Hydrogen fluoride preparation device and preparation method adopting molecular identification complexing system circulation

Abstract

The invention discloses a hydrogen fluoride preparation device and preparation method adopting circulation of a molecular identification complexing system. The preparation device comprises a self-filtering type inclined plane reactor, a dryer and a damping type thermal decomposition reactor which are connected in sequence, the self-filtering inclined plane reactor comprises a complex reaction-filtering area and a cross-linking reaction area; the bottom surface of the complexing reaction-filtering area is an inclined surface which is gradually reduced from the center to the edge, and the edge is communicated with the cross-linking reaction area; an axial filter is arranged in the complexing reaction-filtering area along the central axis; a plurality of stirrers are uniformly distributed in the complexing reaction-filtering area around the axial filter; the cross-linking reaction area is a static mixing reaction channel with a high length-diameter ratio; the dryer is connected with the cross-linking reaction area; the damping type thermal decomposition reactor is used for fluidizing the solid complex dried by the thermal decomposition dryer under stable pressure and discharging hydrogen fluoride-containing gas and a molecular identification complexing system; and a molecule identification complexing system discharged by the damping type thermal decomposition reactor is circularly used in the complexing reaction-filtering area.

Description

TECHNICAL FIELD

[0001] The application relates to the chemical technology field, in particular to a hydrogen fluoride preparation device and preparation method adopting a molecular recognition complex system cycle. BACKGROUND

[0002] Hydrogen fluoride is the cornerstone of the fluorine chemical industry. As a basic raw material, it is the key starting point for the production of various fluorides and supports the operation of the entire industrial chain. With the development of fluorine chemical industry towards fine and large-scale, the stability of anhydrous hydrogen fluoride supply is crucial to the healthy development of new energy, new materials, semiconductors, pharmaceuticals and other national strategic emerging industries. In the hydrogen fluoride preparation process, the fluorosilicate sulfuric acid decomposition method is an important process route for the industrial preparation of hydrogen fluoride. Its core feature is to realize the resource utilization of by-products of the phosphate fertilizer industry, turning waste into treasure, which is a typical circular economy path. However, the process is based on the generation of 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 resources.

[0003] In view of the environmental problem of generating a large amount of dilute sulfuric acid in the existing sulfuric acid decomposition method for preparing hydrogen fluoride, patent document CN106865500A discloses a cyclic production process for preparing hydrogen fluoride from fluosilicic acid, which is a mixed reaction of fluosilicic acid and alkaline earth metal fluoride or alkali metal fluoride to obtain a mixed solution of hydrogen fluoride and fluosilicate, and further obtain hydrogen fluoride gas and fluosilicate solid, and then heat and decompose the fluosilicate solid to obtain fluoride solid and silicon tetrafluoride gas, and the silicon tetrafluoride gas is absorbed by a fluosilicic acid solution. Patent document CN113816340A proposes a method for preparing anhydrous hydrogen fluoride and co-producing silicon tetrafluoride from sodium fluosilicate, which is a fluidized bed gas-solid reaction of sodium fluosilicate and hydrogen chloride gas to obtain crude anhydrous hydrogen fluoride, and the gas is further refined to obtain pure anhydrous hydrogen fluoride. Patent document CN120646865A proposes a comprehensive utilization method of fluosilicic acid containing hydrogen fluoride, which includes the following steps: 1) reacting the original solution containing fluosilicic acid with potassium fluoride raw material, and obtaining potassium fluosilicate and hydrofluoric acid solution after solid-liquid separation; 2) reacting potassium fluosilicate 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 recycled as potassium fluoride raw material in step 1). The main problem of this process is that the gas-solid reaction temperature is high and the process energy consumption cost is high. Patent CN117208912B proposes a process for purifying and concentrating dilute fluosilicic acid solution by chemical extraction, which uses organic base or modified organic base as extractant, inorganic acid as stripping agent, and concentrates dilute fluosilicic acid by chemical extraction-chemical stripping, and recovers the auxiliary agent by vacuum distillation and recovers the extractant by vacuum heating decomposition. Patent document CN116835597A proposes a multi-stage extraction concentration process for dilute fluosilicic acid, which uses alcohol organic matter as extractant to extract and concentrate dilute fluosilicic acid, and adds polar or non-polar organic matter as auxiliary agent in the extractant, and recovers the extractant by vacuum distillation. The extraction method for preparing hydrogen fluoride has problems such as low extraction efficiency, large loss of extractant, and complex process flow.

[0004] In summary, the new hydrogen fluoride preparation processes proposed in the above-mentioned patent technologies have many problems such as complex process flow, large amount of solid waste by-product, low fluorine yield, etc., and are difficult to be industrialized. In this background, a new process is developed to replace the existing sulfuric acid decomposition method for preparing hydrogen fluoride, which can solve the environmental problem of generating a large amount of dilute sulfuric acid and also achieve efficient and low-cost preparation of hydrogen fluoride, which is of great significance for promoting the sustainable development of the fluorine chemical industry. SUMMARY

[0005] In view of the above technical problems and deficiencies in the field, the present application provides a hydrogen fluoride preparation device and preparation method using a circulating molecular recognition complex system. The preparation device comprises a self-filtering inclined surface reactor, a dryer and a damping type thermal decomposition reactor connected in sequence; the self-filtering inclined surface reactor comprises a complex reaction-filtering zone and a crosslinking reaction zone; the bottom surface of the complex reaction-filtering zone is an inclined surface gradually decreasing from the center to the edge, and the edge is connected to the crosslinking reaction zone; an axial filter is arranged along the central axis of the complex reaction-filtering zone; a plurality of stirrers are uniformly distributed around the axial filter in the complex reaction-filtering zone; the crosslinking reaction zone is a static mixing reaction channel with a high length-diameter ratio; the dryer is connected to the crosslinking reaction zone; the damping type thermal decomposition reactor is used to fluidize and thermally decompose the solid complex dried by the dryer under stable pressure, and discharge the gas and the molecular recognition complex system; the molecular recognition complex system discharged by the damping type thermal decomposition reactor is recycled for the complex reaction-filtering zone. In the preparation method of hydrogen fluoride, the molecular recognition system constructed has excellent recyclable performance, greatly reduces the production cost, has strong process stability, high production efficiency, a complexation rate of fluorosilicic acid of 99.7% or more, a complex decomposition rate of 99% or more, and a total yield of anhydrous hydrogen fluoride of 97% or more, and the economic benefit is significantly improved compared with the existing process.

[0006] The specific technical solutions are as follows: In a first aspect, the present application provides a hydrogen fluoride preparation device using a circulating molecular recognition complex system, comprising a self-filtering inclined surface reactor, a dryer and a damping type thermal decomposition reactor connected in sequence; The self-filtering inclined surface reactor integrates complexation reaction, in-situ filtration and crosslinking reaction functions, and comprises a complex reaction-filtering zone and a crosslinking reaction zone; the bottom surface of the complex reaction-filtering zone is an inclined surface gradually decreasing from the center to the edge, and one or more primary complex discharge ports connected to the crosslinking reaction zone are arranged at the edge of the bottom surface of the complex reaction-filtering zone; an axial filter is arranged along the central axis of the complex reaction-filtering zone; the side surface of the axial filter is a liquid inlet, and the bottom is provided with a filtrate outlet; a plurality of stirrers are uniformly distributed around the axial filter in the complex reaction-filtering zone; the crosslinking reaction zone is a static mixing reaction channel with a length-diameter ratio of 5-200:1, preferably 10-50:1; The dryer is connected to the crosslinking reaction zone and is used to dry the solid complex whose crosslinking is completed in the crosslinking reaction zone; The damping type thermal decomposition reactor is used to fluidize and thermally decompose the solid complex dried by the dryer under stable pressure, and discharge the gas containing hydrogen fluoride and the molecular recognition complex system; the molecular recognition complex system discharged by the damping type thermal decomposition reactor is recycled for the complex reaction-filtering zone.

[0007] The complexation reaction-filtering zone is in-situ filtering of the primary complex obtained after the complexation reaction for a certain residence time, and the primary complex obtained by filtering is sent to the cross-linking reaction zone for cross-linking reaction, and the stable network structure complex is obtained after the cross-linking reaction is completed.

[0008] The complexation reaction-filtering zone has a macroscopic geometric feature of high center and low periphery, which is beneficial to the flow and collection of solid materials to the periphery under the action of gravity. The primary complex generated by the complexation reaction can be naturally slid and enriched along the slope under the action of gravity, and one or more primary complex discharge ports are arranged at the periphery of the slope. On the one hand, it is convenient for the remaining fluosilicic acid solution to continue to undergo complexation reaction, and on the other hand, the primary complex is naturally slid to separate solid and liquid to improve the separation efficiency. The included angle between the slope and the horizontal direction is 30°-95°, preferably 45°-80°.

[0009] The axial filter adopts a filter core, which can be a sintered metal, a ceramic membrane or a multi-layer filter screen with a filtering function.

[0010] The number of stirrers is an even number, such as 2, 4, 6, 8, etc. During the complexation reaction, the flow field formed by the stirrers and the flow field of the slope form a composite flow field, which is beneficial to eliminate flow dead zones, strengthen mass transfer and reaction uniformity, and improve the complexation reaction efficiency and filtering efficiency.

[0011] When the primary complex settles along the slope under the action of gravity and moves to the periphery, the area close to the axial filter maintains moderate turbulence due to the tangential flow formed by stirring, so that fine primary complex particles are difficult to stably deposit on the surface of the axial filter, thereby maintaining high throughput filtering. The slope structure can make most of the solids enriched in the peripheral area, reducing the solid load directly borne by the filter, and the lateral stirring forms precise fluid management locally, realizing the cooperative separation mechanism of overall settling and local anti-blocking.

[0012] The stirring speed of the stirrers is 50-500 rpm, preferably 80-200 rpm.

[0013] The stirrers can be provided with one or more layers of stirring paddles, and the stirring paddles can be the same or different, such as straight-blade paddles, curved-blade paddles, disc paddles, spiral paddles, inclined-blade paddles, anchor paddles, frame paddles, etc.

[0014] The height-diameter ratio of the complexation reaction-filtering zone is 1-10:1, preferably 2-6:1.

[0015] The cross-linking reaction zone adopts a static mixing reaction channel with high length-diameter ratio to ensure that the material obtains accurate and uniform residence time, and the inside of the static mixing reaction channel can be provided with static mixing elements, perforated baffles or packed bed structures. Here, the static mixing reaction channel with high length-diameter ratio provides the material with constant and controllable residence time, and by accurately designing the pipe length and pipe diameter, the reaction degree of the cross-linking reaction can be accurately controlled.

[0016] The dryer can be any one of a spray dryer, a fluidized bed dryer, a belt dryer, a compartment dryer, a vacuum rake dryer, a double-cone rotary dryer, etc.

[0017] The dryer can reduce the water content of the solid complex material to below 0.5 wt%.

[0018] The damping type thermal decomposition reactor comprises a thermal decomposition chamber. The top of the thermal decomposition chamber is provided with a decomposition gas outlet.

[0019] The top of the thermal decomposition chamber is connected to a damping type pressure stabilizing system. The damping type pressure stabilizing system is a gas circulation pressure stabilizing system based on the damping principle, comprising a closed gas circulation loop.

[0020] The damping type pressure stabilizing system comprises an exhaust one-way valve, a damping plate, a gas exhaust pipe, a gas return pipe, a pressure stabilizing cavity and a return gas one-way valve. The exhaust one-way valve is located at the decomposition gas outlet and is connected to the gas exhaust pipe and the gas return pipe. The damping plate is arranged in the gas exhaust pipe. The gas return pipe is connected to the return gas one-way valve through the pressure stabilizing cavity, and the return gas one-way valve is connected to the thermal decomposition chamber. The thermal decomposition chamber, the exhaust one-way valve, the gas return pipe, the pressure stabilizing cavity and the return gas one-way valve form the gas circulation loop. The exhaust one-way valve can guide the original decomposition gas with pressure fluctuation into the damping type pressure stabilizing system.

[0021] The pressure stabilizing principle of the damping type pressure stabilizing system is that the high-speed and large-amplitude pressure fluctuation energy of the upstream exhaust gas is first preliminarily dissipated and limited in amplitude by the throttling characteristics of the damping plate, and then the preliminarily processed gas flow is circulated and returned to the pressure stabilizing cavity directly connected thereto, so as to buffer and absorb the gas pressure through the internal volume, real-time attenuate the pressure pulsation of the gas flow, and maintain the pressure stability of the overall return.

[0022] The damping plate is a hole plate with a specific hole diameter, and its main function is to preliminarily straighten and dissipate the kinetic energy of the high-speed and turbulent incoming flow, and to break large-scale vortex flow to stabilize the pressure. The damping plate can have two levels, three levels or even more. The ratio of the hole diameter d of the damping plate to the nominal inner diameter D of the installation pipeline is β, and 0.20 ≤ β ≤ 0.80.

[0023] The pressure stabilizing cavity is a buffer cavity that can contain gas. After the gas is stabilized by the damping, part of the gas is exhausted, and the remaining gas is returned to the pressure stabilizing cavity to complete the storage and release of pressure energy and realize the pressure stabilizing function of the system.

[0024] The reflux gas check valve allows the stable gas contained in the pressure stabilizing chamber to flow back to the upper space of the pyrolysis chamber, allowing gas to flow back from the pressure stabilizing chamber to the pyrolysis chamber in only one direction. In this way, when the pressure fluctuates in the pyrolysis chamber due to the unstable decomposition rate of the decomposition gas, the damping pressure stabilizing system can stabilize the pressure of the exhaust gas entering the subsequent unit and keep the operating pressure of the pyrolysis chamber stable, thereby ensuring the stable operation of the complex decomposition process.

[0025] By adjusting the damping plate aperture, the pressure stabilizing chamber volume, and the return pipe size, it can be flexibly adapted to gas sources of different scales, flow rates, and pressure fluctuation characteristics.

[0026] The pyrolysis chamber has a solid complex inlet in the upper part, a carrier gas inlet in the lower part, and a molecular recognition complexing system outlet at the bottom. The molecular recognition complexing system outlet connects to the complexation reaction-filtration zone.

[0027] The interior of the pyrolysis chamber, from top to bottom, includes a gas-liquid separation component, a gas-liquid separation component support plate, a first filter plate, and a second filter plate.

[0028] The solid complex inlet and the carrier gas inlet are located between the first and second filter plates. The outlet for the molecular recognition complex system is located below the second filter plate.

[0029] The gas-liquid separation component is located directly below the damped pressure stabilization system. It can typically be composed of one or more structures such as a high-efficiency wire mesh demister, a cyclone separator, or a packed coalescing bed. It is mainly used to capture and condense liquid complexing agent components such as droplets and mists entrained in the rising gas flow, causing them to coalesce and grow, and then be efficiently separated from the gas phase.

[0030] The gas-liquid separation component support plate is located below the gas-liquid separation component and is used to support the gas-liquid separation component. It is a grid plate or beam support structure with a high opening ratio. Its main function is to firmly support the gas-liquid separation component above and ensure its structural stability under the impact of airflow.

[0031] The first filter plate is located below the gas-liquid separation component support plate and above the main thermal decomposition reaction zone. The first filter plate includes at least one filter functional layer, which is a plate-shaped or membrane-shaped component with a microporous structure to allow fluid to pass through and retain target substances. Its main function is to perform preliminary solid-state filtration on the rising, untreated pyrolysis gas, intercepting and blocking fine particles and solid entrainments generated by the pyrolysis bed and floating with the airflow. The filter functional layer can generally be made of at least one of porous metal plates, sintered metal mesh, polymer filter membranes, ceramic filter plates, and non-woven filter felts.

[0032] A carrier gas is introduced into the lower part of the pyrolysis chamber. This serves two purposes: firstly, to achieve a boiling-like flow state of the gas-liquid-solid three-phase system within the chamber, which facilitates temperature equilibrium and allows the complex to decompose under near-isothermal conditions; secondly, to provide continuous boiling-like fluidization power for the solid complex decomposition process, enabling rapid surface renewal and improving decomposition efficiency; and thirdly, the introduction of the carrier gas can instantaneously carry away the decomposition gas, creating a certain flow rate that provides conditions for pressure control in the pressure stabilization chamber, ensuring stable and controllable operating pressure during the pyrolysis process. The carrier gas can generally be selected from, but is not limited to, high-purity nitrogen (N2) and high-purity argon. Inert protective gases commonly used in industry, such as Ar and high-purity helium (He), are used. The carrier gas flow rate must consider both the optimal fluidization gas velocity within the reactor and the need to ensure the pressure stabilization function of the damped pressure stabilization system at the top of the pyrolysis reactor. Therefore, the carrier gas velocity is 0.65~1.82 m / s. Here, the lower limit of the carrier gas flow rate refers to the minimum gas velocity that the pressure stabilization chamber can stably control while the solid complex particles exhibit suspension and fluid characteristics within the pyrolysis reactor. The upper limit of the carrier gas flow rate refers to the final velocity that the solid complex particles can fall uniformly within the pyrolysis reactor while the pressure stabilization chamber can stably control.

[0033] The second filter plate is used to intercept and filter solid complexed materials, with a filter resolution of 5μm to 20μm. Below the second filter plate in the pyrolysis chamber is a liquid storage area with an outlet for the molecular recognition complexing system.

[0034] The hydrogen fluoride preparation apparatus employing a molecular recognition complexation system further includes a hydrogen fluoride separation tower and a hydrogen fluoride purification tower; the damped thermal decomposition reactor, 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 damped thermal decomposition reactor 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.

[0035] The hydrogen fluoride preparation apparatus employing a molecular recognition complexation system 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-filtration zone are connected sequentially. The hydrogen fluoride separation tower is connected to the fluorosilicic acid raw material tank. The fluorosilicic acid raw material tank receives fluorosilicic acid raw material and silicon tetrafluoride gas (originating from the hydrogen fluoride separation tower), and the silicon tetrafluoride gas is hydrolyzed to generate silicon dioxide and fluorosilicic acid. The solid-liquid separation device separates 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.

[0036] Secondly, the present invention provides the application of the hydrogen fluoride preparation apparatus using a molecular recognition complexation system cycle as described in the first aspect for the preparation of hydrogen fluoride.

[0037] Thirdly, the present invention provides a method for preparing hydrogen fluoride using a molecular recognition complexation system in a cyclic manner, employing the hydrogen fluoride preparation apparatus for a cyclic manner using a molecular recognition complexation system as described in the first aspect. The method for preparing hydrogen fluoride using a molecular recognition complexation system includes: Fluorosilicic acid solution and molecular recognition complexation system enter a self-filtering inclined reactor. First, a complexation reaction is carried out in the complexation reaction-filtration zone, and in-situ filtration is completed. The filtrate is discharged from the filtrate outlet at the bottom of the axial filter. The primary complex generated by the complexation reaction enters the cross-linking reaction zone through the primary complex outlet on the inclined plane to carry out the cross-linking reaction and 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 damped pyrolysis reactor where it undergoes fluidized thermal decomposition under stable pressure, releasing hydrogen fluoride gas, silicon tetrafluoride gas, and the molecular recognition complex system. The molecular recognition complex system discharged from the damped pyrolysis reactor is recycled for use in the complexation reaction-filtration zone.

[0038] 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 complexation reaction, as the complexation reaction occurs, the fluorosilicic acid molecules in the fluorosilicic acid raw material react rapidly with the molecular recognition complexation system (crosslinking agent, complexing agent, and additives) to form a solid primary complex. When the remaining liquid contains only unreacted water and trace amounts of the molecular recognition complexation system from the fluorosilicic acid raw material, the bottom filtrate outlet of the axial filter can be opened to discharge the remaining oil. The primary complex is then introduced into the crosslinking reaction zone along the slope to undergo a crosslinking reaction and form a stable network structure complex. The opening status and opening amplitude of the bottom filtrate outlet of the axial filter are adjustable, allowing the complexation reaction-filtration zone to operate continuously or intermittently, or allowing the complexation reaction and filtration within the complexation reaction-filtration zone to proceed simultaneously or sequentially.

[0039] 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.

[0040] 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%.

[0041] 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.

[0042] 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%.

[0043] 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%.

[0044] 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.

[0045] 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.

[0046] The pressure for the complexation reaction is preferably atmospheric pressure to 1.0 MPa, and more preferably atmospheric pressure to 0.15 MPa.

[0047] 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.

[0048] The preferred temperature for the crosslinking reaction is 6~85℃, for example 10℃, and more preferably 15~60℃.

[0049] The pressure for the crosslinking reaction is preferably atmospheric pressure to 1.0 MPa, and more preferably atmospheric pressure to 0.15 MPa.

[0050] 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.

[0051] The cross-linking reaction time is preferably 1 to 20 minutes, and more preferably 2 to 10 minutes.

[0052] The thermal decomposition temperature is preferably 120~450℃, more preferably 150~350℃, such as 320℃.

[0053] The pressure for thermal decomposition is preferably 0.1~1.0 MPa, more preferably 0.12~0.50 MPa, such as 0.20 MPa.

[0054] 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.

[0055] Those skilled in the art should understand that hydrogen fluoride is the most crucial basic raw material in inorganic fluorine chemicals, often referred to as the lifeblood of the fluorine industry. Almost all industrial organic and inorganic fluorides are produced by treating fluorite with sulfuric acid to obtain hydrogen fluoride. However, the reliance on high-grade fluorite, the presence of byproduct waste, and high energy consumption are just some of the problems that urgently require updates and replacements. Among new hydrogen fluoride preparation processes, the production of anhydrous hydrogen fluoride from fluorosilicic acid (a byproduct of the phosphate fertilizer industry) is a representative of the circular economy and has significant utilization value. However, another major problem is that the mainstream direct thermal decomposition process using sulfuric acid generates large amounts of dilute sulfuric acid, leading to significant environmental pressure, which also urgently needs to be updated and replaced. To this end, researchers in the hydrogen fluoride preparation industry have successively developed new processes such as fluoride conversion and chemical extraction. However, these all suffer from industrial conversion bottlenecks such as high energy consumption, low fluorine recovery rate, low extraction efficiency, and severe extractant loss. Therefore, there is an urgent need to develop a new hydrogen fluoride preparation process that is both economically and environmentally efficient and industrially feasible. This invention develops a hydrogen fluoride preparation device and method using a molecular recognition complexing agent cycle. This method eliminates the use of concentrated sulfuric acid, thus avoiding the generation of large amounts of dilute sulfuric acid and environmental problems. At the same time, this method has ultra-high selectivity and affinity for fluorosilicic acid molecules, and by using a highly efficient preparation device, it can achieve a high fluoride extraction rate and maximize the value of fluorine resources.

[0056] Compared with the prior art, the beneficial effects of this invention are as follows: This invention first employs a molecular recognition complexation system capable of precisely identifying fluorosilicic acid to selectively complex fluorosilicic acid molecules in a self-filtering inclined plane reactor, preparing a complex. Then, through a specially designed damped thermal decomposition reactor, the complex is thermally decomposed to obtain pressure-stable hydrogen fluoride gas, and the hydrogen fluoride is distilled to obtain anhydrous hydrogen fluoride. Compared with traditional methods such as direct sulfuric acid decomposition, ammonium fluoride method, and extraction method, this invention has significant advantages. On the one hand, it eliminates the use of concentrated sulfuric acid, resulting in significant environmental benefits. On the other hand, based on the excellent circulation performance of the molecular recognition complexation system, it has strong industrial feasibility. The entire process is safe, stable, and controllable, and has good market application prospects. Attached Figure Description

[0057] Figure 1 This is a schematic diagram of a hydrogen fluoride preparation device using a molecular recognition complexation system cyclical process according to the present invention. Detailed Implementation

[0058] 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.

[0059] Example 1: See Figure 1 A hydrogen fluoride preparation apparatus employing a molecular recognition complexation system for circulation includes, in sequence, a fluorosilicic acid raw material tank 3, a fluorosilicic acid discharge pump 5, a solid-liquid separation device 6, a self-filtering inclined reactor 9, a dryer 17, a damped thermal decomposition reactor 20, a hydrogen fluoride separation tower 35, and a hydrogen fluoride purification tower 37. The hydrogen fluoride separation tower 35 is also connected to the fluorosilicic acid raw material tank 3.

[0060] The self-filtering inclined plane reactor 9 integrates complexation reaction, in-situ filtration, and cross-linking reaction functions, and includes a complexation reaction-filtration zone 12 and a cross-linking reaction zone 13. A solid-liquid separation device 6 is connected to the complexation reaction-filtration zone 12. The bottom surface of the complexation reaction-filtration zone 12 is an inclined plane that gradually decreases from the center to the edge. One or more primary complex discharge ports connecting to the cross-linking reaction zone 13 are provided at the edge of the bottom surface of the complexation reaction-filtration zone 12. An axial filter 14 is provided along the central axis of the complexation reaction-filtration zone 12. The side of the axial filter 14 is a liquid inlet, and the bottom is a filtrate outlet. Multiple stirrers are evenly distributed around the axial filter 14 within the complexation reaction-filtration zone 12. Each stirrer includes a stirring paddle 16 and a motor 15 connected to the stirring paddle 16 and used to drive the stirring paddle 16 to rotate. The cross-linking reaction zone 13 is a static mixing reaction channel with a high aspect ratio.

[0061] Dryer 17 is connected to crosslinking reaction zone 13 and is used to dry the solid complex that has completed crosslinking in crosslinking reaction zone 13.

[0062] The damped pyrolysis reactor 20 is used to fluidize the solid complexes dried in the pyrolysis dryer 17 under stable pressure and to discharge gases and molecularly recognized complex systems. The molecularly recognized complex system discharged from the damped pyrolysis reactor 20 is recycled to the complexation reaction-filtration zone 12.

[0063] The damped pyrolysis reactor 20 includes a pyrolysis chamber. A decomposition gas outlet is located at the top of the pyrolysis chamber. A damped pressure stabilization system 21 is connected to the top of the pyrolysis chamber. The damped pressure stabilization system 21 includes an exhaust check valve 22, a primary damping plate 23, a secondary damping plate 24, a gas exhaust pipe 25, a gas return pipe 26, a pressure stabilizing chamber 27, and a return gas check valve 28. The exhaust check valve 22 is located at the decomposition gas outlet and connects the gas exhaust pipe 25 and the gas return pipe 26. The primary damping plate 23 and the secondary damping plate 24 are sequentially arranged within the gas exhaust pipe 25 along the gas flow direction. The gas return pipe 26 is connected to the return gas check valve 28 through the pressure stabilizing chamber 27, and the return gas check valve 28 connects to the pyrolysis chamber. The pyrolysis chamber, exhaust check valve 22, gas return pipe 26, pressure stabilizing chamber 27, and return gas check valve 28 constitute a gas circulation loop. The primary damping plate 23 and the secondary damping plate 24 are perforated plates with specific apertures.

[0064] The pyrolysis chamber has a solid complex inlet 18 in the upper part, a carrier gas inlet 19 in the lower part, and a molecular recognition complex system outlet 33 at the bottom. The molecular recognition complex system outlet 33 is connected to the complexation reaction-filtration zone 12 via a pump 34. The interior of the pyrolysis chamber, from top to bottom, includes a gas-liquid separation component 29, a gas-liquid separation component support plate 30, a first filter plate 311, and a second filter plate 312. The solid complex inlet 18 and the carrier gas inlet 19 are located between the first filter plate 311 and the second filter plate 312. The molecular recognition complex system outlet 33 is located below the second filter plate 312.

[0065] The hydrogen fluoride preparation apparatus described above, which uses a molecular recognition complexation system for recycling, can be used for hydrogen fluoride preparation.

[0066] A method for preparing hydrogen fluoride using a molecular recognition complexation system cycle, utilizing the aforementioned hydrogen fluoride preparation apparatus using a molecular recognition complexation system cycle, includes: 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 complexing system 8 enter a self-filtering inclined reactor 9. The complexing reaction and in-situ filtration are carried out first in the complexing reaction-filtration zone 12 under stirring. The filtrate 10 is discharged from the bottom filtrate outlet of the axial filter 14. The primary complex generated by the complexing reaction passes through the inclined surface and the primary complex discharge port into the cross-linking reaction zone 13 for cross-linking reaction to obtain a stable network structure complex 11. The molecular recognition complexing system contains a complexing agent and a cross-linking agent.

[0067] After being dried by dryer 17, the stable network structure complex 11 enters the damped pyrolysis reactor 20, where it undergoes fluidized pyrolysis under stable pressure, releasing hydrogen fluoride gas, silicon tetrafluoride gas, and the molecular recognition complex system. Specifically, carrier gas is introduced into the carrier gas inlet 19 of the pyrolysis chamber. This serves two purposes: firstly, to provide continuous power for the fluidization of the pyrolysis chamber, constantly renewing the surface of the complex and increasing the decomposition rate; and secondly, to instantly carry away the decomposition gas, forming a stable flow rate, making the pyrolysis process more stable and controllable. The mixed gas 32 containing carrier gas, silicon tetrafluoride, and hydrogen fluoride gas obtained from the damped pyrolysis reactor 20 is discharged from the top. The resulting molecular recognition complex system is filtered by the second filter plate 312 and discharged from the bottom molecular recognition complex system outlet 33. It is then extracted by the extraction pump 34 and recycled back to the complexation reaction-filtration zone 12. The mixed gas 32 is first separated by distillation in the hydrogen fluoride separation tower 35. At the top of the tower, silicon tetrafluoride gas 2 with or without carrier gas is obtained and is recycled to the fluorosilicic acid raw material tank 3 for further concentration. The crude hydrogen fluoride 36 obtained at the bottom of the tower enters the hydrogen fluoride refining tower 37 for purification and refining, and finally anhydrous hydrogen fluoride product 38 is obtained.

[0068] Example 2: Hydrogen fluoride products were prepared using the hydrogen fluoride preparation apparatus and method employing molecular recognition complexing agent cycling as described in Example 1.

[0069] The fluorosilicic acid raw materials contain 0.24% and 18.98% fluorosilicic acid by mass concentration, respectively. The 0.24% concentration raw material is prepared by diluting the 18.98% concentration raw material.

[0070] The molecular recognition complexation systems are numbered 1100 and 1200, respectively, and their components and contents are shown in Table 1.

[0071] Table 1. Composition of the molecular recognition complex system The preparation method specifically includes: (1) In a filter-type inclined reactor, a molecular recognition complexation system is used to accurately capture, highly selectively complex, filter in situ, and rapidly crosslink fluorosilicic acid molecules in the fluorosilicic acid solution to generate a stable complex; (2) The complex is then dried and introduced into a damped thermal decomposition reactor with an integrated damped pressure stabilization system. Under the fluidization power provided by the carrier gas, the complex is thermally decomposed to obtain a pressure-stable hydrogen fluoride gas, and then anhydrous hydrogen fluoride product is obtained by hydrogen fluoride distillation.

[0072] The complexation reaction conditions are as follows: temperature 15℃, pressure at atmospheric pressure; molar ratio of fluorosilicic acid to complexing agent 2.25:1; complexation time 15 min; The crosslinking reaction conditions are as follows: temperature 25℃, pressure at atmospheric pressure; crosslinking reaction time 8 min; Self-filtering inclined plane reactor: The angle between the inclined plane and the horizontal direction is 45°; Four evenly arranged agitators are installed on the side of the axial filter, and the agitator speed is 180 rpm; The height-to-diameter ratio of the complexation reaction-filtration zone is 3:1; The aspect ratio of the cross-linking reaction zone is 30:1; The thermal decomposition conditions for the complex were: temperature 219.0~220.7℃; pressure 0.18~0.19MPa; and residence time 30min. In a damped pyrolysis reactor, the ratio of the aperture d of the primary damping plate to the nominal inner diameter D of the pipe to which it is installed is 0.60, and the ratio of the aperture d of the secondary damping plate to the nominal inner diameter D of the pipe to which it is installed is 0.35. The carrier gas is high-purity nitrogen (N2) (purity >99.999%), and the gas flow rate is 0.89~1.15m / s.

[0073] After processing using the above methods, the exhaust gas from the top of the damped thermal decomposition reactor is further purified by distillation to obtain anhydrous hydrogen fluoride of superior grade (key indicators include 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 hydrogen fluoride preparation apparatus and method with molecular recognition complexing agent cycling described in Example 1. The specific preparation method is similar to that in Example 2.

[0075] The complexation reaction conditions were as follows: temperature 21℃, pressure at atmospheric pressure; molar ratio of fluorosilicic acid to complexing agent 2.22:1; complexation time 12 min. The crosslinking reaction conditions are as follows: temperature 29℃, pressure at atmospheric pressure; crosslinking reaction time 6 min; Self-filtering inclined plane reactor: The angle between the inclined plane and the horizontal direction is 75°; Six evenly arranged agitators are installed on the side of the axial filter, with the agitator speed being 150 rpm; The reactor's height-to-diameter ratio is 4:1; The aspect ratio of the cross-linking reaction zone is 25:1; The thermal decomposition conditions for the complex were: temperature 219.3~220.4℃; pressure 0.18~0.19MPa; and residence time 30min. In a damped pyrolysis reactor, the ratio of the aperture d of the primary damping plate to the nominal inner diameter D of the pipe to which it is installed is 0.60, and the ratio of the aperture d of the secondary damping plate to the nominal inner diameter D of the pipe to which it is installed is 0.35. The carrier gas is high-purity nitrogen (N2) (purity >99.999%), and the gas flow rate is 0.94~1.38m / s.

[0076] After processing using the above methods, the exhaust gas from the top of the damped thermal decomposition reactor is further purified by distillation to obtain anhydrous hydrogen fluoride of superior grade (key indicators include 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.

[0077] Example 4: Hydrogen fluoride products were prepared using the hydrogen fluoride preparation apparatus and method with molecular recognition complexing agent cycling described in Example 1. The specific preparation method is similar to that in Example 2.

[0078] The complexation reaction conditions are as follows: temperature 32℃, pressure at atmospheric pressure; molar ratio of fluorosilicic acid to complexing agent 2.20:1; complexation time 10 min. The crosslinking reaction conditions are as follows: temperature 41℃, pressure at atmospheric pressure; crosslinking reaction time 5.5 min; Self-filtering inclined plane reactor: The angle between the inclined plane and the horizontal direction is 60°; Four evenly arranged agitators are installed on the side of the axial filter, and the agitator speed is 220 rpm; The reactor's height-to-diameter ratio is 3:1; The aspect ratio of the cross-linking reaction zone is 25:1; The thermal decomposition conditions for the complex were: temperature 219.7~221.3℃; pressure 0.18~0.19MPa; and residence time 32min. In a damped pyrolysis reactor, the ratio of the aperture d of the primary damping plate to the nominal inner diameter D of the pipe to which it is installed is 0.45, and the ratio of the aperture d of the secondary damping plate to the nominal inner diameter D of the pipe to which it is installed is 0.22. The carrier gas is high-purity nitrogen (N2) (purity >99.999%), and the gas flow rate is 0.72~1.46m / s.

[0079] After processing using the above methods, the exhaust gas from the top of the damped thermal decomposition reactor is further purified by distillation to obtain anhydrous hydrogen fluoride of superior grade (key indicators include 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.

[0080] Table 2 As can be seen from Examples 2 to 4 of this invention, the hydrogen fluoride preparation device and method using a molecular recognition complexing agent circulation, the molecular recognition complexing agent and the self-filtering inclined reactor structure can effectively ensure that the complexation rate of fluorosilicic acid reaches more than 99.8%. The decomposition of the complexation product is carried out using a damped thermal decomposition reactor with a special structure, which ensures the stability of the decomposition process pressure and achieves a fluorosilicic acid decomposition rate of more than 99%, thereby increasing the total anhydrous hydrogen fluoride yield to more than 97%, and significantly improving economic benefits.

[0081] 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. A device for preparing hydrogen fluoride using a molecular recognition complexation system, characterized in that, It includes a self-filtering inclined plane reactor, a dryer, and a damped pyrolysis reactor connected in sequence; The self-filtering inclined plane reactor integrates complexation reaction, in-situ filtration, and cross-linking reaction functions, including a complexation reaction-filtration zone and a cross-linking reaction zone. The bottom surface of the complexation reaction-filtration zone is an inclined plane that gradually decreases from the center to the edge. One or more primary complex discharge ports connecting to the cross-linking reaction zone are provided at the edge of the bottom surface of the complexation reaction-filtration zone. An axial filter is provided along the central axis of the complexation reaction-filtration zone. The side of the axial filter is the liquid inlet, and the bottom is the filtrate outlet. Multiple stirrers are evenly distributed around the axial filter in the complexation reaction-filtration zone. The cross-linking reaction zone is a static mixing reaction channel with a length-to-diameter ratio of 5~200:1, preferably 10~50:

1. The dryer is connected to the cross-linking reaction zone and is used to dry the solid complexes that have completed cross-linking in the cross-linking reaction zone. Damped pyrolysis reactors are used to dry solid complexes in a fluidized pyrolysis dryer under stable pressure and to discharge gases containing hydrogen fluoride and molecular recognition complex systems. The molecular recognition complexation system discharged from the damped pyrolysis reactor is recycled for complexation reaction-filtration zone.

2. The hydrogen fluoride preparation apparatus employing a molecular recognition complexation system for circulation according to claim 1, characterized in that, The angle between the inclined plane and the horizontal direction is 30°~95°, preferably 45°~80°.

3. The hydrogen fluoride preparation apparatus employing a molecular recognition complexation system for circulation according to claim 1, characterized in that, The number of stirrers is even; The stirring speed is 50~500rpm, preferably 80~200rpm; The height-to-diameter ratio of the complexation reaction-filtration zone is 1~10:1, preferably 2~6:

1.

4. The hydrogen fluoride preparation apparatus employing a molecular recognition complexation system for circulation according to claim 1, characterized in that, The damped pyrolysis reactor includes a pyrolysis chamber; the top of the pyrolysis chamber is provided with a decomposition gas outlet. A damped voltage stabilizing system is connected to the top of the pyrolysis chamber; The damped pressure stabilizing system includes an exhaust check valve, a damping plate, a gas exhaust pipe, a gas return pipe, a pressure stabilizing chamber, and a return gas check valve. The exhaust check valve is located at the decomposition gas outlet and connects the gas exhaust pipe and the gas return pipe. The damping plate is located inside the gas exhaust pipe. The gas return pipe is connected to the return gas check valve through the pressure stabilizing chamber, and the return gas check valve is connected to the pyrolysis chamber.

5. The hydrogen fluoride preparation apparatus employing a molecular recognition complexation system for circulation according to claim 4, characterized in that, The ratio of the damping plate aperture d to the nominal inner diameter D of the pipe to which it is installed is β, where 0.20 ≤ β ≤ 0.

80.

6. The hydrogen fluoride preparation apparatus employing a molecular recognition complexation system for circulation according to claim 4, characterized in that, The upper part of the pyrolysis chamber is equipped with a solid complex inlet, the lower part with a carrier gas inlet, and the bottom with a molecular recognition complexation system outlet; the molecular recognition complexation system outlet is connected to the complexation reaction-filtration zone; The interior of the pyrolysis chamber, from top to bottom, includes a gas-liquid separation component, a gas-liquid separation component support plate, a first filter plate, and a second filter plate. The solid complex inlet and the carrier gas inlet are located between the first filter plate and the second filter plate; the molecular recognition complex system outlet is located below the second filter plate.

7. The hydrogen fluoride preparation apparatus employing a molecular recognition complexation system for circulation according to claim 1, characterized in that, The hydrogen fluoride preparation device using a molecular recognition complexation system also includes a hydrogen fluoride separation tower and a hydrogen fluoride purification tower; the damped thermal decomposition reactor, the hydrogen fluoride separation tower, and the hydrogen fluoride purification tower are connected in sequence.

8. The hydrogen fluoride preparation apparatus employing a molecular recognition complexation system for circulation according to claim 7, characterized in that, The hydrogen fluoride preparation device using a molecular recognition complexation system 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-filtration zone are connected in sequence; the hydrogen fluoride separation tower is connected to the fluorosilicic acid raw material tank.

9. The application of the hydrogen fluoride preparation apparatus using a molecular recognition complexation system according to any one of claims 1 to 8 for the preparation of hydrogen fluoride.

10. A method for preparing hydrogen fluoride using a molecular recognition complexation system, characterized in that, The apparatus for preparing hydrogen fluoride using a molecular recognition complexation system as described in any one of claims 1 to 8; The method for preparing hydrogen fluoride using a molecular recognition complexation system includes: Fluorosilicic acid solution and molecular recognition complexation system enter a self-filtering inclined reactor. First, a complexation reaction is carried out in the complexation reaction-filtration zone, and in-situ filtration is completed. The filtrate is discharged from the filtrate outlet at the bottom of the axial filter. The primary complex generated by the complexation reaction enters the cross-linking reaction zone through the primary complex outlet on the inclined plane to carry out the cross-linking reaction and 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 damped pyrolysis reactor for fluidized pyrolysis under stable pressure, and discharges hydrogen fluoride gas, silicon tetrafluoride gas and molecular recognition complex system. The molecular recognition complexation system discharged from the damped pyrolysis reactor is recycled for complexation reaction-filtration zone.

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