Fluorine-containing organic matter treatment method, hydrogen chloride purification method, chlorine gas preparation method and metal fluoride preparation method

Abstract

The invention relates to the field of fluorine-containing organic matter treatment, in particular to a fluorine-containing organic matter treatment method, a fluorine-containing organic matter-containing hydrogen chloride purification method, a chlorine preparation method and a metal fluoride preparation method. The treatment method of the fluorine-containing organic matter comprises the steps that in the presence of hydrogen chloride, the fluorine-containing organic matter makes contact with a metal compound, metal fluoride is generated, and L acid exists in the metal compound under the action of hydrogen chloride. Therefore, the fluorine-containing organic matters in the hydrogen chloride can be effectively removed, so that the hydrogen chloride is purified and is further used for preparing chlorine, and meanwhile, the fluorine-containing organic matters in the hydrogen chloride can also be converted into metal fluorides with high additional value, such as aluminum fluoride.

Description

Technical Field

[0001] This invention relates to the field of fluorinated organic compound treatment, specifically to a method for treating fluorinated organic compounds, a method for purifying hydrogen chloride containing fluorinated organic compounds, a method for preparing chlorine gas, and a method for preparing metal fluorides. Background Technology

[0002] As an important branch of the fluorochemical industry, organofluorine chemicals mainly involve a variety of fluorinated organic compounds such as fluoropolymers, fluorinated fine chemicals, and fluorocarbons. They are widely used in fields such as electrical appliances, pharmaceuticals, chips, transportation, new energy, and environmental protection. In recent years, the market size of the organofluorine chemical industry has continued to grow.

[0003] In the production process of organofluorine chemicals, organic compounds are typically first chlorinated with chlorine gas to generate organochlorides, and then hydrogen fluoride is reacted with the organochlorides to obtain the corresponding fluorinated organic compounds. During this process, a large amount of hydrogen chloride is generated as a byproduct, and the resulting hydrogen chloride often contains small amounts of fluorinated organic compounds and hydrogen fluoride. Depending on the fluorine chemical process, the types of fluorinated organic compounds may include, for example, CHF3, CHClF2, CHF2CF3, CH3CF3, CH2FCF3, CF3CF2Cl, etc. The production of hydrogen chloride byproducts in this type of organofluorine chemical process is substantial. If it is not properly utilized, it will generate large quantities of hazardous fluorinated hydrochloric acid waste, which is not only difficult to treat effectively but also poses a significant threat to the environment.

[0004] On the other hand, chlorine is an important high-value basic chemical raw material, which is widely used in the production and preparation of PVC (polyvinyl chloride), polyurethane intermediates (MDI, TDI, HDI), organic fluorine, pesticides, pharmaceutical chemicals and other products, and the market demand is expanding year by year.

[0005] If hydrogen chloride, a byproduct of the aforementioned organofluorine chemical industry, can be used to produce chlorine gas, it would not only solve the problem of its disposal, but also enable the recycling of chlorine resources, generating significant economic and social benefits.

[0006] Therefore, the inventors of this invention aimed to use hydrogen chloride, a byproduct of organofluorine chemical industry, for the preparation of chlorine. However, during the experiment, it was found that although the process of preparing chlorine from hydrogen chloride has been industrialized, when using the aforementioned byproduct hydrogen chloride as a raw material to prepare chlorine using existing technologies, the reactivity of the catalyst used for the catalytic oxidation of hydrogen chloride to chlorine rapidly decreases in a short period of time as the byproduct hydrogen chloride containing fluorine-containing organic compounds is introduced. This results in the reaction system being unable to operate stably for a long period, making it difficult to achieve industrial-scale production of chlorine.

[0007] Further research by the inventors revealed that the reason why the above-mentioned production could not proceed smoothly was that the fluorine-containing organic compounds present in hydrogen chloride, a byproduct of organofluorine chemical industry, would poison the catalyst used for the catalytic oxidation of hydrogen chloride to produce chlorine, causing the catalyst to deactivate and thus preventing the successful preparation of chlorine.

[0008] To overcome the aforementioned technical challenges discovered during the research and development process, the inventors of this invention, combining their own experience and professional knowledge, consulted a large amount of existing technical information both domestically and internationally, and made various attempts to eliminate the influence of fluorinated organic compounds on chlorine preparation.

[0009] For example, the inventors attempted to remove fluorinated organic compounds from the byproduct hydrogen chloride using an absorption-desorption process with water. Extensive testing revealed that while this method could reduce the content of fluorinated organic compounds to some extent—for example, from 1-5% to around 0.5%—it could not completely remove them. Furthermore, further testing showed that the low residual fluorinated organic compounds in the desorbed hydrogen chloride still significantly affected the catalyst for the catalytic oxidation of hydrogen chloride to chlorine, making long-term stable chlorine production impossible. In addition, this method is energy-intensive and complex, significantly increasing the production burden and making it unsuitable for industrial production.

[0010] For example, the inventors explored the use of adsorption to selectively adsorb fluorine-containing organic compounds in hydrogen chloride, and conducted adsorption treatment experiments on the byproduct hydrogen chloride containing fluorine-containing organic compounds using resin, activated carbon, molecular sieves, and MOF materials. The results showed that while fluorine-containing organic compounds in the air could be easily adsorbed by adsorbents, those in hydrogen chloride were difficult to selectively adsorb effectively. This may be because the hydrogen chloride content in the byproduct hydrogen chloride gas is often high (over 90%), and hydrogen chloride shares similar properties with some fluorine-containing organic compounds. For example, both hydrogen chloride and trifluoromethane are polar substances, and their boiling points are very similar. Therefore, the presence of hydrogen chloride itself creates intense adsorption competition for the adsorption of fluorine-containing organic compounds, resulting in poor selective adsorption separation and making it impossible to economically and efficiently separate hydrogen chloride and fluorine-containing organic compounds. Furthermore, the closer the properties of fluorine-containing organic compounds are to hydrogen chloride, the more difficult they are to remove through adsorption. For example, while some adsorbents can effectively separate hydrogen chloride and chlorofluoroethane, they cannot separate hydrogen chloride and chlorofluoromethane. On the other hand, among the aforementioned materials, MOF materials exhibit good adsorption performance for fluorinated organic compounds, but their high cost makes large-scale industrial production difficult. Existing adsorption methods and adsorbents are also insufficient for the economical and efficient industrial removal of various fluorinated organic compounds from hydrogen chloride.

[0011] Furthermore, from the perspective of decomposing fluorinated organic compounds specifically, industrial processes have long employed catalytic oxidation and catalytic hydrolysis to convert them. For example, CN117732241A discloses a method for effectively decomposing fluorinated alkanes, which uses catalysts for catalytic oxidation and catalytic hydrolysis of fluorinated waste gas. However, the catalysts used for catalytic oxidation and catalytic hydrolysis are generally solid acid catalysts, such as various metal fluorides. These catalysts have strong surface acidity, are prone to carbon deposition and deactivation, and have poor stability, making it difficult to simultaneously achieve good activity and stability. Sulfates can also be used as such catalysts, but their low acidity results in poor conversion of common raw materials, and they are easily destroyed by the HF produced in the reaction, leading to poor stability. In addition, the high hydrogen chloride content in the aforementioned byproduct hydrogen chloride makes it even more difficult for existing catalytic oxidation and catalytic hydrolysis catalysts to effectively treat fluorinated organic compounds with high hydrogen chloride content.

[0012] Therefore, even though existing technologies have provided a mature industrial route for producing chlorine from conventional hydrogen chloride, the industrial production of chlorine cannot yet be achieved using hydrogen chloride as a byproduct in organofluorine chemicals due to its complexity and unique composition.

[0013] Finding a universally applicable method to remove fluorine-containing organic compounds from by-product hydrogen chloride, and how to use by-product hydrogen chloride from organofluorine chemical industry to achieve the industrial production of chlorine, are technical challenges that urgently need to be solved in this field. Summary of the Invention

[0014] The purpose of this invention is to overcome the difficulty in removing fluorine-containing organic compounds from hydrogen chloride in the prior art, and to provide a method for treating fluorine-containing organic compounds, a method for purifying hydrogen chloride containing fluorine-containing organic compounds, a method for preparing chlorine gas, and a method for preparing metal fluorides.

[0015] The method provided by this invention can not only effectively remove fluorine-containing organic compounds from hydrogen chloride, thus purifying the hydrogen chloride for use in chlorine production, but also convert the fluorine-containing organic compounds in hydrogen chloride into high-value-added metal fluorides such as aluminum fluoride. Therefore, it not only solves the problem of treating hydrogen chloride, a byproduct of organofluorine chemical industry, in the prior art, but also enables the production of chlorine using it as a raw material, and achieves the resource utilization of fluorine-containing organic compounds.

[0016] As mentioned above, the conventional reaction of hydrogen chloride and oxygen to produce chlorine under the action of a catalyst can proceed stably for a long time. However, the inventors of this invention found that when hydrogen chloride containing fluorine-containing organic compounds is used as a raw material, the activity of the catalyst decreases rapidly in a short period of time, and carbon deposits are found on the surface of the catalyst bed where the reaction activity decreases.

[0017] After extensive research and experimentation, it was finally discovered that, unlike other atmospheric conditions, in the presence of hydrogen chloride, specific metal compounds can decompose fluorinated organic compounds and transform themselves into metal fluorides. Furthermore, under sufficient reactant conditions, this reaction can proceed stably and continuously. While the mechanism is not yet fully understood, it is speculated that, with the promotion of hydrogen chloride, specific metal compounds form an adsorbed state with hydrogen chloride, resulting in the presence of Lewis acids. These Lewis acids can initiate the decomposition of fluorinated organic compounds while inhibiting surface carbon deposition, thus allowing the decomposition reaction to be stably maintained until the metal compound is completely fluorinated. This led to the completion of this invention.

[0018] The first aspect of the present invention provides a method for treating fluorinated organic compounds, wherein the method includes:

[0019] In the presence of hydrogen chloride, fluorine-containing organic compounds come into contact with metal compounds to form metal fluorides.

[0020] The metal compound contains L-acid under the action of hydrogen chloride.

[0021] Preferably, the fluorinated organic compound is a fluorinated hydrocarbon with 1-8 carbon atoms, more preferably a fluorinated hydrocarbon with 1-4 carbon atoms, and even more preferably a fluorinated hydrocarbon with 1-2 carbon atoms.

[0022] Preferably, the fluorinated organic compound is represented by the following formula (1) or formula (2):

[0023] C n H x F y Cl z Equation (1);

[0024] C m H o F p Cl q Equation (2);

[0025] In formula (1), n ​​is an integer from 1 to 8, preferably from 1 to 4, and more preferably 1 or 2;

[0026] x and z are both integers greater than or equal to 0, y is an integer greater than or equal to 1, and x + y + z = 2n + 2.

[0027] In equation (2), m is an integer from 2 to 8, preferably from 2 to 4, and more preferably 2;

[0028] o and q are both integers greater than or equal to 0, p is an integer greater than or equal to 1, and o + p + q = 2n.

[0029] Preferably, the fluorinated organic compound is one or more selected from monofluoromethane, difluoromethane, trifluoromethane, difluorochloromethane, difluoroethane, trifluoroethane, tetrafluoroethane, pentafluoroethane, difluorochloroethane, pentafluorochloroethane, difluoroethylene, tetrafluoroethylene, and trifluorochloroethylene; more preferably, the fluorinated organic compound is one or more selected from trifluoromethane, pentafluoroethane, difluoroethylene, and difluorochloromethane.

[0030] Preferably, the metal compound is one or more of metal oxides, hydroxides, chlorides, and chlorides.

[0031] Preferably, the metal in the metal compound is selected from one or more of aluminum, gallium, tin, iron, vanadium, chromium, zirconium, niobium, antimony, zinc, cobalt, nickel, and indium, and is preferably aluminum and / or zirconium.

[0032] Preferably, the metal compound is one or more of aluminum oxide, aluminum hydroxide, hydrated aluminum hydroxide, aluminum chloride, aluminum oxychloride, zirconium oxide, zirconium oxychloride, and zirconium hydroxide; more preferably, the metal compound is one or more of aluminum oxide, aluminum oxychloride, aluminum hydroxide, zirconium oxychloride, and zirconium oxide.

[0033] Preferably, the particle size of the metal compound is 0.001-5 mm; more preferably, the particle size of the metal compound is 0.001-0.2 mm; or even more preferably, the particle size of the metal compound is 0.1-5 mm.

[0034] Preferably, the contact conditions include: a temperature of 50-750°C and a volume hourly space velocity (VHSV) of 1-10000 h⁻¹ for the mixed gas of fluorinated organic compounds and hydrogen chloride. -1 More preferably, the contact conditions include: a temperature of 300-500°C and a volume hourly space velocity (VHSV) of 50-1000 h⁻¹ for the mixed gas of fluorinated organic compounds and hydrogen chloride. -1 .

[0035] Preferably, the contact is carried out under conditions free of water vapor.

[0036] Preferably, the contact is carried out under oxygen-free conditions.

[0037] Preferably, the hydrogen chloride gas containing fluorine-containing organic compounds also contains hydrogen fluoride.

[0038] A second aspect of the present invention provides a method for purifying hydrogen chloride gas containing fluorine-containing organic compounds, wherein the method comprises: contacting the hydrogen chloride gas containing fluorine-containing organic compounds with a metal compound to remove the fluorine-containing organic compounds from the hydrogen chloride gas and generate a metal fluoride, wherein the metal compound contains L acid under the action of hydrogen chloride.

[0039] Preferably, the fluorinated organic compound is a fluorinated hydrocarbon with 1-8 carbon atoms, more preferably a fluorinated hydrocarbon with 1-4 carbon atoms, and even more preferably a fluorinated hydrocarbon with 1-2 carbon atoms.

[0040] Preferably, the fluorinated organic compound is represented by the following formula (1) or formula (2):

[0041] C n H x F y Cl z Equation (1);

[0042] C m H o F p Cl q Equation (2);

[0043] In formula (1), n ​​is an integer from 1 to 8, preferably from 1 to 4, and more preferably 1 or 2;

[0044] x and z are both integers greater than or equal to 0, y is an integer greater than or equal to 1, and x + y + z = 2n + 2.

[0045] In equation (2), m is an integer from 2 to 8, preferably from 2 to 4, and more preferably 2;

[0046] o and q are both integers greater than or equal to 0, p is an integer greater than or equal to 1, and o + p + q = 2n.

[0047] Preferably, the fluorinated organic compound is one or more selected from monofluoromethane, difluoromethane, trifluoromethane, difluorochloromethane, difluoroethane, trifluoroethane, tetrafluoroethane, pentafluoroethane, difluorochloroethane, pentafluorochloroethane, difluoroethylene, tetrafluoroethylene, and trifluorochloroethylene; more preferably, the fluorinated organic compound is one or more selected from trifluoromethane, pentafluoroethane, difluoroethylene, and difluorochloromethane.

[0048] Preferably, the metal compound is one or more of metal oxides, hydroxides, chlorides, and chlorides.

[0049] Preferably, the metal in the metal compound is selected from one or more of aluminum, gallium, tin, iron, vanadium, chromium, zirconium, niobium, antimony, zinc, cobalt, nickel, and indium, and is preferably aluminum and / or zirconium.

[0050] Preferably, the metal compound is one or more of aluminum oxide, aluminum hydroxide, hydrated aluminum hydroxide, aluminum chloride, aluminum oxychloride, zirconium oxide, zirconium oxychloride, and zirconium hydroxide; more preferably, the metal compound is one or more of aluminum oxide, aluminum oxychloride, aluminum hydroxide, zirconium oxychloride, and zirconium oxide.

[0051] Preferably, the particle size of the metal compound is 0.001-5 mm; more preferably, the particle size of the metal compound is 0.001-0.2 mm; or even more preferably, the particle size of the metal compound is 0.1-5 mm.

[0052] Preferably, the contact conditions include: a temperature of 50-750°C and a volume hourly space velocity (VHSV) of 1-10000 h⁻¹ for the mixed gas of fluorinated organic compounds and hydrogen chloride. -1 More preferably, the contact conditions include: a temperature of 300-500°C and a volume hourly space velocity (VHSV) of 50-1000 h⁻¹ for the mixed gas of fluorinated organic compounds and hydrogen chloride. -1 .

[0053] Preferably, the contact is carried out under conditions free of water vapor.

[0054] Preferably, the contact is carried out under oxygen-free conditions.

[0055] Preferably, the hydrogen chloride gas containing fluorine-containing organic compounds also contains hydrogen fluoride.

[0056] Preferably, in the hydrogen chloride gas containing fluorine-containing organic compounds, the content of hydrogen chloride is 90-99.9% by volume, the content of fluorine-containing organic compounds is 0.1-10% by volume, and the content of hydrogen fluoride is 0-1% by volume; more preferably, in the hydrogen chloride gas containing fluorine-containing organic compounds, the content of hydrogen chloride is 95-99.9% by volume, the content of fluorine-containing organic compounds is 0.1-5% by volume, and the content of hydrogen fluoride is 0-1% by volume.

[0057] Preferably, the hydrogen chloride gas containing fluorine-containing organic compounds also contains sulfur hexafluoride and / or sulfur tetrafluoride.

[0058] A third aspect of the present invention provides a method for preparing chlorine gas, wherein chlorine gas is prepared using hydrogen chloride gas containing fluorine-containing organic compounds as a raw material, and the method includes the following steps:

[0059] 1) The raw material is brought into first contact with a metal compound to obtain a defluorination raw material;

[0060] 2) In the presence of a catalyst, the defluorinated feedstock obtained in step 1) is subjected to a second contact with oxygen.

[0061] The metal compound exhibits L-acidity under the action of hydrogen chloride, and the catalyst is a catalyst for the catalytic oxidation of hydrogen chloride to chlorine.

[0062] Preferably, the fluorinated organic compound is a fluorinated hydrocarbon with 1-8 carbon atoms, more preferably a fluorinated hydrocarbon with 1-4 carbon atoms, and even more preferably a fluorinated hydrocarbon with 1-2 carbon atoms.

[0063] Preferably, the fluorinated organic compound is represented by the following formula (1) or formula (2):

[0064] C n H x F y Cl z Equation (1);

[0065] C m H o F p Cl q Equation (2);

[0066] In formula (1), n ​​is an integer from 1 to 8, preferably from 1 to 4, and more preferably 1 or 2;

[0067] x and z are both integers greater than or equal to 0, y is an integer greater than or equal to 1, and x + y + z = 2n + 2.

[0068] In equation (2), m is an integer from 2 to 8, preferably from 2 to 4, and more preferably 2;

[0069] o and q are both integers greater than or equal to 0, p is an integer greater than or equal to 1, and o + p + q = 2n.

[0070] Preferably, the fluorinated organic compound is one or more selected from monofluoromethane, difluoromethane, trifluoromethane, difluorochloromethane, difluoroethane, trifluoroethane, tetrafluoroethane, pentafluoroethane, difluorochloroethane, pentafluorochloroethane, difluoroethylene, tetrafluoroethylene, and trifluorochloroethylene; more preferably, the fluorinated organic compound is one or more selected from trifluoromethane, pentafluoroethane, difluoroethylene, and difluorochloromethane.

[0071] Preferably, the hydrogen chloride gas containing fluorinated organic compounds has a fluorinated organic compound content of 0.0001-10% by volume, more preferably 0.1-5% by volume, and even more preferably 0.5-3% by volume.

[0072] Preferably, the metal compound is one or more of metal oxides, hydroxides, chlorides, and chlorides.

[0073] Preferably, the metal in the metal compound is selected from one or more of aluminum, gallium, tin, iron, vanadium, chromium, zirconium, niobium, antimony, zinc, cobalt, nickel and indium, more preferably aluminum and / or zirconium.

[0074] Preferably, the metal compound is one or more of aluminum oxide, aluminum hydroxide, aluminum chloride, hydrated aluminum hydroxide, aluminum oxychloride, and zirconium oxide, zirconium oxychloride, and zirconium hydroxide; more preferably, the metal compound is one or more of aluminum oxide, aluminum oxychloride, aluminum hydroxide, zirconium oxychloride, and zirconium oxide.

[0075] Preferably, the particle size of the metal compound is 0.001-5 mm; more preferably, the particle size of the metal compound is 0.001-0.2 mm; or even more preferably, the particle size of the metal compound is 0.1-5 mm.

[0076] Preferably, in step 1), the conditions for the first contact include: a temperature of 50-750°C and a volume hourly space velocity (VHSV) of 1-10000 h⁻¹ for the raw material. -1 More preferably, the conditions for the first contact include: a temperature of 360-460°C and a volume hourly space velocity (VHSV) of 50-1000 h⁻¹ for the raw material. -1 .

[0077] Preferably, the first contact is carried out under conditions free of water vapor.

[0078] Preferably, the first contact is carried out under oxygen-free conditions.

[0079] Preferably, in step 2), the conditions for the second contact include: a temperature of 280-420°C; and a molar ratio of hydrogen chloride to oxygen in the defluorination raw material of 0.25-10:1. More preferably, the conditions for the second contact include: a temperature of 320-390°C; and a molar ratio of hydrogen chloride to oxygen in the defluorination raw material of 0.5-4:1.

[0080] Preferably, the temperature of the first contact is 0-180°C higher than the temperature of the second contact.

[0081] Preferably, step 1) further includes: a step of removing HF from the gaseous product obtained after the first contact; and / or a step of removing CO from the gaseous product obtained after the first contact.

[0082] A fourth aspect of the present invention provides a method for preparing a metal fluoride, wherein the method comprises: contacting a fluorine-containing organic compound with a metal compound in the presence of hydrogen chloride, wherein the metal compound contains an L acid in the presence of hydrogen chloride.

[0083] Preferably, the fluorinated organic compound is a fluorinated hydrocarbon with 1-8 carbon atoms, more preferably a fluorinated hydrocarbon with 1-4 carbon atoms, and even more preferably a fluorinated hydrocarbon with 1-2 carbon atoms.

[0084] Preferably, the fluorinated organic compound is represented by the following formula (1) or formula (2):

[0085] C n H x F y Cl z Equation (1);

[0086] C m Ho F p Cl q Equation (2);

[0087] In formula (1), n ​​is an integer from 1 to 8, preferably from 1 to 4, and more preferably 1 or 2;

[0088] x and z are both integers greater than or equal to 0, y is an integer greater than or equal to 1, and x + y + z = 2n + 2.

[0089] In equation (2), m is an integer from 2 to 8, preferably from 2 to 4, and more preferably 2;

[0090] o and q are both integers greater than or equal to 0, p is an integer greater than or equal to 1, and o + p + q = 2n.

[0091] Preferably, the fluorinated organic compound is one or more selected from monofluoromethane, difluoromethane, trifluoromethane, difluorochloromethane, difluoroethane, trifluoroethane, tetrafluoroethane, pentafluoroethane, difluorochloroethane, pentafluorochloroethane, difluoroethylene, tetrafluoroethylene, and trifluorochloroethylene; more preferably, the fluorinated organic compound is one or more selected from trifluoromethane, pentafluoroethane, difluoroethylene, and difluorochloromethane.

[0092] Preferably, the metal compound is one or more of metal oxides, hydroxides, chlorides, and chlorides.

[0093] Preferably, the metal in the metal compound is selected from one or more of aluminum, gallium, tin, iron, vanadium, chromium, zirconium, niobium, antimony, zinc, cobalt, nickel and indium, more preferably aluminum and / or zirconium.

[0094] Preferably, the metal compound is one or more of aluminum oxide, aluminum hydroxide, aluminum chloride, aluminum oxychloride, zirconium oxide, zirconium oxychloride, and zirconium hydroxide; more preferably, the metal compound is one or more of aluminum oxide, aluminum oxychloride, aluminum hydroxide, zirconium oxychloride, and zirconium oxide.

[0095] More preferably, the metal compound is one or more of aluminum oxide, aluminum oxide chloride, and aluminum hydroxide, and the metal fluoride is aluminum fluoride.

[0096] Preferably, the particle size of the metal compound is 0.001-5 mm; more preferably, the particle size of the metal compound is 0.001-0.2 mm, or even more preferably, the particle size of the metal compound is 0.1-5 mm.

[0097] Preferably, the contact conditions include: a temperature of 50-750°C and a volume hourly space velocity (VHSV) of 1-10000 h⁻¹ for the mixed gas of fluorinated organic compounds and hydrogen chloride. -1More preferably, the contact conditions include: a temperature of 350-500°C and a volume hourly space velocity (VHSV) of 50-1000 h⁻¹ for the mixed gas of fluorinated organic compounds and hydrogen chloride. -1 .

[0098] Preferably, the contact is carried out under conditions free of water vapor.

[0099] Preferably, the contact is carried out under oxygen-free conditions.

[0100] Preferably, the method includes: in the presence of hydrogen chloride, contacting a fluorinated organic compound with one or more selected from alumina, aluminum hydroxide, aluminum oxide chloride, and aluminum chloride to prepare aluminum fluoride.

[0101] Preferably, the method includes: contacting a mixture of a fluorinated organic compound and hydrogen chloride with one or more selected from alumina, aluminum hydroxide and aluminum oxide chloride to prepare aluminum fluoride.

[0102] The above technical solution can achieve the following beneficial effects:

[0103] 1) The method for treating fluorinated organic compounds provided by this invention is very simple and easy to implement. It only requires contacting the fluorinated organic compounds with a specific metal compound in the presence of hydrogen chloride. It can universally treat various fluorinated organic compounds without the need to prepare a catalyst in advance or introduce oxygen and water vapor to participate in the reaction. The fluorinated organic compounds can be removed (removed to below 0.01 ppm), and the treatment effect of fluorinated organic compounds is excellent.

[0104] 2) The method provided by this invention can effectively solve the problem of disposal of by-product hydrogen chloride produced by organic fluorine chemical industry in the prior art. It can economically and efficiently remove various fluorine-containing organic compounds in by-product hydrogen chloride, and can also remove inorganic fluorides such as sulfur hexafluoride and sulfur tetrafluoride under suitable conditions, thereby obtaining purified hydrogen chloride gas.

[0105] 3) Furthermore, by adopting the method provided by the present invention, the existing technical bottleneck of not being able to use hydrogen chloride, a by-product of organofluorine chemical industry, to prepare chlorine can be overcome, and industrial chlorine production can be achieved using hydrogen chloride containing fluorine-containing organic compounds as raw material. The production can be carried out stably and continuously for a long time without causing carbon buildup.

[0106] 4) In addition, by using the method provided by the present invention, during the reaction of fluorinated organics with metal compounds, the fluorine in the fluorinated organics is fixed and resource-utilized in the form of metal fluorides, which significantly reduces the carbon deposits and coverings formed by fluorinated organics in molecular form on the surface of metal compounds, and the reaction activity is basically not reduced during the reaction process. Once the reaction is initiated, it can proceed stably for a long time until the metal compound is completely fluorinated.

[0107] 5) On the other hand, the method provided by this invention can, while treating fluorinated organic compounds, produce high-value-added products such as aluminum fluoride, depending on the type of metal compound selected. By controlling the reaction conditions, the aluminum fluoride obtained can have an F content of up to 61% (mass fraction) or more, an aluminum content of up to 31.5% (mass fraction) or more, and a fluorine-aluminum mass fraction ratio of up to 1.93. Moreover, the quality of the aluminum fluoride meets the chemical composition requirements specified for grade AF-0 in GB / T 4292-2017. This not only solves the problem of treating hydrogen chloride containing fluorinated organic compounds, but also enables the preparation of high-value metal fluorides, resulting in significant economic benefits.

[0108] 6) When using the method provided by this invention to prepare chlorine, there is no need to purchase a complete set of production equipment. Only minor improvements are needed to the existing hydrogen chloride to chlorine equipment. The equipment investment cost is low and the applicability is wide. Attached Figure Description

[0109] Figure 1 The XPS total spectrum of the solid substance prepared in Example 1;

[0110] Figure 2 The F-spectrum is shown for the solid material prepared in Example 1. Detailed Implementation

[0111] While the background section describes the inventors' preliminary experiments and explorations related to this invention, it should be understood that these descriptions are merely for the sake of fluency and to facilitate a better understanding of the technical problems and solutions of this invention by those skilled in the art. Therefore, the inventors' experiments and discoveries described in the background section should also be considered contributions to this invention and should not be construed as being included in the prior art simply because they are described in the background section.

[0112] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0113] First, the fluorinated organic compounds described in this invention will be explained and defined.

[0114] Unless otherwise specified, the fluorinated organics involved in this invention refer to organic compounds in which hydrogen atoms bonded to carbon atoms in the molecule are replaced by fluorine. These include perfluorinated organic compounds in which all carbon-hydrogen bonds in the molecule are converted into carbon-fluorine bonds, as well as monofluorinated or polyfluorinated organic compounds in which some carbon-hydrogen bonds are converted into carbon-fluorine bonds.

[0115] That is, the fluorinated organic compound described in this invention is a perfluorinated organic compound or a non-perfluorinated organic compound, wherein a non-perfluorinated organic compound is preferred.

[0116] In addition, in this invention, the fluorinated organic compounds include, but are not limited to, fluorinated alkanes, fluorinated alkenes, fluorinated aromatics, and fluorinated carboxylic acids.

[0117] In this invention, there is no particular limitation on the number of carbon atoms in the fluorinated organic compound. Preferably, the number of carbon atoms in the fluorinated organic compound is 1-8, more preferably 1-6, further preferably 1-4, and particularly preferably 1 or 2.

[0118] In addition, in this invention, the fluorinated organic compound is preferably a fluorinated organic compound in the gas phase under normal temperature and pressure conditions, where normal temperature and pressure refers to conditions of 25°C and 101 kPa.

[0119] In some embodiments of the present invention, the fluorinated organic compound is preferably a fluorinated hydrocarbon, more preferably a fluorinated alkane or a fluorinated olefin.

[0120] The aforementioned fluorinated alkanes can be represented by the following formula (1):

[0121] C n H x F y Cl z Equation (1);

[0122] In formula (1), n ​​is an integer from 1 to 8, preferably from 1 to 4, and more preferably 1 or 2;

[0123] x and z are both integers greater than or equal to 0, y is an integer greater than or equal to 1, and x + y + z = 2n + 2.

[0124] The above-mentioned fluorinated olefin can be represented by the following formula (2):

[0125] C m H o F p Cl q Equation (2);

[0126] In equation (2), m is an integer from 2 to 8, preferably from 2 to 4, and more preferably 2;

[0127] o and q are both integers greater than or equal to 0, p is an integer greater than or equal to 1, and o + p + q = 2n.

[0128] In equations (1) and (2) above, C represents a carbon atom, H represents a hydrogen atom, F represents a fluorine atom, and Cl represents a chlorine atom.

[0129] In this invention, the fluorinated organic compounds include, among others, monofluoromethane, difluoromethane, trifluoromethane, tetrafluoromethane, monofluorochloromethane, monofluorodichloromethane, monofluorotrichloromethane, difluorochloromethane, difluorodichloromethane, trifluorochloromethane, monofluoroethane, difluoroethane, trifluoroethane, tetrafluoroethane, pentafluoroethane, hexafluoroethane, monochlorofluoroethane, monochlorodifluoroethane, monochlorotrifluoroethane, monochlorotetrafluoroethane, monochloropentafluoroethane, dichlorofluoroethane, dichlorodifluoroethane, dichlorotrifluoroethane, dichlorotetrafluoroethane, trichlorofluoroethane, trichlorodifluoroethane, trichlorotrifluoroethane, tetrachlorofluoroethane, tetrachlorodifluoroethane, pentachlorofluoroethane, tetrafluoroethylene, trifluoroethylene, difluoroethylene, fluorinated vinylene, trifluorochloroethylene, and dichlorodifluoroethylene.

[0130] According to the present invention, preferably, the fluorinated organic compound is one or more selected from monofluoromethane, difluoromethane, trifluoromethane, difluorochloromethane, difluoroethane, trifluoroethane, tetrafluoroethane, pentafluoroethane, difluorochloroethane, pentafluorochloroethane, difluoroethylene, tetrafluoroethylene, and trifluorochloroethylene.

[0131] In some particularly preferred embodiments of the present invention, the fluorinated organic compound is one or more of trifluoromethane, pentafluoroethane, difluoroethylene, and difluorochloromethane.

[0132] Next, the metal compounds described in this invention will be explained and defined.

[0133] According to the present invention, the metal compound exhibits L-acidity in the presence of hydrogen chloride.

[0134] In this invention, the L-acid refers to a Lewis acid, which is an acid as defined in the Lewis acid-base theory. According to the definition of this theory, an L-acid (Lewis acid) is a substance (including ions, atomic groups, or molecules) that can accept electron pairs.

[0135] In this invention, L-acid accepts electron pairs to form chemical bonds with reactants, thereby activating the reactants, promoting the reaction, and consequently affecting the reaction pathway and product distribution.

[0136] In this invention, the presence of L-acid under the action of hydrogen chloride can be determined by pyridine adsorption infrared spectroscopy. Specifically, a metal compound sample is self-supported and pressed into a pellet, placed in the in-situ cell of an infrared spectrometer, hydrogen chloride gas is introduced and kept sealed, heated to 350°C and maintained at this temperature for 30 minutes; then a vacuum is drawn to 10... -3The sample was kept at a constant temperature of 1 Pa for 1 hour to remove the physically adsorbed hydrogen chloride gas from the sample surface; after cooling to room temperature, pyridine vapor was introduced to maintain adsorption equilibrium for 30 minutes, then the temperature was raised to 200°C, and the vacuum was re-evacuated to 10 Pa. -3 Pa was desorbed under this vacuum for 30 minutes, then cooled to room temperature for spectral analysis, with a scanning range of 1400-1700 cm⁻¹. -1 If 1450±5cm is observed. -1 The presence of a characteristic peak indicates that the metal compound contains L-acid under the influence of hydrogen chloride.

[0137] Through experiments, the inventors have confirmed that metal compounds exhibiting L-acidity under the action of hydrogen chloride, as determined by the above-mentioned testing methods, meet the property requirements of the present invention for the metal compounds and can be applied to the methods described in the following aspects to achieve the corresponding inventive objectives. The test conditions in the above-mentioned testing methods do not limit the application of the present invention.

[0138] Furthermore, although theoretically, the L acid can be inherent in the metal compound itself or can be produced after contact with hydrogen chloride, this invention does not focus on this. As long as the L acid can be detected by the above-described test method of this invention, such a metal compound can achieve the purpose of this invention. Therefore, the above situations are all included in the scope of this invention, and this invention does not conduct a specific investigation in this regard.

[0139] In this invention, preferably, the metal compound is one or more of metal oxides, hydroxides, chlorides, and chlorides.

[0140] Furthermore, in this invention, preferably, the metal in the metal compound is selected from one or more of aluminum, gallium, tin, iron, vanadium, chromium, zirconium, niobium, antimony, zinc, cobalt, nickel, and indium, more preferably aluminum and / or zirconium.

[0141] Preferably, the metal compound is one or more of aluminum oxide, aluminum hydroxide, hydrated aluminum hydroxide, aluminum chloride, aluminum oxychloride, zirconium oxide, zirconium oxychloride, and zirconium hydroxide.

[0142] More preferably, the metal compound is one or more of aluminum oxide, zirconium oxychloride, aluminum oxychloride, zirconium oxide, and aluminum hydroxide.

[0143] In a particularly preferred embodiment of the present invention, the metal compound is aluminum oxide.

[0144] Furthermore, when alumina is used, it can be one or more of any crystalline form of alumina, without particular limitation. However, β-alumina and / or γ-alumina are preferred for better reactivity.

[0145] In yet another particularly preferred embodiment of the invention, the metal compound is aluminum hydroxide.

[0146] In addition, the present invention does not impose any particular limitations on the particle size of the metal compound, etc., and those skilled in the art can make appropriate selections according to actual needs.

[0147] In this invention, in order to increase the contact area with fluorinated organic compounds and thus facilitate their decomposition, the particle size of the metal compound is preferably 0.001-5 mm.

[0148] Furthermore, the particle size of the metal compound can be appropriately optimized according to actual process requirements. For example, when using a fluidized bed reactor, the particle size of the metal compound is preferably 0.001-0.2 mm, in which case the metal compound is in the form of microspheres, which is beneficial to improving its fluidity in the reaction and thus improving the reaction efficiency; when using a fixed bed or moving bed reactor, the particle size of the metal compound is preferably 0.1-5 mm, in which case the metal compound is in the form of small spheres, which is convenient for replacement and other operations.

[0149] Those skilled in the art will understand that the above-defined particle size range is made from the perspective of process and operability, and the metal compounds described in this invention are not limited by particle size.

[0150] The foregoing has defined and described the fluorinated organic compounds and metal compounds in this invention, and the foregoing definition and description apply to all aspects of the invention to be described below. That is, unless otherwise stated, the fluorinated organic compounds and metal compounds involved in the following aspects of the invention are as described above, and will not be repeated hereafter.

[0151] The first aspect of the present invention provides a method for treating fluorinated organic compounds, wherein the method includes: contacting the fluorinated organic compounds with a metal compound in the presence of hydrogen chloride to generate a metal fluoride, wherein the metal compound contains an L acid in the presence of hydrogen chloride.

[0152] According to a specific embodiment of the present invention, a method for treating fluorinated organic compounds is provided. The method includes: contacting the fluorinated organic compounds with a metal compound in the presence of hydrogen chloride to generate a metal fluoride, wherein the metal compound is one or more selected from metal oxides, hydroxides, chlorides, and chlorides, and the metal in the metal compound is selected from one or more selected from aluminum, gallium, tin, iron, vanadium, chromium, zirconium, niobium, antimony, zinc, cobalt, nickel, and indium.

[0153] According to a first aspect of the present invention, the treatment method does not have particular requirements on the relative amounts of hydrogen chloride and fluorine-containing organic compounds; the presence of hydrogen chloride is sufficient to initiate the reaction, causing the fluorine-containing organic compounds to be decomposed by the metal compound. Therefore, the first aspect of the present invention does not limit the amount of hydrogen chloride used, as long as the presence of hydrogen chloride allows the fluorine-containing organic compounds to come into contact with the metal compound.

[0154] According to the present invention, the molar ratio of the hydrogen chloride to the fluorine-containing organic compound can be, for example, 1:0.001-10000.

[0155] In addition, in a preferred embodiment of the present invention, the method for treating the fluorinated organic matter includes: contacting a mixture of the fluorinated organic matter and hydrogen chloride with the metal compound to remove the fluorinated organic matter and generate a metal fluoride.

[0156] In the mixture of fluorinated organic compound and hydrogen chloride, the content of the fluorinated organic compound is not particularly limited and can be determined according to the composition of the raw material gas. For example, the content of the fluorinated organic compound in the mixture can be 0.0001-99% by volume, preferably 1-99% by volume, for example, specifically 1% by volume, 50% by volume, 80% by volume, and any two of these values, with the balance being hydrogen chloride.

[0157] Furthermore, according to the first aspect of the invention, the treatment method does not have particular requirements regarding the relative amounts of the metal compound and the fluorinated organic compound. It is understood that when the goal is the decomposition and removal of the fluorinated organic compound, the metal compound can be used in excess. Those skilled in the art can determine the relative amounts of the two according to actual needs, and this is not limited in this invention.

[0158] According to the present invention, the contact conditions are designed to enable the reaction and decomposition of the fluorinated organic compound with the metal compound. For example, the contact temperature can be 50-750°C. Furthermore, the volume hourly space velocity (VHSV) of the mixed gas of the fluorinated organic compound and hydrogen chloride can be 1-10000 h⁻¹. -1 Preferably, the contact conditions include: a temperature of 300-500°C and a volume hourly space velocity (VHSV) of 50-1000 h⁻¹ for the mixed gas of fluorinated organic compound and hydrogen chloride. -1 Therefore, the decomposition efficiency of fluorinated organic compounds can be further improved, and the treatment effect of fluorinated organic compounds can be further enhanced.

[0159] In this invention, the volumetric space velocity refers to the amount of mixed gas processed per unit volume of metal compound per unit time, and the unit is m. 3 / (m 3 Metal compounds (h).

[0160] Furthermore, in order to reduce the formation of byproducts such as oxygen-containing fluorides and their impact on the degree of metal fluorination, the contact is preferably carried out under conditions free of water vapor.

[0161] In this invention, "free of water vapor" means that no additional water vapor is introduced, and the water vapor content does not exceed 0.5% by volume, calculated based on the total volume of the hydrogen chloride and fluorine-containing organic matter as 100% by volume.

[0162] In this invention, in order to reduce the generation of byproducts such as oxygen-containing fluorides and their impact on the degree of metal fluorination, the contact is preferably carried out under oxygen-free conditions.

[0163] In this invention, "oxygen-free" means that no additional oxygen is introduced, and the oxygen content does not exceed 0.5% by volume, calculated based on the total volume of the hydrogen chloride and fluorine-containing organic matter as 100% by volume.

[0164] According to a preferred embodiment of the first aspect of the present invention, the metal compound is one or more selected from aluminum oxide, aluminum oxychloride, aluminum hydroxide, zirconium oxychloride, and zirconium oxide.

[0165] According to a preferred embodiment of the first aspect of the present invention, the fluorinated organic compound is one or more selected from trifluoromethane, pentafluoroethane, difluoroethylene, and difluorochloromethane.

[0166] The method provided by the first aspect of this invention can efficiently decompose fluorinated organic compounds in the presence of hydrogen chloride, while simultaneously fixing fluorine in the form of metal fluorides. This not only overcomes the difficulties in treating fluorinated organic compounds but also enables the production of high-value-added metal fluorides such as aluminum fluoride, realizing the resource utilization of hazardous waste industrial byproducts.

[0167] Furthermore, the method provided in the first aspect of the present invention can remove fluorinated organic compounds to a level that is undetectable by a gas chromatograph, with a detection limit (minimum concentration to be detected) of 0.01 ppm.

[0168] A second aspect of the present invention provides a method for purifying hydrogen chloride gas containing fluorine-containing organic compounds, wherein the purification method includes: contacting the hydrogen chloride gas containing fluorine-containing organic compounds with a metal compound to remove the fluorine-containing organic compounds from the hydrogen chloride and generate a metal fluoride, wherein the metal compound contains L acid under the action of hydrogen chloride.

[0169] According to a specific embodiment of the present invention, a method for purifying hydrogen chloride gas containing fluorine-containing organic compounds is provided. The purification method includes: contacting the hydrogen chloride gas containing fluorine-containing organic compounds with a metal compound to remove the fluorine-containing organic compounds from the hydrogen chloride and generate a metal fluoride. The metal compound is one or more selected from metal oxides, hydroxides, chlorides, and chlorides. The metal in the metal compound is selected from one or more selected from aluminum, gallium, tin, iron, vanadium, chromium, zirconium, niobium, antimony, zinc, cobalt, nickel, and indium.

[0170] According to a second aspect of the present invention, the hydrogen chloride gas containing fluorinated organic compounds can be a byproduct of organic fluorine chemical production processes. For example, it can come from fluoropolymer production processes, fluorinated refrigerant preparation processes, fluorinated solvent production processes, fluorinated pharmaceutical production processes, fluorinated pesticide production processes, and fluorinated surface lubricant production processes, etc. The present invention does not impose any particular limitation on the source of the hydrogen chloride gas containing fluorinated organic compounds.

[0171] Furthermore, those skilled in the art will understand that the specific composition of the hydrogen chloride gas containing fluorine-containing organic compounds is not particularly limited in this invention. Depending on its source, the hydrogen chloride gas may contain not only fluorine-containing organic compounds, but also conventional impurities such as HF and sulfur fluoride (e.g., sulfur hexafluoride, sulfur tetrafluoride). The processing method provided by this invention can also purify the aforementioned hydrogen chloride.

[0172] Furthermore, the inventors of this invention have discovered that, according to the method provided by this invention, in addition to fluorine-containing organic compounds, some inorganic fluorides (such as sulfur hexafluoride and sulfur tetrafluoride) contained in hydrogen chloride gas can also be decomposed and removed.

[0173] The hydrogen chloride gas containing fluorine-containing organic compounds, as described in the second aspect of this invention, may, for example, contain: 50-99.9 vol% HCl and 0.1-50 vol% of the fluorine-containing organic compound; or 80-99.5 vol% HCl and 0.01-10 vol% of the fluorine-containing organic compound; or 90-99.9 vol% HCl, 0.1-10 vol% of the fluorine-containing organic compound, and 0-1 vol% HF. Preferably, the hydrogen chloride gas containing fluorine-containing organic compounds contains: 95-99.9 vol% HCl, 0.1-5 vol% fluorine-containing organic compound, and 0-1 vol% HF.

[0174] The purification method for hydrogen chloride gas containing fluorine-containing organic compounds described in the second aspect of the present invention aims to remove fluorine-containing organic impurities from hydrogen chloride. The decomposition / removal mechanism of the fluorine-containing organic compounds is consistent with that of the first aspect of the present invention, that is, the hydrogen chloride gas containing fluorine-containing organic compounds is contacted with the metal compound to decompose the fluorine-containing organic compounds in the presence of hydrogen chloride, and the fluorine in the fluorine-containing organic compounds is fixed in the form of metal fluorides, thereby removing the fluorine-containing organic compounds from the hydrogen chloride gas and achieving the purification of hydrogen chloride.

[0175] It will be understood by those skilled in the art that, according to the second aspect of the invention, the metal compound may be used in excess for the purpose of removing fluorine-containing organic compounds from hydrogen chloride gas, and the invention does not limit this.

[0176] According to a second aspect of the invention, the contact conditions are designed to enable the reaction and decomposition of the fluorinated organic compound with the metal compound. For example, the contact temperature can be 50-750°C, and the volume hourly space velocity (VHSV) of the hydrogen chloride gas containing the fluorinated organic compound can be 1-10000 h⁻¹. -1 Preferably, the contact conditions include: a temperature of 300-500°C and a volume hourly space velocity (VHSV) of hydrogen chloride gas containing fluorine-containing organic compounds of 50-1000 h⁻¹. -1 Therefore, the decomposition efficiency of fluorinated organic compounds can be further improved, the purification level of hydrogen chloride gas can be increased, and the treatment effect of fluorinated organic compounds can be further enhanced.

[0177] According to the method provided in the second aspect of the present invention, organic fluorides in hydrogen chloride gas containing fluorine-containing organic compounds can be removed, thereby purifying hydrogen chloride, a by-product in organofluorine chemical industry, containing only trace amounts of CO, CO2, or HF. As needed, CO and HF can be removed by conventional means such as subsequent oxidation and adsorption treatments, respectively. The presence of a small amount of CO2 does not affect the subsequent reaction of hydrogen chloride to chlorine.

[0178] Furthermore, using the method provided in the second aspect of the present invention, fluorinated organic compounds in hydrogen chloride gas containing fluorinated organic compounds can be removed to a level that is undetectable by a gas phase spectrometer, with a detection limit (minimum detectable concentration) of 0.01 ppm.

[0179] A third aspect of this invention provides a method for preparing chlorine gas, which uses hydrogen chloride containing fluorine-containing organic compounds as a raw material to prepare chlorine gas, comprising the following steps:

[0180] 1) The raw material is brought into first contact with a metal compound to obtain a defluorination raw material;

[0181] 2) In the presence of a catalyst, the defluorinated feedstock obtained in step 1) is subjected to a second contact with oxygen.

[0182] The metal compound exhibits L-acidity under the action of hydrogen chloride, and the catalyst is a catalyst for the catalytic oxidation of hydrogen chloride to chlorine.

[0183] According to a specific embodiment of the present invention, a method for preparing chlorine gas is provided. This method uses hydrogen chloride containing fluorine-containing organic compounds as a raw material to prepare chlorine gas, and includes the following steps:

[0184] 1) The raw material is brought into first contact with a metal compound to obtain a defluorination raw material;

[0185] 2) In the presence of a catalyst, the defluorinated feedstock obtained in step 1) is subjected to a second contact with oxygen.

[0186] The metal compound is one or more of metal oxides, hydroxides, chlorides, and chlorine oxides, and the metal in the metal compound is selected from one or more of aluminum, gallium, tin, iron, vanadium, chromium, zirconium, niobium, antimony, zinc, cobalt, nickel, and indium. The catalyst is a catalyst for the catalytic oxidation of hydrogen chloride to chlorine.

[0187] As mentioned above, the industrial production of chlorine using hydrogen chloride containing fluorine-containing organic compounds as a raw material using existing technologies presents significant difficulties. The reaction cannot proceed stably for extended periods, and noticeable carbon deposits form on the catalyst surface. The inventors of this invention, however, utilize a special hydrogen chloride atmosphere to decompose and remove fluorine-containing organic compounds from chlorine, thereby enabling the industrial production of chlorine using hydrogen chloride containing fluorine-containing organic compounds as a raw material.

[0188] The method for preparing chlorine gas provided in the third aspect of the present invention will be described in detail below.

[0189] The third aspect of the present invention prepares chlorine gas using hydrogen chloride gas containing fluorine-containing organic compounds as a raw material, the source and composition of which can be the same as those in the second aspect of the present invention. For example, in addition to fluorine-containing organic compounds and hydrogen chloride, the raw material may also contain other substances such as hydrogen fluoride, and the present invention does not limit this.

[0190] According to a third aspect of the present invention, the content of fluorinated organic compounds in the hydrogen chloride gas containing fluorinated organic compounds can be 0.0001-20% by volume, preferably 0.1-10% by volume, and more preferably 0.5-3% by volume.

[0191] Furthermore, the raw material described in the third aspect of the present invention may, for example, contain: 50-99.9 vol% HCl and 0.1-50 vol% of the fluorinated organic compound; or 80-99.5 vol% HCl and 0.01-10 vol% of the fluorinated organic compound; or 90-99.9 vol% HCl, 0.1-10 vol% of the fluorinated organic compound, and 0-1 vol% HF. Preferably, the raw material contains: 95-99.9 vol% HCl, 0.1-5 vol% fluorinated organic compound, and 0-100 ppm HF.

[0192] According to a third aspect of the invention, in step 1), the raw material is first contacted with a metal compound to obtain a defluorinated raw material. This step aims to eliminate the influence of fluorinated organic matter on the catalyst subsequently used for the catalytic oxidation of hydrogen chloride to chlorine, decompose the fluorinated organic matter contained in hydrogen chloride, and fix it in the form of the corresponding metal fluoride.

[0193] According to a third aspect of the present invention, the first contact only needs to be capable of decomposing fluorinated organic compounds, and there are no particular requirements. For example, the conditions of the first contact may include: a temperature of 50-750°C, and a volume hourly space velocity (VHSV) of 1-10000 h⁻¹ for the raw material (hydrogen chloride gas containing fluorinated organic compounds). -1 Preferably, the conditions for the first contact include: a temperature of 300-460°C and a volume hourly space velocity (VHSV) of 10-1000 h⁻¹ for the raw material. -1 More preferably, the conditions for the first contact include: a temperature of 360-460°C and a volume hourly space velocity (VHSV) of 50-1000 h⁻¹ for the raw material. -1 .

[0194] The preferred temperature conditions for the first contact described above not only efficiently decompose fluorinated organic compounds, but also match the activity temperature of the catalyst used in step 2) for producing chlorine from hydrogen chloride, eliminating the need for further temperature adjustments between the first and second contacts. In other words, by employing the preferred conditions for the first contact, the defluorinated feedstock obtained in step 1) can directly participate in the reaction in the second contact in step 2) without temperature adjustment. This significantly reduces energy consumption, improves energy efficiency, and reduces operational complexity at the industrial level.

[0195] Furthermore, it is understood that step 1) of the third aspect of the present invention is actually similar in purpose and specific operation method to the purification of hydrogen chloride gas containing fluorine-containing organic compounds described in the second aspect of the present invention. Unless otherwise specified, the conditions and specific selections of step 1) of the third aspect of the present invention can be performed with reference to the second aspect of the present invention.

[0196] Furthermore, according to the present invention, since the presence of water increases the generation of oxygen-containing fluorides and reduces the equilibrium conversion rate of subsequent hydrogen chloride to chlorine, the first contact is preferably carried out under conditions free of water vapor.

[0197] Furthermore, since the formation of oxygen-containing fluorides increases in an oxygen atmosphere, the first contact is preferably carried out under oxygen-free conditions.

[0198] In the third aspect of this invention, the definitions of "free from water vapor" and "free from oxygen" are the same as those in the first aspect of this invention, and will not be repeated here.

[0199] In this invention, as described above, the raw materials may contain HF, and a small amount of HF may also be generated during the first contact. This portion of HF will be absorbed in situ by the corresponding metal compound during the first contact. After the first contact, HF is generally no longer present in the first contact product.

[0200] In addition, if the first contact product still contains HF, the gaseous product obtained from the first contact can be de-HF treated to remove the HF and avoid affecting the subsequent second contact, i.e., the preparation of chlorine.

[0201] Here, the HF removal treatment can be carried out using conventional methods in the art, without any particular limitation. For example, chemical adsorption or other methods can be used to remove HF from the gaseous products obtained in the first contact. The adsorbent used can be, for example, SCAF-10 hydrogen fluoride adsorbent produced by Sinopec Catalyst Co., Ltd. This is a conventional operation in the art and will not be described in detail here.

[0202] It is understood that when the above-mentioned HF removal treatment is carried out, the defluorination raw material mentioned in step 2) is the product after the HF removal treatment.

[0203] Furthermore, in this invention, a very small amount of CO may also be generated through the aforementioned first contact. Therefore, preferably, the method may further include a step of removing CO from the gaseous product obtained after the first contact.

[0204] Here, the CO removal treatment can be carried out using various conventional CO removal methods in the art, without any particular limitation. For example, a carbon monoxide treatment catalyst can be used to catalytically oxidize CO to CO2. More specifically, the SCCC-10 chlorine-resistant carbon monoxide treatment catalyst produced by Sinopec Catalyst Co., Ltd. can be used for CO removal treatment. The catalytic oxidation of carbon monoxide is a conventional operation in the art and will not be described in detail here.

[0205] It is understood that when performing the above-mentioned CO removal treatment, the defluorination raw material mentioned in step 2) is the product after CO removal treatment.

[0206] Furthermore, the CO2 generated during the CO removal process, or some of the CO2 present in the defluorination feedstock, will not have a significant negative impact on the subsequent production of chlorine from hydrogen chloride. Therefore, even if there is a small amount of CO2 in the defluorination feedstock, it is not necessary to remove it separately.

[0207] Thus, through step 1) above, fluorine-containing organic compounds in hydrogen chloride gas are removed, and unwanted substances such as HF and CO can be selectively removed further to obtain defluorinated raw materials.

[0208] Next, step 2) is performed, in which the defluorinated feedstock obtained in step 1) is brought into a second contact with oxygen in the presence of a catalyst. This step aims to prepare chlorine gas from the defluorinated hydrogen chloride.

[0209] In step 2) above, there are no special requirements for the catalyst. The catalyst can be any of the various catalysts conventionally used in the art for the catalytic oxidation of hydrogen chloride to produce chlorine. For example, the catalyst support can be alumina, and the active component can contain copper, rare earth, and alkali metal oxides, etc. In this invention, there are no special limitations on the catalyst; those skilled in the art can prepare it using conventional methods, or it can be obtained commercially.

[0210] Furthermore, in step 2), the conditions for the second contact may include: a temperature of 280-420°C; and a molar ratio of hydrogen chloride to oxygen in the defluorination raw material of 0.25-10:1. Preferably, the conditions for the second contact include: a temperature of 320-390°C; and a molar ratio of hydrogen chloride to oxygen in the defluorination raw material of 0.5-4:1. By conducting the second contact under the above conditions, the efficiency and yield of chlorine preparation can be further improved, and the conversion rate of hydrogen chloride can be increased.

[0211] Furthermore, in step 2) of this invention, oxygen needs to be introduced based on the defluorination raw material obtained in step 1). In specific industrial production processes, the temperature of the introduced oxygen is generally low. Considering the temperature reduction effect of the introduction of oxygen, in this invention, preferably, the temperature of the first contact is 0-180°C higher than the temperature of the second contact. This further optimizes the temperature matching between steps 1) and 2), eliminating the need for separate heat exchange treatment, significantly increasing operational convenience and reducing heat consumption.

[0212] According to a third aspect of the present invention, chlorine can be prepared using hydrogen chloride gas containing fluorine-containing organic compounds as a raw material. Since the inventors of the present invention have successfully decomposed and removed fluorine-containing organic compounds from hydrogen chloride, they have overcome the existing technical bottleneck that prevented the use of hydrogen chloride, a byproduct of organofluorine chemical industry, for chlorine preparation. This enables industrial chlorine production using hydrogen chloride gas containing fluorine-containing organic compounds as a raw material, and the fluorine-containing organic compounds do not affect the activity of the catalyst, allowing chlorine production to proceed stably for a long time without producing carbon deposits.

[0213] In addition, while processing fluorinated organic compounds, high-value-added products such as aluminum fluoride can also be prepared simultaneously. This not only solves the problem of treating hydrogen chloride containing fluorinated organic compounds, but also enables the preparation of high-value fluorides, resulting in significant economic benefits.

[0214] A fourth aspect of the present invention provides a method for preparing a metal fluoride, the method comprising: contacting a fluorine-containing organic compound with a metal compound in the presence of hydrogen chloride, wherein the metal compound contains an L acid in the presence of hydrogen chloride.

[0215] According to a specific embodiment of the present invention, a method for preparing a metal fluoride is provided. The method includes: contacting a fluorinated organic compound with a metal compound in the presence of hydrogen chloride, wherein the metal compound is one or more selected from metal oxides, hydroxides, chlorides, and chlorides, and the metal in the metal compound is selected from one or more selected from aluminum, gallium, tin, iron, vanadium, chromium, zirconium, niobium, antimony, zinc, cobalt, nickel, and indium.

[0216] In a preferred embodiment of the present invention, the method includes: contacting hydrogen chloride gas containing fluorine-containing organic matter with a metal compound to remove the fluorine-containing organic matter from the hydrogen chloride gas and generate a metal fluoride.

[0217] Furthermore, in a particularly preferred embodiment of the invention, the metal compound is an aluminum compound, more preferably aluminum oxide and / or aluminum hydroxide. Thus, not only are the metal compound raw materials inexpensive and readily available, but aluminum fluoride can also be prepared.

[0218] Aluminum fluoride has a wide range of industrial applications. For example, it can be used as a component of electrolytic baths in the aluminum smelting industry, as a high-quality flux and deoxidizer in the metallurgical industry, and as an important catalyst, flame retardant, and desiccant in the chemical industry. It can not only promote the progress of various chemical reactions, but also be used for drying various chemicals. It is a very important chemical raw material.

[0219] In existing technologies, aluminum fluoride is generally prepared through dry or wet processes, which are relatively complex. The preparation process requires the use of highly corrosive substances such as HF, which not only results in high production costs and complex processes, but also poses a threat to the health and safety of workers.

[0220] In this invention, by selecting aluminum compounds as the metal compounds, not only are the aluminum compound raw materials themselves inexpensive and readily available, but also the widely used aluminum fluoride can be prepared, further realizing the resource utilization of fluorine-containing organic compounds, significantly improving their economic benefits, and the production process is short and easy to operate.

[0221] On the other hand, as mentioned above, those skilled in the art should understand that when the purpose is to remove fluorinated organic compounds as much as possible, such as step 1) of the first, second and third aspects of the present invention, an excess of metal compounds can be provided to improve the decomposition and removal effect of fluorinated organic compounds; conversely, when the purpose is to prepare high-quality metal fluorides as efficiently as possible, such as the fourth aspect of the present invention, an excess of fluorinated organic compounds can be provided.

[0222] Therefore, in the fourth aspect of this invention, no particular limitation is placed on the amount of fluorinated organic compounds and metal compounds used, and those skilled in the art can make appropriate selections according to actual needs such as the purpose of the reaction. It should be understood by those skilled in the art that when the goal is to prepare metal fluorides, the reaction conditions can be appropriately adjusted, for example, by selecting raw materials with a higher content of fluorinated organic compounds, increasing the space velocity of the reaction raw materials, and maintaining the introduction of organic fluorides for a longer period of time. These conditions can be appropriately adjusted and selected by those skilled in the art, and these specific reaction conditions do not limit the scope of this invention.

[0223] Furthermore, the inventors of this invention have further discovered during practical research that if, while treating fluorinated organic compounds or purifying hydrogen chloride containing fluorinated organic compounds, it is also desirable to simultaneously achieve efficient preparation of metal fluorides, the fluorinated organic compounds or hydrogen chloride gas containing fluorinated organic compounds can be sequentially passed through two or more reactors (e.g., fixed-bed or moving-bed reactors) packed with the aforementioned metal compounds. During the continuous reaction process, the metal compounds in the reactor at the front end (the reactor that first contacts the fluorinated organic compounds) will achieve fluorination more quickly due to their initial contact with the fluorinated organic compounds with a higher content, thereby producing metal fluorides with a higher degree of fluorination more rapidly. Meanwhile, the metal compounds in the reactor at the rear end have a relatively lower degree of fluorination, and at this point, the processing capacity for fluorinated organic compounds remains strong, ensuring the decomposition and removal of the fluorinated organic compounds.

[0224] As the reaction proceeds, when the fluorinated organic matter in the front reactor is completely or highly fluorinated, the fluorinated metal obtained in the first reactor can be removed, and as needed, the less fluorinated metal compounds in the rear reactor can be moved forward sequentially; and / or the first reactor can be removed, and a reactor filled with new metal compounds can be connected at the end of the last reactor, etc.

[0225] As a specific implementation method, for example, two or more fixed-bed reactors can be used alternately, such that the front-end reactor aims to decompose fluorinated organic compounds as much as possible to prepare high-quality metal fluorides, while the back-end reactor aims to decompose and remove all fluorinated organic compounds.

[0226] Furthermore, the use of two or more reactors filled with metal compounds in series as mentioned in the above embodiments is only a preferred method. In addition, similar variations such as segmented filling of multiple metal compounds can also be used. These simple variations and alternatives are all included within the technical concept of the present invention.

[0227] Therefore, through the above embodiments, the treatment of fluorinated organic compounds or the purification of hydrogen chloride containing fluorinated organic compounds and the preparation of metal fluorides can be achieved simultaneously and efficiently.

[0228] Furthermore, according to a fourth aspect of the invention, the contact conditions may include: a temperature of 50-750°C and a volume hourly space velocity (VHSV) of 1-10000 h⁻¹ for the mixed gas of fluorinated organic compound and hydrogen chloride. -1 More preferably, the contact conditions include: a temperature of 350-500°C and a volume hourly space velocity (VHSV) of 50-1000 h⁻¹ for the mixed gas of fluorinated organic compounds and hydrogen chloride. -1 Therefore, under the above-mentioned preferred conditions, the preparation efficiency and quality of metal fluorides can be further improved.

[0229] Furthermore, preferably, the contact is carried out under conditions free of water vapor.

[0230] Furthermore, preferably, the contact is carried out under oxygen-free conditions.

[0231] The conditions for the absence of water vapor and oxygen described here are as above and will not be repeated here.

[0232] According to a particularly preferred embodiment of the present invention, the metal compound is aluminum oxide and / or aluminum hydroxide, and the method includes: contacting hydrogen chloride gas containing fluorine-containing organic compounds with aluminum oxide and / or aluminum hydroxide to prepare aluminum fluoride.

[0233] Therefore, aluminum fluoride, which has wide industrial applications and high demand, can be prepared using a simple method at low cost. Furthermore, the aluminum chloride prepared in this way can have an F content of over 61.0% by weight and an Al content of over 31.5% by weight, meeting the chemical composition requirements of AF-0 specified in GB / T 4292-2017. This not only solves the problem of treating hydrogen chloride containing fluorine-containing organic compounds but also enables the preparation of high-value fluorides, generating significant economic benefits.

[0234] This invention provides not only methods for treating fluorinated organic compounds, purifying hydrogen chloride containing fluorinated organic compounds, and preparing chlorine gas using hydrogen chloride containing fluorinated organic compounds as a raw material, but also a method for preparing metal fluorides. The mechanisms for removing fluorinated organic compounds are essentially similar: in the presence of hydrogen chloride, the fluorinated organic compounds react with specific metal compounds, thereby fixing the fluorine in the fluorinated organic compounds into metal fluorides, thus decomposing and removing the fluorinated organic compounds and generating the corresponding metal fluorides. Therefore, according to actual needs and production objectives, it is possible to efficiently decompose and remove fluorinated organic compounds, purify hydrogen chloride gas, realize the industrial production of chlorine gas using hydrogen chloride gas containing fluorinated organic compounds as a raw material, and also prepare metal fluorides.

[0235] The present invention will be described in detail below through embodiments, but the present invention is not limited to the following embodiments.

[0236] In the following examples and comparative examples, the metal compounds used were determined to have L-acid in the presence of hydrogen chloride by the pyridine adsorption infrared method described in the specification.

[0237] Tests showed that among the metal compounds used in the following examples and comparative examples, γ-alumina, aluminum hydroxide, zirconium oxychloride, and aluminum oxychloride all exhibited L-acid under the action of hydrogen chloride, while aluminum metaphosphate and copper aluminate did not exhibit L-acid under the action of hydrogen chloride.

[0238] In the following examples and comparative examples, the surface elemental content of metal fluorides was analyzed using X-ray photoelectron spectroscopy (XPS).

[0239] In the following application examples and comparative application examples, the catalyst used for the catalytic oxidation of hydrogen chloride to chlorine is the SCCR-20 catalyst produced by Sinopec Catalyst Co., Ltd.

[0240] In the following application examples, the conversion rate of hydrogen chloride was determined according to the following method.

[0241] 1) Analytical Methods

[0242] By analyzing the content of chlorine and hydrogen chloride in the gas exiting the reactor, the conversion rate of hydrogen chloride can be determined.

[0243] The iodometric method is used to determine chlorine gas. Chlorine gas is passed into a KI solution, producing I₂, which is then titrated with a standard sodium thiosulfate solution. A small amount of hydrogen chloride is also absorbed into the KI solution, requiring the addition of a standard NaOH solution containing HCl. The specific steps are as follows:

[0244] (1) Take an appropriate amount of analytical solution into an Erlenmeyer flask and add three drops of 1% starch indicator. The solution will turn blue at this time.

[0245] (2) After stirring, titration was performed with 0.1 mol / L Na2S2O3 standard solution. The following chemical reaction occurred in the conical flask during the titration process.

[0246] (3) When I2 reacts with Na2S2O3, the solution immediately changes from dark blue to colorless and transparent, indicating the titration endpoint has been reached. Record the initial reading V1 (mL) and the final reading V2 (mL) of the burette.

[0247] I₂ + 2Na₂S₂O₃ → 2NaI + Na₂S₄O₆

[0248] After the iodometric titration, the HCl content in the KI solution was determined by titrating with NaOH standard solution using the acid-base neutralization method.

[0249] (1) Add three drops of 1% phenolphthalein indicator to the conical flask after the iodometric titration has been completed, and keep the solution colorless and transparent;

[0250] (2) After stirring with a glass rod, titration was performed with a 0.1 mol / L NaOH standard solution. The following chemical reaction occurred during the titration process.

[0251] (3) When the solution changes from colorless and transparent to light red immediately, the titration endpoint is reached. Record the initial reading V3 (mL) and the final reading V4 (mL) of the burette.

[0252] NaOH + HCl → NaCl + H₂O

[0253] 2) Calculation method

[0254] Based on the titration analysis data, the amounts of Cl2 and HCl, and the conversion rate of HCl were further calculated using the following formulas:

[0255] Amount of Cl2:

[0256] Amount of HCl:

[0257] Conversion rate of HCl:

[0258] Example 1

[0259] 1.2 g of γ-alumina with a particle size of 0.15-0.18 mm was packed into a reaction tube. After heating to the reaction temperature of 370 °C, a mixed gas containing fluorinated organic matter and hydrogen chloride, specifically a mixture of CHF3 and HCl, was continuously introduced at this temperature. The CHF3 concentration was 1% by volume, with the remainder being HCl gas. The volume hourly space velocity (VHSV) of the mixed gas was 1000 h⁻¹. -1 .

[0260] After 1 hour of reaction, the gaseous products of the reaction were detected by gas chromatography at the outlet of the reaction tube. CHF3 was not detected by gas chromatography.

[0261] After 9 hours of reaction, the solid material in the reaction tube was removed, and its surface elemental content was analyzed by X-ray photoelectron spectroscopy (XPS). The results showed that the F content was 43.77% (mass fraction)% and the Al content was 25.47% (mass fraction)%. The F spectrum showed that F existed in the form of AlF3.

[0262] In addition, observation revealed no obvious carbon buildup on the surface of the solid material.

[0263] The XPS total spectrum obtained in Example 1 is as follows: Figure 1 As shown, the F spectrum obtained in Example 1 is as follows: Figure 2 As shown.

[0264] Example 2

[0265] 1.2 g of aluminum hydroxide with a particle size of 0.15-0.18 mm was packed into a reaction tube. After heating to the reaction temperature of 460 °C, a mixed gas containing fluorine-containing organic matter and hydrogen chloride was continuously introduced at this temperature. Specifically, it was a mixture of CHF3 and HCl, with CHF3 concentration of 50% by volume and the remainder being HCl gas. The volume hourly space velocity (VHSV) of the mixed gas was 100 h⁻¹. -1 .

[0266] After 0.5 h of reaction, the gaseous products of the reaction were detected by gas chromatograph at the outlet of the reaction tube. CHF3 was not detected by gas chromatograph.

[0267] After 9 hours of reaction, the solid material in the reaction tube was removed, and its surface elemental content was analyzed by X-ray photoelectron spectroscopy (XPS). The results showed that the F content was 61.7% (mass fraction) and the Al content was 31.6% (mass fraction). The quality met the chemical composition requirements of AF-0 in GB / T4292-2017.

[0268] The F spectrum shows that F exists in the form of AlF3.

[0269] In addition, observation revealed no obvious carbon buildup on the surface of the solid material.

[0270] Example 3

[0271] 1.2 g of zirconium oxychloride with a particle size of 0.15-0.18 mm was packed into a reaction tube. After heating to the reaction temperature of 500 °C, a mixed gas containing fluorine-containing organic matter and hydrogen chloride was continuously introduced at this temperature. Specifically, it was a mixture of CHF3 and HCl, with CHF3 concentration of 80% by volume and the remainder being HCl gas. The volume hourly space velocity (VHSV) of the mixed gas was 50 h⁻¹. -1 .

[0272] After 0.5 h of reaction, the gaseous products of the reaction were detected by gas chromatograph at the outlet of the reaction tube. CHF3 was not detected by gas chromatograph.

[0273] After 9 hours of reaction, the solid material in the reaction tube was removed and its surface elemental content was analyzed by X-ray photoelectron spectroscopy (XPS). The results showed that the F content was 44.2% (mass fraction) and the Zr content was 54.3% (mass fraction).

[0274] The F spectrum shows that F exists in the form of ZrF4.

[0275] In addition, observation revealed no obvious carbon buildup on the surface of the solid material.

[0276] Example 4

[0277] The procedure is carried out according to the method described in Example 1, except that...

[0278] The mixed gas of fluorine-containing organic compounds and hydrogen chloride is specifically a mixture of pentafluoroethane (C HF) and HCl, wherein the concentration of pentafluoroethane is 1% by volume, and the remainder is HCl.

[0279] After 1 hour of reaction, the gaseous products of the reaction were detected by gas chromatography at the outlet of the reaction tube. Pentafluoroethane was not detected by gas chromatography.

[0280] After 9 hours of reaction, the solid material in the reaction tube was removed and its surface elemental content was analyzed by X-ray photoelectron spectroscopy (XPS). The results showed that the F content was 36.1% (mass fraction) and the Al content was 24.7% (mass fraction).

[0281] The F spectrum shows that F exists in the form of AlF3.

[0282] In addition, observation revealed no obvious carbon buildup on the surface of the solid material.

[0283] Example 5

[0284] The procedure is carried out according to the method described in Example 1, except that...

[0285] The reaction temperature is 330℃.

[0286] After 1 hour of reaction, the gaseous products of the reaction were detected by gas chromatography at the outlet of the reaction tube. CHF3 was not detected by gas chromatography.

[0287] After 9 hours of reaction, the solid material in the reaction tube was removed, and its surface elemental content was analyzed by X-ray photoelectron spectroscopy (XPS). The results showed that the F content was 24.6% (mass fraction)% and the Al content was 30.1% (mass fraction). The F spectrum showed that F existed in the form of AlF3.

[0288] In addition, observation revealed no obvious carbon buildup on the surface of the solid material.

[0289] Example 6

[0290] The procedure was carried out according to the method described in Example 1, except that 1.2 g of γ-alumina was replaced with the same weight of aluminum chloride.

[0291] After 1 hour of reaction, the gaseous products of the reaction were detected by gas chromatography at the outlet of the reaction tube. CHF3 was not detected by gas chromatography.

[0292] After 9 hours of reaction, the solid material in the reaction tube was removed, and its surface elemental content was analyzed by X-ray photoelectron spectroscopy (XPS). The results showed that the F content was 44.9% (mass fraction)% and the Al content was 26.8% (mass fraction)%. The F spectrum showed that F existed in the form of AlF3.

[0293] In addition, observation revealed no obvious carbon buildup on the surface of the solid material.

[0294] Example 7

[0295] The method described in Example 1 is followed, except that the mixed gas containing fluorine-containing organic compounds and hydrogen chloride is specifically a mixed gas of difluoroethylene (CHF) and HCl, wherein the concentration of CHF is 1% by volume, and the remainder is HCl.

[0296] After 1 hour of reaction, the gaseous products of the reaction were detected by gas chromatography at the outlet of the reaction tube. Difluoroethylene was not detected by gas chromatography.

[0297] After 9 hours of reaction, the solid material in the reaction tube was removed, and its surface elemental content was analyzed by X-ray photoelectron spectroscopy (XPS). The results showed that the F content was 32.8% (mass fraction)% and the Al content was 28.91% (mass fraction). The F spectrum showed that F existed in the form of AlF3.

[0298] In addition, observation revealed no obvious carbon buildup on the surface of the solid material.

[0299] Example 8

[0300] The method described in Example 1 is followed, except that the mixed gas containing fluorine-containing organic compounds and hydrogen chloride is specifically a mixed gas of difluorochloromethane (CHClF) and HCl, wherein the concentration of CHClF is 1% by volume, and the remainder is HCl.

[0301] After 1 hour of reaction, the gaseous products of the reaction were detected by gas chromatography at the outlet of the reaction tube. Difluorochloromethane was not detected by gas chromatography.

[0302] After 9 hours of reaction, the solid material in the reaction tube was removed and its surface elemental content was analyzed by X-ray photoelectron spectroscopy (XPS). The results showed that the F content was 31.5% (mass fraction) and the Al content was 27.5% (mass fraction).

[0303] The F spectrum shows that F exists in the form of AlF3.

[0304] In addition, observation revealed no obvious carbon buildup on the surface of the solid material.

[0305] Example 9

[0306] The procedure was carried out in accordance with Example 1, except that the concentration of CHF3 was increased from 1 vol% to 5 vol%, with the remainder being HCl.

[0307] After 1 hour of reaction, the gaseous products of the reaction were detected by gas chromatography at the outlet of the reaction tube. CHF3 was not detected by gas chromatography.

[0308] Four hours after the reaction, the solid material in the reaction tube was removed, and its surface elemental content was analyzed by X-ray photoelectron spectroscopy (XPS). The results showed that the F content was 61.5% (mass fraction) and the Al content was 31.6% (mass fraction). The quality met the chemical composition requirements of AF-0 in GB / T4292-2017.

[0309] The F spectrum shows that F exists in the form of AlF3.

[0310] In addition, observation revealed no obvious carbon buildup on the surface of the solid material.

[0311] Example 10

[0312] 7.2 g of γ-alumina with a particle size of 0.15-0.18 mm was divided into 6 equal portions. The reaction tube was then divided into 6 equal sections according to its length. Each section was filled with one portion of γ-alumina. After heating to the reaction temperature of 370 °C, a mixture of CHF3 and HCl was continuously introduced at this temperature. The CHF3 concentration was 1% by volume, with the remainder being HCl gas. The volume hourly space velocity (VHSV) of the mixed gas was 1000 h⁻¹. -1 .

[0313] After 16 hours of reaction, the gaseous products of the reaction were detected by gas chromatography at the outlet of the reaction tube. CHF3 was not detected by gas chromatography.

[0314] After 16 hours of reaction, the first and sixth sections of solid material were removed from the reaction tube (the section closest to the gas inlet of the reaction tube is the first section, and so on), and their surface elemental content was analyzed by X-ray photoelectron spectroscopy (XPS). The results showed:

[0315] In the first solid material, the F content is 61.8% (mass fraction) and the Al content is 31.9% (mass fraction).

[0316] In the sixth paragraph, the solid substance has an F content of 0.09% (mass fraction) and an Al content of 51.2% (mass fraction).

[0317] In the first segment of the solid material, the F spectrum shows that F exists entirely in the form of AlF3. In the sixth segment of the solid material, the F content is very low, and the F spectrum signal is weak.

[0318] In addition, observation revealed that no obvious carbon deposits were observed on the surface of any of the solid materials.

[0319] This demonstrates that by using a series loading method and ensuring a sufficient amount of metal compound, the metal compound at the inlet can be almost completely fluorinated, resulting in high-quality metal fluorides, while no fluorinated organic compounds can be detected at the outlet.

[0320] This method ensures the complete removal of fluorinated organic compounds and allows for the preparation of high-quality metal fluorides.

[0321] Comparative Example 1

[0322] The procedure is carried out according to the method described in Example 1, except that...

[0323] The mixture of CHF3 and hydrogen chloride is replaced with CHF3 and nitrogen, i.e., CHF3 is 1% by volume, and the remainder is nitrogen.

[0324] After 1 hour of reaction, the gaseous products were measured by gas chromatography at the outlet of the reaction tube. The results showed that the content of CHF3 in the gaseous products was 0.87% by volume.

[0325] After 9 hours of reaction, the solid material in the reaction tube was removed and its surface elemental content was analyzed by X-ray photoelectron spectroscopy (XPS). The results showed that the F content was 9.3% (mass fraction) and the Al content was 32.9% (mass fraction).

[0326] The F spectrum shows that F exists in the form of AlF3.

[0327] In addition, observation revealed that the surface of the solid material was grayish-black with obvious carbon deposits.

[0328] The results showed that in the absence of HCl, the reaction degree between γ-alumina and CHF3 was low, and it was difficult to effectively remove CHF3 even before the γ-alumina was completely fluorinated, and it was also difficult to prepare aluminum fluoride.

[0329] Comparative Example 2

[0330] The procedure is carried out according to the method described in Example 1, except that...

[0331] Replace the metal compound γ-alumina with an equal weight of aluminum metaphosphate.

[0332] After 1 hour of reaction, the gaseous products of the reaction were detected by gas chromatography at the outlet of the reaction tube. The content of CHF3 in the obtained gaseous products was 1 volume.

[0333] After 9 hours of reaction, the solid material in the reaction tube was removed, and its surface elemental content was analyzed by X-ray photoelectron spectroscopy (XPS). The results showed that the F content was 0.18% (mass fraction)% and the Al content was 7.44% (mass fraction)%. The F content was very low, and the F spectrum signal was weak.

[0334] In addition, observation revealed that the surface of the solid material was grayish-black with obvious carbon deposits.

[0335] The results showed that in the presence of hydrogen chloride, the reaction degree between aluminum metaphosphate and CHF3 was low, making it difficult to remove CHF3 and preventing the production of aluminum fluoride.

[0336] Comparative Example 3

[0337] The procedure is carried out according to the method described in Example 1, except that...

[0338] Replace the metal compound γ-alumina with an equal weight of copper aluminate.

[0339] After 1 hour of reaction, the gaseous products of the reaction were detected by gas chromatography at the outlet of the reaction tube. The content of CHF3 in the obtained gaseous products was 1 volume.

[0340] After 9 hours of reaction, the solid material in the reaction tube was removed, and its surface elemental content was analyzed by X-ray photoelectron spectroscopy (XPS). The results showed that the F content was 0.02% (mass fraction)% and the Al content was 37.04% (mass fraction)%. The F content was very low, and the F spectrum signal was weak.

[0341] In addition, observation revealed that the surface of the solid material was distinctly black, with obvious carbon buildup.

[0342] The results showed that copper aluminate reacted with CHF3 to a low degree, making it difficult to remove CHF3 and unable to produce aluminum fluoride.

[0343] Application Example 1

[0344] 1) 0.1257 L (90.23 g) of γ-alumina (a metallic compound) with a particle size of 2-3 mm was packed into a reaction tube. The temperature was raised to the reaction temperature of 370 °C. At this temperature, a mixed gas of CHF3, CHClF, and HCl was continuously introduced, with CHF3 concentration at 0.16 vol%, CHClF concentration at 0.08 vol%, and the remainder being hydrogen chloride. The inlet volume hourly space velocity (VHSV) of the mixed gas was 240 h⁻¹. -1 The product with the removed organic fluorine was obtained from the gas outlet of the reaction tube;

[0345] 2) The organic fluorine-free product obtained in step 1) is sequentially passed through an HF adsorption tower (specifically, SCAF-20 hydrogen fluoride adsorbent produced by Sinopec Catalyst Co., Ltd.) and a carbon monoxide removal reactor (specifically, SCCC-10 carbon monoxide treatment catalyst produced by Sinopec Catalyst Co., Ltd.) to obtain defluorinated feed gas.

[0346] 3) The defluorination feed gas obtained in step 2) (calculated based on the molar amount of hydrogen chloride) and oxygen are introduced into a fixed-bed reactor packed with a catalyst for the catalytic oxidation of hydrogen chloride to chlorine at a molar ratio of 1:0.5. The reaction temperature is 370℃, the reaction pressure is 0.1MPa, and the inlet volume hourly space velocity of the mixed gas feed gas (the mixture of defluorination feed gas and oxygen) is 293h⁻¹. -1 After a continuous reaction of 360 hours, the conversion rate of HCl was measured to be 90%.

[0347] After the reaction was stopped and the catalyst was removed, no carbon deposits were found on the catalyst surface.

[0348] Comparative Application Example 1

[0349] The method is the same as in Example 1, except that...

[0350] Skip step 1), directly heat the raw gas to 370°C, and then proceed with subsequent steps 2) and 3) according to the method in Application Example 1.

[0351] After 6 hours of continuous reaction, the conversion rate of HCl was measured to be 80%. After 24 hours of continuous reaction, the conversion rate of HCl was 50%.

[0352] After the reaction was stopped and the catalyst was removed, obvious carbon deposits were found on the catalyst surface.

[0353] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method of treating a fluorine-containing organic substance, characterized by, The method comprises: contacting a fluorine-containing organic compound with a metal compound in the presence of hydrogen chloride to produce a metal fluoride, wherein the metal compound has L acid in the presence of hydrogen chloride.

2. A method of purifying hydrogen chloride gas containing fluorine-containing organic matter, characterized by, The method comprises: contacting a hydrogen chloride gas containing a fluorine-containing organic compound with a metal compound to remove the fluorine-containing organic compound in the hydrogen chloride gas and produce a metal fluoride, wherein the metal compound has L acid in the presence of hydrogen chloride.

3. The method of claim 1 or 2, wherein, The fluorine-containing organic compound is a fluorine-containing hydrocarbon with a carbon atom number of 1-8, more preferably a fluorine-containing hydrocarbon with a carbon atom number of 1-4, and further preferably a fluorine-containing hydrocarbon with a carbon atom number of 1-2; Preferably, the fluorine-containing organic compound is represented by the following formula (1) or formula (2): C n H x F y Cl z Formula (1); C m H o F p Cl q Formula (2); In formula (1), n is an integer of 1-8, preferably 1-4, and more preferably 1 or 2; x and z are each an integer of 0 or more, y is an integer of 1 or more, and x+y+z=2n+2, In formula (2), m is an integer of 2-8, preferably 2-4, and more preferably 2; o and q are each an integer of 0 or more, p is an integer of 1 or more, and o+p+q=2n, Preferably, the fluorine-containing organic compound is one or more of monofluoromethane, difluoromethane, trifluoromethane, difluoro-chloromethane, difluoroethane, trifluoroethane, tetrafluoroethane, pentafluoroethane, difluoro-chloroethane, pentafluoro-chloroethane, difluoroethylene, tetrafluoroethylene, and trifluoro-chloroethylene; More preferably, the fluorine-containing organic compound is one or more of trifluoromethane, pentafluoroethane, difluoroethylene, and difluoro-chloromethane.

4. The method of any of claims 1-3, wherein, The metal compound is one or more of an oxide, a hydroxide, a chloride, and a oxychloride of a metal; Preferably, the metal in the metal compound is selected from one or more of aluminum, gallium, tin, iron, vanadium, chromium, zirconium, niobium, antimony, zinc, cobalt, nickel, and indium, and more preferably aluminum and / or zirconium; Preferably, the metal compound is one or more of aluminum oxide, aluminum hydroxide, hydrated aluminum hydroxide, aluminum chloride, aluminum oxychloride, zirconium oxide, zirconium oxychloride, and zirconium hydroxide; More preferably, the metal compound is one or more of aluminum oxide, aluminum oxychloride, aluminum hydroxide, zirconium oxychloride, and zirconium oxide; Preferably, the particle size of the metal compound is 0.001-5 mm; More preferably, the particle size of the metal compound is 0.001-0.2 mm; or More preferably, the particle size of the metal compound is 0.1-5 mm.

5. The method of any of claims 1-4, wherein, The conditions of the contact include: temperature of 50-750℃, volume space velocity of the mixed gas of the fluorine-containing organic matter and hydrogen chloride of 1-10000h -1 ; Preferably, the conditions of the contacting include: a temperature of 300-500°C, a volume hourly space velocity of the mixed gas of the fluorine-containing organic matter and hydrogen chloride of 50-1000h -1 ; Preferably, the contacting is performed in the absence of water vapor; Preferably, the contacting is performed in the absence of oxygen.

6. The method of claim 2, wherein, The hydrogen chloride gas containing the fluorine-containing organic compound further contains hydrogen fluoride; Preferably, in the hydrogen chloride gas containing the fluorine-containing organic compound, the content of hydrogen chloride is 90-99.9% by volume, the content of the fluorine-containing organic compound is 0.1-10% by volume, and the content of hydrogen fluoride is 0-1% by volume; More preferably, in the hydrogen chloride gas containing the fluorine-containing organic compound, the content of hydrogen chloride is 95-99.9% by volume, the content of the fluorine-containing organic compound is 0.1-5% by volume, and the content of hydrogen fluoride is 0-1% by volume; Preferably, the hydrogen chloride gas containing the fluorine-containing organic compound further contains sulfur hexafluoride and / or sulfur tetrafluoride.

7. A method of producing chlorine, characterized by, Preparation of chlorine gas from hydrogen chloride gas containing fluorine-containing organic matter, the method comprising the following steps: 1) first contact the raw material with a metal compound to obtain a defluorinated raw material; 2) second contact the defluorinated raw material obtained in step 1) with oxygen in the presence of a catalyst, wherein the metal compound contains L acid under the action of hydrogen chloride, and the catalyst is a hydrogen chloride catalytic oxidation catalyst for preparing chlorine gas.

8. The production method according to claim 7, wherein The fluorine-containing organic matter is a fluorine-containing hydrocarbon with a carbon atom number of 1-8, more preferably a fluorine-containing hydrocarbon with a carbon atom number of 1-4, and further preferably a fluorine-containing hydrocarbon with a carbon atom number of 1-2; Preferably, the fluorine-containing organic matter is represented by the following formula (1) or formula (2): C n H x F y Cl z Formula (1); C m H o F p Cl q Formula (2); In formula (1), n is an integer of 1-8, preferably 1-4, and more preferably 1 or 2; x and z are both integers of 0 or more, y is an integer of 1 or more, and x+y+z=2n+2, In formula (2), m is an integer of 2-8, preferably 2-4, and more preferably 2; o and q are both integers of 0 or more, p is an integer of 1 or more, and o+p+q=2n, Preferably, the fluorine-containing organic matter is one or more of monofluoromethane, difluoromethane, trifluoromethane, difluoro-monochloromethane, difluoroethane, trifluoroethane, tetrafluoroethane, pentafluoroethane, difluoro-monochloroethane, pentafluoro-monochloroethane, difluoroethylene, tetrafluoroethylene, and trifluoro-chloroethylene; More preferably, the fluorine-containing organic matter is one or more of trifluoromethane, pentafluoroethane, difluoroethylene, and difluoro-monochloromethane; Preferably, in the hydrogen chloride gas containing fluorine-containing organic matter, the content of fluorine-containing organic matter is 0.0001-10% by volume, more preferably 0.1-5% by volume, and further preferably 0.5-3% by volume.

9. The production method according to claim 7 or 8, wherein The metal compound is one or more of oxides, hydroxides, chlorides, and oxychlorides of metals; Preferably, the metal in the metal compound is selected from one or more of aluminum, gallium, tin, iron, vanadium, chromium, zirconium, niobium, antimony, zinc, cobalt, nickel, and indium, and more preferably aluminum and / or zirconium; Preferably, the metal compound is one or more of aluminum oxide, aluminum hydroxide, aluminum chloride, hydrated aluminum hydroxide, aluminum oxychloride, zirconium oxide, zirconium oxychloride, and zirconium hydroxide; More preferably, the metal compound is one or more of aluminum oxide, aluminum oxychloride, aluminum hydroxide, zirconium oxychloride, and zirconium oxide; Preferably, the particle size of the metal compound is 0.001-5mm; More preferably, the particle size of the metal compound is 0.001-0.2mm; or More preferably, the particle size of the metal compound is 0.1-5mm.

10. The method of manufacturing according to any one of claims 7-9, wherein, In step 1), the conditions of the first contacting include a temperature of 50-750°C, a volume hourly space velocity of the raw material of 1-10,000 h -1 ; Preferably, the conditions of said first contacting comprise a temperature of 360-460°C and a volume hourly space velocity of the feedstock of 50-1000 h -1 ; Preferably, the first contact is carried out under conditions free of water vapor; Preferably, the first contact is carried out under conditions free of oxygen; Preferably, in step 2), the conditions of the second contact include: a temperature of 280-420°C; and a molar ratio of hydrogen chloride in the defluorinated raw material to oxygen of 0.25-10:1; More preferably, the conditions of the second contact include: a temperature of 320-390°C, and a molar ratio of hydrogen chloride in the defluorinated raw material to oxygen of 0.5-4:1; Preferably, the temperature of the first contact is 0-180℃ higher than the temperature of the second contact.

11. The method of manufacturing according to any one of claims 7-10, wherein, Step 1) further comprises: a step of treating the gas product obtained from the first contact to remove HF; and / or a step of treating the gas product obtained after the first contact to remove CO.

12. A method of producing a metal fluoride, characterized by, The preparation method comprises: contacting a fluorine-containing organic compound with a metal compound in the presence of hydrogen chloride, wherein the metal compound in the presence of hydrogen chloride exists L acid.

13. The production method according to claim 12, wherein The fluorine-containing organic compound is a fluorine-containing hydrocarbon with a carbon atom number of 1-8, more preferably a fluorine-containing hydrocarbon with a carbon atom number of 1-4, and further preferably a fluorine-containing hydrocarbon with a carbon atom number of 1-2; Preferably, the fluorine-containing organic compound is represented by the following formula (1) or formula (2): C n H x F y Cl z Formula (1); C m H o F p Cl q Formula (2); In formula (1), n is an integer of 1-8, preferably 1-4, and more preferably 1 or 2; x and z are both integers of 0 or more, y is an integer of 1 or more, and x+y+z=2n+2, In formula (2), m is an integer of 2-8, preferably 2-4, and more preferably 2; o and q are both integers of 0 or more, p is an integer of 1 or more, and o+p+q=2n, Preferably, the fluorine-containing organic compound is one or more of monofluoromethane, difluoromethane, trifluoromethane, difluoro-chloromethane, difluoroethane, trifluoroethane, tetrafluoroethane, pentafluoroethane, difluoro-chloroethane, pentafluoro-chloroethane, difluoroethylene, tetrafluoroethylene and trifluoro-chloroethylene; More preferably, the fluorine-containing organic compound is one or more of trifluoromethane, pentafluoroethane, difluoroethylene and difluoro-chloromethane.

14. The production method according to claim 12 or 13, wherein The metal compound is one or more of oxides, hydroxides, chlorides and oxychlorides of a metal, the metal in the metal compound is selected from one or more of aluminum, gallium, tin, iron, vanadium, chromium, zirconium, niobium, antimony, zinc, cobalt, nickel and indium, and preferably aluminum and / or zirconium; Preferably, the metal compound is one or more of aluminum oxide, aluminum hydroxide, aluminum chloride, aluminum oxychloride, zirconium oxide, zirconium oxychloride and zirconium hydroxide; More preferably, the metal compound is one or more of aluminum oxide, aluminum oxychloride, aluminum hydroxide, zirconium oxychloride and zirconium oxide; Further preferably, the metal compound is one or more of aluminum oxide, aluminum oxychloride and aluminum hydroxide, and the metal fluoride is aluminum fluoride; Preferably, the particle size of the metal compound is 0.001-5mm; More preferably, the particle size of the metal compound is 0.001-0.2mm, or, More preferably, the particle size of the metal compound is 0.1-5mm.

15. The preparation method according to any one of claims 12-14, wherein, The conditions of the contact include a temperature of 50 to 750°C and a volume space velocity of the mixed gas of the fluorine-containing organic compound and hydrogen chloride of 1 to 10,000 h -1 -1; more preferably, the conditions of the contact include a temperature of 350 to 500°C and a volume space velocity of the mixed gas of the fluorine-containing organic compound and hydrogen chloride of 50 to 1,000 h -1 -1. Preferably, the contacting is carried out in the absence of water vapor; Preferably, the contacting is carried out in the absence of oxygen.

16. The method of making according to any one of claims 12-15, wherein, The method comprises: contacting a fluorine-containing organic compound with one or more of aluminum oxide, aluminum hydroxide, aluminum oxychloride and aluminum chloride in the presence of hydrogen chloride to prepare aluminum fluoride; Preferably, the method comprises: contacting a mixture of a fluorine-containing organic compound and hydrogen chloride with one or more of aluminum oxide, aluminum hydroxide and aluminum oxychloride to prepare aluminum fluoride.

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