Device for preparing hydrogen fluoride by molecular identification complexation method and application thereof

Abstract

The invention discloses a device for preparing hydrogen fluoride by a molecular recognition complexing method and application thereof. The device comprises an integrated partition reactor, a dryer and a double-tower circulation type thermal decomposition system which are connected in sequence, the integrated partitioned reactor comprises a complexation reaction-in-situ filtering region and a cross-linking reaction region; a spiral propelling type stirrer and a filter are sequentially arranged in the complex reaction-in-situ filtering region from front to back; the filter is vertically arranged, and the filtering surface of the filter is perpendicular to the flow direction of materials propelled by the spiral propelling type stirrer; a discharge baffle with adjustable on-off state and on-off degree is arranged at the bottom, positioned on the rear side of the filter, of the complexing reaction-in-situ filtering area, and the other side of the discharge baffle is communicated with the top of the cross-linking reaction area; the vertical section of the cross-linking reaction area is of a trapezoidal structure with a wide upper part and a narrow lower part; the dryer is connected with the bottom of the cross-linking reaction zone; and the double-tower circulation type thermal decomposition system is used for fluidizing the solid complex dried by the circulation thermal decomposition dryer and discharging hydrogen fluoride-containing gas.

Description

Technical Field

[0001] This invention relates to the field of chemical technology, specifically to an apparatus for preparing hydrogen fluoride by molecular recognition complexation and its application. Background Technology

[0002] Hydrogen fluoride, as a basic raw material, is the cornerstone of the fluorochemical industry and a key starting point for the production of various fluorides, supporting the operation of the entire industrial chain. As the fluorochemical industry develops towards refinement and large-scale production, the stability of anhydrous hydrogen fluoride supply is crucial for the healthy development of national strategic emerging industries such as new energy, new materials, semiconductors, and pharmaceuticals.

[0003] The fluorosilicic acid sulfuric acid decomposition method is an important industrial process for the production of hydrogen fluoride. Its core feature is that it realizes the resource utilization of by-products from the phosphate fertilizer industry, turning waste into treasure. It is a typical circular economy path. However, the process generates a large amount of dilute sulfuric acid, which brings huge environmental pressure. Therefore, whether the dilute sulfuric acid problem can be solved is the key to the rational utilization of this resource.

[0004] The sulfuric acid decomposition method in existing hydrogen fluoride preparation technologies has environmental problems due to the generation of large amounts of dilute sulfuric acid. Researchers have developed some alternative technologies.

[0005] The following existing technologies were found through a search: Patent specification CN116835597A discloses a multi-stage extraction and concentration process for dilute fluorosilicic acid. This process uses alcohol-based organic compounds as extractants to extract and concentrate the dilute fluorosilicic acid, and adds polar or non-polar organic compounds as auxiliaries to the extractants. The extractants are then recovered using vacuum distillation. However, this extraction method for hydrogen fluoride preparation suffers from problems such as low extraction efficiency, significant extractant loss, and complex process flow.

[0006] The patent specification with publication number CN113816340A discloses a method for preparing anhydrous hydrogen fluoride and co-producing silicon tetrafluoride from sodium fluorosilicate. The method involves a fluidized bed gas-solid reaction between sodium fluorosilicate and hydrogen chloride gas to obtain crude anhydrous hydrogen fluoride, which is then purified to obtain pure anhydrous hydrogen fluoride.

[0007] The patent specification with publication number CN106865500A discloses a cyclic production process for preparing hydrogen fluoride from fluorosilicic acid. The process involves mixing and reacting fluorosilicic acid with alkaline earth metal fluorides or alkali metal fluorides to obtain a mixed solution of hydrogen fluoride and fluorosilicate. This solution is then further used to obtain hydrogen fluoride gas and fluorosilicate solid. The fluorosilicate solid is then heated and decomposed to obtain fluoride solid and silicon tetrafluoride gas. The silicon tetrafluoride gas is absorbed by a fluorosilicic acid solution.

[0008] The patent specification with announcement number CN117208912B proposes a process for purifying and concentrating dilute fluorosilicic acid solution by chemical extraction. It uses organic base or modified organic base as extractant and inorganic acid as back-extraction agent. The dilute fluorosilicic acid is concentrated through chemical extraction and chemical back-extraction. The auxiliary agent is recovered by vacuum distillation and the extractant is recovered by vacuum heating decomposition.

[0009] Patent specification CN120646865A discloses a comprehensive utilization method for fluorosilicic acid containing hydrogen fluoride, comprising the following steps: 1) reacting a raw solution containing fluorosilicic acid with potassium fluoride raw material, and obtaining potassium fluorosilicate and hydrofluoric acid solution after solid-liquid separation; 2) reacting potassium fluorosilicate with sodium hydroxide raw material, and obtaining a mixture of potassium fluoride solution, sodium fluoride and silicon dioxide after solid-liquid separation; the potassium fluoride solution is returned to step 1) as a potassium fluoride raw material for recycling. The main problems with this process are the high gas-solid reaction temperature and high energy consumption cost.

[0010] However, most of the novel hydrogen fluoride preparation processes proposed in the above-mentioned existing technologies have many problems such as complex process flow, large amount of solid waste by-products, and low fluorine recovery rate, making them difficult to industrialize. Against this background, developing a new process to replace the existing sulfuric acid decomposition method for preparing hydrogen fluoride, which can solve the environmental problems of large amounts of dilute sulfuric acid, can also achieve efficient and low-cost preparation of hydrogen fluoride, and is of great significance for helping to improve the sustainable development of the fluorochemical industry. Summary of the Invention

[0011] To address the aforementioned technical problems and shortcomings in this field, the present invention provides an apparatus for preparing hydrogen fluoride using a molecular recognition complexation method and its application. The apparatus comprises an integrated partitioned reactor, a dryer, and a dual-tower circulating thermal decomposition system connected in sequence. The integrated partitioned reactor includes a complexation reaction-in-situ filtration zone and a cross-linking reaction zone. Within the complexation reaction-in-situ filtration zone, a helical propeller stirrer and a filter are arranged sequentially from front to back. The filter is vertically arranged, with its filtration surface perpendicular to the material flow direction propelled by the helical propeller stirrer. At the bottom of the complexation reaction-in-situ filtration zone, behind the filter, is a discharge baffle with adjustable on / off states and degrees; the other side of the discharge baffle connects to the top of the cross-linking reaction zone. The cross-linking reaction zone has a trapezoidal structure with a wider top and narrower bottom. The dryer is connected to the bottom of the cross-linking reaction zone. The dual-tower circulating thermal decomposition system is used to dry the solid complexes in the fluidized bed circulating isothermal thermal decomposition dryer and discharge hydrogen fluoride-containing gas. In this invention, a specially designed molecular recognition complexation system is used to prepare anhydrous hydrogen fluoride of superior grade by combining an integrated partitioned reactor and a dual-tower circulating reaction system. This method has technical advantages such as high fluorosilicic acid complexation rate (≥99.7%), high complex decomposition rate (≥98.5%), and high total yield of anhydrous hydrogen fluoride (≥96.5%).

[0012] The specific technical solution is as follows: In a first aspect, the present invention provides an apparatus for preparing hydrogen fluoride by molecular recognition complexation, comprising an integrated partitioned reactor, a dryer, and a dual-tower circulating thermal decomposition system connected in sequence; The integrated zoned reactor integrates complexation reaction, in-situ filtration, and cross-linking reaction functions, including a complexation reaction-in-situ filtration zone and a cross-linking reaction zone. Within the complexation reaction-in-situ filtration zone, a helical propeller agitator and a filter are arranged sequentially from front to back. The filter is vertically arranged, with its filtration surface perpendicular to the material flow direction propelled by the helical propeller agitator. At the bottom of the complexation reaction-in-situ filtration zone, behind the filter, is a discharge baffle with adjustable on / off status and degree of on / off. The other side of the discharge baffle connects to the top of the cross-linking reaction zone. The cross-linking reaction zone has a trapezoidal structure with a wider top and narrower bottom. The dryer is connected to the bottom of the cross-linking reaction zone and is used to dry the solid complexes that have completed cross-linking in the cross-linking reaction zone. The dual-tower circulating pyrolysis system is used in fluidized bed circulating pyrolysis dryers to dry solid complexes and discharge gases containing hydrogen fluoride.

[0013] The complexation reaction-in-situ filtration zone continuously or semi-continuously completes the selective recognition and capture of fluorosilicic acid molecules through a molecular recognition complexation system, forming a primary complex. This primary complex is gradually pushed towards the filtration end to complete filtration. The filtrate is discharged from the integrated partitioned reactor, while the primary complex enters the cross-linking reaction zone to continue the cross-linking reaction. Under suitable conditions, the primary complex and the cross-linking agent form a stable network structure through the cross-linking reaction, thereby ensuring that the network structure can be maintained at room temperature and dry temperature.

[0014] This invention installs a helical propeller agitator at the front end (feed end) of the complexation reaction-in-situ filtration zone to directionally convey materials towards the filter end while simultaneously achieving thorough mixing. Furthermore, this helical propeller agitator structure integrates material conveying, reaction mixing, and subsequent filtration into a single unit, realizing a forced, pump-free, continuous process from feed to filtration. The filter, under the thrust of the helical propeller agitator, achieves dynamic cross-flow filtration of the reactants, effectively preventing filter pore clogging.

[0015] The helical propulsion mixer includes a motor, a rotating main shaft, and a helical propulsion unit. The motor drives the rotating main shaft to rotate. The rotating main shaft is a solid or hollow rigid shaft that runs through the mixing zone. The helical propulsion unit includes continuous helical ribbon blades that are fixedly installed on the rotating main shaft.

[0016] The filter is generally a precision filtration module, which can be selected from any type such as candle filter or membrane filter.

[0017] The aspect ratio of the complexation reaction-in-situ filtration zone is 1~15:1, preferably 3~8:1.

[0018] The rotation speed of the spiral propeller mixer is 50~500 rpm, preferably 80~200 rpm.

[0019] The cross-linking reaction zone of the trapezoidal structure has a wider upper surface than lower surface, and its two side walls are inwardly sloping surfaces or smooth curved surfaces. This geometric configuration causes the cross-sectional area of ​​the reaction zone to gradually converge and decrease along the downward direction of the material or the direction of the reaction process. The wide upper region of the trapezoidal structure provides ample space for the injection and mixing of primary complexes, which is conducive to achieving uniform dispersion in the early stage of the cross-linking reaction. As the material moves downward, the cross-section gradually narrows, and the linear velocity of the fluid increases accordingly, thereby generating a moderate shearing and squeezing effect. On the one hand, this promotes the contact between unreacted functional groups and enhances the reaction kinetics; on the other hand, it forces the material to flow in a directional manner, reducing backmixing and making the reaction process more orderly and uniform in spatial distribution. The angle between the two sides of the trapezoidal structure and the vertical direction is 5°~80°, preferably 15°~45°. If the angle is too small, the convergence effect will be insufficient; if the angle is too large, it may lead to poor material flow.

[0020] The present invention sets up a discharge baffle between the complexation reaction-in-situ filtration zone and the cross-linking reaction zone to achieve physical isolation or interconnection between the two zones. During operation, the discharge baffle can be opened or closed according to different complexation systems, complexation reaction effects and filtration effects. Furthermore, the opening degree of the discharge baffle can be adjusted to ensure the optimal complexation reaction-in-situ filtration effect.

[0021] The dryer can be any of the following: spray dryer, fluidized bed dryer, belt dryer, chamber dryer, vacuum rake dryer, double cone rotary dryer, etc.

[0022] The dryer can reduce the water content of solid complex materials to below 0.5 wt%.

[0023] The dual-tower circulating pyrolysis system comprises a first circulating pyrolysis tower and a second circulating pyrolysis tower. An upper circulating channel, a middle circulating channel, and a lower circulating channel are provided between the first and second circulating pyrolysis towers. The material flow direction in the upper circulating channel is from the first circulating pyrolysis tower to the second circulating pyrolysis tower; the material flow direction in the middle circulating channel is from the first circulating pyrolysis tower to the second circulating pyrolysis tower or vice versa; and the material flow direction in the lower circulating channel is from the second circulating pyrolysis tower to the first circulating pyrolysis tower. This achieves interconnection and circular flow of materials within the first and second circulating pyrolysis towers. This specific flow direction facilitates the equalization of the material temperature and concentration gradients, enabling the complex to undergo pyrolysis at an equilibrium temperature, thereby maintaining a stable and efficient gas production rate and process controllability. The upper circulation channel is positioned higher at the interface of the first circulation pyrolysis tower than at the interface of the second circulation pyrolysis tower. The angle between the upper circulation channel and the horizontal direction is 1° to 60°, preferably 5° to 30°. The middle circulation channel is horizontal. The lower circulation channel is positioned lower at the interface of the first circulation pyrolysis tower than at the interface of the second circulation pyrolysis tower. The angle between the lower circulation channel and the horizontal direction is 1° to 60°, preferably 5° to 30°.

[0024] The dryer is connected to the first circulating pyrolysis tower, and the connection is located between the middle circulating channel and the lower circulating channel.

[0025] The first and second circulating pyrolysis towers are equipped with gas outlets at the top and carrier gas inlets below the lower circulating channel. Below the carrier gas inlets is the outlet for the molecular recognition complexing system. The carrier gas inlet serves two purposes: firstly, to achieve circulating flow between the first and second circulating pyrolysis towers, ensuring timely and uniform overall reaction temperature, allowing the complex to decompose under near-isothermal conditions; secondly, to provide continuous fluidization power for the solid complex decomposition process, enabling rapid surface renewal and improving decomposition efficiency; and thirdly, the introduction of carrier gas can instantly carry away the decomposition gas, forming a stable flow rate, making the pyrolysis process more stable and controllable.

[0026] In both the first and second circulating pyrolysis towers, a gas-liquid separation component is installed between the gas outlet and the upper circulating channel. This component separates the liquid entrained in the mixture of rising carrier gas and decomposed gas within the tower. The separated gas phase is discharged through the gas outlet at the top of the tower, while the separated liquid phase returns to the tower. The gas-liquid separation component can generally be one or a combination of baffle structures, cyclone / centrifugal structures, packing materials, and wire mesh structures.

[0027] In both the first and second circulating pyrolysis towers, an outlet collector with flow stabilization and filtration functions is installed at the front end of the molecular recognition complexation system discharge port. The outlet collector is a component with flow stabilization and filtration functions, fixed at the bottom of the first and second circulating pyrolysis towers before the molecular recognition complexation system discharge port. It consists of a cross-shaped anti-vortex baffle, steel bars, and wire mesh. Multiple steel bars form an external support frame, with the cross-shaped anti-vortex baffle inside. Wire mesh is bound to the outside of the frame. When the material at the bottom of the tower flows through the outlet collector, it is first filtered by the outer wire mesh before entering the support frame. The cross-shaped anti-vortex baffle then rectifies the flow, breaking up large-scale turbulence before discharge. The molecular recognition complexation system discharge port is connected to the complexation reaction-in-situ filtration zone.

[0028] The apparatus for preparing hydrogen fluoride by molecular recognition complexation further includes a hydrogen fluoride separation tower and a hydrogen fluoride purification tower; the dual-tower circulating thermal decomposition system, the hydrogen fluoride separation tower, and the hydrogen fluoride purification tower are connected in sequence. The hydrogen fluoride separation tower is used to separate the hydrogen fluoride obtained from the thermal decomposition of the dual-tower circulating thermal decomposition system with a silicon tetrafluoride mixed gas by distillation, obtaining crude hydrogen fluoride gas and silicon tetrafluoride gas. Preferably, the top pressure of the hydrogen fluoride separation tower is 0.8~2.0 MPa, the top temperature is 5~30°C, and the bottom temperature is 60~90°C. The hydrogen fluoride purification tower is used to further purify the crude hydrogen fluoride gas obtained from the distillation separation in the hydrogen fluoride separation tower, obtaining anhydrous hydrogen fluoride. Preferably, the top pressure of the hydrogen fluoride purification tower is 0.2~1.0 MPa, the top temperature is 20~25°C, and the bottom temperature is 30~40°C.

[0029] The apparatus for preparing hydrogen fluoride using the molecular recognition complexation method further includes a fluorosilicic acid raw material tank and a solid-liquid separation device; the fluorosilicic acid raw material tank, the solid-liquid separation device, and the complexation reaction-in-situ filtration zone are connected in sequence. The hydrogen fluoride separation tower is connected to the fluorosilicic acid raw material tank. The fluorosilicic acid raw material tank is used to receive fluorosilicic acid raw material and silicon tetrafluoride gas (from the hydrogen fluoride separation tower), and to perform hydrolysis of silicon tetrafluoride gas to generate silicon dioxide and fluorosilicic acid. The solid-liquid separation device is used to separate silicon dioxide to obtain a fluorosilicic acid solution. The solid-liquid separation device can be a filter, specifically any one of a bag filter, plate and frame / chamber filter press, belt filter press, rotary drum vacuum filter, candle filter, etc.

[0030] In a second aspect, the present invention provides the application of the apparatus for preparing hydrogen fluoride by the molecular recognition complexation method described in the first aspect for the preparation of hydrogen fluoride.

[0031] Thirdly, the present invention provides a method for preparing hydrogen fluoride by molecular recognition complexation, using the apparatus for preparing hydrogen fluoride by molecular recognition complexation as described in the first aspect; The method for preparing hydrogen fluoride by molecular recognition complexation includes: Fluorosilicic acid solution and molecular recognition complexation system enter an integrated zoned reactor. First, in the complexation reaction-in-situ filtration zone, the complexation reaction and in-situ filtration are completed under the action of a helical propeller stirrer. The filtrate passes through the filter and is discharged. The primary complex generated by the complexation reaction is pushed to the rear of the filter by the helical propeller stirrer. The discharge baffle is opened, and the primary complex enters the cross-linking reaction zone to undergo a cross-linking reaction to obtain a stable network structure complex. The molecular recognition complexation system contains a complexing agent and a cross-linking agent. After being dried in a dryer, the stable network structure complex enters a dual-tower circulating thermal decomposition system for fluidized bed thermal decomposition and discharges hydrogen fluoride-containing gas.

[0032] The molecular recognition complexation system of this invention contains a complexing agent, an auxiliary agent, and a crosslinking agent, possessing targeted recognition, precise capture, and stable curing functions. The complexing agent is the main component that complexes with fluorosilicic acid, achieving high selectivity, affinity, and responsiveness to the target molecule fluorosilicic acid, and is key to the efficient complexation reaction of fluorosilicic acid. The auxiliary agent provides hydrogen bond donors to enhance the complexing ability, enabling the molecular recognition complexing agent and fluorosilicic acid to achieve rapid complexation, and synergistically improving the complexation rate of the molecular recognition complexing agent. The crosslinking agent bridges the complex molecules to form a structural network, thereby stabilizing the complex. Specifically, it involves the controllable curing of the complex molecules formed by the molecular recognition complexing agent and fluorosilicic acid, allowing them to bridge and form a stable multidimensional network structure complex. During the mixing and propulsion process of the spiral propeller agitator, a complexation reaction occurs. In this process, the fluorosilicic acid molecules in the fluorosilicic acid raw material react rapidly with the molecular recognition complexation system (crosslinking agent, complexing agent and auxiliary agent) to form a solid primary complex. After filtration by the filter at the end of the complexation reaction-in-situ filtration zone, the filtrate containing only the water that did not participate in the reaction and trace amounts of the molecular recognition complexation system in the fluorosilicic acid raw material is discharged. The remaining wet material enters the crosslinking reaction zone after the discharge baffle is opened to carry out the crosslinking reaction to form a stable network structure complex.

[0033] The complexing agent comprises one or more of N-alkyl-substituted aromatic amine compounds, P-alkyl-substituted aromatic phosphorus compounds, N-alkyl-substituted aromatic phosphorus compounds, and alkyl-substituted aromatic sulfur compounds. The N-alkyl-substituted aromatic amine compounds preferably comprise one or more of N-methylaniline, N-ethylaniline, N-methylpyrrole, N-n-butylaniline, N,N-dimethylaniline, N-isopropyl-1-naphthylaniline, N,N-diethylaniline, N,N-dimethyl-1-naphthylaniline, N,N-dibutylaniline, N-methyl-4-aminoaniline, N-ethyl-N-methylaniline, N-isopropylaniline, N-tert-butylaniline, and N-pyrrolidinylaniline. The p-alkyl-substituted aromatic phosphorus compounds preferably include one or more of triphenylphosphine, methylphenylphosphine, phenyl tert-butylphosphine, phenyl dicyclohexylphosphine, p,p-dimethylphenylphosphine, p,p-dibutylphenylphosphine, p,p-diphenylbutylphosphine, p,p-diethylphenylphosphine, phenyl dicyclohexylphosphine, and diethyl phenyl phosphite. The n-alkyl-substituted aromatic phosphorus compounds preferably include one or more of diphenyl(N,N-dimethylamino)phosphine, ditert-butyl(N,N-diethylamino)phosphine, phosphodiamid, hexamethylphosphoric acid triamine, phenylbis(dimethylamino)phosphine, and hexamethylphosphoric acid triamine (HMPA). The alkyl-substituted aromatic sulfur compound preferably includes one or more of the following: 2-methylbenzylthiophenol, 4-tert-butylbenzylthiophenol, 2-ethylphenylmethyl sulfide, 4-isopropyldiphenyl sulfide, 4-methylphenylmethyl sulfoxide, 2,4,6-trimethylphenylphenyl sulfone, methyl 4-ethylbenzenesulfonate, methylphenyl sulfide, ethylphenyl sulfide, butylphenyl sulfide, methylphenyl sulfoxide, methylphenyl sulfone, and methyl benzenesulfonate.

[0034] The adjuvant preferably includes one or more of long-chain fatty alcohols, long-chain fatty acids, amides, and alkylphenols, and more preferably includes one or more of n-hexanol, n-octanol, lauryl alcohol, stearic acid, lauric acid, n-decanoic acid, formamide, acetamide, N,N-dimethylformamide, N-methylpyrrolidone, nonylphenol, octylphenol, and 2,4-di-tert-butylphenol. The mass ratio of the complexing agent to the adjuvant is preferably 100:1 to 1:1, and more preferably 50:1 to 2:1. Based on the total mass of the molecular recognition complexation system as 100%, the mass percentage of the adjuvant is preferably 0.5% to 30%, and more preferably 1% to 15%.

[0035] The principle of the complexation reaction in this invention is based on fluorosilicate (SiF6) ions. 2- [SiF6] is a strong ligand and complexes with the complexing agent described in this invention to form a complex containing [SiF6]. 2-The unit has a polynuclear complex structure, in which there are both NH···F, SH···F, or PH···F hydrogen bond networks, and weaker CH··F hydrogen bonds formed by the CH groups of the cyclic compound. In principle, the complex can be liquid or solid depending on the molecular structure of the complexing agent and the structure of the complex itself; the final stable state of the complex in this invention should be solid. Furthermore, when screening complexes for industrial applications, not only the complexing ability of the complexing agent must be considered, but also the dissociation ability of the formed coordinate bonds. That is, the complex must be able to decompose under mild and suitable conditions to achieve the technical effect of recycling. Therefore, this invention screens complexing agents that can rapidly complex with fluorosilicic acid to produce stable solid complexes, and can easily and completely decompose without chemical deterioration, realizing a closed-loop process for the production of hydrogen fluoride by fluorosilicic acid complexation.

[0036] The crosslinking agent of this invention works by bridging two or more molecules, thereby connecting these molecules into a more stable structural network, resulting in a stable complex and a mixture of water. This stable complex is a terminal solid complex. The crosslinking agent preferably includes one or more of the following: 1,4-diiodobutane, 1,6-dibromohexane, 1,4-dichlorobutane, glutaraldehyde, methyl ethyl ketone peroxide, dicumyl peroxide, diethylenetriamine, adipic acid chloride, and diisocyanate. Based on the total mass of the molecular recognition complexing system being 100%, the mass percentage of the crosslinking agent is preferably 0.01% to 5%, more preferably 0.05% to 0.5%.

[0037] The source of the fluorosilicic acid solution and its concentration are not limited in principle in this invention. This invention is particularly effective for systems containing low concentrations of fluorosilicic acid, achieving results that conventional extraction systems and devices cannot. In some embodiments, the mass concentration of fluorosilicic acid in the solution is 0.05% to 40%, for example, 0.2%, 10%, 20%, etc. For instance, the standard commercial product concentration after purification from phosphate fertilizer plant by-products is 30% to 34%, or the concentration of intermediate products from phosphate fertilizer by-products is 10% to 20%.

[0038] The molar ratio of fluorosilicic acid to the complexing agent in the fluorosilicic acid solution is preferably 15:1 to 1:15, and more preferably 5:1 to 1:5.

[0039] The preferred temperature for the complexation reaction in this invention is 5-60°C, more preferably 5-35°C. The complexation reaction needs to be carried out under appropriately low temperature conditions in order to minimize the decomposition of fluorosilicic acid and reduce the complexation product. However, since the crosslinking agent is not very effective at this low temperature, the resulting product is a mixture of metastable complex and water.

[0040] The pressure for the complexation reaction is preferably atmospheric pressure to 1.0 MPa, and more preferably atmospheric pressure to 0.15 MPa.

[0041] The preferred time for the complexation reaction is 1 to 120 minutes, such as 5 minutes, 20 minutes, 30 minutes, 60 minutes, etc., and more preferably 2 to 40 minutes.

[0042] The temperature of the crosslinking reaction is preferably 6~85℃, for example 10℃, and more preferably 15~60℃.

[0043] The pressure for the crosslinking reaction is preferably atmospheric pressure to 1.0 MPa, and more preferably atmospheric pressure to 0.15 MPa.

[0044] Preferably, the temperature of the cross-linking reaction is 1-30°C higher than the temperature of the complexation reaction, for example, 10°C, 15°C, etc. More preferably, the temperature of the cross-linking reaction is 5-20°C higher than the temperature of the complexation reaction.

[0045] The cross-linking reaction time is preferably 1 to 20 minutes, and more preferably 2 to 10 minutes.

[0046] The preferred temperature for thermal decomposition is 120~450℃, more preferably 150~350℃, such as 320℃.

[0047] The pressure for thermal decomposition is preferably 0.1~1.0 MPa, more preferably 0.12~0.50 MPa, such as 0.20 MPa.

[0048] The thermal decomposition time is preferably 1 to 200 min, such as 10 min, 30 min, 50 min, 100 min, 120 min, etc., and more preferably 10 to 120 min.

[0049] The carrier gas described in this invention can be a high-purity inert gas, such as high-purity nitrogen (purity > 99.999%), high-purity argon (purity > 99.999%), high-purity helium (purity > 99.999%), or a mixture of the above high-purity gases. The carrier gas flow rate must not only ensure the fluidization of the solid complex particles but also enable the carrier gas, in conjunction with the liquid, to propel the overall material in a circulating flow between the first and second circulating pyrolysis towers. The carrier gas in the first and second circulating pyrolysis towers... The inlet gas velocity is 0.56~1.45m / s. Here, the lower limit of the carrier gas inlet refers to the solid complex particles being able to circulate while being fluidized in the first and second circulating pyrolysis towers. Below this gas velocity, circulation is not smooth. The upper limit of the carrier gas inlet refers to the final velocity of the solid complex particles when they can fall at a uniform speed in both the first and second circulating pyrolysis towers. Above this gas velocity, on the one hand, the solid particles will be carried away by the airflow and cannot fall back, and on the other hand, circulation between the two towers cannot be achieved.

[0050] Those skilled in the art should understand that hydrogen fluoride is a crucial basic raw material supporting the development of national strategic emerging industries. It connects limited strategic mineral resources on one end and drives unlimited technological innovation and industrial upgrading on the other. Its development level directly reflects a nation's comprehensive competitiveness in high-tech manufacturing, new materials, and fine chemicals. In hydrogen fluoride preparation processes, the production of anhydrous hydrogen fluoride from fluorosilicic acid, a byproduct of the phosphate fertilizer industry, produces HF. This not only solves the environmental problems of the phosphate fertilizer industry but also opens up a non-fluorite-derived HF route, representing a circular economy. However, the mainstream direct sulfuric acid decomposition process generates significant environmental pressure due to the large amount of dilute sulfuric acid produced, which urgently needs to be addressed. Against this backdrop, researchers in the hydrogen fluoride preparation industry have developed new processes such as fluoride conversion and chemical extraction, but these all suffer from industrial conversion challenges such as complex process flows, high thermal decomposition temperatures, low fluorine recovery rates, high material and energy consumption, low extraction rates, and severe extractant losses. This invention develops an apparatus for preparing hydrogen fluoride using a molecular recognition complexation method and its application. On the one hand, it differs from the traditional direct decomposition method of sulfuric acid by eliminating the use of concentrated sulfuric acid. On the other hand, based on the use of a special molecular recognition complexation system, apparatus, and process, it has a strong ability to distinguish and capture specific target fluorosilicic acid molecules, exhibiting ultra-high selectivity and affinity for fluorosilicic acid molecules. Therefore, it can achieve a high fluorine extraction rate and realize the efficient preparation of hydrogen fluoride, which is of great significance for ensuring the resilience of the fluorochemical industry chain.

[0051] Compared with the prior art, the beneficial effects of this invention are as follows: 1) In this invention, a special molecular recognition complexation system is used as a circulating complexation carrier. After the complexation reaction occurs in the integrated partitioned reactor, hydrogen fluoride is continuously generated in the dual-tower circulating thermal decomposition system. While achieving efficient preparation of hydrogen fluoride, the use of concentrated sulfuric acid is eliminated, thus solving the environmental problem of generating a large amount of dilute sulfuric acid in the existing direct decomposition method of sulfuric acid to prepare hydrogen fluoride.

[0052] 2) The integrated partitioned reactor used in this invention enables precise complexation, efficient reaction, and timely solidification of the molecular recognition complexation system with fluorosilicic acid molecules to form stable complexes, which is an important basis for high fluorine extraction rate. Furthermore, the stable complexes are decomposed at near isothermal temperature in a dual-tower circulating thermal decomposition system, and a stable gas flow containing hydrogen fluoride and a recyclable molecular recognition complexation system are obtained under the impetus of a carrier gas. This allows the complex decomposition process to be carried out under mild conditions, resulting in more efficient, stable, and controllable technical effects, making this process easy to implement industrially. Attached Figure Description

[0053] Figure 1 This is a schematic diagram of an apparatus for preparing hydrogen fluoride using a molecular recognition complexation method according to the present invention. Detailed Implementation

[0054] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Operating methods not specifically specified in the following embodiments are generally performed under conventional conditions or as recommended by the manufacturer.

[0055] Example 1: See Figure 1 An apparatus for preparing hydrogen fluoride using a molecular recognition complexation method includes, in sequence, a fluorosilicic acid raw material tank 3, a fluorosilicic acid discharge pump 5, a solid-liquid separation device 6, an integrated partitioned reactor 9, a dryer 19, a dual-tower circulating thermal decomposition system, a hydrogen fluoride separation tower 31, and a hydrogen fluoride refining tower 33. The hydrogen fluoride separation tower 31 is also connected to the fluorosilicic acid raw material tank 3.

[0056] The integrated zoned reactor 9 integrates complexation reaction, in-situ filtration, and cross-linking reaction functions, comprising a complexation reaction-in-situ filtration zone 12 and a cross-linking reaction zone 13. The complexation reaction-in-situ filtration zone 12 has a horizontal rectangular structure, with a helical propeller agitator 16 and a filter 14 arranged sequentially from front to back inside. The helical propeller agitator 16 is mounted on a support 18 and includes a motor 15, a rotating main shaft connected to the motor 15, and continuous helical blades fixedly mounted on the rotating main shaft. The filter 14 is vertically arranged, with its filtration surface perpendicular to the material flow direction propelled by the helical propeller agitator 16. At the bottom rear of the filter 14, the complexation reaction-in-situ filtration zone 12 has an adjustable discharge baffle 17, with its other side connected to the top of the cross-linking reaction zone 13. The cross-linking reaction zone 13 has a trapezoidal vertical cross-section, wider at the top and narrower at the bottom.

[0057] The inlet of the dryer 19 is connected to the bottom of the cross-linking reaction zone 13 and is used to dry the solid complex that has completed cross-linking in the cross-linking reaction zone 13.

[0058] The dual-tower circulating pyrolysis system is used in the fluidized bed circulating pyrolysis dryer 19 to dry solid complexes and discharge gases containing hydrogen fluoride.

[0059] The dual-tower circulating pyrolysis system includes a first circulating pyrolysis tower 21A and a second circulating pyrolysis tower 21B. An upper circulating channel 26, a middle circulating channel 27, and a lower circulating channel 28 are provided between the first circulating pyrolysis tower 21A and the second circulating pyrolysis tower 21B. The material flow direction in the upper circulating channel 26 is from the first circulating pyrolysis tower 21A to the second circulating pyrolysis tower 21B; the material flow direction in the middle circulating channel 27 is from the first circulating pyrolysis tower 21A to the second circulating pyrolysis tower 21B or from the second circulating pyrolysis tower 21B to the first circulating pyrolysis tower 21A; and the material flow direction in the lower circulating channel 28 is from the second circulating pyrolysis tower 21B to the first circulating pyrolysis tower 21A. The interface position of the upper circulating channel 26 at the first circulating pyrolysis tower 21A is higher than the interface position at the second circulating pyrolysis tower 21B. The middle circulation channel 27 is horizontal. The lower circulation channel 28 is positioned at a lower level than the interface of the first circulation pyrolysis tower 21A compared to the interface of the second circulation pyrolysis tower 21B. A solid complex material inlet 20, connecting to the outlet of the dryer 19, is located on the side of the first circulation pyrolysis tower 21A between the middle circulation channel 27 and the lower circulation channel 28. A first gas outlet 23A is located at the top of the first circulation pyrolysis tower 21A, and a first carrier gas inlet 22A is located below the lower circulation channel 28. A first molecular recognition complex system outlet 24A is located below (at the bottom) of the first carrier gas inlet 22A, and a first outlet collector 29A with flow stabilization and filtration functions is located at the front end of the first molecular recognition complex system outlet 24A. A first gas-liquid separation component 25A is located inside the first circulation pyrolysis tower 21A between the first gas outlet 23A and the upper circulation channel 26. The second circulating pyrolysis tower 21B has a second gas outlet 23B at its top and a second carrier gas inlet 22B below the lower circulating channel 28. Below (at the bottom) of the second carrier gas inlet 22B is a first molecular recognition complexation system outlet 24B. A second outlet collector 29B with flow stabilization and filtration functions is installed at the front end of the second molecular recognition complexation system outlet 24B. A second gas-liquid separation component 25B is installed inside the second circulating pyrolysis tower 21B between the second gas outlet 23B and the upper circulating channel 26. The first molecular recognition complexation system outlet 24A and the second molecular recognition complexation system outlet 24B are connected to the complexation reaction-in-situ filtration zone 9 via a molecular recognition complexation system outlet pump 30.

[0060] The apparatus described above for preparing hydrogen fluoride using the molecular recognition complexation method can be used to prepare hydrogen fluoride.

[0061] A method for preparing hydrogen fluoride using a molecular recognition complexation method, comprising an apparatus for preparing hydrogen fluoride using the aforementioned molecular recognition complexation method, including: Fluorosilicic acid raw material 1 and silicon tetrafluoride gas 2 (which may contain carrier gas) are concentrated in fluorosilicic acid raw material tank 3. The resulting fluorosilicic acid raw material discharge 4 is sent to solid-liquid separation equipment 6 for filtration via fluorosilicic acid discharge pump 5. The resulting fluorosilicic acid solution 7 and molecular recognition complexation system 8 are used as feed to integrated partitioned reactor 9. The complexation reaction and in-situ filtration are first completed in the complexation reaction-in-situ filtration zone 12 under the action of helical propeller stirrer 16. The filtrate 10 is discharged through filter 14. The primary complex generated by the complexation reaction is pushed to the rear of filter 14 by helical propeller stirrer 16. The discharge baffle 17 is opened, and the primary complex enters the cross-linking reaction zone 13 to undergo cross-linking reaction to obtain a stable network structure complex 11. The molecular recognition complexation system contains a complexing agent and a cross-linking agent. Specifically, during the complexation reaction, while the material system containing the primary complex is stirred and mixed by helical propeller stirrer 16, it is pushed forward and pushed to filter 14 for filtration. The filtrate 10 is discharged from integrated partitioned reactor 9. A helical propeller agitator 16 is horizontally integrated within the integrated partitioned reactor 9. A filter 14 is located at the rear end of the helical propeller agitator 16, within the cavity of the integrated partitioned reactor 9. The discharged filtrate 10 can be connected to a vacuum system to enhance the filtration effect. A discharge baffle 17 is horizontally positioned adjacent to the rear end of the filter 14, between the complexation reaction-filtration zone 12 and the crosslinking reaction zone 13. After a certain residence time in the complexation reaction, the discharge baffle 17 can be opened according to different complex systems, complexation reaction conditions, filtration effects, etc., to send the primary complex to the crosslinking reaction zone 13 for crosslinking.

[0062] After being dried by dryer 19, the stable network structure complex 11 enters the first circulating pyrolysis tower 21A through solid complex material inlet 20. Within the dual-tower circulating pyrolysis system, it undergoes near-constant temperature fluidized bed pyrolysis and discharges hydrogen fluoride-containing gas. The upper circulating channel 26, middle circulating channel 27, and lower circulating channel 28 serve as material flow channels between the first circulating pyrolysis tower 21A and the second circulating pyrolysis tower 21B, ensuring uniform heat of reaction throughout the entire dual-tower circulating pyrolysis system. Carrier gas 22 is introduced into the first carrier gas inlet 22A of the first circulating pyrolysis tower 21A and the second carrier gas inlet 22B of the second circulating pyrolysis tower 21B. This serves two purposes: firstly, to achieve circulating flow between the first circulating pyrolysis tower 21A and the second circulating pyrolysis tower 21B, uniformly controlling the reaction temperature and allowing the complex to decompose under near-isothermal conditions; secondly, to provide continuous fluidization power for the decomposition process of the solid complex, enabling rapid surface renewal and improving decomposition efficiency. Furthermore, the introduction of carrier gas 22 can instantly carry away the decomposition gas, forming a stable flow rate, making the operation of the pyrolysis process more stable and controllable.

[0063] The mixed gas 23, containing carrier gas, silicon tetrafluoride, and hydrogen fluoride gas, obtained from the dual-tower circulating pyrolysis system, is discharged from the top. The resulting liquid output 24 is filtered and rectified by the first outlet collector 29A and the second outlet collector 29B, and then discharged from the bottom. After being drawn out by the molecular recognition complexation system discharge pump 30, it is recycled back to the complexation reaction-in-situ filtration zone 12 as part of the molecular recognition complexation system 8. The mixed gas 23 is first separated by distillation in the hydrogen fluoride separation tower 31. At the top of the tower, silicon tetrafluoride gas 2, with or without carrier gas, is obtained and recycled to the fluorosilicic acid raw material tank 3 for concentration. The crude hydrogen fluoride 32 obtained at the bottom of the tower enters the hydrogen fluoride refining tower 33 for purification, finally yielding anhydrous hydrogen fluoride product 34.

[0064] Example 2: Hydrogen fluoride products were prepared using the apparatus and method for preparing hydrogen fluoride by the molecular recognition complexation method described in Example 1.

[0065] The fluorosilicic acid raw material solutions were prepared using four different concentrations of fluorosilicic acid: 0.8%, 4.5%, 18.7%, and 35%.

[0066] The molecular recognition complex system is designated as No. 1, and its components and contents are shown in Table 1.

[0067] Table 1. Composition of the molecular recognition complex system The specific methods include: (1) continuously completing the complexation and cross-linking reactions of the molecular recognition complexation system and the fluorosilicic acid solution in an integrated partitioned reactor to generate primary complexes and stable complexes in sequence; (2) after drying the stable complexes, introducing them into a double-tower circulating thermal decomposition system, so that they undergo isothermal thermal decomposition in the double-tower circulating thermal decomposition system, and obtain gas containing hydrogen fluoride while achieving circulating flow under the drive of the carrier gas, and then obtaining anhydrous hydrogen fluoride products through a hydrogen fluoride distillation system.

[0068] The complexation reaction conditions were as follows: temperature 37℃, pressure at atmospheric pressure; molar ratio of fluorosilicic acid to complexing agent 2.21:1; complexation time 12 min. The aspect ratio of the complexation reaction-in-situ filtration zone is 8:1; the speed of the screw propeller stirrer is 150 rpm.

[0069] The cross-linking reaction conditions are as follows: temperature 43℃, pressure at atmospheric pressure, and cross-linking reaction time 5 min.

[0070] The angle between the two sides of the trapezoidal structure in the cross-linking reaction zone and the vertical direction is 30°.

[0071] The thermal decomposition conditions for the complex were: temperature 224.3~225.5℃; pressure 0.12~0.20MPa; and residence time 35min. The upper circulation channel makes an angle of 15° with the horizontal direction; the lower circulation channel makes an angle of 15° with the horizontal direction.

[0072] The carrier gas is high-purity nitrogen (purity >99.999%), and the gas flow rate is 0.57~1.22m / s.

[0073] After processing using the above methods, the hydrogen fluoride product quality reached the superior grade specifications (key indicators: hydrogen fluoride content ≥99.99%, moisture content ≤0.003%, fluorosilicic acid content ≤0.005%, sulfur dioxide (SO2) <0.003%, and non-volatile acid (calculated as H2SO4) <0.003%). The complexation rate, complex decomposition rate, and total yield of hydrogen fluoride are shown in Table 2.

[0074] Example 3: Hydrogen fluoride products were prepared using the apparatus and method for preparing hydrogen fluoride by molecular recognition complexation in Example 1, and the specific method was similar to that in Example 2.

[0075] The complexation reaction conditions are as follows: temperature 40℃, pressure at atmospheric pressure; molar ratio of fluorosilicic acid to complexing agent 2.23:1; complexation time 10 min. The aspect ratio of the complexation reaction-in-situ filtration zone is 6:1; the speed of the screw propeller stirrer is 150 rpm.

[0076] The cross-linking reaction conditions are as follows: temperature 47℃, pressure at atmospheric pressure, and cross-linking reaction time 4 min.

[0077] The angle between the two sides of the trapezoidal structure in the cross-linking reaction zone and the vertical direction is 30°.

[0078] The thermal decomposition conditions for the complex were: temperature 224.5~226.2℃; pressure 0.12~0.20MPa; and residence time 32min. The upper circulation channel makes an angle of 15° with the horizontal direction; the lower circulation channel makes an angle of 15° with the horizontal direction.

[0079] The carrier gas is high-purity nitrogen (purity >99.999%), and the gas flow rate is 0.72~1.35m / s.

[0080] After processing using the above methods, the hydrogen fluoride product quality reached the superior grade specifications (key indicators: hydrogen fluoride content ≥99.99%, moisture content ≤0.003%, fluorosilicic acid content ≤0.005%, sulfur dioxide (SO2) <0.003%, and non-volatile acid (calculated as H2SO4) <0.003%). The complexation rate, complex decomposition rate, and total yield of hydrogen fluoride are shown in Table 2.

[0081] Example 4: Hydrogen fluoride products were prepared using the apparatus and method for preparing hydrogen fluoride by molecular recognition complexation in Example 1, and the specific method was similar to that in Example 2.

[0082] The complexation reaction conditions were as follows: temperature 38℃, pressure at atmospheric pressure; molar ratio of fluorosilicic acid to complexing agent 2.22:1; complexation time 10 min. The aspect ratio of the complexation reaction-in-situ filtration zone is 3:1; the speed of the screw propeller stirrer is 150 rpm.

[0083] The cross-linking reaction conditions are as follows: temperature 46℃, pressure at atmospheric pressure, and cross-linking reaction time 5 min.

[0084] The angle between the two sides of the trapezoidal structure in the cross-linking reaction zone and the vertical direction is 30°.

[0085] The thermal decomposition conditions for the complex were: temperature 224.6~225.9℃; pressure 0.12~0.20MPa; and residence time 30min. The upper circulation channel makes an angle of 15° with the horizontal direction; the lower circulation channel makes an angle of 15° with the horizontal direction.

[0086] The carrier gas is high-purity nitrogen (purity >99.999%), and the gas flow rate is 0.63~1.17m / s.

[0087] After processing using the above methods, the hydrogen fluoride product quality reached the superior grade specifications (key indicators: hydrogen fluoride content ≥99.99%, moisture content ≤0.003%, fluorosilicic acid content ≤0.005%, sulfur dioxide (SO2) <0.003%, and non-volatile acid (calculated as H2SO4) <0.003%). The complexation rate, complex decomposition rate, and total yield of hydrogen fluoride are shown in Table 2.

[0088] Table 2 As can be seen from Examples 2 to 4, the apparatus and method for preparing hydrogen fluoride using the molecular recognition complexation method of the present invention use a special molecular recognition complexation system as a circulating complexation carrier. After the complexation reaction occurs in an integrated partitioned reactor, hydrogen fluoride is continuously generated in a dual-tower circulating thermal decomposition system. While achieving efficient preparation of hydrogen fluoride, the use of concentrated sulfuric acid is completely eliminated. This solves the environmental problem of generating a large amount of dilute sulfuric acid in the existing direct decomposition method for preparing hydrogen fluoride, while achieving the technical effects of high fluorosilicic acid complexation rate (≥99.7%), high complex decomposition rate (≥98.5%), and high total yield of anhydrous hydrogen fluoride (≥96.5%).

[0089] Furthermore, it should be understood that after reading the above description of the present invention, those skilled in the art can make various alterations or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims.

Claims

1. An apparatus for preparing hydrogen fluoride using a molecular recognition complexation method, characterized in that, It includes an integrated zoned reactor, a dryer, and a dual-tower circulating pyrolysis system connected in sequence; The integrated zoned reactor integrates complexation reaction, in-situ filtration, and cross-linking reaction functions, including a complexation reaction-in-situ filtration zone and a cross-linking reaction zone. Within the complexation reaction-in-situ filtration zone, a helical propeller agitator and a filter are arranged sequentially from front to back. The filter is vertically arranged, with its filtration surface perpendicular to the material flow direction propelled by the helical propeller agitator. At the bottom of the complexation reaction-in-situ filtration zone, behind the filter, is a discharge baffle with adjustable on / off status and degree of on / off. The other side of the discharge baffle connects to the top of the cross-linking reaction zone. The cross-linking reaction zone has a trapezoidal structure with a wider top and narrower bottom. The dryer is connected to the bottom of the cross-linking reaction zone and is used to dry the solid complexes that have completed cross-linking in the cross-linking reaction zone. The dual-tower circulating pyrolysis system is used in fluidized bed circulating pyrolysis dryers to dry solid complexes and discharge gases containing hydrogen fluoride.

2. The apparatus for preparing hydrogen fluoride by molecular recognition complexation according to claim 1, characterized in that, The aspect ratio of the complexation reaction-in-situ filtration zone is 1~15:1, preferably 3~8:

1.

3. The apparatus for preparing hydrogen fluoride by molecular recognition complexation according to claim 1, characterized in that, The rotation speed of the spiral propeller mixer is 50~500 rpm, preferably 80~200 rpm.

4. The apparatus for preparing hydrogen fluoride by molecular recognition complexation according to claim 1, characterized in that, The angle between the two sides of the trapezoidal structure and the vertical direction is 5°~80°, preferably 15°~45°.

5. The apparatus for preparing hydrogen fluoride by molecular recognition complexation according to claim 1, characterized in that, The dual-tower circulating pyrolysis system includes a first circulating pyrolysis tower and a second circulating pyrolysis tower; an upper circulating channel, a middle circulating channel, and a lower circulating channel are provided between the first and second circulating pyrolysis towers. The material flow direction in the upper circulating channel is from the first circulating pyrolysis tower to the second circulating pyrolysis tower; the material flow direction in the middle circulating channel is from the first circulating pyrolysis tower to the second circulating pyrolysis tower or from the second circulating pyrolysis tower to the first circulating pyrolysis tower; and the material flow direction in the lower circulating channel is from the second circulating pyrolysis tower to the first circulating pyrolysis tower. The dryer is connected to the first circulating pyrolysis tower, and the connection is located between the middle circulating channel and the lower circulating channel; The first and second circulating pyrolysis towers are equipped with gas outlets at the top, and carrier gas inlets are located below the lower circulating channel. Below the carrier gas inlets is the outlet for the molecular recognition complexation system. Gas-liquid separation components are installed in the first and second circulating pyrolysis towers between the gas outlet and the upper circulating channel.

6. The apparatus for preparing hydrogen fluoride by molecular recognition complexation according to claim 5, characterized in that, The upper circulation channel is positioned at a higher point than the interface of the second circulation pyrolysis tower at the first circulation pyrolysis tower. The angle between the upper circulation channel and the horizontal direction is 1° to 60°, preferably 5° to 30°. The central circulation channel is horizontal; The lower circulation channel is positioned at a lower interface position in the first circulation pyrolysis tower than in the second circulation pyrolysis tower, and the angle between the lower circulation channel and the horizontal direction is 1° to 60°, preferably 5° to 30°.

7. The apparatus for preparing hydrogen fluoride by molecular recognition complexation according to claim 5, characterized in that, An outlet collector with flow stabilization and filtration functions is installed at the front end of the outlet of the molecular recognition complexation system; The outlet of the molecular recognition complexation system is connected to the complexation reaction-in-situ filtration zone.

8. The apparatus for preparing hydrogen fluoride by molecular recognition complexation according to claim 1, characterized in that, The apparatus for preparing hydrogen fluoride by molecular recognition complexation further includes a hydrogen fluoride separation tower and a hydrogen fluoride refining tower; the dual-tower circulating thermal decomposition system, the hydrogen fluoride separation tower, and the hydrogen fluoride refining tower are connected in sequence. The apparatus for preparing hydrogen fluoride by molecular recognition complexation also includes a fluorosilicic acid raw material tank and a solid-liquid separation device; the fluorosilicic acid raw material tank, the solid-liquid separation device, and the complexation reaction-in-situ filtration zone are connected in sequence; the hydrogen fluoride separation tower is connected to the fluorosilicic acid raw material tank.

9. The apparatus for preparing hydrogen fluoride by molecular recognition complexation according to any one of claims 1 to 8 is used for the preparation of hydrogen fluoride.

10. A method for preparing hydrogen fluoride using a molecular recognition complexation method, characterized in that, An apparatus for preparing hydrogen fluoride using the molecular recognition complexation method as described in any one of claims 1 to 8; The method for preparing hydrogen fluoride by molecular recognition complexation includes: Fluorosilicic acid solution and molecular recognition complexation system enter an integrated zoned reactor. First, in the complexation reaction-in-situ filtration zone, the complexation reaction and in-situ filtration are completed under the action of a helical propeller stirrer. The filtrate passes through the filter and is discharged. The primary complex generated by the complexation reaction is pushed to the rear of the filter by the helical propeller stirrer. The discharge baffle is opened, and the primary complex enters the cross-linking reaction zone to undergo a cross-linking reaction to obtain a stable network structure complex. The molecular recognition complexation system contains a complexing agent and a cross-linking agent. After being dried in a dryer, the stable network structure complex enters a dual-tower circulating thermal decomposition system for fluidized bed thermal decomposition and discharges hydrogen fluoride-containing gas.

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