Treatment system and process for fluorine-containing gas

Abstract

The invention discloses a treatment system and process for fluorine-containing gas. The treatment system comprises a reaction unit, the reaction unit comprises at least two reactors which are connected in series to provide a space for catalytic decomposition and chemical adsorption of fluorine-containing organic matters, and the multiple reactors are vertically arranged; the gas inlet unit is used for selectively conveying fluorine-containing gas and hydrogen chloride to the reactor; the discharging unit is used for receiving the metal fluoride discharged from the reactor at the lowermost end; the feeding unit is used for conveying a catalyst to the reactor at the uppermost end; and the tail gas treatment unit is used for receiving gas discharged from the reactor. According to the technical scheme, the requirement that the catalyst is frequently replaced during continuous reaction is met, and on the basis that fluorine-containing organic matter in gas is removed through catalytic decomposition, chemical adsorption is further carried out, and a fluoride salt product with a high additional value is formed.

Description

Technical Field

[0001] This invention relates to the field of fluorine-containing gas treatment technology, and more specifically to a treatment system and process for fluorine-containing gases. Background Technology

[0002] With the development of fluorochemicals, large amounts of hydrogen chloride gas containing organic fluorine are generated in fluorine-containing organic compound production plants. Taking fluorine-based refrigerant production plants as an example, the main components of the large amount of hydrogen chloride gas produced as a byproduct are hydrogen chloride (>90%) and organic fluorine and other substances.

[0003] Regarding this byproduct hydrogen chloride gas, on the one hand, if it is not rationally utilized as a resource, it will eventually generate a large amount of fluorine-containing hazardous waste hydrochloric acid, which is not only difficult to treat effectively but also poses a significant threat to the environment. On the other hand, the hydrogen chloride itself contained in the byproduct gas can be used as a reactant to prepare other high-value basic chemical raw materials, bringing additional economic benefits to production. Therefore, in order to utilize this byproduct hydrogen chloride gas, it is first necessary to treat it, namely, the treatment of fluorine-containing organic compounds and the purification of hydrogen chloride.

[0004] Currently, the main treatment process for treating fluorinated organic compounds and purifying hydrogen chloride involves water absorption to generate hydrochloric acid and water-insoluble organic fluorine compounds. After the organic fluorine compounds are recovered, they are incinerated in an incinerator. The incineration exhaust gas is then further treated with water and alkali before being discharged.

[0005] The current treatment process has the following drawbacks: First, the existing process does not completely remove organic fluorine, resulting in a certain amount of organic fluorine remaining in the generated hydrochloric acid, which limits the comprehensive utilization of hydrogen chloride in the subsequent process; Second, the cost of defluorinating fluorine-containing hydrochloric acid is as high as 300-600 yuan per ton of hydrochloric acid, which is too high for enterprises to bear; Third, the current process generates a large amount of fluorine-containing wastewater when incinerating the tail gas, resulting in poor environmental benefits; Fourth, the current process only recovers hydrogen chloride and does not recover fluorine-containing organic compounds.

[0006] To address the current challenges in defluorination of fluorinated hydrogen chloride in the fluorochemical industry, Sinopec Catalyst Co., Ltd., Northwest University for Nationalities, and Central South University have jointly developed a catalyst for the catalytic decomposition of fluorinated organic compounds from fluorinated hydrogen chloride. The catalyst's key features are: under high temperature and hydrogen chloride conditions, the fluorinated organic compounds in hydrogen chloride are catalytically decomposed into hydrogen fluoride, CO, CO2, and water. The decomposed hydrogen fluoride further reacts with the active ingredients in the catalyst to form solid fluorides, which are then immobilized on the catalyst. In other words, the defluorination reaction involving this catalyst allows for simultaneous catalytic decomposition and chemical adsorption of fluorinated organic compounds. Extensive experimental verification has shown that this catalyst effectively solves the problem of defluorination of fluorinated hydrogen chloride, and the resulting solid fluorides can be recycled. Therefore, it can not only treat fluorinated organic compounds and purify hydrogen chloride but also prepare metal fluorides.

[0007] However, the method of defluorinating fluorinated hydrogen chloride using the aforementioned catalytic decomposition catalyst is a first in the fluorochemical industry, and no corresponding processing system or process existed previously. Furthermore, as the catalyst gradually transforms into solid fluoride, the catalytic decomposition also loses its activity. At this point, it is necessary to continuously remove the deactivated catalyst and add fresh catalyst to ensure uninterrupted reaction and achieve continuous production while maintaining the defluorination effect. Therefore, this process not only requires the continuous removal and replenishment of catalyst but also ensures uninterrupted continuous reaction. Currently, equipment capable of continuous reaction is relatively common in the fluorochemical industry, but a processing system suitable for processes requiring frequent catalyst replacement and capable of replacing the catalyst while conducting continuous reaction has not yet been developed. Summary of the Invention

[0008] In order to solve the above-mentioned technical problems, the present invention provides a treatment system and process for fluorine-containing gases to meet the needs of frequent catalyst replacement during continuous reaction. Furthermore, using this treatment system, fluorine-containing organic compounds in the gas can be removed by catalytic decomposition and then further chemically adsorbed to form fluoride salt products with high added value.

[0009] To achieve the above objectives, a first aspect of the present invention provides a system for treating fluorine-containing gases, comprising: A reaction unit comprising at least two reactors connected in series to provide space for the catalytic decomposition and chemisorption of fluorinated organic compounds, wherein a plurality of said reactors are arranged vertically. An air intake unit, comprising an air intake pipe and a valve body disposed between the air intake unit and the reaction unit, for selectively supplying fluorine-containing gas and hydrogen chloride to the reactor; The unloading unit includes an unloading pipeline and a valve body disposed between the unloading unit and the reaction unit, for receiving metal fluoride discharged from the reactor at the lowest end; The feeding unit includes a feeding pipeline and a valve body disposed between the feeding unit and the reaction unit, for feeding catalyst to the uppermost reactor; An exhaust gas treatment unit, comprising an exhaust pipe and a valve body disposed between the exhaust gas treatment unit and the reaction unit, for receiving gas discharged from the reactor.

[0010] In some embodiments, the reactor includes a conical sieve plate disposed in an upper and lower part of the reactor, the upper conical sieve plate being connected to the feed inlet of the reactor and the lower conical sieve plate being connected to the discharge outlet of the reactor.

[0011] In some embodiments, the plurality of reactors are one or more of a fixed bed, a boiling bed, and a fluidized bed, or the plurality of reactors are a moving bed.

[0012] In some embodiments, the reaction unit further includes a first gas supply line, a first end of which is connected to the outlet end of the gas inlet line, and a second end of which is connected to the gas inlets of the plurality of reactors.

[0013] In some embodiments, the reaction unit further includes a second gas supply line, which is sequentially connected to two adjacent reactors.

[0014] In some embodiments, the reaction unit further includes a maintenance pipeline, which includes the first gas supply pipeline and the second gas supply pipeline.

[0015] In some embodiments, the reaction unit further includes a gas sampling point, which is provided at the gas outlet of the reactor.

[0016] In some embodiments, the intake unit further includes a heater disposed on the intake manifold.

[0017] In some embodiments, the intake unit further includes a heat exchanger disposed between the heater and the inlet end of the intake pipe, the heat exchanger being disposed on both the intake pipe and the exhaust pipe.

[0018] In some embodiments, the air intake unit further includes a fluorine-containing gas intake pipe, an inert gas intake pipe, and a hydrogen chloride intake pipe, wherein the fluorine-containing gas intake pipe, the inert gas intake pipe, and the hydrogen chloride intake pipe are all connected to the inlet end of the air intake pipe.

[0019] In some embodiments, the feeding unit further includes a feeding hopper, a feeding bin, and a feeding bin disposed on the feeding pipeline. The feeding hopper is disposed at the inlet end of the feeding pipeline, the feeding bin is disposed between the inlet end and the outlet end of the feeding pipeline, and the feeding bin is disposed at the outlet end of the feeding pipeline and connected to the feed inlet of the uppermost reactor.

[0020] In some embodiments, the feeding unit further includes a second circulation pipeline, and the unloading unit further includes a first circulation pipeline and a recovery hopper connected to the outlet end of the unloading pipeline. A first end of the first circulation pipeline is connected to the recovery hopper and a second end is connected to the feeding pipeline, and a first end of the second circulation pipeline is connected to the feeding hopper and a second end is connected to the unloading pipeline, so as to realize the circulation of purging gas between the unloading unit and the feeding unit.

[0021] In some embodiments, the exhaust gas treatment unit further includes a gas exhaust pipe and a first inert gas exhaust pipe, both of which are connected to the outlet end of the exhaust pipe.

[0022] A second aspect of the present invention provides a process for treating fluorine-containing gases, the process being used in the aforementioned treatment system.

[0023] In some implementations, the following are included: 1) After heating the inert gas, it is introduced into the reactor through the gas inlet pipe until the reactor reaches the set reaction temperature; 2) Fluorine-containing gas and hydrogen chloride are introduced into the reactor through the inlet pipe, so that the fluorine-containing organic matter in the fluorine-containing gas is catalytically decomposed by the catalyst and further chemically adsorbed with the catalyst to generate gas and metal fluorides; 3) When the catalyst in the reactor is chemisorbed to saturation, disconnect the connection between the reactor and the inlet pipe and the upper reactor, discharge the metal fluoride from the discharge pipe, and then fill the catalyst from top to bottom into the lower reactor through the feed pipe. After filling, connect the reactor to the inlet pipe and the upper reactor.

[0024] In some implementations, the total duration of step 3) is set to 2 to 3 hours.

[0025] In some implementations, the following are included: 1) After heating the inert gas, it is introduced into the reactor through the gas inlet pipe until the reactor reaches the set reaction temperature; 2) Fluorine-containing gas and hydrogen chloride are introduced into the reactor through the inlet pipe, so that the fluorine-containing organic matter in the fluorine-containing gas is catalytically decomposed by the catalyst and further chemically adsorbed with the catalyst to generate gas and metal fluorides; The gas enters the exhaust pipe, and at the same time, the metal fluoride enters the unloading pipe. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a process diagram of one embodiment of the processing system disclosed in this invention.

[0028] Explanation of reference numerals in the attached figures 100. Inlet unit; 110. Inlet pipeline; 111. Fluorine-containing gas inlet pipeline; 112. Inert gas inlet pipeline; 113. Hydrogen chloride inlet pipeline; 120. Heater; 130. Heat exchanger; 200. Reaction unit; 210. First gas delivery pipeline; 220. Second gas delivery pipeline; 230. Reactor; 231. Conical sieve plate; 300. Discharge unit; 310. Discharge pipeline; 320. 330. First circulation pipeline; 400. Recycling hopper; 410. Feeding unit; 420. Feeding pipeline; 430. Second circulation pipeline; 440. Feeding hopper; 450. Feeding hopper; 500. Exhaust gas treatment unit; 510. Exhaust pipeline; 511. Gas exhaust pipeline; 512. First inert gas exhaust pipeline; 513. Second inert gas exhaust pipeline; 600. Gas sampling point. Detailed Implementation

[0029] While the background section describes the inventors' preliminary experiments and explorations related to this invention, it should be understood that these descriptions are merely for the sake of fluency and to facilitate a better understanding of the technical problems and solutions of this invention by those skilled in the art. Therefore, the inventors' experiments and discoveries described in the background section should also be considered contributions to this invention and should not be construed as being included in the prior art simply because they are described in the background section.

[0030] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0031] To address the problem that current fluorochemical processing systems cannot frequently replace catalysts and can replace catalysts simultaneously with continuous reactions, the first aspect of this invention provides a processing system for fluorine-containing gases, comprising: The reaction unit 200 includes at least two reactors 230 connected in series to provide space for the catalytic decomposition and chemical adsorption of fluorinated organic compounds, and the multiple reactors 230 are arranged vertically. The air intake unit 100 includes an air intake pipe 110 and a valve body disposed between the air intake unit 100 and the reaction unit 200, for selectively supplying fluorine-containing gas and hydrogen chloride to the reactor 230. The unloading unit 300 includes an unloading pipeline 310 and a valve body disposed between the unloading unit 300 and the reaction unit 200, for receiving metal fluorides discharged from the reactor 230 at the lowest end. The feeding unit 400 includes a feeding pipe 410 and a valve body disposed between the feeding unit 400 and the reaction unit 200, for feeding the catalyst to the uppermost reactor 230. The exhaust gas treatment unit 500 includes an exhaust pipe 510 and a valve body disposed between the exhaust gas treatment unit 500 and the reaction unit 200 for receiving gas discharged from the reactor 230.

[0032] Among them, such as Figure 1 As shown, the fluorine-containing gas treatment system may include a reaction unit 200, an inlet unit 100 and a feed unit 400 disposed upstream of the reaction unit 200, a discharge unit 300 and a tail gas treatment unit 500 disposed downstream of the reaction unit 200.

[0033] The treatment process for fluorine-containing gases is the defluorination process, which involves the catalytic decomposition and chemical adsorption of fluorine-containing organic compounds. This process takes place in reactor 230, which is included in reaction unit 200. Reactor 230 is equipped with an inlet, an outlet, a feed inlet, and a discharge outlet. To ensure the defluorination effect of the fluorine-containing gases, at least two reactors 230 are provided and connected in series. It should be noted that reaction unit 200 here includes at least two reactors 230 connected in series, including two cases: all reactors 230 are connected in series, with at least two reactors 230; or some reactors 230 are connected in series and some in parallel, with at least two reactors 230 connected in series. The number of reactors 230 is preferably set to 5 to 8.

[0034] Multiple reactors 230 are arranged vertically. In adjacent reactors 230, the outlet of the lower reactor 230 is connected in series with the inlet of the upper reactor 230, and the inlet of the lower reactor 230 is connected in series with the outlet of the upper reactor 230. A valve is installed on the pipeline connecting the outlets and inlets of adjacent reactors 230 to control the gas flow between them and to enable the series-parallel connection of the reactors 230. This valve is preferably a two-position valve and / or a ball valve. To ensure effective defluorination, the reactors 230 are preferably connected in series. Actual sampling and testing showed that even when some reactors 230 are connected in parallel, the defluorination treatment standard can still be met by controlling the flow rate of the fluorinated gas entering the reactors 230, while simultaneously improving production efficiency. In addition, to ensure that when reactors 230 are connected in parallel, high-temperature gas bypasses the lower reactor 230 and directly enters the upper reactor 230, a pressure regulating valve (not shown in the figure) can be added to the pipeline connecting the outlet and inlet of adjacent reactors 230.

[0035] In some other embodiments, the valves between the inlets and outlets of adjacent reactors 230 can also be replaced by flexible hoses or straight pipe sections. During the reaction, the valve at the outlet of the lowest reactor 230 is partially opened, allowing the catalyst to fall from top to bottom through multiple reactors 230 and enter the discharge pipe 310. Simultaneously, the fluorine-containing gas can flow from bottom to top through multiple reactors 230 and finally enter the exhaust pipe 510. In this way, the multiple reactors 230 in the reaction unit 200 can be considered as a whole, achieving the same effect as a moving bed reactor.

[0036] Additionally, it should be noted that when purifying hydrogen chloride containing organofluorine, when all reactors 230 are connected in parallel, a single reactor 230 can achieve defluorination of the fluorine-containing gas. Furthermore, when reactor 230 is a moving bed, qualified metal fluoride products can be obtained. When at least two reactors 230 are connected in series, defluorination of the fluorine-containing gas and obtaining qualified hydrogen chloride and metal fluoride products can be achieved simultaneously.

[0037] The outlet end of the air inlet pipe 110 of the air inlet unit 100 can be connected to the air inlet of each reactor 230 in the reaction unit 200.

[0038] Since the fluorine-containing gas needs to be defluorinated sequentially through each reactor 230, the outlet end of the inlet pipe 110 is configured to selectively connect directly to and supply the fluorine-containing gas to the reactor 230 during the defluorination process. This reactor 230 is designated as the first stage, or all of the multiple reactors 230 connected in parallel are first stages. Because the catalyst in the reactor 230 needs frequent replacement, the reactor 230, as the first stage, may change during catalyst replacement. Therefore, the inlet pipe 110 needs to be able to selectively supply the fluorine-containing gas to each reactor 230.

[0039] The above operation can be achieved by installing valves on the pipeline between the outlet end of the inlet pipe 110 and the inlet of each reactor 230. During the defluorination process, the valve at the inlet of the first-stage reactor 230 is in the open state, while the valves at the inlets of the other reactors 230 are in the closed state. The valve is preferably a two-position valve and / or a ball valve.

[0040] As can be seen from the above, since the reactors 230 are connected in sequence, and the outlet end of the inlet pipe 110 can be connected to the inlet of each reactor 230 in the reaction unit 200 respectively, even if one or more reactors 230 are disconnected from the inlet pipe 110, the remaining reactors 230 can be connected in series and parallel by controlling the opening and closing of the valve body, which means that the need to replace the catalyst while continuously reacting is realized.

[0041] The inlet end of the unloading pipe 310 of the unloading unit 300 can be connected to the outlet of the reactor 230 at the bottom.

[0042] Because multiple reactors 230 are arranged vertically and the inlets and outlets of adjacent reactors 230 are connected in series, the catalyst can fall by gravity during unloading and be discharged uniformly from the outlet of the lowest reactor 230. During defluorination, the inlet of the unloading pipeline 310 can be connected to the outlet of the lowest reactor 230 to receive metal fluorides, i.e., the catalyst deactivated after chemical adsorption. This achieves two advantages: firstly, it allows for the recovery of deactivated catalyst from each reactor 230 using a single pipeline, reducing production costs; secondly, it facilitates the redistribution of the catalyst within each reactor 230 during its descent, ensuring a complete reaction.

[0043] The above operation can be achieved by installing a valve body on the discharge pipeline 310. This valve body is preferably a two-position valve and a discharge valve. The two-position valve can be installed near the discharge port of the reactor 230, and the discharge valve can be installed away from the discharge port of the reactor 230. Preferably, the two-position valve can be installed at the discharge port of the reactor 230, and the discharge valve is connected to the two-position valve.

[0044] The outlet end of the feed pipe 410 of the feed unit 400 can be connected to the feed port of the uppermost reactor 230.

[0045] After the bottom reactor 230 has finished unloading, the catalyst can be refilled into the reactor 230 through the feed pipe 410. Since multiple reactors 230 are arranged vertically and the inlets and outlets of adjacent reactors 230 are connected in series, the catalyst can fall under gravity. The feed pipe 410 can deliver catalyst to the top reactor 230, and the catalyst in the remaining reactors 230 falls sequentially into the reactors 230 below them until all reactors 230 are refilled with catalyst. This achieves the goal of refilling the catalyst into each reactor 230 using a single pipe, reducing production costs. Furthermore, it facilitates the redistribution of the catalyst within each reactor 230 during its descent, ensuring a complete reaction. The valve between the feed pipe 410 and the top reactor 230 is preferably a two-position valve.

[0046] The inlet end of the exhaust pipe 510 of the exhaust gas treatment unit 500 can be connected to the outlet of each reactor 230 in the reaction unit 200.

[0047] Since the fluorine-containing gas needs to be defluorinated by passing through each reactor 230 in sequence, the inlet end of the exhaust pipe 510 is configured to be directly connected to one or more of the reactors 230 during the defluorination process and to receive the discharged gas. The reactor 230 is configured as the last stage or the parallel reactors 230 are configured as the last stage at the same time.

[0048] The above operation can be achieved by installing a valve body on the exhaust pipe 510, preferably located on the exhaust pipe 510 near the outlet of the reactor 230. Specifically, during the defluorination process, the valve body at the outlet of the last stage reactor 230 is in the open state, while the valve bodies at the outlets of the remaining stages of reactor 230 are in the closed state. This valve body is preferably a ball valve.

[0049] The valve bodies in the above technical solutions can all be switched by integrated self-control valves to achieve fully automated control, eliminating the need for manual switching and ensuring high process safety.

[0050] The above technical solution provides a treatment system for fluorine-containing gases to meet the need for frequent catalyst replacement during continuous reactions. Furthermore, this treatment system can remove fluorine-containing organic compounds from the gas through catalytic decomposition and then further perform chemical adsorption to form fluoride salt products with high added value.

[0051] In some embodiments, reactor 230 includes a conical sieve plate 231 disposed in the upper and lower parts of reactor 230. The upper conical sieve plate 231 is connected to the feed inlet of reactor 230, and the lower conical sieve plate 231 is connected to the discharge outlet of reactor 230.

[0052] like Figure 1 As shown, the conical sieve plate 231 serves to perform gas-solid separation and facilitate catalyst replacement. Specifically, the conical sieve plate 231 can limit the catalyst inside the reactor 230, achieving separation of gas and catalyst. The sieve aperture size of the conical sieve plate 231 can be set smaller than the size of the catalyst particles to prevent catalyst particles from falling outside the conical sieve plate 231. Since catalyst passes through both the inlet and outlet of the reactor 230, conical sieve plates 231 are installed in both the upper and lower parts of the reactor 230. Furthermore, the arrangement of the upper and lower conical sieve plates 231 allows for the redistribution of fluorine-containing gas within each layer of conical sieve plates 231. This prevents gas from exhibiting flow deviation or channeling phenomena in the reactor 230, promoting more complete reaction of the fluorine-containing gas and ensuring the defluorination effect.

[0053] In some embodiments, the multiple reactors 230 are one or more of fixed beds, boiling beds, and fluidized beds, or the multiple reactors 230 are moving beds. The type of reactor 230 can be selected as a fixed bed, boiling bed, or fluidized bed according to the actual diameter of the reactor 230 required for the reaction, and multiple reactors 230 can be of the same type or a combination of multiple types. Alternatively, all multiple reactors 230 are moving beds, in which case all reactors 230 are connected in series.

[0054] In some embodiments, the reaction unit 200 further includes a first gas supply line 210, the first end of which is connected to the outlet end of the gas inlet line 110, and the second end of which is connected to the gas inlet of a plurality of reactors 230 respectively.

[0055] like Figure 1 As shown, the first gas supply line 210 can be configured as a pipeline between the outlet end of the inlet line 110 and the inlet of each reactor 230, and each first gas supply line 210 is equipped with a valve body. The first gas supply line 210 is used to transport fluorine-containing gas from the inlet unit 100 to the reaction unit 200, and to achieve a direct connection between the outlet end of the inlet line 110 and the inlet of each reactor 230, so that when a reactor 230 in the reaction unit 200 needs to replace the catalyst or needs maintenance, the connection with the reactor 230 can be switched in a timely manner. The valve body is preferably a two-position valve and / or a ball valve.

[0056] In some embodiments, the reaction unit 200 further includes a second gas supply line 220, which is sequentially connected to two adjacent reactors 230.

[0057] like Figure 1 As shown, the second gas supply line 220 can be configured as a pipeline connecting reactors 230 in series, used to transport fluorine-containing gas from the outlet of the previous reactor 230 to the inlet of the next reactor 230. A valve body can be installed on the second gas supply line 220 to control the transport of fluorine-containing gas between the reactors 230. The valve body is preferably a ball valve.

[0058] It should be noted that the first gas supply pipeline 210 and the second gas supply pipeline 220 can preferably be integrated as a single unit to simplify the structure and reduce production costs. Specifically, since the multiple reactors 230 in this scheme are arranged vertically, the first gas supply pipeline 210 can be designed to consist of a vertical main gas supply pipeline and multiple branch gas supply pipelines. The outlet of each reactor 230 is connected to a branch gas supply pipeline and then into the main gas supply pipeline, with the valve body installed on the branch gas supply pipeline. At the same time, the second gas supply pipeline 220 can be connected to the outlet of the reactor 230 and then into the main gas supply pipeline. In this way, the fluorine-containing gas discharged from the reactor 230 of the previous stage enters the main gas supply pipeline through the second gas supply pipeline 220, and then enters the branch gas supply pipeline of the next stage reactor 230, realizing the transportation of fluorine-containing gas between adjacent reactors 230. Furthermore, to prevent fluorine-containing gas from being discharged vertically upwards along the main gas pipeline without passing through the branch gas pipelines, a valve body is installed between the gas inlet and outlet of each reactor 230 at the point where they connect to the main gas pipeline. The valve body is preferably a ball valve. In some other embodiments, the first gas pipeline 210 and the second gas pipeline 220 can also be installed separately.

[0059] In some embodiments, the reaction unit 200 further includes maintenance lines, which include a first gas supply line 210 and a second gas supply line 220.

[0060] like Figure 1 As shown, when the treatment system is shut down for maintenance, the residual gas in the first gas supply line 210, the second gas supply line 220, and the reactor 230 of the reaction unit 200 needs to be purged to the tail gas treatment unit 500. This route is consistent with the transport route of the fluorine-containing gas in the reaction unit 200. Therefore, the maintenance pipelines include the first gas supply line 210 and the second gas supply line 220, and no additional pipelines are required. When the reactor 230 malfunctions and needs maintenance, the operation of replacing the catalyst in the reactor 230 can be referenced. After disconnecting the valve on the second gas supply line 220 connected to the reactor 230, maintenance can be performed separately. After maintenance, the valves on both sides can be opened and reconnected to the second gas supply line 220.

[0061] In some embodiments, the reaction unit 200 further includes a gas sampling point 600, which is provided at the gas outlet of the reactor 230.

[0062] like Figure 1 As shown, the gas sampling point 600 can be set on the second gas supply pipeline 220 connected to the gas outlet of the reactor 230. It is used to periodically detect the content of fluorinated organic compounds in the fluorinated gas. When the content of fluorinated organic compounds no longer changes, it can be determined that the catalyst in the reactor 230 has been saturated. Specifically, the gas sampling point 600 can consist of a valve body, a sampling tube, and a sampling bottle (not shown in the figure). The preferred location for the gas sampling point 600 on the second gas supply pipeline 220 is on the second gas supply pipeline 220 before the gas outlet of the reactor 230 connects to the first gas supply pipeline 210. This ensures that the sampled gas conditions are as consistent as possible with the actual gas conditions inside the reactor 230.

[0063] In some embodiments, the intake unit 100 further includes a heater 120 disposed on the intake duct 110.

[0064] like Figure 1 As shown, since the reaction temperature required by reactor 230 needs to be at a high temperature (300~500℃), the gas (including inert gas and fluorine-containing gas) needs to be heated before being introduced into reactor 230. The heating of the gas is achieved by heater 120. Heater 120 is preferably an electric heater.

[0065] In some embodiments, the intake unit 100 further includes a heat exchanger 130 disposed between the heater 120 and the inlet end of the intake pipe 110, and the heat exchanger 130 is disposed on both the intake pipe 110 and the exhaust pipe 510.

[0066] like Figure 1 As shown, the gas temperature at the outlet from reactor 230 to exhaust pipe 510 is relatively high and needs to be cooled before entering the subsequent system. As mentioned earlier, the gas needs to be heated before entering reactor 230. Therefore, to utilize this heat, a heat exchanger 130 can be installed on the inlet pipe 110. Both the inlet pipe 110 and exhaust pipe 510 are connected to the heat exchanger 130, enabling heat exchange between the gas entering reactor 230 and the gas exiting reactor 230. This not only achieves heat recovery and utilization but also significantly reduces the energy consumed by heater 120, effectively lowering production costs. The heat exchanger 130 is located between heater 120 and the inlet end of inlet pipe 110, allowing the gas to be heated to a certain temperature first by the heat exchanger 130. Then, the temperature of heater 120 can be adjusted according to actual conditions, achieving precise control of the gas temperature entering reactor 230.

[0067] In some embodiments, the air intake unit 100 further includes a fluorine-containing gas intake pipe 111, an inert gas intake pipe 112, and a hydrogen chloride intake pipe 113, all of which are connected to the inlet end of the air intake pipe 110.

[0068] like Figure 1 As shown, the fluorine-containing gas inlet pipeline 111 is used to introduce the fluorine-containing gas obtained from the preceding system into the processing system. Therefore, the inlet end of the inlet pipeline 110 is connected to the fluorine-containing gas inlet pipeline 111, and a two-position valve is installed on the fluorine-containing gas inlet pipeline 111. The preheating, purging, and pressure maintenance of the processing system all require the introduction of inert gas. Therefore, the inlet end of the inlet pipeline 110 is connected to the inert gas inlet pipeline 112, and a pressure regulating valve and a two-position valve are correspondingly installed on the inert gas inlet pipeline 112.

[0069] Since the defluorination reaction requires the presence of hydrogen chloride, a hydrogen chloride inlet pipeline 113 is also necessary. The inlet end of inlet pipeline 110 is connected to the hydrogen chloride inlet pipeline 113, which is equipped with a two-position valve. It should be noted that in actual production, most fluorine-containing gases also contain hydrogen chloride. Therefore, the two-position valve on the hydrogen chloride inlet pipeline 113 can be set to a normally closed state. When the fluorine-containing gas does not contain hydrogen chloride, the two-position valve on the hydrogen chloride inlet pipeline 113 is then opened.

[0070] In some embodiments, the feeding unit 400 further includes a feeding hopper 430, a feeding bin 440, and a plurality of feeding bins 450 disposed on the feeding pipeline 410. The feeding hopper 430 is disposed at the inlet end of the feeding pipeline 410, the feeding bin 440 is disposed between the inlet end and the outlet end of the feeding pipeline 410, and the feeding bin 450 is disposed at the outlet end of the feeding pipeline 410 and connected to the feed inlet of the uppermost reactor 230.

[0071] like Figure 1 As shown, the catalyst enters the feeding unit 400 from the outside through the feeding hopper 430. The outlet of the feeding hopper 430 is connected to the feeding pipeline 410. A discharge valve can be installed at the outlet to adjust the amount of catalyst fed. The catalyst is transported in the feeding pipeline 410 by pneumatic conveying. Compressed air or inert gas can be used for pneumatic conveying. Specifically, a first blower and a gas filter connected to the first blower are installed at the inlet of the feeding pipeline 410. A feeder is installed at the connection between the outlet of the feeding hopper 430 and the feeding pipeline 410. After filtration, the pneumatic gas is transported along the feeding pipeline 410 through the cooperation of the first blower and the feeder.

[0072] The feeding hopper 440 is located between the inlet and outlet ends of the feed pipe 410, preferably in the middle of the feed pipe 410. It receives and stores the catalyst delivered by the feeding hopper 430 and supplies the catalyst to the reaction unit 200. Specifically, both the inlet and outlet of the feeding hopper 440 are connected to the feed pipe 410. A discharge valve can be installed at the outlet to regulate the catalyst discharge rate. A feeder and a second fan connected to the feeder are installed at the connection between the outlet of the feeding hopper 440 and the feed pipe 410 to allow pneumatic gas to continue transporting the catalyst along the feed pipe 410. A dust collector can be installed at the top of the feeding hopper 440 to filter and remove catalyst dust from the hopper 440, preventing dust pollution of the environment.

[0073] The feed hopper 450 is located at the outlet end of the feed pipe 410. Since the outlet end of the feed pipe 410 is connected to the uppermost reactor 230, only one feed hopper 450 needs to be set at the feed inlet of the uppermost reactor 230. This can effectively reduce production costs. On the other hand, since the catalyst is stored in the feed hopper 440, when feeding the reactor 230, only the discharge valve and the second blower need to be opened, and there is no need to frequently feed the feed hopper 430, which simplifies the feeding process.

[0074] In some embodiments, the feeding unit 400 further includes a second circulation pipeline 420, and the unloading unit 300 further includes a first circulation pipeline 320 and a recovery hopper 330 connected to the outlet end of the unloading pipeline 310. The first end of the first circulation pipeline 320 is connected to the recovery hopper 330 and the second end is connected to the feeding pipeline 410. The first end of the second circulation pipeline 420 is connected to the feeding hopper 450 and the second end is connected to the unloading pipeline 310, so as to realize the circulation of pneumatic gas between the unloading unit 300 and the feeding unit 400.

[0075] like Figure 1 As shown, the catalyst is conveyed in both the unloading pipeline 310 and the feed pipeline 410 via pneumatic conveying. Connecting the unloading pipeline 310, the first circulation pipeline 320, the feed pipeline 410, and the second circulation pipeline 420 end-to-end allows the pneumatic gas to circulate between the unloading unit 300 and the feed unit 400. This improves the utilization rate of the pneumatic gas. Furthermore, the pneumatic gas is heated while conveying the high-temperature catalyst in the unloading pipeline 310. The heated pneumatic gas then enters the feed pipeline 410 via the first circulation pipeline 320, transferring heat to the catalyst falling from the feed hopper 440. This heat exchange between the catalyst and the deactivated catalyst facilitates the full reaction in the reactor 230.

[0076] Specifically, the discharge port of the lowest reactor 230 is equipped with a two-position valve and a discharge valve in sequence. A feeder is installed at the connection between the discharge port of the lowest reactor 230 and the discharge pipeline 310 to send the deactivated catalyst into the recovery silo 330 via the discharge pipeline 310. The discharge port of the recovery silo 330 is equipped with a discharge valve, and its upper end is connected to a first circulation pipeline 320. The second end of the first circulation pipeline 320 is preferably connected to the discharge port of the feeding silo 440 at the feed pipeline 410. Specifically, this position can be directly connected to the air inlet of the second blower, which can minimize the waste of heat from the blower gas and improve the heat exchange efficiency between the catalyst and the deactivated catalyst. The second end of the second circulation pipeline 420 can be connected to the input end of the discharge pipeline 310, specifically, it can be connected to the feeder at the input end.

[0077] Furthermore, an inert gas inlet pipe can be connected to the second circulation pipe 420 to replenish the inert gas in the circulation pipe and ensure smooth circulation. A pressure regulating valve can be installed on the inert gas inlet pipe to regulate and stabilize the pressure in the circulation pipe. A second inert gas exhaust pipe 513 can also be installed on the first circulation pipe 320 to refresh the inert gas in the circulation pipe in a timely manner.

[0078] In some embodiments, the exhaust gas treatment unit 500 further includes a gas exhaust pipe 511 and a first inert gas exhaust pipe 512, both of which are connected to the outlet end of the exhaust pipe 510.

[0079] like Figure 1 As shown, the gas discharged from reaction unit 200 is discharged through exhaust pipe 510. Gas exhaust pipe 511 is used to receive the defluorinated gas discharged from exhaust pipe 510, and a two-position valve is installed on gas exhaust pipe 511. A first inert gas exhaust pipe 512 is used to receive the inert gas discharged from exhaust pipe 510, and a two-position valve is installed on the first inert gas exhaust pipe 512. Gas exhaust pipe 511 and the first inert gas exhaust pipe 512 can be connected to an alkaline scrubbing tower and / or a water scrubbing tower to clean the gas.

[0080] A second aspect of the present invention provides a process for treating fluorine-containing gases, the process being carried out using the aforementioned treatment system.

[0081] In some implementations, the processing technology includes: 1) After heating the inert gas, it is introduced into the reactor 230 through the gas inlet pipe 110 until the reactor 230 reaches the set reaction temperature. 2) Fluorine-containing gas and hydrogen chloride are introduced into reactor 230 through inlet pipe 110, so that the fluorine-containing organic matter in the fluorine-containing gas is catalytically decomposed by the catalyst and further chemically adsorbed with the catalyst to generate gas and metal fluoride. 3) When the catalyst in reactor 230 is chemisorbed to saturation, disconnect the connection between reactor 230 and inlet pipe 110 and upper reactor 230. After the metal fluoride is discharged from unloading pipe 310, the catalyst is filled into reactor 230 from top to bottom through feed pipe 410. After filling, connect reactor 230 to inlet pipe 110 and upper reactor 230.

[0082] Among them, such as Figure 1 As shown, during the process of filling the catalyst from top to bottom into the reactor 230 at the bottom via the feed pipe 410, the opening sequence of the valves between the feed inlets and outlets of adjacent reactors is set to open sequentially from bottom to top. Level gauges are installed at the upper and lower ends of reactor 230 to detect the internal catalyst content and determine whether the catalyst filling is complete.

[0083] In this invention, the content of fluorine-containing organic compounds in the sample is measured at gas sampling point 600 to determine whether the catalyst needs to be replaced. Of course, different replacement intervals can also be set.

[0084] In some embodiments, the total duration of step 3) is set to 2 to 3 hours. This processing technology preferably achieves fully automated control through integrated self-regulating valve switching, thus ensuring high material replacement efficiency and maximizing the participation of each reactor 230 in the reaction during the processing.

[0085] In some implementations, the following are included: 1) After heating the inert gas, it is introduced into the reactor 230 through the gas inlet pipe 110 until the reactor 230 reaches the set reaction temperature. 2) Fluorine-containing gas and hydrogen chloride are introduced into reactor 230 through inlet pipe 110, so that the fluorine-containing organic matter in the fluorine-containing gas is catalytically decomposed by the catalyst and further chemically adsorbed with the catalyst to generate gas and metal fluoride. Gas enters the exhaust pipe 510, while metal fluoride enters the unloading pipe 310.

[0086] In this configuration, multiple reactors 230 are moving beds, connected in series. Alternatively, the valves between the inlets and outlets of adjacent reactors 230 can be replaced by flexible hoses or straight pipe sections. The multiple reactors 230 in the reaction unit 200 can be considered as a single unit, achieving the same effect as a moving bed reactor. During this process, the catalyst continuously enters the reactors 230 through the feed pipe 410.

[0087] The various embodiments of the present invention have now been described in detail. To avoid obscuring the concept of the invention, some details known in the art have not been described. Those skilled in the art will fully understand how to implement the technical solutions disclosed herein based on the above description.

[0088] While specific embodiments of the present invention have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of the invention. Those skilled in the art should understand that modifications can be made to the above embodiments or equivalent substitutions can be made to some technical features without departing from the scope and spirit of the invention. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any manner.

Claims

1. A system for the treatment of fluorine-containing gases, characterized in that, The application relates to a fluorine-containing organic matter catalytic decomposition and chemical adsorption device. The device comprises a reaction unit (200) comprising at least two reactors (230) connected in series to provide space for catalytic decomposition and chemical adsorption of fluorine-containing organic matter, and a plurality of reactors (230) arranged vertically. The device further comprises a gas inlet unit (100) comprising a gas inlet pipeline (110) and a valve body arranged between the gas inlet unit (100) and the reaction unit (200) to selectively deliver fluorine-containing gas and hydrogen chloride to the reactors (230). The device further comprises a discharge unit (300) comprising a discharge pipeline (310) and the valve body arranged between the discharge unit (300) and the reaction unit (200) to receive metal fluoride discharged from the lowermost reactor (230). The device further comprises a feed unit (400) comprising a feed pipeline (410) and the valve body arranged between the feed unit (400) and the reaction unit (200) to deliver catalyst to the uppermost reactor (230). The device further comprises a tail gas treatment unit (500) comprising an exhaust pipeline (510) and the valve body arranged between the tail gas treatment unit (500) and the reaction unit (200) to receive gas discharged from the reactors (230).

2. The processing system of claim 1, wherein, The reactors (230) comprise conical sieve plates (231) arranged at upper and lower portions in the reactors (230), the upper conical sieve plates (231) being connected to feed inlets of the reactors (230), and the lower conical sieve plates (231) being connected to discharge outlets of the reactors (230).

3. The processing system of claim 1, wherein, The reactors (230) are one or more of fixed bed, boiling bed and fluidized bed, or the reactors (230) are moving bed.

4. The processing system of claim 1, wherein, The reaction unit (200) further comprises a first gas delivery pipeline (210) having a first end connected to an outlet end of the gas inlet pipeline (110) and a second end connected to gas inlets of the reactors (230).

5. The processing system of claim 4, wherein, The reaction unit (200) further comprises a second gas delivery pipeline (220) connected to two adjacent reactors (230) in sequence.

6. The processing system of claim 5, wherein, The reaction unit (200) further comprises a maintenance pipeline comprising the first gas delivery pipeline (210) and the second gas delivery pipeline (220).

7. The processing system of claim 1, wherein The reaction unit (200) further comprises a gas sampling point (600) arranged at a gas outlet of the reactors (230).

8. The processing system of claim 1, wherein, The gas inlet unit (100) further comprises a heater (120) arranged on the gas inlet pipeline (110).

9. The processing system of claim 8, wherein, The air inlet unit (100) further comprises a heat exchanger (130) arranged between the heater (120) and the inlet end of the air inlet pipeline (110), and the heat exchanger (130) is arranged on both the air inlet pipeline (110) and the exhaust pipeline (510).

10. The processing system of claim 1, wherein, The air inlet unit (100) further comprises a fluorine-containing gas inlet pipeline (111), an inert gas inlet pipeline (112) and a hydrogen chloride inlet pipeline (113), and the fluorine-containing gas inlet pipeline (111), the inert gas inlet pipeline (112) and the hydrogen chloride inlet pipeline (113) are connected to the inlet end of the air inlet pipeline (110).

11. The processing system of claim 1, wherein, The feeding unit (400) further comprises a feeding hopper (430), a feeding bin (440) and a feeding bin (450) arranged on the feeding pipeline (410), the feeding hopper (430) is arranged at the inlet end of the feeding pipeline (410), the feeding bin (440) is arranged between the inlet end and the outlet end of the feeding pipeline (410), and the feeding bin (450) is arranged at the outlet end of the feeding pipeline (410) and connected to the feeding port of the uppermost reactor (230).

12. The processing system of claim 11, wherein, The feeding unit (400) further comprises a second circulating pipeline (420), and the discharging unit (300) further comprises a first circulating pipeline (320) and a recovery bin (330) connected to the outlet end of the discharging pipeline (310), the first end of the first circulating pipeline (320) is connected to the recovery bin (330) and the second end is connected to the feeding pipeline (410), and the first end of the second circulating pipeline (420) is connected to the feeding bin (450) and the second end is connected to the discharging pipeline (310), so as to realize the circulation of the purge gas between the discharging unit (300) and the feeding unit (400).

13. The processing system of claim 1, wherein, The exhaust treatment unit (500) further comprises a gas exhaust pipeline (511) and a first inert gas exhaust pipeline (512), and both the gas exhaust pipeline (511) and the first inert gas exhaust pipeline (512) are connected to the outlet end of the exhaust pipeline (510).

14. A process for the treatment of fluorine-containing gases, characterized in that, The processing process is completed by using the processing system of any one of claims 1-13.

15. The process of claim 14, wherein, It comprises: 1) After the inert gas is heated, it is introduced into the reactor (230) through the air inlet pipeline (110) until the inside of the reactor (230) reaches the set reaction temperature; 2) The fluorine-containing gas and hydrogen chloride are introduced into the reactor (230) through the air inlet pipeline (110), so that the fluorine-containing organic matter in the fluorine-containing gas is catalytically decomposed by the catalyst and further chemisorbed with the catalyst to generate gas and metal fluoride; 3) When the catalyst in the reactor (230) is saturated with chemical adsorption, disconnect the reactor (230) from the gas inlet pipeline (110) and the upper reactor (230), discharge the metal fluoride from the discharge pipeline (310), then fill the catalyst into the lowermost reactor (230) from top to bottom through the feed pipeline (410), and after filling is completed, connect the reactor (230) with the gas inlet pipeline (110) and the upper reactor (230).

16. The process of claim 15, wherein, The total duration of step 3) is set to 2-3 hours.

17. The process of claim 14, wherein, Comprising: 1) After warming the inert gas, pass it into the reactor (230) through the gas inlet pipeline (110) until the internal temperature of the reactor (230) reaches the set reaction temperature; 2) Pass the fluorine-containing gas and hydrogen chloride into the reactor (230) through the gas inlet pipeline (110), so that the fluorine-containing organic matter in the fluorine-containing gas is catalytically decomposed by the catalyst and further chemically adsorbed with the catalyst to generate gas and metal fluoride; The gas enters the exhaust pipeline (510), and at the same time, the metal fluoride enters the discharge pipeline (310).

Images