Method for resource utilization of fluorine-containing waste gas in production of hexafluoropropylene oxide and co-production of hydrofluoroether

Abstract

The invention discloses a method for resource utilization of fluorine-containing waste gas in hexafluoropropylene oxide production and co-production of hydrofluoroether, which comprises the following steps of: firstly, reacting the fluorine-containing waste gas in hexafluoropropylene oxide production under the action of a fluorine ion catalytic system to generate a perfluorinated intermediate product; then, the perfluorinated intermediate product reacts with an alkylating reagent under the action of a fluorinating reagent to produce a hydrofluoroether product. Hydrofluoroether products with different structures are obtained by utilizing the characteristics of nucleophilic addition reaction of a by-product acyl fluoride and hexafluoropropylene in the production of hexafluoropropylene oxide and utilizing the characteristics of the addition product for preparing hydrofluoroether by using the same alkylation process; the hydrofluoroether products are widely applied to the fields of semiconductor temperature control fluid, data center immersion heat exchange fluid, electrified cleaning agents and inert diluents of base stations or weak current equipment and the like, and have high added value.

Description

Technical Field

[0001] The invention belongs to the technical field of fluorine chemical industry, and specifically relates to a technology for resource utilization of fluorine-containing waste gas produced by hexafluoropropylene oxide. Background Art

[0002] Hexafluoropropylene oxide (HFPO) is an important fluorine-containing fine chemical and an important fluorine-containing organic intermediate for the production of perfluoropolyether oil, hexafluoroacetone, hexafluoroisopropanol and fluorine-containing surfactants. Since HFPO has high chemical activity and can react with various nucleophilic reagents, it can produce various perfluoroalkyl vinyl ethers. Perfluoroalkyl vinyl ethers can be used as comonomers or modified monomers to participate in polymerization reactions and are used in the production of melt-processable fluororesins, fluororubbers and fluoropolymers with functional groups, thereby changing the properties of difficult-to-process fluororesins such as polytetrafluoroethylene, and its market demand has developed rapidly.

[0003] At present, the production of hexafluoropropylene oxide in industry is mainly based on hexafluoropropylene as raw material, and adopts molecular oxygen liquid phase method to react at high temperature to obtain, and it is inevitable to produce a large amount of waste gas containing carbonyl fluoride and acetyl fluoride in the reaction process, and this waste gas accounts for 10~30% of the total production as by-product, wherein this waste gas contains 10~50% carbonyl fluoride (CF2O), 10~70% acetyl fluoride (CF3CFO), and there are other fluorine-containing waste gas etc., and this waste gas also has corresponding change because of the different control of production. This waste gas generally adopts water washing and alkali liquor absorption to process, and produces the aqueous hydrofluoric acid with low production value, and is also accompanied by the generation of a large amount of waste water, and can cause waste of resources. Therefore, it is very necessary to fully and reasonably utilize the waste gas by-products such as carbonyl fluoride in production to produce products with utilization value, which can greatly reduce the production cost of perfluoropolyether, and also save the water and alkaline substances consumed by these by-products, and also avoid the trouble of comprehensive discharge wastewater treatment.

[0004] For example, patent CN101817728A discloses a method for producing hexafluoropropylene oxide and co-producing perfluorovinyl ether, comprising introducing hexafluoropropylene oxide into a mixed gas by-product of carbonyl fluoride and perfluoroacetyl fluoride produced during the oxidation of hexafluoropropylene to synthesize hexafluoropropylene oxide, carrying out a polymerization reaction to obtain a corresponding perfluoropolyether mixture, and then subjecting the mixture to a cracking reaction to obtain a perfluorovinyl ether mixture.

[0005] For example, patent CN109678700A discloses a method for preparing byproducts generated in HFPO by comprehensive utilization of oxygen oxidation method, using ultraviolet light to irradiate fluoride solvent to obtain carbonyl fluoride, an important chemical intermediate in fluorine chemical industry, and converting the byproducts into perfluorinated surfactants or fluorine-containing fluids.

[0006] Hydrofluoroether has an ozone depletion potential (ODP) of 0, a low greenhouse effect potential (GWP), and a short residence time in the atmosphere, with almost no impact on the environment. It is an ideal replacement product for the new generation of green and environmentally friendly ODS. Hydrofluoroether is an important fluorine-containing chemical. It has good electrical insulation and environmental performance, low surface tension, low viscosity, low toxicity, high KB value and other advantages, and is widely used in electronic cleaning agents, solvents, lubricant deposition agents and other fields.

[0007] There are many synthetic methods for preparing hydrofluoroethers, such as: acyl fluoride monomer methylation method, 3M company patent CN1177374A disclosed technical solution, under the condition of N, N dimethylformamide solvent, isobutyryl fluoride as raw material, and reacts with metal fluoride and alkylating agent for 16 hours to obtain nonafluoroisobutyl methyl ether, and reacts for 72 hours to obtain nonafluoroisobutyl ethyl ether. This method has been industrialized. However, due to the high cost of preparing acyl fluoride monomers, and the raw material uses HF, which has high requirements for equipment; the main method for preparing perfluorobutyryl fluoride in industry at present is through electrolytic fluorination, using butyryl chloride as raw material to prepare perfluorobutyryl fluoride by electrolytic fluorination. The technical solution disclosed in US6013795A uses electrolysis to prepare perfluorobutyryl fluoride, and the electrolytic efficiency is very low. And because the degree of electrolysis is difficult to control, the purity of the target product perfluorobutyryl fluoride is low and there are many impurities. At the same time, the production price of electrode plates in electrolytic equipment is expensive. The technical solution disclosed in US3351644 uses perfluoroiodide to react with fuming and concentrated sulfuric acid to prepare perfluoroacyl compounds. However, this method has harsh reaction conditions, difficult to obtain raw materials, high equipment requirements, and high operating risks. Therefore, it is not suitable for industrial scale-up production.

[0008] Chinese patent CN109503366B discloses that hexafluoropropylene dimer is used as raw material, and is cracked at high temperature by catalytic oxidation to obtain perfluoroisobutyryl fluoride, which is then reacted with an alkylating agent to obtain perfluoroisobutyl methyl ether. The method is complex, and the catalytic oxidation method has disadvantages such as high cracking temperature, easy to produce carbon deposition, and short catalyst life.

[0009] U.S. Patent No. 5,750,797A proposes to use perfluoroketone as a raw material, and react with an alkylating agent in a suitable solvent system to synthesize a corresponding hydrofluoroether product. In the embodiment part, perfluorohexanone is used as a raw material, diethylene glycol dimethyl ether is used as a solvent, potassium fluoride and a phase transfer catalyst are added, and then reacted with a methylating agent dimethyl sulfate at room temperature to obtain an isolated hydrofluoroether 1,1,2,2,3,4,5,5,5 decafluoro-3-methoxy-4(trifluoromethyl)pentane. The embodiment shows that the reaction yield of this reaction method can reach about 87%, but the reaction cycle is long (more than 24 hours) and the production efficiency is low. Summary of the invention

[0010] In view of the defects of the prior art, the present invention provides a method for resource utilization of fluorine-containing waste gas in the production of hexafluoropropylene oxide and co-production of hydrofluoroether. On the one hand, the fluorine-containing waste gas in the production of hexafluoropropylene oxide is utilized as a resource, and on the other hand, the problems of high cost and low production efficiency of producing hydrofluoroether products in the prior art are solved.

[0011] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0012] A method for producing hydrofluoroether from fluorine-containing waste gas in the production of hexafluoropropylene oxide comprises the following steps: first, reacting the fluorine-containing waste gas in the production of hexafluoropropylene oxide under the action of a fluorine ion catalyst system to generate a perfluoro intermediate product; then, reacting the perfluoro intermediate product with an alkylating agent under the action of a fluorinating agent to produce a hydrofluoroether product.

[0013] Preferably, the reaction of the fluorine-containing waste gas under the action of the fluorine ion catalyst system to generate a perfluorinated intermediate product comprises the following steps:

[0014] adding a fluoride ion catalyst solution into the tower reaction system;

[0015] Then, the fluorine-containing waste gas or hexafluoropropylene is introduced into the tower reaction system for continuous reaction, the reaction temperature is maintained at 20-100° C., the reaction is carried out for 3-12 hours, the reaction product is separated into layers in a liquid separation tank, and the intermediate product in the lower layer is distilled to obtain a perfluorinated intermediate product;

[0016] Alternatively, before introducing the fluorine-containing waste gas into the tower reaction system or simultaneously introducing hexafluoropropylene for continuous reaction, part of the fluorine-containing waste gas is introduced into the reaction system, and the reaction temperature is maintained at -20 to 50°C. This part of the fluorine-containing waste gas is fully contacted with the circulating fluoride ion solution catalyst to react and form an activated intermediate.

[0017] Preferably, the preparation method of the fluoride ion catalyst solution is: the metal fluoride salt, the organic solvent and the auxiliary agent are stirred and dissolved at 50°C to 200°C, and then the fluorine-containing gas is introduced after the temperature is cooled to room temperature, and the reaction pressure is gradually reduced to equilibrium, and the activation of the catalyst system is completed to obtain the fluoride ion catalyst solution.

[0018] Preferably, the metal fluoride salt is at least one of rubidium fluoride, cesium fluoride, potassium fluoride, sodium fluoride, silver fluoride, barium fluoride and ammonium fluoride; and / or, the auxiliary agent includes a quaternary ammonium salt, a metal carboxyl compound, a cryptate; and / or, the organic solvent is at least one of adiponitrile, acetonitrile, tetrahydrofuran, diethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, N,N-dimethylformamide, dimethyl sulfoxide, 1,3-dimethyl-2-imidazolidinone and cyclopentane sulfone; and / or, the molar ratio of the metal fluoride salt to the auxiliary agent is 1:1.

[0019] Preferably, the quaternary ammonium salt includes tetrabutylammonium bromide, 464 reagent, dodecylmethylbenzylammonium bromide, octadecyltrimethylammonium iodide; and / or, the cryptate includes 15-crown-5, 18-crown-6, 18-diazacrown-6, 21-crown-7, 24-crown-8.

[0020] Preferably, when the fluorine-containing waste gas or hexafluoropropylene is introduced into the tower reaction system for continuous reaction, the molar ratio of the fluorine ion catalyst to the fluorine-containing waste gas is 0.01-0.5:1, and the molar ratio of the fluorine-containing waste gas to hexafluoropropylene is 1-1.5:1.

[0021] Preferably, the perfluorinated intermediate product reacts with an alkylating agent under the action of a fluorinating agent to produce a hydrofluoroether, comprising the following steps:

[0022] The intermediate product and the fluorination agent are introduced into the alkylation reactor and stirred to combine;

[0023] An alkylation agent is added to the alkylation reactor, the reaction temperature is maintained at 20 to 150° C., and the reaction is carried out for 3 to 72 hours; the lower layer mixture product in the alkylation reactor is treated and enters a distillation system to obtain a hydrofluoroether product.

[0024] Preferably, the perfluorinated intermediate product includes perfluoropropionyl fluoride, perfluoro-2-methyl-propionyl fluoride, perfluoro-3-methyl-2-butanone, perfluoro-2-methyl-3-pentanone, perfluoro-2-methoxy-propionyl fluoride, and perfluoro-2-ethoxy-propionyl fluoride; and / or, the fluorination reagent is prepared from a fluoride salt, an additive, and an anhydrous non-protonic polar solvent; and / or, the alkylating agent includes trifluoroethyl trifluoromethanesulfonate, methyl trifluoromethanesulfonate, ethyl trifluoromethanesulfonate, dimethyl sulfate, diethyl sulfate, dimethyl carbonate, and diethyl carbonate.

[0025] Preferably, the fluoride salt is at least one of potassium fluoride, sodium fluoride, barium fluoride, silver fluoride and ammonium fluoride, and the molar ratio of the fluoride salt to the perfluorinated intermediate product is 1 to 2:1; and / or the additive includes tetrabutylammonium bromide, At least one of 464 reagent, dodecylmethylbenzylammonium bromide, octadecyltrimethylammonium iodide, 18-crown ether-6, 15-crown ether-5, and tetramethylethylenediamine; and / or the anhydrous aprotic polar solvent is a mixed solvent, which is a mixture of hexamethylphosphoric triamide and any one or more of adiponitrile, acetonitrile, N,N-dimethylformamide, dimethyl sulfoxide, 1,3-dimethyl-2-imidazolidinone and cyclopentane sulfone, and the mass percentage of hexamethylphosphoric triamide in the mixed solvent is 1 to 99%.

[0026] Preferably, the crude hexafluoropropylene oxide product is produced through the top component of a light-removing tower and sent to a deoxygenation tower to obtain the fluorine-containing waste gas; and / or the fluorine-containing waste gas includes hexafluoropropylene, hexafluoropropylene oxide, formyl fluoride, perfluoroacetyl fluoride and perfluoropropionyl fluoride, wherein the total content of formyl fluoride and perfluoroacetyl fluoride accounts for 30% to 99.5%.

[0027] Preferably, the hydrofluoroether has the following molecular formula, wherein Me=CH3, CH2CH3, CH2CF3:

[0028]

[0029] The hydrofluoroethers include 1,1,1,2,2,3,3-heptafluoropropyl methyl ether, 1,1,1,2,2,3,3-heptafluoropropyl ethyl ether, 1,1,1,2,2,3,3-heptafluoropropyl trifluoroethyl ether, 2-trifluoromethyl-1,1,1,2,3,3-hexafluoropropyl methyl ether, 2-trifluoromethyl-1,1,1,2,3,3-hexafluoropropyl ethyl ether, 2-trifluoromethyl-1,1,1,2,3,3-hexafluoropropyl 1,1,2,3,3-hexafluoropropyl trifluoroethyl ether, 2,3-bis(trifluoromethyl)-1,1,1,2,3,-pentafluoropropyl methyl ether, 2,3-bis(trifluoromethyl)-1,1,1,2,3,-pentafluoropropyl ethyl ether, 2,3-bis(trifluoromethyl)-1,1,1,2,3,-pentafluoropropyl trifluoroethyl ether, 2-trifluoromethyl-3-methoxy-1,1,1,2,3 ,4,4,5,5,5-pentafluoropentane, 2-trifluoromethyl-3-ethoxy-1,1,1,2,3,4,4,5,5,5-pentafluoropentane, 2-trifluoromethyl-3-(1,1,1-trifluoroethoxy)-1,1,1,2,3,4,4,5,5,5-pentafluoropentane, 2-trifluoromethoxy-1,1,1,2,3,3-hexafluoropropyl methyl ether, 1,1,1,2,3,3-hexafluoropropyl ethyl ether, 2-trifluoromethoxy-1,1,1,2,3,3-hexafluoropropyl trifluoroethyl ether, 2-pentafluoroethoxy-1,1,1,2,3,3-hexafluoropropyl methyl ether, 2-pentafluoroethoxy-1,1,1,2,3,3-hexafluoropropyl ethyl ether, 2-pentafluoroethoxy-1,1,1,2,3,3-hexafluoropropyl trifluoroethyl ether.

[0030] Preferably, the tower reaction system includes a catalyst circulation pump, a main reactor connected to the circulation pump, a liquid phase separation tank connected to the main reactor, and a catalyst synthesis kettle connected to the liquid phase separation tank. The catalyst circulates continuously during the entire reaction process under the action of the circulation pump; the main reactor is a countercurrent reactor or a liquid flow contact reactor, including a spray tower reactor, a packed tower reactor, a plate tower reactor, a bubbling reactor, and a tubular reactor.

[0031] The technical solution adopted by the present invention is to utilize the mixed gas byproduct containing carbonyl fluoride and perfluoroacetyl fluoride and other products generated in the process of synthesizing hexafluoropropylene oxide by oxidation of hexafluoropropylene as resources, which has the following beneficial effects compared with the prior art:

[0032] 1. The process of producing hydrofluoroether products is combined with the resource utilization of mixed gas by-products, providing a method for producing hexafluoropropylene oxide while utilizing fluorine-containing waste gas resources and co-producing hydrofluoroethers, so that the inevitable by-products in the process of producing hexafluoropropylene oxide by high-temperature oxidation of hexafluoropropylene no longer need to be washed and discharged, causing the cost of sewage treatment and the risk of sewage leakage, but the by-products are further reacted to synthesize corresponding high-value-added hydrofluoroether products. This method not only achieves the purpose of producing hexafluoropropylene oxide, but also makes full use of the high-value-added products produced by the reaction of fluorine-containing waste gas resources, thereby making the process more reasonable, the flow more optimized, and the industrialization more economical.

[0033] 2. The key to the production method of hydrofluoroether by-producted from the mixed gas obtained from the production of hexafluoropropylene oxide is to utilize the characteristics of the nucleophilic addition reaction of the by-product acyl fluoride and hexafluoropropylene, and the characteristics of the addition product for preparing hydrofluoroether by the same alkylation process, so as to obtain hydrofluoroether products with different structures. These hydrofluoroether products are widely used in the fields of semiconductor temperature control fluids, data center immersion heat exchange fluids, base stations or live cleaning agents and inert diluents for weak current equipment, and have high added value.

[0034] The specific technical solutions and beneficial effects of the present invention will be described in detail in the following specific embodiments in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments:

[0036] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0038] According to the existing synthesis technology of hexafluoropropylene oxide: the production of hexafluoropropylene oxide in industry mainly uses hexafluoropropylene as raw material, and adopts molecular oxygen liquid phase method to react hexafluoropropylene with oxygen under certain temperature, pressure and inert solvent to obtain, and it is inevitable to produce a large amount of waste gas containing carbonyl fluoride and acetyl fluoride during the reaction process. The waste gas accounts for 10-30% of the total production as a by-product. Therefore, the product mixed gas includes the product hexafluoropropylene oxide, the by-product carbonyl fluoride, perfluoroacetyl fluoride, perfluoropropionyl fluoride and the mixed gas of unreacted hexafluoropropylene and oxygen, and the equation is as follows:

[0039] Main reaction:

[0040]

[0041] Side effects:

[0042]

[0043] The product mixed gas obtained from the hexafluoropropylene oxide production reactor is sent to a light-removal tower, and most of the heavy components hexafluoropropylene oxide, hexafluoropropylene and entrained solvents are collected and sent to an extraction distillation system to obtain high-purity hexafluoropropylene oxide. The top of the tower contains light components such as oxygen, formyl fluoride, acetyl fluoride, etc., which are also called fluorine-containing waste gas.

[0044] Since the by-products of hexafluoropropylene oxide production are inevitable, it is very necessary to make full and reasonable use of the by-products with utilization value in the reaction. This can greatly reduce the production cost of synthesizing hexafluoropropylene oxide, save the water and alkaline substances consumed in treating these by-products, and avoid the trouble of comprehensive wastewater treatment, thus creating value while avoiding pollution and waste caused by emissions.

[0045] In order to recycle the fluorine-containing waste gas in the production of hexafluoropropylene oxide and solve the problems of high cost and low production efficiency of hydrofluoroether products in the prior art, the present invention provides a method for recycle the mixed gas byproduct of carbonyl fluoride and perfluoroacetyl fluoride produced in the process of synthesizing hexafluoropropylene oxide by oxidation of hexafluoropropylene to produce hydrofluoroether.

[0046] like Figure 1 As shown, the method for producing hexafluoropropylene oxide with fluorine-containing waste gas and co-producing hydrofluoroether of the present invention comprises: firstly, reacting the fluorine-containing waste gas in the production of hexafluoropropylene oxide under the action of a fluorine ion catalyst system to generate a perfluorinated intermediate product, or, simultaneously, introducing hexafluoropropylene to react and produce an intermediate product.

[0047] Here, whether hexafluoropropylene is introduced or not is related to the composition of the mixed gas. When the mixed waste gas to be treated contains a small amount of hexafluoropropylene or hexafluoropropylene oxide, hexafluoropropylene needs to be introduced to participate in the reaction; when the mixed gas to be treated contains hexafluoropropylene and hexafluoropropylene oxide, and the content is relatively high (for example, greater than 50%, which can also be adjusted as needed), hexafluoropropylene is not introduced, and the hexafluoropropylene or hexafluoropropylene oxide contained in the gas itself participates in the reaction. Regardless of whether hexafluoropropylene is introduced or not, the intermediate obtained is the same, but the content of the intermediate will be different.

[0048] Then, in the alkylation reactor, the perfluorinated intermediate product reacts with the alkylation agent under the action of the fluorination agent to produce hydrofluoroether products. The lower layer mixture product in the alkylation reactor can be washed with alkali, washed with water, and distilled to obtain hydrofluoroethers of different structures, the molecular formula of which is as follows, wherein Me = CH3, CH2CH3, CH2CF3:

[0049]

[0050] It is understandable that the content of each component in the mixed gas is different due to the selection of different catalyst systems or different temperature pressures or solvents, and the ratio of each mixed gas is not limited. This is because in the mixed gas raw materials required for the co-production of hydrofluoroether, there is no special requirement for whether the light-removing tower completely separates hexafluoropropylene oxide and hexafluoropropylene, because both hexafluoropropylene oxide and hexafluoropropylene can continue to participate in the reaction as raw materials. Therefore, in the mixed gas at the top of the light-removing tower, in addition to formyl fluoride, acetyl fluoride and oxygen, it is completely allowed to carry a certain amount of heptafluoropropionyl fluoride, hexafluoropropylene oxide, and hexafluoropropylene. In addition, since the boiling point of oxygen is -183°C, it is easy to remove oxygen in the deoxygenation tower to obtain a mixed gas mainly composed of formyl fluoride and acetyl fluoride. The mixed gas obtained from the deoxidation tower contains 10-50% carbonyl fluoride (CF2O), 10-70% acetyl fluoride (CF3CFO), and other fluorine-containing waste gases such as hexafluoropropylene oxide and hexafluoropropylene. The content of the waste gas will also change accordingly due to different production and distillation control. Generally speaking, the mixed gas raw materials include formyl fluoride, acetyl fluoride, hexafluoropropylene, hexafluoropropylene oxide, and perfluoropropionyl fluoride, of which the total content of formyl fluoride and trifluoroacetyl fluoride accounts for 20-99.5%.

[0051] The above-mentioned intermediate products include perfluoropropionyl fluoride, perfluoro-2-methyl-propionyl fluoride, perfluoro-3-methyl-2-butanone, perfluoro-2-methyl-3-pentanone, perfluoro-2-methoxy-propionyl fluoride, and perfluoro-2-ethoxy-propionyl fluoride.

[0052] When hexafluoropropylene is introduced at the same time to react and produce the intermediate product, the above hexafluoropropylene is in gaseous or liquid state, preferably in gaseous state, to prevent the addition of excessive hexafluoropropylene and reduce the generation of by-products.

[0053] Furthermore, the above-mentioned hexafluoropropylene can come from the hexafluoropropylene recovered from the decomposition tower of the hexafluoropropylene oxidation device or the by-product hexafluoropropylene recovered from the tetrafluoroethylene device or purchased from the market. The hexafluoropropylene recovered from the decomposition tower of the hexafluoropropylene oxidation device is preferred, so as to realize the closed loop of raw material use of the entire device, and also avoid the impact of unqualified recovered hexafluoropropylene on production.

[0054] The above-mentioned reaction process is all carried out in an anhydrous system, such as a tower reaction system, and its reaction process can be produced continuously or intermittently. With reference to the prior art, the above-mentioned tower reaction system includes a catalyst circulation pump, a main reactor connected to the circulation pump, a liquid phase separation tank (or a separator) connected to the main reactor, and a catalyst synthesis reactor (or catalyst preparation tank) connected to the liquid phase separation tank, and the catalyst in the whole reaction process is continuously circulated under the action of the pump. The reactor is a convection reactor or a liquid flow contact reactor, including a spray tower reactor, a packed tower reactor, a plate tower reactor, a bubbling reactor, a tubular reactor, etc. In addition, for other gas-liquid mixing reactors, such as intermittent reactors, micro-pipeline reactors are also applicable. The preferred spray tower reactor of the present invention.

[0055] Furthermore, the spray tower reaction system includes a catalyst spray tower, a reaction packing tower connected to the spray tower, a liquid phase separation tank connected to the reaction packing tower, a catalyst circulation pump and a catalyst synthesis kettle connected to the liquid phase separation tank, and the catalyst continuously circulates and reacts under the action of the pump during the entire reaction process. The advantage of this reaction system is that the products produced by the reaction can quickly leave the area and be separated in the liquid separation tank, avoiding the production products from further participating in the reaction and causing more by-products to be produced. In addition, the catalyst is continuously recycled to avoid contact with air, and the catalyst can achieve a longer life span.

[0056] Specifically, the reaction of fluorine-containing waste gas under the action of fluorine ion catalyst system to generate perfluorinated intermediate products includes the following steps:

[0057] adding a fluoride ion catalyst solution into the tower reaction system;

[0058] Then, the fluorine-containing waste gas or hexafluoropropylene is introduced into the tower reaction system for continuous reaction, the reaction temperature is maintained at 20-100° C., the reaction is carried out for 3-12 hours, the reaction product is separated into layers in a liquid separation tank, and the intermediate product in the lower layer is distilled to obtain a perfluorinated intermediate product;

[0059] Before introducing fluorine-containing waste gas into the tower reaction system or introducing hexafluoropropylene at the same time for continuous reaction, part of the fluorine-containing waste gas is introduced into the reaction system, and the reaction temperature is maintained at -20 to 50°C. This part of the fluorine-containing waste gas is fully contacted with the circulating fluoride ion solution catalyst to react and form an activated intermediate.

[0060] When the mixed gas and hexafluoropropylene are introduced simultaneously, the mixed gas needs to be introduced into the reaction system in advance, and the introduced amount accounts for 1-20% of the mass ratio of the mixed gas, and then the mixed gas and hexafluoropropylene are introduced simultaneously at a certain molar ratio.

[0061] If only mixed gas is used as raw material, there is no need to pass a portion of it in advance, but it can be directly introduced into the reaction.

[0062] The preparation method of the fluoride ion catalyst solution is as follows: anhydrous metal fluoride salt, organic solvent and co-solvent are stirred and dissolved at 50°C to 200°C, then the temperature is lowered to room temperature, a certain amount of fluorine-containing gas is introduced, and the reaction pressure is gradually reduced to equilibrium, the catalytic system is activated, and the fluoride ion catalyst solution is obtained.

[0063] Optionally, the metal fluoride includes at least one of rubidium fluoride, cesium fluoride, potassium fluoride, sodium fluoride, silver fluoride, barium fluoride, ammonium fluoride, etc.; the auxiliary agent includes a quaternary ammonium salt, a metal carboxyl compound, a cryptate, wherein the quaternary ammonium salt includes tetrabutylammonium bromide, 464 reagent, dodecylmethylbenzylammonium bromide, octadecyltrimethylammonium iodide; the cryptates include 15-crown-5, 18-crown-6, 18-diazacrown-6, 21-crown-7, 24-crown-8; the organic solvent includes at least one of adiponitrile, acetonitrile, tetrahydrofuran, diethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, N,N-dimethylformamide, dimethyl sulfoxide, 1,3-dimethyl-2-imidazolidinone, and cyclopentane sulfone; the fluorine-containing gas consists of formyl fluoride and acetyl fluoride, wherein the content of formyl fluoride is 0 to 100%.

[0064] Optionally, in the fluoride ion catalyst solution, the molar ratio of fluoride to auxiliary agent is 1:1; the molar ratio of fluoride ion catalyst to mixed gas in the fluoride ion catalyst solution is 0.01-0.5:1; and the molar ratio of mixed gas to hexafluoropropylene is 1-1.5:1.

[0065] For the alkylation reaction, the intermediate product and the fluorination agent are introduced into the alkylation reactor and stirred for a period of time; then the alkylation agent is added into the reactor, the reaction temperature is maintained at 20 to 150° C., and the reaction is carried out for 3 to 72 hours; finally, the lower layer of the mixture product in the reactor is washed with alkali, washed with water and dried, and enters the distillation system to obtain hydrofluoroether products with different structures.

[0066] Optionally, the fluorination reagent is composed of a fluoride salt, an additive and an anhydrous aprotic polar solvent, wherein the fluoride salt is preferably at least one of potassium fluoride, sodium fluoride, barium fluoride, silver fluoride and ammonium fluoride, and the additive includes tetrabutylammonium bromide. 464 reagent, at least one of dodecylmethylbenzyl ammonium bromide, octadecyltrimethylammonium iodide, 18-crown ether-6, 15-crown ether-5, and tetramethylethylenediamine; the anhydrous non-protonic polar solvent is a mixed solvent, which is a mixture of hexamethylphosphoric triamide and any one or more of adiponitrile, acetonitrile, N,N-dimethylformamide, dimethyl sulfoxide, 1,3-dimethyl-2-imidazolidinone, and cyclopentane sulfone. The hexamethylphosphoric triamide in the mixed solvent accounts for 1 to 99%, and more preferably 1 to 50%. The molar ratio of the main catalyst to the intermediate product in the fluorination catalyst system is 1 to 2:1.

[0067] Optionally, the alkylating agent includes trifluoroethyl trifluoromethanesulfonate, methyl trifluoromethanesulfonate, ethyl trifluoromethanesulfonate, dimethyl sulfate, diethyl sulfate, dimethyl carbonate, and diethyl carbonate.

[0068] Optionally, the hydrofluoroether product includes 1,1,1,2,2,3,3-heptafluoropropyl methyl ether, 1,1,1,2,2,3,3-heptafluoropropyl ethyl ether, 1,1,1,2,2,3,3-heptafluoropropyl trifluoroethyl ether, 2-trifluoromethyl-1,1,1,2,3,3-hexafluoropropyl methyl ether, 2-trifluoromethyl-1,1,1,2,3,3-hexafluoropropyl ethyl ether, 2-trifluoromethyl-1,1,1,2,3,3-hexafluoropropyl Methyl-1,1,1,2,3,3-hexafluoropropyl trifluoroethyl ether, 2,3-bis(trifluoromethyl)-1,1,1,2,3,-pentafluoropropyl methyl ether, 2,3-bis(trifluoromethyl)-1,1,1,2,3,-pentafluoropropyl ethyl ether, 2,3-bis(trifluoromethyl)-1,1,1,2,3,-pentafluoropropyl trifluoroethyl ether, 2-trifluoromethyl-3-methoxy-1,1,1, 2,3,4,4,5,5,5-pentafluoropentane, 2-trifluoromethyl-3-ethoxy-1,1,1,2,3,4,4,5,5,5-pentafluoropentane, 2-trifluoromethyl-3-(1,1,1-trifluoroethoxy)-1,1,1,2,3,4,4,5,5,5-pentafluoropentane, 2-trifluoromethoxy-1,1,1,2,3,3-hexafluoropropyl methyl ether, Oxy-1,1,1,2,3,3-hexafluoropropyl ethyl ether, 2-trifluoromethoxy-1,1,1,2,3,3-hexafluoropropyl trifluoroethyl ether, 2-pentafluoroethoxy-1,1,1,2,3,3-hexafluoropropyl methyl ether, 2-pentafluoroethoxy-1,1,1,2,3,3-hexafluoropropyl ethyl ether, 2-pentafluoroethoxy-1,1,1,2,3,3-hexafluoropropyl trifluoroethyl ether, etc.

[0069] The reaction process and principle of the present invention are described as follows:

[0070] A portion of the mixed gas collected from the deoxidation tower is introduced into the tower reactor in advance to fully combine with the fluoride ion catalyst, and the reaction temperature is maintained at -20 to 50°C. The catalyst solution is circulated for a period of time, and then the raw material is primed. The purpose is that the mixed gas acyl fluoride and fluoride ions form oxygen anions (RCF2O - ) and the acyl fluoride gas is in excess, when hexafluoropropylene or hexafluoropropylene oxide present in the mixed gas is introduced, it is directly attacked by oxygen anions to form intermediate products, reducing the self-polymerization of hexafluoropropylene to produce by-products such as hexafluoropropylene dimers and trimers.

[0071] Then the mixed gas and hexafluoropropylene are simultaneously introduced into the reactor at a molar ratio of 1 to 1.5:1 or the mixed gas is introduced separately, and the reaction temperature is controlled between -20 and 100°C, preferably 20 to 80°C. According to the prior art, carbonyl fluoride, perfluoroacetyl fluoride, perfluoropropionyl fluoride, hexafluoropropylene oxide and hexafluoropropylene can undergo nucleophilic addition reaction under the action of fluoride ion catalyst to produce carbonyl fluoride, ketone and other carbonyl compounds. The products synthesized by the reaction in this process are layered in a liquid separation tank, and the intermediate products in the lower layer are distilled to obtain intermediate products such as perfluoro-2-methyl-propionyl fluoride, perfluoro-2-methoxy-propionyl fluoride, perfluoro-4-methyl-2-butanone, and perfluoro-4-methyl-2-pentanone.

[0072] The process can be an intermittent reaction, a semi-continuous reaction or a continuous reaction, and the reactor can be a packed tower reactor, a tubular reactor or an intermittent stirred reactor, etc. The case of the present invention takes the reaction spray packed tower as an example to realize the continuous synthesis of fluorine-containing carbonyl compound intermediates. The fluoride ion catalyst solution is prepared by dissolving anhydrous metal fluoride salts, organic solvents, and additives at 80°C to 200°C, and passing fluorine-containing gas into the reaction, and then recycled in the reaction tower to reuse the catalyst. The product produced by the reaction is deposited in the separatory tank after one addition, realizing a one-step addition of the reaction and avoiding the generation of more by-products.

[0073] In addition, the product in the liquid separation tank and the fluorinating agent system are pumped into the alkylation reactor for alkylation reaction, the alkylating agent is in excess of 1.1 to 1.5 times, and the reaction temperature is controlled at 20 to 150°C, preferably 50 to 100°C. The reaction time is 3 to 72 hours, preferably 3 to 12 hours. After the reaction is completed, the lower layer product is washed with alkali and water to remove the excess alkylating agent, and then dried and entered into the distillation system to obtain different hydrofluoroether products.

[0074] The invention produces hexafluoropropylene oxide and simultaneously utilizes fluorine-containing waste gas as a resource and co-produces hydrofluoroether, so that the inevitable by-products in the process of producing hexafluoropropylene oxide by high-temperature oxidation of hexafluoropropylene no longer need to be washed and discharged to cause the cost of sewage treatment and the risk of sewage leakage, but the by-products are further reacted to synthesize corresponding high-value-added hydrofluoroether products. The method not only achieves the purpose of producing hexafluoropropylene oxide, but also makes full use of the high-value-added products produced by the reaction, so that the process is more reasonable, the flow is more optimized, and the industrialization is more economical.

[0075] The key to the present invention is to utilize the characteristics of the nucleophilic addition reaction of the by-product acyl fluoride in the raw material with hexafluoropropylene, and utilize the characteristics of the addition product for preparing hydrofluoroether by the same alkylation process, so as to obtain hydrofluoroether products with different structures. These hydrofluoroether products are widely used in the fields of semiconductor temperature control fluid, data center immersion heat exchange fluid, base station or weak current equipment charged cleaning agent and inert diluent, and have high added value.

[0076] The equation for the reaction process of the present invention is as follows:

[0077]

[0078] Where Me is -CH3, -CH2CH 3， -CH2CF3;

[0079] The process flow chart of the present invention is as follows Figure 1 As shown: the crude HFPO gas in the reactor is passed into the lightness removal tower, and the heavy components such as hexafluoropropylene oxide, hexafluoropropylene and some fluorinated solvents are separated under the conditions of controlling the pressure to 0-1.0 MPa and the tower top temperature to -40°C to 0°C, and the hexafluoropropylene oxide extraction and refining system is removed.

[0080] The light components separated from the top of the light removal tower enter the deoxygenation tower, and the non-condensable gases such as oxygen and carbon dioxide are removed under the conditions of controlling the pressure at 2.0Mpa and the top temperature at -30℃, and a fluorine-containing gas mixed with formyl fluoride, perfluoroacetyl fluoride, HFP, HFPO, and perfluoropropionyl fluoride is obtained. Of course, due to the different distillation control conditions and changes in the synthesis process conditions, the composition of the obtained mixed gas will change.

[0081] Fluorine-containing mixed gas and hexafluoropropylene are introduced into a spray tower reaction system, which includes a reaction tower, a liquid separator, a catalyst preparation tank, and a circulation pump. In the reaction tower, the reaction is carried out under the action of a fluorine ion catalyst. The density of the intermediate product produced by the reaction is greater than that of the organic solvent and is deposited in the lower layer of the liquid separator. The product leaves the reaction tower area, which can further avoid the secondary addition of the product and reduce the generation of by-products. At the same time, the upper catalyst is continuously circulated in the reaction system under the action of a circulation pump to participate in the reaction, thereby realizing continuous production.

[0082] The lower intermediate product layer is pumped into the alkylation reactor, a fluorination agent is added and stirred for a period of time, and then an alkylation agent is added to achieve the alkylation of the intermediate product. The alkylation product needs to pass through an alkali washing tower, a water washing tower and a drying tower, and is alkali washed, water washed and dried accordingly, and finally enters the distillation system to obtain different hydrofluoroether products, including product 1, product 2, and product 3.

[0083] The present invention is further described in detail below in conjunction with examples, but the present invention is not limited to the following examples.

[0084] Example 1

[0085] 15.91 kg of anhydrous cesium fluoride, 36.88 kg of 24-crown ether-8, and 500 L of anhydrous cyclopentane sulfone were added to a stirred reactor and dissolved at 80°C. Then, 8 kg of fluorine-containing gas (wherein the molar ratio of formyl:acetyl is 1:1) was introduced at room temperature for 1 to 2 hours. After the pressure was kept stable, a catalyst solution was obtained. The prepared fluoride ion catalyst solution is pumped into the liquid separation tank, and the catalyst circulation pump circulates the catalyst solution in the circulating bath spray tower reaction system. When the temperature of the reaction system is 0°C, the mixed gas collected in the deoxygenation tower (the produced HFPO crude product is treated by the light removal tower and the deoxygenation tower to obtain fluorine-containing waste gas, wherein the gas composition (mass ratio) is: formyl fluoride 30.2%, acetyl fluoride 63.8%, hexafluoropropylene 0.8%, perfluoropropionyl fluoride 0.3%, hexafluoropropylene oxide 4.9%) is slowly pumped into the reaction tower at 2 kg, and the catalyst is stably circulated for 0.5 to 1 hour. After the pressure is balanced, the temperature is raised to 45°C, and 6.4 kg / h of the mixed gas and 10 kg / h of hexafluoropropylene are respectively introduced into the reaction tower at the same time. The product obtained by the reaction is collected in the liquid separation tank, and the reaction is carried out for 10 hours, and 160 kg of the product is collected in the lower layer. The content of each component in the crude product was tested: perfluoropropionyl fluoride 0.12%, perfluoro-2-methyl-propionyl fluoride 37.22%, perfluoro-3-methyl-2-butanone 56.34%, perfluoro-2-methyl-3-pentanone 1.06%, perfluoro-2-methoxy-propionyl fluoride 1.63%, perfluoro-2-ethoxy-propionyl fluoride 1.89%, hexafluoropropylene dimer 1.74%.

[0086] Then, 41 kg of potassium fluoride, 18.66 kg of 18-crown ether-6, 173.56 kg of DMF, and 19.29 kg of hexamethylphosphoric triamide were added to the reactor to prepare a fluorinating agent solution, and 160 kg of the prepared intermediate was added. The mixture was stirred at 50 ° C for 1 hour, and then 98 kg of dimethyl sulfate was introduced. The reaction was continued for 8 hours. The lower layer product was washed with 10% KOH solution, washed with water and dried to obtain a product of about 178 kg. The crude product was analyzed to have a composition of 0.13% 1,1,1,2,2,3,3-heptafluoropropyl methyl ether, 0.13% 2-trifluoromethyl- 1,1,1,2,3,3-hexafluoropropyl methyl ether was 39.21%, 2,3-bis(trifluoromethyl)-1,1,1,2,3,-pentafluoropropyl methyl ether was 54.98%, 2-trifluoromethyl-3-methoxy-1,1,1,2,3,4,4,5,5,5-pentafluoropentane was 0.43%, 2-trifluoromethoxy-1,1,1,2,3,3-hexafluoropropyl methyl ether was 1.70%, 2-pentafluoroethoxy-1,1,1,2,3,3-hexafluoropropyl methyl ether was 1.93%, HFP dimer was 0.69%, and unknown matter was 0.93%.

[0087] Example 2

[0088] 10.89 kg of dry rubidium fluoride, 32.29 kg of 21-crown ether-7, 500 L of tetraethylene glycol dimethyl ether were added to the stirred reactor and stirred and dissolved at 90 ° C, and then 8 kg of fluorine-containing gas (wherein the molar ratio of formyl: acetyl is 1:1) was introduced at room temperature to react for 1 to 2 hours. The prepared fluorine ion catalyst solution was pumped into the liquid separator, and the catalyst solution was circulated in the circulating bath spray tower reaction system by the catalyst circulation pump. When the temperature of the reaction system was kept at 5 ° C, 2 kg of the mixed gas collected in the deoxidation tower in Example 1 was slowly pumped into the reaction tower, and the catalyst was stably circulated for 0.5 to 1 hour. After the pressure was balanced, the temperature was raised to 45 ° C, and 10 kg / h of the mixed gas and 10 kg / h of hexafluoropropylene were introduced into the reaction tower at the same time. The product obtained by the reaction was collected in the liquid separator, and the reaction was carried out for 10 hours. About 172 kg of the product was collected in the lower layer. The content of each component in the crude product was tested: perfluoropropionyl fluoride 0.12%, perfluoro-2-methyl-propionyl fluoride 41.03%, perfluoro-3-methyl-2-butanone 53.39%, perfluoro-2-methyl-3-pentanone 0.19%, perfluoro-2-methoxy-propionyl fluoride 2.43%, perfluoro-2-methyl-3-oxavalanyl fluoride 2.72%, and hexafluoropropylene dimer 0.12%.

[0089] Then, 41.2 kg of potassium fluoride, 18.74 kg of 18-crown ether-6, 190 kg of tetraethylene glycol dimethyl ether, and 10 kg of hexamethylphosphoric triamide were added to the reactor to prepare a fluorinating agent solution, and 172 kg of the intermediate prepared above was added. The mixture was stirred at 80° C. for 1 hour, and then 120 kg of diethyl sulfate was introduced. The reaction was continued for 6 hours. The lower layer product was washed with 10% KOH solution, washed with water, and dried to obtain a product of about 200 kg. The crude product was analyzed to have a composition of 0.18% 1,1,1,2,2,3,3-heptafluoropropyl ether. , 2-trifluoromethyl-1,1,1,2,3,3-hexafluoropropyl ethyl ether was 41.84%, 2,3-bis(trifluoromethyl)-1,1,1,2,3,-pentafluoropropyl ethyl ether was 52.58%, 2-trifluoromethyl-3-ethoxy-1,1,1,2,3,4,4,5,5,5-pentafluoropentane was 0.18%, 2-pentafluoroethoxy-1,1,1,2,3,3-hexafluoropropyl ethyl ether was 2.44%, 2-pentafluoroethoxy-1,1,1,2,3,3-hexafluoropropyl ethyl ether was 2.66%, and unknown matter was 0.12%.

[0090] Example 3

[0091] 6.0 kg of dried potassium fluoride, 27.45 kg of 18-crown ether-6, 500 L of acetonitrile were added to the stirred reactor and stirred and dissolved at 80 ° C, and then 8 kg of fluorine-containing gas (wherein the molar ratio of formyl: acetyl is 1:1) was introduced at room temperature to react for 1 to 2 hours. The prepared fluorine ion catalyst solution was pumped into the liquid separator, and the catalyst solution was circulated in the circulating bath spray tower reaction system by the catalyst circulation pump. When the temperature of the reaction system was kept at 10 ° C, 2 kg of the mixed gas collected in the deoxidation tower in Example 1 was slowly pumped into the reaction tower, and the catalyst was stably circulated for 0.5 to 1 hour. After the pressure was balanced, the temperature was raised to 50 ° C, and 6 kg / h of the mixed gas and 10 kg / h of hexafluoropropylene were introduced into the reaction tower at the same time. The product obtained by the reaction was collected in the liquid separator, and the reaction was carried out for 5 hours. About 166 kg of the product was collected in the lower layer. The content of each component in the crude product was tested: perfluoropropionyl fluoride 0.06%, perfluoro-2-methyl-propionyl fluoride 33.70%, perfluoro-3-methyl-2-butanone 62.13%, perfluoro-2-methyl-3-pentanone 0.53%, perfluoro-2-methoxy-propionyl fluoride 1.54%, perfluoro-2-methyl-3-oxavalanyl fluoride 1.87%, and hexafluoropropylene dimer 0.17%.

[0092] Then, 40 kg of potassium fluoride, 18.6 kg of 18-crown ether-6, and 0.5 kg of 464 reagent, 151.65 kg of acetonitrile, 37.91 kg of hexamethylphosphoric acid triamide, prepare a fluorinating agent solution, add 166 kg of the intermediate prepared above, stir at 50 ° C for 1 hour, then pass 124 kg of methyl trifluoromethanesulfonate, react for 8 hours, wash the lower layer product with 10% KOH solution, wash with water and dry to obtain about 182 kg of product. The crude product composition is 0.06% of 1,1,1,2,2,3,3-heptafluoropropyl methyl ether, 2-trifluoromethyl-1,1,1 , 2,3,3-hexafluoropropyl methyl ether was 34.30%, 2,3-bis(trifluoromethyl)-1,1,1,2,3,-pentafluoropropyl methyl ether was 61.62%, 2-trifluoromethyl-3-methoxy-1,1,1,2,3,4,4,5,5,5-pentafluoropentane was 0.58%, 2-trifluoromethoxy-1,1,1,2,3,3-hexafluoropropyl methyl ether was 1.52%, 2-pentafluoroethoxy-1,1,1,2,3,3-hexafluoropropyl methyl ether was 1.64%, and unknown matter was 0.28%.

[0093] Example 4

[0094] 4.4 kg of dried sodium fluoride, 23.06 kg of 15-crown ether-5, and 500 L of adiponitrile were added to the stirred reactor, stirred and dissolved at 120 ° C, and then 8 kg of fluorine-containing gas (wherein the molar ratio of formyl: acetyl is 1:1) was introduced at room temperature to react for 1 to 2 hours. The prepared fluorine ion catalyst solution was pumped into the liquid separator, and the catalyst solution was circulated in the circulating bath spray tower reaction system by the catalyst circulation pump. When the temperature of the reaction system was kept at 20 ° C, 5 kg of the mixed gas collected in the deoxidation tower in Example 1 was slowly pumped into the reaction tower, and the catalyst was stably circulated for 0.5 to 1 hour. After the pressure was balanced, the temperature was raised to 45 ° C, and 3.2 kg / h of the mixed gas and 5 kg / h of hexafluoropropylene were introduced into the reaction tower at the same time. The product obtained by the reaction was collected in the liquid separator, and the reaction was carried out for 10 hours. About 78 kg of the product was collected in the lower layer. The content of each component in the crude product was tested: perfluoropropionyl fluoride 0.03%, perfluoro-2-methyl-propionyl fluoride 37.80%, perfluoro-3-methyl-2-butanone 57.13%, perfluoro-2-methyl-3-pentanone 0.16%, perfluoro-2-methoxy-propionyl fluoride 1.62%, perfluoro-2-methyl-3-oxavalanyl fluoride 2.60%, and hexafluoropropylene dimer 0.66%.

[0095] Then, 13.4 kg of sodium fluoride, 7.02 kg of 15-crown ether-5, 50 kg of adiponitrile, and 100 kg of hexamethylphosphoric triamide were added to the reaction kettle to prepare a fluorinating agent solution, and 78 kg of the intermediate prepared above was added. The mixture was stirred at 50° C. for 1 hour, and then 68 kg of ethyl trifluoromethanesulfonate was introduced. The reaction was continued for 8 hours. The lower layer product was washed with 10% KOH solution, washed with water, and dried to obtain about 89 kg of the product. The crude product was analyzed to have a composition of 0.03% 1,1,1,2,2,3,3-heptafluoropropyl ether, 2- Trifluoromethyl-1,1,1,2,3,3-hexafluoropropyl ethyl ether was 38.87%, 2,3-bis(trifluoromethyl)-1,1,1,2,3,-pentafluoropropyl ethyl ether was 56.74%, 2-trifluoromethyl-3-ethoxy-1,1,1,2,3,4,4,5,5,5-pentafluoropentane was 0.16%, 2-trifluoromethoxy-1,1,1,2,3,3-hexafluoropropyl ethyl ether was 1.24%, 2-pentafluoroethoxy-1,1,1,2,3,3-hexafluoropropyl ethyl ether was 1.96%, and unknown matter was 1.00%.

[0096] Example 5

[0097] Add 18.33 kg of dry barium fluoride and 42.3 kg of 464 reagent, 500L of dimethyl sulfoxide are stirred and dissolved at 80°C, and then 8kg of fluorine-containing gas (wherein the molar ratio of formyl:acetyl is 1:1) is introduced at room temperature to react for 1 to 2 hours. The prepared fluorine ion catalyst solution is pumped into the liquid separator, and the catalyst circulating pump circulates the catalyst solution in the circulating bath spray tower reaction system. When the temperature of the reaction system is kept at 20°C, 5kg of the mixed gas collected in the deoxidation tower in Example 1 is slowly pumped into the reaction tower, and the catalyst is stably circulated for 0.5 to 1h. After the pressure is balanced, the temperature is raised to 45°C, and 3.2kg / h of the mixed gas and 5kg / h of hexafluoropropylene are introduced into the reaction tower at the same time. The product obtained by the reaction is collected in the liquid separator, and the reaction is carried out for 10h, and about 80kg of the product is collected in the lower layer. The content of each component in the crude product was tested: perfluoropropionyl fluoride 0.08%, perfluoro-2-methyl-propionyl fluoride 37.67%, perfluoro-3-methyl-2-butanone 56.03%, perfluoro-2-methyl-3-pentanone 0.43%, perfluoro-2-methoxy-propionyl fluoride 1.38%, perfluoro-2-methyl-3-oxavalanyl fluoride 1.75%, and hexafluoropropylene dimer 2.66%.

[0098] Then add 20.5kg of barium fluoride and 9.33kg of 464 reagent, 125 kg of dimethyl sulfoxide, 125 kg of hexamethylphosphoric acid triamide, prepare the second catalyst solution, add 81 kg of the intermediate prepared above, stir at 50 ° C for 1 hour, then pass 36.75 kg of trifluoroethyl trifluoromethanesulfonate, react for 8 hours, wash the lower layer product with 10% KOH solution, wash with water and dry to obtain about 105 kg of product. The crude product composition is 0.09% of 1,1,1,2,2,3,3-heptafluoropropyl trifluoroethyl ether and 2-trifluoromethyl-1,1,1,2,3,3-hexafluoropropyl trifluoroethyl ether. Fluoropropyl trifluoroethyl ether was 39.27%, 2,3-bis(trifluoromethyl)-1,1,1,2,3,-pentafluoropropyl trifluoroethyl ether was 54.88%, 2-trifluoromethyl-3-(1,1,1-trifluoroethoxy)-1,1,1,2,3,4,4,5,5,5-pentafluoropentane was 0.41%, perfluoro-2-methoxy-propyl trifluoroethyl ether was 1.35%, 2-trifluoromethoxy-1,1,1,2,3,3-hexafluoropropyl trifluoroethyl ether was 1.69%, HFP dimer was 1.03%, and unknown substances were 1.28%.

[0099] Example 6

[0100] 6.0 kg of dry potassium fluoride, 27.45 kg of 18-crown ether-6, and 500 L of acetonitrile were added to a stirred reactor and dissolved at 80°C. Then, 9.4 kg of fluorine-containing gas (wherein the molar ratio of formyl:acetyl is 1:1) was introduced at room temperature and reacted for 1 to 2 hours. The prepared fluorine ion catalyst solution is pumped into a separatory tank, and the catalyst solution is circulated in a circulating bath spray tower reaction system by a catalyst circulation pump, and the temperature is raised to 50° C. The mixed gas collected in the above-mentioned deoxidation tower (by controlling the process parameters of the rectification system, the collected mixed gas ratio is 13.9% of formyl fluoride, 27.0% of acetyl fluoride, 9.5% of hexafluoropropylene, 1.40% of perfluoropropionyl fluoride, and 48.2% of hexafluoropropylene oxide) is slowly pumped into the reaction tower, and the mixed gas is passed into the reaction tower at a rate of 10 kg / h. The product obtained by the reaction is collected in a separatory tank, and the reaction is carried out for 20 hours. About 182.5 kg of products are collected in the lower layer, of which 1.53% is perfluoropropionyl fluoride, 7.49% is perfluoro-2-methyl-propionyl fluoride, 9.23% is perfluoro-3-methyl-2-butanone, 36.90% is perfluoro-2-methoxy-propionyl fluoride, and 44.85% is perfluoro-2-methyl-3-oxavalanyl fluoride.

[0101] Then, 42 kg of potassium fluoride, 19.1 kg of 18-crown ether-6, and 0.5 kg of 464 reagent, 151.65 kg of acetonitrile, 37.91 kg of hexamethylphosphoric triamide, prepare fluorinating agent solution, add 182.5 kg of the intermediate prepared above, stir at 50 ° C for 1 hour, then pass 110 kg of dimethyl sulfate, react for 8 hours, wash the lower layer product with 10% KOH solution, wash with water and dry to obtain about 193 kg of product. The crude product composition is 1,1,1,2,2,3,3 -Heptafluoropropyl methyl ether was 1.58%, 2-trifluoromethyl-1,1,1,2,3,3-hexafluoropropyl methyl ether was 7.56%, 2,3-bis(trifluoromethyl)-1,1,1,2,3,-pentafluoropropyl methyl ether was 9.20%, 2-trifluoromethoxy-1,1,1,2,3,3-hexafluoropropyl methyl ether was 37.08%, and 2-pentafluoroethoxy-1,1,1,2,3,3-hexafluoropropyl methyl ether was 44.58%.

[0102] Example 7

[0103] The same as Example 6, except that the alkylating agent was changed to diethyl sulfate, the amount used was 135 kg, and 203.5 kg of product was obtained, of which 1,1,1,2,2,3,3-heptafluoropropyl ether was 1.62%, 2-trifluoromethyl-1,1,1,2,3,3-hexafluoropropyl ether was 7.62%, 2,3-bis(trifluoromethyl)-1,1,1,2,3,-pentafluoropropyl ether was 9.17%, 2-trifluoromethoxy-1,1,1,2,3,3-hexafluoropropyl ether was 37.23%, and 2-pentafluoroethoxy-1,1,1,2,3,3-hexafluoropropyl ether was 44.36%.

[0104] Example 8

[0105] The same as Example 6, except that the alkylating agent was changed to trifluoroethyl trifluoromethanesulfonate, the amount used was 185 kg, and 242.6 kg of product was obtained, with 1.73% of 1,1,1,2,2,3,3-heptafluoropropyl trifluoroethyl ether, 7.81% of 2-trifluoromethyl-1,1,1,2,3,3-hexafluoropropyl trifluoroethyl ether, 9.10% of 2,3-bis(trifluoromethyl)-1,1,1,2,3,-pentafluoropropyl trifluoroethyl ether, 37.69% of 2-trifluoromethoxy-1,1,1,2,3,3-hexafluoropropyl trifluoroethyl ether, and 43.67% of 2-pentafluoroethoxy-1,1,1,2,3,3-hexafluoropropyl trifluoroethyl ether.

[0106] The above are all embodiments of the present application, and the protection scope of the present application is not limited thereto. Moreover, the components of the fluorine-containing gas change under different distillation operating conditions, and the components of the obtained hydrofluoroether will also change accordingly. Therefore, any equivalent changes made according to the products, methods, and principles of the present application should be included in the protection scope of the present application.

[0107] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that the present invention includes but is not limited to the contents described in the above specific embodiments. Any modification that does not deviate from the functional and structural principles of the present invention will be included in the scope of the claims.

Claims

1. A method for producing hexafluoropropylene oxide from fluorine-containing waste gas and co-producing hydrofluoroether, characterized in that: The method comprises the following steps: firstly, reacting the fluorine-containing waste gas in the production of hexafluoropropylene oxide under the action of a fluorine ion catalyst system to generate a perfluorinated intermediate product; then, reacting the perfluorinated intermediate product with an alkylating agent under the action of a fluorinating agent to produce a hydrofluoroether product.

2. The method for producing hexafluoropropylene oxide from fluorine-containing waste gas and co-producing hydrofluoroether according to claim 1, characterized in that: The fluorine-containing waste gas reacts under the action of the fluorine ion catalyst system to generate a perfluorinated intermediate product, which comprises the following steps: adding a fluoride ion catalyst solution into the tower reaction system; Then, the fluorine-containing waste gas or hexafluoropropylene is introduced into the tower reaction system for continuous reaction, the reaction temperature is maintained at 20-100° C., the reaction is carried out for 3-12 hours, the reaction product is separated into layers in a liquid separation tank, and the intermediate product in the lower layer is distilled to obtain a perfluorinated intermediate product; Alternatively, before introducing the fluorine-containing waste gas into the tower reaction system or simultaneously introducing hexafluoropropylene for continuous reaction, part of the fluorine-containing waste gas is introduced into the reaction system, and the reaction temperature is maintained at -20 to 50°C. This part of the fluorine-containing waste gas is fully contacted with the circulating fluoride ion solution catalyst to react and form an activated intermediate.

3. The method for producing hexafluoropropylene oxide from fluorine-containing waste gas and co-producing hydrofluoroether according to claim 2, characterized in that: The preparation method of the fluoride ion catalyst solution is as follows: metal fluoride salt, organic solvent and auxiliary agent are stirred and dissolved at 50°C to 200°C, then the temperature is lowered to room temperature and fluorine-containing gas is introduced, and the reaction pressure is gradually reduced to equilibrium and the activation of the catalyst system is completed to obtain the fluoride ion catalyst solution.

4. A method for producing hexafluoropropylene oxide from fluorine-containing waste gas and co-producing hydrofluoroether according to claim 3, characterized in that: The metal fluoride salt is at least one of rubidium fluoride, cesium fluoride, potassium fluoride, sodium fluoride, silver fluoride, barium fluoride and ammonium fluoride; and / or, the auxiliary agent includes a quaternary ammonium salt, a metal carboxyl compound, and a cryptate; and / or, the organic solvent is at least one of adiponitrile, acetonitrile, tetrahydrofuran, diethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, N,N-dimethylformamide, dimethyl sulfoxide, 1,3-dimethyl-2-imidazolidinone and cyclopentane sulfone; and / or, the molar ratio of the metal fluoride salt to the auxiliary agent is 1:

1.

5. A method for producing hexafluoropropylene oxide from fluorine-containing waste gas and co-producing hydrofluoroether according to claim 4, characterized in that: The quaternary ammonium salts include tetrabutylammonium bromide, 464 reagent, dodecylmethylbenzylammonium bromide, octadecyltrimethylammonium iodide; and / or, the cryptate includes 15-crown-5, 18-crown-6, 18-diazacrown-6, 21-crown-7, 24-crown-8.

6. The method for producing hexafluoropropylene oxide from fluorine-containing waste gas and co-producing hydrofluoroether according to claim 2, characterized in that: When the fluorine-containing waste gas or hexafluoropropylene is introduced into the tower reaction system for continuous reaction, the molar ratio of the fluorine ion catalyst to the fluorine-containing waste gas is 0.01-0.5:1, and the molar ratio of the fluorine-containing waste gas to hexafluoropropylene is 1-1.5:

1.

7. The method for producing hexafluoropropylene oxide from fluorine-containing waste gas and co-producing hydrofluoroether according to claim 1, characterized in that: The perfluorinated intermediate product reacts with an alkylating agent under the action of a fluorinating agent to produce a hydrofluoroether, comprising the following steps: The intermediate product and the fluorination agent are introduced into the alkylation reactor and stirred to combine; An alkylation agent is added to the alkylation reactor, the reaction temperature is maintained at 20 to 150° C., and the reaction is carried out for 3 to 72 hours; the lower layer mixture product in the alkylation reactor is treated and enters a distillation system to obtain a hydrofluoroether product.

8. A method for producing hexafluoropropylene oxide with fluorine-containing waste gas and co-producing hydrofluoroether according to claim 7, characterized in that: The perfluorinated intermediate products include perfluoropropionyl fluoride, perfluoro-2-methyl-propionyl fluoride, perfluoro-3-methyl-2-butanone, perfluoro-2-methyl-3-pentanone, perfluoro-2-methoxy-propionyl fluoride, and perfluoro-2-ethoxy-propionyl fluoride; and / or, the fluorination reagent is prepared from a fluoride salt, an additive, and an anhydrous non-protonic polar solvent; and / or, the alkylation reagent includes trifluoroethyl trifluoromethanesulfonate, methyl trifluoromethanesulfonate, ethyl trifluoromethanesulfonate, dimethyl sulfate, diethyl sulfate, dimethyl carbonate, and diethyl carbonate.

9. A method for producing hexafluoropropylene oxide with fluorine-containing waste gas and co-producing hydrofluoroether according to claim 8, characterized in that: The fluoride salt is at least one of potassium fluoride, sodium fluoride, barium fluoride, silver fluoride and ammonium fluoride, and the molar ratio of the fluoride salt to the perfluorinated intermediate product is 1 to 2:1; and / or the additive includes tetrabutylammonium bromide, At least one of 464 reagent, dodecylmethylbenzylammonium bromide, octadecyltrimethylammonium iodide, 18-crown ether-6, 15-crown ether-5, and tetramethylethylenediamine; and / or the anhydrous aprotic polar solvent is a mixed solvent, which is a mixture of hexamethylphosphoric triamide and any one or more of adiponitrile, acetonitrile, N,N-dimethylformamide, dimethyl sulfoxide, 1,3-dimethyl-2-imidazolidinone and cyclopentane sulfone, and the mass percentage of hexamethylphosphoric triamide in the mixed solvent is 1 to 99%.

10. The method for producing hexafluoropropylene oxide from fluorine-containing waste gas and co-producing hydrofluoroether according to claim 1, characterized in that: The crude hexafluoropropylene oxide product is produced by passing the top component of the light-removing tower into the deoxidation tower to obtain the fluorine-containing waste gas; and / or the fluorine-containing waste gas includes hexafluoropropylene, hexafluoropropylene oxide, formyl fluoride, perfluoroacetyl fluoride and perfluoropropionyl fluoride, wherein the total content of formyl fluoride and perfluoroacetyl fluoride accounts for 30% to 99.5%.

11. A method for producing hexafluoropropylene oxide with fluorine-containing waste gas and co-producing hydrofluoroether according to claim 1, characterized in that: The molecular formula of the hydrofluoroether is as follows, wherein Me=CH3, CH2CH3, CH2CF3: The hydrofluoroethers include 1,1,1,2,2,3,3-heptafluoropropyl methyl ether, 1,1,1,2,2,3,3-heptafluoropropyl ethyl ether, 1,1,1,2,2,3,3-heptafluoropropyl trifluoroethyl ether, 2-trifluoromethyl-1,1,1,2,3,3-hexafluoropropyl methyl ether, 2-trifluoromethyl-1,1,1,2,3,3-hexafluoropropyl ethyl ether, 2-trifluoromethyl-1,1,1,2,3,3-hexafluoropropyl 1,1,2,3,3-hexafluoropropyl trifluoroethyl ether, 2,3-bis(trifluoromethyl)-1,1,1,2,3,-pentafluoropropyl methyl ether, 2,3-bis(trifluoromethyl)-1,1,1,2,3,-pentafluoropropyl ethyl ether, 2,3-bis(trifluoromethyl)-1,1,1,2,3,-pentafluoropropyl trifluoroethyl ether, 2-trifluoromethyl-3-methoxy-1,1,1,2,3 ,4,4,5,5,5-pentafluoropentane, 2-trifluoromethyl-3-ethoxy-1,1,1,2,3,4,4,5,5,5-pentafluoropentane, 2-trifluoromethyl-3-(1,1,1-trifluoroethoxy)-1,1,1,2,3,4,4,5,5,5-pentafluoropentane, 2-trifluoromethoxy-1,1,1,2,3,3-hexafluoropropyl methyl ether, 1,1,1,2,3,3-hexafluoropropyl ethyl ether, 2-trifluoromethoxy-1,1,1,2,3,3-hexafluoropropyl trifluoroethyl ether, 2-pentafluoroethoxy-1,1,1,2,3,3-hexafluoropropyl methyl ether, 2-pentafluoroethoxy-1,1,1,2,3,3-hexafluoropropyl ethyl ether, 2-pentafluoroethoxy-1,1,1,2,3,3-hexafluoropropyl trifluoroethyl ether.

12. A method for producing hexafluoropropylene oxide with fluorine-containing waste gas to co-produce hydrofluoroether according to claim 2, characterized in that: The tower reaction system includes a catalyst circulation pump, a main reactor connected to the circulation pump, a liquid phase separation tank connected to the main reactor, and a catalyst synthesis kettle connected to the liquid phase separation tank. During the entire reaction process, the catalyst is continuously circulated under the action of the circulation pump; the main reactor is a countercurrent reactor or a liquid flow contact reactor, including a spray tower reactor, a packed tower reactor, a plate tower reactor, a bubbling reactor, and a tubular reactor.

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