Method and system for continuously preparing and filling electronic grade thionyl fluoride

Abstract

The invention belongs to the technical field of chemical engineering, and particularly relates to a method and a system for continuously preparing and filling electronic-grade thionyl fluoride. The method comprises the steps of raw material mixing and preheating, reaction synthesis and crude product separation, light component removal treatment, rectification and purification, vaporization and pressurization, impurity adsorption, metering and filling and the like. Impurities such as hydrogen chloride, hydrogen fluoride and the like are removed in a mode of combining reactive distillation, two-stage distillation separation and three-stage adsorption, and finally high-purity thionyl fluoride gas is obtained and automatically filled into a steel cylinder. The system comprises a mixer, a preheater, a reaction tower, a condenser, a rectifying tower, a vaporizer, an adsorption tower, a filling device and other modules, realizes full-flow continuous operation from raw materials to products, and is suitable for high-purity preparation requirements of the electronic gas industry.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical industry, and in particular relates to a method and system for the continuous preparation and filling of electronic-grade thionyl fluoride. Background Art

[0002] Thionyl fluoride (SOF2) is a colorless gas commonly used in pesticides, sterilants, and as an etchant and cleaning agent in the semiconductor industry. Electronic-grade applications, in particular, place extremely high demands on its purity, stability, and packaging. With the rapid development of the semiconductor, chip manufacturing, and optoelectronics industries, market demand for electronic-grade thionyl fluoride is rapidly increasing, and its preparation and purification processes are facing greater technical challenges.

[0003] Traditional methods for preparing thionyl fluoride often employ a batch reaction model, typically reacting thionyl chloride with a fluorination agent (such as potassium fluoride or hydrogen fluoride) to produce the target product. However, these methods suffer from long reaction cycles, numerous byproducts, high operational risks, and difficulty in achieving automated control. In particular, post-reaction gas production is discontinuous, and the purification process relies on manual intervention, resulting in unstable product purity and difficulty meeting the strict control requirements for impurities (such as moisture, acidic gases, and particulate matter) required for electronic-grade applications.

[0004] Furthermore, the existing thionyl fluoride filling process is generally manual or semi-automatic, with the gas being directly charged into cylinders after simple condensation or absorption treatment. This method not only poses safety risks such as gas leakage and overpressure filling, but also makes it difficult to ensure the uniformity and stability of different batches of products, making it impossible to achieve efficient and continuous operation of the production line. Therefore, there is an urgent need to develop a continuous preparation and filling system and method for electronic-grade thionyl fluoride with high reaction efficiency, controllable product purity, and online purification and automatic filling capabilities to meet the actual needs of the modern electronics manufacturing industry. Summary of the Invention

[0005] In view of the above problems, the object of the present invention is to propose: a method for the continuous preparation and filling of electronic-grade thionyl fluoride, which adopts anhydrous hydrogen fluoride (AHF) and thionyl chloride (SOCl2) to synthesize thionyl fluoride (SOF2) product in a one-step method, then separates the product by distillation, and finally removes trace impurities by three-stage adsorption to obtain a high-purity electronic-grade thionyl fluoride product.

[0006] The reaction equation is as follows:

[0007] SOCl2+2HF→SOF2+2HCl

[0008] Anhydrous hydrogen fluoride (AHF) and thionyl chloride (SOCl2) are metered and fully mixed in mixer M1. Then, they are preheated in preheater E1 and enter reactive distillation tower T1. The bottom liquid is circulated back to the tower through distillation circulation pump P1. The mixed material is fully reacted under the conditions of 50-150°C and 0-0.5 MPa. The thionyl fluoride (SOF2) and hydrogen chloride (HCl) generated by the reaction are filled into the tower top in the form of gas and enter condenser E2 for condensation and separation. The thionyl fluoride condenses into liquid. Part of it flows back to the tower top, and part is extracted to the crude product tank V1. The hydrogen chloride gas is discharged from the device;

[0009] The crude thionyl fluoride is preheated in the preheater E4 and then enters the light components removal tower T2. A trace amount of light components are removed from the top of the tower. The bottom liquid enters the distillation tower T3 for purification. The thionyl fluoride product that meets the purity requirements is obtained from the top of the tower. After condensing into liquid, it enters the storage tank V2 for storage. The bottom liquid is circulated back to the mixer for cyclic reaction.

[0010] The method comprises the following steps:

[0011] S1. Raw material mixing and preheating: anhydrous hydrogen fluoride and thionyl chloride are measured in a molar ratio of 2:1, mixed in a mixer, and the mixture is heated to 50-100° C. in a first preheater;

[0012] S2, reaction and crude product separation: the mixture is fed into a reactive distillation tower, the temperature in the tower is maintained at 80-150°C, the reaction pressure is controlled at 0-0.5 MPa, the bottom liquid is refluxed by a circulating pump, the gas mixture generated during the reaction is discharged from the top of the tower, introduced into a condenser, and gas-liquid separation is performed under a cooling condition below -70°C to obtain liquid thionyl fluoride and gaseous hydrogen chloride, wherein part of the liquid thionyl fluoride is refluxed to the top of the tower, and the rest enters the crude product tank, and the gaseous hydrogen chloride is discharged through the outlet;

[0013] S3, light component removal treatment: The thionyl fluoride in the crude product tank is heated to 30-50°C and transported to the light component removal tower, where the light components are removed at a temperature of 0-30°C and normal pressure. The light components escape from the top of the tower and the product flows out from the bottom of the tower;

[0014] S4, distillation purification: the thionyl fluoride product after light removal is introduced into a distillation tower, separated and purified at 30-50°C, and the thionyl fluoride product with electronic grade purity requirements is extracted from the top of the tower. The reflux ratio is controlled at 5-10, part of it is refluxed to the top of the tower, and the rest flows into the product tank. The bottom liquid contains hydrogen fluoride components and is returned to the mixer to mix with new raw materials;

[0015] S5. Vaporization and compression: The liquid thionyl fluoride in the product tank is fed into the vaporizer, the temperature of which is controlled at 50-100°C to generate gaseous thionyl fluoride. The gas is pressurized to 1-1.5 MPa by a compressor and introduced into a high-pressure buffer tank.

[0016] S6. Impurity adsorption: The gas in the high-pressure buffer tank passes through three sets of adsorption towers in sequence, and the molecular sieve material is used to adsorb hydrogen fluoride and hydrogen chloride respectively. The towers are connected in series. The high-pressure product gas enters the high-pressure product tank after being treated in the three-stage adsorption tower;

[0017] S7. Metering and filling: The gas in the high-pressure product tank is filled into the cylinder through a metering device. The filling process includes flow control and pressure regulation to complete the collection of electronic-grade thionyl fluoride products.

[0018] In a preferred technical solution, the mass of anhydrous hydrogen fluoride pre-charged into the reactor of the reactive distillation tower is controlled at 5 to 10 kg. The filling step is completed before the introduction of the raw material mixture. The reactor bottom liquid is circulated in a closed loop between the distillation circulation pump and the reboiler to form a reflux loop to maintain the reactor bottom liquid level and reaction temperature.

[0019] In a preferred technical solution, the condenser used in step S2 adopts a physical temperature-controlled refrigerant, and the operating temperature of the refrigerant is lower than -70°C. The top of the condenser is provided with a gas outlet for discharging hydrogen chloride, and the bottom liquid phase outlet is connected to the crude product tank.

[0020] In a preferred technical solution, the operating pressure of the light component removal tower in step S3 is atmospheric pressure, a reboiler is provided in the kettle of the light component removal tower to maintain the bottom temperature at no more than 30°C, a condenser is provided at the top of the tower to condense the light component vapor, and the reflux ratio is no more than 1.

[0021] In a preferred technical solution, the reflux ratio of the distillation tower is set to 5-10, a condenser is provided at the top of the tower and connected to the reflux device, a reboiler is provided at the bottom of the tower for heating, and the liquid at the bottom of the distillation tower is discharged to the inlet of the mixer for use in subsequent circulation reactions.

[0022] In a preferred technical solution, the vaporizer is a shell and tube heat exchange device, the inlet of which is connected to the liquid product tank, the outlet of which is connected to the compressor, the heating medium is introduced into the shell side, and the temperature adjustment range is 50-100°C; the compressor outlet is connected to a high-pressure buffer tank, and the buffer tank is provided with a safety valve and a sampling port.

[0023] In a preferred technical solution, the adsorption materials in the three-stage adsorption tower are hydrogen fluoride selective adsorbent, hydrogen chloride selective adsorbent and residual gas adsorbent in sequence. The three groups of adsorption towers are independent cylindrical structures, and are equipped with online temperature monitoring and pressure difference sensors. After adsorption saturation, they are activated at a temperature of 200-300°C to restore their performance.

[0024] The present invention also provides an electronic-grade thionyl fluoride continuous preparation and filling system for implementing the method, comprising:

[0025] A raw material metering unit, used for proportional metering of anhydrous hydrogen fluoride and thionyl chloride;

[0026] a raw material mixer, connected to the metering unit, for forming a uniform mixture;

[0027] a first preheater connected to the mixer outlet;

[0028] Reactive distillation tower, the top of the tower body is connected to the condenser, and the bottom of the tower is connected to the distillation circulation pump and the reboiler;

[0029] a crude product tank connected to the liquid phase outlet of the condenser;

[0030] The light removal tower has a feed port connected to the crude product tank and is equipped with a light removal condenser and a reboiler;

[0031] The distillation tower has its feed port connected to the kettle of the light removal tower, its top connected to the condenser and reflux system, and its kettle connected to the reflux recycling pipeline;

[0032] Product tank, connected to the extraction pipeline at the top of the distillation tower;

[0033] The vaporizer, compressor and high-pressure buffer tank constitute the pressurization module;

[0034] The adsorption tower module includes three groups of adsorption towers connected in series;

[0035] High-pressure product tank, connected to the outlet of the adsorption tower module;

[0036] Automatic metering and filling system for gas filling.

[0037] In a preferred technical solution, each adsorption tower of the adsorption tower module includes a cylinder, a packing layer, a temperature probe, an air inlet and outlet, and a bypass valve. The adsorption tower is provided with an external insulation layer, and the adsorbent filling density is 0.4-0.6 g / cm 3 .

[0038] In a preferred technical solution, the automatic metering and filling system includes a flow meter, a pressure regulating valve, an anti-backflow check valve, a vacuum exhaust port and a filling interface with a standard threaded connection. The flow meter accuracy is better than ±1%, and the working range of the pressure regulating valve is 0.2~2MPa.

[0039] Beneficial effects

[0040] The present invention provides a method and system for the continuous preparation and filling of electronic-grade thionyl fluoride, which has the following beneficial effects:

[0041] First, the present invention uses a reactive distillation tower to achieve the coupled operation of raw material mixing reaction and rough separation. Anhydrous hydrogen fluoride and thionyl chloride react under controlled conditions in the tower to produce thionyl fluoride, and the by-product hydrogen chloride is simultaneously separated. This not only reduces the number of equipment but also effectively utilizes the heat in the tower, improves the reaction conversion rate and energy utilization efficiency, and provides a stable foundation for continuous preparation.

[0042] Secondly, in the subsequent separation process, a light-removal tower is set up to remove low-boiling-point impurities, and then the main product thionyl fluoride is purified through a distillation tower to make its purity meet electronic grade requirements. The process flow is rigorous and reasonable, which can effectively reduce the content of residual hydrogen fluoride and other light components in the product, ensuring the safety and reliability of the product in microelectronics technology.

[0043] Finally, after vaporization and compression, the product passes through a three-stage series adsorption tower to remove residual impurities, further improving gas purity. High-temperature activation is also used to regenerate the adsorbent, reducing operating costs. Furthermore, a supporting automatic metering and filling system delivers quantitative gas output, ensuring precise flow and pressure control during the filling process. This facilitates standardized packaging and batch delivery of the product, making it suitable for large-scale industrial deployment. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 Schematic diagram of the system structure of the present invention.

[0045] Among them: M1-mixer; E1-preheater; T1-reaction distillation tower; E2-condenser; E3-reaction reboiler; V1-crude product tank; P1-distillation circulation pump; P2-light removal feed pump; E4-light removal preheater; T2-light removal tower; E5-light removal condenser; E6-light removal reboiler; P3-distillation feed pump; T3-distillation tower; E7-distillation condenser; E8-distillation reboiler; P4-distillation discharge pump; V2-liquid product tank; E9-vaporizer; V3-vaporization buffer tank; C1-compressor; V4-high-pressure buffer tank; T4~T6-adsorption towers; V5-high-pressure product tank. DETAILED DESCRIPTION

[0046] In order to deepen the understanding of the present invention, the present invention will be further described in detail below with reference to the examples. The examples are only used to explain the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0047] Example 1

[0048] This embodiment provides a method for the continuous preparation and filling of electronic-grade thionyl fluoride. This method is based on a process flow of raw material reaction, product separation, gas purification, and automatic filling. Through precise control of temperature, pressure, reflux ratio, and adsorption device, it achieves continuous preparation and standardized output of high-purity thionyl fluoride gas. Specifically, it includes the following steps:

[0049] S1. Raw material mixing and preheating

[0050] In this step, a high-precision metering pump is used to transport anhydrous hydrogen fluoride and thionyl chloride from their respective raw material storage tanks to the mixer inlet, and a flow meter is used to ensure that the molar ratio of the two is 2:1. The mixer is a double-screw or static tube mixing device, and the shell adopts a polytetrafluoroethylene lined structure to adapt to corrosive gas media. The mixed materials are sent to the first preheater via a corrosion-resistant conveying pipeline. The preheater adopts a shell and tube structure, and the heat transfer medium is hot oil or saturated water vapor. The outlet temperature is controlled between 50 and 100 ° C. Temperature regulation is completed by an external thermostatic valve and a feedback thermocouple. This step is intended to provide suitable physical state and energy conditions for the subsequent reaction process, ensuring that the material has good fluidity and reactivity when entering the reaction distillation tower.

[0051] S2. Reaction and crude product separation

[0052] The mixed and preheated materials enter the reactive distillation column from the middle section. This column is a packed distillation reaction column, using a corrugated fluoroplastic packing material to enhance the gas-liquid contact area. The column is equipped with multiple temperature sampling ports, and the reactor is equipped with an external reboiler to maintain the reaction heat supply. The reactor is pre-filled with 5-10 kg of anhydrous hydrogen fluoride liquid to form the initial reaction liquid. A circulating pump forms a stable circuit, allowing the refluxed material to continuously exchange heat with the descending material. At 80-150°C and 0-0.5 MPa, thionyl chloride reacts with anhydrous hydrogen fluoride to produce thionyl fluoride and hydrogen chloride gas as a byproduct. The reaction gases escape from the top of the column and enter the condenser through the top outlet. The condenser utilizes a dual-effect cooling system using metal fins and a low-temperature refrigerant, with the refrigerant temperature controlled below -70°C. A three-way valve is installed at the condenser outlet to separate the thionyl fluoride liquid from the uncondensed gas. Part of the condensed thionyl fluoride is refluxed to the top of the column to maintain the liquid concentration within the column, while the remainder is directed to a crude product tank for storage. Gaseous hydrogen chloride is discharged through the top outlet and can be collected as a by-product or neutralized and discharged for treatment.

[0053] S3, light removal treatment

[0054] The thionyl fluoride in the crude product tank is pumped to the feed port of the light component removal tower. A preheater is installed in front of the tower to raise the feed temperature to 30-50°C to improve the escape ability of light components. The light component removal tower is a normal pressure operation tower. Its kettle is equipped with a jacketed steam heating system to control the bottom temperature between 0 and 30°C. The tower structure uses structured packing to improve the separation efficiency in the tower. A condenser is installed at the top of the tower to recover part of the light component vapor. The reflux ratio of the light component is adjusted to ≤1 through the condenser to ensure that the light impurities are effectively removed and reduce interference with subsequent purification processes. The product after light component removal is output from the bottom of the tower and enters the next step.

[0055] S4, distillation and purification

[0056] The light-removal product is output from the bottom of the light-removal tower and introduced into the distillation tower for purification by gravity or pumping. The distillation tower is equipped with multi-stage trays and high-efficiency packings. The top temperature is maintained at 30-50°C, and the bottom temperature is maintained at no more than 55°C by heating with a steam reboiler. The top of the tower is connected to a condenser to form a reflux system, and the reflux ratio is set to 5-10. The product thionyl fluoride is separated in liquid form after condensation at the top of the tower, part of which is refluxed to the reflux port at the top of the tower, and the rest is sent to the product storage tank for storage. The bottom liquid is mainly hydrogen fluoride residual liquid, which is collected and returned to the raw material mixing link for reuse, reducing raw material loss and forming a closed-loop process.

[0057] S5. Vaporization and compression

[0058] Liquid thionyl fluoride in the storage tank is fed through an insulated pipeline into the vaporizer, a shell-and-tube heat exchanger. A heating medium is introduced into the shell side of the vaporizer, maintaining a temperature of 50-100°C. The vaporized thionyl fluoride then enters the compressor, a two-stage, water-cooled centrifugal unit with a stable outlet pressure of 1-1.5 MPa. The compressed gas flows into a high-pressure buffer tank, equipped with a pressure reducing valve, rupture disk, and pressure gauge to ensure pressure stability in subsequent processes. The inner wall of the buffer tank is coated with a fluoropolymer lining to prevent gas corrosion, and a top sampling port is provided to facilitate online monitoring of gas impurities.

[0059] S6, impurity adsorption

[0060] The thionyl fluoride gas in the high-pressure buffer tank is introduced into three groups of adsorption towers in sequence through pipelines. The first adsorption tower is filled with a selective adsorbent for hydrogen fluoride, the second adsorption tower is filled with a selective adsorbent for hydrogen chloride, and the third adsorption tower is filled with activated carbon-based high specific surface area materials to remove residual micro-impurities. Each adsorption tower is an independent stainless steel cylindrical structure with a built-in temperature monitoring module and a pressure difference alarm system to monitor the adsorption saturation level. After each group of adsorbents has been used for a period of time, it can be switched to a bypass tower body. The original tower undergoes high-temperature regeneration operation, using hot air or an electric heating system to heat to 200-300°C. After desorbing impurities, it is replaced with nitrogen for cooling and can be put back online for use. The high-purity thionyl fluoride gas after adsorption enters the high-pressure product tank, which is equipped with an inner lining coating, a sampling port, and a safety vent interface.

[0061] S7, metering filling

[0062] The outlet of the high-pressure product tank is connected to an automated metering and filling system consisting of a mass flow meter, an intelligent pressure regulating valve, a flow limiter, and overpressure protection components. A standard cylinder interface with a vacuum displacement mechanism and a sealed closure is installed at the end of the filling line. The filling process is program-controlled, with independent flow metering for each bottle, ensuring stable output gas pressure and a single-bottle filling tolerance of ±1%. After filling, the system records the filling time, bottle number, flow rate, and pressure data, enabling full traceability of product flow.

[0063] In this embodiment, key components of the equipment, including the mixer, reaction tower, distillation tower, adsorption tower, and compression pump, are constructed from corrosion-resistant metal and fluoroplastic composites, with fluororubber seals used at device joints. The control system utilizes a PLC centralized monitoring structure, enabling multi-parameter linkage adjustment and alarm prompts via an industrial touchscreen, ensuring stable and safe operation. The entire system supports 24 / 7 continuous operation, boasts excellent scalability and process stability, and is suitable for the stable, large-scale production of electronic-grade gases in the electronics and chemical industries.

[0064] Example 2

[0065] This embodiment provides a system for the continuous preparation and filling of electronic-grade thionyl fluoride. The system integrates raw material mixing, reaction synthesis, crude product separation, product distillation, impurity adsorption, and filling modules, and is suitable for achieving continuous, high-purity industrial production of SOF2 gas. The system components have clear connections, stable operation processes, and automatic control and online monitoring capabilities. Specifically, it includes the following units and equipment configurations:

[0066] 1. Raw material mixing and preheating unit:

[0067] The unit mainly includes M1-mixer and E1-preheater, which are used to complete the fixed ratio mixing and temperature regulation of anhydrous hydrogen fluoride and thionyl chloride.

[0068] The M1 is a tubular mixer, constructed from corrosion-resistant alloy steel or PTFE-lined stainless steel. It features static mixing blades or a high-shear vortex section to enhance the uniformity of the two liquid feedstocks. A flow meter and proportional valve are installed at the mixer's feed end to ensure a constant 2:1 molar ratio.

[0069] E1 is a shell-and-tube heat exchanger that utilizes thermal oil circulation for heating. The preheater is equipped with inlet and outlet temperature probes to control the outlet temperature between 50 and 100°C to enhance the reactivity of the mixture.

[0070] 2. Reaction and crude product separation unit:

[0071] The module includes T1-reaction distillation tower, E2-condenser, E3-reaction reboiler, V1-crude product tank, and P1-distillation circulation pump.

[0072] T1 is a packed distillation tower with a diameter of 300-800 mm. Structured packing made of perfluorinated materials or high molecular weight polymers is installed to enhance gas-liquid contact within the tower. 5-10 kg of anhydrous hydrogen fluoride is pre-added to the bottom of the tower as a reaction starter. A liquid level gauge and temperature-controlled reboiler E3 are installed on the bottom side of the tower. E3 is a steam heating device that, in conjunction with the P1 circulating pump, recirculates and heats the bottom liquid, ensuring continuous reaction at 80-150°C and 0-0.5 MPa.

[0073] The reaction gas is discharged from the top of tower T1 and cooled to below -70°C in the E2 condenser using ethanol / dry ice or mechanical refrigeration. The E2 condenser has an upper vapor outlet and a lower liquid outlet. Hydrogen chloride escapes through the upper outlet, while a portion of the thionyl fluoride liquid refluxes to the top of tower T1, and the remainder flows from the bottom into crude product tank V1 for temporary storage.

[0074] 3. Lightweight processing module:

[0075] This part consists of P2-delightening feed pump, E4-delightening preheater, T2-delightening tower, E5-delightening condenser, and E6-delightening reboiler.

[0076] P2 is responsible for transporting the crude liquid in V1 to E4. The outlet temperature of preheater E4 is set at 30-50℃ to appropriately increase the feed temperature.

[0077] T2 is a packed tower operated at atmospheric pressure, with packing made of stainless steel or PTFE corrugated sheets. The tower bottom is equipped with an E6 jacketed electric heater to maintain the temperature below 30°C. An E5 condenser is installed at the top of the tower, using cooling water to maintain the top temperature below 20°C. A reflux device is also provided to control the reflux ratio to no more than 1. Light components are condensed at the top of the tower and can be collected or discharged. After light components are removed, thionyl fluoride is discharged from the bottom of the tower and sent to the distillation section.

[0078] 4. Distillation and purification unit:

[0079] This section includes P3-distillation feed pump, T3-distillation tower, E7-distillation condenser, E8-distillation reboiler, P4-distillation discharge pump, and V2-liquid product tank.

[0080] T3 is a high-precision packed tower with a designed height of no less than 6 meters and multiple temperature sampling points. P3 feeds the light-removal product into the middle of the tower. The top of the tower is connected to the E7 condenser for liquefaction, with a reflux ratio controlled between 5 and 10. E8 uses hot water or thermal oil for heating, maintaining the bottom temperature between 30 and 50°C. If the bottom temperature is too high, an automatic regulating valve controls the heating rate. The high-purity thionyl fluoride product flows out of the top of the tower, liquefied, and is pumped into the V2 storage tank via the P4 pump. The bottom liquid is enriched with hydrogen fluoride and refluxes to the M1 inlet for recycling.

[0081] 5. Vaporization and boosting module:

[0082] This section consists of E9-vaporizer, V3-vaporization buffer tank, C1-compressor, and V4-high-pressure buffer tank.

[0083] E9 is a vertical shell and tube heat exchanger. The tube side passes thionyl fluoride liquid, and the shell side is heated by steam or thermal oil. The gasification outlet temperature is controlled at 50-100℃.

[0084] After a brief buffering in V3, the vaporized gas is fed into compressor C1 for pressurization. C1 is a two-stage centrifugal compressor with a designed outlet pressure of 1 to 1.5 MPa. The pressurized gas enters the V4 high-pressure buffer tank, a carbon steel cylinder lined with PTFE. This tank is equipped with a safety valve, explosion-proof membrane, and a drain port to balance pressure fluctuations and allow for the initial settling of impurities.

[0085] 6. Impurity adsorption module:

[0086] The module includes three-stage adsorption towers T4, T5 and T6, which are used to adsorb HF, HCl and residual trace impurities respectively.

[0087] T4 is filled with an HF-selective adsorbent (such as a modified molecular sieve or fluoroaluminate), T5 with an HCl adsorbent (such as alumina or molecular sieve), and T6 with high-surface-area activated carbon. The three towers are connected in series, each constructed of pressure-resistant steel and equipped with an online temperature sensor, pressure gauge, and differential pressure alarm. The lower portion of the adsorption tower is equipped with a heating and insulation layer, which allows hot air to be introduced to a temperature of 200-300°C during regeneration, achieving desorption and regeneration.

[0088] The gas is purified in sequence at T4 to T6 and then enters the next module.

[0089] 7. High-pressure gas storage and filling module:

[0090] The module includes a V5 high-pressure product tank and an automatic filling assembly. The V5 is a high-pressure storage tank with an internal coating, a design pressure of 2MPa, and is equipped with a drain port, safety valve, sampling port, and temperature control layer.

[0091] The lower portion of the tank is connected to an automatic metering and filling system, which includes a mass flow meter, electronic control valve, pressure controller, vacuum pump, and a filling tube with a standard threaded connector. The system allows for setting the fill volume, displays the filling pressure and gas volume in real time, and stores batch data for factory traceability and quality control.

[0092] 8. Control and monitoring system

[0093] The entire system is equipped with a PLC centralized control system and an industrial-grade touch screen, enabling real-time monitoring of key parameters such as flow, temperature, pressure, and liquid level. The system also features a remote alarm module with alarm prompts for temperature and pressure exceeding limits, pump failure, and adsorption tower switching. It supports manual / automatic switching modes and can be integrated into a DCS platform for higher-level management.

[0094] The electronic-grade thionyl fluoride continuous preparation and filling system provided in this embodiment has orderly connected units and precise parameter control. The purity of the prepared gas can reach over 99.999%. It is suitable for the high purity requirements of etching and cleaning gases in industries such as semiconductors and microelectronics, and has good engineering feasibility and adaptability to continuous production.

[0095] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the foregoing embodiments. The foregoing embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for the continuous preparation and filling of electronic grade thionyl fluoride, characterized in that: The method comprises the following steps: S1. Raw material mixing and preheating: anhydrous hydrogen fluoride and thionyl chloride are measured in a molar ratio of 2:1, mixed in a mixer, and the mixture is heated to 50-100° C. in a first preheater; S2, reaction and crude product separation: the mixture is fed into a reactive distillation tower, the temperature in the tower is maintained at 80-150°C, the reaction pressure is controlled at 0-0.5 MPa, the bottom liquid is refluxed by a circulating pump, the gas mixture generated during the reaction is discharged from the top of the tower, introduced into a condenser, and gas-liquid separation is performed under a cooling condition below -70°C to obtain liquid thionyl fluoride and gaseous hydrogen chloride, wherein part of the liquid thionyl fluoride is refluxed to the top of the tower, and the rest enters the crude product tank, and the gaseous hydrogen chloride is discharged through the outlet; S3, light component removal treatment: The thionyl fluoride in the crude product tank is heated to 30-50°C and transported to the light component removal tower, where the light components are removed at a temperature of 0-30°C and normal pressure. The light components escape from the top of the tower and the product flows out from the bottom of the tower; S4, distillation purification: the thionyl fluoride product after light removal is introduced into a distillation tower, separated and purified at 30-50°C, and the thionyl fluoride product with electronic grade purity requirements is extracted from the top of the tower. The reflux ratio is controlled at 5-10, part of it is refluxed to the top of the tower, and the rest flows into the product tank. The bottom liquid contains hydrogen fluoride components and is returned to the mixer to mix with new raw materials; S5. Vaporization and compression: The liquid thionyl fluoride in the product tank is fed into the vaporizer, the temperature of which is controlled at 50-100°C to generate gaseous thionyl fluoride. The gas is pressurized to 1-1.5 MPa by a compressor and introduced into a high-pressure buffer tank. S6. Impurity adsorption: The gas in the high-pressure buffer tank passes through three sets of adsorption towers in sequence, and the molecular sieve material is used to adsorb hydrogen fluoride and hydrogen chloride respectively. The towers are connected in series. The high-pressure product gas enters the high-pressure product tank after being treated in the three-stage adsorption tower; S7. Metering and filling: The gas in the high-pressure product tank is filled into the cylinder through a metering device. The filling process includes flow control and pressure regulation to complete the collection of electronic-grade thionyl fluoride products.

2. The method for continuous preparation and filling of electronic-grade thionyl fluoride according to claim 1, wherein the mass of anhydrous hydrogen fluoride pre-charged into the reactor of the reactive distillation tower is controlled to be 5-10 kg, the filling step is completed before the introduction of the raw material mixture, and the reactor bottom liquid is circulated in a closed loop between the distillation circulation pump and the reboiler to form a reflux loop to maintain the reactor bottom liquid level and reaction temperature.

3. The method for continuous preparation and filling of electronic-grade thionyl fluoride according to claim 1, wherein the condenser used in step S2 adopts a physical temperature-controlled refrigerant, the refrigerant operating temperature is lower than -70°C, the top of the condenser is provided with a gas outlet for discharging hydrogen chloride, and the bottom liquid phase outlet is connected to the crude product tank.

4. The method for continuous preparation and filling of electronic-grade thionyl fluoride according to claim 1, wherein the operating pressure of the lightness removal tower in step S3 is atmospheric pressure, a reboiler is provided in the kettle of the lightness removal tower to maintain the bottom temperature at not more than 30° C., a condenser is provided at the top of the tower for condensing light component vapor, and the reflux ratio is not higher than 1.

5. The method for continuous preparation and filling of electronic-grade thionyl fluoride according to claim 1, wherein the reflux ratio of the distillation tower is set to 5-10, a condenser connected to a reflux device is provided at the top of the tower, a reboiler is provided for heating the bottom of the tower, and the liquid at the bottom of the distillation tower is discharged to the inlet of the mixer for use in subsequent circulation reactions.

6. The method for continuous preparation and filling of electronic-grade thionyl fluoride according to claim 1, wherein the vaporizer is a shell-and-tube heat exchange device, the inlet of which is connected to a liquid product tank, the outlet of which is connected to a compressor, a heating medium is introduced into the shell side, and the temperature is adjusted within a range of 50 to 100°C; the outlet of the compressor is connected to a high-pressure buffer tank, and the buffer tank is provided with a safety valve and a sampling port.

7. The method for continuous preparation and filling of electronic-grade thionyl fluoride according to claim 1, wherein the adsorption materials in the three-stage adsorption tower are, in sequence, a hydrogen fluoride selective adsorbent, a hydrogen chloride selective adsorbent, and a residual gas adsorbent, the three groups of adsorption towers are independent cylindrical structures, and are provided with online temperature monitoring and differential pressure sensors. After adsorption saturation, the performance is restored by activation treatment at a temperature of 200-300°C.

8. A continuous preparation and filling system for electronic grade thionyl fluoride for implementing any one of the methods of claims 1 to 7, characterized in that: include: A raw material metering unit, used for proportional metering of anhydrous hydrogen fluoride and thionyl chloride; a raw material mixer, connected to the metering unit, for forming a uniform mixture; a first preheater connected to the mixer outlet; Reactive distillation tower, the top of the tower body is connected to the condenser, and the bottom of the tower is connected to the distillation circulation pump and the reboiler; a crude product tank connected to the liquid phase outlet of the condenser; The light removal tower has a feed port connected to the crude product tank and is equipped with a light removal condenser and a reboiler; The distillation tower has its feed port connected to the kettle of the light removal tower, its top connected to the condenser and reflux system, and its kettle connected to the reflux recycling pipeline; Product tank, connected to the extraction pipeline at the top of the distillation tower; The vaporizer, compressor and high-pressure buffer tank constitute the pressurization module; The adsorption tower module includes three groups of adsorption towers connected in series; High-pressure product tank, connected to the outlet of the adsorption tower module; Automatic metering and filling system for gas filling.

9. The electronic grade thionyl fluoride continuous preparation and filling system according to claim 8, wherein each adsorption tower of the adsorption tower module comprises a cylinder, a packing layer, a temperature probe, an air inlet and outlet, and a bypass valve, the adsorption tower is provided with an external insulation layer, and the adsorbent filling density is 0.4 to 0.6 g / cm 3 .

10. The electronic-grade thionyl fluoride continuous preparation and filling system according to claim 8, wherein the automatic metering and filling system comprises a flow meter, a pressure regulating valve, an anti-backflow check valve, a vacuum exhaust port, and a filling interface with a standard threaded connection, the flow meter accuracy is better than ±1%, and the pressure regulating valve has an operating range of 0.2 to 2 MPa.

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