Preparation method of sulfuryl fluoride chloride

Abstract

The invention belongs to the technical field of chemical engineering and fine fluorine chemical synthesis, and particularly relates to a preparation method of sulfuryl fluoride chloride. According to the preparation method, through the synergistic effect of a gas-liquid reaction system and a closed-loop circulation system, a tertiary amine hydrofluoric acid adduct (such as Et3N.nHF, n = 2-6) is used as a fluorinating reagent, sulfuryl fluoride chloride is generated through a rapid cross-flow reaction in excessive sulfuryl chloride (SO2Cl2) under the conditions that the temperature is 65-100 DEG C and the pressure is 0.5-2.0 MPa, and a liquid-phase byproduct tertiary amine hydrochloride hydrogen fluoride adduct (such as Et3N.HCl. (n-1) HF) is used for preparing the sulfuryl fluoride chloride. Supplementing hydrogen fluoride to regenerate the catalyst and recycling; and after a gas-phase product is pressurized, rectified and purified by a light component removal tower and a heavy component removal tower, totally returning a light component (Cl2 / SO2) and a heavy component (SO2Cl2) to a synthesis system for recycling. According to the method, the reaction temperature, the reaction pressure, the liquid phase dispersion degree and the contact time are accurately controlled, so that the reaction product generates SO2FCl with high selectivity, and the byproduct (R3N.HCl. (n-1) HF) is kept in a liquid phase, so that the reaction can be continuously carried out, and conditions are created for subsequent treatment.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of chemical engineering and fine fluorine chemical synthesis, and particularly relates to a preparation method of sulfuryl fluoride chloride. BACKGROUND

[0002] As a new type of hybrid compound of the sulfuryl halide family, sulfuryl fluoride chloride (SO2FCl) has a unique chemical dual-functionality due to the F / Cl dual-halogen system existing in the molecule. Compared with traditional sulfuryl fluoride (SO2F2) and sulfuryl chloride (SO2Cl2), this compound not only inherits the high thermal stability (decomposition temperature > 300℃) and material compatibility of sulfuryl fluoride, but also significantly improves the reaction activity through the electronic effect of Cl atoms, making it a highly potential fluorine-chlorine bifunctional reagent in the field of fine fluorine chemistry.

[0003] In the dimension of industrial application, sulfuryl fluoride chloride exhibits three technical values: (1) as a key precursor of lithium bis(fluorosulfonyl)imide (LiFSI) electrolyte, its F / Cl selective replacement characteristics can precisely regulate the fluorination degree of the molecular skeleton; (2) as a modular structural unit in the synthesis of new fluorine-containing pesticides, the F / Cl dual-functional group transfer in a single step can reduce the 2-3 intermediate synthesis steps in traditional processes; (3) as a modified comonomer of fluorine-containing polymers, the steric effect of Cl atoms can increase the glass transition temperature of the polymers by 20-30℃.

[0004] However, the industrialization process of this sulfuryl fluoride chloride compound is severely restricted by the synthesis technical bottleneck. There is no preparation method in the existing public technology that can meet the requirements of industrial continuous production, and the following core defects exist:

[0005] I. Irreversible consumption mechanism of catalyst

[0006] The stoichiometric consumption problem exists in the existing catalytic system, which is specifically manifested as:

[0007] In the liquid-phase amine catalytic system (such as triethylamine), the by-product HCl forms triethylamine hydrochloride ([Et3NH]Cl) precipitate (Ksp = 4.3 x 10 -4 ) with the catalyst, forcing the reaction system to run intermittently and continuously add catalyst;

[0008] The solid acid catalyst (such as Hβ molecular sieve) is chlorinated in the Cl- containing environment , and the acid strength of the acid site is attenuated from the initial H0 = -8.2 to -5.4 (NH3-TPD characterization), and the half-life of catalytic activity is <72h;

[0009] The difference in gas-solid mass transfer coefficient (kCl=0.38 m / s vs kF=0.22 m / s) in the gas-solid phase process leads to a high corrosion rate of 0.15 mm / a of the equipment, and the catalyst cannot be regenerated in situ.

[0010] II. Contradiction between continuous production and product purity

[0011] The traditional process faces the problem of purity degradation during scale-up, which is specifically manifested as follows:

[0012] The existing rectification process cannot realize F / Cl separation, resulting in SO2F2 impurity content >3000 ppm in the sulfuryl fluoride chlorine product;

[0013] The pipe wall fouling phenomenon caused by the deposition of ammonium salt in continuous production makes the system pressure rise by 0.3 MPa every 48 hours, and the system is forced to stop and clean.

[0014] Referring to the amine catalytic system disclosed in CN114477100A, the technical defects are typical representatives: in the ternary reaction system (SO2 / Cl2 / HF), triethylamine not only participates in the fluorine-chlorine exchange reaction as a catalyst, but also undergoes irreversible acid-base neutralization reaction with the by-product HCl to generate [Et3NH]Cl precipitate. This leads to an exponential decay of the effective concentration of the catalyst (Ct=C0e^(-0.23t)), and a complex solid-liquid separation-catalyst regeneration system must be configured.

[0015] The above technical defects form a vicious cycle: the continuous consumption of the catalyst forces the process to adopt a batch operation, and the batch operation mode further aggravates the problems of by-product accumulation and equipment corrosion. This technical contradiction seriously restricts the large-scale application of sulfuryl fluoride chlorine in strategic emerging fields such as new energy materials and agricultural products.

[0016] In order to solve the above problems, the present application is proposed. SUMMARY

[0017] The present application relates to a method for preparing sulfuryl fluoride chlorine (SO2FCl) based on a tertiary amine catalytic system, which covers catalytic synthesis of fluorinated reagents, optimization of gas-liquid reaction process, closed-loop material circulation system, and by-product resourceization and regeneration technology, and is suitable for efficient and green synthesis of fluorine-containing fine chemicals.

[0018] The method for preparing sulfuryl fluoride chlorine according to the present application comprises: reacting a tertiary amine hydrogen fluoride adduct and sulfuryl chloride at 65-100°C and 0.5-2.0 MPa for 15-120 seconds to obtain sulfuryl fluoride chlorine; wherein the molar ratio of the tertiary amine hydrogen fluoride adduct to sulfuryl chloride is 1:1.0-1.5.

[0019] Alternatively, the preparation method comprises: reacting a tertiary amine hydrogen fluoride adduct, sulfur dioxide and chlorine gas at 65-100℃ and 0.5-2.0MPa for 15-120 seconds to obtain sulfuryl fluoride chloride; wherein the molar ratio of the tertiary amine hydrogen fluoride adduct, sulfur dioxide and chlorine gas is 1:(1.0-1.5):(1.0-1.5).

[0020] Sulfur dioxide and chlorine gas have the same effect as sulfuryl chloride.

[0021] Preferably, the tertiary amine hydrogen fluoride adduct is represented as R3N·nHF, and n is 2-6; more preferably, n is 3-4. Research has found that when n is 2 or less, the tertiary amine hydrogen fluoride adduct is in the form of a low-melting solid at room temperature and normal pressure, and melts into a liquid when the temperature is raised to above 65℃. When n is 3 or more, the adduct is in the form of a liquid at room temperature and normal pressure (or under the conditions of 65-100℃ and 0.5-2.0MPa in the present application). The liquid tertiary amine hydrogen fluoride adduct has the ability to dissolve tertiary amine hydrochloride, so under the reaction conditions of the present application, the liquid tertiary amine hydrogen fluoride adduct can dissolve tertiary amine hydrochloride, avoiding the deposition of the by-product tertiary amine hydrochloride. Tertiary amine hydrochloride is present in the system and will also combine with hydrogen fluoride.

[0022] Preferably, the preparation method further comprises: after the liquid-phase by-product tertiary amine hydrochloride hydrogen fluoride adduct is reacted with hydrogen fluoride, removing hydrogen chloride under reduced pressure or by heating to obtain a tertiary amine hydrogen fluoride adduct for recycling.

[0023] Preferably, the liquid-phase by-product tertiary amine hydrochloride hydrogen fluoride adduct R3N·HCl·(n-1)HF is reacted with hydrogen fluoride to obtain a tertiary amine hydrochloride hydrogen fluoride adduct R3N·HCl·nHF, and n is 2-6.

[0024] Preferably, the sulfuryl fluoride chloride exists in a gas phase product, and the gas phase product is purified to obtain a sulfuryl fluoride chloride product.

[0025] Preferably, the sulfuryl chloride is synthesized from sulfur dioxide and chlorine gas under the catalysis of a tertiary amine.

[0026] Preferably, the tertiary amine in the tertiary amine hydrogen fluoride adduct is selected from C3-C12 aliphatic tertiary amines, i.e. aliphatic tertiary amines with 3-12 carbon atoms; and triethylamine is preferably used.

[0027] Preferably, the reaction is carried out in a gas-liquid cross-flow manner.

[0028] Preferably, the reaction conditions for reacting the liquid-phase by-product tertiary amine hydrochloride hydrogen fluoride adduct with hydrogen fluoride are normal pressure and 40-60℃.

[0029] The above reaction is carried out under pressure conditions of 0.5 to 2.0 MPa to ensure that the gaseous products can be liquefied during cooling. This allows for the gradual removal of evaporated sulfuryl chloride (the task of the heavy removal tower), liquefaction of sulfuryl fluoride, and the removal of sulfur dioxide and chlorine generated from decomposition (the task of the light removal tower).

[0030] The reaction process of this application is as follows:

[0031] Tertiary amine hydrofluoric acid adduct (R3N·nHF) + sulfuryl chloride (SO2Cl2) or (sulfur dioxide and chlorine) → sulfuryl fluoride chloride (SO2FCl) + tertiary amine hydrochloride hydrogen fluoride adduct (R3N·HCl·(n-1)HF) + small amount of by-product gas (may contain sulfur dioxide, chlorine, hydrogen chloride, sulfuryl fluoride);

[0032] Regeneration of fluorinating reagents:

[0033] The tertiary amine hydrochloride hydrogen fluoride adduct R3N·HCl·(n-1)HF + HF → tertiary amine hydrochloride hydrogen fluoride adduct (R3N·HCl·nHF). The value of n is 2 to 6.

[0034] The features of this application are as follows:

[0035] 1. Gas-liquid catalytic reaction system

[0036] (1) Raw materials and catalysts: Unlike the liquid-liquid and gas-gas reaction systems in traditional schemes, this invention is based on a rapid cross-flow reaction method. Liquid tertiary amine hydrofluoric acid adduct (Et3N·nHF) is used as the fluorinating agent. The gaseous and excess sulfuryl chloride (SO2Cl2) undergoes a rapid gas-liquid reaction under pressure (0.5~2.0MPa) to generate sulfuryl fluoride chloride which enters the gas phase. The gas phase products also include excess sulfuryl chloride, hydrogen chloride, sulfur dioxide, and chlorine.

[0037] 2. Precise control of reaction depth:

[0038] This is the core innovation of this invention. The reaction depth is precisely controlled by adjusting the proportions of the reactants, reaction temperature, pressure, and time. The results of this invention demonstrate that, to achieve highly selective production of the target product, thioyl fluoride, thioyl chloride must be maintained in excess.

[0039] Taking Et3N·nHF as an example, under suitable conditions, the following main reaction occurs:

[0040] Et3N·3HF+mSO2Cl2=Et3N·HCl·2HF+SO2FCl↑+(m-1)SO2Cl2; m>1;

[0041] If Et3N·3HF is in excess (w>2), a reaction occurs where the product is mainly sulfuryl fluoride (SO2F2):

[0042] wEt3N·3HF+SO2Cl2=w Et3N·HCl·(3-2 / w)HF+SO2F2↑.

[0043] Furthermore, studies have shown that n in tertiary amine hydrogen fluoride adducts (R3N·nHF) is often greater than 1 (with 3 being the most typical). Therefore, even with excess thioyl chloride, the reaction products can become complex if the reaction depth is not well controlled.

[0044] Et3N·3HF+SO2Cl2=Et3N·HCl·(1+x)HF+xSO2FCl↑+(1-x)SO2F2+xHCl↑;

[0045] 0≤x≤1;

[0046] As x decreases, Et3N·HCl·(1+x)HF gradually turns into a solid, causing scaling on the pipe wall and catalyst loss, thus disrupting the continuity of the reaction.

[0047] The inventive point of this application lies in utilizing the subtle differences in properties and reactivity of R3N·nHF with varying n, and through precise control of reaction temperature, reaction pressure, liquid phase dispersion, and contact time, to achieve highly selective formation of SO2FCl from the reaction product, while the byproduct (R3N·HCl·(n-1)HF) remains in the liquid phase. This allows the reaction to proceed continuously and creates conditions for subsequent processing. In the gaseous product of this application, the volume ratio of SO2FCl is over 90%.

[0048] 3. Dynamic closed-loop regeneration system

[0049] (1) Catalyst regeneration of tertiary amine hydrofluoric acid adduct: For the liquid phase byproduct (Et3N·HCl·(n-1)HF), add hydrogen fluoride to restore the n value to 2-6 (preferably 3-4), reduce the pressure to below 2.0 kPa or remove HCl by heating, and regenerate the catalyst for use in the recycling reaction.

[0050] (2) Product purification and recycling: The gaseous product is purified by a light component removal tower (separating Cl2, SO2, HCl, and SO2F2) and a heavy component removal tower (recovering SO2Cl2), with the final product, sulfuryl fluoride chloride, having a purity >98.0%. The light components (Cl2, SO2, HCl, SO2F2) and the heavy components (SO2Cl2) are returned to the sulfuryl fluoride synthesis chamber as raw materials for recycling. Alternatively, the gas from the light component removal tower is sent for incineration. Detailed Implementation

[0051] The present invention will be described below with reference to specific embodiments, but the implementation of the present invention is not limited thereto. Experimental methods not specifically described in the embodiments generally use conventional conditions and conditions described in the manual, or conditions recommended by the manufacturer. The general equipment, materials, reagents, etc., used are all commercially available unless otherwise specified. The raw materials used in the following embodiments and comparative examples are all commercially available.

[0052] This application discloses a method for the lossless preparation of sulfuryl fluoride (SO2FCl) based on a tertiary amine catalytic system, belonging to the field of chemical engineering and fine fluorine chemical synthesis technology.

[0053] To address the technical bottlenecks in existing processes, such as irreversible catalyst consumption, difficulty in separating byproducts, and high impurity content of sulfuryl fluoride (SO2F2), this paper proposes an integrated innovation that integrates gas-liquid reaction system design, precise control of reaction conditions, closed-loop regeneration circulation system, and dual-tower distillation purification process to achieve efficient and continuous production of sulfuryl fluoride chlorine.

[0054] This application uses a tertiary amine hydrofluoric acid adduct (e.g., triethylamine: Et3N·nHF, n = 2–6) as the fluorinating agent, and utilizes excess sulfuryl chloride (SO2Cl2) to react rapidly in a gas-liquid cross-flow manner to generate sulfuryl fluoride (SO2FCl) at 65–100°C and 0.5–2.0 MPa. The generated sulfuryl fluoride and the remaining sulfuryl chloride enter the gas phase, and the liquid byproduct is a tertiary amine hydrochloride hydrofluoride adduct (e.g., triethylamine: Et3N·HCl·(n-1)HF).

[0055] The gaseous product is distilled twice to obtain the product thioyl fluoride chloride, and the excess raw material is returned to the reaction tower for recycling.

[0056] The liquid-phase byproduct (Et3N·HCl·(n-1)HF) is replenished with HF to restore the n value to 2-6. Then, it is heated to above 150℃ (e.g., 150℃-200℃) or subjected to reduced pressure to remove HCl to regenerate the catalyst tertiary amine hydrofluoric acid adduct (Et3N·nHF, n=2-6). The reaction system is then recycled.

[0057] Thionyl chloride raw materials can be used directly or synthesized in situ from sulfur dioxide and chlorine under the catalysis of tertiary amines, forming a closed-loop cycle system.

[0058] Specifically:

[0059] The sulfuryl fluoride-chloride synthesis chamber operates in a tubular (including shell-and-tube) manner. The tertiary amine hydrogen fluoride adduct (represented as R3N·nHF) is fed from the top and flows downward naturally, while sulfuryl chloride is fed from the bottom in gaseous form and flows upward, reacting rapidly through gas-liquid cross-flow.

[0060] The gaseous product, sulfuryl fluoride chloride, is purified by pressure distillation in two towers. The chlorine, sulfur dioxide, hydrogen chloride, and sulfuryl fluoride separated by the light phase removal tower, and the sulfuryl chloride separated by the heavy phase removal tower are all returned to the sulfuryl chloride synthesis chamber as raw materials for recycling.

[0061] The fluorination reagent regeneration process involves transporting a liquid phase containing a tertiary amine hydrochloride hydrogen fluoride adduct (e.g., triethylamine: Et3N·HCl·(n-1)HF) to a regeneration unit, absorbing a metered amount of hydrogen fluoride to increase the n value to 2-6, preferably 3-4, and then heating at 150°C-200°C to remove hydrogen chloride to obtain regeneration.

[0062] The reactor can be a tubular reactor or a falling film absorption reactor.

[0063] The following examples or comparative small-scale experiments used single-tube or tubular reactors made of Hastelloy alloy. Taking a single-tube reactor as an example, the inner diameter of the tube is 15 mm and the tube length is 1.1 m. The top of the tube has a conical gas-liquid separator structure, with liquid entering from the side and venting from the top. The pressure inside the reactor is stabilized by a back pressure valve. The lower part of the tube also has a conical gas-liquid separator structure, with gas entering from the side and liquid exiting from the bottom. The liquid level inside the reactor is maintained by timed liquid drainage.

[0064] Example 1 (Batch Experiment)

[0065] The raw materials are thioyl chloride (SO2Cl2) and triethylamine hydrofluoric acid adduct (Et3N·3HF, n=3).

[0066] Reaction steps:

[0067] 1 L of Et3N·3HF was injected into a single-tube reactor from the top using a constant flow pump at a flow rate of 10 mL / min (0.0807 mol / min). Thionyl chloride, at a molar ratio of 1.2 times that of Et3N·3HF, was heated to boiling and then introduced into the reactor from the bottom at a flow rate of 7.5 L / min (of which the flow rate of thioacryl chloride was 2.17 L / min (0.0968 mol / min)) using nitrogen as the carrier gas, allowing the reaction to proceed in a gas-liquid cross-flow manner. The molar ratio of the tertiary amine hydrofluoric acid adduct to thioacryl chloride in the reactor was 1:1.2. The system pressure throughout the reactor was maintained at 0.5 MPa, and the temperature of the reaction zone was controlled at 65℃ ± 1℃ via a jacket (temperature controlled by a circulating water bath), with a residence time of 120 seconds. The reaction reached steady state after 20 minutes. Sampling and analysis revealed the following composition of the top gaseous products (excluding the carrier gas): SO2FCl 97.5%, SO2F2 1.2%, SO2 0.6%, Cl2 0.4%, and HCl 0.3% (decomposition of thioacryl chloride under gas chromatography conditions). All percentages are volume ratios. The reaction was stopped after all Et3N·3HF had been pumped out, marking the end of the batch.

[0068] Catalyst (fluorinating agent, tertiary amine, hydrofluoric acid adduct) regeneration:

[0069] After processing and sampling the liquid product, it was analyzed by ion chromatography. Its composition was Et3N·0.97HCl·1.98HF. It was then transferred to a regeneration reactor. Under normal pressure, HF gas was introduced and the temperature was controlled at 40 degrees Celsius to supplement HF and increase the n value from 1.98 to 3.0. At this time, the composition of the liquid product was Et3N·0.97HCl·3HF.

[0070] HCl removal and regeneration: The above liquid product Et3N·0.97HCl·3HF was heated to 150℃±2℃ to remove HCl, yielding Et3N·0.2HCl·2.9HF as the regeneration catalyst;

[0071] The regenerated catalyst (Et3N·0.2HCl·2.9HF) was used as the triethylamine hydrofluoric acid adduct for the above-mentioned cyclic reaction with sulfuryl chloride. Keeping other reaction conditions constant, samples were taken for analysis at steady state. The composition of the top gaseous products (excluding the carrier gas) was: SO2FCl 90.5%, SO2F2 1.0%, SO2 0.6%, Cl2 0.5%, and HCl 7.4%. After recovering sulfuryl chloride from the top gaseous products via a condenser, the remaining gas (containing HCl, SO2, etc.) was passed through a NaOH absorption tower to remove HCl, and the purified gas was discharged. The percentages mentioned above are volume ratios. All gas compositions in this application are volume ratios. The regenerated catalyst was used five times, and the selectivity of the SO2FCl reaction remained essentially stable.

[0072] result:

[0073] No solid byproducts are generated in the system; the single-pass loss rate of the catalyst tertiary amine hydrofluoric acid adduct is 0.08%, and the total loss after 50 cycles is <4%.

[0074] Example 2 (Batch experiment, sulfur dioxide and chlorine gas were used instead of sulfuryl chloride, no carrier gas)

[0075] The raw materials are sulfur dioxide with chlorine gas instead of sulfuryl chloride (SO2Cl2) and triethylamine hydrofluoric acid adduct (Et3N·3HF, n=3).

[0076] Reaction steps:

[0077] 1 L Et3N·3HF was injected into the tubular reactor from the top using a constant flow pump at a flow rate of 20 mL / min (0.1613 mol / min). Chlorine and sulfur dioxide, preheated to 110°C in a preheater and mixed at a volume ratio of 1:1, were introduced into the reactor from the bottom at a flow rate of 17.5 L / min (the total flow rate of sulfur dioxide and chlorine was 7.23 L / min (0.1613 mol / min for sulfur dioxide)), allowing the reaction to proceed in a gas-liquid cross-flow manner. The system pressure within the entire reactor was maintained at 2.0 MPa, and the temperature of the reaction zone was controlled at 100°C ± 1°C via a jacket (temperature controlled by a circulating water bath), with a residence time of 15 seconds. The molar ratio of the tertiary amine hydrofluoric acid adduct, chlorine, and sulfur dioxide in the reactor was 1:1.0:1.0. The reaction reached steady state after 20 minutes. Sampling and analysis revealed the following composition of the top gaseous products (excluding the carrier gas): SO2FCl 97.0%, SO2F2 1.0%, SO2 0.7%, Cl2 0.5%, HCl 0.8% (volume percentages). The reaction was stopped after all Et3N·3HF had been pumped out, marking the end of the batch.

[0078] Catalyst regeneration:

[0079] After processing and sampling the liquid product, it was analyzed by ion chromatography. Its composition was Et3N·0.98HCl·1.99HF. It was then transferred to a regeneration reactor and kept at atmospheric pressure and controlled at 60 degrees Celsius. HF was added to control the n value to 3.0. At this point, the composition of the liquid product was Et3N·0.98HCl·3HF.

[0080] HCl removal and regeneration: The above liquid product Et3N·0.98HCl·3HF was kept at 60℃±2℃ and HCl was removed under vacuum reduced to 2kPa to obtain Et3N·0.2HCl·2.9HF as the regeneration catalyst;

[0081] The regenerated catalyst (Et3N·0.2HCl·2.9HF) was used for the cyclic reaction with thiocyanate chloride: keeping other reaction conditions constant, samples were taken for analysis when the reaction reached steady state. The composition of the top gas products (excluding the carrier gas) was: SO2FCl 90%, SO2F2 1.2%, SO2 0.5%, Cl2 0.4%, HCl 7.9%, where the percentages are volume ratios.

[0082] The regenerated catalyst was used five times, and the reaction selectivity remained basically stable.

[0083] Example 3 (Continuous Experiment)

[0084] The raw materials are thioyl chloride (SO2Cl2) and triethylamine hydrofluoric acid adduct (Et3N·3HF, n=3).

[0085] Reaction steps:

[0086] Et3N·3HF was injected into a single-tube reactor from the top using a constant flow pump at a flow rate of 10 mL / min (0.0807 mol / min). Thionyl chloride was heated to 100°C. Nitrogen gas was used as the carrier gas and introduced into the reactor from the bottom at a flow rate of 5.5 L / min (of which the flow rate of thioacryl chloride was 2.35 L / min (0.1049 mol / min)), allowing the reaction to proceed in a gas-liquid cross-flow manner. The entire reactor system pressure was maintained at 0.5 MPa, and the temperature of the reaction zone was controlled at 65°C ± 1°C via a jacket (temperature controlled by a circulating water bath), with a residence time of 120 seconds. The molar ratio of the tertiary amine hydrofluoric acid adduct to thioacryl chloride in the reactor was 1:1.3. When the reaction reached steady state, samples were taken for analysis. The composition of the gaseous products at the top (excluding the carrier gas) was: SO2FCl 94.5%, SO2F2 0.2%, SO2 2.6%, Cl2 2.5%, HCl 0.4%, and the above percentages are volume ratios.

[0087] Liquid product processing: After sampling, its composition is analyzed and HF is added according to the composition. The temperature is controlled at 40 degrees Celsius to increase the n value to 3.0-4.0. The temperature is raised to 150℃±2℃ to remove HCl and regenerate the catalyst for recycling reaction. The gaseous product of the HCl removal reaction is passed into the water absorption tower to produce hydrochloric acid.

[0088] The gaseous product enters the distillation column, where excess sulfuryl chloride is first removed by a short distillation column (heavy removal), and then it passes through a dehydrogenation column. The top gas (HCl / Cl2 / SO2 / SO2F2) of the dehydrogenation column is sent for incineration, and sulfuryl fluoride chloride is obtained at the bottom of the column with a purity of 98%.

[0089] Example 4 (Continuous Experiment)

[0090] Raw materials: sulfuryl chloride (SO2Cl2), triethylamine hydrofluoric acid adduct (Et3N·4.0HF, n=4)

[0091] Reaction steps:

[0092] Et3N·4.0HF was injected into the tubular reactor from the top via a constant flow pump at a rate of 12 mL / min (0.0861 mol / min). Thionyl chloride, heated to 105 °C and vaporized in a vaporizer, was then introduced into the reactor from the bottom using nitrogen as the carrier gas at a rate of 5.1 L / min (of which the flow rate of thioacryl chloride was 2.31 L / min (0.1033 mol / min)). The system pressure inside the reactor was maintained at 0.8 MPa using a back pressure valve, the reaction zone temperature was 75 °C ± 0.5 °C (temperature controlled by heat transfer oil circulation), the gas-liquid cross-flow contact time was 60 seconds, and the molar ratio of the tertiary amine hydrofluoric acid adduct to thioacryl chloride in the reactor was 1:1.2. Samples were taken for analysis when the reaction reached steady state. The gas phase (excluding the N2 carrier gas) contained: SO2FCl 93.5%, SO2F2 0.3%, SO2 3.5%, Cl2 2.1%, and HCl 0.6%.

[0093] Liquid product processing: After sampling, its composition is analyzed. Based on the composition, the temperature is controlled at 60 degrees Celsius and HF is added to n = 3.5-4.5. HCl is removed at 185 degrees Celsius. The regenerated catalyst after HCl removal is used for recycling reaction.

[0094] The gaseous products are first condensed to recover sulfuryl chloride (returned to the reactor), and the remaining gas enters a dual-tower distillation process: Light-phase removal tower: HCl, SO2, and Cl2 discharged from the top of the tower are returned to the sulfuryl chloride synthesis section for reuse. Heavy-phase removal tower: SO2FCl is obtained at the bottom of the tower with a purity of 98.6%.

[0095] Example 5 (Continuous Experiment)

[0096] Raw materials: sulfuryl chloride (SO2Cl2), Et3N·2.8HF (n=2.8)

[0097] Reaction steps:

[0098] A tubular reactor was used, with Et3N·2.8HF injected from the top at a flow rate of 10 mL / min (0.0827 mol / min) using a constant flow pump. Thionyl chloride, heated to 100°C and completely vaporized in a vaporizer, was introduced from the bottom of the reactor using nitrogen as the carrier gas at a flow rate of 6.0 L / min (of which the thioyl chloride flow rate was 2.78 L / min (0.1241 mol / min)). The system pressure was precisely controlled at 0.5 MPa by a back pressure valve, and the reaction zone temperature was maintained at 65°C ± 1°C through a heat transfer oil circulation system. The gas-liquid two-phase cross-flow contact time was set to 120 seconds. The molar ratio of the tertiary amine hydrofluoric acid adduct to thioyl chloride in the reactor was 1:1.5. When the reaction reaches steady state, samples were taken for analysis. The composition of the gaseous products (excluding the carrier gas N2) was: 93.2% sulfuryl fluoride (SO2FCl), 0.2% sulfuryl fluoride (SO2F2), 3.8% sulfur dioxide (SO2), 2.3% chlorine (Cl2), and 0.5% hydrogen chloride (HCl).

[0099] Liquid phase product processing: After sampling, its composition is analyzed. Based on the composition, the temperature is controlled at 60 degrees Celsius, and HF is added to n = 3.0-4.0. The regenerated catalyst after removing hydrogen chloride (HCl) at 185 degrees Celsius is used for recycling reaction.

[0100] The gaseous products are first recovered by a condenser to recover unreacted sulfuryl chloride (which is returned to the reactor for recycling), and the remaining gas enters a dual-tower distillation system: Light component removal tower: Light components (containing SO2 and Cl2) are collected from the top of the tower and transported to the sulfuryl chloride synthesis section after pressurization; Heavy component removal tower: Sulfuryl fluoride chloride with a purity of 98.3% is obtained from the bottom of the tower.

[0101] Example 6 (Continuous experiment, sulfur dioxide and chlorine gas are used instead of sulfuryl chloride)

[0102] Raw materials: sulfur dioxide (SO2) and chlorine (Cl2) are used instead of sulfuryl chloride (molar ratio SO2:Cl2=1:1), and the fluorinating agent is triethylamine hydrofluoric acid adduct (Et3N·3.6HF, n=3.6).

[0103] Reaction steps:

[0104] A SO2 / Cl2 mixture (molar ratio SO2:Cl2 = 1:1) is preheated to 110°C and then introduced into the tubular reactor from the bottom at a flow rate of 15 mL / min (0.1126 mol / min). Et3N·3.6HF is injected into the reactor from the top via a constant flow pump at a flow rate of 15.5 L / min (of which the total flow rate of sulfur dioxide and chlorine is 7.57 L / min (molar flow rates of both sulfur dioxide and chlorine are 0.1689 mol / min)). The system pressure inside the reactor is 1.2 MPa, the reaction temperature is 90°C ± 1°C (temperature controlled by heat transfer oil), and the residence time is 40 seconds. The molar ratio of the tertiary amine hydrofluoric acid adduct, sulfur dioxide, and chlorine in the reactor is 1:1.5:1.5. When the reaction reached steady state, samples were taken for analysis. The composition of the gas phase products was as follows: sulfuryl fluoride (SO2FCl) 92.1%, sulfuryl fluoride (SO2F2) 0.4%, unreacted sulfur dioxide (SO2) 5.2%, unreacted chlorine (Cl2) 1.8%, and hydrogen chloride (HCl) 0.5%.

[0105] Liquid phase product processing: After sampling, its composition is analyzed. Based on the composition of the triethylamine hydrofluoric acid adduct, the temperature is controlled at 50 degrees Celsius and HF is added to n = 4.0-4.5. The regenerated catalyst after removing HCl in the regeneration reactor at 190 degrees Celsius is used for the recycling reaction.

[0106] The gaseous products directly enter the dual-tower system: Light-phase removal tower: The top gas phase (containing SO2 and Cl2) is returned to the bottom feed system of the reactor. Heavy-phase removal tower: 99.1% pure SO2 (FCl) is collected from the bottom of the tower.

[0107] Example 7 (Continuous Experiment)

[0108] Raw materials: Thionyl chloride (SO2Cl2) and tripropylamine hydrofluoric acid adduct (Pr3N·3.5HF, n=3.5).

[0109] Reaction steps:

[0110] Pr3N·3.5HF was injected into the tubular reactor from the top at a flow rate of 18 mL / min (0.1098 mol / min). Thionyl chloride (vaporized at 115 °C) was fed from the bottom with nitrogen as the carrier gas at a flow rate of 7.5 L / min (of which the flow rate of thioacryl chloride was 3.44 L / min (0.1537 mol / min)). The system pressure was 1.5 MPa, the temperature was 85 °C ± 0.5 °C, and the residence time was 30 seconds. The molar ratio of tripropylamine hydrofluoric acid adduct to thioacryl chloride in the reactor was 1:1.4. Samples were taken for analysis at steady state. The composition of the gaseous products was: SO2FCl 94.6%, SO2F2 0.5%, SO2 2.9%, Cl2 1.2%, and HCl 0.8%.

[0111] After processing and sampling the liquid product, its composition was analyzed. Based on the composition of the triethylamine hydrofluoric acid adduct, the temperature was controlled at 60 degrees Celsius, and HF was added to n = 3.5-4.0. The regenerated catalyst after HCl removal was used in the recycling reaction by a thin-film evaporator (180℃ / 50Pa).

[0112] Gas phase distillation: The gas phase (SO2, Cl2) at the top of the light distillation column is returned to the sulfuryl chloride synthesis section; SO2FCl is collected from the side stream of the heavy distillation column with a purity of 99.0%.

[0113] Example 8 (Continuous Experiment)

[0114] Raw materials: Thionyl chloride (SO2Cl2) and tributylamine hydrofluoric acid adduct (Bu3N·3.8HF).

[0115] Reaction steps:

[0116] A tubular reactor was used. Due to the high viscosity of Bu3N·3.8HF, the feed line was maintained at 80℃ throughout to prevent solidification. A constant flow pump injected the feed into the reactor from the top at a flow rate of 6 mL / min (0.0299 mol / min). After complete vaporization in a 125℃ vaporizer, sulfuryl chloride was injected into the reactor from the bottom using nitrogen as a carrier gas at a flow rate of 3.0 L / min (of which the sulfuryl chloride flow rate was 0.67 L / min (0.0299 mol / min)). The reactor system pressure was controlled at 1.8 MPa by a back pressure valve, and the reaction zone temperature was maintained at 95℃±1℃ by a heat transfer oil circulation system. The gas-liquid cross-flow contact time was 100 seconds. The molar ratio of tributylamine hydrofluoric acid adduct to sulfuryl chloride in the reactor was 1:1.0. When the reaction reaches steady state, samples were taken for analysis. The composition of the gaseous products (excluding the carrier gas N2) was: 93.8% sulfuryl fluoride (SO2FCl), 0.3% sulfuryl fluoride (SO2F2), 3.3% sulfur dioxide (SO2), 1.9% chlorine (Cl2), and 0.7% hydrogen chloride (HCl).

[0117] After processing and sampling the liquid product, its composition is analyzed. Based on the composition, the temperature is controlled at 60 degrees Celsius, and HF is added to n = 4.2-4.7. The product is then transported to a falling film reboiler, where the regenerated catalyst after removing HCl at 195 degrees Celsius and atmospheric pressure is used for recycling.

[0118] The gaseous products are condensed at -10℃ to recover sulfuryl chloride, and the remaining gas enters the dual-tower system. Light component removal tower: Light components (containing SO2 and Cl2) are collected from the top of the tower and returned to the sulfuryl chloride synthesis section; Heavy component removal tower: SO2FCl with a purity of 98.6% is obtained from the bottom of the tower.

[0119] Example 9 (Continuous Experiment)

[0120] Raw material: Thionyl chloride (SO2Cl2) and triethylamine hydrofluoric acid adduct (Et3N·2.5HF).

[0121] Reaction steps:

[0122] Et3N·2.5HF was injected into a single-tube reactor from the top using a constant flow pump at a flow rate of 9 mL / min (0.0774 mol / min). Thionyl chloride, vaporized at 100℃, was fed from the bottom of the reactor using nitrogen as the carrier gas at a flow rate of 6.0 L / min (of which the flow rate of thioacryl chloride was 1.91 L / min (0.0851 mol / min)). The single-tube reactor system was maintained at a pressure of 0.7 MPa, a temperature of 70℃ ± 1℃ (temperature controlled by heat transfer oil), and a residence time of 90 seconds. The molar ratio of triethylamine hydrofluoric acid adduct to thioacryl chloride in the reactor was 1:1.1. Samples were taken for analysis at steady state. The composition of the gaseous products was: SO2FCl 91.8%, SO2F2 0.1%, SO2 4.6%, Cl2 3.0%, and HCl 0.5%.

[0123] Liquid product processing: After sampling, its composition is analyzed. Based on the composition of the triethylamine hydrofluoric acid adduct, the temperature is controlled at 40 degrees Celsius and HF is added to n = 3.0-3.5. The regenerated catalyst after HCl removal in the regeneration reactor (180°C) is used for the recycling reaction.

[0124] Gas-phase distillation: The top gas from the light distillation column contains 31% SO2 and 20% Cl2, which is compressed and used for the synthesis of thioacryl chloride; SO2FCl is obtained from the bottom of the heavy distillation column with a purity of 98.8%.

[0125] Comparative Example 1 (No Regeneration Addition)

[0126] Repeat the conditions of Example 1, but without supplementing the HF-regenerated catalyst:

[0127] 1. The solid precipitate (Et3N·HCl) in the liquid phase accounts for 40 wt%;

[0128] 2. The system pressure increased by 0.4 MPa every 24 hours, forcing a shutdown for cleaning.

[0129] Comparative Example 2: Contact time too short

[0130] Parameter settings:

[0131] Reactor type: Same as the tubular reactor in Example 2.

[0132] Gas-liquid contact time: By changing the raw material flow rate, the gas-liquid contact time, i.e. the residence time, is made to be 5 seconds (below the lower limit of 15 seconds).

[0133] Other conditions: Same as in Example 2 (temperature 100℃, pressure 2.0MPa, n=3, SO2:Cl2=1:1)

[0134] result:

[0135] Composition of gas phase products: SO2FCl 78.3%, SO2F2 0.8%, SO2 12.5%, Cl2 5.2%, HCl 3.2%. The yield of thioacyl fluoride chloride decreased to 76.5%. Unreacted tertiary amine hydrofluoric acid adduct remained in the liquid phase (analyzed by ion chromatography as Et3N·HCl·2.6HF).

[0136] Cause analysis:

[0137] Insufficient contact time leads to inadequate gas-liquid mass transfer, and the tertiary amine hydrofluoric acid adduct fails to fully release HF, resulting in incomplete sulfuryl chloride synthesis reaction (high SO2 / Cl2 residue), and the HF in the ammonium salt (triethylamine hydrofluoric acid salt) is not effectively consumed.

[0138] Comparative Example 3: Excessive Contact Time

[0139] Parameter settings:

[0140] Reactor type: Same as the single-tube reactor in Example 1.

[0141] Gas-liquid contact time: By changing the raw material flow rate, the gas-liquid contact time, i.e. the residence time, is made to be 180 seconds (higher than the upper limit of 120 seconds).

[0142] Other conditions: Same as in Example 1.

[0143] result:

[0144] Composition of gaseous products: SO2FCl 89.7%, SO2F2 6.1%, SO2 1.0%, Cl2 0.5%, HCl 2.7%.

[0145] The viscosity of the liquid phase byproducts increased significantly (including polymeric sulfides), and the yield dropped to 82% when the catalyst was recycled for the third time after regeneration.

[0146] Cause analysis:

[0147] Excessive gas-liquid contact time (residence time) exacerbates the secondary fluorination of sulfuryl fluoride (SO2FCl→SO2F2) and the hydrolysis of sulfuryl fluoride (SO2Cl2+H2O→SO2+2HCl). Prolonged high-temperature residence in the liquid phase leads to the decomposition of amine salts, forming a gel-like substance that can clog equipment.

[0148] Comparative Example 4: Temperature Too High

[0149] Parameter settings:

[0150] Reaction temperature: 110℃ (above the upper limit of 100℃).

[0151] Other conditions: Same as in Example 4 (pressure 0.8 MPa, n = 4).

[0152] result:

[0153] Composition of gaseous products: SO2FCl 41.2%, SO2F2 51.1%, SO2 5.1%, Cl2 1.8%, HCl 0.8%. Black tar-like solid residue (triethylamine degradation product) after catalyst regeneration cycle.

[0154] Cause analysis:

[0155] High temperature accelerates the Hoffmann elimination reaction of tertiary amines (Et3N→C2H4+Et2NH), leading to catalyst deactivation; at the same time, it promotes the isomerization of SO2FCl to SO2F2 (byproduct SO2F2 increases dramatically).

[0156] Comparative Example 5 - Temperature Too Low

[0157] Parameter settings:

[0158] Reactor: Same as the single-tube reactor in Example 1.

[0159] Reaction temperature: 40℃ (<65℃ lower limit).

[0160] Pressure / Time / Raw Material / Molar Ratio: Same as Example 1.

[0161] Carrier gas: N2, total flow rate 7.5 L / min.

[0162] result:

[0163] Gas phase composition (volume ratio):

[0164] SO2FCl 52.7%; SO228.6%; Cl2 12.5%; HCl 5.9%; SO2F20.3%.

[0165] Liquid phase residue:

[0166] Analysis of the liquid phase byproducts showed that the composition was Et3N·0.2HCl·2.8HF, indicating a high HF residue.

[0167] White crystals of SO2Cl2·Et3N precipitated at the reactor outlet.

[0168] Thionyl fluoride chloride yield: 49.1% (thioyl fluoride chloride)

[0169] reason:

[0170] Low temperature causes:

[0171] 1. Insufficient HF dissociation leads to low SO2 / Cl2 consumption.

[0172] 2. Increased liquid phase viscosity leads to deterioration of mass transfer.

[0173] 3. Thionyl chloride forms an adduct with an amine and crystallizes.

[0174] Comparative Example 6: Excessive Pressure

[0175] Parameter settings:

[0176] Pressure: 2.5 MPa (above the upper limit of 2.0 MPa).

[0177] Other conditions: Same as in Example 6 (temperature 90℃, n=3.6).

[0178] result:

[0179] Composition of gaseous products: SO2FCl 35.6%, SO2F2 0.9%, SO2 32.8%, Cl2 25.7%, HCl 5.0%. Liquid chlorine accumulated at the bottom of the reactor, and the distillation system was blocked.

[0180] Cause analysis:

[0181] Overpressure liquefies chlorine (critical pressure 3.8 MPa), disrupting gas-liquid cross-flow dynamics; excess chlorine inhibits the main reaction (Cl2 + SO2 → SO2Cl2 equilibrium shifts to the left), leading to a surge in raw material residue.

[0182] Comparative Example 6: Pressure Too Low

[0183] Parameter settings:

[0184] Reactor: Same as the tubular reactor in Example 6.

[0185] Pressure: 0.3 MPa (<0.5 MPa lower limit).

[0186] Temperature / raw material / molar ratio / flow rate: Same as Example 6 (temperature 90℃, pressure 1.2MPa, n=3.6).

[0187] result:

[0188] Gas phase composition (volume ratio):

[0189] SO2FCl 38.5%; SO235.2%; Cl221.1%; HCl 4.7%; SO2F20.5%.

[0190] Liquid phase characteristics:

[0191] Analysis of the liquid phase byproducts showed that the composition was Et3N·0.1HCl·3.2HF, with HF consumption of <5%, indicating high HF residue.

[0192] HF vapor leakage was detected at the top of the reactor (fluoride ion test paper turned red).

[0193] Yield: 44.3% (thioyl fluoride chloride)

[0194] reason:

[0195] Low pressure leads to:

[0196] 1. Gas volume expansion results in a residence time of less than 5 seconds.

[0197] 2. The gas-liquid mass transfer area decreases, resulting in insufficient SO2 / Cl2 reaction.

[0198] 3. Increased HF vapor pressure leads to catalyst loss.

[0199] Comparative Example 7: The n-value of the admixture is too low

[0200] Parameter settings:

[0201] n value: 1.8 (below the lower limit of 2), that is, the tertiary amine hydrofluoric acid adduct is Et3N·1.8HF (n=1.8).

[0202] Other conditions: Same as in Example 5 (temperature 65°C, pressure 0.5 MPa)

[0203] result:

[0204] Composition of gaseous products: SO2FCl 32.5%, SO2F 20.1%, SO2 28.3%, Cl2 18.9%, HCl 20.2%. Solid Et3N·HCl precipitated in the liquid phase (blocking the pipeline), and the n value could not be restored to 3.0 after regeneration.

[0205] Cause analysis:

[0206] Insufficient HF causes tertiary amines to preferentially form hydrochloride (Et3N+HCl→Et3N·HCl) rather than active fluorinated adducts; adducts with low n values ​​have low viscosity but weak catalytic activity, resulting in a significant decrease in reaction rate.

[0207] Comparative Example 7: The n-value of the admixture is too high

[0208] Parameter settings:

[0209] n value: 6.2, that is, the tertiary amine hydrofluoric acid adduct is Et3N·6.2HF.

[0210] Other conditions: Same as in Example 4 (temperature 75°C, pressure 0.8 MPa, n = 4).

[0211] result:

[0212] Gas phase composition (volume ratio):

[0213] SO2FCl 39.8%; SO2F212.3%; SO218.5%; Cl29.7%; HCl 19.7%

[0214] Characteristics of liquid phase byproducts: excessively high viscosity.

[0215] Thionyl fluoride yield: 51.6%.

[0216] Reason: High n value leads to

[0217] 1. In the tertiary amine hydrofluoric acid adduct, HF is supersaturated, leading to a direct reaction between free HF and SO2Cl2:

[0218] HF + SO2Cl2 → SO2F2 + 2HCl.

[0219] 2. The excessively high viscosity of liquid phase byproducts leads to a sharp increase in the resistance to mass transfer in the liquid film.

[0220] Comparative Example 8: Imbalance in Raw Material Ratio

[0221] Parameter settings:

[0222] SO2:Cl2 = 1:1.8 (Cl2 in excess, exceeding the range of 1.0 to 1.5)

[0223] Other conditions: Same as in Example 6 (temperature 90℃, pressure 1.2MPa, n=3.6)

[0224] result:

[0225] Composition of gaseous products: SO2FCl 40.7%, SO2F2 1.1%, Cl2 38.5%, SO2 4.2%, HCl 15.5%. The Cl2 concentration in the overhead gas of the light removal tower is too high to be directly returned to the synthesis of thioacryl chloride.

[0226] Cause analysis:

[0227] Excess chlorine gas initiates a free radical side reaction (Cl· + SO2FCl → SO2F· + Cl2), reducing selectivity; high Cl2 partial pressure inhibits SO2 conversion (SO2 + Cl2 → SO2Cl2 equilibrium shifts to the left).

[0228] Comparative Example 9: Imbalance in Raw Material Ratio

[0229] Parameter settings:

[0230] R3N·nHF:thioyl chloride = 1:1.8 (>1.5 upper limit).

[0231] Other conditions: Same as in Example 5.

[0232] result:

[0233] Gas phase composition (volume ratio):

[0234] SO2FCl 83.5%; SO29.7%; Cl23.1%; HCl 3.2%; SO2F20.5%

[0235] Liquid phase characteristics:

[0236] Analysis of the liquid phase byproducts showed that the composition was Et3N·1.5HCl·0.3HF, indicating that HF ​​was depleted.

[0237] The HF replenishment amount increases by 200% during regeneration.

[0238] Yield:

[0239] The yield of thioyl fluoride chloride was 87.1%.

[0240] The amine catalyst loss rate was 18%, indicating irreversible deactivation of the amine catalyst.

[0241] Cause: Excessive sulfuryl chloride

[0242] 1. Predatory consumption of HF: SO2Cl2 + 4HF → SO2F2 + 4HCl, that is, excessive fluorination leads to the formation of sulfuryl fluoride, rather than sulfuryl fluoride chloride.

[0243] 2. Protonation of amine nuclei: Et3N + HCl → [Et3NH]Cl, which leads to permanent loss of catalytic activity.

[0244] 3. The thermal decomposition of thiocyanate is accelerated.

Claims

1. A method for preparing thioyl fluoride chloride, characterized in that, The preparation method includes: reacting a tertiary amine hydrofluoric acid adduct with a thioyl chloride at 65–100 degrees Celsius and 0.5–2.0 MPa for 15–120 seconds to obtain a thioyl fluoride chloride; wherein the molar ratio of the tertiary amine hydrofluoric acid adduct to the thioyl chloride is 1:(1.0–1.5). Alternatively, the preparation method includes: reacting a tertiary amine hydrofluoric acid adduct, sulfur dioxide, and chlorine at 65–100 degrees Celsius and 0.5–2.0 MPa for 15–120 seconds to obtain thioacryl fluoride; wherein the molar ratio of the tertiary amine hydrofluoric acid adduct, sulfur dioxide, and chlorine is 1:(1.0–1.5):(1.0–1.5).

2. The preparation method according to claim 1, characterized in that, The tertiary amine hydrogen fluoride adduct is represented as R3N·nHF, where n is 2 to 6.

3. The preparation method according to claim 1, characterized in that, The preparation method further includes: reacting the liquid-phase byproduct tertiary amine hydrochloride hydrogen fluoride adduct with hydrogen fluoride, and then removing hydrogen chloride under reduced pressure or heating to obtain the tertiary amine hydrofluoric acid adduct for recycling.

4. The preparation method according to claim 3, characterized in that, The liquid-phase byproduct, the tertiary amine hydrochloride hydrogen fluoride adduct R3N·HCl·(n-1)HF, is reacted with hydrogen fluoride to obtain the tertiary amine hydrochloride hydrogen fluoride adduct R3N·HCl·nHF, where n is 2 to 6.

5. The preparation method according to claim 1, characterized in that, The thioyl fluoride chloride is present in the gaseous product, and the thioyl fluoride chloride product is obtained by pressurized distillation purification of the gaseous product.

6. The preparation method according to claim 1, characterized in that, The thioyl chloride is synthesized from sulfur dioxide and chlorine under the catalysis of a tertiary amine.

7. The preparation method according to claim 1, characterized in that, The tertiary amine in the tertiary amine hydrofluoric acid adduct is selected from C3-C12 aliphatic tertiary amines.

8. The preparation method according to claim 1, characterized in that, The reaction proceeds via a gas-liquid crossflow.

9. The preparation method according to claim 3, characterized in that, The conditions for reacting the liquid-phase byproduct, tertiary amine hydrochloride hydrogen fluoride adduct, with hydrogen fluoride are: ambient pressure, 40-60 degrees Celsius.