An apparatus for the ozonolysis of perfluoroolefins to produce fluorine-containing intermediates
Patent Information
- Application Number
- CN202522192734.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-16
- Publication Date
- 2026-10-09
- Estimated Expiration
- 2035-10-16
AI Technical Summary
但是,臭氧裂解反应过程中会形成不稳定的过氧化物尤其是初级臭氧化物(Primary Ozonide),控制不好有发生爆炸的风险,生产过程中存在安全隐患
[0316]1)本申请通过优化反应器组合,提高了气液反应效率,臭氧利用率大幅度提升,同时提高了反应的选择性,有效抑制了副反应,从而减少了副产物的生成;
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Figure CN224822626U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of perfluorinated chemical technology, and in particular to an apparatus for preparing fluorine-containing intermediates by ozone cracking of perfluoroolefins. Background Technology
[0002] Perfluoroacyl fluorides, such as carboacyl fluoride, trifluoroacetyl fluoride, pentafluoropropionyl fluoride, heptafluoroisobutyryl fluoride, heptafluoron-butyryl fluoride, and trifluoromethyl fluoroformate, are an important class of fluorine-containing intermediates with high added value, widely used in the manufacture of pharmaceuticals, pesticides, fluorine-containing monomers, and electronic chemicals for semiconductors.
[0003] For a long time, electrolytic fluorination has dominated the production of perfluoroacyl fluoride. However, the electrolytic method has problems such as low efficiency, high cost of electrolytic plates, high equipment costs, and high pollution.
[0004] In recent years, the synthesis of perfluoroacyl fluorides through chemical methods, including thermal pyrolysis and photochemical pyrolysis, has gradually gained attention. However, current processes suffer from drawbacks such as high pyrolysis temperatures, poor reaction selectivity, demanding reaction conditions, the need for catalysts, and high requirements for reaction equipment. Therefore, they are challenging to implement in practice and are not the most ideal methods.
[0005] Ozone decomposition, as a mild and efficient method, has attracted attention in recent years. However, the ozone decomposition reaction forms unstable peroxides, especially primary ozonides, which pose an explosion risk if not properly controlled, creating safety hazards during production. Furthermore, the intermediates formed during ozone decomposition, especially criegee intermediates (carbonyl oxides), are highly reactive and prone to initiating side reactions, leading to byproduct formation. This reduces reaction selectivity and increases the difficulty of product separation and purification. Moreover, ozone preparation is energy-intensive, with higher costs compared to common oxidants such as oxygen and hydrogen peroxide, making it unsuitable for the production of low-value-added products. To date, the successful industrial application of ozone decomposition technology remains very limited. Utility Model Content
[0006] In view of this, the technical problem to be solved by this utility model is to provide an apparatus for preparing fluorine-containing intermediates by ozone cracking of perfluoroolefins, which improves the raw material conversion rate and can realize industrial-grade ozone cracking reaction.
[0007] This application provides an apparatus for preparing fluorine-containing intermediates by ozone cracking of perfluoroolefins, comprising:
[0008] Cracking equipment for ozonochemical cracking of perfluoroolefins with an oxygen-ozone mixture;
[0009] Product selective absorption and / or cryogenic condensation recovery equipment, separation equipment, and purification equipment;
[0010] Equipment for exhaust gas absorption, separation and purification.
[0011] The pyrolysis equipment preferably includes:
[0012] The equipment includes a raw material mixing tank, an ozone generator, and a pyrolysis reaction device; the pyrolysis reaction device includes one or more of the following connected in series: a falling film reactor, a pyrolysis vessel, and a pyrolysis tower.
[0013] The raw material mixing tank is used for raw material mixing. In the raw material mixing tank, the solvent and reactants are mixed in a certain proportion to obtain a perfluoroolefin solution with a concentration of 1 wt% to 100 wt%. The latter flows into the pyrolysis equipment at a constant rate through a metering valve to carry out the ozonolysis reaction.
[0014] The ozone generator is used to generate an ozone-oxygen mixture. Preferably, the ozone concentration in the outlet gas of the ozone generator is 2 wt% to 20 wt%; the outlet gas pressure is 1 to 3 MPa. As needed, a pressurizing device can be used to pressurize the ozone-oxygen mixture. Preferably, the pressurizing device is a liquid ring pump.
[0015] The pyrolysis reactor can be one, two, or a combination of three types of reactors: falling film reactor, pyrolysis vessel, and pyrolysis tower.
[0016] In some specific embodiments of the present invention, the pyrolysis reactor is a falling film reactor, such as... Figure 1 As shown.
[0017] The lower end of the falling film reactor is provided with an air inlet for the oxygen-ozone mixture and the reaction raw material gas to enter the falling film reactor.
[0018] The falling film reactor is also equipped with a liquid outlet at its lower end for discharging the reaction liquid.
[0019] The falling film reactor is equipped with a liquid inlet at the top for the entry of liquid reaction raw materials.
[0020] The falling film reactor is equipped with a gas outlet at the top for the gaseous products to escape during the reaction.
[0021] Preferably, the top of the falling film reactor is equipped with a liquid phase distributor, which is connected to the outlet of the raw material batching tank via a metering valve. This allows the liquid phase reaction raw materials to be evenly distributed and form a downward-flowing liquid film on the inner wall of the falling film reactor, thereby improving ozone utilization and raw material conversion rate and obtaining a higher reaction yield.
[0022] Preferably, the outer wall of the falling film reactor is provided with a cooling jacket, and the cooling medium enters from the lower inlet and flows out from the upper outlet, which can stably control the reaction temperature.
[0023] This invention does not limit the technical parameters of the falling film reactor, and those skilled in the art can design and optimize it according to production needs.
[0024] Preferably, the pyrolysis reaction in the falling film reactor is as follows:
[0025] The liquid inlet of the falling film reactor is connected to the raw material mixing tank via a metering valve, and the liquid outlet is connected to a reaction liquid recovery tank. The gas inlet is connected to ozone and gaseous raw materials via a flow meter, and the outlet is connected to the reaction tail gas condensation and recovery system. Before the reaction, the reaction system is heated and evacuated to remove water, then nitrogen is introduced and the pressure is maintained before cooling to room temperature.
[0026] Add the liquid reaction raw materials to the raw material mixing tank.
[0027] The falling film reactor is heated to a higher temperature.
[0028] Liquid reaction raw materials flow uniformly from the raw material mixing tank through a metering valve into the liquid phase distributor at the top of the falling film reactor. After being evenly distributed, the liquid film forms on the inner wall of the falling film reactor and flows downward.
[0029] The ozone-oxygen mixture and the feed gas are introduced into the falling film reactor through the gas phase inlet at the bottom, flowing upwards to react with the liquid film. The gas flow rate is controlled by a mass flow meter.
[0030] The residual reaction liquid is discharged from the liquid outlet at the bottom of the falling film reactor and enters the reaction liquid recovery tank. The reaction liquid in the recovery tank is either directly sent to the raw material batching tank for recycling or treated before being sent to the raw material batching tank for recycling.
[0031] The preferred gas-liquid contact time in the falling film reactor is 1 to 10 minutes; the preferred temperature is 30 to 50°C; and the preferred inlet pressure is 0.15 to 0.25 MPa.
[0032] In this invention, when the perfluoroolefin is liquid, the reactants and solvent are mixed and added to a falling film reactor, where they react with an ozone-oxygen mixture. The gaseous products of the reaction are discharged with excess oxygen and proceed to the next step.
[0033] In some specific embodiments of the present invention, the liquid reaction raw material is perfluoro-4-methyl-2-pentene, and the solvent is trifluoroacetic acid. Perfluoro-4-methyl-2-pentene and trifluoroacetic acid are added to the raw material mixing tank, mixed evenly, and then flowed at a constant rate into the falling film reactor through a metering valve. After being evenly distributed by a liquid phase distributor located at the top, a downward-flowing liquid film is formed on the inner wall of the falling film reactor. An ozone-oxygen mixture is then introduced from the air inlet at the bottom of the falling film reactor, flowing upwards to react with the liquid film.
[0034] The liquid flow rate is preferably 1~500 g / h, more preferably 1~100 g / h.
[0035] The preferred inlet velocity of the ozone-oxygen mixture is 50-500 SCCM, more preferably 50-250 SCCM.
[0036] In this invention, when the perfluoroolefin is in the form of a gas, the solvent is added to the falling film reactor. The gaseous reactants are introduced into the falling film reactor in gaseous form to mix with the solvent and react with the ozone-oxygen mixture. The gaseous products of the reaction are discharged with excess oxygen and proceed to the next process.
[0037] In some specific embodiments of the present invention, the gaseous reaction raw material is hexafluoropropylene, and the solvent is trifluoroacetic acid. Trifluoroacetic acid is added to the raw material mixing tank and flows into the falling film reactor at a uniform rate through a metering valve. After being evenly distributed by a liquid phase distributor set at the top, a downward flowing liquid film is formed on the inner wall of the falling film reactor. Ozone-oxygen mixed gas and hexafluoropropylene are added from the air inlet at the bottom of the falling film reactor, flowing upward and reacting with the liquid film.
[0038] The liquid flow rate is preferably 1~250 g / h, more preferably 1~100 g / h.
[0039] The inlet velocity of the gaseous reaction raw material is preferably 1~200 SCCM, more preferably 1~100 SCCM; the inlet velocity of the ozone-oxygen mixed gas is preferably 10~500 SCCM, more preferably 50-200 SCCM.
[0040] In some specific embodiments of the present invention, the pyrolysis reactor is a pyrolysis vessel. For example... Figure 2 As shown.
[0041] The top of the pyrolysis vessel is equipped with a gas inlet and a liquid inlet, which are used for the entry of gaseous and liquid reaction raw materials, respectively.
[0042] The top of the pyrolysis vessel is also provided with a gas outlet for the gaseous products to escape during the reaction.
[0043] The bottom of the pyrolysis vessel is provided with a liquid outlet for discharging the reaction liquid.
[0044] Preferably, the pyrolysis vessel is equipped with a cooling jacket, with the cooling medium entering from the lower inlet and exiting from the upper outlet, which can more stably control the reaction temperature.
[0045] Preferably, the pyrolysis vessel is equipped with a stirrer to maintain a uniform liquid phase composition within the vessel. More preferably, the stirrer is a self-priming impeller to improve the gas intake rate, gas content in the reaction liquid, gas-liquid volumetric mass transfer coefficient, and gas-liquid mass transfer area within the pyrolysis vessel.
[0046] The present invention does not limit the technical parameters of the pyrolysis vessel, and those skilled in the art can design and optimize it according to production needs.
[0047] Preferably, the pyrolysis reaction in the pyrolysis reactor is as follows:
[0048] The pyrolysis reactor is connected to the raw material mixing tank, the bottom liquid outlet, and a reaction liquid recovery tank. The gas inlet is connected to ozone and gaseous raw materials, and the outlet is connected to the reaction tail gas condensation and recovery system. Before the reaction, the reaction system is heated and evacuated to remove water, then nitrogen is introduced and the pressure is maintained before cooling to room temperature.
[0049] The reaction raw materials are added to the raw material mixing tank. Before the reaction starts, liquid raw materials are added to the cracking reactor through the metering valve until the liquid level in the reactor reaches the target value.
[0050] The pyrolysis reactor is started with stirring and heating.
[0051] The ozone-oxygen mixture and the feed gas are introduced into the reactor through the gas phase inlet of the pyrolysis vessel, where they react with the liquid feed inside the vessel. The gas flow rate is controlled by a mass flow meter.
[0052] During the reaction, liquid reactants flow uniformly from the feed tank into the pyrolysis reactor via a metering valve. The reaction liquid is discharged from the bottom liquid outlet as needed, maintaining stable composition and liquid level within the reactor. The reaction liquid in the recovery tank is either directly sent to the feed tank for recycling or treated before being sent back for recycling.
[0053] The preferred gas-liquid contact time in the pyrolysis reactor is 1 to 25 minutes; the preferred temperature is 30 to 50°C; and the preferred inlet pressure is 0.15 to 0.25 MPa.
[0054] In this invention, when the perfluoroolefin is liquid, the reactants and solvent are mixed and added to a pyrolysis reactor, where they react with an ozone-oxygen mixture. The gaseous products of the reaction are discharged from the reactor with excess oxygen and proceed to the next step.
[0055] In some specific embodiments of the present invention, the liquid reaction raw material is perfluoro-4-methyl-2-pentene, and the solvent is trifluoroacetic acid. Perfluoro-4-methyl-2-pentene and trifluoroacetic acid are added to the raw material mixing tank. During the reaction, perfluoro-4-methyl-2-pentene and trifluoroacetic acid flow into the pyrolysis reactor at a uniform rate through a metering valve, and an ozone-oxygen mixture is added from the inlet of the pyrolysis reactor to react with the liquid raw material inside the reactor.
[0056] The liquid flow rate is preferably 1~500 g / h, more preferably 10~100 g / h.
[0057] The preferred inlet velocity of the ozone-oxygen mixture is 50-500 SCCM, more preferably 50-250 SCCM.
[0058] In this invention, when the perfluoroolefin is a gas, the solvent is added to the pyrolysis reactor, and the gaseous reactants are introduced into the pyrolysis reactor in gaseous form to mix with the solvent and react with the ozone-oxygen mixture. The gaseous products of the reaction are discharged from the reactor with excess oxygen and enter the next process.
[0059] In some specific embodiments of the present invention, the gaseous reaction feedstock is hexafluoropropylene gas, and the solvent is trifluoroacetic acid. Trifluoroacetic acid is added to the feedstock mixing tank. During the reaction, the trifluoroacetic acid flows into the pyrolysis reactor at a uniform rate through a metering valve. Ozone-oxygen mixed gas and gaseous reaction feedstock are added from the gas inlet at the bottom of the pyrolysis reactor, contacting the reaction liquid inside the reactor to carry out an oxidative pyrolysis reaction.
[0060] The liquid flow rate is preferably 1~250 g / h, more preferably 1~100 g / h.
[0061] The inlet velocity of the gaseous reaction raw material is preferably 1~200 SCCM, more preferably 1~100 SCCM; the inlet velocity of the ozone-oxygen mixed gas is preferably 10~500 SCCM, more preferably 50-200 SCCM.
[0062] In some specific embodiments of the present invention, the pyrolysis reactor is a pyrolysis tower. For example... Figure 3 As shown.
[0063] The top of the pyrolysis tower is equipped with a liquid inlet for the liquid reaction raw materials to enter.
[0064] Preferably, the top of the pyrolysis tower is equipped with a liquid phase distributor, which can make the reaction raw materials evenly distributed and form a downward flowing liquid film on the surface of the packing in the pyrolysis tower, thereby improving ozone utilization and raw material conversion rate and obtaining a higher reaction yield.
[0065] The top of the pyrolysis tower is also equipped with a gas outlet for the escape of gaseous products during the reaction process.
[0066] The lower end of the pyrolysis tower is provided with an air inlet for the oxygen-ozone mixed gas and the reaction raw material gas to enter the pyrolysis tower.
[0067] The lower end of the pyrolysis tower is also provided with a liquid outlet for discharging the reaction liquid.
[0068] Preferably, the pyrolysis tower is provided with multiple layers of packing material to provide sufficient mass transfer area.
[0069] Preferably, the outer wall of the pyrolysis tower is provided with a cooling jacket, and the cooling medium enters from the lower inlet and flows out from the upper outlet, which can stably control the reaction temperature.
[0070] The present invention does not limit the technical parameters of the pyrolysis tower, and those skilled in the art can design and optimize it according to production needs.
[0071] Preferably, the pyrolysis reaction in the pyrolysis tower is as follows:
[0072] The pyrolysis tower is connected to a raw material mixing tank via a metering valve, and its bottom liquid outlet is connected to a reaction liquid recovery tank. The gas inlet is connected to ozone and the gaseous raw material, and the outlet is connected to a reaction tail gas condensation and recovery system. Before the reaction, the reaction system is heated and evacuated to remove water, then nitrogen is introduced and the pressure is maintained before cooling to room temperature.
[0073] The reactants are added to the feed tank and flow at a constant speed from the feed tank into the liquid distributor at the top of the cracking tower through the metering valve. After being evenly distributed, the liquid film forms on the surface of the packing material in the cracking tower and flows downward.
[0074] The pyrolysis tower is heated to a higher temperature.
[0075] The ozone-oxygen mixture and the feed gas are introduced into the reactor from the gas phase inlet at the bottom of the pyrolysis tower, flowing upwards and reacting with the liquid film. The gas flow rate is controlled by a mass flow meter.
[0076] Unreacted liquid feedstock is discharged from the liquid outlet at the bottom of the column and enters the reaction liquid recovery tank. The reaction liquid in the recovery tank is either directly sent to the feedstock batching tank for recycling or treated before being sent to the feedstock batching tank for recycling.
[0077] The preferred gas-liquid contact time in the pyrolysis tower is 1 to 15 minutes; the preferred temperature is 30 to 50°C; and the preferred inlet pressure is 0.15 to 0.25 MPaPa.
[0078] In this invention, when the perfluoroolefin is liquid, the reactants and solvent are mixed and added to the cracking tower, where they react with an ozone-oxygen mixture. The gaseous products of the reaction are discharged from the reactor with excess oxygen and proceed to the next process.
[0079] In some specific embodiments of the present invention, the liquid reaction raw material is perfluoro-4-methyl-2-pentene, and the solvent is trifluoroacetic acid. Perfluoro-4-methyl-2-pentene and trifluoroacetic acid are added to the raw material mixing tank, mixed evenly, and then flowed into the cracking tower at a constant rate through a metering valve. An ozone-oxygen mixture is added from the gas inlet at the bottom of the cracking tower, flows upward, and reacts with the liquid.
[0080] The liquid flow rate is preferably 1~500 g / h, more preferably 10~100 g / h.
[0081] The preferred inlet velocity of the ozone-oxygen mixture is 50-500 SCCM, more preferably 50-250 SCCM.
[0082] In this invention, when the perfluoroolefin is a gas, the solvent is added to the cracking reactor, and the gaseous reactants are introduced into the cracking tower in gaseous form to mix with the solvent and react with the ozone-oxygen mixture. The gaseous products of the reaction are discharged from the reactor with excess oxygen and enter the next process.
[0083] In some specific embodiments of the present invention, the gaseous reaction feedstock is hexafluoropropylene gas, and the solvent is trifluoroacetic acid. Trifluoroacetic acid is added to the feedstock mixing tank and flows into the cracking tower at a uniform rate through a metering valve. Ozone-oxygen mixed gas and gaseous reaction feedstock are added from the gas inlet at the bottom of the cracking tower, flowing upward and reacting with the liquid.
[0084] The liquid flow rate is preferably 1~250 g / h, more preferably 1~100 g / h.
[0085] The inlet velocity of the gaseous reaction raw material is preferably 1~200 SCCM, more preferably 1~100 SCCM; the inlet velocity of the ozone-oxygen mixed gas is preferably 10~500 SCCM, more preferably 50~200 SCCM.
[0086] In some specific embodiments of the present invention, the pyrolysis reactor is a falling film reactor and a pyrolysis vessel connected in sequence. For example... Figure 4 As shown.
[0087] The falling film reactor and the pyrolysis vessel are connected in series, and the falling film reactor is connected to the raw material batching tank.
[0088] The liquid outlet at the bottom of the falling film reactor is connected to the liquid inlet at the top of the pyrolysis vessel.
[0089] The gas outlet at the top of the falling film reactor is connected to the gas inlet at the top of the pyrolysis vessel.
[0090] The top of the pyrolysis vessel is provided with a gas outlet for the gaseous products to escape during the reaction.
[0091] The bottom of the pyrolysis vessel is provided with a liquid outlet for discharging the reaction liquid.
[0092] The setup and parameters of the falling film reactor and pyrolysis vessel are the same as described above, and will not be repeated here.
[0093] Preferably, the pyrolysis reaction in the pyrolysis apparatus is as follows:
[0094] The falling film reactor is connected to the raw material mixing tank, and its bottom liquid outlet is connected to the liquid phase inlet of the pyrolysis reactor. The gas inlet of the falling film reactor is connected to ozone and gaseous raw materials, and its outlet is connected to the gas phase inlet of the pyrolysis reactor. The gas phase outlet of the pyrolysis reactor is connected to the reaction tail gas condensation and recovery system, and the bottom liquid outlet of the pyrolysis reactor is connected to a reaction liquid recovery tank. Before the reaction, the reaction system is heated and evacuated to remove water, then nitrogen is introduced and the pressure is maintained before cooling to room temperature.
[0095] Liquid reactants are added to the feed tank. The liquid reactants flow uniformly from the feed tank through a metering valve into the liquid distributor at the top of the falling film reactor. After being evenly distributed, a liquid film forms on the inner wall of the falling film reactor and flows downwards. Finally, the liquid reactants flow out from the liquid outlet at the bottom of the falling film reactor and flow into the pyrolysis reactor through a metering valve at the liquid inlet until the liquid level in the pyrolysis reactor reaches the target value.
[0096] The falling film reactor is heated to a higher temperature.
[0097] The pyrolysis reactor is started with stirring and heating.
[0098] The ozone-oxygen mixture and the raw material gas are introduced into the falling film reactor from the gas phase inlet at the bottom of the reactor. They flow upward and react with the liquid film. The gas flow rate is controlled by a mass flow meter.
[0099] The reaction tail gas exiting the gas phase outlet of the falling film reactor flows into the pyrolysis vessel from the gas phase inlet, where it reacts with the liquid material in the pyrolysis vessel.
[0100] Finally, the gaseous products from the reaction vessel are discharged from the gas phase outlet along with excess oxygen and proceed to the next process.
[0101] The reaction liquid is discharged through the liquid phase outlet at the bottom of the pyrolysis reactor as needed to maintain stable composition and liquid level within the reactor. The reaction liquid in the recovery tank is either directly sent to the raw material batching tank for recycling or treated before being sent to the raw material batching tank for recycling.
[0102] The preferred gas-liquid contact time in the falling film reactor is 1 to 10 minutes; the preferred temperature is 30 to 50°C; and the preferred inlet pressure is 0.15 to 0.25 MPa.
[0103] The preferred gas-liquid contact time in the pyrolysis reactor is 1 to 25 minutes; the preferred temperature is 30 to 50°C; and the preferred inlet pressure is 0.15 to 0.25 MPa.
[0104] In this invention, when the perfluoroolefin is liquid, the reactants and solvent are mixed and added to the pyrolysis reactor, where they react with an ozone-oxygen mixture. The gaseous products of the reaction are discharged from the reactor with excess oxygen and proceed to the next step.
[0105] In some specific embodiments of the present invention, the liquid reaction feedstock is perfluoro-4-methyl-2-pentene, and the solvent is trifluoroacetic acid. Perfluoro-4-methyl-2-pentene and trifluoroacetic acid are added to the feedstock mixing tank, mixed evenly, and then flowed at a constant speed from the feedstock mixing tank into the liquid phase distributor at the top of the falling film reactor through a metering valve. After uniform distribution, a liquid film forms on the inner wall of the falling film reactor and flows downwards. Then, the liquid reaction feedstock flows out from the liquid outlet at the bottom of the falling film reactor and flows into the pyrolysis reactor through the liquid inlet of the pyrolysis reactor through a metering valve until the liquid level in the pyrolysis reactor reaches the target value.
[0106] The falling film reactor is heated to a higher temperature.
[0107] The pyrolysis reactor is started with stirring and heating.
[0108] An ozone-oxygen mixture is generated using an ozone generator. This mixture enters the falling film reactor through a gas-phase inlet at the bottom, flows upwards, and reacts with the liquid film.
[0109] The reaction tail gas exiting the gas phase outlet of the falling film reactor flows into the pyrolysis vessel from the gas phase inlet, where it reacts with the liquid material in the pyrolysis vessel.
[0110] Finally, the gaseous products from the reaction are discharged from the pyrolysis reactor along with excess oxygen and proceed to the next process. The reaction liquid is discharged through the liquid outlet at the bottom of the reactor as needed to maintain stable composition and liquid level within the reactor.
[0111] The liquid flow rate is preferably 1~500 g / h, more preferably 10~100 g / h.
[0112] The preferred inlet velocity of the ozone-oxygen mixture is 50-500 SCCM, more preferably 50-250 SCCM.
[0113] In this invention, when the perfluoroolefin is a gas, the solvent is added to the pyrolysis reactor. The gaseous reactants are introduced into the pyrolysis reactor in gaseous form to mix with the solvent and react with the ozone-oxygen mixture. The gaseous products of the reaction are discharged from the reactor with excess oxygen and enter the next process.
[0114] In some specific embodiments of the present invention, the gaseous reactant is hexafluoropropylene gas, and the solvent is trifluoroacetic acid. Trifluoroacetic acid is added to the raw material mixing tank. It flows uniformly from the raw material mixing tank into the liquid phase distributor at the top of the falling film reactor via a metering valve, and after being evenly distributed, forms a liquid film on the inner wall of the falling film reactor and flows downwards. Then, the liquid reactant flows out from the liquid outlet at the bottom of the falling film reactor and flows into the pyrolysis reactor through the liquid inlet via a metering valve until the liquid level in the pyrolysis reactor reaches the target value.
[0115] The falling film reactor is heated to a higher temperature.
[0116] The pyrolysis reactor is started with stirring and heating.
[0117] An ozone-oxygen mixture is generated using an ozone generator. The ozone-oxygen mixture and hexafluoropropylene gas enter the reactor from the gas phase inlet at the bottom of the falling film reactor, flow upward, and come into contact with and react with the liquid film.
[0118] The reaction tail gas exiting the gas phase outlet of the falling film reactor flows into the pyrolysis vessel from the gas phase inlet, where it reacts with the liquid material in the pyrolysis vessel.
[0119] Finally, the gaseous products from the reaction are discharged from the pyrolysis reactor along with excess oxygen and proceed to the next process. The reaction liquid is discharged through the liquid outlet at the bottom of the reactor as needed to maintain stable composition and liquid level within the reactor.
[0120] The liquid flow rate is preferably 1~250 g / h, more preferably 1~100 g / h.
[0121] The inlet velocity of the gaseous reaction raw material is preferably 1~200 SCCM, more preferably 1~100 SCCM; the inlet velocity of the ozone-oxygen mixed gas is preferably 10~500 SCCM, more preferably 50~200 SCCM.
[0122] While falling film reactors offer advantages in temperature control, they suffer from relatively small gas-liquid volumetric mass transfer coefficients and gas-liquid mass transfer interfaces. Furthermore, the lack of mixing within the liquid phase results in poor compositional uniformity. Using a falling film reactor alone leads to low feed conversion rates, difficulty in reaction control, and a tendency to generate byproducts. While pyrolysis reactors can achieve an ideal balance between temperature control and mass transfer interfaces, and offer the best liquid phase composition uniformity, especially with high gas uptake rate, gas content, gas-liquid volumetric mass transfer coefficient, and gas-liquid interface achieved through self-aspirating stirring, the process requires intensive dispersion and stirring, resulting in high stirring power, much of which is converted into heat energy, placing high demands on system heat transfer and complicating equipment structure. Using a pyrolysis reactor alone also results in high energy consumption. This invention employs a falling film reactor and a pyrolysis reactor connected in series as a pyrolysis reactor, overcoming the drawbacks of using either a falling film reactor or a pyrolysis reactor alone, achieving higher feed conversion rates, better reaction control (lower byproducts), and lower energy consumption.
[0123] In some specific embodiments of the present invention, the pyrolysis reactor is a pyrolysis vessel and a pyrolysis tower connected in sequence. For example... Figure 5 As shown.
[0124] The pyrolysis reactor and the pyrolysis tower are connected in series, and the pyrolysis reactor is connected to the raw material batching tank.
[0125] The liquid outlet at the bottom of the pyrolysis vessel is connected to the liquid inlet at the top of the pyrolysis tower.
[0126] The gas outlet at the top of the pyrolysis reactor is connected to the gas inlet at the bottom of the pyrolysis tower.
[0127] The pyrolysis tower is equipped with a liquid outlet at the bottom.
[0128] The setup and parameters of the pyrolysis vessel and pyrolysis tower are the same as described above, and will not be repeated here.
[0129] Preferably, the pyrolysis reactions in the pyrolysis vessel and pyrolysis tower reactor are as follows:
[0130] The pyrolysis reactor is connected to the raw material mixing tank, and its bottom liquid outlet is connected to the liquid phase inlet of the pyrolysis tower. The gas inlet of the pyrolysis reactor is connected to ozone and gaseous raw materials, and its outlet is connected to the gas phase inlet of the pyrolysis tower. The gas phase outlet of the pyrolysis tower is connected to the reaction tail gas condensation and recovery system, and the bottom liquid outlet of the pyrolysis tower is connected to a reaction liquid recovery tank. Before the reaction, the reaction system is heated and evacuated to remove water, then nitrogen is introduced and the pressure is maintained before cooling to room temperature.
[0131] The reactants are added to the feedstock tank. Before the reaction begins, a certain amount of liquid feedstock is added to the pyrolysis reactor via a metering valve until the liquid level in the pyrolysis reactor reaches the target value. Then, the liquid feedstock is sent from the liquid outlet at the bottom of the pyrolysis reactor to the liquid distributor at the top of the pyrolysis tower via a metering valve. After being evenly distributed, it forms a uniform liquid film on the surface of the packing material in the pyrolysis tower and flows downward. Finally, the reaction liquid flows out from the liquid outlet at the bottom of the pyrolysis tower and enters the reaction liquid recovery tank.
[0132] The pyrolysis reactor is started with stirring and heating.
[0133] The pyrolysis tower reactor is heated to a higher temperature.
[0134] The ozone-oxygen mixture and the feed gas are introduced into the reactor from the gas phase inlet at the bottom of the pyrolysis reactor, flowing upwards and reacting with the liquid inside the reactor. The gas flow rate is controlled by a mass flow meter.
[0135] The reaction tail gas exiting the gas phase outlet of the pyrolysis reactor flows into the gas phase inlet at the bottom of the pyrolysis tower, flows upward, and reacts with the liquid inside the tower.
[0136] Finally, the gaseous products from the final reaction are discharged from the top gaseous outlet of the cracking tower along with excess oxygen, and proceed to the next process. The reaction liquid enters the reaction liquid recovery tank from the bottom liquid outlet of the cracking tower. The reaction liquid in the recovery tank is either directly sent to the raw material batching tank for recycling or treated before being sent to the raw material batching tank for recycling.
[0137] The preferred gas-liquid contact time in the pyrolysis reactor is 1 to 25 minutes; the preferred temperature is 30 to 50°C; and the preferred inlet pressure is 0.15 to 0.25 MPa.
[0138] The preferred gas-liquid contact time in the pyrolysis tower is 1 to 15 minutes; the preferred temperature is 30 to 50°C; and the preferred inlet pressure is 0.15 to 0.25 MPa.
[0139] In this invention, when the perfluoroolefin is liquid, the reactants and solvent are mixed and added to the pyrolysis reactor, where they react with an ozone-oxygen mixture. The gaseous products of the reaction are discharged from the reactor with excess oxygen and proceed to the next step.
[0140] In some specific embodiments of the present invention, the liquid reaction feedstock is perfluoro-4-methyl-2-pentene, and the solvent is trifluoroacetic acid. Perfluoro-4-methyl-2-pentene and trifluoroacetic acid are added to the feedstock mixing tank and mixed thoroughly. Before the reaction begins, the mixture of perfluoro-4-methyl-2-pentene and trifluoroacetic acid is fed from the mixing tank into the cracking reactor via a metering valve until the material in the cracking reactor reaches the target liquid level. Then, the liquid feedstock is sent from the liquid outlet at the bottom of the cracking reactor to the liquid distributor at the top of the cracking tower via a metering valve. After being evenly distributed, a uniform liquid film forms on the surface of the packing material in the cracking tower and flows downwards. The cracking reactor is stirred, heated, and the cracking tower reactor is heated.
[0141] An ozone-oxygen mixture is generated using an ozone generator. This mixture enters the reactor through a gas-phase inlet at the top of the pyrolysis vessel, where it contacts and reacts with the liquid.
[0142] The reaction tail gas exiting the gas phase outlet of the pyrolysis reactor flows into the gas phase inlet at the bottom of the pyrolysis tower, flows upward, and reacts with the liquid inside the tower.
[0143] Finally, the gaseous products from the final reaction are discharged from the top gaseous outlet of the cracking tower along with excess oxygen, and proceed to the next process.
[0144] The reaction liquid is discharged through the bottom liquid outlet as needed to maintain the stability of the composition and liquid level within the reaction tower. The reaction liquid in the recovery tank is either directly sent to the raw material batching tank for recycling or treated before being sent to the raw material batching tank for recycling.
[0145] In this invention, when the perfluoroolefin is a gas, the solvent is added to the pyrolysis reactor. The gaseous reactants are introduced into the pyrolysis reactor in gaseous form to mix with the solvent and react with the ozone-oxygen mixture. The gaseous products of the reaction are discharged from the reactor with excess oxygen and enter the next process.
[0146] In some specific embodiments of the present invention, the gaseous reaction feedstock is hexafluoropropylene gas, and the solvent is trifluoroacetic acid. Trifluoroacetic acid is added to the feedstock mixing tank. Before the reaction begins, trifluoroacetic acid is fed from the mixing tank into the pyrolysis reactor via a metering valve until the material in the pyrolysis reactor reaches the target liquid level. Then, the liquid feedstock is sent from the liquid outlet at the bottom of the pyrolysis reactor to the liquid distributor at the top of the pyrolysis tower via a metering valve. After being evenly distributed, a uniform liquid film forms on the surface of the packing material in the pyrolysis tower and flows downwards. The pyrolysis reactor is stirred, heated, and the pyrolysis tower is heated.
[0147] An ozone-oxygen mixture is generated using an ozone generator. This mixture enters the reactor through a gas-phase inlet at the top of the pyrolysis vessel, where it contacts and reacts with the liquid.
[0148] The reaction tail gas exiting the gas phase outlet of the pyrolysis reactor flows into the gas phase inlet at the bottom of the pyrolysis tower, flows upward, and reacts with the liquid inside the tower.
[0149] Finally, the gaseous products from the final reaction are discharged from the top gaseous outlet of the cracking tower along with excess oxygen, and proceed to the next process.
[0150] The reaction liquid is discharged through the bottom liquid outlet as needed to maintain the stability of the composition and liquid level within the reaction tower. The reaction liquid in the recovery tank is either directly sent to the raw material batching tank for recycling or treated before being sent to the raw material batching tank for recycling.
[0151] The inlet velocity of the gaseous reaction raw material is preferably 1~200 SCCM, more preferably 1~100 SCCM; the inlet velocity of the ozone-oxygen mixed gas is preferably 10~500 SCCM, more preferably 50~200 SCCM.
[0152] While pyrolysis reactors can achieve an ideal balance between temperature control and mass transfer interface, and offer the best control over liquid phase composition homogeneity, especially with high gas uptake rate, gas content, gas-liquid volumetric mass transfer coefficient, and gas-liquid interface achieved through self-aspirating stirring, the process requires high-intensity dispersion and stirring, resulting in high stirring power, much of which is converted into heat energy, placing high demands on system heat transfer and complicating equipment structure. Using a pyrolysis reactor alone leads to excessively high energy consumption. While pyrolysis towers can control the gas-liquid flow state within the tower by adjusting the gas and liquid phase flow rates, thus achieving a larger gas-liquid mass transfer interface and a higher gas-liquid volumetric mass transfer coefficient, they are not conducive to temperature control, and the lack of liquid phase stirring results in lower composition homogeneity control compared to pyrolysis reactors. This invention uses a pyrolysis reactor and a pyrolysis tower connected in series as a pyrolysis reactor, overcoming the shortcomings of single-reaction equipment and achieving higher feed conversion rate, better reaction control (low by-products), and lower energy consumption.
[0153] In some specific embodiments of the present invention, the pyrolysis reactor is a falling film reactor, a pyrolysis vessel, and a pyrolysis tower connected in sequence. For example... Figure 6 As shown.
[0154] The falling film reactor, pyrolysis vessel, and pyrolysis tower are connected in series, wherein the falling film reactor is connected to the raw material batching tank.
[0155] The lower end of the falling film reactor is provided with an air inlet for the oxygen-ozone mixture and the reaction raw material gas to enter.
[0156] The falling film reactor is equipped with a liquid inlet at the top for the liquid reaction raw materials to enter.
[0157] The lower end of the falling film reactor is also provided with a liquid outlet, which is connected to the liquid inlet at the top of the pyrolysis vessel.
[0158] The falling film reactor is provided with a gas outlet at the top, which is connected to the gas inlet at the top of the pyrolysis vessel.
[0159] The bottom of the pyrolysis vessel is provided with a liquid outlet, which is connected to the liquid inlet at the top of the pyrolysis tower.
[0160] The top of the pyrolysis vessel is also provided with a gas outlet, which is connected to the gas inlet at the bottom of the pyrolysis tower.
[0161] The top of the pyrolysis tower is equipped with a gas outlet for the escape of gaseous products during the reaction process.
[0162] The pyrolysis tower is equipped with a liquid outlet at the bottom for discharging the reaction liquid.
[0163] The setup and parameters of the falling film reactor, pyrolysis vessel, and pyrolysis tower are as described above and will not be repeated here.
[0164] Preferably, the pyrolysis reactions in the falling film reactor, pyrolysis vessel, and pyrolysis tower reactor are as follows:
[0165] The falling film reactor is connected to the raw material mixing tank, and its bottom liquid outlet is connected to the liquid phase inlet of the pyrolysis reactor. The gas inlet of the falling film reactor is connected to ozone and the gaseous raw material, and its outlet is connected to the gas phase inlet of the pyrolysis reactor. The gas phase outlet of the pyrolysis reactor is connected to the gas phase inlet of the pyrolysis tower. The liquid phase outlet of the pyrolysis reactor is connected to the liquid phase inlet of the pyrolysis tower. The gas phase outlet of the pyrolysis tower is connected to the reaction tail gas condensation and recovery system, and the bottom liquid outlet of the pyrolysis tower is connected to a reaction liquid recovery tank. Before the reaction, the reaction system is heated and evacuated to remove water, then nitrogen is introduced and the pressure is maintained before cooling to room temperature.
[0166] Liquid reactants are added to the feed tank. The liquid feedstock flows uniformly from the feed tank through a metering valve into the liquid distributor at the top of the falling film reactor. After being evenly distributed, a liquid film forms on the inner wall of the falling film reactor and flows downwards. Then, the liquid reactants flow out from the liquid outlet at the bottom of the falling film reactor and into the pyrolysis reactor through a metering valve until the liquid level in the pyrolysis reactor reaches the target value. The liquid reactants in the pyrolysis reactor then flow uniformly through a metering valve into the liquid distributor at the top of the pyrolysis tower. After being evenly distributed, a liquid film forms on the surface of the pyrolysis tower packing and flows downwards, finally flowing out from the liquid outlet at the bottom of the pyrolysis tower and entering the reaction liquid recovery tank.
[0167] The falling film reactor is heated to a higher temperature.
[0168] The pyrolysis reactor is started with stirring and heating.
[0169] The pyrolysis tower reactor is heated to a higher temperature.
[0170] The ozone-oxygen mixture and the feed gas are introduced into the falling film reactor through the gas phase inlet at the bottom, flowing upwards to react with the liquid film. The gas flow rate is controlled by a mass flow meter.
[0171] In the falling film reactor, the gaseous mixture containing pyrolysis products flows out from the gas phase outlet at the top of the reactor and enters the pyrolysis vessel through the gas phase feed inlet. The gas and liquid phases then react in contact within the pyrolysis vessel.
[0172] The gaseous material containing reaction products, exiting from the gas phase outlet of the pyrolysis reactor, flows upward into the gas phase inlet at the bottom of the pyrolysis tower. The gas and liquid react in contact within the pyrolysis tower.
[0173] Finally, the gaseous products in the pyrolysis tower are discharged from the top gas phase outlet along with excess oxygen and enter the next process; the reaction liquid containing liquid raw materials in the pyrolysis tower is discharged through the bottom phase outlet and enters the reaction liquid recovery tank. The reaction liquid in the recovery tank is either directly sent to the raw material batching tank for recycling or treated before being sent to the raw material batching tank for recycling.
[0174] The gas-liquid contact time in the falling film reactor is 1 to 10 minutes; the temperature is preferably 30 to 50°C; and the inlet pressure is preferably 0.15 to 0.25 MPa.
[0175] The preferred gas-liquid contact time in the pyrolysis reactor is 1 to 25 minutes; the preferred temperature is 30 to 50°C; and the preferred inlet pressure is 0.15 to 0.25 MPa.
[0176] The preferred gas-liquid contact time in the pyrolysis tower is 1 to 15 minutes; the preferred temperature is 30 to 50°C; and the preferred inlet pressure is 0.15 to 0.25 MPa.
[0177] In this invention, when the perfluoroolefin is liquid, the reactants and solvent are mixed and added to the pyrolysis reactor, where they react with an ozone-oxygen mixture. The gaseous products of the reaction are discharged from the reactor with excess oxygen and proceed to the next step.
[0178] In some specific embodiments of the present invention, the liquid reaction feedstock is perfluoro-4-methyl-2-pentene, and the solvent is trifluoroacetic acid. Perfluoro-4-methyl-2-pentene and trifluoroacetic acid are added to the feedstock mixing tank, mixed evenly, and then flowed at a constant speed from the feedstock mixing tank into the liquid phase distributor at the top of the falling film reactor through a metering valve. After even distribution, a liquid film forms on the inner wall of the falling film reactor and flows downwards. Then, the liquid reaction feedstock flows out from the liquid outlet at the bottom of the falling film reactor and flows into the pyrolysis reactor through the liquid inlet through a metering valve until the liquid level in the pyrolysis reactor reaches the target value. Then, the liquid reaction feedstock in the pyrolysis reactor flows at a constant speed into the liquid phase distributor at the top of the pyrolysis tower through a metering valve. After even distribution, a liquid film forms on the surface of the pyrolysis tower packing and flows downwards, finally flowing out from the liquid outlet at the bottom of the pyrolysis tower and entering the reaction liquid recovery tank.
[0179] The falling film reactor is heated to a higher temperature, the pyrolysis vessel is stirred and heated to a higher temperature, and the pyrolysis tower reactor is heated to a higher temperature.
[0180] An ozone-oxygen mixture is generated using an ozone generator. This mixture enters the falling film reactor through a gas-phase inlet at the bottom, flows upwards, and reacts with the liquid.
[0181] In the membrane reactor, the gaseous mixture containing the reaction products flows out from the gas phase outlet at the top of the reactor and enters the pyrolysis reactor through the gas phase feed inlet. The gas and liquid phases then react in contact within the pyrolysis reactor.
[0182] The gaseous material containing reaction products, exiting from the gas phase outlet of the pyrolysis reactor, flows upward into the gas phase inlet at the bottom of the pyrolysis tower. The gas and liquid react in contact within the pyrolysis tower.
[0183] Finally, the gaseous products in the pyrolysis tower are discharged from the top gas phase outlet along with excess oxygen and enter the next process; the reaction liquid containing liquid raw materials in the pyrolysis tower is discharged through the bottom phase outlet and enters the reaction liquid recovery tank. The reaction liquid in the recovery tank is either directly sent to the raw material batching tank for recycling or treated before being sent to the raw material batching tank for recycling.
[0184] In this invention, when the perfluoroolefin is in the form of a gas, the solvent is added to the pyrolysis reactor, the reactants are introduced into the pyrolysis reactor in gaseous form and mixed with the solvent, and react with the ozone-oxygen mixture. The gaseous products of the reaction are discharged from the reactor with excess oxygen and enter the next process.
[0185] In some specific embodiments of the present invention, the gaseous reactant is hexafluoropropylene gas, and the solvent is trifluoroacetic acid. Trifluoroacetic acid is added to the raw material mixing tank. The liquid raw material flows uniformly from the raw material mixing tank into the liquid phase distributor at the top of the falling film reactor via a metering valve. After uniform distribution, a liquid film forms on the inner wall of the falling film reactor and flows downwards. Then, the liquid reactant flows out from the liquid outlet at the bottom of the falling film reactor and flows into the pyrolysis reactor through the liquid inlet via a metering valve until the liquid level in the pyrolysis reactor reaches the target value. The liquid reactant in the pyrolysis reactor then flows uniformly into the liquid phase distributor at the top of the pyrolysis tower via a metering valve. After uniform distribution, a liquid film forms on the surface of the pyrolysis tower packing and flows downwards, finally flowing out from the liquid outlet at the bottom of the pyrolysis tower and entering the reaction liquid recovery tank.
[0186] The falling film reactor is heated to a higher temperature, the pyrolysis vessel is stirred and heated to a higher temperature, and the pyrolysis tower reactor is heated to a higher temperature.
[0187] An ozone-oxygen mixture is generated using an ozone generator. The ozone-oxygen mixture, along with hexafluoropropylene, enters the reactor from the gas phase inlet at the bottom of the falling film reactor, where it comes into contact with the liquid and undergoes an oxidative cracking reaction.
[0188] In the falling film reactor, the gaseous mixture containing the reaction products flows out from the gas phase outlet at the top of the reactor and enters the pyrolysis reactor through the gas phase feed inlet. The gas and liquid phases then react in contact within the pyrolysis reactor.
[0189] The gaseous material containing reaction products, exiting from the gas phase outlet of the pyrolysis reactor, flows upward into the gas phase inlet at the bottom of the pyrolysis tower. The gas and liquid react in contact within the pyrolysis tower.
[0190] Finally, the gaseous products in the pyrolysis tower are discharged from the top gas phase outlet along with excess oxygen and enter the next process; the reaction liquid containing liquid raw materials in the pyrolysis tower is discharged through the bottom phase outlet and enters the reaction liquid recovery tank. The reaction liquid in the recovery tank is either directly sent to the raw material batching tank for recycling or treated before being sent to the raw material batching tank for recycling.
[0191] The inlet velocity of the gaseous reaction raw material is preferably 1~200 SCCM, more preferably 1~100 SCCM; the inlet velocity of the ozone-oxygen mixed gas is preferably 10~500 SCCM, more preferably 50~200 SCCM.
[0192] As is well known, falling film reactors, pyrolysis vessels, and pyrolysis towers each have their own advantages and disadvantages. Falling film reactors are advantageous for temperature control, but their gas-liquid mass transfer interface is relatively small, and the liquid phase material lacks mixing, resulting in poor compositional uniformity. Pyrolysis towers can achieve a larger gas-liquid mass transfer interface and a higher gas-liquid volumetric mass transfer coefficient by adjusting the gas and liquid phase flow rates, but they are not conducive to temperature control, and the control of liquid phase composition is not as good as that of pyrolysis vessels. Pyrolysis vessels can achieve an ideal balance between temperature control and mass transfer interface, and have the best control over liquid phase composition. In particular, high gas absorption rate, gas content, gas-liquid volumetric mass transfer coefficient, and gas-liquid interface can be obtained through self-priming stirring. However, the process requires high-intensity dispersion and stirring, with high stirring power, most of which is converted into heat energy, placing high demands on system heat transfer, and the equipment structure is complex, resulting in high energy consumption during production.
[0193] No single reaction device can achieve ideal results. This invention optimizes the structural design of the three types of reactors and optimizes their combination and connection to achieve a safe, efficient, and highly selective acyl fluoride production process.
[0194] Furthermore, the pyrolysis products are selectively absorbed by an absorbent and / or recovered, separated, and purified by cryogenic condensation. The selective absorption and / or cryogenic condensation recovery equipment, separation equipment, and purification equipment preferably include:
[0195] Equipment such as acyl fluoride absorption systems, cryogenic condensation systems, acyl fluoride storage tanks, acyl fluoride crude fractionation towers, and distillation towers.
[0196] The acyl fluoride absorption system is used to selectively absorb specific components in an acyl fluoride mixture. Preferably, the acyl fluoride absorption system consists of an absorption tank and / or an absorption tower.
[0197] The cryogenic condensation system is used to condense and collect acyl fluoride products. Preferably, the cryogenic condensation system consists of a cryogenic condenser and a receiving tank.
[0198] The acyl fluoride storage tank is used to store the collected acyl fluoride mixture.
[0199] The crude acyl fluoride separation tower is used to crudely separate the collected acyl fluoride mixture to obtain crude acyl fluoride products.
[0200] The distillation column is used to distill crude acyl fluoride to obtain the product.
[0201] More preferably, the product selective absorption and / or cryogenic condensation recovery equipment, separation equipment, and purification equipment include:
[0202] Selective absorption tank, reflux condenser, acyl fluoride collection tank, acyl fluoride crude fractionation column and distillation column are connected in series.
[0203] The preferred methods for selective absorption of the pyrolysis products by an absorbent and / or low-temperature condensation recovery, separation, and purification include:
[0204] 1) The reaction products are passed into a selective absorption tank to absorb specific reaction products and / or passed into a low-temperature condenser to condense and recover the acyl fluoride mixture, which is then placed in an acyl fluoride collection tank; 2) The acyl fluoride mixture is fed into an acyl fluoride crude separation tower to obtain crude acyl fluoride; 3) The crude acyl fluoride is fed into a distillation tower to obtain the product.
[0205] The product selective absorption device, such as a selective absorption tank, contains a selective absorbent for selective absorption of the reaction product, and / or a non-selective absorbent is added.
[0206] The selective absorption refers to the separation and collection of crude products using a selective absorbent. For example, a mixture of pentafluoropropionyl fluoride and hexafluoroacetone. Since the boiling points of pentafluoropropionyl fluoride and hexafluoroacetone are very close (-26.5℃ and -28℃ respectively), they are difficult to separate by distillation. The mixture can be passed into an absorption tank containing a selective absorbent to absorb the hexafluoroacetone, thereby separating the pentafluoropropionyl fluoride and hexafluoroacetone. Preferably, the selective absorbent is anhydrous hydrogen fluoride.
[0207] Preferably, the temperature during the selective absorption process is -100℃ to 0℃, more preferably -80℃ to 0℃, even more preferably -60℃ to 0℃, and even more preferably -50℃ to 0℃.
[0208] Preferably, the pressure of the selective absorption process is the pressure of the ozone decomposition reaction described above, which is 1 to 10 kg; more preferably, it is 1 to 8 kg, and even more preferably, it is 1 to 6 kg.
[0209] The low-temperature condensation recovery refers to passing the reaction products into a condenser, causing the acyl fluoride mixture to condense and be collected.
[0210] Preferably, the temperature during the condensation process is -100℃ to 0℃, more preferably -80℃ to 0℃, even more preferably -60℃ to 0℃, and even more preferably -50℃ to 0℃.
[0211] The pressure during the condensation process is the pressure of the ozone decomposition reaction described above, preferably 1 to 10 kg; more preferably 1 to 8 kg, and even more preferably 1 to 6 kg.
[0212] The separation refers to the crude separation of the acyl fluoride mixture into individual crude acyl fluoride products by distillation or rectification. The distillation or rectification is preferably atmospheric distillation or rectification, and more preferably pressure distillation or rectification.
[0213] Preferably, the pressure of the pressurized distillation or rectification is 1 to 50 kg; more preferably 1 to 30 kg, and even more preferably 1 to 20 kg.
[0214] Preferably, the temperature of the pressure distillation or rectification is -50℃ to 100℃, the reflux ratio of the rectification separation is 10:1 to 0.1:1, and the temperature of the condenser is -50℃ to 0℃.
[0215] The separation can be performed intermittently or continuously.
[0216] The purification refers to purifying the crude acyl fluoride product into an acyl fluoride product through distillation. The distillation is preferably atmospheric distillation, and more preferably pressurized distillation.
[0217] The preferred temperature for the distillation separation is -100℃ to 100℃, the preferred pressure for the distillation separation is 0 to 20 kg, and the preferred reflux ratio for the distillation separation is 10:1 to 0.1:1. The preferred temperature for the condenser is -50℃ to 0℃.
[0218] In this invention, when the boiling points of the reaction products differ significantly, the mixed products are collected using a low-temperature collection tank (-120~0℃) and a condenser. Then, crude fractionation of each component is achieved through distillation or rectification. These crude fractions are further purified by rectification to obtain high-purity product components. When the products contain components with very similar boiling points, the product gas stream first passes through a selective absorbent to absorb specific products. After processing and rectification, high-purity specific products are obtained. The remaining product gas stream is then collected using a low-temperature collection tank (-120~0℃) and a condenser to collect other mixed products. Crude fractionation of each component is then achieved through distillation or rectification. These crude fractions are further purified by rectification to obtain high-purity product components. For example, when cracking perfluoro-2-methyl-2-pentene, anhydrous hydrogen fluoride is used as a selective absorbent to absorb hexafluoroacetone. After selective absorption, the remaining acyl fluoride mixture (trifluoroacetyl fluoride, trifluoromethyl fluoroformate, and pentafluoropropionyl fluoride) is condensed in an ultra-low temperature condenser below -100°C and stored in a cryogenic storage tank below -100°C. The collected acyl fluoride mixture is first crudely separated to obtain crude products of each component, and then further purified by distillation to obtain high-purity products of each component.
[0219] Furthermore, this application further obtains other products from the residual tail gas through absorption, separation, and purification.
[0220] The tail gas absorption, separation and purification equipment includes: a tail gas absorption system, a mixed ester extraction tower, a drying tower, a mixed ester crude fractionation tower and a distillation tower, etc.
[0221] The tail gas absorption is completed in a tail gas absorption system consisting of an absorption tower and an absorbent circulation tank. The tail gas absorption system is equipped with an absorbent, which can be used to absorb byproducts such as acyl fluoride in the tail gas.
[0222] The tail gas absorption is completed in a tail gas absorption system consisting of an absorption tower and an absorbent circulation tank. The tail gas absorption system is equipped with a non-selective absorbent, which can absorb byproducts such as acyl fluoride in the tail gas.
[0223] The non-selective absorbent is preferably a C1-C5 aliphatic alcohol, more preferably methanol or ethanol. When an ethanol absorbent is used, the ethanol reacts with all acyl fluorides to produce esters and hydrogen fluoride.
[0224] Preferably, the temperature during the absorption process is -60℃ to 25℃, more preferably -50℃ to 15℃, and even more preferably -40℃ to 5℃.
[0225] Preferably, the pressure during the absorption process is 1 to 10 kg; more preferably 1 to 8 kg, and even more preferably 1 to 6 kg.
[0226] After the absorption process is completed, the resulting mixed ester product contains HF, which is removed by extraction.
[0227] Preferably, the extraction process uses deionized water.
[0228] Preferably, the extraction process temperature is -30℃ to 10℃, more preferably -30℃ to 0℃.
[0229] Preferably, the extraction process involves multi-stage counter-current contact extraction of the absorbent and deionized water in an extraction tower. The aqueous layer after extraction is an aqueous solution of hydrogen fluoride, and the intermediate layer is a mixture of esters, including ethyl fluoroformate, ethyl trifluoroacetate, ethyl pentafluoropropionate, ethyl heptafluoroisobutyrate, ethyl heptafluoron-butyrate, and diethyl carbonate, etc.
[0230] The mixed ester needs to be dried before further separation and purification to remove residual moisture.
[0231] The mixed esters are first separated into crude products of different esters by a crude separation column, and then purified by a distillation column to obtain fluoroester products.
[0232] This application also provides a method for preparing fluorine-containing intermediates by ozone cracking using the above-mentioned equipment and perfluoroolefins as raw materials, comprising the following steps:
[0233] A) Perfluoroolefins are subjected to ozonolysis in a pyrolysis unit with an oxygen-ozone mixture to obtain the product;
[0234] B) The product is selectively absorbed by an absorbent and / or recovered, separated and purified by low-temperature condensation to obtain a fluorine-containing intermediate;
[0235] C) The residual tail gas is further absorbed, separated and purified by an absorbent to obtain other products.
[0236] Step A) The perfluoroolefin and oxygen-ozone mixture undergo ozonolysis in a reactor to obtain the product specifically refers to: 1) When the perfluoroolefin is liquid, the reactants, solvent, and regulator are mixed and added to the pyrolysis reactor, where they react with the ozone-ozone mixture. The gaseous product is discharged from the reactor with excess oxygen and proceeds to the next step; or 2) When the perfluoroolefin is gaseous, the solvent and regulator are mixed and added to the pyrolysis reactor. The gaseous reactants are introduced into the reactor in gaseous form and mixed with the solvent and regulator, and react with the ozone-ozone mixture. The gaseous product is discharged from the reactor with excess oxygen and proceeds to the next step.
[0237] The equipment provided in this application is suitable for the ozonochemical cracking reaction of perfluoroolefins with oxygen-ozone mixture, and the cracking products vary depending on the raw materials.
[0238] The perfluoroolefin is preferably a perfluoroolefin compound with 2-8 carbon atoms, specifically a perfluoroolefin compound with 2, 3, 4, 5, 6, 7 or 8 carbon atoms. The perfluoroolefin compound includes, but is not limited to, straight-chain, branched, cyclic monoolefins and / or polyolefins, etc., and the polyolefin is preferably a diene.
[0239] In some specific embodiments of this application, the two-carbon perfluoroolefins include, but are not limited to, tetrafluoroethylene (CF2=CF2).
[0240] In some specific embodiments of this application, the three-carbon perfluoroolefins include, but are not limited to, one or more of hexafluoropropylene (CF3CF=CF2), perfluorocyclopropylene, etc.
[0241] The perfluorocyclopropylene structure is as follows:
[0242]
[0243] The perfluoroolefin with 4 to 8 carbon atoms is preferably a tetrafluoroethylene oligomer, a hexafluoropropylene oligomer, a copolymer of tetrafluoroethylene and hexafluoropropylene, or a perfluoroolefin obtained by other disclosed technical routes.
[0244] The copolymer of tetrafluoroethylene and hexafluoropropylene is preferably a copolymer with a low degree of polymerization.
[0245] In some specific embodiments of this application, the four-carbon perfluoroolefins include, but are not limited to:
[0246] Perfluoro-1-butene (CF3CF2CF=CF2);
[0247] Perfluoro-1-isobutene ((CF3)2CF=CF2);
[0248] Perfluoro-2-butene (CF3CF=CFCF3);
[0249] Perfluorocyclobutene:
[0250]
[0251] Perfluorobutadiene (CF2=CF-CF=CF2).
[0252] The five-carbon perfluoroolefins include, but are not limited to:
[0253] Perfluoro-1-pentene (CF2=CFCF2CF2CF3);
[0254] Perfluoro-2-pentene (CF3CF=CFCF2CF3);
[0255] Perfluorocyclopentene:
[0256]
[0257] Perfluoro-1,4-pentadiene (CF2=CFCF2CF=CF2).
[0258] The six-carbon perfluoroolefins include, but are not limited to:
[0259] Perfluoro-2-methyl-2-pentene (CF3(CF3)C=CFCF2CF3);
[0260] Perfluoro-4-methyl-2-pentene (CF3CF(CF3)CF=CFCF3);
[0261] Perfluoro-1,5-hexadiene (CF2=CFCF2CF2CF=CF2).
[0262] The perfluoroolefins with 7 carbon atoms include, but are not limited to:
[0263] Perfluoro-3-hepten (CF3CF2CF=CFCF2CF2CF3);
[0264] Perfluoro-2-methyl-2-hexene (CF3CF2CF2CF=C(CF3)CF3).
[0265] The olefins with 8 carbon atoms include, but are not limited to:
[0266] Perfluoro-3,4-dimethyl-3-hexene (CF3CF2(CF3)C=C(CF3)CF2CF3).
[0267] This application uses perfluoroolefins as raw materials and carries out ozone cracking reactions to prepare a series of fluorine-containing intermediates with important applications, such as carbonyl fluoride, trifluoroacetyl fluoride, trifluoromethyl fluoroformate, pentafluoropropionyl fluoride, hexafluoroacetone, heptafluoroisobutyryl fluoride, heptafluoron-butyryl fluoride, and perfluoro-1,4-succinyl fluoride.
[0268] In some specific embodiments of this application, the raw material is tetrafluoroethylene, and the cracking product is mainly carbonyl fluoride.
[0269] In some specific embodiments of this application, the raw material is hexafluoropropylene, and the cracking products are mainly carbonyl fluoride, trifluoroacetyl fluoride and trifluoromethyl fluoroformate.
[0270] In some specific embodiments of this application, the raw material is perfluorocyclopropylene, and the cracking product is mainly perfluoromalonyl fluoride.
[0271] In some specific embodiments of this application, the raw material is perfluoro-1-butene, and the cracking products are mainly carbonyl fluoride, pentafluoropropionyl fluoride and trifluoromethyl fluoroformate.
[0272] In some specific embodiments of this application, the raw material is perfluoro-2-butene, and the cracking products are mainly trifluoroacetyl fluoride and trifluoromethyl fluoroformate.
[0273] In some specific embodiments of this application, the raw material is perfluoro-1-isobutylene, and the cracking products are mainly carbonyl fluoride, hexafluoroacetone and trifluoromethyl fluoroformate.
[0274] In some specific embodiments of this application, the raw material is perfluorocyclobutene, and the cracking product is mainly perfluoro-1,4-succinyl fluoride.
[0275] In some specific embodiments of this application, the raw material is perfluoro-1-pentene, and the cracking products are mainly heptafluorobutyryl fluoride, carbamate fluoride, and trifluoromethyl fluoroformate.
[0276] In some specific embodiments of this application, the raw material is perfluoro-2-pentene, and the cracking products are mainly trifluoroacetyl fluoride, pentafluoropropionyl fluoride and trifluoromethyl fluoroformate.
[0277] In some specific embodiments of this application, the raw material is perfluorocyclopentene, and the cracking product is mainly perfluoro-1,5-glutaryl fluoride.
[0278] In some specific embodiments of this application, the raw material is perfluoro-2-methyl-1-butene, and the cracking products are mainly carbonyl fluoride and perfluorobutanone.
[0279] In some specific embodiments of this application, the raw material is perfluoro-2-methyl-2-butene, and the cracking products are mainly trifluoromethyl fluoroformate, trifluoroacetyl fluoride and hexafluoroacetone.
[0280] In some specific embodiments of this application, the raw material is perfluoro-3-methyl-1-butene, and the cracking products are mainly carbonyl fluoride and perfluoro-2-methylpropionyl fluoride.
[0281] In some specific embodiments of this application, the raw material is perfluoro-4-methyl-2-pentene, and the cracking products are mainly heptafluoroisobutyryl fluoride, trifluoromethyl fluoroformate, and trifluoroacetyl fluoride.
[0282] In some specific embodiments of this application, the raw material is perfluoro-2-methyl-2-pentene, and the cracking products are mainly hexafluoroacetone, pentafluoropropionyl fluoride, trifluoromethyl fluoroformate and trifluoroacetyl fluoride.
[0283] In some specific embodiments of this application, the raw material is perfluoro-1,5-hexadiene (CF2=CFCF2CF2CF=CF2), and the cracking products are mainly carbonyl fluoride, perfluoro-4-en-pentanoyl fluoride and perfluorosuccinyl fluoride.
[0284] In some specific embodiments of this application, the raw material is perfluoro-3-heptene (CF3CF2CF=CFCF2CF2CF3), and the cracking products are mainly perfluoropropionyl fluoride and perfluoron-butyryl fluoride.
[0285] In some specific embodiments of this application, the raw material is perfluoro-2-methyl-2-hexene (CF3CF2CF2CF=C(CF3)CF3), and the cracking products are mainly hexafluoroacetone and perfluorobutyryl fluoride.
[0286] In some specific embodiments of this application, the raw material is perfluoro-3,4-dimethyl-3-hexene (CF3CF2(CF3)C=C(CF3)CF2CF3), and the cracking product is mainly perfluorobutanone.
[0287] This application uses an ozone-oxygen mixture in the ozone decomposition reaction process, wherein the ozone concentration is preferably 1% to 50% (volume concentration). In some specific embodiments of this application, the ozone concentration in the aforementioned oxygen-ozone mixture is approximately 100 mg / L.
[0288] Preferably, the molar ratio of the perfluoroolefin to the consumed ozone is 1:(0.2~8), more preferably 1:(0.2~3).
[0289] The preferred temperature for the ozone decomposition reaction is -100℃ to 100℃, more preferably -80℃ to 80℃, even more preferably -60℃ to 60℃, and even more preferably -50℃ to 50℃. In some specific embodiments of this application, the temperature for the ozone decomposition reaction is -50℃, -45℃, -40℃, -20℃, 0℃, 25℃, 40℃, 50℃, 60℃, or 70℃, or any of the above values as the upper or lower limit.
[0290] The pressure of the above-mentioned ozone decomposition reaction is preferably 1 to 10 kg; more preferably 1 to 8 kg, and even more preferably 1 to 6 kg.
[0291] In the above ozone decomposition reaction, solvent raw materials can be added for dilution as needed, or perfluoroolefins can be directly decomposed. The solvent used is preferably a fluorocarbon solvent, which is preferably one or more of fluorinated hydrocarbons, fluorocarbon esters, hydrofluoroethers, and perfluoropolyethers. The fluorinated hydrocarbon is preferably CFC-113, the fluorocarbon ester is preferably ethyl trifluoroacetate, the hydrofluoroether is preferably Novec 7100, 7200, or 7500, and the perfluoropolyether is preferably Krytox GPL101, etc. The mass ratio of the solvent to the perfluoroolefin is preferably (0:100) to (80:20).
[0292] In the above-mentioned ozone decomposition reaction, a reaction regulator can be added as needed to dilute the raw materials and control the composition of the products. The reaction regulator is a proton-containing compound, preferably including alcohols and / or acidic compounds. Preferably, the reaction regulator is one or more of fluorocarbonic acid and fluorocarbon alcohols. More preferably, the fluorocarbonic acid includes one or more of trifluoroacetic acid, pentafluoropropionic acid, and heptafluoroisobutyric acid, and the fluorocarbon alcohol includes one or more of trifluoroethanol, tetrafluoropropanol, pentafluoropropanol, hexafluoroisopropanol, and octafluoropentanol. The mass ratio of the reaction regulator to the perfluoroolefin is preferably (0:100) to (80:20).
[0293] The above-mentioned ozone cracking reaction can be carried out in batch or continuous operation. The batch operation is preferably as follows: perfluoroolefins, fluorocarbon solvents, and reaction regulators are added to the cracking equipment all at once, and then an ozone-oxygen mixture is continuously introduced at a set temperature for cracking until the perfluoroolefins are completely cracked. The continuous operation is preferably as follows: perfluoroolefins, fluorocarbon solvents, and reaction regulators are first mixed in a certain proportion, then a portion of the mixture is added to the cracking equipment all at once, and then an ozone-oxygen mixture is continuously introduced at a set temperature for cracking, while the mixture is continuously added to the cracking reactor at a certain rate during the process.
[0294] The ozone decomposition reaction described above has no special limitations on the reaction time. Preferably, for batch operation, the reaction can generally be stopped after the substrate has been completely decomposed; for continuous operation, the reaction can be stopped at any time according to the actual needs of the reaction.
[0295] In some specific embodiments of this application, when the raw material is tetrafluoroethylene, the cracking product is mainly carbonyl fluoride. The product is condensed in an ultra-low temperature condenser below -100°C and stored in a low temperature storage tank below -100°C. High-purity carbonyl fluoride can be obtained through further distillation.
[0296] In some specific embodiments of this application, when the raw material is hexafluoropropylene, the cracking products are mainly carbamate, trifluoroacetyl fluoride, and trifluoromethyl fluoroformate. The products are condensed in an ultra-low temperature condenser below -100°C and stored in a cryogenic storage tank below -100°C. Preferably, the condenser operates in a mode where the refrigerant and reaction products do not contact; more preferably, it operates in a mode where the refrigerant and reaction products directly contact. The refrigerant is preferably an inert fluorocarbon solvent such as perfluoroolefins, hydrofluorocarbons, hydrofluoroethers, and perfluoropolyethers. Because the boiling points of carbamate, trifluoroacetyl fluoride, and trifluoromethyl fluoroformate differ significantly (at -84°C, -59°C, and -35°C, respectively), the reaction products are easily separated. Typically, the acyl fluoride mixture is separated and purified by a process of first crude separation followed by distillation. Specifically, the acyl fluoride mixture is first crudely separated at -75°C to obtain carbamate, and then crudely separated at -50°C to obtain trifluoroacetyl fluoride. The crude acyl fluoride separated from the distillation process is further refined to obtain high-purity acyl fluoride products.
[0297] In some specific embodiments of this application, when the raw material is perfluorocyclopropylene, the cracking product is mainly perfluoromalonyl fluoride (boiling point -9°C). The product is condensed in a cryogenic condenser below -50°C, and the crude perfluoromalonyl fluoride is stored in a cryogenic storage tank below -50°C. Further distillation can yield high-purity perfluoromalonyl fluoride.
[0298] In some specific embodiments of this application, when the raw material is perfluoro-1-butene, the cracking products are mainly carbamate, pentafluoropropionyl fluoride, and trifluoromethyl fluoroformate. The products are condensed in an ultra-low temperature condenser below -100°C and stored in a cryogenic storage tank below -100°C. Preferably, the condenser operates in a mode where the refrigerant and reaction products do not contact; more preferably, it operates in a mode where the refrigerant and reaction products are in direct contact. The refrigerant is preferably an inert fluorocarbon solvent such as perfluoroolefins, hydrofluorocarbons, hydrofluoroethers, and perfluoropolyethers. Because the boiling points of carbamate, pentafluoropropionyl fluoride, and trifluoromethyl fluoroformate differ significantly (at -84°C, -26.5°C, and -35°C, respectively), the reaction products are easily separated. Typically, the acyl fluoride mixture is separated and purified by a process of first crude separation followed by distillation. Specifically, the acyl fluoride mixture is first crudely separated at -75°C to obtain carbamate; then, trifluoromethyl fluoroformate is crudely separated at -30°C. The crude acyl fluoride separated from the distillation process is further refined to obtain high-purity acyl fluoride products.
[0299] In some specific embodiments of this application, when the raw material is perfluoro-2-butene, the cracking products are mainly trifluoroacetyl fluoride and trifluoromethyl fluoroformate. The products are condensed in an ultra-low temperature condenser below -100°C, and the acyl fluoride mixture is stored in a cryogenic storage tank below -100°C. Preferably, the condenser operates in a mode where the refrigerant and reaction products do not contact; more preferably, it operates in a mode where the refrigerant and reaction products directly contact. The refrigerant is preferably an inert fluorocarbon solvent such as perfluoroolefins, hydrofluorocarbons, hydrofluoroethers, and perfluoropolyethers. Because the boiling points of trifluoroacetyl fluoride and trifluoromethyl fluoroformate differ significantly (at -59°C and -35°C, respectively), the reaction products are easily separated. Typically, the acyl fluoride mixture is separated and purified by a process of first crude separation followed by distillation. Specifically, the acyl fluoride mixture is first crudely separated at -50°C to obtain trifluorofluoride. The crudely separated acyl fluoride is further purified by distillation to obtain a high-purity acyl fluoride product.
[0300] In some specific embodiments of this application, when the raw material is perfluoro-1-isobutylene, the cracking products are mainly carbamate, hexafluoroacetone, and trifluoromethyl fluoroformate. The products are condensed in an ultra-low temperature condenser below -100°C, and the mixture of acyl fluoride and other products is stored in a cryogenic storage tank below -100°C. Preferably, the condenser operates in a mode where the refrigerant and reaction products do not contact; more preferably, it operates in a mode where the refrigerant and reaction products directly contact. The refrigerant is preferably an inert fluorocarbon solvent such as perfluoroolefins, hydrofluorocarbons, hydrofluoroethers, and perfluoropolyethers. Because the boiling points of carbamate, hexafluoroacetone, and trifluoromethyl fluoroformate differ significantly (at -84°C, -28°C, and -35°C, respectively), the reaction products are easily separated. Typically, the mixture of acyl fluoride and other products is separated and purified by a process of first crude separation followed by distillation. Specifically, the mixture of acyl fluoride and other products is first crudely separated at -75°C to obtain carbamate, and then crudely separated at -32°C to obtain trifluoromethyl fluoroformate. The crude acyl fluoride separated from the distillation process is further refined to obtain high-purity acyl fluoride products.
[0301] In some specific embodiments of this application, when the raw material is perfluorocyclobutene, the cracking product is mainly perfluoro-1,4-succinyl fluoride (boiling point 30°C). The product is condensed in a cryogenic condenser below 0°C, and the crude perfluoro-1,4-succinyl fluoride is stored in a cryogenic storage tank below 0°C. Further distillation can yield high-purity perfluoro-1,4-succinyl fluoride.
[0302] In some specific embodiments of this application, when the raw material is perfluoro-1-pentene, the cracking products are mainly heptafluorobutyryl fluoride and carbonyl fluoride. The products are condensed in an ultra-low temperature condenser below -100°C and stored in a cryogenic storage tank below -100°C. Preferably, the condenser operates in a mode where the refrigerant and reaction products do not contact; more preferably, it operates in a mode where the refrigerant and reaction products are in direct contact. The refrigerant is preferably an inert fluorocarbon solvent such as perfluoroolefins, hydrofluorocarbons, hydrofluoroethers, and perfluoropolyethers. Because the boiling points of heptafluorobutyryl fluoride and carbonyl fluoride differ significantly (7-9°C and -84°C, respectively), the reaction products are easily separated. Typically, the acyl fluoride mixture is separated and purified by a process of first crude separation followed by distillation. Specifically, the acyl fluoride mixture is first crudely separated at -75°C to obtain carbonyl fluoride. The crude product is then further distilled to obtain a high-purity acyl fluoride product.
[0303] In some specific embodiments of this application, when the raw material is perfluoro-2-pentene, the cracking products are mainly trifluoroacetyl fluoride, pentafluoropropionyl fluoride, and trifluoromethyl fluoroformate. The products are condensed in an ultra-low temperature condenser below -100°C and stored in a cryogenic storage tank below -100°C. Preferably, the condenser operates in a mode where the refrigerant and reaction products do not contact; more preferably, it operates in a mode where the refrigerant and reaction products are in direct contact. The refrigerant is preferably an inert fluorocarbon solvent such as perfluoroolefins, hydrofluorocarbons, hydrofluoroethers, and perfluoropolyethers. Because the boiling points of trifluoroacetyl fluoride, pentafluoropropionyl fluoride, and trifluoromethyl fluoroformate differ significantly (at -59°C, -26.5°C, and -35°C, respectively), the reaction products are easily separated. Typically, the acyl fluoride mixture is separated and purified by a process of first crude separation followed by distillation. Specifically, the acyl fluoride mixture is first crudely separated at -50°C to obtain trifluoroacetyl fluoride, and then crudely separated at -30°C to obtain trifluoromethyl fluoroformate. The crude product separated from the initial fraction is further purified by distillation to obtain high-purity acyl fluoride products.
[0304] In some specific embodiments of this application, when the raw material is perfluorocyclopentene, the cracking product is mainly perfluoro-1,5-glutaryl fluoride (boiling point 46-47℃). The product is retained in the reaction vessel, and at the end of the reaction, perfluoro-1,5-glutaryl fluoride is roughly separated. Further distillation yields high-purity perfluoro-1,5-glutaryl fluoride.
[0305] In some specific embodiments of this application, when the raw material is perfluoro-2-methyl-1-butene, the cracking products are mainly carbonyl fluoride and perfluorobutanone. The products are condensed in an ultra-low temperature condenser below -100°C and stored in a cryogenic storage tank below -100°C. Preferably, the condenser operates in a mode where the refrigerant and reaction products do not contact; more preferably, it operates in a mode where the refrigerant and reaction products are in direct contact. The refrigerant is preferably an inert fluorocarbon solvent such as perfluoroolefins, hydrofluorocarbons, hydrofluoroethers, and perfluoropolyethers. The product mixture is separated and purified by a process of first coarse fractionation followed by distillation.
[0306] In some specific embodiments of this application, when the raw material is perfluoro-3-methyl-1-butene, the cracking products are mainly carbonyl fluoride and perfluoro-2-methylpropionyl fluoride. The products are condensed in an ultra-low temperature condenser below -100°C and stored in a cryogenic storage tank below -100°C. Preferably, the condenser operates in a mode where the refrigerant and reaction products do not contact; more preferably, the refrigerant and reaction products are in direct contact. The refrigerant is preferably an inert fluorocarbon solvent such as perfluoroolefins, hydrofluorocarbons, hydrofluoroethers, and perfluoropolyethers. The product mixture is separated and purified by a process of first coarse separation followed by rectification distillation.
[0307] In some specific embodiments of this application, when the raw material is perfluoro-2-methyl-2-butene, the cracking products are mainly trifluoromethyl fluoroformate, trifluoroacetyl fluoride, and hexafluoroacetone. The products are condensed in an ultra-low temperature condenser below -100°C and stored in a cryogenic storage tank below -100°C. Preferably, the condenser operates in a mode where the refrigerant and reaction products do not contact; more preferably, it operates in a mode where the refrigerant and reaction products are in direct contact. The refrigerant is preferably an inert fluorocarbon solvent such as perfluoroolefins, hydrofluorocarbons, hydrofluoroethers, and perfluoropolyethers. The product mixture is separated and purified by a process of first coarse fractionation followed by distillation.
[0308] In some specific embodiments of this application, the raw material is perfluoro-4-methyl-2-pentene, and the cracking products are mainly trifluoromethyl fluoroformate, heptafluoroisobutyryl fluoride, and trifluoroacetyl fluoride. The products are condensed in an ultra-low temperature condenser below -100°C and stored in a cryogenic storage tank below -100°C. Preferably, the condenser operates in a mode where the refrigerant and reaction products do not contact; more preferably, the refrigerant and reaction products are in direct contact. The refrigerant is preferably an inert fluorocarbon solvent such as perfluoroolefins, hydrofluorocarbons, hydrofluoroethers, and perfluoropolyethers. Because the boiling points of trifluoromethyl fluoroformate, heptafluoroisobutyryl fluoride, and trifluoroacetyl fluoride differ significantly (at -35°C, -4~-2°C, and -59°C, respectively), the reaction products are easily separated. Typically, the acyl fluoride mixture is separated and purified by a combination of crude fractionation and distillation. Specifically, the acyl fluoride mixture is first crudely separated at -50°C to obtain trifluoroacetyl fluoride, and then crudely separated at -30°C to obtain trifluoromethyl fluoroformate. The crude acyl fluoride separated from the distillation process is further refined to obtain high-purity acyl fluoride products.
[0309] In some specific embodiments of this application, when the raw material is perfluoro-2-methyl-2-pentene, the cracking products are mainly hexafluoroacetone, pentafluoropropionyl fluoride, trifluoromethyl fluoroformate, and trifluoroacetyl fluoride. Since the boiling points of pentafluoropropionyl fluoride and hexafluoroacetone are very close (-26.5℃ and -28℃ respectively), they are difficult to separate by distillation. In this application, the mixture of pentafluoropropionyl fluoride, hexafluoroacetone, trifluoromethyl fluoroformate, and trifluoroacetyl fluoride obtained from the reaction is passed into a storage tank containing a selective absorbent. The selective absorbent absorbs the hexafluoroacetone, thus facilitating the separation of pentafluoropropionyl fluoride and hexafluoroacetone. Further, the selective absorbent is hydrogen fluoride, alcohol, or water. Hexafluoroacetone can form a complex with anhydrous hydrogen fluoride. After adding hydrogen fluoride to selectively absorb hexafluoroacetone, pentafluoropropionyl fluoride, trifluoromethyl fluoroformate, etc., can be distilled off, thereby achieving separation. The complex of hydrogen fluoride and hexafluoroacetone can be further separated to obtain hexafluoroacetone. Hexafluoroacetone reacts with alcohols to form unstable ketals and / or hemiketals, while pentafluoropropionyl fluoride and trifluoromethyl fluoroformate react with alcohols to form esters, which can then be separated by distillation. The alcohols can be anhydrous methanol, anhydrous ethanol, anhydrous isopropanol, etc., preferably methanol. Hexafluoroacetone can also form a monohydrate complex with water, while pentafluoropropionyl fluoride reacts with water to form pentafluoropropionic acid, trifluoroacetyl fluoride reacts with water to form trifluoroacetic acid, and trifluoromethyl fluoroformate reacts with water to form hydrogen fluoride, which can then be separated by distillation. To obtain pentafluoropropionyl fluoride, trifluoromethyl fluoroformate, etc., this application uses anhydrous hydrogen fluoride as a selective absorbent to separate pentafluoropropionyl fluoride from hexafluoroacetone and trifluoromethyl fluoroformate, etc. The remaining acyl fluoride mixture (trifluoroacetyl fluoride, trifluoromethyl fluoroformate, and pentafluoropropionyl fluoride) after selective absorption is condensed in an ultra-low temperature condenser below -100°C, and the acyl fluoride mixture is stored in a cryogenic storage tank below -100°C. Preferably, the condenser employs a mode where the refrigerant and reaction products do not come into contact; more preferably, it employs a mode where the refrigerant and reaction products directly contact. The refrigerant is preferably an inert fluorocarbon solvent such as perfluoroolefins, hydrofluorocarbons, hydrofluoroethers, and perfluoropolyethers. Because the boiling points of trifluoroacetyl fluoride, trifluoromethyl fluoroformate, and pentafluoropropionyl fluoride differ significantly (at -59℃, -35℃, and -26.5℃, respectively), the reaction products are easily separated. Typically, the acyl fluoride mixture is separated and purified by a process of first crude separation followed by distillation. Specifically, the acyl fluoride mixture is first crudely separated at -50℃ to obtain trifluoroacyl fluoride, and then crudely separated at -30℃ to obtain trifluoromethyl fluoroformate. The crude product is further purified by distillation to obtain a high-purity acyl fluoride product.
[0310] In some specific embodiments of this application, when the raw material is perfluoro-1,5-hexadiene (CF2=CFCF2CF2CF=CF2), the cracking products are mainly carbonyl fluoride and perfluoro-1,4-succinyl fluoride. The carbonyl fluoride product is condensed in an ultra-low temperature condenser below -100°C and stored in a cryogenic storage tank below -100°C. Preferably, the condenser adopts a mode in which the refrigerant and the reaction products do not come into contact; more preferably, the refrigerant and the reaction products come into direct contact. The refrigerant is preferably an inert fluorocarbon solvent such as perfluoroolefins, hydrofluorocarbons, hydrofluoroethers, and perfluoropolyethers. Perfluoro-1,4-succinyl fluoride is stored in the reaction vessel, and when the reaction is stopped, it is crudely separated by distillation. The crude product is further purified by distillation to obtain a high-purity acyl fluoride product.
[0311] In some specific embodiments of this application, when the raw material is perfluoro-3-heptene (CF3CF2CF=CFCF2CF2CF3), the cracking products are mainly perfluoropropionyl fluoride and perfluoron-butyryl fluoride. The products are condensed in an ultra-low temperature condenser below -50°C and stored in a cryogenic storage tank below -50°C. Preferably, the condenser operates in a mode where the refrigerant and reaction products do not contact; more preferably, it operates in a mode where the refrigerant and reaction products are in direct contact. The refrigerant is preferably an inert fluorocarbon solvent such as perfluoroolefins, hydrofluorocarbons, hydrofluoroethers, and perfluoropolyethers. The product mixture is separated and purified by a process of first coarse fractionation followed by distillation.
[0312] In some specific embodiments of this application, when the raw material is perfluoro-2-methyl-2-hexene (CF3CF2CF2CF=C(CF3)CF3), the cracking products are mainly hexafluoroacetone and perfluorobutyryl fluoride. The products are condensed in an ultra-low temperature condenser below -50°C and stored in a cryogenic storage tank below -50°C. Preferably, the condenser adopts a mode in which the refrigerant and the reaction products do not come into contact; more preferably, the mode in which the refrigerant and the reaction products come into direct contact is adopted. The refrigerant is preferably an inert fluorocarbon solvent such as perfluoroolefins, hydrofluorocarbons, hydrofluoroethers, and perfluoropolyethers. The product mixture is separated and purified by a method of first crude fractionation and then rectification.
[0313] In some specific embodiments of this application, when the raw material is perfluoro-3,4-dimethyl-3-hexene (CF3CF2(CF3)C=C(CF3)CF2CF3), the cracking product is mainly perfluorobutanone. The product is condensed in an ultra-low temperature condenser below -50°C and stored in a cryogenic storage tank below -50°C. Preferably, the condenser operates in a mode where the refrigerant and reaction product do not contact; more preferably, it operates in a mode where the refrigerant and reaction product are in direct contact. The refrigerant is preferably an inert fluorocarbon solvent such as perfluoroolefins, hydrofluorocarbons, hydrofluoroethers, and perfluoropolyethers. The product is separated and purified by a process of first crude fractionation followed by distillation.
[0314] Compared with the prior art, this utility model provides an apparatus for preparing fluorine-containing intermediates by ozone cracking of perfluoroolefins, including: cracking equipment for ozone cracking reaction of perfluoroolefins with oxygen-ozone mixed gas; product selective absorption and / or low temperature condensation recovery equipment, separation equipment and purification equipment; and tail gas absorption, separation and purification equipment.
[0315] This application has achieved the following beneficial effects:
[0316] 1) This application improves gas-liquid reaction efficiency and ozone utilization by optimizing reactor combination, while also improving reaction selectivity and effectively suppressing side reactions, thereby reducing the generation of by-products;
[0317] 2) By selectively absorbing and / or condensing the reaction products at low temperatures and further absorbing the residual tail gas with low-temperature ethanol, not only are the emissions of hazardous substances reduced, but the yield of the products is also effectively improved, making the production process more environmentally friendly.
[0318] 3) The use of low-temperature pyrolysis process significantly reduces energy consumption compared to existing technologies. Attached Figure Description
[0319] Figure 1 This is a schematic diagram of a falling film pyrolysis device in this application;
[0320] Figure 2 This is a schematic diagram of a pyrolysis reactor as the pyrolysis equipment in this application;
[0321] Figure 3 This is a schematic diagram of a pyrolysis tower as the pyrolysis equipment in this application;
[0322] Figure 4 This is a schematic diagram of the pyrolysis equipment in this application, which is a falling film pyrolysis reactor-pyrolysis vessel;
[0323] Figure 5 This is a schematic diagram of the pyrolysis equipment in this application, which is a pyrolysis reactor-pyrolysis tower;
[0324] Figure 6 This is a schematic diagram of the pyrolysis equipment in this application, which consists of a falling film pyrolyzer, a pyrolysis vessel, and a pyrolysis tower. Detailed Implementation
[0325] To further illustrate this utility model, a detailed description is provided below with reference to embodiments. However, it should be understood that these descriptions are merely for further illustrating the features and advantages of this utility model, and not for limiting the scope of the utility model claims.
[0326] There are no special restrictions on the source of any raw materials used in this invention; they can be purchased from the market or prepared using conventional methods known to those skilled in the art.
[0327] Example 1A: Ozone Oxidation Crack of Hexafluoropropylene
[0328] The pyrolysis reaction is carried out in a falling film reactor (falling film reactor parameters: diameter 125mm, height 900mm, 43 falling film reaction tubes, tube diameter 10mm, height 600mm; the same applies below). The falling film reactor is connected to the raw material batching tank, and the liquid outlet at the bottom of the reactor is connected to a reaction liquid receiving tank. Before feeding, the reaction system is heated to 120℃ and evacuated for 2 hours to remove water. Then, nitrogen is introduced and the pressure is maintained until the temperature drops to 20℃.
[0329] Add 3000g of trifluoroacetic acid to the raw material mixing tank. Use an ozone generator to produce an ozone-oxygen mixture with a concentration of 12wt%.
[0330] Trifluoroacetic acid from the raw material mixing tank flows uniformly (trifluoroacetic acid flow rate 15 g / h, the same below) from the raw material mixing tank into the liquid phase distributor at the top of the falling film reactor via a metering valve. After being evenly distributed, it forms a uniform liquid film on the inner wall of the falling film reactor and flows downward. The falling film reactor is then heated to a higher temperature.
[0331] Ozone-oxygen mixture and hexafluoropropylene gas enter the falling film reactor through the gas phase inlet at the bottom, flowing upwards to contact and react with the liquid film. The gas flow rate is controlled using a mass flow meter; the inlet velocity for hexafluoropropylene is 53 SCCM, and the inlet velocity for the ozone-oxygen mixture is 150 SCCM. The gas-liquid contact time in the falling film reactor is controlled at 5 ± 1 minutes, the temperature at 40 ± 5℃, and the inlet pressure at 0.2 ± 0.05 MPa.
[0332] Analysis of reaction solution samples:
[0333] Peroxide content (iodometric method): 0~10%;
[0334] Analysis of the content of each component by sampling at the air outlet:
[0335] Hexafluoropropylene: 18%~22%
[0336] Trifluoroacetic acid: 3%~5%
[0337] Trifluoroacetyl fluoride: 13%~15%
[0338] Carbonyl fluoride: 14%~18%
[0339] Trifluoromethyl fluoroformate: 24%~28%
[0340] O2: 16%~20%
[0341] O3: 1%~2%
[0342] Raw material conversion rate:
[0343] Hexafluoropropylene conversion rate: 60%~70%;
[0344] Ozone conversion rate: 50%~60%;
[0345] The reaction product gas mixture flows out from the gas phase outlet at the top of the falling film reactor and enters a -70℃ condenser and a -65℃ collection tank, where most of the product gas is condensed. The remaining non-condensable product gas and excess oxygen are absorbed through a -35℃ ethanol absorbent circulation tank and a falling film absorption tower. The tail gas after absorption enters a tail gas absorption tower for further treatment.
[0346] The reaction was completed after 120 hours. During the process, trifluoroacetic acid could be added to the raw material mixing tank as needed to maintain a continuous and stable reaction. A total of 2550g of hexafluoropropylene and 1543g of ozone-oxygen mixture were introduced during the process.
[0347] The product collection tank collected a total of 1966 g of product, including 892 g of hexafluoropropylene, 817 g of trifluoromethyl fluoroformate, and 256 g of trifluoroacetyl fluoride. After crude separation and distillation, 776 g of 99% trifluoromethyl fluoroformate (95% yield) and 246 g of 99% trifluoroacetyl fluoride (96% yield) were obtained, respectively.
[0348] The ethanol absorption liquid circulation tank collected 2344 g of product, including 1484 g of ethyl fluoroformate, 471 g of ethyl trifluoroformate, and 389 g of hydrogen fluoride. After extraction in an extraction tower, drying in a drying tower, and rectification in a rectification tower, 1395 g of 95% ethyl fluoroformate (94% yield) and 457 g of 99% ethyl trifluoroformate (97% yield) were obtained, respectively.
[0349] Example 1B: Ozone Oxidation Crack of Hexafluoropropylene
[0350] The pyrolysis reaction is carried out in a pyrolysis reactor (5L, self-priming agitator, hereinafter the same), which is connected to the raw material batching tank. Before feeding, the reaction system is heated to 120°C and vacuumed to remove water for 2 hours. Then, nitrogen is introduced and the pressure is maintained until the temperature drops to 20°C.
[0351] 3000g of trifluoroacetic acid was added to both the raw material mixing tank and the pyrolysis reactor. An ozone-oxygen mixture with a concentration of 12wt% was then generated using an ozone generator.
[0352] Trifluoroacetic acid from the raw material mixing tank flows into the pyrolysis reactor at a uniform rate (5 g / hour) through a metering valve. The pyrolysis reactor is then started with stirring and heating.
[0353] Ozone-oxygen mixture and hexafluoropropylene gas enter the pyrolysis reactor through the gas phase inlet, where they contact and react with the liquid phase material. The gas flow rate is controlled using a mass flow meter; the inlet velocity for hexafluoropropylene is 53 SCCM, and the inlet velocity for the ozone-oxygen mixture is 150 SCCM. The gas-liquid contact time in the pyrolysis reactor is controlled at 10 ± 1 minutes, the temperature at 40 ± 5℃, and the inlet pressure at 0.2 ± 0.05 MPa.
[0354] Analysis of reaction solution samples:
[0355] Peroxide content (iodometric method): 0~6%;
[0356] Analysis of the content of each component by sampling at the air outlet:
[0357] Hexafluoropropylene: 9%~12%
[0358] Trifluoroacetic acid: 3%~4%
[0359] Trifluoroyl fluoride: 16%~18%
[0360] Carbonyl fluoride: 18%~20%
[0361] Trifluoromethyl fluoroformate: 30%~33%
[0362] O2: 14%~16%
[0363] O3: 0.8%~1.2%
[0364] Raw material conversion rate:
[0365] Hexafluoropropylene conversion rate: 80%~84%;
[0366] Ozone conversion rate: 75%~79%;
[0367] The reaction product mixed gas material flows out from the gas phase outlet at the top of the pyrolysis reactor and enters the -70℃ condenser and the -65℃ collection tank. Most of the product gas condenses down, and the remaining non-condensable product gas and excess oxygen are absorbed by the -35℃ ethanol absorption liquid circulation tank and the falling film absorption tower. The tail gas after absorption enters the tail gas absorption tower for treatment.
[0368] The reaction was terminated after 120 hours. During the process, trifluoroacetic acid could be added to the raw material mixing tank as needed to maintain a continuous and stable reaction. A total of 2550 g of hexafluoropropylene and 1543 g of ozone-oxygen mixture were introduced during the process.
[0369] The product collection tank collected a total of 1831 g of product, including 510 g of hexafluoropropylene, 1005 g of trifluoromethyl fluoroformate, and 316 g of trifluoroacetyl fluoride. After crude separation and distillation, 965 g of 99% trifluoromethyl fluoroformate (96% yield) and 300 g of 99% trifluoroacetyl fluoride (95% yield) were obtained, respectively.
[0370] The ethanol absorption liquid circulation tank collected 2885 g of product, including 1827 g of ethyl fluoroformate, 579 g of ethyl trifluoroformate, and 479 g of hydrogen fluoride. After extraction in an extraction tower, drying in a drying tower, and distillation in a distillation tower, 1754 g of 95% ethyl fluoroformate (96% yield) and 550 g of 99% ethyl trifluoroformate (95% yield) were obtained, respectively.
[0371] Example 1C: Ozone Oxidation Crack of Hexafluoropropylene
[0372] The reaction is carried out in a cracking tower (cracking tower parameters: diameter 50mm, height 600mm, packing material is a 5mm diameter triangular metal spiral, porosity 95%, packing layer height 500mm, the same below). The cracking tower is connected to the raw material mixing tank, and the liquid outlet at the bottom of the reaction tower is connected to a reaction liquid receiving tank. The tower is equipped with multiple layers of packing to provide sufficient mass and heat transfer surface area. Before feeding, the reaction system is heated to 120℃ and evacuated for 2 hours to remove water. Then, nitrogen is introduced and the pressure is maintained until the temperature drops to 20℃.
[0373] Add 3000g of trifluoroacetic acid to the raw material mixing tank. Use an ozone generator to produce an ozone-oxygen mixture with a concentration of 12wt%.
[0374] Trifluoroacetic acid is fed from the raw material mixing tank at a uniform rate (10 g / hour) through a metering valve into the liquid distributor at the top of the cracking tower. After being evenly distributed, it forms a uniform liquid film on the surface of the packing material in the cracking tower and flows downward. The cracking tower is then heated to a higher temperature.
[0375] Ozone-oxygen mixture and hexafluoropropylene gas enter the pyrolysis tower through the gas phase inlet at the bottom of the tower, flowing upwards and contacting and reacting with the downward-flowing liquid film. The gas flow rate is controlled using a mass flow meter; the inlet velocity for hexafluoropropylene is 53 SCCM, and the inlet velocity for the ozone-oxygen mixture is 150 SCCM. The gas-liquid contact time in the pyrolysis tower is controlled at 8 ± 1 minutes, the temperature at 40 ± 5℃, and the inlet pressure at 0.2 ± 0.05 MPa.
[0376] Analysis of reaction solution samples:
[0377] Peroxide content (iodometric method): 0~8%;
[0378] Analysis of the content of each component by sampling at the air outlet:
[0379] Hexafluoropropylene: 15%~17%
[0380] Trifluoroacetic acid: 3%~4%
[0381] Trifluoroyl fluoride: 14%~16%
[0382] Carbonyl fluoride: 16%~18%
[0383] Trifluoromethyl fluoroformate: 27%~29%
[0384] O2: 16%~18%
[0385] O3: 1.1%~1.4%
[0386] Raw material conversion rate:
[0387] Hexafluoropropylene conversion rate: 70%~75%;
[0388] Ozone conversion rate: 65%~70%;
[0389] The reaction product mixed gas material flows out from the gas phase outlet at the top of the cracking tower and enters the -65℃ collection tank and the -70℃ condenser. Most of the product gas condenses down, and the remaining non-condensable product gas and excess oxygen are absorbed by the -35℃ ethanol absorption liquid circulation tank and the falling film absorption tower. The tail gas after absorption enters the tail gas absorption tower for treatment.
[0390] The reaction was terminated after 120 hours. Trifluoroacetic acid could be added to the raw material mixing tank as needed to maintain a continuous and stable reaction. A total of 2550 g of hexafluoropropylene and 1543 g of ozone-oxygen mixture were introduced during the process.
[0391] The product collection tank collected a total of 1912g of product, including 740g of hexafluoropropylene, 892g of trifluoromethyl fluoroformate, and 280g of trifluoroacetyl fluoride. After crude separation and distillation, 838g of 99% trifluoromethyl fluoroformate (yield 94%) and 266g of 99% trifluoroacetyl fluoride (yield 95%) were obtained.
[0392] The ethanol absorption liquid circulation tank collected 2560 g of product, including 1621 g of ethyl fluoroformate, 514 g of ethyl trifluoroformate, and 425 g of hydrogen fluoride. After extraction in an extraction tower, drying in a drying tower, and distillation in a distillation tower, 1540 g of 95% ethyl fluoroformate (95% yield) and 478 g of 99% ethyl trifluoroformate (93% yield) were obtained.
[0393] Example 1D: Ozone Oxidation Crack of Hexafluoropropylene
[0394] The reaction takes place in a falling film reactor and a pyrolysis vessel, which are connected in series. The falling film reactor is connected to the feed batching tank. Before feeding, the reaction system is heated to 120°C and evacuated for 2 hours to remove water. Then, nitrogen is introduced and the pressure is maintained until the temperature drops to 20°C.
[0395] 3000g of trifluoroacetic acid was added to both the raw material mixing tank and the pyrolysis reactor. An ozone-oxygen mixture with a concentration of 12wt% was then generated using an ozone generator.
[0396] Trifluoroacetic acid from the feed tank flows uniformly (5 mL / h) through a metering valve into the liquid distributor at the top of the falling film reactor, where it is evenly distributed and forms a uniformly thick liquid film on the inner wall of the reactor. This film then flows downwards, and the falling film reactor is heated. Finally, the trifluoroacetic acid flows out from the liquid outlet at the bottom of the falling film reactor and into the pyrolysis reactor through the liquid feed pipe. The pyrolysis reactor is then stirred and heated.
[0397] The gas flow rate was controlled using a mass flow meter. The inlet velocity of hexafluoropropylene was 53 SCCM, and the inlet velocity of the ozone-oxygen mixture was 150 SCCM. The ozone-oxygen mixture and hexafluoropropylene gas entered the falling film reactor through the gas phase inlet at the bottom, flowing upwards to contact and react with the liquid film. The gas-liquid contact time in the falling film reactor was controlled at 5 ± 1 minutes, the temperature at 40 ± 5℃, and the inlet pressure at 0.2 ± 0.05 MPa. The gas phase mixture exited the falling film reactor through the gas phase outlet and entered the pyrolysis reactor through the gas phase feed pipe, continuing to react with the liquid phase material inside. The gas-liquid contact residence time in the pyrolysis reactor was controlled at 10 ± 1 minutes, and the temperature at 40 ± 5℃.
[0398] Analysis of reaction solution samples:
[0399] Peroxide content (iodometric method): 0~6%;
[0400] Analysis of the content of each component by sampling at the air outlet:
[0401] Hexafluoropropylene: 7%~9%
[0402] Trifluoroacetic acid: 3%~4%
[0403] Trifluoroyl fluoride: 17%~19%
[0404] Carbonyl fluoride: 20%~23%
[0405] Trifluoromethyl fluoroformate: 32%~35%
[0406] O2: 14%~16%
[0407] O3: 0.5%~1%
[0408] Raw material conversion rate:
[0409] Hexafluoropropylene conversion rate: 84%~86%;
[0410] Ozone conversion rate: 81%~83%;
[0411] The reaction product mixed gas material flows out from the gas phase outlet at the top of the pyrolysis reactor and enters the -70℃ condenser and the -65℃ collection tank. Most of the product gas is condensed in stages, and the remaining non-condensable product gas and excess oxygen are absorbed by the -35℃ ethanol absorption liquid circulation tank and the falling film absorption tower. The tail gas after absorption enters the tail gas absorption tower for treatment.
[0412] The reaction was completed after 120 hours. During the process, trifluoroacetic acid could be added to the raw material mixing tank as needed to maintain a continuous and stable reaction. A total of 2550g of hexafluoropropylene and 1543g of ozone-oxygen mixture were introduced during the process.
[0413] The product collection tank collected a total of 1786g of product, including 382g of hexafluoropropylene, 1068g of trifluoromethyl fluoroformate, and 335g of trifluoroacetyl fluoride. After crude separation and distillation, 1015g of 99% trifluoromethyl fluoroformate (96% yield) and 322g of 99% trifluoroacetyl fluoride (96% yield) were obtained, respectively.
[0414] The ethanol absorption liquid circulation tank collected 3065g of product, including 1941g of ethyl fluoroformate, 616g of ethyl trifluoroformate, and 509g of hydrogen fluoride. After extraction in an extraction tower, drying in a drying tower, and distillation in a distillation tower, 1863g of 95% ethyl fluoroformate (96% yield) and 585g of 99% ethyl trifluoroformate (95% yield) were obtained, respectively.
[0415] Example 1E: Ozone Oxidation Crack of Hexafluoropropylene
[0416] The reaction takes place in a pyrolysis reactor and a pyrolysis tower connected in series. The pyrolysis tower is equipped with multiple layers of packing material to provide sufficient surface area for mass and heat transfer. The pyrolysis reactor is connected to the feed batching tank. Before feeding, the reaction system is heated to 120°C, evacuated to remove water for 2 hours, and then nitrogen is introduced and the pressure is maintained until the temperature drops to 20°C.
[0417] 3000g of trifluoroacetic acid was added to both the raw material mixing tank and the pyrolysis reactor. An ozone-oxygen mixture with a concentration of 12wt% was then generated using an ozone generator.
[0418] Trifluoroacetic acid from the raw material mixing tank flows uniformly into the pyrolysis reactor via a metering valve. The pyrolysis reactor is then stirred and heated. The bottom needle valve and metering valve are opened, allowing the trifluoroacetic acid to flow uniformly into the liquid distributor at the top of the pyrolysis tower, where it is evenly distributed and forms a uniformly thick liquid film on the packing surface, flowing downwards. The pyrolysis tower is then heated.
[0419] The gas flow rate was controlled using a mass flow meter. The inlet velocity of hexafluoropropylene was 53 SCCM, and the inlet velocity of the ozone-oxygen mixture was 150 SCCM. The ozone-oxygen mixture and hexafluoropropylene gas entered the reactor from the gas phase inlet at the top of the pyrolysis reactor, contacting and reacting with the liquid. The gas-liquid contact time in the pyrolysis reactor was controlled at 10 ± 1 minutes, the temperature at 40 ± 5℃, and the inlet pressure at 0.2 ± 0.05 MPa. The reaction product mixture in the pyrolysis reactor flowed out from the top gas phase outlet and entered the pyrolysis tower from the bottom gas phase inlet, flowing upwards and contacting and reacting with the downward-flowing liquid film in the tower. The gas-liquid contact time in the pyrolysis tower was controlled at 8 ± 1 minutes, and the temperature at 40 ± 5℃.
[0420] Analysis of reaction solution samples:
[0421] Peroxide content (iodometric method): 0~5%;
[0422] Analysis of the content of each component by sampling at the air outlet:
[0423] Hexafluoropropylene: 5%~7%
[0424] Trifluoroacetic acid: 3%~4%
[0425] Trifluoroyl fluoride: 18%~20%
[0426] Carbonyl fluoride: 20%~22%
[0427] Trifluoromethyl fluoroformate: 34%~36%
[0428] O2: 13%~15%
[0429] O3: 0.3%~0.5%
[0430] Raw material conversion rate:
[0431] Hexafluoropropylene conversion rate: 88%~91%;
[0432] Ozone conversion rate: 89%~92%;
[0433] The reaction product mixture flows out from the gas phase outlet at the top of the cracking tower and enters the -70℃ condenser and the -65℃ collection tank. Most of the product gas condenses down, while the remaining non-condensable product gas and excess oxygen are absorbed by the -35℃ ethanol absorption liquid circulation tank and the falling film absorption tower. The tail gas after absorption enters the tail gas absorption tower for treatment.
[0434] The reaction was completed after 120 hours. During the process, trifluoroacetic acid could be added to the raw material mixing tank as needed to maintain a continuous and stable reaction. A total of 2550g of hexafluoropropylene and 1543g of ozone-oxygen mixture were introduced during the process.
[0435] The product collection tank collected a total of 1750g of product, including 281g of hexafluoropropylene, 1118g of trifluoromethyl fluoroformate, and 351g of trifluoroacetyl fluoride. After crude separation and distillation, 1084g of 99% trifluoromethyl fluoroformate (97% yield) and 333g of 99% trifluoroacetyl fluoride (95% yield) were obtained, respectively.
[0436] The ethanol absorption liquid circulation tank collected 3209g of product, including 2032g of ethyl fluoroformate, 644g of ethyl trifluoroformate, and 533g of hydrogen fluoride. After extraction in an extraction tower, drying in a drying tower, and rectification in a rectification tower, 1971g of 95% ethyl fluoroformate (97% yield) and 618g of 99% ethyl trifluoroformate (96% yield) were obtained.
[0437] Example 1F: Ozone Oxidation Crack of Hexafluoropropylene
[0438] The reaction takes place in a falling film reactor, a pyrolysis vessel, and a pyrolysis tower, all connected in series. The pyrolysis tower contains multiple layers of packing material to provide ample surface area for mass and heat transfer. The falling film reactor is connected to the feed batching tank. Before feeding, the reaction system is heated to 120°C, evacuated for 2 hours to remove water, and then pressurized to 20°C after purging with nitrogen.
[0439] 3000g of trifluoroacetic acid was added to both the raw material mixing tank and the pyrolysis reactor. An ozone-oxygen mixture with a concentration of 12wt% was then generated using an ozone generator.
[0440] Trifluoroacetic acid from the feed tank flows uniformly through a metering valve into the liquid phase distributor at the top of the falling film reactor, where it is evenly distributed and forms a uniformly thick liquid film on the inner wall of the reactor, flowing downwards. The falling film reactor is then heated. Trifluoroacetic acid flows out from the liquid phase outlet at the bottom of the falling film reactor and flows into the pyrolysis reactor through the liquid phase inlet. The reactor is stirred and heated. The needle valve and metering valve at the bottom of the pyrolysis reactor are opened, allowing the trifluoroacetic acid in the reactor to flow uniformly into the liquid phase distributor at the top of the pyrolysis tower, where it is evenly distributed and forms a uniformly thick liquid film, flowing downwards. The pyrolysis tower is then heated.
[0441] The gas flow rate is controlled using a mass flow meter. The inlet velocity of hexafluoropropylene is 53 SCCM, and the inlet velocity of the ozone-oxygen mixture is 150 SCCM. The ozone-oxygen mixture and hexafluoropropylene gas enter the falling film reactor through the gas phase inlet at the bottom and flow upwards, contacting and reacting with the liquid film. The gas-liquid contact time in the falling film reactor is controlled at 5 ± 1 minutes, the temperature at 40 ± 5℃, and the inlet pressure at 0.2 ± 0.05 MPa. The gas phase mixture in the falling film reactor exits through the gas phase outlet at the top of the reactor and enters the pyrolysis reactor through the inlet pipe to react with the liquid phase material. The gas-liquid contact time in the pyrolysis reactor is controlled at 10 ± 1 minutes, and the temperature at 40 ± 5℃. The reaction product gas exiting the pyrolysis reactor gas phase outlet enters the pyrolysis tower from the bottom, flows upwards, and contacts and reacts with the downward-flowing liquid film in the tower. The gas-liquid contact time in the pyrolysis tower is controlled at 8 ± 1 minutes, and the temperature at 40 ± 5℃.
[0442] Analysis of reaction solution samples:
[0443] Peroxide content (iodometric method): 0~4%;
[0444] Analysis of the content of each component by sampling at the air outlet:
[0445] Hexafluoropropylene: 1%~3%
[0446] Trifluoroacetic acid: 2%~3%
[0447] Trifluoroyl fluoride: 20%~22%
[0448] Carbonyl fluoride: 22%~24%
[0449] Trifluoromethyl fluoroformate: 37%~38%
[0450] O2: 11%~13%
[0451] O3: 0~0.3%
[0452] Raw material conversion rate:
[0453] Hexafluoropropylene conversion rate: 95%~98%;
[0454] Ozone conversion rate: 95%~99%;
[0455] The reaction product mixed gas material flows out from the gas phase outlet at the top of the cracking tower and enters the -70℃ condenser and the -65℃ collection tank. Most of the product gas condenses down, and the remaining non-condensable product gas and excess oxygen are absorbed by the -35℃ ethanol absorption liquid circulation tank and the falling film absorption tower. The tail gas after absorption enters the tail gas absorption tower for treatment.
[0456] The reaction was completed after 120 hours. Trifluoroacetic acid could be added to the raw material mixing tank as needed to maintain a continuous and stable reaction. A total of 2550g of hexafluoropropylene and 1543g of ozone-oxygen mixture were introduced during the process.
[0457] The product collection tank collected a total of 1687 g of product, including 102 g of hexafluoropropylene, 1206 g of trifluoromethyl fluoroformate, and 379 g of trifluoroacetyl fluoride. After crude separation and distillation, 1170 g of 99% trifluoromethyl fluoroformate (97% yield) and 364 g of 99% trifluoroacetyl fluoride (96% yield) were obtained, respectively.
[0458] The ethanol absorption liquid circulation tank collected 3462g of product, including 2192g of ethyl fluoroformate, 695g of ethyl trifluoroformate, and 575g of hydrogen fluoride. After extraction in an extraction tower, drying in a drying tower, and distillation in a distillation tower, 2104g of 95% ethyl fluoroformate (96% yield) and 660g of 99% ethyl trifluoroformate (95% yield) were obtained, respectively.
[0459] Example 2A: Ozone Oxidation Crack of Perfluoro-4-methyl-2-pentene
[0460] The pyrolysis reaction was carried out in a falling film reactor (with parameters the same as in Example 1A). The falling film reactor was connected to the raw material batching tank, and the liquid outlet at the bottom of the reactor was connected to a reaction liquid receiving tank. Before feeding, the reaction system was heated to 120°C and evacuated for 2 hours to remove water. Then, nitrogen was introduced and the pressure was maintained until the temperature dropped to 20°C.
[0461] Add 3000g of perfluoro-4-methyl-2-pentene and 500g of trifluoroacetic acid to the raw material mixing tank. Use an ozone generator to produce an ozone-oxygen mixture with an ozone concentration of 12wt%.
[0462] The perfluoro-4-methyl-2-pentene and trifluoroacetic acid solution in the raw material mixing tank flows uniformly (41.7 g / h) from the raw material mixing tank into the liquid phase distributor at the top of the falling film reactor (the parameters of the falling film reactor are the same as in Example 1A) through a metering valve. After uniform distribution, a liquid film of uniform thickness is formed on the inner wall of the falling film reactor and flows downward. The falling film reactor is then heated to a higher temperature.
[0463] Ozone-oxygen mixture enters the falling film reactor through the gas phase inlet at the bottom, flows upward, and reacts with the liquid film. The gas flow rate is controlled by a mass flow meter, with the ozone-oxygen mixture inlet velocity set at 200 SCCM. The gas-liquid contact time in the falling film reactor is controlled at 5 ± 1 minutes, the temperature at 40 ± 5℃, and the inlet pressure at 0.2 ± 0.05 MPa.
[0464] Analysis of reaction solution samples:
[0465] Peroxide content (iodometric method): 0~7%;
[0466] Composition of air outlet sampling analysis:
[0467] Perfluoro-4-methyl-2-pentene: 27%~28%
[0468] Trifluoroacetic acid: 2%~3%
[0469] Heptafluoroisobutyryl fluoride: 23%~25%
[0470] Trifluoroacetyl fluoride: 7%~9%
[0471] Trifluoromethyl fluoroformate: 14%~16%
[0472] O2: 22%~23%
[0473] O3: 1%~2%
[0474] Raw material conversion rate:
[0475] Perfluoro-4-methyl-2-pentene conversion: 60%~65%;
[0476] Ozone conversion rate: 50%~55%;
[0477] The reaction product gas mixture flows out from the gas phase outlet at the top of the falling film reactor and enters a -70℃ condenser and a -65℃ collection tank, where most of the product gas is condensed. The remaining non-condensable product gas and excess oxygen are absorbed through a -35℃ ethanol absorbent circulation tank and a falling film absorption tower. The tail gas after absorption enters a tail gas absorption tower for further treatment.
[0478] The reaction was completed after 84 hours. During the process, trifluoroacetic acid or perfluoro-4-methyl-2-pentene could be added to the raw material mixing tank as needed to maintain the continuous and stable reaction. A total of 1440g of ozone-oxygen mixture was introduced during the process.
[0479] The product collection tank collected a total of 2715.8g of product, including 933g of heptafluoroisobutyryl fluoride, 444g of trifluoromethyl fluoroformate, 139g of trifluoroacetyl fluoride, and 1200g of perfluoro-4-methyl-2-pentene. After crude separation and distillation, 924g of 99% heptafluoroisobutyryl fluoride (99% yield), 431g of 99% trifluoromethyl fluoroformate (97% yield), and 132g of 99% trifluoroacetyl fluoride (95% yield) were obtained.
[0480] The ethanol absorption liquid circulation tank collected 740g of product, including 116g of ethyl heptafluoroisobutyrate, 265g of ethyl fluoroformate, 256g of ethyl trifluoroacetate, and 116g of hydrogen fluoride. After extraction in an extraction tower, drying in a drying tower, and distillation in a distillation tower, 725g of 99% ethyl heptafluoroisobutyrate (98% yield), 254g of 95% ethyl fluoroformate (96% yield), and 243g of 99% ethyl trifluoroacetate (95% yield) were obtained.
[0481] Example 2B: Ozone Oxidative Crack of Perfluoro-4-methyl-2-pentene
[0482] The pyrolysis reaction is carried out in a pyrolysis reactor connected to the raw material batching tank. Before feeding, the reaction system is heated to 120°C and evacuated for 2 hours to remove water. Then, nitrogen is introduced and the pressure is maintained until the temperature drops to 20°C.
[0483] 3000g of perfluoro-4-methyl-2-pentene and 500g of trifluoroacetic acid were added to the raw material mixing tank, and 3000g of perfluoro-4-methyl-2-pentene and 500g of trifluoroacetic acid were added to the pyrolysis reactor. An ozone-oxygen mixture with an ozone concentration of 12wt% was generated using an ozone generator.
[0484] The perfluoro-4-methyl-2-pentene and trifluoroacetic acid solution in the raw material mixing tank flows into the pyrolysis reactor at a uniform rate (20.9 g / h) through a metering valve. The pyrolysis reactor is then started with stirring and heating.
[0485] Ozone-oxygen mixed gas enters the pyrolysis reactor through the gas phase inlet, where it contacts and reacts with the liquid phase material. The gas flow rate is controlled by a mass flow meter, with the ozone-oxygen mixed gas inlet velocity set at 200 SCCM. The gas-liquid contact time in the pyrolysis reactor is controlled at 10 ± 1 minutes, the temperature at 40 ± 5℃, and the inlet pressure at 0.2 ± 0.05 MPa.
[0486] Analysis of reaction solution samples:
[0487] Peroxide content (iodometric method): 0~5%;
[0488] Composition of air outlet sampling analysis:
[0489] Perfluoro-4-methyl-2-pentene: 12%~13%
[0490] Trifluoroacetic acid: 2%~3%
[0491] Heptafluoroisobutyryl fluoride: 32%~35%
[0492] Trifluoroacetyl fluoride: 10%~12%
[0493] Trifluoromethyl fluoroformate: 20%~22%
[0494] O2: 19%~21%
[0495] O3: 0.7%~1.1%
[0496] Raw material conversion rate:
[0497] Perfluoro-4-methyl-2-pentene conversion: 81%~83%;
[0498] Ozone conversion rate: 80%~83%;
[0499] The reaction product mixed gas material flows out from the gas phase outlet at the top of the pyrolysis reactor and enters the -70℃ condenser and the -65℃ collection tank. Most of the product gas condenses down, and the remaining non-condensable product gas and excess oxygen are absorbed by the -35℃ ethanol absorption liquid circulation tank and the falling film absorption tower. The tail gas after absorption enters the tail gas absorption tower for treatment.
[0500] The reaction was completed after 84 hours. During the process, trifluoroacetic acid or perfluoro-4-methyl-2-pentene could be added to the raw material mixing tank as needed to maintain the continuous and stable reaction. A total of 1440g of ozone-oxygen mixture was introduced during the process.
[0501] The product collection tank collected a total of 2612g of product, including 1275g of heptafluoroisobutyryl fluoride, 606g of trifluoromethyl fluoroformate, 190g of trifluoroacetyl fluoride, and 540g of perfluoro-4-methyl-2-pentene. After crude separation and distillation, 1250g of 99% heptafluoroisobutyryl fluoride (98% yield), 582g of 99% trifluoromethyl fluoroformate (96% yield), and 180g of 99% trifluoroacetyl fluoride (95% yield) were obtained.
[0502] The ethanol absorption liquid circulation tank collected 1011g of product, including 159g of ethyl heptafluoroisobutyrate, 362g of ethyl fluoroformate, 349g of ethyl trifluoroacetate, and 141g of hydrogen fluoride. After extraction in an extraction tower, drying in a drying tower, and distillation in a distillation tower, 157g of 99% ethyl heptafluoroisobutyrate (99% yield), 344g of 95% ethyl fluoroformate (95% yield), and 335g of 99% ethyl trifluoroacetate (96% yield) were obtained.
[0503] Example 2C: Ozone Oxidative Crack of Perfluoro-4-methyl-2-pentene
[0504] The reaction takes place in a cracking tower connected to a feed tank. The tower is filled with multiple layers of packing material to provide sufficient surface area for mass and heat transfer. The liquid outlet at the bottom of the cracking tower is connected to a reaction liquid receiving tank. Before feeding, the reaction system is heated to 120°C and evacuated for 2 hours to remove water. Then, nitrogen is introduced and the pressure is maintained until the temperature drops to 20°C.
[0505] Add 3000g of perfluoro-4-methyl-2-pentene and 500g of trifluoroacetic acid to the raw material mixing tank. Use an ozone generator to produce an ozone-oxygen mixture with an ozone concentration of 12wt%.
[0506] A solution of perfluoro-4-methyl-2-pentene and trifluoroacetic acid is fed uniformly (41.7 g / h) from the raw material mixing tank through a metering valve into the liquid distributor at the top of the cracking tower. After uniform distribution, a liquid film of uniform thickness is formed on the surface of the packing material in the cracking tower and flows downward. The cracking tower is then heated to a higher temperature.
[0507] Ozone-oxygen mixed gas enters the pyrolysis tower through the gas phase inlet at the bottom of the tower, flows upward, and contacts and reacts with the downward-flowing liquid film. The gas flow rate is controlled by a mass flow meter, with the ozone-oxygen mixed gas inlet velocity set at 200 SCCM. The gas-liquid contact time in the pyrolysis tower is controlled at 8 ± 1 minutes, the temperature at 40 ± 5℃, and the inlet pressure at 0.2 ± 0.05 MPa.
[0508] Analysis of reaction solution samples:
[0509] Peroxide content (iodometric method): 0~6%;
[0510] Composition of air outlet sampling analysis:
[0511] Perfluoro-4-methyl-2-pentene: 19%~21%
[0512] Trifluoroacetic acid: 2%~3%
[0513] Heptafluoroisobutyryl fluoride: 28%~30%
[0514] Trifluoroacetyl fluoride: 9%~11%
[0515] Trifluoromethyl fluoroformate: 16%~19%
[0516] O2: 21%~22%
[0517] O3: 1.1%~1.3%
[0518] Raw material conversion rate:
[0519] Perfluoro-4-methyl-2-pentene conversion: 71%~73%;
[0520] Ozone conversion rate: 70%~74%;
[0521] The reaction product mixed gas material flows out from the gas phase outlet at the top of the cracking tower and enters the -70℃ condenser and the -65℃ collection tank. Most of the product gas condenses down, and the remaining non-condensable product gas and excess oxygen are absorbed by the -35℃ ethanol absorption liquid circulation tank and the falling film absorption tower. The tail gas after absorption enters the tail gas absorption tower for treatment.
[0522] The reaction was terminated after 84 hours. During the process, trifluoroacetic acid or perfluoro-4-methyl-2-pentene could be added to the raw material mixing tank as needed to maintain a continuous and stable reaction. A total of 1440g of ozone-oxygen mixture was introduced.
[0523] The product collection tank collected a total of 2659g of product, including 1120g of heptafluoroisobutyryl fluoride, 532g of trifluoromethyl fluoroformate, 167g of trifluoroacetyl fluoride, and 840g of perfluoro-4-methyl-2-pentene. After crude separation and distillation, 1075g of 99% heptafluoroisobutyryl fluoride (96% yield), 516g of 99% trifluoromethyl fluoroformate (97% yield), and 157g of 99% trifluoroacetyl fluoride (94% yield) were obtained.
[0524] The ethanol absorption liquid circulation tank collected 888g of product, including 139g of ethyl heptafluoroisobutyrate, 318g of ethyl fluoroformate, 307g of ethyl trifluoroacetate, and 124g of hydrogen fluoride. After extraction in an extraction tower, drying in a drying tower, and distillation in a distillation tower, the following results were obtained: 136g of 99% ethyl heptafluoroisobutyrate (98% yield); 305g of 95% ethyl fluoroformate (96% yield); and 292g of 99% ethyl trifluoroacetate (95% yield).
[0525] Example 2D: Ozone Oxidative Crack of Perfluoro-4-methyl-2-pentene
[0526] The reaction takes place in a falling film reactor and a pyrolysis vessel, which are connected in series. The falling film reactor is connected to the feed batching tank. Before feeding, the reaction system is heated to 120°C and evacuated for 2 hours to remove water. Then, nitrogen is introduced and the pressure is maintained until the temperature drops to 20°C.
[0527] 3000g of perfluoro-4-methyl-2-pentene and 500g of trifluoroacetic acid were added to the raw material mixing tank, and 3000g of perfluoro-4-methyl-2-pentene and 500g of trifluoroacetic acid were added to the pyrolysis reactor. An ozone-oxygen mixture with an ozone concentration of 12wt% was generated using an ozone generator.
[0528] The perfluoro-4-methyl-2-pentene and trifluoroacetic acid solution in the raw material mixing tank flows uniformly into the liquid phase distributor at the top of the falling film reactor through a metering valve, where it is evenly distributed and forms a liquid film of uniform thickness on the inner wall of the reactor. This film then flows downwards, and the falling film reactor is heated. Finally, the perfluoro-4-methyl-2-pentene and trifluoroacetic acid solution flows out from the liquid phase outlet at the bottom of the falling film reactor and flows into the pyrolysis reactor through the liquid phase feed pipe. The pyrolysis reactor is then stirred and heated.
[0529] The gas flow rate is controlled using a mass flow meter, with the ozone-oxygen mixture entering at a velocity of 200 SCCM. The ozone-oxygen mixture enters the reactor from the gas phase inlet at the bottom of the falling film reactor, flows upward, contacts the liquid film, and reacts.
[0530] The gas-liquid contact time in the falling film reactor is controlled at 5±1 minutes, the temperature at 40±5℃, and the inlet pressure at 0.2±0.05MPa. The gas-phase mixture flows out from the gas-phase outlet at the top of the falling film reactor and enters the pyrolysis reactor through the gas-phase feed pipe, continuing to react with the liquid-phase material inside the reactor. The gas-liquid contact residence time in the pyrolysis reactor is controlled at 10±1 minutes, and the temperature at 40±5℃.
[0531] Liquid sampling and analysis:
[0532] Peroxide content (iodometric method): 0~5%;
[0533] Composition of air outlet sampling analysis:
[0534] Perfluoro-4-methyl-2-pentene: 8%~10%
[0535] Trifluoroacetic acid: 2%~3%
[0536] Heptafluoroisobutyryl fluoride: 36%~37%
[0537] Trifluoroacetyl fluoride: 11%~13%
[0538] Trifluoromethyl fluoroformate: 20%~23%
[0539] O2: 18%~21%
[0540] O3: 0.5%~0.8%
[0541] Raw material conversion rate:
[0542] Perfluoro-4-methyl-2-pentene conversion: 86%~88%;
[0543] Ozone conversion rate: 84%~87%;
[0544] The reaction product mixed gas material flows out from the gas phase outlet at the top of the pyrolysis reactor and enters the -70℃ condenser and the -65℃ collection tank. Most of the product gas is condensed in stages, and the remaining non-condensable product gas and excess oxygen are absorbed by the -35℃ ethanol absorption liquid circulation tank and the falling film absorption tower. The tail gas after absorption enters the tail gas absorption tower for treatment.
[0545] The reaction ended after 84 hours. During the process, trifluoroacetic acid or perfluoro-4-methyl-2-pentene could be added to the raw material tank as needed to maintain the continuous and stable reaction. A total of 1440g of ozone-oxygen mixture was introduced during the process.
[0546] The product collection tank collected a total of 2588g of product, including 1353g of heptafluoroisobutyryl fluoride, 643g of trifluoromethyl fluoroformate, 202g of trifluoroacetyl fluoride, and 390g of perfluoro-4-methyl-2-pentene. After crude separation and distillation, 1312g of 99% heptafluoroisobutyryl fluoride (97% yield), 617g of 99% trifluoromethyl fluoroformate (96% yield), and 192g of 99% trifluoroacetyl fluoride (95% yield) were obtained.
[0547] The ethanol absorption liquid circulation tank collected 1073g of product, including 168g of ethyl heptafluoroisobutyrate, 384g of ethyl fluoroformate, 371g of ethyl trifluoroacetate, and 150g of hydrogen fluoride. After extraction in an extraction tower, drying in a drying tower, and distillation in a distillation tower, 165g of 99% ethyl heptafluoroisobutyrate (98% yield), 361g of 95% ethyl fluoroformate (94% yield), and 356g of 99% ethyl trifluoroacetate (96% yield) were obtained.
[0548] Example 2E: Ozone Oxidative Crack of Perfluoro-4-methyl-2-pentene
[0549] The reaction takes place in a pyrolysis reactor and a pyrolysis tower connected in series. The pyrolysis tower is equipped with multiple layers of packing material to provide sufficient surface area for mass and heat transfer. The pyrolysis reactor is connected to the feed batching tank. Before feeding, the reaction system is heated to 120°C, evacuated to remove water for 2 hours, and then nitrogen is introduced and the pressure is maintained until the temperature drops to 20°C.
[0550] 3000g of perfluoro-4-methyl-2-pentene and 500g of trifluoroacetic acid were added to the raw material mixing tank, and 3000g of perfluoro-4-methyl-2-pentene and 500g of trifluoroacetic acid were added to the pyrolysis reactor. An ozone-oxygen mixture with an ozone concentration of 12wt% was generated using an ozone generator.
[0551] The perfluoro-4-methyl-2-pentene and trifluoroacetic acid solution in the feed tank flows uniformly into the pyrolysis reactor through a metering valve. The pyrolysis reactor is stirred and heated. The bottom needle valve and metering valve are opened, allowing the trifluoroacetic acid in the reactor to flow uniformly into the liquid distributor at the top of the pyrolysis tower, where it is evenly distributed and forms a uniformly thick liquid film on the packing surface, flowing downwards. The pyrolysis tower is then heated.
[0552] The gas flow rate is controlled using a mass flow meter, with the ozone-oxygen mixture inlet velocity set at 200 SCCM. The ozone-oxygen mixture enters the reactor from the gas phase inlet at the top of the pyrolysis reactor, contacting and reacting with the liquid. The gas-liquid contact time in the pyrolysis reactor is controlled at 10 ± 1 minutes, the temperature at 40 ± 5℃, and the inlet pressure at 0.2 ± 0.05 MPa. The reaction product mixture exits from the gas phase outlet at the top of the pyrolysis reactor and enters the pyrolysis tower from the gas phase inlet at the bottom, flowing upwards to contact and react with the downward-flowing liquid film. The gas-liquid contact time in the pyrolysis tower is controlled at 8 ± 1 minutes, and the temperature at 40 ± 5℃.
[0553] Analysis of reaction solution samples:
[0554] Peroxide content (iodometric method): 0~5%;
[0555] Composition of air outlet sampling analysis:
[0556] Perfluoro-4-methyl-2-pentene: 5%~7%
[0557] Trifluoroacetic acid: 2%~3%
[0558] Heptafluoroisobutyryl fluoride: 36%~38%
[0559] Trifluoroacetyl fluoride: 11%~13%
[0560] Trifluoromethyl fluoroformate: 22%~23%
[0561] O2: 19%~20%
[0562] O3: 0.3%~0.5%
[0563] Raw material conversion rate:
[0564] Perfluoro-4-methyl-2-pentene conversion: 91%~93%;
[0565] Ozone conversion rate: 90%~94%;
[0566] The reaction product mixture flows out from the gas phase outlet at the top of the cracking tower and enters the -70℃ condenser and the -65℃ collection tank. Most of the product gas is condensed in stages, while the remaining non-condensable product gas and excess oxygen are absorbed by the -35℃ ethanol absorption liquid circulation tank and the falling film absorption tower. The tail gas after absorption enters the tail gas absorption tower for treatment.
[0567] The reaction was completed after 84 hours. During the process, trifluoroacetic acid or perfluoro-4-methyl-2-pentene could be added to the raw material mixing tank as needed to maintain the continuous and stable reaction. A total of 1440g of ozone-oxygen mixture was introduced during the process.
[0568] The product collection tank collected a total of 2569g of product, including 1415g of heptafluoroisobutyryl fluoride, 673g of trifluoromethyl fluoroformate, 211g of trifluoroacetyl fluoride, and 270g of perfluoro-4-methyl-2-pentene. After crude separation and distillation, 1387g of 99% heptafluoroisobutyryl fluoride (98% yield), 639g of 99% trifluoromethyl fluoroformate (95% yield), and 203g of 99% trifluoroacetyl fluoride (96% yield) were obtained.
[0569] The ethanol absorption liquid circulation tank collected 1122g of product, including 176g of ethyl heptafluoroisobutyrate, 402g of ethyl fluoroformate, 388g of ethyl trifluoroacetate, and 157g of hydrogen fluoride. After extraction in an extraction tower, drying in a drying tower, and rectification in a rectification tower, 173g of 99% ethyl heptafluoroisobutyrate (98% yield), 382g of 95% ethyl fluoroformate (95% yield), and 372g of 99% ethyl trifluoroacetate (96% yield) were obtained.
[0570] Example 2F: Ozone Oxidative Crack of Perfluoro-4-methyl-2-pentene
[0571] The reaction takes place in a falling film reactor, a pyrolysis vessel, and a pyrolysis tower, all connected in series. The pyrolysis tower contains multiple layers of packing material to provide ample surface area for mass and heat transfer. The falling film reactor is connected to the feed batching tank. Before feeding, the reaction system is heated to 120°C, evacuated for 2 hours to remove water, and then pressurized to 20°C after purging with nitrogen.
[0572] 3000g of perfluoro-4-methyl-2-pentene and 500g of trifluoroacetic acid were added to the raw material mixing tank, and 3000g of perfluoro-4-methyl-2-pentene and 500g of trifluoroacetic acid were added to the pyrolysis reactor. An ozone-oxygen mixture with an ozone concentration of 12wt% was generated using an ozone generator.
[0573] The perfluoro-4-methyl-2-pentene and trifluoroacetic acid solution in the feed tank flows uniformly through a metering valve into the liquid phase distributor at the top of the falling film reactor, where it is evenly distributed and forms a liquid film of uniform thickness on the inner wall of the reactor, flowing downwards. The falling film reactor is then heated. The perfluoro-4-methyl-2-pentene and trifluoroacetic acid solution flows out from the liquid phase outlet at the bottom of the falling film reactor and flows into the pyrolysis reactor through the liquid phase inlet. The reactor is stirred and heated. The needle valve and metering valve at the bottom of the pyrolysis reactor are opened, and the perfluoro-4-methyl-2-pentene and trifluoroacetic acid solution in the reactor flows uniformly into the liquid phase distributor at the top of the pyrolysis tower, where it is evenly distributed and forms a liquid film of uniform thickness, flowing downwards. The pyrolysis tower is then heated.
[0574] The gas flow rate is controlled using a mass flow meter, with the ozone-oxygen mixture inlet velocity set at 200 SCCM. The ozone-oxygen mixture enters the falling film reactor through the gas phase inlet at the bottom and flows upwards, contacting and reacting with the liquid film. The gas-liquid contact time in the falling film reactor is controlled at 5 ± 1 minutes, the temperature at 40 ± 5℃, and the inlet pressure at 0.2 ± 0.05 MPa. The gas phase mixture in the falling film reactor exits through the gas phase outlet at the top of the reactor and enters the pyrolysis reactor through the inlet pipe to react with the liquid phase material. The gas-liquid contact time in the pyrolysis reactor is controlled at 10 ± 1 minutes, and the temperature at 40 ± 5℃. The reaction product gas exiting the pyrolysis reactor enters the pyrolysis tower from the bottom, flows upwards, and reacts with the downward-flowing liquid film. The gas-liquid contact time in the pyrolysis tower is controlled at 8 ± 1 minutes, and the temperature at 40 ± 5℃.
[0575] Analysis of reaction solution samples:
[0576] Peroxide content (iodometric method): 0~4%;
[0577] Composition of air outlet sampling analysis:
[0578] Perfluoro-4-methyl-2-pentene: 1%~3%
[0579] Trifluoroacetic acid: 1%~2%
[0580] Heptafluoroisobutyryl fluoride: 39%~43%
[0581] Trifluoroacetyl fluoride: 13%~15%
[0582] Trifluoromethyl fluoroformate: 24%~27%
[0583] O2: 18%~19%
[0584] O3: 0~0.2%
[0585] Raw material conversion rate:
[0586] Perfluoro-4-methyl-2-pentene conversion: 96%~99%;
[0587] Ozone conversion rate: 97%~100%;
[0588] The reaction product mixed gas material flows out from the gas phase outlet at the top of the cracking tower and enters the -70℃ condenser and the -65℃ collection tank. Most of the product gas is condensed in stages, and the remaining non-condensable product gas and excess oxygen are absorbed by the -35℃ ethanol absorption liquid circulation tank and the falling film absorption tower. The tail gas after absorption enters the tail gas absorption tower for treatment.
[0589] The reaction was completed after 84 hours. During the process, trifluoroacetic acid or perfluoro-4-methyl-2-pentene could be added to the raw material mixing tank as needed to maintain the continuous and stable reaction. A total of 1440g of ozone-oxygen mixture was introduced during the process.
[0590] The product collection tank collected a total of 2541g of product, including 1509g of heptafluoroisobutyryl fluoride, 717g of trifluoromethyl fluoroformate, 225g of trifluoroacetyl fluoride, and 90g of perfluoro-4-methyl-2-pentene. After crude separation and distillation, 1464g of 99% heptafluoroisobutyryl fluoride (97% yield), 688g of 99% trifluoromethyl fluoroformate (96% yield), and 216g of 99% trifluoroacetyl fluoride (96% yield) were obtained.
[0591] The ethanol absorption liquid circulation tank collected 1196g of product, including 188g of ethyl heptafluoroisobutyrate, 428g of ethyl fluoroformate, 413g of ethyl trifluoroacetate, and 167g of hydrogen fluoride. After extraction in an extraction tower, drying in a drying tower, and distillation in a distillation tower, 184g of 99% ethyl heptafluoroisobutyrate (98% yield), 407g of 95% ethyl fluoroformate (95% yield), and 392g of 99% ethyl trifluoroacetate (95% yield) were obtained.
[0592] Example 3A: Ozone Oxidative Crack of Perfluoro-2-methyl-2-pentene
[0593] The pyrolysis reaction is carried out in a falling film reactor, which is connected to a feed tank. The liquid outlet at the bottom of the reactor is connected to a reaction liquid receiving tank. Before feeding, the reaction system is heated to 120°C and evacuated for 2 hours to remove water. Then, nitrogen is introduced and the pressure is maintained until the temperature drops to 20°C.
[0594] Add 3000g of perfluoro-2-methyl-2-pentene and 2000g of trifluoroacetic acid to the raw material mixing tank. Use an ozone generator to produce an ozone-oxygen mixture with an ozone concentration of 12wt%.
[0595] The perfluoro-2-methyl-2-pentene and trifluoroacetic acid solution in the raw material mixing tank flows uniformly (29.8 g / hour) from the raw material mixing tank into the liquid phase distributor at the top of the falling film reactor (the parameters of the falling film reactor are the same as in Example 1A) through a metering valve. After uniform distribution, a liquid film of uniform thickness is formed on the inner wall of the falling film reactor and flows downward. The falling film reactor is then heated to a higher temperature.
[0596] Ozone-oxygen mixture enters the falling film reactor through the gas phase inlet at the bottom, flows upward, and reacts with the liquid film. The gas flow rate is controlled by a mass flow meter, with the ozone-oxygen mixture inlet velocity set at 200 SCCM. The gas-liquid contact time in the falling film reactor is controlled at 5 ± 1 minutes, the temperature at 40 ± 5℃, and the inlet pressure at 0.2 ± 0.05 MPa.
[0597] Analysis of reaction solution samples:
[0598] Peroxide content (iodometric method): 0~10%;
[0599] Composition of air outlet sampling analysis:
[0600] Perfluoro-2-methyl-2-pentene: 20%~24%
[0601] Trifluoroacetic acid: 4%~5%
[0602] Hexafluoroacetone: 13%~16%
[0603] Pentafluoropropionyl fluoride: 2%~4%
[0604] Trifluoromethyl fluoroformate: 7%~10%
[0605] Trifluoroyl fluoride: 7%~9%
[0606] O2: 37%~40%
[0607] O3: 2%~3%
[0608] Raw material conversion rate:
[0609] Perfluoro-2-methyl-2-pentene conversion: 55%~60%;
[0610] Ozone conversion rate: 45%~55%;
[0611] The reaction product mixed gas flows out from the gas phase outlet at the top of the falling film reactor, first entering a 0℃ hexafluoroacetone collection tank to absorb hexafluoroacetone (the collection tank contains anhydrous hydrogen fluoride as a selective absorbent), and then entering a -70℃ condenser and a -65℃ collection tank, where most of the product gas is condensed. Finally, the remaining non-condensable product gas and excess oxygen are absorbed through a -35℃ ethanol absorption liquid circulation tank and a falling film absorption tower. The tail gas after absorption enters the tail gas absorption tower for treatment.
[0612] The reaction was terminated after 168 hours. During the process, perfluoro-2-methyl-2-pentene or trifluoroacetic acid could be added to the raw material mixing tank as needed to maintain the continuous and stable reaction. A total of 2880g of ozone-oxygen mixture was introduced during the process.
[0613] The hexafluoroacetone absorption tank collected a total of 840g of hexafluoroacetone and 1350g of perfluoro-2-methyl-2-pentene. After decomposition and distillation, 823g of 99% hexafluoroacetone was obtained, with a yield of 98%.
[0614] The product collection tank collected a total of 641 g of product, including 131.5 g of pentafluoropropionyl fluoride, 305 g of trifluoromethyl fluoroformate, and 204 g of trifluoroacetyl fluoride. After crude separation and distillation, 127 g of 98% pentafluoropropionyl fluoride (97% yield), 293 g of 98% trifluoromethyl fluoroformate (96% yield), and 194 g of 99% trifluoroacetyl fluoride (95% yield) were obtained.
[0615] The ethanol absorption liquid circulation tank collected 691 g of product, including 182 g of ethyl fluoroformate, 375 g of ethyl trifluoroacetate, 38 g of ethyl pentafluoropropionate, and 96 g of hydrogen fluoride. After extraction in an extraction tower, drying in a drying tower, and distillation in a distillation tower, 173 g of 95% ethyl fluoroformate (95% yield), 364 g of 99% ethyl trifluoroacetate (97% yield), and 37 g of 99% ethyl pentafluoropropionate (98% yield) were obtained.
[0616] Example 3B: Ozone Oxidative Crack of Perfluoro-2-methyl-2-pentene
[0617] The pyrolysis reaction is carried out in a pyrolysis reactor (5L, self-priming agitator), which is connected to the raw material batching tank. Before feeding, the reaction system is heated to 120°C and evacuated for 2 hours to remove water. Then, nitrogen is introduced and the pressure is maintained until the temperature drops to 20°C.
[0618] 3000g of perfluoro-2-methyl-2-pentene and 2000g of trifluoroacetic acid were added to the raw material mixing tank, and 3000g of perfluoro-2-methyl-2-pentene and 2000g of trifluoroacetic acid were added to the pyrolysis reactor. An ozone-oxygen mixture with an ozone concentration of 12wt% was generated using an ozone generator.
[0619] The perfluoro-2-methyl-2-pentene and trifluoroacetic acid solution in the raw material mixing tank flows into the pyrolysis reactor at a uniform rate (30 g / hour) through a metering valve. The pyrolysis reactor is then started with stirring and heating.
[0620] Ozone-oxygen mixed gas enters the pyrolysis reactor through the gas phase inlet, where it contacts and reacts with the liquid phase material. The gas flow rate is controlled by a mass flow meter, with the ozone-oxygen mixed gas inlet velocity set at 200 SCCM. The gas-liquid contact time in the pyrolysis reactor is controlled at 10 ± 1 minutes, the temperature at 40 ± 5℃, and the inlet pressure at 0.2 ± 0.05 MPa.
[0621] Analysis of reaction solution samples:
[0622] Peroxide content (iodometric method): 0~7%;
[0623] Composition of air outlet sampling analysis:
[0624] Perfluoro-2-methyl-2-pentene: 11%~14%
[0625] Trifluoroacetic acid: 4%~5%
[0626] Hexafluoroacetone: 19%~22%
[0627] Pentafluoropropionyl fluoride: 3%~5%
[0628] Trifluoromethyl fluoroformate: 9%~13%
[0629] Trifluoroyl fluoride: 10%~12%
[0630] O2: 35%~37%
[0631] O3: 1%~2%
[0632] Raw material conversion rate:
[0633] Perfluoro-2-methyl-2-pentene conversion: 75%~77%;
[0634] Ozone conversion rate: 71%~74%;
[0635] The reaction product gas mixture flows out from the gas phase outlet at the top of the reactor, first entering a 0℃ hexafluoroacetone collection tank to absorb hexafluoroacetone (the collection tank contains anhydrous hydrogen fluoride as a selective absorbent), and then entering a -70℃ condenser and a -65℃ collection tank, where most of the product gas is condensed. Finally, the remaining non-condensable product gas and excess oxygen are absorbed through a -35℃ ethanol absorption liquid circulation tank and a falling film absorption tower. The tail gas after absorption enters the tail gas absorption tower for treatment.
[0636] The reaction was terminated after 168 hours. During the process, perfluoro-2-methyl-2-pentene or trifluoroacetic acid could be added to the raw material mixing tank as needed to maintain the continuous and stable reaction. A total of 2880g of ozone-oxygen mixture was introduced during the process.
[0637] A total of 1161g of hexafluoroacetone and 720g of perfluoro-2-methyl-2-pentene were collected in the hexafluoroacetone absorption tank. After decomposition and distillation, 1126g of 99% hexafluoroacetone was obtained, with a yield of 97%.
[0638] The product collection tank collected a total of 885 g of product, including 182 g of pentafluoropropionyl fluoride, 421 g of trifluoromethyl fluoroformate, and 282 g of trifluoroacetyl fluoride. After crude separation and distillation, 178 g of 98% pentafluoropropionyl fluoride (97% yield), 404 g of 98% trifluoromethyl fluoroformate (96% yield), and 268 g of 99% trifluoroacetyl fluoride (95% yield) were obtained.
[0639] The ethanol absorption liquid circulation tank collected 955g of product, including 252g of ethyl fluoroformate, 518g of ethyl trifluoroacetate, 53g of ethyl pentafluoropropionate, and 133g of hydrogen fluoride. After extraction in an extraction tower, drying in a drying tower, and distillation in a distillation tower, 237g of 95% ethyl fluoroformate (94% yield), 497g of 99% ethyl trifluoroacetate (96% yield), and 52g of 99% ethyl pentafluoropropionate (98% yield) were obtained.
[0640] Example 3C: Ozone Oxidative Crack of Perfluoro-2-methyl-2-pentene
[0641] The reaction takes place in a cracking tower, with the liquid outlet at the bottom of the tower connected to a reaction liquid receiving tank. Before feeding, the reaction system is heated to 120°C and evacuated for 2 hours to remove water. Then, nitrogen is introduced and the pressure is maintained until the temperature drops to 20°C.
[0642] Add 3000g of perfluoro-2-methyl-2-pentene and 2000g of trifluoroacetic acid to the raw material mixing tank. Use an ozone generator to produce an ozone-oxygen mixture with an ozone concentration of 12wt%.
[0643] A solution of perfluoro-2-methyl-2-pentene and trifluoroacetic acid is fed uniformly (30 g / hour) from the raw material mixing tank through a metering valve into the liquid distributor at the top of the cracking tower. After being evenly distributed, the liquid forms a uniformly thick liquid film on the surface of the packing material in the cracking tower and flows downward. The cracking tower is then heated to a higher temperature.
[0644] Ozone-oxygen mixed gas enters the pyrolysis tower through the gas phase inlet at the bottom of the tower, flows upward, and contacts and reacts with the downward-flowing liquid film. The gas flow rate is controlled by a mass flow meter, with the ozone-oxygen mixed gas inlet velocity set at 200 SCCM. During the controlled process, the gas-liquid contact time in the pyrolysis tower is 8 ± 1 minutes, the temperature is 40 ± 5℃, and the inlet pressure is 0.2 ± 0.05 MPa.
[0645] Analysis of reaction solution samples:
[0646] Peroxide content (iodometric method): 0~7%;
[0647] Composition of air outlet sampling analysis:
[0648] Perfluoro-2-methyl-2-pentene: 15%~18%
[0649] Trifluoroacetic acid: 4%~5%
[0650] Hexafluoroacetone: 16%~18%
[0651] Pentafluoropropionyl fluoride: 3%~5%
[0652] Trifluoromethyl fluoroformate: 8%~10%
[0653] Trifluoroyl fluoride: 10%~12%
[0654] O2: 35%~38%
[0655] O3: 1.5%~2.4%
[0656] Raw material conversion rate:
[0657] Perfluoro-2-methyl-2-pentene conversion: 66%~70%;
[0658] Ozone conversion rate: 62%~65%;
[0659] The reaction product mixed gas flows out from the gas phase outlet at the top of the cracking tower, first entering the 0℃ hexafluoroacetone collection tank to absorb hexafluoroacetone (the collection tank is filled with the selective absorbent anhydrous hydrogen fluoride), and then entering the -70℃ condenser and the -65℃ collection tank, where most of the product gas is condensed. Finally, the remaining non-condensable product gas and excess oxygen are absorbed by the -35℃ ethanol absorption liquid circulation tank and the falling film absorption tower. The tail gas after absorption enters the tail gas absorption tower for treatment.
[0660] The reaction was terminated after 168 hours. During the process, perfluoro-2-methyl-2-pentene or trifluoroacetic acid could be added to the raw material mixing tank as needed to maintain the continuous and stable reaction. A total of 2880g of ozone-oxygen mixture was introduced during the process.
[0661] A total of 1039g of hexafluoroacetone and 960g of perfluoro-2-methyl-2-pentene were collected in the hexafluoroacetone absorption tank. After decomposition and distillation, 1018g of 99% hexafluoroacetone was obtained, with a yield of 98%.
[0662] The product collection tank collected a total of 792 g of product, including 163 g of pentafluoropropionyl fluoride, 377 g of trifluoromethyl fluoroformate, and 252 g of trifluoroacetyl fluoride. After crude separation and distillation, 160 g of 98% pentafluoropropionyl fluoride (97% yield), 362 g of 98% trifluoromethyl fluoroformate (96% yield), and 239 g of 99% trifluoroacetyl fluoride (95% yield) were obtained.
[0663] The ethanol absorption liquid circulation tank collected 855g of product, including 225g of ethyl fluoroformate, 464g of ethyl trifluoroformate, 47g of ethyl pentafluoropropionate, and 119g of hydrogen fluoride. After extraction in an extraction tower, drying in a drying tower, and rectification in a rectification tower, 216g of 95% ethyl fluoroformate (96% yield), 445g of 99% ethyl trifluoroformate (96% yield), and 46g of 99% ethyl pentafluoropropionate (98% yield) were obtained.
[0664] Example 3D: Ozone Oxidative Crack of Perfluoro-2-methyl-2-pentene
[0665] The reaction takes place in a falling film reactor and a pyrolysis vessel, which are connected in series. The falling film reactor is connected to the feed batching tank. Before feeding, the reaction system is heated to 120°C and evacuated for 2 hours to remove water. Then, nitrogen is introduced and the pressure is maintained until the temperature drops to 20°C.
[0666] 3000g of perfluoro-2-methyl-2-pentene and 2000g of trifluoroacetic acid were added to the raw material mixing tank, and 3000g of perfluoro-4-methyl-2-pentene and 2000g of trifluoroacetic acid were added to the pyrolysis reactor. An ozone-oxygen mixture with an ozone concentration of 12wt% was generated using an ozone generator.
[0667] The perfluoro-2-methyl-2-pentene and trifluoroacetic acid solution in the raw material mixing tank flows uniformly into the liquid phase distributor at the top of the falling film reactor through a metering valve, where it is evenly distributed and forms a liquid film of uniform thickness on the inner wall of the reactor. This film then flows downwards, and the falling film reactor is heated. Finally, the perfluoro-2-methyl-2-pentene and trifluoroacetic acid solution flows out from the liquid phase outlet at the bottom of the falling film reactor and flows into the pyrolysis reactor through the liquid phase feed pipe. The pyrolysis reactor is then stirred and heated.
[0668] The gas flow rate is controlled using a mass flow meter, with the ozone-oxygen mixture entering at a velocity of 200 SCCM. The ozone-oxygen mixture enters the reactor from the gas phase inlet at the bottom of the falling film reactor, flows upward, contacts the liquid film, and reacts.
[0669] The gas-liquid contact time in the falling film reactor is controlled at 5±1 minutes, the temperature at 40±5℃, and the inlet pressure at 0.2±0.05MPa. The gas-phase mixture flows out from the gas-phase outlet at the top of the falling film reactor and enters the pyrolysis reactor through the gas-phase feed pipe, continuing to react with the liquid-phase material inside the reactor. The gas-liquid contact residence time in the pyrolysis reactor is controlled at 10±1 minutes, and the temperature at 40±5℃.
[0670] Reaction solution sampling and analysis
[0671] Peroxide content (iodometric method): 0~6%;
[0672] Composition of air outlet sampling analysis:
[0673] Perfluoro-2-methyl-2-pentene: 8%-10%
[0674] Trifluoroacetic acid: 4%~5%
[0675] Hexafluoroacetone: 20%~23%
[0676] Pentafluoropropionyl fluoride: 3%~5%
[0677] Trifluoromethyl fluoroformate: 10%~12%
[0678] Trifluoroyl fluoride: 11%~14%
[0679] O2: 35%~37%
[0680] O3: 0.8%~1.2%
[0681] Raw material conversion rate:
[0682] Perfluoro-2-methyl-2-pentene conversion: 81%~83%;
[0683] Ozone conversion rate: 82%~83%;
[0684] The reaction product gas mixture flows out from the gas phase outlet at the top of the reactor and first enters the 0℃ hexafluoroacetone collection tank to absorb hexafluoroacetone (the collection tank is filled with the selective absorbent anhydrous hydrogen fluoride). Then it enters the -70℃ condenser and the -65℃ collection tank, where most of the product gas is condensed. Finally, the remaining non-condensable product gas and excess oxygen are absorbed by the -35℃ ethanol absorption liquid circulation tank and the falling film absorption tower. The tail gas after absorption enters the tail gas absorption tower for treatment.
[0685] The reaction was terminated after 168 hours. During the process, perfluoro-2-methyl-2-pentene or trifluoroacetic acid could be added to the raw material mixing tank as needed to maintain the continuous and stable reaction. A total of 2880g of ozone-oxygen mixture was introduced during the process.
[0686] A total of 1252g of hexafluoroacetone and 540g of perfluoro-2-methyl-2-pentene were collected in the hexafluoroacetone absorption tank. After decomposition and distillation, 1227g of 99% hexafluoroacetone was obtained, with a yield of 98%.
[0687] The product collection tank collected a total of 955g of product, including 196g of pentafluoropropionyl fluoride, 455g of trifluoromethyl fluoroformate, and 304g of trifluoroacetyl fluoride. After crude separation and distillation, 192g of 98% pentafluoropropionyl fluoride (96% yield), 432g of 98% trifluoromethyl fluoroformate (95% yield), and 292g of 99% trifluoroacetyl fluoride (96% yield) were obtained, respectively.
[0688] The ethanol absorption liquid circulation tank collected 1031g of product, including 272g of ethyl fluoroformate, 559g of ethyl trifluoroformate, 57g of ethyl pentafluoropropionate, and 144g of hydrogen fluoride. After extraction in an extraction tower, drying in a drying tower, and distillation in a distillation tower, 258g of 95% ethyl fluoroformate (95% yield), 531g of 99% ethyl trifluoroformate (95% yield), and 56g of 99% ethyl pentafluoropropionate (98% yield) were obtained.
[0689] Example 3E: Ozone Oxidative Crack of Perfluoro-2-methyl-2-pentene
[0690] The reaction takes place in a cracking reactor and a cracking tower, which are connected in series. The cracking reactor is connected to the raw material batching tank, and the liquid outlet at the bottom of the cracking tower is connected to a reaction liquid receiving tank. Before feeding, the reaction system is heated to 120°C and evacuated for 2 hours to remove water. Then, nitrogen gas is introduced and the pressure is maintained until the temperature drops to 20°C.
[0691] 3000g of perfluoro-2-methyl-2-pentene and 2000g of trifluoroacetic acid were added to the raw material mixing tank, and 3000g of perfluoro-2-methyl-2-pentene and 2000g of trifluoroacetic acid were added to the pyrolysis reactor. An ozone-oxygen mixture with an ozone concentration of 12wt% was generated using an ozone generator.
[0692] The perfluoro-2-methyl-2-pentene and trifluoroacetic acid solution in the raw material mixing tank flows uniformly into the pyrolysis reactor through a metering valve. The pyrolysis reactor is stirred and heated. The bottom needle valve and metering valve are opened, and the trifluoroacetic acid in the reactor flows uniformly into the liquid distributor at the top of the pyrolysis tower, where it is evenly distributed, forming a uniformly thick liquid film on the surface of the packing material in the pyrolysis tower, which then flows downwards. The pyrolysis tower is then heated.
[0693] The gas flow rate is controlled using a mass flow meter, with the ozone-oxygen mixture inlet velocity set at 200 SCCM. The ozone-oxygen mixture enters the reactor from the gas phase inlet at the top of the pyrolysis reactor, contacting and reacting with the liquid. The gas-liquid contact time in the pyrolysis reactor is controlled at 10 ± 1 minutes, the temperature at 40 ± 5℃, and the inlet pressure at 0.2 ± 0.05 MPa. The reaction product mixture exits from the gas phase outlet at the top of the pyrolysis reactor and enters the pyrolysis tower from the gas phase inlet at the bottom, flowing upwards to contact and react with the downward-flowing liquid film. The gas-liquid contact time in the pyrolysis tower is controlled at 8 ± 1 minutes, and the temperature at 40 ± 5℃.
[0694] Analysis of reaction solution samples:
[0695] Peroxide content (iodometric method): 0~5%;
[0696] Composition of air outlet sampling analysis:
[0697] Perfluoro-2-methyl-2-pentene: 6%~8%
[0698] Trifluoroacetic acid: 4%~5%
[0699] Hexafluoroacetone: 21%~23%
[0700] Pentafluoropropionyl fluoride: 3%~5%
[0701] Trifluoromethyl fluoroformate: 11%~13%
[0702] Trifluoroyl fluoride: 13%~16%
[0703] O2: 35%~38%
[0704] O3: 0.5%~1%
[0705] Raw material conversion rate:
[0706] Perfluoro-2-methyl-2-pentene conversion: 85%~88%;
[0707] Ozone conversion rate: 85%~90%;
[0708] The reaction product mixed gas flows out from the gas phase outlet at the top of the cracking tower, first entering the 0℃ hexafluoroacetone collection tank to absorb hexafluoroacetone (the collection tank is filled with the selective absorbent anhydrous hydrogen fluoride), and then entering the -70℃ condenser and the -65℃ collection tank, where most of the product gas is condensed. Finally, the remaining non-condensable product gas and excess oxygen are absorbed by the -35℃ ethanol absorption liquid circulation tank and the falling film absorption tower. The tail gas after absorption enters the tail gas absorption tower for treatment.
[0709] The reaction was terminated after 168 hours. During the process, perfluoro-2-methyl-2-pentene or trifluoroacetic acid could be added to the raw material mixing tank as needed to maintain the continuous and stable reaction. A total of 2880g of ozone-oxygen mixture was introduced during the process.
[0710] A total of 1313g of hexafluoroacetone and 420g of perfluoro-2-methyl-2-pentene were collected in the hexafluoroacetone absorption tank. After decomposition and distillation, 1274g of 99% hexafluoroacetone was obtained, with a yield of 97%.
[0711] The product collection tank collected a total of 1002g of product, including 206g of pentafluoropropionyl fluoride, 477g of trifluoromethyl fluoroformate, and 319g of trifluoroacetyl fluoride. After crude separation and distillation, 200g of 98% pentafluoropropionyl fluoride (97% yield), 458g of 98% trifluoromethyl fluoroformate (96% yield), and 303g of 99% trifluoroacetyl fluoride (95% yield) were obtained.
[0712] The ethanol absorption liquid circulation tank collected 1081g of product, including 285g of ethyl fluoroformate, 586g of ethyl trifluoroformate, 59g of ethyl pentafluoropropionate, and 151g of hydrogen fluoride. After extraction in an extraction tower, drying in a drying tower, and distillation in a distillation tower, 271g of 95% ethyl fluoroformate (95% yield), 562g of 99% ethyl trifluoroformate (96% yield), and 56g of 99% ethyl pentafluoropropionate (95% yield) were obtained.
[0713] Example 3F: Ozone Oxidative Crack of Perfluoro-2-methyl-2-pentene
[0714] The reaction takes place in a falling film reactor, a pyrolysis vessel, and a pyrolysis tower, all connected in series. The falling film reactor is connected to the feed tank. Before feeding, the reaction system is heated to 120°C and evacuated for 2 hours to remove water. Then, nitrogen is introduced and the pressure is maintained until the temperature drops to 20°C.
[0715] 3000g of perfluoro-2-methyl-2-pentene and 2000g of trifluoroacetic acid were added to the raw material mixing tank, and 3000g of perfluoro-4-methyl-2-pentene and 2000g of trifluoroacetic acid were added to the pyrolysis reactor. An ozone-oxygen mixture with an ozone concentration of 12wt% was generated using an ozone generator.
[0716] The perfluoro-2-methyl-2-pentene and trifluoroacetic acid solution in the feed tank flows uniformly through a metering valve into the liquid phase distributor at the top of the falling film reactor, where it is evenly distributed and forms a liquid film of uniform thickness on the inner wall of the reactor, flowing downwards. The falling film reactor is then heated. The perfluoro-2-methyl-2-pentene and trifluoroacetic acid solution flows out from the liquid phase outlet at the bottom of the falling film reactor and flows into the pyrolysis reactor through the liquid phase inlet. The reactor is stirred and heated. The needle valve and metering valve at the bottom of the pyrolysis reactor are opened, and the perfluoro-2-methyl-2-pentene and trifluoroacetic acid solution in the reactor flows uniformly into the liquid phase distributor at the top of the pyrolysis tower, where it is evenly distributed and forms a liquid film of uniform thickness, flowing downwards. The pyrolysis tower is then heated.
[0717] The gas flow rate is controlled using a mass flow meter, with the ozone-oxygen mixture inlet velocity set at 200 SCCM. The ozone-oxygen mixture enters the falling film reactor through the gas phase inlet at the bottom and flows upwards, contacting and reacting with the liquid film. The gas-liquid contact time in the falling film reactor is controlled at 5 ± 1 minutes, the temperature at 40 ± 5℃, and the inlet pressure at 0.2 ± 0.05 MPa. The gas phase mixture in the falling film reactor exits through the gas phase outlet at the top of the reactor and enters the pyrolysis reactor through the inlet pipe to react with the liquid phase material. The gas-liquid contact time in the pyrolysis reactor is controlled at 10 ± 1 minutes, and the temperature at 40 ± 5℃. The reaction product gas exiting the pyrolysis reactor enters the pyrolysis tower from the bottom, flows upwards, and reacts with the downward-flowing liquid film. The gas-liquid contact time in the pyrolysis tower is controlled at 8 ± 1 minutes, and the temperature at 40 ± 5℃.
[0718] Liquid sampling and analysis:
[0719] Peroxide content (iodometric method): 0~5%;
[0720] Composition of air outlet sampling analysis:
[0721] Perfluoro-2-methyl-2-pentene: 2.5%~3.5%
[0722] Trifluoroacetic acid: 4%~5%
[0723] Hexafluoroacetone: 24%~26%
[0724] Pentafluoropropionyl fluoride: 4%~6%
[0725] Trifluoromethyl fluoroformate: 12%~13%
[0726] Trifluoroyl fluoride: 14%~16%
[0727] O2: 35%~37%
[0728] O3: 0~0.5%
[0729] Raw material conversion rate:
[0730] Perfluoro-2-methyl-2-pentene conversion: 94%~97%;
[0731] Ozone conversion rate: 95%~99%;
[0732] The reaction product mixed gas flows out from the gas phase outlet at the top of the cracking tower, first entering the 0℃ hexafluoroacetone collection tank to absorb hexafluoroacetone (the collection tank is filled with the selective absorbent anhydrous hydrogen fluoride), and then entering the -70℃ condenser and the -65℃ collection tank, where most of the product gas is condensed. Finally, the remaining non-condensable product gas and excess oxygen are absorbed by the -35℃ ethanol absorption liquid circulation tank and the falling film absorption tower. The tail gas after absorption enters the tail gas absorption tower for treatment.
[0733] The reaction was terminated after 168 hours. During the process, perfluoro-2-methyl-2-pentene or trifluoroacetic acid could be added to the raw material mixing tank as needed to maintain the continuous and stable reaction. A total of 2880g of ozone-oxygen mixture was introduced during the process.
[0734] A total of 1436g of hexafluoroacetone and 180g of perfluoro-2-methyl-2-pentene were collected in the hexafluoroacetone absorption tank. After decomposition and distillation, 1407g of 99% hexafluoroacetone was obtained, with a yield of 98%.
[0735] The product collection tank collected a total of 1095g of product, including 225g of pentafluoropropionyl fluoride, 521g of trifluoromethyl fluoroformate, and 349g of trifluoroacetyl fluoride. After crude separation and distillation, 216g of 98% pentafluoropropionyl fluoride (96% yield), 500g of 98% trifluoromethyl fluoroformate (96% yield), and 331g of 99% trifluoroacetyl fluoride (95% yield) were obtained.
[0736] The ethanol absorption liquid circulation tank collected 1182g of product, including 311g of ethyl fluoroformate, 641g of ethyl trifluoroformate, 65g of ethyl pentafluoropropionate, and 165g of hydrogen fluoride. After extraction in an extraction tower, drying in a drying tower, and distillation in a distillation tower, 292g of 95% ethyl fluoroformate (94% yield), 615g of 99% ethyl trifluoroformate (96% yield), and 61g of 99% ethyl pentafluoropropionate (94% yield) were obtained.
[0737] The above description of the embodiments is only for the purpose of helping to understand the method and core idea of this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made to this utility model without departing from the principle of this utility model, and these improvements and modifications also fall within the protection scope of the claims of this utility model.
Claims
1. An apparatus for preparing fluorine-containing intermediates by ozone cracking of perfluoroolefins, characterized in that, include: Cracking equipment for ozonochemical cracking of perfluoroolefins with an oxygen-ozone mixture; Product selective absorption and / or cryogenic condensation recovery equipment, separation equipment, and purification equipment; Equipment for exhaust gas absorption, separation and purification.
2. The apparatus for preparing fluorine-containing intermediates by ozone cracking of perfluoroolefins according to claim 1, characterized in that, The pyrolysis equipment includes: The equipment includes a raw material mixing tank, an ozone generator, and a pyrolysis reaction device; the pyrolysis reaction device includes one or more of the following connected in series: a falling film reactor, a pyrolysis vessel, and a pyrolysis tower.
3. The apparatus for preparing fluorine-containing intermediates by ozone cracking of perfluoroolefins according to claim 2, characterized in that, The pyrolysis reaction equipment includes a falling film reactor, a pyrolysis vessel, or a pyrolysis tower; The falling film reactor has an air inlet at its lower end for oxygen-ozone mixed gas and raw material gas to enter the reactor; a liquid outlet at its lower end for discharging the reaction liquid; a liquid inlet at its top for liquid reaction raw materials to enter; and a gas outlet at its top for gaseous products to escape during the reaction. The top of the pyrolysis vessel is provided with a gas inlet and a liquid inlet for the gaseous and liquid reactants to enter, respectively; the top of the pyrolysis vessel is provided with a gas outlet for the gaseous products to escape during the reaction; and the bottom of the pyrolysis vessel is provided with a liquid outlet for the reaction liquid to be discharged. The top of the pyrolysis tower is provided with a liquid inlet for the liquid reaction raw materials to enter; the top of the pyrolysis tower is provided with a gas outlet for the gaseous products to escape during the reaction; the bottom of the pyrolysis tower is provided with a gas inlet for the oxygen-ozone mixture and the reaction raw material gas to enter the pyrolysis tower; the bottom of the pyrolysis tower is also provided with a liquid outlet for the discharge of the reaction liquid.
4. The apparatus for preparing fluorine-containing intermediates by ozone cracking of perfluoroolefins according to claim 2, characterized in that, The pyrolysis reaction equipment includes a falling film reactor and a pyrolysis vessel; The falling film reactor and the pyrolysis vessel are connected in series, wherein the falling film reactor is connected to the raw material batching tank; the liquid outlet at the bottom of the falling film reactor is connected to the liquid inlet at the top of the pyrolysis vessel, and the gas outlet at the top of the falling film reactor is connected to the gas inlet at the top of the pyrolysis vessel. The top of the pyrolysis vessel is provided with a gas outlet for the gaseous products to escape during the reaction; the bottom of the pyrolysis vessel is provided with a liquid outlet for discharging the reaction liquid.
5. The apparatus for preparing fluorine-containing intermediates by ozone cracking of perfluoroolefins according to claim 2, characterized in that, The pyrolysis reaction equipment includes a pyrolysis reactor and a pyrolysis tower; The pyrolysis reactor and the pyrolysis tower are connected in series, wherein the pyrolysis reactor is connected to the raw material batching tank; the liquid outlet at the bottom of the pyrolysis reactor is connected to the liquid inlet at the top of the pyrolysis tower. The gas outlet at the top of the pyrolysis reactor is connected to the gas inlet at the bottom of the pyrolysis tower; The pyrolysis tower is equipped with a liquid outlet at the bottom.
6. The apparatus for preparing fluorine-containing intermediates by ozone cracking of perfluoroolefins according to claim 2, characterized in that, The pyrolysis reaction equipment includes a falling film reactor, a pyrolysis vessel, and a pyrolysis tower; The falling film reactor, pyrolysis vessel, and pyrolysis tower are connected in series, wherein the falling film reactor is connected to the raw material batching tank; The lower end of the falling film reactor is provided with an air inlet for the oxygen-ozone mixed gas and the reaction raw material gas to enter. The falling film reactor is equipped with a liquid inlet at the top for the liquid reaction raw materials to enter; The lower end of the falling film reactor is provided with a liquid outlet, which is connected to the liquid inlet at the top of the pyrolysis vessel. The falling film reactor is provided with a gas outlet at the top, which is connected to the gas inlet at the top of the pyrolysis vessel. The bottom of the pyrolysis vessel is provided with a liquid outlet, which is connected to the liquid inlet at the top of the pyrolysis tower; The top of the pyrolysis vessel is provided with a gas outlet, which is connected to the gas inlet at the bottom of the pyrolysis tower. The top of the pyrolysis tower is provided with a gas outlet for the gaseous products to escape during the reaction process. The pyrolysis tower is equipped with a liquid outlet at the bottom for discharging the reaction liquid.
7. The apparatus for preparing fluorine-containing intermediates by ozone cracking of perfluoroolefins according to any one of claims 2 to 4 or claim 6, characterized in that, The falling film reactor is equipped with a liquid phase distributor at the top, which is connected to the outlet of the raw material batching tank via a metering valve, so that the liquid phase reaction raw materials are evenly distributed and form a downward flowing liquid film on the inner wall of the falling film reactor.
8. The apparatus for preparing fluorine-containing intermediates by ozone cracking of perfluoroolefins according to claim 1, characterized in that, The product selective absorption and / or cryogenic condensation recovery equipment, separation equipment, and purification equipment include: Acyl fluoride absorption system, cryogenic condensation system, acyl fluoride storage tank, acyl fluoride crude fractionation tower and distillation tower.
9. The apparatus for preparing fluorine-containing intermediates by ozone cracking of perfluoroolefins according to claim 1, characterized in that, The exhaust gas absorption, separation, and purification equipment includes: The system includes a tail gas absorption system, a mixed ester extraction tower, a drying tower, a mixed ester crude fractionation tower, and a distillation tower.
10. The apparatus for preparing fluorine-containing intermediates by ozone cracking of perfluoroolefins according to claim 1, characterized in that, The product selective absorption device is equipped with a selective absorbent or a non-selective absorbent. The exhaust gas absorption device is equipped with a selective absorbent and / or a non-selective absorbent. The selective absorbent is selected from anhydrous hydrogen fluoride; The non-selective absorbent is selected from C1-C5 aliphatic alcohols.