Method for treating fluorine-containing organic matter, method for purifying hydrogen chloride gas, method for preparing metal fluoride, and method for preparing chlorine gas

Abstract

The present invention relates to the field of fluorine-containing organic matter treatment, and specifically relates to a method for treating a fluorine-containing organic matter, a method for purifying hydrogen chloride gas, a method for preparing a metal fluoride, and a method for preparing chlorine gas from hydrogen chloride gas. The method for treating a fluorine-containing organic matter comprises: in the presence of hydrogen chloride, bringing a fluorine-containing organic matter into contact with a metal compound to generate a metal fluoride, wherein an L acid is present in the metal compound under the action of hydrogen chloride. Therefore, the method can not only effectively remove a fluorine-containing organic matter, such that hydrogen chloride gas is purified, but can also be used for the preparation of chlorine gas; in addition, the fluorine-containing organic matter can be further converted into a metal fluoride having a high added value, such as aluminum fluoride.

Description

Method for treating fluorine-containing organic matter, method for purifying hydrogen chloride gas, method for preparing metal fluoride, and method for preparing chlorine gas

[0001] Cross-reference to Related Applications

[0002] This application claims the benefit of Chinese Patent Application No. 202410891336.5, filed July 4, 2024, and Chinese Patent Application No. 202411179435.7, filed August 27, 2024, the contents of which are incorporated herein by reference. TECHNICAL FIELD

[0003] The present application relates to the field of fluorine-containing organic matter treatment, in particular to a method for treating fluorine-containing organic matter, a method for purifying hydrogen chloride gas, a method for preparing metal fluoride, and a method for preparing chlorine gas from hydrogen chloride gas. BACKGROUND

[0004] Organic fluorination is an important branch of fluorination industry, mainly involving fluorine-containing polymers, fluorine-containing fine chemicals, fluorocarbons and other fluorine-containing organic matters, which are widely used in the fields of electrical appliances, medicine, chips, transportation, new energy, environmental protection industry, etc., and the market size of the organic fluorination industry has been growing continuously in recent years.

[0005] In the production process of organic fluorination, organic matter is first chlorinated with chlorine to generate organic chlorides, and then hydrogen fluoride is reacted with the organic chlorides to obtain the corresponding fluorine-containing organic matter. In this process, a large amount of by-product hydrogen chloride is generated, and a small amount of fluorine-containing organic matter, hydrogen fluoride and other substances are often present in the obtained by-product hydrogen chloride. Depending on the different fluorination processes, the types of fluorine-containing organic matter may include, for example, CHF3, CHClF2, CF3CF2Cl, CH3CF3, CH2FCF3, etc. The yield of by-product hydrogen chloride in such organic fluorination is large, and if it cannot be reasonably recycled, a large amount of fluorine-containing hazardous waste hydrochloric acid will be generated, which is not only difficult to effectively treat, but also will cause great harm to the environment.

[0006] 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 also expanding year by year.

[0007] Hydrogen chloride catalytic oxidation to prepare chlorine gas is one of the current industrial methods for preparing chlorine gas, and if the by-product hydrogen chloride from the above-mentioned organic fluorination can be used to prepare chlorine gas, not only the problem of its disposal can be solved, but also the recycling of chlorine resources can be realized, which produces important economic value and social benefits.

[0008] To this end, the inventors of the present application attempted to use the above-mentioned by-product hydrogen chloride to prepare chlorine. However, it was found in the course of experiments that, when using the by-product hydrogen chloride as raw material to prepare chlorine by the method of the prior art, the reaction activity of the catalyst for the catalytic oxidation of hydrogen chloride to prepare chlorine would rapidly decrease in a short time with the introduction of the by-product hydrogen chloride, resulting in that the reaction system could not be stably operated for a long period of time, and it was difficult to realize the industrial production of chlorine.

[0009] Further in-depth research by the inventors found that the reason why the above production could not be smoothly carried out was that the fluorine-containing organic compounds present in the by-product hydrogen chloride would poison the catalyst for the catalytic oxidation of hydrogen chloride to prepare chlorine, causing the catalyst to be deactivated, and thus the preparation of chlorine could not be smoothly realized.

[0010] In order to overcome the above-mentioned problems found in the research and development process, the inventors tried to eliminate the influence of the fluorine-containing organic compounds in the by-product hydrogen chloride on the preparation of chlorine by using various methods.

[0011] For example, the inventors tried to remove the fluorine-containing organic compounds in the by-product hydrogen chloride by water absorption-desorption. It was found through a large number of experiments that this method could reduce the content of fluorine-containing organic compounds to a certain extent (for example, the content of fluorine-containing organic compounds could be reduced from 1-5% by volume to about 0.5% by volume), but it could not completely remove the fluorine-containing organic compounds, and it was further found through further tests that the low content of fluorine-containing organic compounds remaining in the by-product hydrogen chloride after desorption treatment would still have a significant impact on the catalyst for the catalytic oxidation of hydrogen chloride to prepare chlorine, resulting in that the production of chlorine could not be carried out stably for a long period of time. In addition, this method has high energy consumption and complex operation, which will significantly increase the production burden and is not suitable for industrial production.

[0012] For another example, the inventors explored the use of adsorbents to selectively adsorb the fluorine-containing organic compounds in the by-product hydrogen chloride. Specifically, resin, activated carbon, molecular sieve, MOF material and the like were used for adsorption treatment experiments. It was found that although the fluorine-containing organic compounds in the air could be more easily adsorbed by some adsorbents, the fluorine-containing organic compounds in the hydrogen chloride were difficult to be effectively adsorbed. The reason may be that the content of hydrogen chloride in the by-product hydrogen chloride is often high (more than 90% by volume), and the properties of hydrogen chloride are close to those of some fluorine-containing organic compounds (for example, hydrogen chloride and trifluoromethane are both polar substances, and their boiling points are very close). Therefore, the presence of hydrogen chloride will cause strong adsorption competition for the adsorption of fluorine-containing organic compounds, resulting in poor separation effect of selective adsorption, and it is difficult to economically and efficiently separate hydrogen chloride and fluorine-containing organic compounds. In addition, the above-mentioned MOF material can exhibit good adsorption performance for fluorine-containing organic compounds, but its price is high, and it is difficult to realize large-scale industrial production.

[0013] On the other hand, the industry generally adopts the way of catalytic oxidation and catalytic hydrolysis to convert fluorine-containing organic matter. For example, CN117732241A discloses a method for effectively decomposing fluorine-containing alkane substances, which adopts a catalyst to catalytically oxidize and catalytically hydrolyze fluorine-containing waste gas. However, the catalysts for catalytic oxidation and catalytic hydrolysis generally adopt solid acid catalysts, which have strong surface acidity and are easy to be carbonized and deactivated, and have poor stability, so it is difficult to simultaneously consider good activity and stability. In addition, sulfates can also be used as such catalysts, but sulfates have low acidity, poor conversion ability for general raw materials, and are easy to be destroyed by HF generated in the reaction, so they have poor stability. In addition, the high content of hydrogen chloride in the by-product hydrogen chloride makes it more difficult for the fluorine-containing organic matter catalytic oxidation and catalytic hydrolysis catalysts in the prior art to effectively treat fluorine-containing organic matter under high hydrogen chloride content.

[0014] In summary, due to the complexity and particularity of the by-product hydrogen chloride in organic fluorine chemical industry, it is currently impossible to realize the industrial production of chlorine gas by using the by-product hydrogen chloride as raw material.

[0015] If a suitable method can be found to remove the fluorine-containing organic matter in the by-product hydrogen chloride, and the by-product hydrogen chloride in the organic fluorine chemical industry is used to realize the industrial production of chlorine gas, the problem of treating the by-product hydrogen chloride in the organic fluorine chemical industry will be solved, the recycling of resources will be realized, and the economic benefits of the industrial chain will be greatly improved. SUMMARY

[0016] The purpose of the present application is to overcome the problems in the prior art, such as the difficulty in removing fluorine-containing organic matter in hydrogen chloride gas, and the difficulty in using hydrogen chloride containing fluorine-containing organic matter to prepare chlorine gas, and to provide a treatment method for fluorine-containing organic matter, a purification method for hydrogen chloride gas, a preparation method for metal fluoride, and a preparation method for chlorine gas, and to provide a method for co-producing metal fluoride by purifying hydrogen chloride gas and a method for co-producing metal fluoride by preparing chlorine gas from hydrogen chloride gas.

[0017] The method provided by the present application not only can effectively remove fluorine-containing organic matter in the presence of hydrogen chloride, or purify hydrogen chloride gas containing fluorine-containing organic matter, and then be used for the preparation of chlorine gas, but also can convert the fluorine-containing organic matter in the hydrogen chloride gas into metal fluoride products such as aluminum fluoride with high added value. Thus, not only the problem of treating the by-product hydrogen chloride in the organic fluorine chemical industry is solved, but also the production of chlorine gas can be realized by using the by-product hydrogen chloride as raw material, and high-quality metal fluoride products can also be prepared. In addition, the entire reaction route not only removes the fluorine-containing organic matter, but also converts the metal compounds with low economic value into metal fluoride products, and does not produce new industrial waste, which produces great economic benefits.

[0018] As described above, the inventors of the present application found that, in the presence of hydrogen chloride gas, the reaction of hydrogen chloride gas to produce chlorine gas can be carried out stably for a long period of time under the action of a chlorine gas production catalyst and oxygen gas, whereas when hydrogen chloride containing a fluorine-containing organic compound is used to produce chlorine gas, the activity of the catalyst rapidly decreases in a short period of time, and carbon deposition is observed on the surface of the catalyst bed.

[0019] As a result of extensive research and experiments, the inventors of the present application found that, in the presence of hydrogen chloride, a specific metal compound can react with a fluorine-containing organic compound and be converted into a metal fluoride, and the reaction can be carried out stably for a long period of time under the condition that the reactants are sufficient. Although the mechanism thereof has not been fully understood, it is presumed that the specific metal compound has L acid in the presence of hydrogen chloride, which can initiate the reaction of the fluorine-containing organic compound with the metal compound and suppress the carbon deposition on the surface of the metal compound, thereby enabling the reaction to be carried out stably until the metal compound is completely fluorinated or the fluorine-containing organic compound is completely reacted, thereby completing the present application.

[0020] The present application provides, in a first aspect, a method for treating a fluorine-containing organic compound, wherein the method comprises:

[0021] contacting the fluorine-containing organic compound with a metal compound in the presence of hydrogen chloride to produce a metal fluoride,

[0022] wherein the metal compound has L acid in the presence of hydrogen chloride.

[0023] Preferably, the fluorine-containing organic compound is a fluorine-containing hydrocarbon having 1 to 8 carbon atoms, more preferably a fluorine-containing hydrocarbon having 1 to 4 carbon atoms, and further preferably a fluorine-containing hydrocarbon having 1 to 3 carbon atoms.

[0024] Preferably, the fluorine-containing organic compound includes one or more of a fluorine-containing hydrocarbon represented by the following formula (1) or formula (2): n H x F y Cl z Formula (1); C m H o F p Cl q Formula (2);

[0025] In formula (1), n is an integer selected from 1 to 8, preferably from 1 to 3;

[0026] x and z are each independently an integer of 0 or more, y is an integer of 1 or more, and x + y + z = 2n + 2,

[0027] In formula (2), m is an integer selected from 2 to 8, preferably from 2 to 3;

[0028] o, q are each independently selected from an integer of 0 or above, p is selected from an integer of 1 or above, and o + p + q = 2m, or o + p + q = 2m - 2.

[0029] Preferably, the fluorine-containing organic matter is one or more of monofluoromethane, difluoromethane, trifluoromethane, difluoro-chloromethane, monofluoro-dichloromethane, monofluoro-dichloroethane, difluoroethane, trifluoroethane, tetrafluoroethane, pentafluoroethane, difluoro-chloroethane, pentafluoro-chloroethane, difluoroethylene, tetrafluoroethylene, trifluoro-chloroethylene and hexafluoropropylene.

[0030] More preferably, the fluorine-containing organic matter is one or more of trifluoromethane, difluoro-chloromethane, monofluoro-dichloromethane, pentafluoro-chloroethane, difluoroethylene and hexafluoropropylene.

[0031] Preferably, the metal compound is one or more of oxide, hydroxide, chloride and oxychloride of the metal; more preferably, oxide and / or hydroxide of the metal.

[0032] 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, one or more of aluminum, zirconium and chromium.

[0033] Preferably, the metal compound is one or more of aluminum oxide, aluminum hydroxide, zirconium oxide and chromium oxide.

[0034] 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.

[0035] Preferably, the contacting is carried out under the conditions of temperature of 50-750℃ and volume space velocity of the mixed gas of the fluorine-containing organic matter and hydrogen chloride of 1-10000h -1 ; more preferably, the contacting is carried out under the conditions of temperature of 350-500℃ and volume space velocity of the mixed gas of the fluorine-containing organic matter and hydrogen chloride of 50-1000h -1 .

[0036] Preferably, the contacting is carried out without adding water vapor. Preferably, the contacting is carried out without adding oxygen.

[0037] The second aspect of the present application provides a method for purifying hydrogen chloride gas, wherein the hydrogen chloride gas contains fluorine-containing organic matter, the method comprising: contacting the hydrogen chloride gas with a metal compound to obtain fluorine-removed hydrogen chloride gas and generate metal fluoride, wherein the metal compound has L acid under the action of hydrogen chloride.

[0038] Preferably, the fluorine-containing organic substance is a fluorine-containing hydrocarbon having 1 to 8 carbon atoms, more preferably a fluorine-containing hydrocarbon having 1 to 4 carbon atoms, further preferably a fluorine-containing hydrocarbon having 1 to 3 carbon atoms.

[0039] Preferably, the fluorine-containing organic substance includes one or more of fluorine-containing hydrocarbons represented by the following formula (1) or formula (2): n H x F y Cl z Formula (1); C m H o F p Cl q Formula (2);

[0040] In formula (1), n is selected from an integer of 1 to 8, preferably from 1 to 3;

[0041] x, z are each independently selected from an integer of 0 or more, y is selected from an integer of 1 or more, and x + y + z = 2n + 2,

[0042] In formula (2), m is selected from an integer of 2 to 8, preferably from 2 to 3;

[0043] o, q are each independently selected from an integer of 0 or more, p is selected from an integer of 1 or more, and o + p + q = 2m, or o + p + q = 2m - 2.

[0044] Preferably, the fluorine-containing organic substance is one or more of monofluoromethane, difluoromethane, trifluoromethane, difluoro-chloromethane, monofluoro-dichloromethane, monofluoro-dichloroethane, difluoroethane, trifluoroethane, tetrafluoroethane, pentafluoroethane, difluoro-chloroethane, pentafluoro-chloroethane, difluoroethylene, tetrafluoroethylene, trifluoro-chloroethylene, and hexafluoropropylene.

[0045] More preferably, the fluorine-containing organic substance is one or more of trifluoromethane, difluoro-chloromethane, monofluoro-dichloromethane, pentafluoro-chloroethane, difluoroethylene, and hexafluoropropylene.

[0046] Preferably, the metal compound is one or more of an oxide, a hydroxide, a chloride, and an oxychloride of a metal; more preferably an oxide and / or a hydroxide of a metal.

[0047] 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 one or more of aluminum, zirconium, and chromium.

[0048] Preferably, the metal compound is one or more of aluminum oxide, aluminum hydroxide, zirconium oxide, and chromium oxide.

[0049] 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.

[0050] Preferably, the contacting is carried out at a temperature of 50-750℃ and a volume space velocity of the mixed gas of the fluorine-containing organic compound and hydrogen chloride of 1-10000 h -1 ; more preferably, the contacting is carried out at a temperature of 350-500℃ and a volume space velocity of the mixed gas of the fluorine-containing organic compound and hydrogen chloride of 50-1000 h -1 .

[0051] Preferably, the contacting is carried out without adding water vapor.

[0052] Preferably, the contacting is carried out without adding oxygen.

[0053] Preferably, the content of hydrogen chloride in the hydrogen chloride gas is 50% by volume or more, preferably 90% by volume or more, and more preferably 95% by volume or more.

[0054] Preferably, the content of the fluorine-containing organic compound in the hydrogen chloride gas is 5% by volume or less.

[0055] Preferably, the hydrogen chloride gas further contains hydrogen fluoride, and the content of hydrogen fluoride is preferably 1% by volume or less.

[0056] Preferably, the hydrogen chloride gas further contains sulfur hexafluoride and / or sulfur tetrafluoride.

[0057] Preferably, the method is such that the content of the fluorine-containing organic compound in the defluorinated hydrogen chloride gas is 500 ppm or less, more preferably 100 ppm or less, and further preferably 1 ppm or less.

[0058] The third aspect of the present application provides a method for producing a metal fluoride, wherein 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 exists in the form of L acid under the action of hydrogen chloride.

[0059] Preferably, the fluorine-containing organic compound is a fluorine-containing hydrocarbon having 1-8 carbon atoms, more preferably a fluorine-containing hydrocarbon having 1-4 carbon atoms, and further preferably a fluorine-containing hydrocarbon having 1-3 carbon atoms.

[0060] Preferably, the fluorine-containing organic compound includes one or more of fluorine-containing hydrocarbons represented by the following formula (1) or formula (2): C n H x F y Cl zFormula (1); C m H o F p Cl q Formula (2);

[0061] In Formula (1), n is an integer selected from 1-8, preferably from 1-3;

[0062] x, z are each independently an integer of 0 or more, y is an integer of 1 or more, and x+y+z=2n+2,

[0063] In Formula (2), m is an integer selected from 2-8, preferably from 2-3;

[0064] o, q are each independently an integer of 0 or more, p is an integer of 1 or more, and o+p+q=2m, or o+p+q=2m-2.

[0065] Preferably, the fluorine-containing organic compound is one or more of monofluoromethane, difluoromethane, trifluoromethane, difluoro-chloromethane, monofluoro-dichloromethane, monofluoro-dichloroethane, difluoroethane, trifluoroethane, tetrafluoroethane, pentafluoroethane, difluoro-chloroethane, pentafluoro-chloroethane, difluoroethylene, tetrafluoroethylene, trifluoro-chloroethylene, and hexafluoropropylene.

[0066] More preferably, the fluorine-containing organic compound is one or more of trifluoromethane, difluoro-chloromethane, monofluoro-dichloromethane, pentafluoro-chloroethane, difluoroethylene, and hexafluoropropylene.

[0067] Preferably, the metal compound is one or more of an oxide, a hydroxide, a chloride, and an oxychloride of a metal; more preferably, an oxide and / or a hydroxide of a metal.

[0068] 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, one or more of aluminum, zirconium, and chromium.

[0069] Preferably, the metal compound is one or more of aluminum oxide, aluminum hydroxide, zirconium oxide, and chromium oxide.

[0070] 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,

[0071] or, more preferably, the particle size of the metal compound is 0.1-5 mm.

[0072] Preferably, the conditions of the contacting include: a temperature of 50-750°C, a volume hourly space velocity of the mixed gas of the fluorine-containing organic compound and hydrogen chloride of 1-10000 h -1; more preferably, the conditions of the contacting include: temperature of 350-500°C, volume hourly space velocity of the mixed gas of the fluorine-containing organic matter and hydrogen chloride of 50-1000h -1 .

[0073] Preferably, the contacting is carried out without adding water vapor.

[0074] Preferably, the contacting is carried out without adding oxygen.

[0075] Preferably, the contacting is such that the molar ratio of fluorine atoms to metal atoms in the generated metal fluoride is 90% or more, more preferably 95% or more, of the theoretical atomic molar ratio of the two.

[0076] Preferably, the method includes: contacting the fluorine-containing organic matter with aluminum oxide and / or aluminum hydroxide in the presence of hydrogen chloride to prepare aluminum fluoride.

[0077] Alternatively, the method includes: contacting a mixture of the fluorine-containing organic matter and hydrogen chloride with aluminum oxide and / or aluminum hydroxide to prepare aluminum fluoride.

[0078] The fourth aspect of the present application provides a method for preparing chlorine gas from hydrogen chloride gas, wherein the hydrogen chloride gas contains a fluorine-containing organic matter, and the method includes:

[0079] 1) first contacting the hydrogen chloride gas with a metal compound to obtain a defluorinated hydrogen chloride gas and generate a metal fluoride;

[0080] 2) second contacting the defluorinated hydrogen chloride gas obtained in step 1) with oxygen in the presence of a catalyst,

[0081] 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.

[0082] Preferably, 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 1-3.

[0083] Preferably, the fluorine-containing organic matter includes one or more of the fluorine-containing hydrocarbons represented by the following formula (1) or formula (2): n H x F y Cl z Formula (1); C m H o F p Cl q Formula (2);

[0084] In formula (1), n is selected from an integer of 1-8, preferably 1-3.

[0085] x, z are each independently selected from an integer of 0 or above, y is selected from an integer of 1 or above, and x + y + z = 2n + 2,

[0086] In formula (2), m is selected from an integer of 2-8, preferably from 2-3;

[0087] o, q are each independently selected from an integer of 0 or above, p is selected from an integer of 1 or above, and o + p + q = 2m, or o + p + q = 2m - 2.

[0088] Preferably, the fluorine-containing organic compound is one or more of monofluoromethane, difluoromethane, trifluoromethane, difluoro-chloromethane, monofluoro-dichloromethane, monofluoro-dichloroethane, difluoroethane, trifluoroethane, tetrafluoroethane, pentafluoroethane, difluoro-chloroethane, pentafluoro-chloroethane, difluoroethylene, tetrafluoroethylene, trifluoro-chloroethylene, and hexafluoropropylene.

[0089] More preferably, the fluorine-containing organic compound is one or more of trifluoromethane, difluoro-chloromethane, monofluoro-dichloromethane, pentafluoro-chloroethane, difluoroethylene, and hexafluoropropylene.

[0090] Preferably, the content of the fluorine-containing organic compound in the hydrogen chloride gas is 10 vol% or less, more preferably 5 vol% or less.

[0091] Preferably, the metal compound is one or more of an oxide, a hydroxide, a chloride, and an oxychloride of a metal; more preferably, an oxide and / or a hydroxide of a metal.

[0092] 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, one or more of aluminum, zirconium, and chromium.

[0093] Preferably, the metal compound is one or more of aluminum oxide, aluminum hydroxide, zirconium oxide, and chromium oxide.

[0094] 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.

[0095] Preferably, in step 1), the first contacting is such that the content of the fluorine-containing organic compound in the obtained defluorinated hydrogen chloride gas is 500 ppm or less, more preferably 100 ppm or less.

[0096] Preferably, in step 1), the first contacting is under conditions including: a temperature of 50-750°C, a volume hourly space velocity of the raw material of 1-10000 h -1; more preferably, the conditions of the first contact include: the temperature is 360-460℃, the volume space velocity of the hydrogen chloride gas is 50-1000h -1 .

[0097] Preferably, the first contact is carried out without adding water vapor.

[0098] Preferably, the first contact is carried out without adding oxygen.

[0099] Preferably, in step 2), the conditions of the second contact include: the temperature is 280-420℃; the molar ratio of hydrogen chloride to oxygen in the defluorinated hydrogen chloride gas is 0.25-10:1; more preferably, the conditions of the second contact include: the temperature is 320-390℃, the molar ratio of hydrogen chloride to oxygen in the defluorinated hydrogen chloride gas is 0.5-4:1.

[0100] Preferably, the temperature of the first contact is 0-180℃ higher than the temperature of the second contact.

[0101] Preferably, step 1) further comprises: a step of subjecting the gaseous product obtained after the first contact to a HF removal treatment to obtain a defluorinated hydrogen chloride gas; and / or a step of subjecting the gaseous product obtained after the first contact to a CO removal treatment to obtain a defluorinated hydrogen chloride gas.

[0102] The fifth aspect of the present application provides a method for purifying hydrogen chloride gas and co-producing metal fluoride, wherein the hydrogen chloride gas contains fluorine-containing organic matter, and the method comprises:

[0103] 1) subjecting the hydrogen chloride gas to a first reaction by passing through one or more reaction units filled with metal compounds to obtain a defluorinated hydrogen chloride gas, and allowing part of the metal compounds to generate metal fluoride,

[0104] wherein the metal compound, under the action of hydrogen chloride, contains L acid;

[0105] The content of fluorine-containing organic matter in the defluorinated hydrogen chloride gas is 500 ppm or less, preferably 100 ppm or less, and more preferably 1 ppm or less.

[0106] The molar ratio of fluorine atoms to metal atoms in the metal fluoride is 90% or more, and more preferably 95% or more, of the theoretical atomic molar ratio.

[0107] Preferably, 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 1-3.

[0108] Preferably, the fluorine-containing organic compound comprises one or more of fluorocarbons 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);

[0109] In formula (1), n is selected from an integer of 1 to 8, preferably from 1 to 3;

[0110] x, z are each independently selected from an integer of 0 or more, y is selected from an integer of 1 or more, and x + y + z = 2n + 2,

[0111] In formula (2), m is selected from an integer of 2 to 8, preferably from 2 to 3;

[0112] o, q are each independently selected from an integer of 0 or more, p is selected from an integer of 1 or more, and o + p + q = 2m, or o + p + q = 2m - 2.

[0113] Preferably, the fluorine-containing organic compound is one or more of trifluoromethane, difluoromonochloromethane, monofluorodichloromethane, pentafluoromonochloroethane, difluoroethene, and hexafluoropropene.

[0114] Preferably, in the hydrogen chloride gas, the content of hydrogen chloride is 50 vol% or more, preferably 90 vol% or more, more preferably 95 vol% or more.

[0115] Preferably, the hydrogen chloride gas containing the fluorine-containing organic compound further contains hydrogen fluoride, and the content of hydrogen fluoride is preferably 1 vol% or less.

[0116] Preferably, the metal compound is one or more of oxides, hydroxides, chlorides, and oxychlorides of metals; more preferably, oxides and / or hydroxides of metals.

[0117] 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, one or more of aluminum, zirconium, and chromium.

[0118] Preferably, the metal compound is one or more of aluminum oxide, aluminum hydroxide, zirconium oxide, and chromium oxide; more preferably, aluminum oxide and / or aluminum hydroxide.

[0119] Preferably, the conditions of the first reaction include: a temperature of 50 to 750°C, preferably 350 to 500°C; a volume space velocity of the hydrogen chloride gas of 1 to 10,000 h -1, preferably 50-1000h -1 .

[0120] Preferably, the reaction is carried out without adding water vapor.

[0121] Preferably, the reaction is carried out without adding oxygen.

[0122] Preferably, step 1) further comprises: a step of treating the gas product of the first reaction to remove HF to obtain a hydrogen chloride gas without fluorine; and / or a step of treating the gas product of the first reaction to remove CO to obtain a hydrogen chloride gas without fluorine.

[0123] Preferably, in step 1), the hydrogen chloride gas is sequentially passed through two or more, preferably 2-10, more preferably 3-6, reaction units filled with metal compounds to carry out the first reaction.

[0124] Preferably, after the metal compound in the reaction unit through which the hydrogen chloride gas is first passed generates metal fluoride, the reaction unit is removed, and a reaction unit filled with a metal compound is preferably added at the rear end of the reaction unit through which the hydrogen chloride gas is last passed.

[0125] Preferably, in step 1), the hydrogen chloride gas is passed from bottom to top through the reaction units filled with metal compounds to carry out the first reaction.

[0126] Preferably, after the metal compound at the lower end of the reaction unit generates metal fluoride, the metal fluoride is removed from the lower end, and a metal compound is preferably filled at the upper end of the reaction unit.

[0127] The sixth aspect of the present application provides a method for producing chlorine and metal fluoride byproduct from hydrogen chloride gas, wherein the hydrogen chloride gas contains fluorine-containing organic matter, and the method comprises:

[0128] 1) passing the hydrogen chloride gas through one or more reaction units filled with metal compounds to carry out a first reaction to obtain a hydrogen chloride gas without fluorine, and allowing part of the metal compounds to generate metal fluoride,

[0129] 2) passing the hydrogen chloride gas without fluorine obtained in step 1) and oxygen to carry out a second reaction in the presence of a catalyst,

[0130] wherein the metal compound contains L acid under the action of hydrogen chloride, and the catalyst is a hydrogen chloride catalytic oxidation catalyst for producing chlorine,

[0131] The content of fluorine-containing organic matter in the hydrogen chloride gas without fluorine is 500 ppm or less, preferably 100 ppm or less, more preferably 1 ppm or less.

[0132] The molar ratio of fluorine atoms to metal atoms in the metal fluoride is 90% or more, more preferably 95% or more, of the theoretical atomic molar ratio.

[0133] Preferably, the fluorine-containing organic compound is a fluorine-containing hydrocarbon having 1 to 8 carbon atoms, more preferably a fluorine-containing hydrocarbon having 1 to 4 carbon atoms, further preferably a fluorine-containing hydrocarbon having 1 to 3 carbon atoms.

[0134] Preferably, the fluorine-containing organic compound includes one or more of fluorine-containing hydrocarbons represented by the following formula (1) or formula (2): n H x F y Cl z Formula (1); C m H o F p Cl q Formula (2);

[0135] In formula (1), n is selected from an integer of 1 to 8, preferably from 1 to 3;

[0136] x, z are each independently selected from an integer of 0 or more, y is selected from an integer of 1 or more, and x + y + z = 2n + 2,

[0137] In formula (2), m is selected from an integer of 2 to 8, preferably from 2 to 3;

[0138] o, q are each independently selected from an integer of 0 or more, p is selected from an integer of 1 or more, and o + p + q = 2m, or o + p + q = 2m - 2.

[0139] Preferably, the fluorine-containing organic compound is one or more of trifluoromethane, difluoro-monochloromethane, monofluoro-dichloromethane, pentafluoro-monochloroethane, difluoroethene, and hexafluoropropene.

[0140] Preferably, the hydrogen chloride gas has a hydrogen chloride content of 50% by volume or more, preferably 90% by volume or more, more preferably 95% by volume or more.

[0141] Preferably, the hydrogen chloride gas containing a fluorine-containing organic compound further contains hydrogen fluoride, and the hydrogen fluoride content is preferably 1% by volume or less.

[0142] Preferably, the metal compound is one or more of an oxide, a hydroxide, a chloride, and an oxychloride of a metal; preferably an oxide and / or a hydroxide of a metal.

[0143] 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 one or more of aluminum, zirconium, and chromium.

[0144] Preferably, the metal compound is one or more of aluminum oxide, aluminum hydroxide, zirconium oxide and chromium oxide, more preferably aluminum oxide and / or aluminum hydroxide.

[0145] Preferably, the conditions of the first reaction include: a temperature of 50-750℃, preferably 360-460℃; a volume hourly space velocity of the hydrogen chloride gas of 1-10000h -1 , more preferably 50-1000h -1 .

[0146] Preferably, the first reaction is carried out without adding water vapor.

[0147] Preferably, the first reaction is carried out without adding oxygen.

[0148] Preferably, step 1) further comprises: a step of treating the gaseous product of the first reaction to remove HF to obtain a hydrogen chloride gas free of fluorine; and / or a step of treating the gaseous product of the first reaction to remove CO to obtain a hydrogen chloride gas free of fluorine.

[0149] Preferably, in step 2), the conditions of the second reaction include: a temperature of 280-420℃, more preferably 320-390℃; a molar ratio of hydrogen chloride to oxygen in the hydrogen chloride gas free of fluorine of 0.25-10:1, more preferably 0.5-4:1.

[0150] Preferably, the temperature of the first reaction is 0-180℃ higher than the temperature of the second reaction.

[0151] Preferably, in step 1), the hydrogen chloride gas is sequentially passed through 2 or more, preferably 2-10, more preferably 3-6, reaction units filled with metal compounds to carry out the first reaction.

[0152] Preferably, after the metal compound in the reaction unit through which the hydrogen chloride gas is first passed generates metal fluoride, the reaction unit is removed, and a reaction unit filled with metal compound is preferably added at the rear end of the reaction unit through which the hydrogen chloride gas is last passed.

[0153] Preferably, in step 1), the hydrogen chloride gas is passed through the reaction units filled with metal compounds from bottom to top to carry out the first reaction.

[0154] Preferably, after the metal compound at the lower end of the reaction unit generates metal fluoride, the metal fluoride is removed from the lower end, and a metal compound is preferably filled at the upper end of the reaction unit.

[0155] By the above technical solution, the following beneficial effects can be achieved:

[0156] 1) The treatment method of the fluorine-containing organic matter provided by the present application is simple and easy to operate, which only needs to contact the fluorine-containing organic matter with a specific metal compound in the presence of hydrogen chloride. The method provided by the present application can be used to treat various fluorine-containing organic matters and remove the fluorine-containing organic matters (which can be removed to below 0.01 ppm), and the treatment effect of the fluorine-containing organic matter is excellent;

[0157] 2) The method provided by the present application can effectively solve the problem of the removal of hydrogen chloride byproduct in the prior art, and can efficiently remove various fluorine-containing organic matters in the byproduct hydrogen chloride, so as to obtain purified hydrogen chloride gas;

[0158] 3) Further, by using the method provided by the present application, the bottleneck of the prior art that the byproduct hydrogen chloride in the organic fluorine chemical industry cannot be directly used for the preparation of chlorine gas by using a conventional hydrogen chloride catalytic oxidation catalyst for chlorine gas can be broken through, and the industrial chlorine gas production can be realized by using hydrogen chloride containing fluorine-containing organic matter as raw material, and the production can be carried out stably and continuously for a long time;

[0159] 4) By using the method provided by the present application, the fluorine in the fluorine-containing organic matter is fixed and recycled in the form of metal fluoride during the reaction of the fluorine-containing organic matter and the metal compound, and the carbon atoms in the fluorine-containing organic matter are oxidized to carbon monoxide or carbon dioxide and directly discharged, without producing other solid waste. At the same time, the added value of the metal compound is improved, and products with high added value such as aluminum fluoride can be prepared. For example, by using the method provided by the present application, the F content in the prepared aluminum fluoride can be as high as 61 wt%, the aluminum content can be as high as 31.5 wt%, and the quality of the aluminum fluoride product can meet the requirements of AF-0 grade in GB / T 4292-2017 "Aluminum Fluoride";

[0160] 5) By using the method provided by the present application, the purified hydrogen chloride gas can be co-produced with metal fluoride, or the hydrogen chloride gas can be used to produce chlorine gas, and the production process can be realized continuously. The treatment problem of hydrogen chloride containing fluorine-containing organic matter can be solved, and high-value metal fluoride products can be prepared, which can bring significant economic benefits. BRIEF DESCRIPTION OF DRAWINGS

[0161] FIG. 1 is an XPS total spectrum spectrum of the solid substance prepared in Example 1;

[0162] FIG. 2 is an F spectrum of the solid substance prepared in Example 1. DETAILED DESCRIPTION

[0163] 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 regarded as prior art simply because they are described in the background section.

[0164] 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.

[0165] First, the fluorinated organic compounds described herein will be explained, and the fluorinated organic compounds described herein are applicable to the first to sixth aspects of this invention.

[0166] Unless otherwise specified, the fluorinated organic compounds involved in this invention refer to organic compounds in which the hydrogen atoms bonded to carbon atoms in the organic compound 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, and monofluorinated or polyfluorinated organic compounds in which some carbon-hydrogen bonds are converted into carbon-fluorine bonds.

[0167] 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.

[0168] In addition, in this invention, the fluorinated organic compounds include, but are not limited to, fluorinated alkanes, fluorinated alkenes, fluorinated alkynes, fluorinated aromatics, and fluorinated carboxylic acids.

[0169] 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 3 or less.

[0170] 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.

[0171] In some embodiments of the present invention, the fluorinated organic compound is preferably a fluorinated hydrocarbon, more preferably a fluorinated alkane, a fluorinated olefin or a fluorinated alkyne.

[0172] As the aforementioned fluorinated alkanes, one or more of the fluorinated alkanes represented by the following formula (1) can be selected: Cn H x F y Cl z Formula (1);

[0173] In Formula (1), n is selected from an integer of 1 to 8, preferably from an integer of 1 to 4, more preferably from an integer of 1 to 3, that is, n may, for example, be 1, 2, 3.

[0174] x and z are each independently selected from an integer of 0 or more, y is selected from an integer of 1 or more, and x + y + z = 2n + 2.

[0175] As the above-mentioned fluorine-containing olefin, one or more selected from the group consisting of fluorine-containing olefins represented by the following Formula (2) can be selected: C m H o F p Cl q Formula (2);

[0176] In Formula (2), m is selected from an integer of 2 to 8, preferably from an integer of 2 to 3, may, for example, be 2, 3.

[0177] o and q are each independently selected from an integer of 0 or more, p is selected from an integer of 1 or more, and o + p + q = 2m.

[0178] As the above-mentioned fluorine-containing acetylene, one or more selected from the group consisting of fluorine-containing acetylenes represented by the following Formula (2) can be selected: C m H o F p Cl q Formula (2);

[0179] In Formula (2), m is selected from an integer of 2 to 8, preferably from an integer of 2 to 3, may, for example, be 2, 3.

[0180] o and q are each independently selected from an integer of 0 or more, p is selected from an integer of 1 or more, and o + p + q = 2m - 2.

[0181] In the above Formula (1) and Formula (2), C represents a carbon atom, H represents a hydrogen atom, F represents a fluorine atom, and Cl represents a chlorine atom.

[0182] In the present application, as the fluorine-containing organic compound, one or more of monofluoromethane, difluoromethane, trifluoromethane, tetrafluoromethane, monofluoromonochloromethane, monofluorodichloromethane, monofluorotrichloromethane, difluoromonochloromethane, difluorodichloromethane, trifluoromonochloromethane, monofluoroethane, difluoroethane, trifluoroethane, tetrafluoroethane, pentafluoroethane, hexafluoroethane, chloromonofluoroethane, chlorodifluoroethane, chlorotrifluoroethane, chlorotetrafluoroethane, chloropentafluoroethane, dichloromonofluoroethane, dichlorodifluoroethane, dichlorotrifluoroethane, dichlorotetrafluoroethane, trichloromonofluoroethane, trichlorodifluoroethane, trichlorotrifluoroethane, tetrachloromonofluoroethane, tetrachlorodifluoroethane, pentafluoroethane, tetrafluoroethylene, trifluoroethylene, difluoroethylene, fluoroethylene, trifluorochloroethylene, chlorodifluoroethylene, hexafluoropropylene can be listed.

[0183] According to the present application, preferably, the fluorine-containing organic compound is one or more of monofluoromethane, difluoromethane, trifluoromethane, difluoromonochloromethane, monofluorodichloromethane, difluoroethane, trifluoroethane, tetrafluoroethane, difluoromonochloroethane, pentafluoromonochloroethane, difluoroethylene, tetrafluoroethylene, trifluorochloroethylene, hexafluoropropylene.

[0184] In some particularly preferred embodiments of the present application, the fluorine-containing organic compound is one or more of trifluoromethane, difluoromonochloromethane, monofluorodichloromethane, pentafluoromonochloroethane, difluoroethylene, and hexafluoropropylene.

[0185] Next, the metal compound according to the present application will be described. The metal compound described herein is applicable to the first to sixth aspects of the present application.

[0186] According to the present application, the metal compound in the presence of hydrogen chloride has L acid.

[0187] In the present application, the L acid refers to Lewis acid, which is an acid defined in the Lewis acid-base theory. According to the definition of the theory, the L acid refers to a substance (including ions, atomic groups, or molecules) that can accept an electron pair.

[0188] In the present application, the L acid accepts an electron pair to form a chemical bond with the reactant, thereby activating the reactant, promoting the progress of the reaction, and further affecting the reaction path and product distribution.

[0189] In the present application, whether the L acid exists in the presence of hydrogen chloride can be determined by infrared spectrometer (Nicolet 380 infrared spectrometer, USA) using pyridine adsorption infrared method. Specifically, the metal compound sample is self-supported and pressed into a tablet, which is placed in the in-situ cell of the infrared spectrometer. Hydrogen chloride gas is introduced and kept sealed. The temperature is heated to 350°C and kept at this temperature for 30 minutes. Then, vacuum is extracted to 10 -3Pa, and the sample was kept at this temperature for 1 hour to remove the hydrogen chloride gas physically adsorbed on the surface of the sample. Then, after cooling to room temperature (25°C), pyridine vapor was introduced to keep the adsorption balance for 30 minutes, and then the temperature was raised to 200°C, and the vacuum was re-pulled to 10 -3 Pa and desorbed for 30 minutes at this vacuum, and the spectrum was taken at room temperature with a scanning range of 1400-1700 cm -1 If a characteristic peak is observed at 1450±5 cm -1 , which is caused by the symmetric stretching vibration peak of the pyridine ring when the nitrogen atom of pyridine coordinates with the metal ion in the metal compound of L acid), it is determined that the metal compound has L acid under the action of hydrogen chloride.

[0190] The inventors have confirmed through experiments that the metal compound having L acid under the action of hydrogen chloride measured by the above-mentioned test method can meet the property requirements of the metal compound of the present application, and such metal compounds can be applied to the methods described in the first to sixth aspects and achieve the corresponding purposes of the present application. The test conditions in the above-mentioned test method do not limit the application of the present application.

[0191] In addition, it should be understood that, in theory, the L acid can be possessed by the metal compound itself or generated after the metal compound contacts with hydrogen chloride, which is not limited by the present application. The above-mentioned cases are included in the scope of the present application, and the present application does not make specific exploration on this. As long as the L acid can be detected by the above-mentioned test method, the corresponding metal compound meets the requirements of the present application.

[0192] In the present application, preferably, the metal compound is one or more of oxides, hydroxides, chlorides and oxychlorides of the metal; and more preferably, the metal compound is one or more of oxides and / or hydroxides of the metal.

[0193] In addition, 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, the metal is one or more of aluminum, zirconium and chromium.

[0194] Preferably, the metal compound is one or more of aluminum oxide, aluminum hydroxide, hydrated aluminum hydroxide, aluminum chloride, aluminum oxychloride, zirconium oxide, chromium oxide, zirconium oxychloride and zirconium hydroxide.

[0195] In some preferred embodiments of the present application, the metal compound is one or more of aluminum oxide, zirconium oxide, chromium oxide and aluminum hydroxide.

[0196] In a particularly preferred embodiment of the present application, the metal compound is aluminum oxide.

[0197] In addition, when the metal compound is alumina, the alumina can be one or more of any crystal form of alumina without particular limitation. In view of better reactivity, β-alumina and / or γ-alumina can be preferred.

[0198] In another particularly preferred embodiment of the present application, the metal compound is aluminum hydroxide.

[0199] In addition, the present application is not particularly limited in particle size of the metal compound, and those skilled in the art can make appropriate selection according to actual needs.

[0200] In the present application, in order to increase the contact area with the fluorine-containing organic matter and facilitate removal of the fluorine-containing organic matter, preferably, the particle size of the metal compound is 0.001-5 mm.

[0201] In addition, in the present application, the particle size of the metal compound can also be appropriately optimized according to actual process needs. For example, when a fluidized bed reactor is used, the particle size of the metal compound is preferably 0.001-0.2 mm, at which the metal compound is in the form of microspheres, which facilitates improvement of its flowability in the reaction and in turn improves the reaction efficiency; when a fixed bed or moving bed reactor is used, the particle size of the metal compound is preferably 0.1-5 mm, at which the metal compound is in the form of small spheres, which facilitates replacement and other operations.

[0202] Those skilled in the art can understand that the above-defined particle size range is made for process and operation needs, and the metal compound in the present application is not limited by the particle size.

[0203] The above limitations and descriptions of the fluorine-containing organic matter and the metal compound in the present application are applicable to each aspect of the present application to be described below. Unless otherwise specified, the fluorine-containing organic matter and the metal compound involved in each aspect of the present application below are as described above, and will not be described again hereinafter.

[0204] Next, the hydrogen chloride gas according to the second, fourth, fifth and sixth aspects of the present application is described.

[0205] In the present application, the hydrogen chloride gas contains a fluorine-containing organic matter, which can be a by-product from various organic fluorine chemical production processes. For example, it can come from fluorine-containing polymer production processes, fluorine-containing refrigerant preparation processes, fluorinated solvent production processes, fluorine-containing pharmaceutical production processes, fluorine-containing pesticide production processes and fluorine-containing surface lubricant production processes, etc., and the present application is not particularly limited in the source of the hydrogen chloride gas containing a fluorine-containing organic matter.

[0206] In addition, the specific composition of the hydrogen chloride gas containing fluorine-containing organic compounds is not particularly limited in the present application, and depending on the source of generation, the hydrogen chloride gas can contain, in addition to the fluorine-containing organic compounds, conventional impurities such as HF, fluorinated sulfur (e.g., sulfur hexafluoride, sulfur tetrafluoride), and the like, and the treatment method according to the present application can also purify such hydrogen chloride gas.

[0207] In the present application, the content of hydrogen chloride in the hydrogen chloride gas containing fluorine-containing organic compounds can be, for example, 50 vol% or more, preferably 60 vol% or more, more preferably 70 vol% or more, further preferably 80 vol% or more, and particularly preferably 90 vol% or more.

[0208] In preferred embodiments of the present application, the content of hydrogen chloride in the hydrogen chloride gas containing fluorine-containing organic compounds is 95 vol% or more.

[0209] In addition, the hydrogen chloride gas containing fluorine-containing organic compounds can also contain hydrogen fluoride, and the content of hydrogen fluoride can be, for example, 10 vol% or less, preferably 5 vol% or less, and more preferably 1 vol% or less. The metal compound according to the present application can also remove hydrogen chloride from the hydrogen chloride gas.

[0210] As a more specific composition of the hydrogen chloride gas, for example, it can contain 50 to 99.9 vol% of HCl, 0.1 to 50 vol% of the fluorine-containing organic compound; or 80 to 99.5 vol% of HCl, 0.5 to 20 vol% of the fluorine-containing organic compound; or 90 to 99.9 vol% of HCl, 0.1 to 10 vol% of the fluorine-containing organic compound, and in addition, it can also contain HF, and the content of HF is preferably 1 vol% or less.

[0211] Preferably, the hydrogen chloride gas containing fluorine-containing organic compounds contains 95 to 99.9 vol% of HCl, 0.1 to 5 vol% of the fluorine-containing organic compound, and 0 to 1 vol% of HF.

[0212] The above describes the hydrogen chloride gas as a gas to be treated (raw gas) according to the second, fourth, fifth, and sixth aspects of the present application. Unless otherwise specified, the hydrogen chloride gas according to the above aspects of the present application is as described above, and will not be described again hereinafter.

[0213] In addition, the hydrogen chloride in "in the presence of hydrogen chloride" according to the first and third aspects of the present application can be the hydrogen chloride gas containing fluorine-containing organic compounds described above, or various hydrogen chlorides conventionally used in the art, and unless otherwise specified, the hydrogen chloride according to the first and third aspects of the present application is not particularly limited.

[0214] Hereinafter, the first to sixth aspects of the present application will be described in more detail.

[0215] The first aspect of the present application provides a method for treating a fluorine-containing organic compound, wherein the method comprises: contacting the fluorine-containing organic compound with a metal compound in the presence of hydrogen chloride to generate a metal fluoride, wherein the metal compound is capable of providing L acid in the presence of hydrogen chloride.

[0216] According to a specific embodiment of the present application, there is provided a method for treating a fluorine-containing organic compound, which comprises: contacting the fluorine-containing organic compound with a metal compound in the presence of hydrogen chloride to generate a metal fluoride, wherein the metal compound is one or more of an oxide, a hydroxide, a chloride and a oxychloride of a metal, preferably one or both of an oxide and a hydroxide of a metal; 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, preferably one or more of aluminum, chromium and zirconium.

[0217] Further, in a preferred embodiment of the present application, the metal compound is one or more of aluminum oxide, aluminum hydroxide, zirconium oxide and chromium oxide.

[0218] According to the first aspect of the present application, the method does not have a specific requirement for the relative content of hydrogen chloride and the fluorine-containing organic compound, and theoretically, as long as hydrogen chloride is present and the metal compound is capable of providing L acid.

[0219] According to the present application, the molar ratio of the hydrogen chloride to the fluorine-containing organic compound can be, for example, 1:0.001-10000, preferably 1:0.01-100, and more preferably 1:0.1-10.

[0220] In addition, in a preferred embodiment of the present application, the method for treating the fluorine-containing organic compound comprises: contacting a mixture of the fluorine-containing organic compound and hydrogen chloride with the metal compound to remove the fluorine-containing organic compound and generate a metal fluoride.

[0221] The content of the fluorine-containing organic compound in the mixture of the fluorine-containing organic compound and hydrogen chloride is not particularly limited, and for example, the content of the fluorine-containing organic compound in the mixture can be 60% by volume or less, specifically 1% by volume, 10% by volume, 15% by volume, 20% by volume, 25% by volume, 30% by volume, 35% by volume, 40% by volume, 45% by volume, 50% by volume, 60% by volume, and a range formed by any two of these point values, with the balance being hydrogen chloride.

[0222] According to the first aspect of the present application, the treatment method does not have a specific requirement for the relative amounts of the metal compound and the fluorine-containing organic matter. It is understood that the metal compound can be used in excess when the removal of the fluorine-containing organic matter is targeted. The relative amounts of the two can be determined by the person skilled in the art according to the actual needs, and the present application does not have a specific limitation thereon.

[0223] According to the present application, the conditions of the contacting are determined according to the reaction of the fluorine-containing organic matter with the metal compound and the removal of the fluorine-containing organic matter. For example, the temperature of the contacting can be 50-750°C. In addition, the volume space velocity of the mixed gas of the fluorine-containing organic matter and hydrogen chloride can be 1-10000h -1 -1. Preferably, the conditions of the contacting include a temperature of 350-500°C and a volume space velocity of the mixed gas of the fluorine-containing organic matter and hydrogen chloride of 50-1000h -1 -1. In this way, the removal efficiency can be improved while ensuring the treatment effect of the fluorine-containing organic matter.

[0224] In the present application, the volume space velocity refers to the amount of the mixed gas treated by the metal compound per unit volume per unit time, and the unit is m 3 / (m 3 ·h.

[0225] In addition, in the present application, as described above, the metal compound is preferably a metal oxide or a hydroxide, and in the reaction process, the oxygen atoms provided by the metal compound can combine with the carbon atoms in the fluorine-containing organic matter to generate carbon oxides (such as carbon monoxide and carbon dioxide), and are discharged with the gas after the reaction, thereby avoiding the phenomenon of carbon deposition on the surface of the metal compound.

[0226] When the metal compound contains oxygen atoms, for example, when the metal compound is a metal oxide or a hydroxide, in the present application, in order to prevent the generated metal fluoride such as aluminum fluoride from being decomposed by water, the contacting is preferably performed without the addition of water vapor.

[0227] In the present application, the addition of water vapor refers to that the water vapor is not additionally added, and the content of the water vapor is not more than 0.5% by volume, based on the total volume of the hydrogen chloride and the fluorine-containing organic matter being 100% by volume.

[0228] In addition, when the metal compound contains oxygen atoms, for example, when the metal compound is a metal oxide or a hydroxide, in order to reduce the generation of by-products such as oxygen-containing fluorides and affect the degree of metal fluorination, the contacting is preferably performed without the addition of oxygen.

[0229] In the present application, the non-addition of oxygen means that no additional oxygen is added, and the content of oxygen is not more than 0.5% by volume, calculated based on the total volume of the hydrogen chloride and the fluorine-containing organic matter.

[0230] In the second to sixth aspects of the present application, when the metal compound contains oxygen atoms, for example, when the metal compound is a metal oxide or a hydroxide, the corresponding contact or reaction is also preferably carried out without the addition of water vapor and / or without the addition of oxygen. The reasons are as described above, and will not be repeated hereinafter.

[0231] By the method provided in the first aspect of the present application, the fluorine-containing organic matter can be efficiently removed in the presence of hydrogen chloride, and at the same time, the fluorine is fixed in the form of metal fluoride. Thus, not only the treatment problem of the fluorine-containing organic matter is overcome, but also a metal fluoride product with high added value such as aluminum fluoride can be produced, and no solid hazardous waste industrial by-product is generated in the process.

[0232] In addition, by using the method provided in the first aspect of the present application, the fluorine-containing organic matter can be removed to below 500 ppm, preferably to below 100 ppm, and more preferably to below 1 ppm.

[0233] In a particularly preferred embodiment of the present application, the fluorine-containing organic matter is removed to the extent that it cannot be detected by a gas chromatograph, and the detection limit (the minimum concentration of detection) is 0.01 ppm.

[0234] In addition, by using the method provided in the first aspect of the present application, the molar ratio of fluorine atoms to metal atoms in the generated metal fluoride can be more than 90% of the theoretical atomic molar ratio of the two, and more preferably more than 95%.

[0235] In the present application, the theoretical atomic molar ratio of fluorine atoms to metal atoms refers to the ratio of the absolute value of the valence state of the metal to the absolute value of the valence state of the fluorine in the metal fluoride. For example, in aluminum fluoride, the valence state of aluminum is +3, and the valence state of fluorine is -1, so the theoretical molar ratio of fluorine atoms to aluminum atoms is 3 (i.e., |+3|: |-1|).

[0236] The molar ratio of fluorine atoms to metal atoms in the metal fluoride can be calculated by quantitatively analyzing the elemental content (in the present application, the quantitative analysis is carried out by using X-ray photoelectron spectroscopy (XPS) using an X-ray photoelectron spectrometer of PHI Quantera II model manufactured by Japan ulvac-phi Co., Ltd.).

[0237] The second aspect of the present application provides a method for purifying hydrogen chloride gas, wherein the hydrogen chloride gas contains fluorine-containing organic compounds, and the method comprises: contacting the hydrogen chloride gas with a metal compound to obtain fluorine-removed hydrogen chloride gas and generate a metal fluoride, wherein the metal compound is an L acid in the presence of hydrogen chloride.

[0238] According to a specific embodiment of the present application, a method for purifying hydrogen chloride gas, wherein the hydrogen chloride gas contains fluorine-containing organic compounds, and the method comprises: contacting the hydrogen chloride gas with a metal compound to obtain fluorine-removed hydrogen chloride gas and generate a metal fluoride, wherein the metal compound is one or more of an oxide, a hydroxide, a chloride and a oxychloride of a metal, preferably one or both of an oxide and a hydroxide of a metal; 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, preferably one or more of aluminum, chromium and zirconium.

[0239] The method for purifying hydrogen chloride gas according to the second aspect of the present application is intended to remove fluorine-containing organic compound impurities in hydrogen chloride, by contacting hydrogen chloride gas containing fluorine-containing organic compounds with a metal compound to remove the fluorine-containing organic compounds in the presence of hydrogen chloride, and fix fluorine in the fluorine-containing organic compounds in the form of a metal fluoride, thereby removing the fluorine-containing organic compounds in the hydrogen chloride gas and purifying the hydrogen chloride.

[0240] In the present application, the fluorine-removed hydrogen chloride gas refers to hydrogen chloride gas from which fluorine-containing organic compounds are removed, and preferably, the fluorine-removed hydrogen chloride gas refers to hydrogen chloride gas from which fluorine-containing organic compounds and fluorine-containing inorganic compounds (e.g. HF) are removed.

[0241] It can be understood by those skilled in the art that, according to the second aspect of the present application, when the purpose is to remove fluorine-containing organic compounds in hydrogen chloride gas, the metal compound can be used in excess, which is not limited by the present application.

[0242] According to the second aspect of the present application, the conditions of the contacting are such that the fluorine-containing organic compounds can react with the metal compound and the fluorine-containing organic compounds can be removed. For example, the temperature of the contacting can be 50-750℃, and the volume space velocity of the hydrogen chloride gas containing fluorine-containing organic compounds can be 1-10000h -1 -1. Preferably, the conditions of the contacting include a temperature of 300-500℃ and a volume space velocity of the hydrogen chloride gas containing fluorine-containing organic compounds of 50-1000h -1 -1. In this way, the removal efficiency of the fluorine-containing organic compounds can be further improved, the purification degree of the hydrogen chloride gas can be improved, and the treatment effect of the fluorine-containing organic compounds can be further improved.

[0243] According to the method provided by the second aspect of the present application, the organic fluorides in the hydrogen chloride gas containing fluorine-containing organic substances can be removed, and the purification of the by-product hydrogen chloride in the organic fluorine-containing chemical industry can be realized.

[0244] In addition, according to the method provided by the second aspect of the present application, the fluorine-containing organic substances in the hydrogen chloride gas containing fluorine-containing organic substances can be removed to 500 ppm or less, more preferably 100 ppm or less, and further preferably 1 ppm or less.

[0245] In a preferred embodiment of the present application, according to the method provided by the second aspect of the present application, the fluorine-containing organic substances in the hydrogen chloride gas containing fluorine-containing organic substances can be removed to the extent that the gas phase spectrometer cannot detect, and the detection limit (the minimum concentration of detection) is 0.01 ppm.

[0246] Therefore, according to the method provided by the second aspect of the present application, the purification of the hydrogen chloride gas can be realized, the fluorine-containing organic substances are converted into metal fluorides, CO, CO2, etc., the purification is realized while avoiding pollution to the environment, and a metal fluoride product with high added value can also be prepared.

[0247] In addition, as described above, a small amount of HF can exist in the hydrogen chloride gas containing fluorine-containing organic substances, and the HF can be removed together with the fluorine-containing organic substances by the method provided by the second aspect of the present application. If a small amount of HF still exists in the obtained fluorine-removed hydrogen chloride gas, it can be further removed by conventional means such as adsorption treatment.

[0248] In addition, a small amount of CO and CO2 can exist in the fluorine-removed hydrogen chloride gas obtained by the contact. According to the needs, the CO can be removed by conventional means such as oxidation treatment, and a small amount of CO2 can generally be allowed to exist, for example, a small amount of CO2 does not affect the subsequent reaction of preparing chlorine gas from hydrogen chloride. Of course, if necessary, it can also be further removed by conventional methods in the art.

[0249] On the other hand, by the method provided by the second aspect of the present application, the purity of the generated metal fluoride can also be controlled, for example, preferably, the molar ratio of fluorine atoms to metal atoms in the generated metal fluoride is 90% or more, more preferably 95% or more, of the theoretical atomic molar ratio of the two.

[0250] Therefore, according to the method provided by the second aspect of the present application, the purification of the hydrogen chloride gas containing fluorine-containing organic substances can be realized, and the hydrogen chloride gas from which the fluorine-containing organic substances are removed can be obtained. At the same time, according to the needs, a high-purity metal fluoride product can also be prepared.

[0251] The third aspect of the present application provides a method for preparing a metal fluoride, which comprises: contacting a fluorine-containing organic compound with a metal compound in the presence of hydrogen chloride to generate the metal fluoride, wherein the metal compound is subjected to L acid in the presence of hydrogen chloride.

[0252] According to a specific embodiment of the present application, a method for preparing a metal fluoride is provided, which comprises: contacting a fluorine-containing organic compound with a metal compound in the presence of hydrogen chloride to generate the metal fluoride, wherein the metal compound is one or more of an oxide, a hydroxide, a chloride and a oxychloride of a metal, preferably one or both of an oxide and a hydroxide of a metal; 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, preferably one or more of aluminum, chromium and zirconium.

[0253] In a particularly preferred embodiment of the present application, the metal compound is one or more of aluminum oxide, aluminum hydroxide, zirconium oxide and chromium oxide.

[0254] In a preferred embodiment of the present application, the method comprises: contacting a hydrogen chloride gas containing the fluorine-containing organic compound with the metal compound to remove the fluorine-containing organic compound in the hydrogen chloride gas and generate the metal fluoride.

[0255] In addition, in a particularly preferred embodiment of the present application, the metal compound is an aluminum-containing compound, and further preferably aluminum oxide and / or aluminum hydroxide. In this way, not only is the aluminum-containing compound raw material inexpensive and readily available, but an aluminum fluoride product that meets market requirements can also be prepared.

[0256] Aluminum fluoride is widely used in industry, for example, it can be used as a component of an electrolytic bath in the aluminum smelting industry, as a high-quality flux and deoxidizer in the metallurgical industry, and as an important catalyst, flame retardant and drying agent in the chemical industry. It not only promotes the progress of various chemical reactions, but also can be used for drying various chemicals, etc., and is a very important chemical raw material.

[0257] In the prior art, aluminum fluoride generally needs to be prepared by dry or wet process, and the preparation process is relatively complex. Moreover, HF and the like with strong corrosivity are required during preparation, which not only has high preparation cost and complex process, but also poses a threat to the health and safety of the operating personnel.

[0258] In the present application, by selecting an aluminum-containing compound as the metal compound, not only is the aluminum-containing compound raw material inexpensive and readily available, but the above-mentioned widely used aluminum fluoride product can also be prepared, further realizing the resource utilization of the fluorine-containing organic compound, significantly improving its economic benefits, and the production process is short and simple to operate, thereby providing a new method for industrial preparation of aluminum fluoride products.

[0259] On the other hand, as described above, it is understood by those skilled in the art that, when aiming at removing fluorine-containing organic matter as much as possible, for example, in the step 1) of the first aspect, the second aspect, and the fourth aspect, the sixth aspect of the present application described later, an excess amount of metal compound can be provided to improve the removal effect of the fluorine-containing organic matter; conversely, when aiming at efficiently producing high-quality metal fluoride as much as possible, for example, in the third aspect of the present application, an excess amount of fluorine-containing organic matter can be provided with respect to the metal compound.

[0260] Therefore, in the third aspect of the present application, the amounts of the fluorine-containing organic matter and the metal compound are not particularly limited, and those skilled in the art can appropriately select them according to the actual needs of the reaction purpose and the like. It is understood by those skilled in the art that, when aiming at the production of metal fluoride, the conditions of the reaction can be appropriately adjusted, for example, a raw material having a higher content of fluorine-containing organic matter can be selected, the space velocity of the reaction raw material can be increased, the passage of organic fluoride can be maintained for a longer time, and the like. These conditions can be appropriately adjusted and selected by those skilled in the art, and these specific reaction conditions do not limit the present application.

[0261] In addition, according to the third aspect of the present application, the conditions of the contact can include a temperature of 50 to 750°C and a volume space velocity of the mixed gas of the fluorine-containing organic matter 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 matter and hydrogen chloride of 50 to 1,000 h -1 -1. Thereby, under the above preferred conditions, the production efficiency and the quality of the metal fluoride can be further improved.

[0262] According to a particularly preferred embodiment of the present application, the metal compound is aluminum oxide and / or aluminum hydroxide, and the method includes contacting the hydrogen chloride gas containing the fluorine-containing organic matter with the aluminum oxide and / or the aluminum hydroxide to produce aluminum fluoride.

[0263] In addition, by the method of the third aspect of the present application, the molar ratio of fluorine atoms to metal atoms in the produced metal fluoride can be 90% or more, more preferably 95% or more, of the theoretical atomic molar ratio. That is, by the method of the third aspect of the present application, a high-purity metal fluoride product can be produced.

[0264] Thereby, aluminum fluoride, which is widely used in industry and in large demand, can be produced in a simple method at a low cost.

[0265] According to a preferred embodiment of the present application, the content of F in the prepared aluminum chloride can be up to 61.0% by weight or more, and the content of Al can be up to 31.5% by weight or more, which can meet the chemical composition requirements of AF-0 in GB / T 4292-2017 "Aluminum Fluoride". Not only the problem of handling hydrogen chloride containing fluorine-containing organic matter is solved, but also the preparation of high-value fluorides is realized, and significant economic benefits are generated.

[0266] The fourth aspect of the present application provides a method for preparing chlorine gas from hydrogen chloride gas containing fluorine-containing organic matter, which comprises:

[0267] 1) first contacting the hydrogen chloride gas with a metal compound to obtain fluorine-free hydrogen chloride gas and generate a metal fluoride;

[0268] 2) second contacting the fluorine-free hydrogen chloride gas obtained in step 1) with oxygen in the presence of a catalyst,

[0269] 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.

[0270] According to a specific embodiment of the present application, a method for preparing chlorine gas from hydrogen chloride gas containing fluorine-containing organic matter is provided, which comprises:

[0271] 1) first contacting the hydrogen chloride gas with a metal compound to obtain fluorine-free hydrogen chloride gas and generate a metal fluoride;

[0272] 2) second contacting the fluorine-free hydrogen chloride gas obtained in step 1) with oxygen in the presence of a catalyst,

[0273] wherein the metal compound is one or more of metal oxides, metal hydroxides, metal chlorides and metal oxychlorides, preferably one or two of metal oxides and metal hydroxides; 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 the metal in the metal compound is preferably one or more of aluminum, chromium and zirconium; and the catalyst is a hydrogen chloride catalytic oxidation catalyst for preparing chlorine gas.

[0274] In a particularly preferred embodiment of the present application, the metal compound is one or more of aluminum oxide, aluminum hydroxide, zirconium oxide and chromium oxide.

[0275] As mentioned above, there are significant difficulties in the industrial production of chlorine gas using the prior art method with hydrogen chloride containing fluorine-containing organic compounds as raw material, the reaction cannot be carried out stably for a long time, and obvious carbon deposition occurs on the surface of the catalyst. The inventors of the present application have realized the removal of fluorine-containing organic compounds in hydrogen chloride by using a special hydrogen chloride atmosphere, thereby enabling the industrial production of chlorine gas using hydrogen chloride containing fluorine-containing organic compounds as raw material.

[0276] According to the fourth aspect of the present application, in step 1), the hydrogen chloride gas (hydrogen chloride gas containing fluorine-containing organic compounds) is subjected to first contact with a metal compound to obtain fluorine-removed hydrogen chloride gas.

[0277] This step aims to remove the fluorine-containing organic compounds contained in the hydrogen chloride to eliminate the influence of the fluorine-containing organic compounds on the catalyst used in the subsequent catalytic oxidation of hydrogen chloride to produce chlorine gas, and to fix the fluorine therein in the form of metal fluoride.

[0278] According to the fourth aspect of the present application, the conditions of the first contact include: the temperature is 50-750℃, preferably 360-460℃; the volume space velocity of the hydrogen chloride gas is 1-10000h -1 , preferably 50-1000h -1 . The above preferred conditions not only can efficiently achieve the removal of fluorine-containing organic compounds, but also match the active temperature of the hydrogen chloride to chlorine gas catalyst used in the subsequent step 2), and there is no need for further temperature adjustment between the first contact and the second contact.

[0279] That is, by using the above preferred conditions of the first contact, the fluorine-removed hydrogen chloride gas obtained in step 1) can directly enter step 2) to participate in the reaction of the second contact without adjusting the temperature, thereby significantly reducing energy consumption, improving energy utilization, and reducing the complexity of operation.

[0280] In addition, it can be understood that the purpose and specific operation method of step 1) of the fourth aspect of the present application are similar to the method of purifying hydrogen chloride gas described in the second aspect of the present application. Unless otherwise specified, the conditions and specific selection of step 1) of the fourth aspect of the present application can be referred to the second aspect of the present application.

[0281] In the present application, as mentioned above, the hydrogen chloride gas raw material can contain HF, and a small amount of HF can be produced in the first contact, and this part of HF will be in-situ absorbed by the corresponding metal compound during the first contact. After the first contact, HF generally does not exist in the first contact product.

[0282] In addition, if the first contact product still contains HF, the gas phase product obtained by the first contact can be subjected to HF removal treatment to remove the HF therein, so as to avoid affecting the subsequent second contact, i.e. the preparation of chlorine gas.

[0283] Here, the HF removal treatment can be carried out by any method conventional in the art without particular limitation, for example, the HF in the gaseous product obtained after the first contact can be removed by chemical adsorption or the like, and the adsorbent used can be SCAF-10 hydrogen fluoride adsorbent produced by Sinopec Catalyst Co., Ltd. or the like, which is a conventional operation in the art and will not be described in detail here.

[0284] It can be understood that when the above HF removal treatment is carried out, the fluorine-free hydrogen chloride gas in step 2) is the product after the HF removal treatment.

[0285] In addition, in the present application, a small amount of CO can also be produced by the first contact described above. Therefore, preferably, the method can further comprise a step of carrying out a CO removal treatment on the gaseous product obtained after the first contact.

[0286] Here, the CO removal treatment can be carried out by any means for removing CO conventional in the art without 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. or the like can be used to carry out the CO removal treatment, and the catalytic oxidation treatment of carbon monoxide is a conventional operation in the art and will not be described in detail here.

[0287] It can be understood that when the above CO removal treatment is carried out, the fluorine-free hydrogen chloride gas in step 2) is the product after the CO removal treatment.

[0288] In addition, the CO2 produced by the CO removal treatment, or part of the CO2 present in the fluorine-free hydrogen chloride gas, will not have a significant negative impact on the subsequent preparation of chlorine gas from hydrogen chloride, so even if a small amount of CO2 is present in the fluorine-free hydrogen chloride gas, it can also not be removed separately.

[0289] Thus, by the above step 1), the fluorine-containing organic matter in the hydrogen chloride gas is removed, and HF, CO and the like that are not desired to be present can be further selectively removed, to obtain fluorine-free hydrogen chloride gas and generate metal fluoride.

[0290] Then, step 2) is carried out, i.e., the fluorine-free hydrogen chloride gas obtained in step 1) is subjected to a second contact with oxygen in the presence of a catalyst. This step is intended to prepare chlorine gas from the hydrogen chloride after removing fluorine.

[0291] The catalyst used in the above step 2) is not particularly limited and can be any catalyst conventionally used in the hydrogen chloride catalytic oxidation process for producing chlorine gas. For example, the catalyst can include a carrier such as alumina, silica, titania, ceria, tin dioxide, etc., and an active component supported on the carrier, which can contain oxides of copper, zirconium, ruthenium, rare earth elements, alkali metals, etc.

[0292] In the catalyst, the content of the carrier can be 60-98% by weight, and the content of the active component can be 2-60% by weight, based on the total weight of the catalyst.

[0293] In the present application, the catalyst is not particularly limited and can be prepared by conventional methods or obtained commercially.

[0294] In addition, in step 2), the conditions for the second contact can include a temperature of 280-420°C, and a molar ratio of hydrogen chloride to oxygen in the fluorine-removed hydrogen chloride gas 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 fluorine-removed hydrogen chloride gas of 0.5-4:1. By performing the second contact under the above conditions, the production efficiency and yield of chlorine gas can be further improved, and the conversion rate of hydrogen chloride can be improved.

[0295] In addition, in step 2) of the present application, oxygen is further introduced based on the fluorine-removed hydrogen chloride gas obtained in step 1). In industrial production, the temperature of the introduced oxygen is generally low. Therefore, in the present application, the temperature of the first contact is preferably 0-180°C higher than the temperature of the second contact. In this way, the temperature matching of steps 1) and 2) can be further optimized, and there is no need for separate heat exchange treatment, which significantly increases the operational convenience and reduces heat consumption.

[0296] According to the fourth aspect of the present application, the production of chlorine gas can be realized using hydrogen chloride gas containing fluorine-containing organic matter as raw material, and the activity of the catalyst will not be affected by the fluorine-containing organic matter, so that the production of chlorine gas can be carried out stably for a long time, and no carbon deposition will occur.

[0297] In addition, according to the fourth aspect of the present application, while the fluorine-containing organic matter is treated, a product with high added value, such as aluminum fluoride, can also be prepared at the same time. For example, the molar ratio of fluorine atoms to metal atoms in the generated metal fluoride can be 90% or more, and more preferably 95% or more, of the theoretical atomic molar ratio. Thus, not only is the problem of treating hydrogen chloride containing the fluorine-containing organic matter solved, but the preparation of a high-value metal fluoride product is also achieved, resulting in significant economic benefits.

[0298] The fifth aspect of the present application provides a method for purifying hydrogen chloride gas and co-producing metal fluoride, wherein the hydrogen chloride gas contains a fluorine-containing organic matter, and the method comprises:

[0299] 1) passing the hydrogen chloride gas through a reaction unit filled with a metal compound to perform a first reaction, obtaining fluorine-removed hydrogen chloride gas and causing part of the metal compound to generate metal fluoride,

[0300] wherein the metal compound has L acid in the presence of hydrogen chloride;

[0301] The content of the fluorine-containing organic matter in the fluorine-removed hydrogen chloride gas is 500 ppm or less, preferably 100 ppm or less, and more preferably 1 ppm or less.

[0302] The molar ratio of fluorine atoms to metal atoms in the metal fluoride is 90% or more, and more preferably 95% or more, of the theoretical atomic molar ratio.

[0303] According to a specific embodiment of the present application, a method for purifying hydrogen chloride gas and co-producing metal fluoride is provided, wherein the hydrogen chloride gas contains a fluorine-containing organic matter, and the method comprises:

[0304] 1) passing the hydrogen chloride gas through a reaction unit filled with a metal compound to perform a first reaction, obtaining fluorine-removed hydrogen chloride gas and causing part of the metal compound to generate metal fluoride, wherein the metal compound is one or more of an oxide, a hydroxide, a chloride, and a oxychloride of a metal, and is preferably one or both of an oxide and a hydroxide 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 the metal in the metal compound is preferably one or more of aluminum, chromium, and zirconium; the content of the fluorine-containing organic matter in the fluorine-removed hydrogen chloride gas is 500 ppm or less, preferably 100 ppm or less, and more preferably 1 ppm or less; and the molar ratio of fluorine atoms to metal atoms in the metal fluoride is 90% or more, and more preferably 95% or more, of the theoretical atomic molar ratio.

[0305] The inventors of the present application have further found that, in the industrial production process, if it is desired to simultaneously achieve the preparation of high-purity metal fluoride while treating fluorine-containing organic matter or purifying hydrogen chloride gas containing fluorine-containing organic matter, the hydrogen chloride gas containing fluorine-containing organic matter can be passed through at least one reaction unit filled with metal compounds to perform the first reaction, the metal compounds first contacted with the hydrogen chloride gas (fluorine-containing organic matter) continuously react with the fluorine-containing organic matter to convert into high-purity metal fluoride products, and the hydrogen chloride gas is preliminarily purified, and the metal compounds later contacted with the hydrogen chloride gas (fluorine-containing organic matter) can ensure that the residual fluorine-containing organic matter in the hydrogen chloride gas is completely reacted, thereby achieving the purification treatment of the hydrogen chloride gas, and further achieving the purpose of co-production of metal fluoride products from purified hydrogen chloride gas.

[0306] According to a preferred embodiment of the fifth aspect of the present application, the hydrogen chloride gas is used to produce chlorine gas and co-produce metal fluoride in a batch mode. In this case, the number of reaction units is not particularly limited. For example, the reaction unit can be one, but when the reaction unit is one, the reaction unit has a sufficient length (which can be achieved by using a segmented filling method of multiple metal compounds in one reaction unit, and the like). The hydrogen chloride gas is passed through the reaction unit filled with metal compounds to perform the first reaction. After a period of time, when the metal compounds at the front end of the reaction unit (the end first contacted with the hydrogen chloride gas) are converted into metal fluoride, and the gas flowing out from the rear end of the reaction unit still does not detect fluorine-containing organic matter, the passage of the hydrogen chloride gas is stopped, the generated metal fluoride is removed, and fresh metal compounds are supplemented (which can be supplemented directly at the front end of the reaction unit, and preferably supplemented at the rear end of the reaction unit, and the remaining part is sequentially moved forward), and then the passage of the hydrogen chloride gas is continued, and the above steps are repeated.

[0307] In this way, the generated metal fluoride can be sequentially removed and fresh metal compounds can be continuously supplemented in a batch mode. Through the above method, high-purity metal fluoride can be prepared while ensuring that the fluorine-containing organic matter in the hydrogen chloride gas is effectively removed.

[0308] According to another preferred embodiment of the fifth aspect of the present application, the hydrogen chloride gas is used to produce chlorine gas and co-produce metal fluoride in a continuous mode. In this case, the hydrogen chloride gas is preferably sequentially passed through two or more, preferably two to ten, and more preferably three to six reaction units filled with metal compounds to perform the first reaction. At this time, the two or more reaction units can be arranged in series.

[0309] Preferably, after the metal compound in the reaction unit through which the hydrogen chloride gas first passes generates metal fluoride (in this case, the "part of the metal compound" in the step 1 above can refer to all the metal compound in one or more reaction units through which the hydrogen chloride gas first passes among the multiple reaction units), the reaction unit is removed, and a new reaction unit filled with metal compound is added at the rear end of the reaction unit through which the hydrogen chloride gas last passes, and the process is repeated in this way.

[0310] According to another preferred embodiment of the fifth aspect of the present application, the hydrogen chloride gas is used to produce chlorine and co-produced metal fluoride in a batch or continuous operation mode, in which case the number of reaction units can be one or more (e.g., 2-10), and can be one, for example. The hydrogen chloride gas is made to pass through the reaction units filled with metal compound from bottom to top to perform the first reaction, and preferably, after the metal compound at the lower end of the reaction unit generates metal fluoride, the metal fluoride is removed from the lower end, and metal compound is preferably filled at the upper end of the reaction unit, and the process is repeated in this way.

[0311] In the present application, the reaction unit can be various reactors commonly used in the art, and more specifically, can be a fixed bed or a moving bed reactor, preferably a fixed bed catalyst.

[0312] Thus, according to the preferred embodiments described above, during the reaction of the hydrogen chloride gas with the metal compound, the part of the metal compound that first contacts the fluorine-containing organic matter can be fluorinated faster due to the higher content of the fluorine-containing organic matter it contacts, thereby producing metal fluoride with a higher degree of fluorination faster; the part of the metal compound that contacts the fluorine-containing organic matter later can still have sufficient processing capacity for the fluorine-containing organic matter due to the relatively lower degree of fluorination, thereby ensuring the removal of the fluorine-containing organic matter.

[0313] According to the fifth aspect of the present application, except for the differences in the above embodiments, other parts (e.g., the first reaction conditions) can be the same as those in the second aspect, which will not be described here.

[0314] Thus, according to the technical solution of the fifth aspect of the present application, the purification of hydrogen chloride containing fluorine-containing organic matter and the co-production of metal fluoride can be simultaneously and efficiently achieved.

[0315] In addition, according to a preferred embodiment of the fifth aspect of the present application, the metal compound is aluminum oxide and / or aluminum hydroxide, and the metal fluoride is aluminum fluoride, and more preferably, the aluminum fluoride meets the chemical composition requirements of AF-0 in GB / T 4292-2017 "Aluminum Fluoride".

[0316] The sixth aspect of the present application provides a method for producing chlorine and metal fluoride byproduct from hydrogen chloride gas containing fluorine-containing organic compounds, which comprises:

[0317] 1) subjecting the hydrogen chloride gas to a first reaction in a reaction unit filled with a metal compound to obtain fluorine-removed hydrogen chloride gas and to produce metal fluoride from part of the metal compound,

[0318] 2) subjecting the fluorine-removed hydrogen chloride gas obtained in step 1) to a second reaction with oxygen in the presence of a catalyst,

[0319] wherein the metal compound contains L acid under the action of hydrogen chloride, and the catalyst is a catalyst for producing chlorine by catalytic oxidation of hydrogen chloride,

[0320] the content of fluorine-containing organic compounds in the fluorine-removed hydrogen chloride gas is 500 ppm or less, preferably 100 ppm or less, and more preferably 1 ppm or less;

[0321] the molar ratio of fluorine atoms to metal atoms in the metal fluoride is 90% or more, and more preferably 95% or more, of the theoretical atomic molar ratio.

[0322] According to a specific embodiment of the present application, a method for producing chlorine and metal fluoride byproduct from hydrogen chloride gas containing fluorine-containing organic compounds is provided, which comprises:

[0323] 1) subjecting the hydrogen chloride gas to a first reaction in a reaction unit filled with a metal compound to obtain fluorine-removed hydrogen chloride gas and to produce metal fluoride from part of the metal compound,

[0324] 2) subjecting the fluorine-removed hydrogen chloride gas obtained in step 1) to a second reaction with oxygen in the presence of a catalyst,

[0325] wherein the metal compound is one or more of metal oxides, metal hydroxides, metal chlorides and metal oxychlorides, and preferably one or both of metal oxides and metal hydroxides; 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 the metal in the metal compound is preferably one or more of aluminum, chromium and zirconium,

[0326] the catalyst is a catalyst for producing chlorine by catalytic oxidation of hydrogen chloride, the content of fluorine-containing organic compounds in the fluorine-removed hydrogen chloride gas is 500 ppm or less, preferably 100 ppm or less, and more preferably 1 ppm or less;

[0327] the molar ratio of fluorine atoms to metal atoms in the metal fluoride is 90% or more, and more preferably 95% or more, of the theoretical atomic molar ratio.

[0328] In the method of the sixth aspect of the present application, the technical concept of the first reaction of step 1) is the same as or similar to that of the fifth aspect described above; and the second reaction of step 2) is the same as or similar to step 2) of the fourth aspect described above, which will not be described herein again.

[0329] By the method of the sixth aspect of the present application, hydrogen chloride gas can be used to produce chlorine gas while co-producing metal fluoride.

[0330] Therefore, by the technical solution of the sixth aspect of the present application, hydrogen chloride containing fluorine-containing organic matter can be used to produce chlorine gas and metal fluoride can be co-produced at the same time.

[0331] In addition, according to a preferred embodiment of the sixth aspect of the present application, the metal compound is aluminum oxide and / or aluminum hydroxide, the metal fluoride is aluminum fluoride, and more preferably, the aluminum fluoride meets the chemical composition requirements of AF-0 in GB / T 4292-2017 Aluminum Fluoride.

[0332] The present application will be described in detail below through examples, but the present application is not limited by the following examples.

[0333] In the following examples and comparative examples, the metal compound is determined by the pyridine adsorption infrared method described in the specification to determine whether it contains L acid under the action of hydrogen chloride.

[0334] Through testing, among the metal compounds used in the following examples and comparative examples, aluminum oxide, aluminum hydroxide, zirconium oxide, and chromium oxide all contain L acid under the action of hydrogen chloride, and aluminum metaphosphate, copper aluminate, and calcium oxide do not contain L acid under the action of hydrogen chloride.

[0335] In the following examples, comparative examples, and application examples, the elemental content and F spectrum of the metal fluoride are determined by an X-ray photoelectron spectrometer (XPS) of PHI Quantera II model from Japan ulvac-phi company.

[0336] In the following examples, comparative examples, and application examples, the gas chromatograph used is Agilent Lab GC 8860 gas chromatograph from Agilent Technologies.

[0337] The hydrogen chloride catalytic oxidation catalyst used in the following application examples and comparative application examples for producing chlorine is a catalyst of type SCCR-20 produced by Sinopec Catalyst Co., Ltd., wherein the content of each active component calculated as chloride, based on the total weight of the catalyst, is: copper chloride 15.0 wt%, lanthanum chloride 3.1 wt%, manganese chloride 1.8 wt%, samarium chloride 8.0 wt%, potassium chloride 3.2 wt%, and the rest is the carrier alumina.

[0338] In the following application examples and comparative application examples, the conversion rate of hydrogen chloride is determined according to the following method.

[0339] 1) Analysis method

[0340] The content of chlorine and hydrogen chloride in the gas at the outlet of the reactor is analyzed, from which the conversion rate of hydrogen chloride can be obtained.

[0341] The method for determining chlorine is the iodometric method. When chlorine is passed into a KI solution, I2 is produced, and then a standard Na2S2O3 solution is used for titration. A small amount of hydrogen chloride is also absorbed into the KI solution, and the amount of HCl is determined by using a standard NaOH solution. The specific steps are as follows:

[0342] (1) Take an appropriate amount of analysis solution in a conical flask, and add three drops of 1 wt% starch indicator. At this time, the solution is blue;

[0343] (2) After stirring, titrate with a 0.1 mol / L Na2S2O3 standard solution. During the titration process, the following chemical reaction occurs in the conical flask:

[0344] (3) I2 reacts with Na2S2O3, and the solution immediately changes from deep blue to colorless and transparent, which is the titration endpoint. Record the initial reading V1 (mL) and the final reading V2 (mL) of the burette.

[0345] I2 + 2Na2S2O3 → 2NaI + Na2S4O6

[0346] After the iodometric titration is completed, the HCl content in the KI solution is titrated by using the acid-base neutralization method with a standard NaOH solution.

[0347] (1) Add three drops of 1% phenolphthalein indicator to the conical flask after the iodometric titration is completed, and the solution remains colorless and transparent;

[0348] (2) After stirring with a glass rod, titrate with a 0.1 mol / L NaOH standard solution. During the titration process, the following chemical reaction occurs:

[0349] (3) When the solution immediately changes from colorless and transparent to light red, it is the titration endpoint. Record the initial reading V3 (mL) and the final reading V4 (mL) of the burette.

[0350] NaOH + HCl → NaCl + H2O

[0351] 2) Calculation method

[0352] According to the titration analysis data, the amount of substance of Cl2 and HCl, the conversion rate of HCl are further calculated, and the calculation formula is as follows:

[0353] The amount of substance of Cl2:

[0354] The amount of substance of HCl:

[0355] The conversion rate of HCl:

[0356] Example 1

[0357] 1.2 g of alumina with a particle size of 0.15-0.18 mm was filled in the reaction tube, and after being heated to a reaction temperature of 370℃, a mixed gas of CHF3 and HCl was continuously introduced at this temperature, wherein the concentration of CHF3 was 1% by volume, the balance was HCl gas, and the volume space velocity of the mixed gas was 1000h -1 .

[0358] After 1h of reaction, the gas products after reaction were detected at the outlet end of the reaction tube by gas chromatograph, and the gas chromatograph did not detect CHF3;

[0359] After 9h of reaction, part of the solid material in the reaction tube was taken out and analyzed by X-ray photoelectron spectrometer (XPS) for element content, and the results showed that the F content was 43.77% by weight, and the Al content was 25.47% by weight. The F spectrum showed that F existed in the form of AlF3;

[0360] After 61h of reaction, the solid material in the reaction tube was taken out and analyzed by X-ray photoelectron spectrometer (XPS) for element content, and the results showed that the F content was 61.5% by weight, and the Al content was 31.6% by weight. The quality reached the chemical composition requirements of AF-0 in GB / T 4292-2017 “Aluminum Fluoride”.

[0361] The F spectrum showed that F existed in the form of AlF3.

[0362] After 61h of reaction, the solid material in the reaction tube was taken out and analyzed by X-ray photoelectron spectrometer (XPS) for element content, and the results showed that the F content was 61.5% by weight, and the Al content was 31.6% by weight. The quality reached the chemical composition requirements of AF-0 in GB / T 4292-2017 “Aluminum Fluoride”.

[0363] In addition, it was found by observation that there was no obvious carbon deposition on the surface of the solid material.

[0364] The XPS total spectrum of the solid material obtained after 61h of reaction is shown in Figure 1, and the F spectrum is shown in Figure 2.

[0365] Example 2

[0366] The reaction tube was filled with 1.2 g of aluminum hydroxide with a particle size of 0.15-0.18 mm, and then heated to a reaction temperature of 460°C. After the temperature reached 460°C, a mixed gas of CHF3 and HCl was continuously introduced at the temperature, wherein the concentration of CHF3 was 50% by volume, the balance was HCl gas, and the volume space velocity of the mixed gas was 100 h -1 .

[0367] After 0.5 h of reaction, the gas product after reaction was detected at the outlet end of the reaction tube by a gas chromatograph, and the gas chromatograph did not detect CHF3.

[0368] After 9 h of reaction, the solid material in the reaction tube was taken out and analyzed by X-ray photoelectron spectroscopy (XPS) for elemental content, and the results showed that the F content was 61.7% by weight and the Al content was 31.6% by weight. The quality reached the chemical composition requirements of AF-0 in GB / T 4292-2017 “Aluminum Fluoride”.

[0369] The F spectrum showed that F existed in the form of AlF3.

[0370] It was calculated that the molar ratio of fluorine atoms to aluminum atoms in the obtained solid material was 92.4% of the theoretical atomic molar ratio.

[0371] In addition, it was found by observation that there was no obvious carbon deposition on the surface of the solid material.

[0372] Example 3

[0373] The reaction tube was filled with 1.2 g of zirconium dioxide with a particle size of 0.15-0.18 mm, and then heated to a reaction temperature of 500°C. After the temperature reached 500°C, a mixed gas of CHF3 and HCl was continuously introduced at the temperature, wherein the concentration of CHF3 was 50% by volume, the balance was HCl gas, and the volume space velocity of the mixed gas was 100 h -1 .

[0374] After 0.5 h of reaction, the gas product after reaction was detected at the outlet end of the reaction tube by a gas chromatograph, and the gas chromatograph did not detect CHF3.

[0375] After 20 h of reaction, the solid material in the reaction tube was taken out and analyzed by X-ray photoelectron spectroscopy (XPS) for elemental content, and the results showed that the F content was 45.2% by weight and the Zr content was 54.3% by weight.

[0376] The F spectrum showed that F existed in the form of ZrF4.

[0377] It was calculated that the molar ratio of fluorine atoms to zirconium atoms in the obtained solid material was 99.9% of the theoretical atomic molar ratio.

[0378] In addition, it is found by observation that no obvious carbon deposition is observed on the surface of the solid substance.

[0379] Example 4

[0380] The reaction tube was filled with 1.2 g of chromium oxide with a particle size of 0.15-0.18 mm, and then heated to a reaction temperature of 370°C. After the temperature reached 370°C, a mixed gas of CHF3 and HCl was continuously introduced at the reaction temperature, wherein the concentration of CHF3 was 50% by volume, and the balance was HCl gas. The volume space velocity of the mixed gas was 100 h -1 .

[0381] After 0.5 h of reaction, the gaseous products after the reaction were detected at the outlet end of the reaction tube by using a gas chromatograph, and no CHF3 was detected by the gas chromatograph.

[0382] After 20 h of reaction, the solid substance in the reaction tube was taken out, and the elemental content of the solid substance was analyzed by using an X-ray photoelectron spectrometer (XPS). The results showed that the content of F was 48.5% by weight, and the content of Cr was 45.2% by weight.

[0383] The F spectrum showed that F existed in the form of CrF3.

[0384] It was calculated that the molar ratio of fluorine atoms to chromium atoms in the obtained solid substance was 97.9% of the theoretical molar ratio of the two atoms.

[0385] In addition, it is found by observation that no obvious carbon deposition is observed on the surface of the solid substance.

[0386] It can be seen from Examples 1 to 4 that in the presence of hydrogen chloride, the metal compound described in the application can effectively remove the fluorine-containing organic compound when the amount of the metal compound is sufficient relative to the fluorine-containing organic compound; on the other hand, high-purity metal fluoride can be obtained when the amount of the fluorine-containing organic compound is sufficient.

[0387] Example 5

[0388] The method described in Example 1 was followed, except that a mixed gas of CHCl2F (fluorodichloromethane) and HCl was continuously introduced, wherein the concentration of CHCl2F was 1% by volume, and the balance was HCl.

[0389] After 1 h of reaction, the gaseous products after the reaction were detected at the outlet end of the reaction tube by using a gas chromatograph, and no CHCl2F was detected by the gas chromatograph.

[0390] After 9 h of reaction, the solid substance in the reaction tube was taken out, and the elemental content of the solid substance was analyzed by using an X-ray photoelectron spectrometer (XPS). The results showed that the content of F was 26.7% by weight, and the content of Al was 30.2% by weight.

[0391] F spectrum shows that F exists in the form of AlF3.

[0392] In addition, it is found by observation that no obvious carbon deposition is observed on the surface of the solid substance.

[0393] Example 6

[0394] The method described in Example 1 is followed, except that a mixed gas of CHClF (difluorochloromethane) and HCl is continuously passed in, wherein the concentration of CHClF is 1 vol%, and the balance is HCl.

[0395] After 9 hours of reaction, the solid substance in the reaction tube is taken out, and the elemental content thereof is analyzed by X-ray photoelectron spectrometer (XPS), and the results show that the content of F is 31.5 wt%, and the content of Al is 27.5 wt%.

[0396] After 9 hours of reaction, the solid substance in the reaction tube is taken out, and the elemental content thereof is analyzed by X-ray photoelectron spectrometer (XPS), and the results show that the content of F is 31.5 wt%, and the content of Al is 27.5 wt%.

[0397] F spectrum shows that F exists in the form of AlF3.

[0398] In addition, it is found by observation that no obvious carbon deposition is observed on the surface of the solid substance.

[0399] Example 7

[0400] The method described in Example 1 is followed, except that a mixed gas of CHClF (difluorochloromethane) and HCl is continuously passed in, wherein the concentration of CHClF is 1 vol%, and the balance is HCl.

[0401] After 9 hours of reaction, the solid substance in the reaction tube is taken out, and the elemental content thereof is analyzed by X-ray photoelectron spectrometer (XPS), and the results show that the content of F is 31.5 wt%, and the content of Al is 27.5 wt%.

[0402] After 9 hours of reaction, the solid substance in the reaction tube is taken out, and the elemental content thereof is analyzed by X-ray photoelectron spectrometer (XPS), and the results show that the content of F is 31.5 wt%, and the content of Al is 27.5 wt%.

[0403] F spectrum shows that F exists in the form of AlF3.

[0404] In addition, it is found by observation that no obvious carbon deposition is observed on the surface of the solid substance.

[0405] Example 8

[0406] The method described in Example 1 is followed, except that a mixed gas of CHClF (difluorochloromethane) and HCl is continuously passed in, wherein the concentration of CHClF is 1 vol%, and the balance is HCl.

[0407] After 1 h of reaction, the gaseous products after reaction were detected at the outlet end of the reaction tube by gas chromatograph, and the gas chromatograph did not detect CHF.

[0408] After 9 h of reaction, the solid substance in the reaction tube was taken out and analyzed for element content by X-ray photoelectron spectroscopy (XPS), and the results showed that the F content was 32.8 wt%, and the Al content was 28.91 wt%.

[0409] The F spectrum showed that F existed in the form of AlF3.

[0410] Example 9

[0411] The method described in Example 1 was followed, except that a mixed gas of C3F6 (hexafluoropropylene) and HCl was continuously introduced, wherein the concentration of C3F6 was 1 vol%, and the balance was HCl.

[0412] After 1 h of reaction, the gaseous products after reaction were detected at the outlet end of the reaction tube by gas chromatograph, and the gas chromatograph did not detect C3F6.

[0413] After 9 h of reaction, the solid substance in the reaction tube was taken out and analyzed for element content by X-ray photoelectron spectroscopy (XPS), and the results showed that the F content was 29.2 wt%, and the Al content was 28.6 wt%.

[0414] The F spectrum showed that F existed in the form of AlF3.

[0415] As can be seen from Examples 5 to 9, in the presence of hydrogen chloride, using the metal compound described in the application, when the amount of metal compound is sufficient relative to the fluorine-containing organic compound, various fluorine-containing organic compounds can be effectively removed. In addition, Examples 5 to 9 only show the results of 9 h of reaction, and if the fluorine-containing organic compound is continuously introduced for a sufficient reaction time, high-purity metal fluoride can be generated.

[0416] Example 10

[0417] The method described in Example 1 was followed, except that the reaction temperature was 330°C.

[0418] After 1 h of reaction, the gaseous products after reaction were detected at the outlet end of the reaction tube by gas chromatograph, and the gas chromatograph did not detect CHF3.

[0419] After 9 h of reaction, the solid substance in the reaction tube was taken out and analyzed for element content by X-ray photoelectron spectroscopy (XPS), and the results showed that the F content was 24.6 wt%, and the Al content was 30.1 wt%. The F spectrum showed that F existed in the form of AlF3.

[0420] In addition, it was found by observation that there was no obvious carbon deposition on the surface of the solid substance.

[0421] Comparative Example 1

[0422] The method described in Example 1 was followed, except that,

[0423] The mixture gas of CHF3and HCl was replaced by the mixture gas of CHF3and N2, i.e. CHF3was 1 vol%, and the balance was N2.

[0424] After 1 h of reaction, the gaseous product after reaction was detected at the outlet end of the reaction tube by gas chromatography, and the results showed that the content of CHF3in the gaseous product was 0.87 vol%.

[0425] After 9 h of reaction, the solid substance in the reaction tube was taken out, and the elemental content was analyzed by X-ray photoelectron spectroscopy (XPS), and the results showed that the content of F was 9.3 wt%, and the content of Al was 32.9 wt%.

[0426] The F spectrum showed that F existed in the form of AlF3.

[0427] In addition, it was found by observation that the surface of the solid substance was gray-black, and the carbon deposition was obvious.

[0428] The results showed that in the absence of HCl, the reaction degree of alumina with CHF3was low, and it was difficult to effectively remove CHF3before the alumina was completely fluorinated, and the purity of the obtained aluminum fluoride was low, and the aluminum fluoride product meeting the standard could not be prepared.

[0429] Comparative Example 2

[0430] The method described in Example 1 was followed, except that,

[0431] The alumina was replaced by calcium oxide of the same weight.

[0432] After 1 h of reaction, the gaseous product after reaction was detected at the outlet end of the reaction tube by gas chromatography, and the results showed that the content of CHF3in the gaseous product was 1 vol%.

[0433] After 9 h of reaction, the solid substance in the reaction tube was taken out, and the elemental content was analyzed by X-ray photoelectron spectroscopy (XPS), and the results showed that the content of F was 5.3 wt%, and the content of Ca was 35.8 wt%.

[0434] In addition, it was found by observation that the surface of the solid substance was gray-black, and the carbon deposition was obvious.

[0435] The results showed that in the presence of hydrogen chloride, the reaction degree of calcium oxide with CHF3was low, and it was difficult to effectively remove CHF3before the calcium oxide was completely fluorinated, and the purity of the obtained calcium fluoride was low.

[0436] Comparative Example 3

[0437] The method described in Example 1 was followed, except that

[0438] The aluminum oxide was replaced with an equal weight of aluminum phosphate.

[0439] After 1 h of reaction, the gaseous products after reaction were detected at the outlet end of the reaction tube using a gas chromatograph, and the results showed that the CHF3 content in the gaseous products was 1 vol%.

[0440] After 9 h of reaction, the solid substance in the reaction tube was removed and analyzed for elemental content using X-ray photoelectron spectroscopy (XPS), and the results showed that the F content was 0.18 wt%, and the Al content was 7.44 wt%. The F content was very low, and the F spectrum signal was weak.

[0441] In addition, it was observed that the surface of the solid substance was gray-black, and carbon deposition was obvious.

[0442] The results showed that the reaction degree of aluminum phosphate with CHF3 was low in the presence of hydrogen chloride, CHF3 was difficult to remove effectively, and it was difficult to produce aluminum fluoride.

[0443] Comparative Example 4

[0444] The method described in Example 1 was followed, except that

[0445] The aluminum oxide was replaced with an equal weight of copper aluminate.

[0446] After 1 h of reaction, the gaseous products after reaction were detected at the outlet end of the reaction tube using a gas chromatograph, and the results showed that the CHF3 content in the gaseous products was 1 vol%.

[0447] After 9 h of reaction, the solid substance in the reaction tube was removed and analyzed for elemental content using X-ray photoelectron spectroscopy (XPS), and the results showed that the F content was 0.02 wt%, the Al content was 37.04 wt%, and the Cu content was 43.59 wt%. The F content was very low, and the F spectrum signal was weak.

[0448] In addition, it was observed that the surface of the solid substance was obviously black, and carbon deposition was obvious.

[0449] The results showed that the reaction degree of copper aluminate with CHF3 was low in the presence of hydrogen chloride, CHF3 was difficult to remove, and it was difficult to produce aluminum fluoride or copper fluoride.

[0450] Application Example 1

[0451] 1) Fill 90.23 g of alumina with a particle size of 2-3 mm in a reaction tube, and heat to a reaction temperature of 370°C. After the temperature is stabilized, a mixed gas of CHF3, CHClF and HCl is introduced at the temperature, wherein the concentration of CHF3 is 0.16 vol%, the concentration of CHClF is 0.08 vol%, and the balance is HCl. The volume space velocity of the mixed gas is 240 h-1. -1 A first gas product is obtained from the outlet end of the reaction tube;

[0452] 2) The first gas product obtained in step 1) is adsorbed by a hydrogen fluoride adsorbent (SCAF-20 hydrogen fluoride adsorbent produced by Sinopec Catalyst Co., Ltd.), and then treated by a carbon monoxide treatment catalyst (SCCC-10 carbon monoxide treatment catalyst produced by Sinopec Catalyst Co., Ltd.) to remove CO, to obtain a second gas product;

[0453] 3) The second gas product obtained in step 2) (calculated by the molar amount of hydrogen chloride) and oxygen are introduced into a fixed bed reactor filled with a hydrogen chloride catalytic oxidation catalyst for producing chlorine gas at a molar ratio of 1:0.5, the reaction temperature is 370°C, the reaction pressure is 0.1 MPa, and the volume space velocity of the mixed gas (a mixture of the second gas product and oxygen) is 293 h-1. -1 .

[0454] After continuous reaction for 360 h, it is determined that the conversion rate of HCl is 90%.

[0455] After stopping the reaction and taking out the hydrogen chloride catalytic oxidation catalyst for producing chlorine gas, no carbon deposition is found on the surface of the catalyst.

[0456] As can be seen from the application example, the method provided by the present application can be used to prepare chlorine gas by using hydrogen chloride gas containing fluorine-containing organic matter as a raw material.

[0457] Comparative application example 1

[0458] The method of application example 1 is followed, except that

[0459] In step 1), the alumina is replaced by calcium oxide with the same weight and a particle size of 2-3 mm.

[0460] After continuous reaction for 40 h, it is determined that the conversion rate of HCl is reduced to 86%;

[0461] After continuous reaction for 90 h, the conversion rate of HCl is reduced to 75%, and after continuous reaction for 120 h, the conversion rate of HCl is reduced to 50%.

[0462] After stopping the reaction and taking out the catalyst, it is found that there is obvious carbon deposition on the surface of the catalyst.

[0463] Application example 2

[0464] Six same type of tubular reactors were connected in series (named as first reactor to sixth reactor according to the contact order of the mixed gas), each of which was filled with 773 kg of alumina with a particle size of 2-3 mm, and then heated to a reaction temperature of 370 ℃, and after the temperature was kept, a mixed gas of CHF3 and HCl was introduced at the temperature, wherein the concentration of CHF3 was 1.22% by volume, the rest was HCl gas, the volume space velocity of the mixed gas introduced into the first reactor was 1000 h-1, and the volume space velocity of the mixed gas introduced into the sixth reactor was 2000 h-1. -1 .

[0465] After 100 h of reaction, the gas product after reaction was detected at the outlet end of the sixth reactor by using a gas chromatograph, and no CHF3 was detected by the gas chromatograph.

[0466] After 100 h of reaction, the solid substance in the first reactor was taken out and analyzed for element content by using an X-ray photoelectron spectrometer (XPS), and the results were as follows:

[0467] The F content in the solid substance in the first reactor was 63.8% by weight, and the Al content was 30.6% by weight, which met the chemical composition requirements of AF-0 in GB / T 4292-2017 “Aluminum Fluoride”. It was calculated that the molar ratio of fluorine atoms to aluminum atoms was 98.7% of the theoretical atomic molar ratio.

[0468] In the solid substance in the first reactor, the F spectrum showed that F existed in the form of AlF3.

[0469] In addition, it was found by observation that no obvious carbon deposition was observed on the surface of the solid substance in each reactor.

[0470] As can be seen from the application example, by using the method described in the application, purification of hydrogen chloride containing fluorine-containing organic matter can be achieved in industry, and metal fluoride product can be co-produced.

[0471] Application Example 3

[0472] The reactor was set according to the method described in Application Example 2, the metal compound was filled, the mixed gas was introduced, and the reaction conditions were controlled. The difference is that,

[0473] The gas discharged from the outlet end of the sixth reactor was sequentially sent into 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 remove HF and CO;

[0474] Then, the gas (calculated by molar amount based on hydrogen chloride) removing HF, CO and oxygen is passed into the fixed bed reactor filled with the hydrogen chloride catalytic oxidation catalyst for producing chlorine at a molar ratio of 1:0.5, the reaction temperature is 380 DEG C, the reaction pressure is 0.1 MPa, the volume space velocity of the inlet gas is 293h-1, and the reaction time is 100h. -1 .

[0475] After 100h of continuous reaction, it is determined that the conversion rate of HCl is 92%.

[0476] After 100h of continuous reaction, it is determined that the composition of the gas at the outlet of the first reactor is basically the same as that of the mixed gas of CHF3 and HCl passed into the inlet, at this time, the reactor replacement operation is performed, specifically, the first reactor is removed, the aluminum fluoride product (it is tested that the F content is 63.8wt%, the Al content is 30.6wt%, and the quality meets the chemical composition requirements of AF-0 in GB / T 4292-2017 “Aluminum Fluoride”) is obtained, and a reactor filled with 773kg of alumina with a particle size of 2-3mm is connected in series at the end of the original sixth reactor, and the reaction is continued.

[0477] During the subsequent reaction process, the composition of the gas at the outlet of the new first reactor (i.e. the original second reactor) is detected, when it is basically the same as that of the mixed gas passed into the inlet, the above-mentioned reactor replacement operation is repeated, the above-mentioned steps are repeated, and the reaction is continued.

[0478] When the reaction continues to 2800h, it is determined that the conversion rate of HCl is 92% at this time.

[0479] In addition, in the corresponding first reactor, the aluminum fluoride product with a quality meeting the chemical composition requirements of AF-0 in GB / T 4292-2017 “Aluminum Fluoride” can be obtained.

[0480] After stopping the reaction and taking out the hydrogen chloride catalytic oxidation catalyst for producing chlorine, no carbon deposition phenomenon is found on the surface of the catalyst.

[0481] Therefore, it can be shown that by using the method of the present application, the production of chlorine from hydrogen chloride gas containing fluorine-containing organic matter as raw material can be realized in industry, and the metal fluoride product can be co-produced.

[0482] The preferred embodiments of the present application are described in detail above, but the present application is not limited thereto. Within the technical concept of the present application, various simple modifications can be made to the technical solutions of the present application, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be considered as disclosed by the present application, and all belong to the protection scope of the present application.

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 in the presence of hydrogen chloride contains L acid.

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

3. A method of producing a metal fluoride, 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 in the presence of hydrogen chloride contains L acid.

4. The method of any of claims 1-3, wherein, The fluorine-containing organic matter includes one or more of fluorocarbons represented by the following formula (1) or formula (2): n H x F y Cl z Formula (1); C m H o F p Cl q Formula (2); In formula (1), n is selected from an integer from 1 to 8, preferably from 1 to 3, x and z are each independently selected from an integer from 0, y is selected from an integer from 1, and x+y+z=2n+2, In formula (2), m is selected from an integer from 2 to 8, preferably from 2 to 3, o and q are each independently selected from an integer from 0, p is selected from an integer from 1, and o+p+q=2m, or o+p+q=2m-2, More preferably, the fluorine-containing organic compound is one or more of trifluoromethane, difluoromonochloromethane, monofluorodichloromethane, pentafluoromonochloroethane, difluoroethene and hexafluoropropene.

5. The method of any of claims 1-4, wherein, The metal compound is one or more of an oxide, a hydroxide, a chloride and a oxychloride of a metal, preferably an oxide and / or a hydroxide 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, more preferably one or more of aluminum, zirconium and chromium; Preferably, the metal compound is one or more of aluminum oxide, aluminum hydroxide, zirconium oxide and chromium oxide.

6. The method of any of claims 1-5, wherein, The conditions of the contact include: temperature of 50-750°C, preferably 350-500°C; volume space velocity of the mixed gas of the fluorine-containing organic matter and hydrogen chloride of 1-10000h -1 , preferably 50-1000h -1 ; Preferably, the contacting is carried out without adding water vapor; Preferably, the contacting is carried out without adding oxygen.

7. The method of claim 2, wherein, The content of hydrogen chloride in the hydrogen chloride gas is 50% by volume or more, preferably 90% by volume or more, more preferably 95% by volume or more; Preferably, the hydrogen chloride gas further contains hydrogen fluoride, and the content of hydrogen fluoride is preferably 1% by volume or less; Preferably, the method is such that the content of the fluorine-containing organic compound in the defluorinated hydrogen chloride gas is 500 ppm or less, more preferably 100 ppm or less, and further preferably 1 ppm or less.

8. The method of claim 3, wherein, The contacting is such that the molar ratio of fluorine atoms to metal atoms in the produced metal fluoride is 90% or more, more preferably 95% or more, of the theoretical molar ratio of the two.

9. The method of claim 3, wherein, The method comprises: contacting a fluorine-containing organic compound with aluminum oxide and / or aluminum hydroxide in the presence of hydrogen chloride to produce aluminum fluoride; Alternatively, the method comprises: contacting a mixture of a fluorine-containing organic compound and hydrogen chloride with aluminum oxide and / or aluminum hydroxide to produce aluminum fluoride.

10. A process for the production of chlorine gas from hydrogen chloride gas, characterized in that, The hydrogen chloride gas contains a fluorine-containing organic compound, and the method comprises: 1) contacting the hydrogen chloride gas with a metal compound to obtain a defluorinated hydrogen chloride gas and produce a metal fluoride; 2) contacting the defluorinated hydrogen chloride gas obtained in step 1) with oxygen in the presence of a catalyst, The metal compound is one or more of oxide, hydroxide, chloride and oxychloride of the metal; preferably, the metal compound is one or more of oxide and / or hydroxide of the metal.

11. The method of claim 10, wherein, The fluorine-containing organic matter includes one or more of fluorocarbons represented by the following formula (1) or formula (2): 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 selected from 1-8, preferably selected from 1-3, x and z are each independently an integer selected from 0 or above, y is an integer selected from 1 or above, and x+y+z=2n+2, In formula (2), m is an integer selected from 2-8, preferably selected from 2-3, o and q are each independently an integer selected from 0 or above, p is an integer selected from 1 or above, and o+p+q=2m, or o+p+q=2m, More preferably, the fluorine-containing organic matter is one or more of trifluoromethane, difluoromonochloromethane, monofluorodichloromethane, pentafluoromonochloroethane, difluoroethene and hexafluoropropene; Preferably, the content of fluorine-containing organic matter in the hydrogen chloride gas is 10% by volume or less, more preferably 5% by volume or less.

12. The method of claim 10 or 11, wherein, The metal compound is one or more of oxide, hydroxide, chloride and oxychloride of the metal; preferably, the metal compound is one or more of oxide and / or hydroxide of the 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, more preferably one or more of aluminum, zirconium and chromium; Preferably, the metal compound is one or more of aluminum oxide, aluminum hydroxide, zirconium oxide and chromium oxide.

13. The method of any of claims 10-12, wherein, In step 1), the first contact is such that the content of fluorine-containing organic matter in the obtained fluorine-removed hydrogen chloride gas is 500 ppm or less, preferably 100 ppm or less, more preferably 1 ppm or less; Preferably, the conditions of the first contacting include: a temperature of 50-750°C, preferably 360-460°C; a volume hourly space velocity of the hydrogen chloride gas of 1-10000 h -1 , preferably 50-1000 h -1 . Preferably, the first contact is carried out without adding water vapor; Preferably, the first contact is carried out without adding oxygen; Preferably, in step 2), the conditions of the second contact include: the temperature is 280-420°C, preferably 320-390°C; the molar ratio of hydrogen chloride to oxygen in the fluorine-removed hydrogen chloride gas is 0.25-10:1, preferably 0.5-4:1; Preferably, the temperature of the first contact is 0-180°C higher than the temperature of the second contact.

14. The method of any of claims 10-13, wherein, Step 1) further comprises: a step of subjecting the gas product obtained from the first contact to HF removal treatment to obtain a fluorine-removed hydrogen chloride gas; and / or a step of subjecting the gas product obtained after the first contact to CO removal treatment to obtain a fluorine-removed hydrogen chloride gas.

15. A process for purifying hydrogen chloride gas coproducting metal fluoride, characterized by, The hydrogen chloride gas contains fluorine-containing organic matter, and the method comprises: 1) subjecting the hydrogen chloride gas to first reaction by passing through one or more reaction units filled with a metal compound to obtain a fluorine-removed hydrogen chloride gas, and allowing part of the metal compound to generate a metal fluoride, The metal compound is one or more of oxide, hydroxide, chloride and oxychloride of the metal; preferably, the metal compound is one or more of oxide and / or hydroxide of the metal; The content of fluorine-containing organic matter in the fluorine-removed hydrogen chloride gas is 500 ppm or less, preferably 100 ppm or less, more preferably 1 ppm or less; The molar ratio of fluorine atoms to metal atoms in the metal fluoride is 90% or more, more preferably 95% or more, of the theoretical atomic molar ratio.

16. A process for the production of chlorine gas coproduct metal fluoride from hydrogen chloride gas, characterized by, The hydrogen chloride gas contains fluorine-containing organic matter, and the method comprises: 1) subjecting the hydrogen chloride gas to a first reaction in a reaction unit packed with a metal compound to obtain a defluorinated hydrogen chloride gas and to cause part of the metal compound to generate a metal fluoride, 2) subjecting the defluorinated hydrogen chloride gas obtained in step 1) to a second reaction with oxygen in the presence of a catalyst, wherein the metal compound in the presence of L acid under the action of hydrogen chloride, and the catalyst is a hydrogen chloride catalytic oxidation catalyst for preparing chlorine gas, the content of the fluorine-containing organic substance in the defluorinated hydrogen chloride gas is 500 ppm or less, preferably 100 ppm or less, and more preferably 1 ppm or less; the molar ratio of fluorine atoms to metal atoms in the metal fluoride is 90% or more, and more preferably 95% or more, of the theoretical molar ratio of the atoms.

17. The method of claim 15 or 16, wherein, In step 1), the hydrogen chloride gas is sequentially passed through 2 or more, preferably 2 to 10, and more preferably 3 to 6 reaction units packed with a metal compound to perform the first reaction; Preferably, after the metal compound in the reaction unit through which the hydrogen chloride gas is first passed generates a metal fluoride, the reaction unit is removed, and a reaction unit packed with a metal compound is preferably added at the rear end of the reaction unit through which the hydrogen chloride gas is last passed.

18. The method of claim 15 or 16, wherein, In step 1), the hydrogen chloride gas is passed from the bottom to the top through the reaction unit packed with a metal compound to perform the first reaction; Preferably, after the metal compound at the lower end of the reaction unit generates a metal fluoride, the metal fluoride is removed from the lower end, and a metal compound is preferably packed at the upper end of the reaction unit.

19. The method of any of claims 15-18, wherein, The fluorine-containing organic matter includes one or more of fluorocarbons represented by the following formula (1) or formula (2): 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 selected from 1 to 8, preferably from 1 to 3, x and z are each independently 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 selected from 2 to 8, preferably from 2 to 3, o and q are each independently an integer of 0 or more, p is an integer of 1 or more, and o+p+q=2m, or o+p+q=2m-2, More preferably, the fluorine-containing organic substance is one or more of trifluoromethane, difluoromonochloromethane, monofluorodichloromethane, pentafluoromonochloroethane, difluoroethene, and hexafluoropropene; Preferably, the content of hydrogen chloride in the hydrogen chloride gas is 50% by volume or more, preferably 90% by volume or more, and more preferably 95% by volume or more; Preferably, the hydrogen chloride gas containing a fluorine-containing organic substance further contains hydrogen fluoride, and the content of hydrogen fluoride is preferably 1% by volume or less.

20. The method of any of claims 15-19, wherein, The metal compound is one or more of an oxide, a hydroxide, a chloride, and an oxychloride of a metal; and is preferably an oxide and / or a hydroxide 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 is one or more of aluminum, zirconium, and chromium; Preferably, the metal compound is one or more of aluminum oxide, aluminum hydroxide, zirconium oxide, and chromium oxide, and more preferably is aluminum oxide and / or aluminum hydroxide.

21. The method of any of claims 15-20, wherein, In the first reaction of step 1), the conditions include: temperature of 50-750°C, preferably 360-460°C; volume space velocity of the hydrogen chloride gas of 1-10000h -1 , preferably 50-1000h -1 ; Preferably, the first reaction is performed without adding water vapor; Preferably, the first reaction is performed without adding oxygen.

22. The method of any of claims 15-21, wherein, Step 1) further comprises: a step of treating the gaseous product of the first reaction to remove HF to obtain a gaseous product of which the fluorine-containing hydrogen chloride is removed; and / or Step 1) further comprises: a step of treating the gaseous product of the first reaction to remove CO to obtain a gaseous product of which the fluorine-containing hydrogen chloride is removed.

23. The method of claim 16, wherein, In Step 2), the conditions of the second reaction comprise: a temperature of 280-420°C, preferably 320-390°C; and a molar ratio of hydrogen chloride to oxygen in the gaseous product of which the fluorine-containing hydrogen chloride is removed is 0.25-10:1, preferably 0.5-4:

1. Preferably, the temperature of the first reaction is 0-180°C higher than the temperature of the second reaction.

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