnation tanks, rotary coating machines, solution atomizers, etc.
[0058] The second heat treatment includes a second drying and a second calcination. The temperature of the second drying is 50-200℃, preferably 110-150℃. The temperature of the first calcination is 300-900℃, preferably 350-650℃.
[0059] The second drying can be carried out using at least one of atmospheric pressure drying, negative pressure vacuum drying, and microwave drying; the second calcination can be carried out using a box furnace, tube furnace, rotary kiln, etc. The atmosphere for the second calcination can be at least one of oxygen, air, and inert atmosphere, preferably an atmosphere containing oxygen.
[0060] According to one embodiment of this application, the catalyst of the present invention does not contain auxiliary metal elements.
[0061] According to another embodiment of this application, the catalyst of the present invention may also contain an auxiliary metal element in addition to the support and the active metal element. The auxiliary metal element is selected from one or more of the following: Fe, Co, Zn, Zr, and Cu.
[0062] According to another embodiment of this application, when the catalyst contains an auxiliary metal element, the content of the auxiliary metal element is 0.001-2% by weight, for example, 0.1-1.8% by weight, or 0.5-1.5% by weight, or 0.6-1.2% by weight, or 0.8-1.0% by weight, based on the weight of the catalyst.
[0063] When the catalyst contains an auxiliary metal element, the auxiliary metal element can be incorporated into the catalyst through any one or both of the following methods:
[0064] The first method is to impregnate the carrier with an additive precursor liquid (hereinafter referred to as "third impregnation") before, during, or after the second impregnation, so as to incorporate the additive metal into the catalyst.
[0065] The second method involves mixing the additive precursor solid containing the additive metal element with the carrier solid after the second impregnation and the second heat treatment.
[0066] In the first method, the auxiliary agent precursor solution used in the third impregnation can be an aqueous solution or a solution in an aqueous solvent made using a soluble salt or oxide of the aforementioned auxiliary metal element. The soluble salt of the auxiliary metal element can be selected from one or more of the following: nitrates, sulfates, chlorides (i.e., hydrochlorides), phosphates, hydrogen phosphates, dihydrogen phosphates, formates, acetates, methanesulfonates, etc. Alternatively, the oxides of the aforementioned auxiliary metal elements can be dissolved in water with the assistance of acids (nitric acid, sulfuric acid, hydrochloric acid, phosphoric acid, etc.) to prepare an active precursor solution. A small amount of acid can be added to the auxiliary agent precursor solution to adjust the pH value and inhibit hydrolysis.
[0067] According to one embodiment of this application, based on the weight of the additive precursor liquid, the total concentration of active metal elements in the additive precursor liquid is 0.1-10% by weight, for example, 0.5-8% by weight, or 0.8-6% by weight, or 1-5% by weight. According to another embodiment of this application, in the third impregnation process, the weight ratio of the additive precursor liquid to the impregnated carrier is 1:20 to 100:1, or 1:10 to 50:1, or 1:1 to 20:1, or 2:5 to 10:1, or 3:1 to 6:1.
[0068] The third impregnation process employs either excessive impregnation or equal-volume impregnation, preferably equal-volume impregnation.
[0069] The third impregnation operation can be performed using various equipment, such as impregnation kettles, impregnation tanks, rotary coating machines, solution atomizers, etc.
[0070] According to a preferred embodiment of this application, the third impregnation and the second impregnation are combined into one step. In this case, the active precursor liquid used in the second impregnation and the auxiliary precursor liquid used in the second impregnation are combined into the same impregnation liquid, which simultaneously contains active metal elements and auxiliary metal elements, and the concentrations and ratios of the active metal elements and auxiliary metal elements are as described above. In this case, when the impregnation steps are combined into one step, the second heat treatment described above can be performed.
[0071] According to another embodiment of this application, the third impregnation is performed before or after the second impregnation. A third heat treatment (which includes a third drying and a third calcination, with the same temperature, atmosphere, and equipment as the second heat treatment described above) can be performed between the second and third impregnations. Alternatively, no heat treatment may be performed; instead, the second heat treatment can be performed uniformly after both the second and third impregnations have been performed.
[0072] In the second method, after the second impregnation and the second heat treatment, an additive precursor solid containing an additive metal element (e.g., an oxide of an additive metal) is mixed with a support solid to incorporate the additive precursor element into the catalyst.
[0073] According to an exemplary embodiment of this application, in the catalyst of the present invention, the support is unmodified alumina, and the catalyst contains an active metal element and a support, but does not contain an auxiliary metal element.
[0074] According to an exemplary embodiment of this application, in the catalyst of the present invention, the support is modified alumina, and the catalyst contains an active metal element and a support, but does not contain an auxiliary metal element.
[0075] According to an exemplary embodiment of this application, in the catalyst of the present invention, the support is unmodified alumina, and the catalyst contains an active metal element, a support, and an auxiliary metal element.
[0076] According to a preferred exemplary embodiment of this application, nitrates are used to prepare an active precursor solution.
[0077] After the above steps, the catalyst needs to undergo fluorination treatment before it can be used in the catalytic reaction method of the present invention. The catalyst fluorination treatment typically involves treating the catalyst with a fluorinating agent (e.g., HF, F2 gas, etc.) or a mixture of a fluorinating agent and an inert gas (e.g., nitrogen, argon, etc.). The pressure of the catalyst fluorination treatment can be from 0.01 kPa to 15 bar, for example, 0.05 kPa-10 bar, or 0.1 kPa-5 bar; the temperature can be 200-500 °C, for example, 250-450 °C, or 300-400 °C, or 320-390 °C.
[0078] As can be seen, after the catalyst is fluorinated, all the metal elements in the catalyst, such as aluminum, modified metal elements, active metal elements, and auxiliary metal elements in the support, are at least partially or completely fluorinated (in the form of fluorides). Some of the above-mentioned metal elements may also be in the form of chlorides, oxides, chlorides, or other types of salts.
[0079] According to one embodiment of this application, the "fluorination reaction catalyst" of the present invention refers to a catalyst for carrying out a fluorination reaction, wherein the fluorination reaction refers to the reaction of C2-C16 chlorinated alkanes or C2-C16 chlorinated olefins with hydrogen fluoride in the presence of the catalyst to generate C2-C16 fluorinated olefins or C2-C16 fluorochlorinated olefins.
[0080] According to an exemplary embodiment of this application, the C2-C16 chlorinated alkane or C2-C16 chlorinated olefin used as a reactant in the reaction can be a C2-C14 chlorinated alkane or C2-C14 chlorinated olefin, or a C2-C12 chlorinated alkane or C2-C12 chlorinated olefin, or a C2-C8 chlorinated alkane or C2-C8 chlorinated olefin, or a C2-C6 chlorinated alkane or C2-C6 chlorinated olefin, or a C2-C4 chlorinated alkane or C2-C4 chlorinated olefin. In the chlorinated alkane or chlorinated olefin, some or all of the hydrogen atoms (CH) directly bonded to carbon atoms in the molecule are replaced by chlorine atoms, for example, the substitution ratio of chlorine atoms (number of substituted chlorine atoms / total number of hydrogen atoms before substitution × 100%) is 20-100%, or 40-100%, or 50-100%, or 60-100%, or 70-100%. In addition, each molecule of the chlorinated olefin contains 1-4 carbon-carbon double bonds, preferably 1-3 carbon-carbon double bonds, and more preferably 1-2 carbon-carbon double bonds.
[0081] The target product, a C2-C16 fluorinated olefin or a C2-C16 chlorofluoroolefin, obtained by the reaction of this invention has the same number of carbon atoms as the chlorinated alkane or chlorinated olefin used as a raw material. In the fluorinated olefin, some or all of the hydrogen atoms (CH) directly bonded to carbon atoms in the molecule are replaced by fluorine atoms, for example, the substitution ratio of fluorine atoms (number of substituted fluorine atoms / total number of hydrogen atoms before substitution × 100%) is 30-100%, or 40-100%, or 50-100%, or 60-100%. In the fluorochloroolefin, some or all of the hydrogen atoms (CH) directly bonded to carbon atoms in the molecule are replaced by fluorine or chlorine atoms. For example, the total substitution ratio of fluorine and chlorine atoms [(number of substituted fluorine atoms + number of chlorine atoms) / total number of hydrogen atoms before substitution × 100%) is 30-100%, or 40-100%, or 50-100%, or 60-100%, and the molar ratio of fluorine atoms to chlorine atoms in the fluorochloroolefin is 12:1 to 1:1, for example 6:1 to 1:1, or 3:1 to 1:1. In addition, each molecule of the fluorinated olefin or fluorochloroolefin contains 1-4 carbon-carbon double bonds, preferably 1-3 carbon-carbon double bonds, and more preferably 1-2 carbon-carbon double bonds.
[0082] According to a specific implementation method, such as Figure 1 As shown, the raw material in the reaction of the present invention is pentachloropropane, more specifically 1,1,1,2,3-pentachloropropane (HCC-240db), which reacts with hydrogen fluoride in a reaction system containing the catalyst of the present invention to generate the target product trifluorochloropropene, more specifically 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf).
[0083] According to one embodiment of this application, in Figure 1 In the illustrated embodiment, not only is the target product trifluorochloropropylene generated, but also the high-value byproduct trifluoropropylene (HFO-1243zf) is generated.
[0084] According to another embodiment of this application, the catalytic reaction method of the present invention only requires the introduction of the C2-C16 chlorinated alkane or C2-C16 chlorinated olefin feedstock to be fluorinated and hydrogen fluoride into the reactor, without the need to introduce oxygen-containing gas and polymerization inhibitors into the reactor. The oxygen-containing gas includes oxygen, air, ozone, etc. Conventional examples of polymerization inhibitors include one or more of the following: p-methoxybenzopane, tert-amylbenzopane, limonene, d,1-limonene, hydroquinone, quinone, epoxides, and amines.
[0085] The progress achieved by this invention lies in:
[0086] 1. The catalyst of the present invention has high activity and can achieve excellent feed conversion and target product selectivity without the need for oxygen-containing gas and polymerization inhibitor feed.
[0087] 2. When the catalyst of this invention is used to catalyze fluorination reactions, the byproducts produced are also high-value byproducts;
[0088] 3. The catalyst of the present invention has high strength, which can effectively solve the problems of easy chemical deactivation and physical cracking of existing catalysts, and has a long catalytic life;
[0089] 4. The catalyst of the present invention has excellent regeneration performance, can be easily regenerated, and the regenerated catalyst can restore its original catalytic activity.
[0090] The following embodiments illustrate the methods of this application in detail, with the aim of providing a better understanding of the content of this application. It should be understood that these embodiments are merely illustrative and not restrictive. Unless otherwise stated, the reagents used in the embodiments are commercially available. Unless otherwise specified, the methods and conditions used in the embodiments are conventional methods and conditions.
[0091] Example
[0092] The alumina used in the following examples was obtained by heating boehmite purchased from Jiangxi Tuoci New Materials Co., Ltd. in a muffle furnace at 550°C for 12 hours in an air atmosphere. The resulting powder was characterized by XRD to confirm that it was γ-alumina crystal form, and its specific surface area was determined to be 214 m² using nitrogen adsorption-desorption technology. 2 / g, is compressed into strip-shaped granules with a diameter of 4-6 mm using extrusion tableting technology;
[0093] The HCC-240db used in the examples was purchased from Xi'an Shiye Chemical Products Co., Ltd. The water used was deionized water, and all other reagents used were analytical grade and were used directly without further treatment.
[0094] Example 1
[0095] In this embodiment, a catalyst containing Cr and Ni elements supported on an alumina support was prepared, and a catalytic fluorination reaction was carried out using the catalyst.
[0096] 1.6 g of nickel chloride and 1.6 g of chromium chloride were dissolved in 100 mL of water. A small amount of 1 M nitric acid was added to adjust the pH of the solution to 2, forming a clear and transparent Cr-Ni impregnation solution. This impregnation solution was thoroughly mixed with 20 g of alumina support in a beaker at room temperature and allowed to impregnate for 2 hours under static conditions. The beaker was then transferred to an oven and dried along with the solution at 130 °C for 12 hours. The dried material was then transferred to a crucible and calcined in a muffle furnace at 500 °C for 3 hours under air conditions. The specific surface area of the calcined catalyst was measured to be 182 m² using BET. 2 / g, with an average pore size of 15.6nm.
[0097] The calcined catalyst was completely loaded into a fixed-bed reactor made of nickel alloy. First, nitrogen gas was introduced to dry the reactor at 300°C for 2 hours. Then, the atmosphere was changed to hydrogen fluoride gas, which was introduced into the reactor at a flow rate of 30 ml / min. The pressure inside the reactor was 0.5 kPa, and the temperature was increased to 350°C at a rate of 1°C / min and maintained for approximately 3 hours. The fluorination treatment of the catalyst was completed after the temperature rise within the reactor ceased to be significant. The specific surface area of the fluorinated catalyst was measured to be 28 m² using BET. 2 / g, with an average pore size of 0.45nm.
[0098] Then, the HCC-240db feedstock and hydrogen fluoride were simultaneously introduced into the reactor, and a metering pump was used to deliver the HCC-240db feedstock at a liquid hourly space velocity of 0.6 g·(gcat·h). -1 The molar ratio of hydrogen fluoride to HCC-240db was 10:1, the reaction temperature was 300℃, and the reaction pressure was 0.1 kPa. The reaction product stream output from the reactor was washed with water and alkali and dried. A gaseous sample was then taken and analyzed by gas chromatography.
[0099] The reaction continues until the feed conversion rate drops to 90% of the initial conversion rate. At this point, the input of HCC-240db and hydrogen fluoride is temporarily stopped, and a mixture of oxygen and nitrogen (oxygen concentration controlled at approximately 20%) is introduced into the reactor. The reactor is then heated at 450°C for 3 hours to regenerate the catalyst. The gas in the reactor is then replaced with hydrogen fluoride, and the HCC-240db feed and hydrogen fluoride are reintroduced under the same conditions to restart the catalytic reaction. The catalyst regeneration time is not included in the total catalytic reaction time.
[0100] After 720 hours of continuous reaction, the composition of the gas phase sample was measured to be HCC-240db~0.0%, HCFO-1233xf~97.2%, HFO-1243zf~2.0%, HCFO-1223~0.5%, and others~0.3%.
[0101] After 1600 hours of continuous reaction, the composition of the gas phase sample was measured to be HCC-240db~0.0%, HCFO-1233xf~96.5%, HFO-1243zf~2.8%, HCFO-1223~0.4%, and others~0.3%.
[0102] The reaction was continued for 3100 hours (during which the catalyst was regenerated 5 times in total). The composition of the gas phase sample was measured to be HCC-240db~0.0%, HCFO-1233xf~94.5%, HFO-1243zf~3.1%, HCFO-1223~0.8%, and others~0.6%.
[0103] Example 2:
[0104] In this embodiment, a catalyst containing Cr and Ni elements supported on a lanthanum-modified alumina support was prepared, and a catalytic fluorination reaction was carried out using the catalyst.
[0105] First, 0.02 g of lanthanum oxide and 5 ml of 1M nitric acid were dissolved in 50 ml of water to form a clear and transparent solution. This solution was then thoroughly mixed with 20 g of alumina support in a beaker at room temperature and allowed to steep for 2 hours under static conditions. The beaker was then transferred to an oven and dried along with the solution at 100°C for 12 hours. The dried material was then transferred to a crucible and calcined in a muffle furnace at 600°C for 6 hours under air conditions. This yielded the lanthanum-modified alumina support.
[0106] 1.6 g of nickel chloride and 1.6 g of chromium chloride were dissolved in 100 mL of water. A small amount of 1 M nitric acid was added to adjust the pH of the solution to 2, forming a clear and transparent Cr-Ni impregnation solution. This impregnation solution was thoroughly mixed with 20 g of the aforementioned lanthanum-modified alumina support in a beaker at room temperature. The mixture was allowed to stand for 2 hours, after which the beaker was transferred to an oven and dried along with the solution at 130 °C for 12 hours. The dried material was then transferred to a crucible and calcined in a muffle furnace at 500 °C for 3 hours under air conditions. The specific surface area of the calcined catalyst was measured to be 126 m². 2 / g, with an average pore size of 0.96nm. Figure 2 The XRD spectrum of the prepared catalyst is shown, indicating that the alumina support in the catalyst remains in the γ-alumina crystal form.
[0107] The calcined catalyst was completely loaded into a fixed-bed reactor made of nickel alloy. First, nitrogen gas was introduced to dry the reactor at 300°C for 2 hours. Then, the atmosphere was replaced with hydrogen fluoride gas, which was introduced into the reactor at a flow rate of 30 ml / min. The pressure inside the reactor was 0.1 kPa, and the temperature was increased to 350°C at a rate of 1°C / min and maintained for approximately 3 hours. The fluorination treatment of the catalyst was complete after the temperature rise within the reactor ceased to be significant. The specific surface area of the fluorinated catalyst was measured to be 28.4 m² using BET analysis. 2 / g, with an average pore size of 0.62 nm.
[0108] Then, the HCC-240db feedstock and hydrogen fluoride were simultaneously introduced into the reactor, and a metering pump was used to deliver the HCC-240db feedstock at a liquid hourly space velocity of 0.6 g·(gcat·h). -1 The molar ratio of hydrogen fluoride to HCC-240db was 10:1, the reaction temperature was 300℃, and the reaction pressure was 0.1 kPa. The reaction product stream output from the reactor was washed with water and alkali and dried. A gaseous sample was then taken and analyzed by gas chromatography. Figure 3 The gas chromatogram of the reaction product sample is shown.
[0109] The reaction continues until the feed conversion rate drops to 90% of the initial conversion rate. At this point, the input of HCC-240db and hydrogen fluoride is temporarily stopped, and a mixture of oxygen and nitrogen (oxygen concentration controlled at approximately 20%) is introduced into the reactor. The reactor is then heated at 450°C for 4 hours to regenerate the catalyst. The gas in the reactor is then replaced with hydrogen fluoride, and the HCC-240db feed and hydrogen fluoride are reintroduced under the same conditions to restart the catalytic reaction. The catalyst regeneration time is not included in the total catalytic reaction time.
[0110] After 720 hours of continuous reaction, the composition of the gas phase sample was measured to be HCC-240db~0.0%, HCFO-1233xf~97.2%, HFO-1243zf~2.0%, HCFO-1223~0.5%, and others~0.3%.
[0111] Example 3:
[0112] In this embodiment, the steps and process conditions of Example 1 are completely repeated, except that nickel chloride and chromium chloride in Example 1 are replaced with nickel nitrate and chromium nitrate, while ensuring that the loading mass percentage remains unchanged.
[0113] After 720 hours of continuous reaction, the composition of the gas phase sample was measured to be HCC-240db~0.0%, HCFO-1233xf~98.9%, HFO-1243zf~0.3%, HCFO-1223~0.2%, and others~0.6%.
[0114] Example 4:
[0115] In this embodiment, a catalyst containing Cr, Ni, and copper elements supported on an unmodified alumina support was prepared, and a catalytic fluorination reaction was carried out using the catalyst.
[0116] 1.6 g of nickel chloride and 1.6 g of chromium chloride were dissolved in 100 mL of water. A small amount of 1 M nitric acid was added to adjust the pH of the solution to 2, forming a clear and transparent Cr-Ni impregnation solution. This impregnation solution was thoroughly mixed with 20 g of alumina support in a beaker at room temperature and allowed to impregnate for 2 hours under static conditions. The beaker was then transferred to an oven and dried along with the solution at 130 °C for 12 hours. The dried material was then transferred to a crucible and calcined in a muffle furnace at 500 °C for 3 hours under air conditions. The specific surface area of the calcined catalyst was measured to be 134 m². 2 / g, with an average pore size of 0.92nm.
[0117] The calcined catalyst was mixed with 0.4 g of cuprous oxide powder in a coating machine for 30 minutes. The resulting solid catalyst was then loaded into a fixed-bed reactor made of nickel alloy. First, nitrogen gas was introduced to dry the catalyst at 300°C for 2 hours. Then, the atmosphere was changed to hydrogen fluoride gas, which was introduced into the reactor at a flow rate of 30 ml / min. The pressure inside the reactor was 0.1 kPa, and the temperature was increased to 350°C at a rate of 1°C / min and maintained for approximately 3 hours. The fluorination treatment of the catalyst was completed after the temperature rise within the reactor ceased to be significant. The specific surface area of the fluorinated catalyst was measured to be 25.7 m² using BET analysis. 2 / g, with an average pore size of 0.60 nm.
[0118] Then, the HCC-240db feedstock and hydrogen fluoride were simultaneously introduced into the reactor, and a metering pump was used to deliver the HCC-240db feedstock at a liquid hourly space velocity of 0.6 g·(gcat·h). -1 The molar ratio of hydrogen fluoride to HCC-240db was 10:1, the reaction temperature was 300℃, and the reaction pressure was 0.1 kPa. The reaction product stream output from the reactor was washed with water and alkali and dried. A gaseous sample was then taken and analyzed by gas chromatography.
[0119] The reaction continues until the feed conversion rate drops to 90% of the initial conversion rate. At this point, the input of HCC-240db and hydrogen fluoride is temporarily stopped, and a mixture of oxygen and nitrogen (oxygen concentration controlled at approximately 20%) is introduced into the reactor. The reactor is then heated at 450°C for 4 hours to regenerate the catalyst. The gas in the reactor is then replaced with hydrogen fluoride, and the HCC-240db feed and hydrogen fluoride are reintroduced under the same conditions to restart the catalytic reaction. The catalyst regeneration time is not included in the total catalytic reaction time.
[0120] After 720 hours of continuous reaction, the composition of the gas phase sample was measured to be HCC-240db~0.0%, HCFO-1233xf~96.9%, HFO-1243zf~0.6%, HCFO-1223~1.3%, and others~1.2%.
[0121] Example 5:
[0122] In this embodiment, a catalyst containing Cr, Ni and iron elements supported on an unmodified alumina support was prepared, and a catalytic fluorination reaction was carried out using the catalyst.
[0123] 1.6 g of nickel chloride, 1.6 g of chromium chloride, and 0.8 g of ferric chloride were dissolved in 100 mL of water. A small amount of 1 M nitric acid was added to adjust the pH of the solution to 2, forming a clear and transparent Cr-Ni-Fe impregnation solution. This impregnation solution was thoroughly mixed with 20 g of alumina support in a beaker at room temperature and allowed to impregnate for 2 hours under static conditions. The beaker was then transferred to an oven and dried along with the solution at 130 °C for 12 hours. The dried material was then transferred to a crucible and calcined in a muffle furnace at 500 °C for 3 hours under air conditions. The specific surface area of the calcined catalyst was measured to be 31.4 m². 2 / g, with an average pore size of 0.92nm.
[0124] The calcined catalyst was completely loaded into a fixed-bed reactor made of nickel alloy. First, nitrogen gas was introduced to dry the reactor at 300°C for 2 hours. Then, the atmosphere was replaced with hydrogen fluoride gas, which was introduced into the reactor at a flow rate of 30 ml / min. The pressure inside the reactor was 0.1 kPa, and the temperature was increased to 350°C at a rate of 1°C / min and maintained for approximately 3 hours. The fluorination treatment of the catalyst was complete after the temperature rise within the reactor ceased to be significant. The specific surface area of the fluorinated catalyst was measured to be 27.9 m² using BET analysis. 2 / g, with an average pore size of 0.65 nm.
[0125] Then, the HCC-240db feedstock and hydrogen fluoride were simultaneously introduced into the reactor, and a metering pump was used to deliver the HCC-240db feedstock at a liquid hourly space velocity of 0.6 g·(gcat·h). -1 The molar ratio of hydrogen fluoride to HCC-240db was 10:1, the reaction temperature was 300℃, and the reaction pressure was 0.1 kPa. The reaction product stream output from the reactor was washed with water and alkali and dried. A gaseous sample was then taken and analyzed by gas chromatography.
[0126] The reaction continues until the feed conversion rate drops to 90% of the initial conversion rate. At this point, the input of HCC-240db and hydrogen fluoride is temporarily stopped, and a mixture of oxygen and nitrogen (oxygen concentration controlled at approximately 20%) is introduced into the reactor. The reactor is then heated at 450°C for 4 hours to regenerate the catalyst. The gas in the reactor is then replaced with hydrogen fluoride, and the HCC-240db feed and hydrogen fluoride are reintroduced under the same conditions to restart the catalytic reaction. The catalyst regeneration time is not included in the total catalytic reaction time.
[0127] After 720 hours of continuous reaction, the composition of the gas phase sample was measured to be HCC-240db~0.0%, HCFO-1233xf~96.6%, HFO-1243zf~0.6%, HCFO-1223~2.6%, and others~0.2%.
[0128] Example 6:
[0129] In this embodiment, a catalyst containing Cr, Ni, and zirconium elements supported on an unmodified alumina support was prepared, and a catalytic fluorination reaction was carried out using the catalyst.
[0130] Dissolve 1.6 g of nickel chloride and 1.6 g of chromium chloride in 100 mL of water, add a small amount of 1 M nitric acid to adjust the pH of the solution to 2, forming a clear and transparent Cr-Ni impregnation solution. In a beaker at room temperature, thoroughly mix the impregnation solution with 20 g of alumina carrier and continue impregnation for 2 hours under static conditions. Then transfer the beaker to an oven and dry it together with the solution at 130 °C for 12 hours. Then transfer the dried material to a crucible and calcine it in a muffle furnace at 500 °C for 3 hours under air conditions.
[0131] In a coating machine, the calcined catalyst and 0.4 g of zirconium oxide powder were mixed for 30 minutes. The resulting solid catalyst was then loaded into a fixed-bed reactor made of nickel alloy. First, nitrogen gas was introduced into the reactor at 300°C for 2 hours to dry it. Then, the atmosphere was changed to hydrogen fluoride gas, which was introduced into the reactor at a flow rate of 30 ml / min. The pressure inside the reactor was 0.1 kPa, and the temperature of the reactor was increased to 350°C at a heating rate of 1°C / min and maintained for about 3 hours. After the temperature inside the reactor no longer rose significantly, the fluorination treatment of the catalyst was completed.
[0132] Then, the HCC-240db feedstock and hydrogen fluoride were simultaneously introduced into the reactor, and a metering pump was used to deliver the HCC-240db feedstock at a liquid hourly space velocity of 0.6 g·(gcat·h). -1 The molar ratio of hydrogen fluoride to HCC-240db was 10:1, the reaction temperature was 300℃, and the reaction pressure was 0.1 kPa. The reaction product stream output from the reactor was washed with water and alkali and dried. A gaseous sample was then taken and analyzed by gas chromatography.
[0133] The reaction continues until the feed conversion rate drops to 90% of the initial conversion rate. At this point, the input of HCC-240db and hydrogen fluoride is temporarily stopped, and a mixture of oxygen and nitrogen (oxygen concentration controlled at approximately 20%) is introduced into the reactor. The reactor is then heated at 450°C for 4 hours to regenerate the catalyst. The gas in the reactor is then replaced with hydrogen fluoride, and the HCC-240db feed and hydrogen fluoride are reintroduced under the same conditions to restart the catalytic reaction. The catalyst regeneration time is not included in the total catalytic reaction time.
[0134] After 720 hours of continuous reaction, the composition of the gas phase sample was measured to be HCC-240db~0.0%, HCFO-1233xf~97.6%, HFO-1243zf~0.5%, HCFO-1223~1.2%, and others~0.7%.
Claims
1. A fluorination reaction catalyst comprising a support and an active metal element, and optionally further comprising an auxiliary metal element; the support is alumina or alumina modified with a modifying metal element selected from one or more of: La, Ce, Mg, Ca, Zr; the active metal element is Cr, Ni or a combination thereof; the auxiliary metal element is selected from one or more of: Fe, Co, Zn, Zr, Cu.
2. The fluorination reaction catalyst according to claim 1, characterized by, the content of the modifying metal is 0.001-2 wt% based on the weight of the alumina modified with the modifying metal; the alumina is selected from one or more of: amorphous alumina, a-alumina, β-alumina, γ-alumina, θ-alumina.
3. The fluorination reaction catalyst according to claim 1, characterized by, the content of the active metal element is 1-20 wt% based on the weight of the fluorination reaction catalyst.
4. The fluorination reaction catalyst according to claim 3, characterized by the active metal element is a combination of Cr and Ni, and the weight ratio of Cr to Ni is 1:1 to 20:
1.
5. The fluorination reaction catalyst according to claim 1, wherein the content of the auxiliary metal element is 0-2 wt% based on the weight of the fluorination reaction catalyst.
6. A method of preparing the fluorination reaction catalyst of any one of claims 1-5, the method comprising: Step one: providing an active precursor liquid comprising an active metal element and providing an auxiliary precursor solid or an auxiliary precursor liquid comprising an auxiliary metal element; Step two: impregnating the support with the active precursor liquid; and Step three: subjecting the impregnated support to a second heat treatment; when the support is alumina modified with a modifying metal element, the method further comprises, prior to Step one, a support modification step of impregnating alumina with a modifying precursor liquid comprising a modifying metal element and then subjecting the impregnated alumina to a first heat treatment; the method further optionally comprises at least one of: in Step two, impregnating the support with an auxiliary precursor liquid before, during or after impregnating the support with the active precursor liquid; and / or after Step three, mixing the support with an auxiliary precursor solid after the impregnated support has been subjected to the second heat treatment.
7. The method of claim 6, wherein, the first heat treatment comprises a first drying at a temperature of 20-200°C and a first calcination at a temperature of 300-900°C; and the second heat treatment comprises a second drying at a temperature of 50-200°C and a second calcination at a temperature of 300-900°C; the method further comprises fluorination of the fluorination reaction catalyst after Step three.
8. The method of claim 6, wherein, the active precursor liquid contains a nitrate salt comprising the active metal element.
9. A method of preparing a C2-C16 fluorinated alkene or a C2-C16 fluorochlorinated alkene, the method comprising reacting a C2-C16 chlorinated alkane or a C2-C16 chlorinated alkene with hydrogen fluoride in the presence of a catalyst; the catalyst being a fluorination reaction catalyst according to any one of claims 1-5 or being a fluorination reaction catalyst prepared using a method according to any one of claims 6-8.
10. The method of claim 9, wherein, The reaction temperature is 250-500°C and the molar ratio of hydrogen fluoride to C2-C16 chlorinated alkane or C2-C16 chlorinated alkene is 5:1 to 20:
1. The method does not input oxygen-containing gas or polymerization inhibitor during the process.