A photo-oxidation and hydrolysis integrated reaction device and application thereof

Abstract

This invention provides an integrated photo-oxidation and hydrolysis reaction apparatus and its application, relating to the field of photo-oxidation technology. The integrated photo-oxidation and hydrolysis reaction apparatus includes a reaction tower, a light source system, and a spray circulation system. The light source system includes several LED light sources, which are staggered and parallel to each other on both sides of the inner wall of the reaction tower, dividing the interior space of the tower into a continuous serpentine channel. The spray circulation system includes a circulation pump and several perforated transparent spray pipes, each of which is positioned above one of the LED light sources and on the same side of the inner wall of the reaction tower. This invention uses a single-wavelength LED light source, provides mild reaction conditions, and achieves high reaction efficiency, making it suitable for an integrated photo-oxidation and hydrolysis reaction system for producing fluorinated acids from chlorofluorocarbons containing the RCHCl2 structure.

Description

Technical Field

[0001] This invention relates to the field of photo-oxidation reaction device technology, specifically to an integrated photo-oxidation and hydrolysis reaction device and its application. Background Technology

[0002] Photo-oxidation reactions offer advantages such as being environmentally friendly, technologically advanced, and cost-effective, and have broad application prospects. In recent years, their application in the fluorochemical industry has become increasingly widespread. They can be used in a one-step process to prepare fluorinated acyl chloride systems such as trifluoroacetyl chloride, difluoroacetyl chloride, and difluorochloroacetyl chloride. The specific reaction formula is as follows:

[0003]

[0004] As the core equipment in the photo-oxidation process, the design of the photo-reaction device has a significant impact on the photo-oxidation reaction process.

[0005] CN109180466A discloses a method for the photo-oxidative preparation of haloacetyl chloride. The reactor contains a quartz cold trap, which consists of a quartz inner shell and a quartz reaction tower. A light source is housed inside the quartz inner shell. A double-layer cold trap jacket is formed between the quartz inner shell and the quartz reaction tower, and the jacket is filled with a circulating filter liquid that filters out ultraviolet light with wavelengths less than 300 nm generated by the light source. This method uses a high-pressure mercury lamp, which generates significant heat and consumes a lot of energy. Furthermore, because the effective radiation radius of the light source is short, using a quartz cold trap to cool the high-pressure mercury lamp results in the light being blocked within the cold trap, reducing the actual effective irradiation area of ​​the light source.

[0006] CN101735034A discloses a method for preparing trifluoroacetyl chloride by using Cl2 as a photoinitiator and R123 reacting with O2 in a liquid-phase photo-oxidation reaction. This method employs a liquid-phase autoclave and a high-pressure mercury lamp, resulting in high power consumption and cooling costs. Furthermore, this method is a discontinuous reaction, making it difficult to achieve large-scale production.

[0007] CN101747176A discloses a method for preparing trifluoroacetyl chloride from a trifluoroethane chlorination mixture (trifluoromonochloroethane, trifluorodichloroethane, and trifluorotrichloroethane). In the presence of Cl2, the chlorination mixture undergoes a photochemical oxidation reaction with O2 under mercury lamp radiation, achieving a trifluoroacetyl chloride selectivity of 91%. This method uses a high-pressure mercury lamp and also faces problems such as high energy consumption and low photoreaction efficiency, as well as low product selectivity.

[0008] The photo-oxidation processes described in the patents reported above use traditional high-pressure mercury lamps, which generate significant heat, consume a lot of energy, are difficult to control in terms of system temperature, are prone to photochlorination side reactions, and require low luminous efficacy for effective photo-oxidation, making large-scale production difficult. Generally, photo-oxidation and hydrolysis reactions are carried out in different reactors; photo-oxidation is typically less efficient and requires multiple hydrolysis towers for the hydrolysis reaction.

[0009] In view of this, the present invention is hereby proposed. Summary of the Invention

[0010] The purpose of this invention is to provide an integrated photo-oxidation and hydrolysis reaction apparatus and its application. This invention provides a photo-oxidation apparatus that uses a single-wavelength LED light source, operates under mild reaction conditions, and has high reaction efficiency. A spray system is also installed within the reaction apparatus to simultaneously carry out the hydrolysis reaction, making it a suitable integrated photo-oxidation and hydrolysis reaction apparatus for the industrial production of fluorinated acids.

[0011] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted:

[0012] In a first aspect, the present invention provides an integrated photo-oxidation and hydrolysis reaction device, which includes a reaction tower, a light source system, and a spray circulation system.

[0013] The light source system includes several LED light sources, which are interlaced and parallel to each other on both sides of the inner wall of the reaction tower, dividing the interior space of the reaction tower into a continuous serpentine channel.

[0014] The spray circulation system includes a circulation pump and several perforated transparent spray pipes, with each perforated transparent spray pipe positioned above one of the LED light sources and on the same side of the inner wall of the reaction tower.

[0015] Preferably, each of the LED light sources includes a glass sleeve and a light source rod disposed in the inner cavity of the glass sleeve. The light source rod includes a heat-conducting rod and a plurality of LED beads; wherein the LED beads are fixedly connected to the outside of the heat-conducting rod.

[0016] Preferably, each of the LED light sources further includes a sealing connector, which is used via a flange to seal the outer surface of the glass tube and the outer wall of the reaction tower.

[0017] Preferably, the power of each LED light source is 30-180W, more preferably 40-170W.

[0018] Preferably, the emission wavelength of each LED light source is independently 200-500nm, and more preferably 300-490nm.

[0019] Preferably, the light source system includes 10 to 60 LED light sources.

[0020] Preferably, the distance between each adjacent LED light source is 15-65cm, and more preferably 20-60cm.

[0021] Preferably, the length of the glass sleeve is 55-100% of the inner diameter of the reaction tower body, and more preferably 60-95%.

[0022] Preferably, the spray circulation system further includes a circulation pipeline disposed outside the reaction tower, and the circulation pipeline is used to connect the circulation pump and several perforated transparent spray pipes;

[0023] Furthermore, the circulating pump is connected to the liquid outlet on the side of the reaction tower. The spray circulation system first pumps the water-containing material in the bottom of the reaction tower through the circulating pump and the circulating pipeline into each perforated transparent spray pipe for spraying the liquid phase water-containing material and forming a droplet mist.

[0024] Preferably, the perforated transparent spray pipe is a spray pipe with holes on all four sides.

[0025] Preferably, the inner diameter of the perforated transparent spray pipe is 3 to 20 mm.

[0026] Preferably, the aperture of the perforated transparent spray pipe is 0.2–0.6 mm, and the perforation density is 5–20 per cm. 2 .

[0027] Preferably, the material of the perforated transparent spray pipe is selected from any one or a combination of at least two of PFA, FEP, PVF, ETFE, PCTFE, ECTFE or Teflon AF, and is preferably PFA and / or FEP.

[0028] Preferably, the water at the bottom of the reaction tower is selected from any one or a combination of at least two of deionized water, distilled water, or softened water, with deionized water being the most preferred.

[0029] Preferably, the perforated transparent spray pipes are evenly distributed above the light source system on the same side of the reaction tower body, and the second and lower groups of perforated transparent spray pipes from top to bottom are located in the middle of two adjacent LED light sources.

[0030] Preferably, the reaction tower is cylindrical in shape.

[0031] Preferably, the height of the reaction tower is ≥10m.

[0032] Preferably, the material of the reaction tower is selected from either corrosion-resistant metal lining polytetrafluoroethylene or enamel.

[0033] Preferably, the reaction tower includes a gaseous feed inlet, a gas outlet, a bottom drain outlet, and a water makeup inlet;

[0034] The gaseous feed inlet is located on one side of the lower part of the reaction tower and above the liquid level in the bottom of the reaction tower; the gas outlet is located at the top of the reaction tower; the bottom drain outlet is located at the bottom of the reaction tower; and the water inlet is located on the other side of the lower part of the reaction tower.

[0035] Preferably, the upper part of the reaction tower is provided with a condensation system, which includes a condenser, a cold material inlet, and a cold material outlet.

[0036] Preferably, the condenser is made of any one of silicon carbide, graphite, or enamel.

[0037] Preferably, the reactor vessel is equipped with a heating system, which includes a heating jacket, a hot material inlet, and a hot material outlet, and the heating jacket covers the outside of the reactor vessel.

[0038] In a second aspect, the present invention provides an application of the integrated photo-oxidation and hydrolysis reaction apparatus as described in the first aspect in the preparation of fluorinated acyl chlorides by photo-oxidation reaction and the preparation of fluorinated acids by hydrolysis reaction.

[0039] Preferably, the fluorinated acyl chloride includes any one or a combination of at least two of trifluoroacetyl chloride, difluoroacetyl chloride, or difluorochloroacetyl chloride.

[0040] Preferably, the fluorinated acid includes any one or a combination of at least two of trifluoroacetic acid, difluoroacetic acid, or difluorochloroacetic acid.

[0041] Thirdly, the present invention provides a continuous production method for fluorinated acid, wherein the continuous production method for fluorinated acid is carried out using an integrated photo-oxidation and hydrolysis reaction apparatus as described in the first aspect, and specifically includes the following steps:

[0042] A chlorofluorocarbon, oxygen, and chlorine are introduced into the reaction tower. Under the illumination of the LED light source, chlorine acts as a photoinitiator, causing the chlorofluorocarbon and oxygen to undergo a photo-oxidation reaction to obtain fluorinated acyl chloride. Simultaneously, a liquid-phase aqueous material is sprayed into the reaction tower through the perforated transparent spray pipe, causing the liquid-phase aqueous material to form droplets that come into countercurrent contact with the fluorinated acyl chloride to undergo a hydrolysis reaction, yielding crude fluorinated acid. After discharge, the crude product is separated and purified to obtain the fluorinated acid product.

[0043] Preferably, the chlorofluorocarbon includes any one or a combination of at least two of CF3CHCl2 (R123), CHF2CHCl2 (R132a), or CClF2CHCl2 (R122).

[0044] Preferably, the molar ratio of the chlorofluorocarbon, oxygen, and chlorine is 1:(0.5-1.5):(0.05-0.15), more preferably 1:(0.6-1.4):(0.06-0.14).

[0045] Preferably, the temperature of the photo-oxidation reaction is 10–100°C, more preferably 20–90°C; and the pressure of the photo-oxidation reaction is 0–0.35 MPa, more preferably 0.05–0.30 MPa.

[0046] Preferably, the total spraying rate of the liquid phase water-containing material is 10-110 kg / h, and more preferably 20-100 kg / h.

[0047] Preferably, during the hydrolysis reaction, water needs to be added to the bottom of the reaction tower while crude fluoride product is discharged from the bottom outlet, and the inflow and outflow of the two are basically balanced.

[0048] Preferably, the water replenishment rate is 50–180 kg / h, and more preferably 80–150 kg / h.

[0049] Preferably, the rate of discharge of the crude fluoride product is 50-180 kg / h, and more preferably 80-150 kg / h.

[0050] In this invention, the photo-oxidation and hydrolysis reactions are coupled, rather than simply performing the two reactions within a single reaction. For this integrated reaction device, when chlorofluorocarbons undergo photo-oxidation to generate fluorinated acyl chlorides and HCl, a fluorinated acyl chloride hydrolysis reaction simultaneously occurs within the device. Meanwhile, hydrogen chloride is absorbed by the sprayed water. With the consumption of the photo-oxidation products and the dissolution of hydrogen chloride, a fully coupled photo-oxidation and hydrolysis reaction is achieved, thereby promoting and driving the efficient execution of the photo-oxidation reaction. Furthermore, because this invention uses multi-stage spray pipes and has a condenser at the top, after the fluorinated acyl chlorides are generated in situ during the photo-oxidation reaction, the lower concentration of fluorinated acyl chlorides undergoes rapid and complete hydrolysis through counter-current contact with the sprayed atomized water-containing material. This significantly improves the production capacity of the photo-oxidation product fluorinated acyl chlorides and the hydrolysis product fluorinated acid while maintaining a high conversion rate of chlorofluorocarbons.

[0051] Compared with the prior art, the present invention has the following beneficial effects:

[0052] (1) The present invention uses LED light source to replace the traditional high-pressure mercury lamp. The light emission wavelength is single, the heat generation is low, and the energy consumption is low. Multiple sets of LED light sources located in the device can provide efficient and uniform illumination to the reaction materials. The photo-oxidation conversion rate and selectivity are good, and the reaction process is controllable.

[0053] (2) The present invention uses a perforated transparent spray tube, which occupies little space, can achieve full mass and heat transfer of materials, does not affect the distribution of light in the device, removes the reaction heat and light source heat during the photo-oxidation process, and absorbs the hydrochloric acid produced by the reaction, which is beneficial to the reaction, achieves effective control of the reaction temperature, reduces the safety risks in the photo-oxidation reaction, and extends the service life of the light source.

[0054] (3) The present invention can achieve continuous production of fluorinated acids such as trifluoroacetic acid, difluoroacetic acid, and difluorochloroacetic acid through efficient photo-oxidation reaction. Compared with separate photoreactors and hydrolysis towers, photo-oxidation reaction and hydrolysis reaction are more efficient and help save equipment costs. Attached Figure Description

[0055] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0056] Figure 1 A diagram of the integrated photo-oxidation and hydrolysis reaction apparatus provided by the present invention.

[0057] Among them, 1 is the reaction tower, 2 is the gaseous raw material inlet, 3 is the gas outlet, 4 is the tower bottom drain outlet, 5 is the water replenishment inlet, 6 is the heating jacket, 7 is the condenser, 8 is the hot material inlet, 9 is the hot material outlet, 10 is the cold material inlet, 11 is the cold material outlet, 12 is the LED lamp bead, 13 is the heat conduction rod, 14 is the glass sleeve, 15 is the circulating pump, 16 is the perforated transparent spray pipe, and 17 is the circulation pipeline.

[0058] Figure 2 This is a partially enlarged view of the perforated transparent spray pipe provided by the present invention. Detailed Implementation

[0059] Unless otherwise defined herein, scientific and process terms used in conjunction with this invention should have the meanings commonly understood by one of ordinary skill in the art. The meaning and scope of terms should be clear; however, in any case of potential ambiguity, the definitions provided herein take precedence over any dictionary or foreign definitions. In this application, unless otherwise stated, the use of "or" means "and / or". Furthermore, the use of the term "comprising" and other forms is non-limiting.

[0060] It should be noted that specific details are set forth in the following description to provide a full understanding of the invention. However, the invention can be practiced in many ways other than those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0061] It should be noted that, in the following description, the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0062] Furthermore, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0063] The embodiments and examples of the present invention will be described in detail below. However, those skilled in the art will understand that the following embodiments and examples are for illustrative purposes only and should not be considered as limiting the scope of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention. Unless otherwise specified, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0064] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted:

[0065] In a first aspect, the present invention provides an integrated photo-oxidation and hydrolysis reaction apparatus, such as... Figure 1 As shown, the integrated photo-oxidation and hydrolysis reaction device includes a reaction tower 1, a light source system, and a spray circulation system;

[0066] The light source system includes several LED light sources, which are interlaced and parallel to each other on both sides of the inner wall of the reaction tower 1, dividing the inner space of the reaction tower 1 into a continuous serpentine channel.

[0067] The spray circulation system includes a circulation pump 15 and several perforated transparent spray pipes 16, with each perforated transparent spray pipe 16 positioned above one of the LED light sources and on the same side of the inner wall of the reaction tower 1.

[0068] In this invention, a transparent spray pipe with uniformly distributed fine holes is inserted parallel to each light source on the same side above it; the spray circulation system pumps the water-containing material at the bottom of the device into each transparent spray pipe for hydrolysis reaction, while absorbing the byproduct hydrochloric acid and reducing the temperature of the light source.

[0069] As an optional implementation method, such as Figure 1 As shown, each of the LED light sources includes a glass sleeve and a light source rod disposed in the inner cavity of the glass sleeve 14. The light source rod includes a heat-conducting rod 13 and a plurality of LED beads 12; wherein, the LED beads 12 are fixedly connected to the outside of the heat-conducting rod 13.

[0070] It should be noted that, taking into account the advantages of LED light sources such as low heat generation, high luminous efficiency, and narrow emission wavelength range, the present invention uses LED light sources. Each LED light source consists of an LED bead, a heat-conducting rod, and a glass sleeve. The LED bead is fixedly connected to the outside of the heat-conducting rod, which is beneficial for heat dissipation of the light source. The glass sleeve is placed on the outside of the LED bead to isolate the LED bead from the reactants.

[0071] As an optional implementation, each of the LED light sources also includes a sealing connector, which is used via a flange to seal the outer surface of the glass tube and the outer wall of the reaction tower.

[0072] As an optional implementation, the power of each LED light source is independently 30 to 180W, for example, it can be 30W, 40W, 50W, 60W, 70W, 80W, 90W, 100W, 110W, 120W, 130W, 140W, 150W, 160W, 170W, 180W, etc., preferably 40 to 170W.

[0073] It should be noted that this invention reveals a correlation between the power of the LED light source and the feed rate to maintain optimal photo-oxidation efficiency. When the feed rate changes, the power of the LED light source must be adjusted simultaneously to maintain a constant ratio between the LED light source power and the feed rate. Preferably, the power of the LED light source is continuously adjustable between 30 and 180 W to provide illumination to the reactants in the reactor, promoting the photo-oxidation reaction. More preferably, the light source power is 40 to 170 W, and preferably increases linearly with increasing feed rate.

[0074] As an optional implementation, the emission wavelength of each LED light source is independently 200-500nm, for example, it can be 200nm, 210nm, 220nm, 230nm, 240nm, 250nm, 260nm, 270nm, 280nm, 290nm, 300nm, 310nm, 320nm, 330nm, 340nm, 350nm, 360nm, 370nm, 380nm, 390nm, 400nm, 410nm, 420nm, 430nm, 440nm, 450nm, 460nm, 470nm, 480nm, 490nm, 500nm, etc., preferably 300-490nm.

[0075] It should be noted that, according to the characteristics of photo-oxidation reactions, shorter wavelengths result in higher energy. Light source wavelengths below 300 nm can cause CF bond breakage, generating more byproducts and also producing fluoride ions that exacerbate equipment corrosion. Wavelengths above 500 nm, however, cannot effectively generate chlorine free radicals from chlorine gas, making the photo-oxidation reaction difficult to proceed effectively. Furthermore, according to radiation characteristics, shorter wavelengths of light have poorer penetration, affecting reaction efficiency. Therefore, the emission wavelength of the LED light source is 200–500 nm, preferably 300–490 nm.

[0076] As an optional implementation, the difference between the dominant wavelength and the peak wavelength is 3 to 8 nm, for example, it can be 3 nm, 3.5 nm, 4 nm, 4.5 nm, 5 nm, 5.5 nm, 6 nm, 6.5 nm, 7 nm, 7.5 nm, 8 nm, etc., and more preferably 4 to 7 nm.

[0077] As an optional implementation, the half-peak bandwidth is 14 to 20 nm, for example, it can be 14 nm, 14.5 nm, 15 nm, 15.5 nm, 16 nm, 16.5 nm, 17 nm, 17.5 nm, 18 nm, 18.5 nm, 19 nm, 19.5 nm, 20 nm, etc., and is more preferably 15 to 19 nm.

[0078] As an optional implementation, the light source system includes 10 to 60 LED light sources, for example, 10, 12, 14, 15, 16, 18, 20, 22, 24, 25, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 55, 56, 58, 60, etc.

[0079] It should be noted that the research of this invention found that the number of light sources is directly related to the photoreaction efficiency. It is better to set 10 to 60 LED light sources in the reaction tower. A lower number of light sources will result in a lower photoreaction efficiency and an unsatisfactory photooxidation conversion rate. A higher number of light sources will result in an excessively tall photoreactor, which is inconvenient for processing, design and installation. A more preferred solution is to set 20 to 50 LED light sources, which can simultaneously achieve good photoreaction efficiency and design, processing and installation.

[0080] As an optional implementation, the distance between each adjacent LED light source is 15 to 65 cm, for example, it can be 15 cm, 20 cm, 25 cm, 30 cm, 35 cm, 40 cm, 45 cm, 50 cm, 55 cm, 60 cm, 65 cm, etc., preferably 20 to 60 cm.

[0081] It should be noted that this invention has found that when the radiation flux density is greater than 2 mW / cm², 2 Only when the light source and radiant flux density are 2 mW / cm² can the photo-oxidation reaction be effectively initiated. 2 The distance between adjacent light sources is the effective radiation radius. If the distance between adjacent light sources is too small, the utilization rate of the light source will be too low; if the distance between adjacent light sources is too large, the utilization rate of the space inside the reactor will be insufficient, affecting the space-time yield of the reactor. Therefore, in order to make full use of the light source and reduce the space inside the reactor, the distance between adjacent light sources is between 15 and 65 cm, and the preferred distance is 20 to 60 cm.

[0082] As an optional implementation, the length of the glass sleeve is 55% to 100% of the inner diameter of the reaction tower body, for example, it can be 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 100%, etc., preferably 60% to 95%.

[0083] It should be noted that the present invention has found that multiple light sources are inserted into the reaction tower body at intervals on both sides of the main body of the device. Therefore, in order to make full use of the internal space of the reactor, the length of the glass tube is 55 to 100% of the inner diameter of the reactor, preferably 60 to 95%.

[0084] As an optional implementation method, such as Figure 1As shown, the spray circulation system also includes a circulation pipeline 17 located outside the reaction tower. The circulation pipeline 17 is used to connect the circulation pump 15 and several perforated transparent spray pipes 16. The circulation pump 15 is connected to the side outlet of the bottom of the reaction tower 1. The spray circulation system first pumps the water-containing material in the bottom of the reaction tower through the circulation pump and the circulation pipeline into each perforated transparent spray pipe 16 to spray the liquid phase water-containing material and form a droplet mist.

[0085] It should be noted that the spray circulation system described in this invention includes a circulation pump, a perforated transparent spray pipe, and an external circulation pipeline for the reaction device. The spray circulation system draws the water-containing material at the bottom of the device through the circulation pump and the external circulation pipeline into each perforated transparent spray pipe for hydrolysis reaction. The water molecules formed in droplet form and the fluorinated acyl chloride generated by the photo-oxidation reaction form a reverse contact. That is, this spray design makes the contact between the water-containing material and the fluorinated acyl chloride more sufficient. Most of the fluorinated acyl chloride is prepared into fluorinated acid through hydrolysis reaction, while absorbing the by-product hydrochloric acid and reducing the temperature of the light source.

[0086] As an optional implementation, the material of the perforated transparent spray pipe is selected from any one or a combination of at least two of PFA, FEP, PVF, ETFE, PCTFE, ECTFE or Teflon AF, preferably PFA and / or FEP.

[0087] It should be noted that the perforated transparent spray pipe is made of a material with good light transmittance, acid resistance, and swelling resistance. The perforated transparent spray pipe is evenly distributed on the same side of the main body of the device and located in the middle of the two light sources. This not only enables the uniform distribution of materials, but also allows the sprayed droplets of water-containing materials to undergo a reverse contact with the fluorinated acyl chloride generated by the photo-oxidation reaction, resulting in a hydrolysis reaction.

[0088] As an optional implementation method, such as Figure 2 As shown, the perforated transparent spray pipe is a spray pipe with holes on all four sides.

[0089] As an optional implementation, the inner diameter of the perforated transparent spray pipe is 3 to 20 mm, for example, it can be 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, 20 mm, etc.

[0090] As an optional implementation, the aperture of the perforated transparent spray pipe is 0.2–0.6 mm, for example, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, etc., and the distribution density of the perforations is 5–20 per cm. 2 For example, it could be 5 per cm 2, 6 per cm 2 , 7 per cm 2 , 8 per cm 2 , 9 per cm 2 , 10 per cm 2 , 11 per cm 2 , 12 per cm 2 , 13 per cm 2 , 14 per cm 2 , 15 per cm 2 , 16 per cm 2 , 17 per cm 2 , 18 per cm 2 , 19 per cm 2 , 20 per cm 2 etc.

[0091] It should be noted that in the FEP transparent spray pipe of the present invention with uniformly distributed fine holes, it is ensured to form droplet-like water molecules. If it is not within the above range and the sprayed water is in the form of liquid droplets, it is not conducive to the full mass transfer and heat transfer of the material, affecting the reaction effect; if the sprayed water is close to the aerosol state, since the reaction is an exothermic reaction, the vaporization of water is further intensified. At the top of the reactor tower, the amount of condensed and refluxed aerosol-like water decreases, and part of the water vapor is discharged with the tower top, affecting the hydrolysis reaction and further affecting the progress of the photooxidation reaction. At the same time, it is difficult for the sprayed aerosol-like water to play the role of reducing the temperature of the outer surface of the glass tube, affecting the heat dissipation of the light source and being not conducive to the long-term stable use of the light source. At the same time, due to the porous and transparent nature of the spray pipe itself and the small space it occupies, the influence on the light distribution in the reactor is small, and the photo-reaction effect is fully exerted. If an opaque spray pipe is used, it will affect the light distribution between the LEDs and reduce the photo-reaction efficiency.

[0092] As an optional implementation manner, the water at the bottom of the reaction tower is selected from any one or a combination of at least two of deionized water, distilled water or softened water, and preferably deionized water.

[0093] As an optional implementation manner, the porous transparent spray pipes are uniformly distributed above the light source system on the same side of the tower body of the reaction tower, and the second group and the following porous transparent spray pipes from top to bottom are located in the middle of two adjacent LED light sources.

[0094] It should be noted that the number of spray pipes supporting the integrated reaction device and the light source has an important impact on the efficient progress of the photooxidation reaction and the hydrolysis coupling reaction. When the number of transparent spray pipes enabled < 20, it is difficult to ensure sufficient hydrolysis reaction, and further affects the progress of the photooxidation reaction. When the number of transparent spray pipes enabled ≥ 20, it can ensure sufficient hydrolysis reaction, and further promote the efficient progress of the photooxidation and hydrolysis coupling reactions.

[0095] As an optional implementation, the reaction tower has a cylindrical shape.

[0096] As an optional implementation, the height of the reaction tower is ≥10m, for example, it can be 10m, 11m, 12m, 13m, 14m, 15m, etc.

[0097] It should be noted that the present invention has found that when the reactor height is ≥10m, multiple light sources and spray pipes can be evenly distributed, and a sufficient number of light sources and spray pipes can be guaranteed, which is conducive to ensuring sufficient photo-oxidation and hydrolysis coupling reactions. When the reactor height is too low, it is not enough to evenly install and distribute a suitable number of light sources and spray pipes, which will lead to a low conversion rate of photo-oxidation of chlorofluorocarbons and a low conversion rate of hydrolysis of fluorinated acyl chlorides.

[0098] As an optional implementation, the material of the reaction tower is selected from either corrosion-resistant metal lining polytetrafluoroethylene or enamel.

[0099] As an optional implementation method, such as Figure 1 As shown, the reaction tower 1 includes a gaseous feed inlet 2, a gas outlet 3, a bottom drain outlet 4, and a water inlet 5; wherein, the gaseous feed inlet 2 is located on one side of the lower part of the reaction tower 1 and is located above the liquid surface of the bottom of the reaction tower 1; the gas outlet 3 is located at the top of the reaction tower 1; the bottom drain outlet 4 is located at the bottom of the reaction tower 1; and the water inlet 5 is located on the other side of the lower part of the reaction tower 1.

[0100] It should be noted that the gas outlet 3 is located at the top of the reaction tower and is used to discharge unreacted oxygen, chlorine and a small amount of byproduct hydrogen chloride.

[0101] As an optional implementation method, such as Figure 1 As shown, a condensation system is provided at the top of the reaction tower, and the condensation system includes: a condenser 7, a cold material inlet 10, and a cold material outlet 11.

[0102] As an optional implementation, the condenser is made of any one of silicon carbide, graphite, or enamel.

[0103] As an optional implementation method, such as Figure 1 As shown, the reactor vessel of the reaction tower 1 is equipped with a heating system, which includes a heating jacket 6, a hot material inlet 8 and a hot material outlet 9, and the heating jacket 6 covers the outside of the reactor vessel of the reaction tower 1.

[0104] It should be noted that the reaction tower includes the aforementioned heating system, condensation system, raw material inlet, top outlet, and bottom drain. The bottom drain is used to continuously discharge crude fluoroacid, whose main components include aqueous fluoroacid, hydrochloric acid, and a small amount of unreacted chlorofluorocarbon raw materials, ensuring stable operation of the unit. The bottom of the reaction tower is used to store liquid-phase aqueous materials, and the medium in the jacket of the heating system is used to regulate the water temperature. The tower body encloses the interior of the reaction unit into a closed space. The condensation system is used for condensing and refluxing unreacted chlorofluorocarbon raw materials for continued photo-oxidation reaction and for refluxing unreacted fluoroacyl chlorides for continued hydrolysis reaction. The raw material inlet is located on the lower side of the reaction tower body, above the water surface.

[0105] In a second aspect, the present invention provides an application of the integrated photo-oxidation and hydrolysis reaction apparatus as described in the first aspect in the preparation of fluorinated acyl chlorides by photo-oxidation reaction and the preparation of fluorinated acids by hydrolysis reaction.

[0106] As an optional implementation, the fluorinated acyl chloride includes any one or a combination of at least two of trifluoroacetyl chloride, difluoroacetyl chloride, or difluorochloroacetyl chloride.

[0107] As an optional implementation, the fluorinated acid includes any one or a combination of at least two of trifluoroacetic acid, difluoroacetic acid, or difluorochloroacetic acid.

[0108] It should be noted that the present invention also provides an application of the above-mentioned integrated photo-oxidation and hydrolysis reaction, which is used to prepare fluorinated acyl chlorides such as trifluoroacetyl chloride, difluoroacetyl chloride, and difluorochloroacetyl chloride by photo-oxidation reaction of fluorochloroalkanes containing the RCHCl2 structure such as CF3CHCl2, CHF2CHCl2, and CClF2CHCl2 and oxygen under the action of LED light irradiation and photoinitiator chlorine gas.

[0109] It should be noted that the photo-oxidation and hydrolysis integrated reaction device described in this invention is used for the photo-oxidation reaction of chlorofluorocarbons containing the RCHCl2 structure, such as CF3CHCl2, CHF2CHCl2, and CClF2CHCl2. Because the light source is a single-wavelength LED light source, selecting a suitable wavelength makes it difficult for the CF bond to break, and the reaction temperature is relatively low, minimizing the occurrence of chlorination side reactions. This results in a high space-time yield and good selectivity for fluorinated acyl chlorides. Using a perforated transparent spray tube to spray a mist of water-containing material and the fluorinated acyl chloride in reverse contact allows for hydrolysis, while simultaneously absorbing the hydrogen chloride produced in the reaction, which is beneficial for the reaction and removes the heat of reaction, reducing the temperature of the light source. Furthermore, the transparent spray tube does not affect the light distribution within the device, ensuring efficient photo-oxidation and enabling the efficient conversion of chlorofluorocarbons containing the RCHCl2 structure, such as CF3CHCl2, CHF2CHCl2, and CClF2CHCl2, into fluorinated acyl chlorides.

[0110] It is important to note that the integrated photo-oxidation and hydrolysis reaction device described in this invention is a coupled design of the photo-oxidation and hydrolysis reactions, not a simple combination of two reactions within a single reaction. In this integrated reaction device, when chlorofluorocarbons undergo photo-oxidation to generate fluorinated acyl chlorides and HCl, a fluorinated acyl chloride hydrolysis reaction simultaneously occurs within the device. At the same time, hydrogen chloride is absorbed by the sprayed water. With the consumption of photo-oxidation products and the dissolution of hydrogen chloride, a fully coupled photo-oxidation and hydrolysis reaction is achieved, thereby promoting and driving the efficient execution of the photo-oxidation reaction. Furthermore, because this invention uses multi-stage spray pipes and has a condenser at the top, after the fluorinated acyl chloride is generated in situ during the photo-oxidation reaction, the lower concentration of fluorinated acyl chloride, through counter-current contact with the sprayed atomized water-containing material, can undergo a rapid and complete hydrolysis reaction. While maintaining a high conversion rate of chlorofluorocarbons, this significantly improves the production capacity of both the photo-oxidation product (fluorinated acyl chloride) and the hydrolysis product (fluorinated acid).

[0111] Thirdly, the present invention provides a continuous production method for fluorinated acid, wherein the continuous production method for fluorinated acid is carried out using an integrated photo-oxidation and hydrolysis reaction apparatus as described in the first aspect, and specifically includes the following steps:

[0112] A chlorofluorocarbon, oxygen, and chlorine are introduced into the reaction tower. Under the illumination of the LED light source, chlorine acts as a photoinitiator, causing the chlorofluorocarbon and oxygen to undergo a photo-oxidation reaction to obtain fluorinated acyl chloride. Simultaneously, a liquid-phase aqueous material is sprayed into the reaction tower through the perforated transparent spray pipe, causing the liquid-phase aqueous material to form droplets that come into countercurrent contact with the fluorinated acyl chloride to undergo a hydrolysis reaction, yielding crude fluorinated acid. After discharge, the crude product is separated and purified to obtain the fluorinated acid product.

[0113] As an optional implementation, the chlorofluorocarbon includes any one or a combination of at least two of CF3CHCl2, CHF2CHCl2, or CClF2CHCl2.

[0114] As an optional implementation, the molar ratio of the chlorofluorocarbon, oxygen, and chlorine is 1:(0.5-1.5):(0.05-0.15); wherein, "0.5-1.5" can be, for example, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, etc.; "0.05-0.15" can be, for example, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, etc.; the preferred molar ratio of the chlorofluorocarbon, oxygen, and chlorine is 1:(0.6-1.4):(0.06-0.14).

[0115] As an optional implementation, the temperature of the photo-oxidation reaction is 10 to 100°C, for example, it can be 10°C, 20°C, 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, etc., preferably 20 to 90°C.

[0116] It should be noted that the temperature of the photo-oxidation reaction is preferably lower than the boiling point of the corresponding chlorofluorocarbons. Taking CF3CHCl2, CHF2CHCl2, and CClF2CHCl2 as examples, the boiling points of these three chlorofluorocarbons are 28℃, 60℃, and 72℃, respectively. Therefore, the preferred reaction temperature is lower than the boiling point of the above raw materials, which is conducive to the recycling of unreacted raw materials and the full mass and heat transfer of the hydrolysis reaction. Hot water heating is preferably used for the tower jacket.

[0117] As an optional implementation, the pressure of the photo-oxidation reaction is 0 to 0.35 MPa, for example, 0 MPa, 0.02 MPa, 0.04 MPa, 0.05 MPa, 0.06 MPa, 0.08 MPa, 0.1 MPa, 0.12 MPa, 0.15 MPa, 0.17 MPa, 0.2 MPa, 0.22 MPa, 0.25 MPa, 0.28 MPa, 0.3 MPa, 0.32 MPa, 0.35 MPa, etc., preferably 0.05 to 0.30 MPa.

[0118] It should be noted that the photooxidation reaction of chlorofluorocarbons containing the RCHCl2 structure, such as CF3CHCl2, CHF2CHCl2, and CClF2CHCl2, is a reaction that increases volume and releases a large amount of heat. At the same time, the pressure resistance of the glass tube is limited. Higher reaction pressure is conducive to the condensation and reflux of unreacted raw materials, which improves the single-pass conversion rate. If the pressure is too low, more unreacted raw materials will be carried out, which will lead to a decrease in the conversion rate. If the pressure is too high, the glass tube may break and leak.

[0119] As an optional implementation, the total spraying rate of the water-containing material is 10-110 kg / h, for example, it can be 10 kg / h, 20 kg / h, 30 kg / h, 40 kg / h, 50 kg / h, 60 kg / h, 70 kg / h, 80 kg / h, 90 kg / h, 100 kg / h, 110 kg / h, etc., preferably 20-100 kg / h.

[0120] It is worth noting that the research found that the spray volume of the recycled material significantly affects the results of the photo-oxidation and hydrolysis coupling reaction. When the spray volume of the recycled material is small, the insufficient water supply for the hydrolysis reaction leads to incomplete hydrolysis, which in turn affects the efficiency of the photo-oxidation reaction and the production capacity of the fluorinated acid. When the spray volume of the recycled material is large, the excessive water content of the material will absorb some light, and the material is prone to generating bubbles in the reactor, causing light to be constantly reflected between the bubbles, thus reducing the light transmittance between the materials.

[0121] As an optional implementation, during the hydrolysis reaction, water needs to be added to the bottom of the reaction tower while the crude fluoride product is discharged from the bottom outlet, and the inflow and outflow of the two are basically balanced.

[0122] It is important to note that the bottom of the reaction tower needs to be replenished with fresh water while simultaneously discharging crude fluoride to maintain a stable liquid level and balance between inflow and outflow.

[0123] As an optional implementation, the water replenishment rate is 50-180 kg / h, for example, it can be 50 kg / h, 60 kg / h, 70 kg / h, 80 kg / h, 90 kg / h, 100 kg / h, 110 kg / h, 120 kg / h, 130 kg / h, 140 kg / h, 150 kg / h, 160 kg / h, 170 kg / h, 180 kg / h, etc., preferably 80-150 kg / h.

[0124] As an optional implementation, the rate of discharge of the aqueous material containing the crude fluoride product is 50-180 kg / h, for example, it can be 50 kg / h, 60 kg / h, 70 kg / h, 80 kg / h, 90 kg / h, 100 kg / h, 110 kg / h, 120 kg / h, 130 kg / h, 140 kg / h, 150 kg / h, 160 kg / h, 170 kg / h, 180 kg / h, etc., preferably 80-150 kg / h.

[0125] It should be noted that the research of this invention found that the balance rate control of water replenishment and bottom liquid discharge in the reaction tower also has a significant impact on the coupled photo-oxidation and hydrolysis reactions. When the water replenishment rate and bottom liquid discharge rate are controlled at a slower level, the fluoric acid and hydrochloric acid in the bottom and circulating materials gradually accumulate, and the water content gradually decreases, which will inhibit the hydrolysis reaction and photo-oxidation. When the water replenishment rate and bottom liquid discharge rate are controlled at a faster level, it will result in a lower content of crude fluoric acid, increasing the subsequent separation cost and the cost of waste disposal.

[0126] The present invention will be further illustrated below with specific embodiments and comparative examples. However, it should be understood that these embodiments are merely for the purpose of more detailed illustration and should not be construed as limiting the present invention in any way.

[0127] Example 1

[0128] This embodiment provides an integrated photo-oxidation and hydrolysis reaction device. Figure 1 A schematic diagram of an integrated photo-oxidation and hydrolysis reaction device is shown, which includes a reaction tower 1, a light source system, and a spray circulation system.

[0129] The reaction tower 1 includes a gaseous feed inlet 2, a gas outlet 3, a bottom drain outlet 4, a water inlet 5, a heating jacket 6, a condenser 7, a hot material inlet 8, a hot material outlet 9, a cold material inlet 10, and a cold material outlet 11. The reaction tower body is a cylinder with an inner diameter of 600 mm and a height of 12 m, constructed of corrosion-resistant carbon steel lined with polytetrafluoroethylene. The condenser is made of silicon carbide, and the bottom vessel of the reaction unit is used to store materials containing water.

[0130] The light source system comprises 20 LED light sources, which are staggered and parallel to each other on both sides of the inner wall of the reaction tower 1, dividing the interior space of the reaction tower 1 into a continuous serpentine channel. Each LED light source includes a glass sleeve and a light source rod disposed within the inner cavity of the glass sleeve 14. The light source rod includes a heat-conducting rod 13 and several LED beads 12. The LED beads 12 are fixedly connected to the outside of the heat-conducting rod 13, and the glass sleeve is fitted over the LED beads to isolate the LED light source from the reactants. The rated power of the light source is 120W, the wavelength is 425nm, the glass tube length is 580mm, and the distance between the centers of adjacent light sources is 50cm to ensure sufficient illumination in all areas inside the reactor.

[0131] The spray system includes a circulation pump 15, a perforated transparent spray pipe 16, and a circulation pipeline 17. A uniformly distributed FEP transparent spray pipe with fine holes is inserted parallel above each light source (the inner diameter of the spray pipe is 10mm, the diameter of the opening is 0.4mm, and the distribution density of the holes is 12 holes / cm²). 2 The device consists of 20 perforated transparent spray pipes distributed between two light sources on the same side of the main body. The spray circulation system pumps water from the bottom of the device into each transparent spray pipe. By opening the discharge valves of all 20 spray pipes, the water-containing material is sprayed evenly for hydrolysis reaction, while absorbing the byproduct hydrochloric acid and reducing the temperature of the light source.

[0132] Example 2

[0133] This embodiment provides an integrated photo-oxidation and hydrolysis reaction device, which differs from Embodiment 1 only in that it uses an LED light source with a wavelength of 375nm, while the other settings are the same as in Embodiment 1.

[0134] Example 3

[0135] This embodiment provides an integrated photo-oxidation and hydrolysis reaction device, which differs from Embodiment 1 only in that it uses an LED light source with a wavelength of 400nm, while the other settings are the same as in Embodiment 1.

[0136] Example 4

[0137] This embodiment provides an integrated photo-oxidation and hydrolysis reaction device, which differs from Embodiment 1 only in that it uses an LED light source with a wavelength of 450nm, while the other settings are the same as in Embodiment 1.

[0138] Example 5

[0139] This embodiment provides an integrated photo-oxidation and hydrolysis reaction device, which differs from Embodiment 1 only in that it uses an LED light source with a wavelength of 475nm, while the other settings are the same as in Embodiment 1.

[0140] Example 6

[0141] This embodiment provides an integrated photo-oxidation and hydrolysis reaction device, which differs from Embodiment 1 only in that it uses an LED light source with a wavelength of 490nm, while the other settings are the same as in Embodiment 1.

[0142] Example 7

[0143] This embodiment provides an integrated photo-oxidation and hydrolysis reaction device. The only difference from Embodiment 1 is that it uses a uniformly distributed FEP transparent spray pipe with relatively large pores (the opening diameter of the spray pipe is 0.8 mm), and the sprayed material is mainly in the form of droplets. Other settings are the same as in Embodiment 1.

[0144] Example 8

[0145] This embodiment provides an integrated photo-oxidation and hydrolysis reaction device. The only difference from Embodiment 1 is that it uses a uniformly distributed FEP transparent spray pipe with fine pores (the pore diameter of the spray pipe is 0.1 mm), and the sprayed material is mainly in aerosol state. Other settings are the same as in Embodiment 1.

[0146] Comparative Example 1

[0147] This comparative example provides an integrated photo-oxidation and hydrolysis reaction device, which differs from Example 1 only in that a high-pressure mercury lamp is used instead of an LED lamp, while the other settings are the same as in Example 1.

[0148] Comparative Example 2

[0149] This comparative example provides an integrated photo-oxidation and hydrolysis reaction device. The only difference from Example 1 is that an opaque PTFE perforated spray pipe is used instead of a transparent FEP perforated spray pipe. All other settings are the same as in Example 1.

[0150] Comparative Example 3

[0151] This comparative example provides an integrated photo-oxidation and hydrolysis reaction device. The only difference from Example 1 is that a spray pipe with only downward-facing openings is used instead of a spray pipe with openings on all four sides. All other settings are the same as in Example 1.

[0152] Comparative Example 4

[0153] This comparative example provides a photo-oxidation-hydrolysis system, which differs from Example 1 only in that the internal spray circulation system is no longer installed in the reaction device. That is, the reaction device only includes a reaction tower and a light source system. Instead, a primary hydrolysis tower is connected to the outside of the reaction device. The reaction device and the primary hydrolysis tower are connected by a conveying pipeline, and the reaction products are conveyed to the primary hydrolysis tower for hydrolysis through the conveying pipeline.

[0154] Application Example 1

[0155] This application example provides a continuous production method for trifluoroacetic acid. The continuous production method uses the integrated photo-oxidation and hydrolysis reaction apparatus described in Example 1, and the reaction steps are as follows:

[0156] First, deionized water is injected into the reboiler. The hot water in the reboiler jacket is set to 30℃, and the chilled brine at the top of the column is set to -10℃. The reactor pressure is 0.15MPa. The circulating pump is turned on to spray deionized water. The total spraying rate of the water-containing circulating material is about 50kg / h. Then, preheated and mixed gaseous raw materials of R123, oxygen and chlorine are introduced into the reaction device. The molar ratio of R123, oxygen and chlorine is 1:0.8:0.04, and the feed rates are 20kg / h, 3.35kg / h and 0.38kg / h, respectively.

[0157] With the LED light source turned on and the power set to 120W, photo-oxidation to produce trifluoroacetyl chloride and hydrolysis to produce trifluoroacetic acid occur simultaneously within the device. A small portion of unreacted R123 and some trifluoroacetyl chloride are refluxed and continue to undergo photo-oxidation and hydrolysis reactions, respectively, thus achieving efficient photo-oxidation of R123 and complete hydrolysis of TFAC.

[0158] After the system stabilized, the rates of water replenishment and bottom draining remained essentially consistent, approximately 120 kg / h, while the bottom liquid level remained stable. The crude trifluoroacetic acid discharged from the bottom was then separated and purified to obtain a qualified product.

[0159] After 2 hours of reaction, the composition of the gaseous product stream and the composition of the liquid material in the reactor bottom were analyzed based on the reactor outlet sampling to determine the conversion rate and selectivity of R123 photooxidation and the conversion rate and selectivity of TFAC.

[0160] The analysis and calculation results are as follows: the conversion rate of R123 photo-oxidation at the reactor outlet is 98.7%, the selectivity of TFAC is 99.5%, the selectivity of R113a is 0.5%, and the yield of TFAC is 98.2%. In the integrated unit, the hydrolysis conversion rate of TFAC is 98.9%, the selectivity of TFA is 100%, and the yield of TFA reaches 98.9%.

[0161] Application Example 2

[0162] This application example provides a continuous production method for trifluoroacetic acid. The only difference from Application Example 1 is that the reaction is carried out in the integrated photo-oxidation and hydrolysis reaction apparatus (375nm LED light source) provided in Example 2. The other steps are the same as in Application Example 1.

[0163] Application Example 3

[0164] This application example provides a continuous production method for trifluoroacetic acid. The only difference from application example 1 is that the reaction is carried out in the integrated photo-oxidation and hydrolysis reaction apparatus (400nm LED light source) provided in example 3. The other steps are the same as in application example 1.

[0165] Application Example 4

[0166] This application example provides a continuous production method for trifluoroacetic acid. The only difference from application example 1 is that the reaction is carried out in the integrated photo-oxidation and hydrolysis reaction apparatus (450nm LED light source) provided in example 4. The other steps are the same as in application example 1.

[0167] Application Example 5

[0168] This application example provides a continuous production method for trifluoroacetic acid. The only difference from application example 1 is that the reaction is carried out in the integrated photo-oxidation and hydrolysis reaction apparatus (475 nm LED light source) provided in example 5. The other steps are the same as in application example 1.

[0169] Application Example 6

[0170] This application example provides a continuous production method for trifluoroacetic acid. The only difference from Application Example 1 is that the reaction is carried out in the integrated photo-oxidation and hydrolysis reaction apparatus (490 nm LED light source) provided in Example 6. The other steps are the same as in Application Example 1.

[0171] The analysis and calculation results of the above application examples 1 to 6 are shown in Table 1 below:

[0172] Table 1

[0173]

[0174] Application Example 7

[0175] This application example provides a continuous production method for trifluoroacetic acid, which differs from Application Example 1 only in that the LED light source power is set to 30 W, while the other steps are the same as in Application Example 1.

[0176] Application Example 8

[0177] This application example provides a continuous production method for trifluoroacetic acid, which differs from Application Example 1 only in that the LED light source power is set to 60 W, while the other steps are the same as in Application Example 1.

[0178] Application Example 9

[0179] This application example provides a continuous production method for trifluoroacetic acid, which differs from Application Example 1 only in that the LED light source power is set to 90 W, while the other steps are the same as in Application Example 1.

[0180] Application Example 10

[0181] This application example provides a continuous production method for trifluoroacetic acid, which differs from Application Example 1 only in that the LED light source power is set to 150W, while the other steps are the same as in Application Example 1.

[0182] The analysis and calculation results of Application Example 1 and Application Examples 7-10 are shown in Table 2 below:

[0183] Table 2

[0184]

[0185] Application Example 11

[0186] This application example provides a continuous production method for trifluoroacetic acid. The only difference from application example 1 is that 10 of the 20 spray pipe discharge valves are opened at intervals from top to bottom, and the flow rate of each spray pipe is adjusted to 5 kg / h, so that the water-containing material is sprayed evenly. The other steps are the same as in application example 1.

[0187] Application Example 12

[0188] This application example provides a continuous production method for trifluoroacetic acid. The only difference from application example 1 is that 5 of the 20 spray pipe discharge valves are opened at intervals from top to bottom, and the flow rate of each spray pipe is adjusted to 10 kg / h to achieve uniform spraying of the water-containing material. The other steps are the same as in application example 1.

[0189] The analysis and calculation results of Application Example 1 and Application Examples 11-12 are shown in Table 3 below:

[0190] Table 3

[0191]

[0192]

[0193] Application Example 13

[0194] This application example provides a continuous production method for trifluoroacetic acid. The only difference from application example 1 is that the reaction is carried out in the integrated photo-oxidation and hydrolysis reaction apparatus (coarse-pore FEP transparent spray tube) provided in example 7. The sprayed material is mainly in droplet state. The other steps are the same as in application example 1.

[0195] Application Example 14

[0196] This application example provides a continuous production method for trifluoroacetic acid. The only difference from application example 1 is that the reaction is carried out in the integrated photo-oxidation and hydrolysis reaction apparatus (FEP transparent spray tube with finer pores) provided in example 8. The sprayed material is mainly in the form of aerosol. The other steps are the same as in application example 1.

[0197] The analysis and calculation results of Application Example 1 and Application Examples 13-14 are shown in Table 4 below:

[0198] Table 4

[0199]

[0200] Application Example 15

[0201] This application example provides a continuous production method for trifluoroacetic acid, which differs from Application Example 1 only in that the total spraying rate of the water-containing circulating material is approximately 20 kg / h, while the other steps are the same as in Application Example 1.

[0202] Application Example 16

[0203] This application example provides a continuous production method for trifluoroacetic acid, which differs from Application Example 1 only in that the total spraying rate of the water-containing circulating material is approximately 80 kg / h, while the other steps are the same as in Application Example 1.

[0204] The analysis and calculation results of Application Example 1 and Application Examples 15-16 are shown in Table 5 below:

[0205] Table 5

[0206]

[0207] Application Example 17

[0208] This application example provides a continuous production method for trifluoroacetic acid, which differs from Application Example 1 only in that the water replenishment rate and the bottom drain rate are 80 kg / h, while the other steps are the same as in Application Example 1.

[0209] Application Example 18

[0210] This application example provides a continuous production method for trifluoroacetic acid, which differs from Application Example 1 only in that the water replenishment rate and the bottom drain rate are 150 kg / h, while the other steps are the same as in Application Example 1.

[0211] The analysis and calculation results of Application Example 1 and Application Examples 17-18 are shown in Table 6 below:

[0212] Table 6

[0213]

[0214] Application Example 19

[0215] This application example provides a continuous production method for trifluoroacetic acid, which differs from Application Example 1 only in that R132a is used as the raw material for photoreaction, while the other steps are the same as in Application Example 1.

[0216] Application Example 20

[0217] This application example provides a continuous production method for trifluoroacetic acid, which differs from Application Example 1 only in that R122 is used as the raw material for photoreaction, while the other steps are the same as in Application Example 1.

[0218] The analysis and calculation results of Application Example 1 and Application Examples 19-20 are shown in Table 7 below:

[0219] Table 7

[0220]

[0221] Comparative Application Example 1

[0222] This comparative application example provides a continuous production method for trifluoroacetic acid. The only difference from Application Example 1 is that the reaction is carried out in the integrated photo-oxidation and hydrolysis reaction apparatus (the light source is a high-pressure mercury lamp) provided in Comparative Example 1, and the sprayed material is mainly in droplet form. The other steps are the same as in Application Example 1.

[0223] Comparative Application Example 2

[0224] This comparative application example provides a continuous production method for trifluoroacetic acid. The only difference from Application Example 1 is that the reaction is carried out in the integrated photo-oxidation and hydrolysis reaction apparatus (opaque PTFE perforated spray pipe) provided in Comparative Example 2, and the sprayed material is mainly in droplet form. The other steps are the same as in Application Example 1.

[0225] Comparative Application Example 3

[0226] This comparative application example provides a continuous production method for trifluoroacetic acid. The only difference from application example 1 is that the reaction is carried out in the integrated photo-oxidation and hydrolysis reaction device (with only a perforated spray pipe with the opening facing downward) provided in comparative example 3. The sprayed material is mainly in the state of droplets. The other steps are the same as in application example 1.

[0227] Comparative Application Example 4

[0228] This comparative application example provides a continuous production method for trifluoroacetic acid, which differs from Application Example 1 only in that the spray pipe is not turned on; the other steps are the same as in Application Example 1.

[0229] Comparative Application Example 5

[0230] This comparative application example provides a continuous production method for trifluoroacetic acid, which differs from Application Example 1 only in that it uses the photoreaction-hydrolysis system provided in Comparative Example 4 (a conventional hydrolysis tower is connected to the outside of the device so that the obtained product trifluoroacetyl chloride is transported from the gas outlet to the external first-stage hydrolysis tower for hydrolysis), and the other steps are the same as in Application Example 1.

[0231] The analysis and calculation results of the above application example 1 and the comparative application example 1 are shown in Table 8 below:

[0232] Table 8

[0233]

[0234] As shown in Table 8, Comparative Example 1 illustrates that using a high-pressure mercury lamp leads to a decrease in the conversion rate of R123 and the selectivity of TFAC. This is mainly attributed to the fact that most of the power of the high-pressure mercury lamp is exothermic, with only a small portion providing the light required for the reaction, thus affecting the efficiency of the photoreaction. Furthermore, the lamp contains short-wavelength ultraviolet light, which easily causes side reactions, resulting in a lower conversion rate of R123 and a higher selectivity for byproducts.

[0235] Comparative example 2 illustrates that using opaque PTFE as the spray tube leads to a decrease in R123 conversion. This is mainly attributed to the fact that opaque PTFE blocks some of the light emission and distribution, resulting in a reduction in the effective photoreaction area within the reactor, thus reducing photoreaction efficiency and consequently decreasing R123 conversion.

[0236] Comparative example 3 illustrates that using a spray pipe with only downward-facing openings will cause the water-containing circulating material to be sprayed only downwards, which is not conducive to the uniform distribution of water in the device, affecting the TFAC hydrolysis reaction and the rapid absorption of hydrogen chloride, and thus affecting the R123 photo-oxidation reaction, resulting in a decrease in the R123 conversion rate.

[0237] Comparative example 4 illustrates that without the spray pipes in operation, the lack of reverse contact reaction between the water-containing circulating material and the photo-oxidation product fluorinated acyl chloride, and the hydrolysis reaction relying solely on the water-containing material in the reactor bottom and a small amount of gaseous water in the system, leads to a low TFAC hydrolysis conversion rate. This, in turn, affects the coupled photo-oxidation and hydrolysis reaction, hindering the photo-oxidation reaction and resulting in a decrease in the R123 conversion rate.

[0238] Comparative Example 5 illustrates that without using an integrated device for the coupled photo-oxidation and hydrolysis reaction, the lack of hydrolysis in the reactor to consume fluorinated acyl chloride and absorb hydrogen chloride affects the photo-oxidation reaction, resulting in a significant decrease in the conversion rate of R123. The obtained product, trifluoroacetyl chloride, is transported from the outlet to an external primary hydrolysis tower. Since conventional hydrolysis towers only have spray heads at the top and do not have multi-stage spray pipes, and the concentration of fluorinated acyl chloride is high, it is difficult for the primary hydrolysis tower to achieve complete hydrolysis of the fluorinated acyl chloride, resulting in a low conversion rate of fluorinated acyl chloride and a correspondingly low yield of fluorinated acid.

[0239] The present invention uses a multi-stage spray pipe with a condenser at the top. After the fluorinated acyl chloride is generated in situ by the photo-oxidation reaction, the low concentration of fluorinated acyl chloride comes into reverse contact with the spray mist containing water, which can quickly and fully undergo a hydrolysis reaction.

[0240] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A photooxidation and hydrolysis integrated reaction device, characterized in that, The integrated photo-oxidation and hydrolysis reaction device includes a reaction tower, a light source system, and a spray circulation system; The light source system includes several LED light sources, which are interlaced and parallel to each other on both sides of the inner wall of the reaction tower, dividing the interior space of the reaction tower into a continuous serpentine channel. The spray circulation system includes a circulation pump and several perforated transparent spray pipes, with each perforated transparent spray pipe positioned above one of the LED light sources and on the same side of the inner wall of the reaction tower.

2. The integrated photo-oxidative and hydrolytic reaction device according to claim 1, wherein, Each of the LED light sources includes a glass sleeve and a light source rod disposed in the inner cavity of the glass sleeve. The light source rod includes a heat-conducting rod and a plurality of LED beads; wherein the LED beads are fixedly connected to the outside of the heat-conducting rod. Preferably, each of the LED light sources further includes a sealing connector; Preferably, the power of each LED light source is independently 30-180W, more preferably 40-170W; Preferably, the emission wavelength of each LED light source is independently 200-500 nm, and more preferably 300-490 nm; Preferably, the light source system includes 10 to 60 LED light sources; Preferably, the distance between each adjacent LED light source is 15-65cm, and more preferably 20-60cm; Preferably, the length of the glass sleeve is 55-100% of the inner diameter of the reaction tower body, and more preferably 60-95%.

3. The integrated photo-oxidative and hydrolytic reaction device according to claim 1, wherein The spray circulation system also includes a circulation pipeline located outside the reaction tower, which is used to connect the circulation pump and several perforated transparent spray pipes. Furthermore, the circulating pump is connected to the liquid outlet on the side of the reaction tower. The spray circulation system first pumps the water-containing material in the bottom of the reaction tower through the circulating pump and the circulating pipeline into each perforated transparent spray pipe for spraying the liquid phase water-containing material and forming a droplet mist. Preferably, the perforated transparent spray pipe is a spray pipe with holes on all four sides; Preferably, the inner diameter of the perforated transparent spray pipe is 3–20 mm; Preferably, the hole diameter of the opening of the perforated transparent shower pipe is 0.2-0.6mm, and the distribution density of the opening is 5-20 / cm 2 .

4. The integrated photo-oxidative and hydrolytic reaction apparatus according to claim 1, wherein The material of the perforated transparent spray pipe is selected from any one or a combination of at least two of PFA, FEP, PVF, ETFE, PCTFE, ECTFE or Teflon AF, preferably PFA and / or FEP; Preferably, the water at the bottom of the reaction tower is selected from any one or a combination of at least two of deionized water, distilled water or softened water, with deionized water being the preferred choice. Preferably, the perforated transparent spray pipes are evenly distributed above the light source system on the same side of the reaction tower body, and the second and lower groups of perforated transparent spray pipes from top to bottom are located in the middle of two adjacent LED light sources.

5. The integrated photooxidation and hydrolysis reactor of claim 1, wherein, The reaction tower has a cylindrical shape. Preferably, the height of the reaction tower is ≥10m; Preferably, the material of the reaction tower is selected from either corrosion-resistant metal lining polytetrafluoroethylene or enamel.

6. The integrated photooxidation and hydrolysis reactor of claim 1, wherein, The reaction tower includes a gaseous feed inlet, a gas outlet, a bottom drain outlet, and a water makeup inlet; The gaseous feed inlet is located on one side of the lower part of the reaction tower and above the liquid level in the bottom of the reaction tower; the gas outlet is located at the top of the reaction tower; the bottom drain outlet is located at the bottom of the reaction tower; and the water inlet is located on the other side of the lower part of the reaction tower. Preferably, a condensation system is provided at the top of the reaction tower, the condensation system including: a condenser, a cold material inlet and a cold material outlet; Preferably, the condenser is made of any one of silicon carbide, graphite, or enamel. Preferably, the reactor vessel is equipped with a heating system, which includes a heating jacket, a hot material inlet, and a hot material outlet, and the heating jacket covers the outside of the reactor vessel.

7. The application of the integrated photo-oxidation and hydrolysis reaction apparatus according to any one of claims 1 to 6 in the preparation of fluorinated acyl chloride by photo-oxidation reaction and the preparation of fluorinated acid by hydrolysis reaction.

8. Use according to claim 7, characterized in that, The fluorinated acyl chloride includes any one or a combination of at least two of trifluoroacetyl chloride, difluoroacetyl chloride, or difluorochloroacetyl chloride. The fluorinated acid includes any one or a combination of at least two of trifluoroacetic acid, difluoroacetic acid, or difluorochloroacetic acid.

9. A continuous process for the production of a fluoroacid, characterized in that, The continuous production method of the fluorinated acid is carried out using the integrated photo-oxidation and hydrolysis reactor as described in any one of claims 1 to 6, and specifically includes the following steps: A chlorofluorocarbon, oxygen, and chlorine are introduced into the reaction tower. Under the illumination of the LED light source, chlorine acts as a photoinitiator, causing the chlorofluorocarbon and oxygen to undergo a photo-oxidation reaction to obtain fluorinated acyl chloride. Simultaneously, a liquid-phase aqueous material is sprayed into the reaction tower through the perforated transparent spray pipe, causing the liquid-phase aqueous material to form droplets that come into countercurrent contact with the fluorinated acyl chloride to undergo a hydrolysis reaction, yielding crude fluorinated acid. After discharge, the crude product is separated and purified to obtain the fluorinated acid product.

10. The method of claim 9, wherein the fluorinated acid is produced continuously. The chlorofluorocarbons include any one or a combination of at least two of CF3CHCl2, CHF2CHCl2 or CClF2CHCl2; Preferably, the molar ratio of the chlorofluorocarbon, oxygen, and chlorine is 1:(0.5-1.5):(0.05-0.15), more preferably 1:(0.6-1.4):(0.06-0.14); Preferably, the temperature of the photo-oxidation reaction is 10–100°C, more preferably 20–90°C; the pressure of the photo-oxidation reaction is 0–0.35 MPa, more preferably 0.05–0.30 MPa. Preferably, the total spraying rate of the liquid phase water-containing material is 10-110 kg / h, and more preferably 20-100 kg / h; Preferably, during the hydrolysis reaction, water needs to be added to the bottom of the reaction tower while the crude fluoride product is discharged from the bottom outlet, and the inflow and outflow of the two are basically balanced. Preferably, the water replenishment rate is 50–180 kg / h, more preferably 80–150 kg / h; Preferably, the rate of discharge of the crude fluoride product is 50-180 kg / h, and more preferably 80-150 kg / h.

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