Device and method for producing electronic grade phosphorus trifluoride and co-producing high-purity hydrogen chloride

Abstract

The invention discloses a method for co-producing high-purity hydrogen chloride from electronic-grade phosphorus trifluoride, which comprises the following steps: by taking phosphorus trichloride and hydrogen fluoride as raw materials, firstly pressurizing and feeding the phosphorus trichloride to a reaction rectifying tower kettle, then slowly introducing anhydrous hydrogen fluoride gasified by a vaporizer into the reaction rectifying tower kettle, and slowly reacting while maintaining the tower kettle temperature at a certain temperature; the generated hydrogen chloride and phosphorus trifluoride are discharged from the top of the reactive distillation tower and sent to a pre-separation tower, heavy components such as H2O are thrown out from a tower kettle, the hydrogen chloride and the phosphorus trifluoride are separated through the pre-separation tower, and then the hydrogen chloride and the phosphorus trifluoride enter a heavy component removal tower and a light component removal tower respectively and are further purified to obtain electronic-grade phosphorus trifluoride and high-purity hydrogen chloride products.

Description

Technical Field

[0001] The present invention relates to the technical field of synthesis and purification of electronic-grade special gases, and in particular to a device and method for producing electronic-grade phosphorus trifluoride and co-producing high-purity hydrogen chloride. Background Art

[0002] Electronic-grade phosphorus trifluoride, as an important high-purity chemical raw material, is widely used in fields such as semiconductors, electronics, optoelectronics, and new energy. It plays a particularly crucial role in the high-end manufacturing processes of integrated circuits, flat-panel displays, and photoresists. In the electronics industry, phosphorus trifluoride is used as a fluorinating agent for ion transfer. In semiconductor manufacturing, it can be converted into a plasma gas under the influence of microwaves for doping, improving semiconductor performance. It is also used in battery manufacturing, synthesizing polymer materials with corrosion-resistant properties, and as a catalyst in catalytic reactions. Despite strong market demand, the current industry situation indicates that the production process for electronic-grade phosphorus trifluoride is extremely demanding, making product purity and stability key. Furthermore, the current global technical barriers to entry in this field remain high.

[0003] Chinese patent CN117228643A discloses a method for preparing electronic-grade phosphorus trifluoride. Since the product after passing through the main reactor contains a certain amount of by-product fluorine chloride, the raw material conversion rate is reduced. At the same time, the generated by-products will significantly reduce the distillation efficiency of the crude phosphorus trifluoride.

[0004] Chinese patent CN101955173A discloses a technology for preparing phosphorus trifluoride by reacting phosphorus trichloride and zinc fluoride. However, the cost of synthesizing phosphorus trifluoride directly from anhydrous ZnF2 is relatively high. At the same time, the reaction has a long induction period and involves solids, which is not conducive to large-scale continuous production.

[0005] Chinese patent CN120155151A discloses a phosphorus trifluoride production device and production method, but it has the following problems: (1) The pressure of the reaction unit is low, which makes the distillation unit and the reaction unit operate discontinuously; (2) The preparation method does not disclose detailed process parameters; (3) The by-product hydrogen chloride is not purified and recovered, resulting in a waste of resources; (4) No measures are proposed to improve the reaction conversion rate, and the patent does not disclose the reaction yield index.

[0006] This patent provides a device and method for producing electronic-grade phosphorus trifluoride and co-producing high-purity hydrogen chloride, which can effectively improve the conversion rate of raw materials phosphorus trichloride and hydrogen fluoride, and can continuously produce electronic-grade phosphorus trifluoride and high-purity hydrogen chloride. Summary of the Invention

[0007] The technical solution adopted by the present invention is: a device for co-producing high-purity hydrogen chloride with electronic grade phosphorus trifluoride, comprising a phosphorus trichloride storage tank, which is sequentially connected to a phosphorus trichloride booster pump and a reaction distillation tower through a delivery pipeline; an anhydrous hydrogen fluoride cylinder is sequentially connected to a hydrogen fluoride vaporizer and a reaction distillation tower through a delivery pipeline; a reaction cooler is provided at the bottom of the reaction distillation tower, a reaction distillation tower top condenser is provided at the top; the top of the reaction distillation tower is connected to the middle of a pre-separation tower through a delivery pipeline; a pre-separation tower top condenser is provided at the top of the pre-separation tower, and a pre-separation tower bottom reboiler is provided at the bottom to ensure that the substances in the tower are not The condensation and vaporization are interrupted, the top of the pre-separation tower is connected to the middle part of the PF3 refining tower through a conveying pipeline, the top of the PF3 refining tower is provided with a PF3 refining tower top condenser, and the bottom is provided with a PF3 refining tower bottom reboiler, the bottom of the PF3 refining tower is connected to the middle part of the HCl de-weighting tower through a conveying pipeline, the top of the HCl de-weighting tower is provided with an HCl de-weighting tower top condenser, and the bottom is provided with an HCl de-weighting tower bottom reboiler, the bottom of the HCl de-weighting tower is connected to the middle part of the HCl de-lighting tower through a conveying pipeline, the top of the HCl de-lighting tower is provided with an HCl de-lighting tower top condenser, and the bottom is provided with an HCl de-lighting tower bottom reboiler.

[0008] The liquid nitrogen-thermal oil heat exchanger is connected to the thermal oil storage tank and the thermal oil booster pump in sequence through a transmission pipeline. The D12 thermal oil is cooled to -80°C by liquid nitrogen in the liquid nitrogen-thermal oil heat exchanger and then sent to the thermal oil storage tank. After being pressurized by the thermal oil booster pump, it is sent to the top condenser of the reaction distillation tower, the top condenser of the pre-separation tower, the top condenser of the PF3 refining tower, the top condenser of the HCl heavy removal tower and the top condenser of the HCl light removal tower.

[0009] Furthermore, pipelines are connected to the tail gas main pipe, vacuum main pipe and nitrogen main pipe at the top of the reaction distillation tower, pre-separation tower, PF3 refining tower, HCl heavy removal tower and HCl light removal tower respectively to ensure that all distillation towers can perform replacement operations.

[0010] Another technical solution of the present invention is to provide a method for co-producing high-purity hydrogen chloride with electronic-grade phosphorus trifluoride. Phosphorus trichloride and hydrogen fluoride are used as raw materials. The phosphorus trichloride is first pressurized and sent to the kettle of a reactive distillation tower. Anhydrous hydrogen fluoride vaporized in a vaporizer is then slowly introduced into the kettle of the reactive distillation tower. The kettle is maintained at a certain temperature for slow reaction. The generated hydrogen chloride and phosphorus trifluoride are discharged from the top of the reactive distillation tower and sent to a pre-separation tower. The kettle discards heavy components including H2O and metal ions.

[0011] Furthermore, the reaction temperature is 65-75°C. Since the reaction is an exothermic reaction, a reaction cooler is set in the kettle. 20-35% of the phosphorus trichloride level in the kettle is pumped out by a pump. The liquid in the kettle is pumped out by a circulation pump and enters the reaction cooler for heat exchange at a flow rate of 10-15L / min. After entering the reaction cooler, it is cooled to 45-50°C by cooling water and then sent back to the kettle of the reactive distillation tower to maintain a constant reaction temperature in the kettle.

[0012] Furthermore, the reaction pressure is 1.0-1.2 MPag, and a back pressure valve is provided at the top of the reactive distillation tower, with the pressure set at 1.0-1.2 MPag to ensure that the gas at the top of the tower can overcome the pressure drop and enter the subsequent distillation and purification equipment. The molar ratio of phosphorus trichloride and hydrogen fluoride reaction is 3.5:1-5:1, which increases the residence time of hydrogen fluoride gas in the phosphorus trichloride liquid phase to ensure that hydrogen fluoride can fully react and avoid bringing hydrogen fluoride into the subsequent purification and distillation equipment, causing corrosion to the equipment.

[0013] Furthermore, the condensation temperature at the top of the reactive distillation tower is -38 to -42°C to ensure that phosphorus trichloride and hydrogen fluoride are cooled into a liquid phase and refluxed into the reactor of the reactive distillation tower for circulation to participate in the reaction. Phosphorus trifluoride and hydrogen chloride are discharged from the top of the tower in a gas phase to reduce the partial pressure of the reaction products in the tower, shift the reaction equilibrium to the right, and improve the reaction rate and the conversion rate of the reactants.

[0014] Furthermore, D12 thermal oil is used as a coolant at the top of the reaction distillation tower. The D12 thermal oil is first heat-exchanged to -80°C through liquid nitrogen before entering the thermal oil storage tank. It is then pumped to the top of each distillation tower as a coolant. The flow rate of D12 is controlled by indirect heat exchange to accurately control the temperature of the top of each distillation tower.

[0015] Furthermore, the bottom of the reactive distillation tower is drained every half an hour to discharge the heavy components including H2O to prevent water from being enriched and carried into the subsequent purification and distillation equipment by gaseous phosphorus trifluoride and hydrogen chloride, causing corrosion to the equipment.

[0016] Furthermore, the reactive distillation tower has a diameter of DN50 and has two sections of PTFE Pozidriv-shaped ball ring packing, each section of packing is 2.5 m long, and a distributor is provided above each section of packing in the tower to ensure that phosphorus trichloride and phosphorus trifluoride can be fully separated.

[0017] Furthermore, the pre-separation tower has a diameter of DN80 and has three sections of regular PTFE Pozidriv ring packing, each section of which is 2.5m long. The top operating pressure is 0.9-1.0MPag, the top condenser temperature is -60~-70℃, the bottom temperature is -30~-35℃, and the molar reflux ratio is 18-21.

[0018] Furthermore, the PF3 refining tower has a diameter of DN50 and has two sections of PTFE Pozidriv ball ring packing, each section of which is 2.5m long. The top operating pressure is 0.8-0.9MPag, the top condenser temperature is -60~-70℃, the bottom temperature is -65~-75℃, and the molar reflux ratio is 13-16.

[0019] Furthermore, the HCl deweighting tower has a diameter of DN50 and has three sections of PTFE Pozidriv-shaped ball ring packing, each section of which is 2.5 m long. The top operating pressure is 0.8 MPag, the top condenser temperature is -58~-63°C, the bottom temperature is -32~-36°C, and the molar reflux ratio is 110-120.

[0020] Furthermore, the HCl light removal tower has a diameter of DN50, with a total of 3 sections of PTFE Pozidriv ring packing, each section of packing is 2.5m long, the top operating pressure is 0.7-0.8MPag, the top condenser temperature is -35~-40℃, the bottom temperature is -30~-35℃, and the molar reflux ratio is 0.15-0.18.

[0021] Furthermore, PTFE Pozidriv ball rings are used as fillers in the reaction distillation tower, pre-separation tower, PF3 refining tower, HCl heavy removal tower, and HCl light removal tower. The inner wall of the tower is sprayed with PTFE, and the pipes are lined with PTFE to ensure that the equipment is not corroded.

[0022] Furthermore, a circulating pump is provided at the bottom of the reactive distillation tower to extract the liquid from the lower part of the tower kettle and return it to the upper part of the tower kettle. On the one hand, the heat exchanger is used to control the reaction temperature in the tower kettle within 65-75°C. On the other hand, the liquid in the tower kettle is disturbed to mix the reactants evenly, prolong the reaction residence time, and enable sufficient reaction. Furthermore, the electronic-grade phosphorus trifluoride has a purity of ≥99.999%, and the key impurity contents include water ≤2.5 ppm, nitrogen ≤200 ppb, oxygen plus argon ≤300 ppb, carbon dioxide ≤400 ppb, methane ≤300 ppb, hydrogen fluoride ≤1.7 ppm, hydrogen chloride ≤1.3 ppm, AsCL3 ≤0.6 ppm, and AsF3 ≤0.5 ppm.

[0023] The present invention provides an apparatus and method for co-producing high-purity hydrogen chloride with electronic-grade phosphorus trifluoride, which has the following beneficial effects: (1) Through reactive distillation, phosphorus trichloride and hydrogen fluoride are cooled to liquid phase and refluxed to the reactor of the reactive distillation tower for circulation and reaction. Phosphorus trifluoride and hydrogen chloride are discharged from the top of the tower as gas phase to reduce the partial pressure of the reaction products in the tower, shift the reaction equilibrium to the right, and increase the reaction rate and the conversion rate of the reactants. At the same time, the recombinant water is discharged from the bottom of the tower to reduce the corrosion effect of fluoride and chloride ions on subsequent equipment. This can improve the utilization rate of raw materials and reduce equipment investment, while reducing production safety risks. (2) The purity of electronic grade phosphorus trifluoride is ≥99.999% by removing impurities such as H2O, O2, CO2, C2H2, CH4, SiH4, C2H4, AsCL3, and AsF3 from the reaction product through distillation purification.

[0024] (3) The by-product hydrogen chloride is purified to a purity greater than 99.99% through distillation, and a high-purity hydrogen chloride product is obtained by co-production. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] Figure 1 It is a schematic diagram of a part of the equipment used in the method of the present invention.

[0027] Figure 2 Schematic diagram of another part of the equipment used in the method of the present invention. In the figure: 1-phosphorus trichloride storage tank; 2-hydrogen fluoride cylinder; 3-hydrogen fluoride vaporizer; 4-liquid nitrogen-thermal oil heat exchanger; 5-thermal oil storage tank; 6-thermal oil booster pump; 7-reactive distillation column top condenser; 8-reactive distillation column; 9-bottom circulating pump; 10-reaction cooler; 11-pre-separation column top condenser; 12-pre-separation tower; 13-pre-separation column bottom reboiler; 14-PF3 refining column top condenser; 15-PF3 refining tower; 16-PF3 refining column bottom reboiler; 17-HCl de-heavy-ness removal column top condenser; 18-HCl de-heavy-ness removal column; 19-HCl de-heavy-ness removal column bottom reboiler; 20-HCl de-light-ness removal column top condenser; 21-HCl de-light-ness removal column; 22-HCl de-light-ness removal column bottom reboiler; 23-sodium hydroxide storage tank. DETAILED DESCRIPTION

[0028] like Figure 1 and Figure 2As shown, a device for co-producing high-purity hydrogen chloride with electronic grade phosphorus trifluoride includes a phosphorus trichloride storage tank 1, which is connected to a phosphorus trichloride booster pump 7 and a reaction distillation tower 8 in sequence through a delivery pipeline. An anhydrous hydrogen fluoride cylinder 2 is connected to a hydrogen fluoride vaporizer 3 and a reaction distillation tower 8 in sequence through a delivery pipeline. A reaction cooler 10 is provided at the bottom of the reaction distillation tower 8, and a reaction distillation tower top condenser 7 is provided at the top. The top of the reaction distillation tower 8 is connected to the middle of a pre-separation tower 12 through a delivery pipeline. A pre-separation tower top condenser 11 is provided at the top of the pre-separation tower 12, and a pre-separation tower bottom reboiler 13 is provided at the bottom to ensure continuous condensation and vaporization of the substances in the tower. The top of the tower 12 is connected to the middle part of the PF3 refining tower 15 through a transmission pipeline. The top of the PF3 refining tower 15 is provided with a PF3 refining tower top condenser 14, and the bottom is provided with a PF3 refining tower bottom reboiler 16. The bottom of the PF3 refining tower 15 is connected to the middle part of the HCL deweighting tower 18 through a transmission pipeline. The top of the HCL deweighting tower 18 is provided with an HCL deweighting tower top condenser 17, and the bottom is provided with an HCL deweighting tower bottom reboiler 19. The bottom of the HCL deweighting tower 18 is connected to the middle part of the HCL lightness removal tower 21 through a transmission pipeline. The top of the HCL lightness removal tower 21 is provided with an HCL lightness removal tower top condenser 20, and the bottom is provided with an HCL lightness removal tower bottom reboiler 22. The liquid nitrogen-thermal oil heat exchanger 4 is connected to the thermal oil storage tank 5 and the thermal oil booster pump 6 in sequence through a delivery pipeline. The D12 thermal oil is cooled to -80°C by liquid nitrogen in the liquid nitrogen-thermal oil heat exchanger 4 and then fed into the thermal oil storage tank 5. After being pressurized by the thermal oil booster pump 6, it is respectively fed to the top condenser 7 of the reactive distillation tower, the top condenser 11 of the pre-separation tower, the top condenser 14 of the PF3 refining tower, the top condenser 17 of the HCL degassing tower, and the top condenser 20 of the HCL degassing tower. The tops of the reactive distillation tower 8, pre-separation tower 12, PF3 refining tower 15, HCL heavy removal tower 18, and HCL light removal tower 21 are all connected to the tail gas main pipe 23, vacuum main pipe 24, and nitrogen main pipe 25 respectively, to ensure that all distillation towers can perform replacement operations.

[0029] A method for co-producing high-purity hydrogen chloride with electronic-grade phosphorus trifluoride comprises the following steps: S1. The phosphorus trichloride liquid in the phosphorus trichloride storage tank 1 is pressurized to 1.0-1.2 MPag by the phosphorus trichloride booster pump 7 and then enters the reactor of the reactive distillation tower 8. The anhydrous hydrogen fluoride is depressurized to 0.4-0.5 MPag from the anhydrous hydrogen fluoride cylinder 2 and then enters the hydrogen fluoride vaporizer 3. After being heated to 80-85° C. with hot water, it is slowly bubbled into the reactor of the reactive distillation tower 8. In the initial stage of the reaction, 120°C hot water is introduced into the shell side of the reaction cooler 10, and the phosphorus trichloride liquid in the bottom of the reactive distillation tower 8 is heated to the reaction temperature of 60-65°C before slowly introducing anhydrous hydrogen fluoride. When the reaction starts, the 120°C hot water is switched to cooling water to remove the heat generated by the reaction and maintain the bottom reaction temperature at 65-75°C. The pressure of the top back pressure valve of the reactive distillation tower 8 is set to 1.0-1.2MPag, and the top gaseous mixture PF3 and HCl enters the pre-separation tower 12 by self-pressure through the transmission pipeline, and the heavy components AsCl3 and H2O in the bottom are intermittently discharged every half hour; S2, the reaction products phosphorus trifluoride and hydrogen chloride are transported to the pre-separation tower 12 through a delivery pipeline, and are fed from the middle of the pre-separation tower. After the top gas phase is condensed by the pre-separation tower condenser 11, 93%-95% of the liquid phase is refluxed to the pre-separation tower distillation tower, and part of it enters the PF3 refining tower 15, and the non-condensable gas is discharged from the top of the tower; 32%-34% of the bottom liquid phase is reboiled in the pre-separation tower reboiler 13 and returned to the pre-separation tower, and part of it enters the HCl weight removal tower; After preliminary purification in the pre-separation tower, S3 and PF3 enter the middle position of the PF3 refining tower 15. The gas phase at the top of the tower is condensed by the PF3 refining tower condenser 14, and the liquid phase is fully refluxed into the PF3 refining tower. The non-condensable gas is discharged from the top of the tower. A part of the liquid phase at the bottom of the tower, 30%-32%, is reboiled in the PF3 refining tower reboiler 16 and returned to the PF3 refining tower. A part of it is extracted as electronic grade PF3 product. S4 and HCl are initially purified in the pre-separation tower and enter the middle position of the HCl de-weighting tower 18. The top gas phase is condensed in the HCl de-weighting tower condenser 17, and 96%-98% of the liquid phase is refluxed to the HCl de-weighting tower, and a portion enters the HCl de-lighting tower. The non-condensable gas is discharged from the top of the tower. A portion of the liquid phase at the bottom of the tower is reboiled in the HCl de-weighting tower reboiler 19 and returned to the HCl de-weighting tower, and a portion is discharged; S5, HCl is passed through the HCl de-heavy column to remove heavy components and then enters the middle position of the HCl de-light column 21. The gas phase at the top of the column is condensed by the HCl de-light column condenser 20, and the liquid phase is fully refluxed to the HCl de-light column. The non-condensable gas is discharged from the top of the column. 30%-32% of the liquid phase at the bottom of the column is reboiled in the HCl de-light column reboiler 22 and then returned to the HCl de-light column. A portion of the extracted liquid phase is high-purity HCl. S6. When an emergency stop occurs, the tops of the reactive distillation tower 8, the pre-separation tower 12, the PF3 refining tower 15, the HCl heavy removal tower 18, and the HCl light removal tower 21 are discharged to the sodium hydroxide absorption tank 23 through the tail gas line, and PF3 and HCl react and neutralize with the sodium hydroxide solution; The physical and chemical properties of industrial phosphorus trichloride are: 99.9% by mass phosphorus trichloride, 0.004% free phosphorus, and 0.2% orthophosphoric acid. The physical and chemical properties of anhydrous hydrogen fluoride are: ≥99.999% by mole fraction of hydrogen fluoride, ≤2ppm for oxygen and argon, ≤4ppm for nitrogen, ≤1ppm for carbon monoxide, ≤1ppm for carbon dioxide, ≤1ppm for sulfur dioxide, and ≤1ppm for water.

[0030] The molar purity of electronic-grade phosphorus trifluoride in the obtained product is ≥99.999%, and the key impurity contents include water ≤0.5ppm, nitrogen ≤200ppb, oxygen plus argon ≤300ppb, carbon dioxide ≤400ppb, methane ≤300ppb, hydrogen fluoride ≤1.7ppm, hydrogen chloride ≤1.3ppm, AsCl3 ≤0.6ppm, and AsF3 ≤0.5ppm.

[0031] The purity mole fraction of high-purity hydrogen chloride is ≥99.99%, and the key impurity contents include water ≤1ppm, nitrogen ≤16ppm, oxygen plus argon ≤5ppm, carbon dioxide ≤10ppm, and hydrocarbons ≤10ppm.

[0032] Example 1 Phosphorus trichloride is fed into the upper part of the reactor of the reactive distillation tower at 25°C, 3 kg / h, and 1.1 MPa. Hydrogen fluoride gas is vaporized in a hydrogen fluoride vaporizer at 25°C, 1.8 kg / h, and 1.1 MPa and then bubbled into the lower part of the reactor of the reactive distillation tower. The reaction is continued by maintaining a feed molar ratio of hydrogen fluoride:phosphorus trichloride at 4:1. The liquid in the reactor is pumped out by a circulating pump and enters a reaction cooler for heat exchange at a flow rate of 10 L / min. The liquid is heated to 45°C by low-temperature heat transfer oil and then enters the upper part of the reactor of the reactive distillation tower. The temperature and flow rate of the low-temperature heat transfer oil at the top of the tower are controlled to maintain the top temperature of -40°C and the top pressure of 1.0 MPa. The gas phase at the top of the tower is cooled by the low-temperature heat transfer oil and the liquid phase is fully refluxed into the distillation tower. The gas phase enters the middle part of the pre-separation tower at 4.5 kg / h, -40°C, and 1.0 MPa. The reactor temperature of the reactive distillation tower is maintained at 70°C, and high boiling substances at the bottom of the tower are discharged at a rate of 0.5 kg / h.

[0033] The reaction product from the reactive distillation column, at a pressure of 4.5 kg / h, -40°C, and 1.0 MPa, enters the middle section of the pre-separation column. The pre-separation column reboiler vaporizes the product at a pressure of 0.906 MPa and a temperature of -33.3°C. The reflux ratio is controlled by the pre-separation column condenser to separate phosphorus trifluoride and hydrogen chloride. The pre-separation column reboiler has a heat load of 1.5 kW. The overhead vapor from the pre-separation column, at a pressure of 22.7 kg / h, 0.9 MPa, and -60.4°C, enters the pre-separation column condenser. After cooling with low-temperature thermal oil, the non-condensable gases are discharged from the top of the heat exchanger. A portion of the liquid is refluxed to the pre-separation column, while a portion of the crude PF3 product, at a pressure of -60.4°C, 0.9 MPa, and 2 kg / h, enters the middle section of the PF3 refining column, maintaining a reflux ratio of 20. The crude HCl product, at a pressure of -33.3°C, 0.906 MPa, and 2.5 kg / h, enters the middle section of the hydrogen chloride de-weighting column.

[0034] The crude PF3 product from the pre-separation tower at -60.4°C, 0.9 MPag, and 2 kg / h enters the middle section of the PF3 refining tower. The PF3 refining tower reboiler vaporizes the material at a pressure of 0.806 MPag and a temperature of -63.3°C. The PF3 refining tower condenser controls the reflux ratio to remove non-condensable light components. The PF3 refining tower effectively removes light component impurities (Ar, O2, CO, N2, CH4, etc.). The pre-separation tower reboiler has a heat load of 0.6 kW. The overhead gas phase from the PF3 refining tower enters the PF3 refining tower condenser at 0.3 kg / h, 0.8 MPag, and -63.4°C. After cooling with low-temperature heat transfer oil, the non-condensable gases are discharged from the top of the heat exchanger, and the liquid is fully refluxed to the pre-separation tower. The bottom of the tower produces 1.8 kg / h of electronic-grade phosphorus trifluoride product with a product yield of 93%. The molar purity is ≥99.999%. Among the key impurities, water is ≤0.05 ppm, nitrogen is ≤100 ppb, oxygen plus argon is ≤100 ppb, carbon dioxide is ≤200 ppb, methane is ≤200 ppb, hydrogen fluoride is ≤1.0 ppm, hydrogen chloride is ≤1.0 ppm, AsCl3 is ≤0.5 ppm, and AsF3 is ≤0.3 ppm.

[0035] The crude HCL product at -33.3°C, 0.906MPag and 2.5kg / h from the pre-separation tower enters the middle part of the hydrogen chloride de-weighting tower. The reboiler of the hydrogen chloride de-weighting tower vaporizes the material at a pressure of 0.806MPag and a temperature of -32.4°C and controls the reflux ratio through the condenser of the hydrogen chloride de-weighting tower to discard the heavy components. The hydrogen chloride de-weighting tower can effectively remove the heavy component impurities (PCl3, HF, AsCL3, AsF3, PCl2F, etc.). The heat load of the hydrogen chloride de-weighting tower reboiler is 2.8KW. The overhead gas phase of the hydrogen chloride de-weighting tower enters the condenser of the hydrogen chloride de-weighting tower at a flow rate of 4.4 kg / h, 0.8 MPa, and -38.7°C. After being cooled by low-temperature heat transfer oil, the non-condensable gases are discharged from the top of the heat exchanger. Part of the liquid is refluxed to the hydrogen chloride de-weighting tower, and part is withdrawn to the middle of the hydrogen chloride de-lighting tower at a flow rate of 2.2 kg / h, 0.8 MPa, and -38.7°C, maintaining a reflux ratio of 0.18. High-boiling materials are discharged from the bottom of the tower.

[0036] 2.2kg / h, 0.8MPag, -38.7℃ HCl from the hydrogen chloride de-heavy tower enters the middle part of the hydrogen chloride de-light tower. The hydrogen chloride de-light tower reboiler vaporizes the material at a pressure of 0.706MPag and a temperature of -35.1℃ and controls the reflux ratio through the hydrogen chloride de-light tower condenser to throw out the light components. The hydrogen chloride de-light tower can effectively remove light component impurities (Ar, O2, CO, N2, CH4, etc.). The heat load of the hydrogen chloride de-light tower reboiler is 0.8KW. The top gas phase of the hydrogen chloride removal tower is 8.4kg / h, 0.8MPag, and -61℃, and enters the condenser of the hydrogen chloride removal tower. After cooling with low-temperature heat transfer oil, the non-condensable gas is discharged from the top of the heat exchanger, and the liquid is fully refluxed to the hydrogen chloride removal tower. The tower bottom obtains high-purity hydrogen chloride 2kg / h, and the product yield is 85%. Its purity mole fraction is ≥99.99%. Among the key impurities, water is ≤0.5ppm, nitrogen is ≤16ppm, oxygen plus argon is ≤5ppm, carbon dioxide is ≤10ppm, and hydrocarbons are ≤10ppm.

[0037] Comparative Example 1 The present application provides an apparatus and method for producing electronic-grade phosphorus trifluoride and co-producing high-purity hydrogen chloride. The apparatus and method differ from Example 1 only in that the top temperature of the reactive distillation tower is maintained at -36°C, the raw material is not fully condensed at the top of the tower, and impurities in the raw material are entrained into the subsequent distillation and purification equipment. Ultimately, 1.6 kg / h of electronic-grade phosphorus trifluoride product is obtained, with a product yield of 83% and a purity mole fraction of ≥99.995%. Among the key impurity contents, water ≤2.8 ppm, nitrogen ≤200 ppb, oxygen plus argon ≤300 ppb, carbon dioxide ≤400 ppb, methane ≤300 ppb, hydrogen fluoride ≤3.6 ppm, hydrogen chloride ≤1.7 ppm, AsCL3 ≤0.8 ppm, and AsF3 ≤2.6 ppm.

[0038] Comparative Example 2 The present application provides an apparatus and method for producing electronic-grade phosphorus trifluoride and co-producing high-purity hydrogen chloride. The apparatus and method differ from Example 1 only in that the liquid in the reactor of a reactive distillation tower is pumped out by a circulating pump and enters a reaction cooler for heat exchange. After being heated to 45° C. by low-temperature heat transfer oil, the liquid enters the upper part of the reactor of the reactive distillation tower. The flow rate is 6 L / min, the liquid in the reactor is not sufficiently disturbed, the reactants are not mixed evenly, and the reaction is not sufficient. Ultimately, 1.7 kg / h of electronic-grade phosphorus trifluoride product is obtained, the product yield is 89%, and the purity mole fraction is ≥99.995%. Among the key impurity contents, water ≤3.2 ppm, nitrogen ≤300 ppb, oxygen plus argon ≤200 ppb, carbon dioxide ≤500 ppb, methane ≤400 ppb, hydrogen fluoride ≤3.8 ppm, hydrogen chloride ≤1.4 ppm, AsCL3 ≤0.6 ppm, and AsF3 ≤2.2 ppm.

[0039] Comparative Example 3 The present application provides an apparatus and method for producing electronic-grade phosphorus trifluoride and co-producing high-purity hydrogen chloride. The only difference between the apparatus and method and Example 1 is that the liquid in the reactor of the reactive distillation tower is pumped out by a circulating pump and enters a reaction cooler for heat exchange. After being heated to 55° C. by low-temperature heat transfer oil, the liquid enters the upper part of the reactor of the reactive distillation tower at a flow rate of 10 L / min. The reaction temperature in the reactor is too high, causing the reactants to partially evaporate to the top of the tower and be carried into the subsequent distillation and purification equipment, resulting in insufficient reaction. Finally, 1.5 kg / h of electronic-grade phosphorus trifluoride product is obtained, with a product yield of 78% and a purity mole fraction of ≥99.995%. Among the key impurity contents, water ≤3.2 ppm, nitrogen ≤300 ppb, oxygen plus argon ≤200 ppb, carbon dioxide ≤500 ppb, methane ≤400 ppb, hydrogen fluoride ≤3.8 ppm, hydrogen chloride ≤1.4 ppm, AsCL3 ≤0.6 ppm, and AsF3 ≤2.2 ppm.

[0040]

[0041] Although the specific embodiments of the present invention are described above, those skilled in the art should understand that the specific embodiments described are merely illustrative and are not intended to limit the scope of the present invention. Equivalent modifications and changes made by those skilled in the art in accordance with the spirit of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A device for co-producing high-purity hydrogen chloride with electronic-grade phosphorus trifluoride, characterized in that: Including phosphorus trichloride storage tank (1), The phosphorus trichloride storage tank (1) is connected to the phosphorus trichloride booster pump (7) and the reactive distillation tower (8) in sequence through a delivery pipeline; The anhydrous hydrogen fluoride cylinder (2) is connected to the hydrogen fluoride vaporizer (3) and the reactive distillation tower (8) in sequence through a delivery pipeline; A reaction cooler (10) is provided at the bottom of the reaction distillation tower (8), and a reaction distillation tower overhead condenser (7) is provided at the top; The top of the reactive distillation tower (8) is connected to the middle of the pre-separation tower (12) through a transfer pipeline; The top of the pre-separation tower (12) is connected to the middle of the PF3 refining tower (15) through a transfer pipeline; The bottom of the PF3 refining tower (15) is connected to the middle of the HCl deweighting tower (18) through a transfer pipeline; The bottom of the HCl heavy removal tower (18) is connected to the middle of the HCl light removal tower (21) through a transfer pipeline.

2. The device for co-producing high-purity hydrogen chloride with electronic-grade phosphorus trifluoride according to claim 1, characterized in that: A pre-separation tower top condenser (11) is provided at the top of the pre-separation tower (12), and a pre-separation tower bottom reboiler (13) is provided at the bottom; The top of the PF3 refining tower (15) is provided with a PF3 refining tower top condenser (14), and the bottom of the PF3 refining tower is provided with a PF3 refining tower bottom reboiler (16); The top of the HCl de-weighting tower (18) is provided with an HCl de-weighting tower top condenser (17), and the bottom of the HCl de-weighting tower is provided with an HCl de-weighting tower bottom reboiler (19); The top of the HCl light removal tower (21) is provided with an HCl light removal tower top condenser (20), and the bottom of the HCl light removal tower is provided with an HCl light removal tower bottom reboiler (22).

3. The device for co-producing high-purity hydrogen chloride with electronic-grade phosphorus trifluoride according to claim 2, characterized in that: The device further comprises a liquid nitrogen-thermal oil heat exchanger (4), which is connected to a thermal oil storage tank (5) and a thermal oil booster pump (6) in sequence through a delivery pipeline. The heat transfer oil booster pump (6) is connected to the top condenser (7) of the reaction distillation tower, the top condenser (11) of the pre-separation tower, the top condenser (14) of the PF3 refining tower, the top condenser (17) of the HCl deheaving tower, and the top condenser (20) of the HCL deheaving tower through pipelines.

4. The device for co-producing high-purity hydrogen chloride with electronic-grade phosphorus trifluoride according to claim 2, characterized in that: The tops of the reactive distillation tower (8), pre-separation tower (12), PF3 refining tower (15), HCl heavy removal tower (18), and HCl light removal tower (21) are all provided with pipelines, which are respectively connected to the tail gas main pipe (23), the vacuum main pipe (24), and the nitrogen main pipe (25) to ensure that all distillation towers can perform the replacement operation.

5. A method for co-producing high-purity hydrogen chloride with electronic-grade phosphorus trifluoride, characterized in that: The device according to any one of claims 1 to 4 is used to pressurize phosphorus trichloride and send it to the reactor of a reactive distillation tower. Anhydrous hydrogen fluoride vaporized in a vaporizer is then slowly introduced into the reactor of the reactive distillation tower. The reactor is maintained at a certain temperature to slowly react. The generated hydrogen chloride and phosphorus trifluoride are discharged from the top of the reactive distillation tower and sent to a pre-separation tower. The heavy components including H2O are discarded from the reactor.

6. The method according to claim 5, characterized in that The reaction temperature is 65-75°C and the reaction pressure is 1.0-1.2 MPag; During the reaction, part of the phosphorus trichloride is pumped out into the reaction cooler and cooled to 45-50°C by cooling water before being sent back to the reactor of the reaction distillation tower, so that the reaction temperature in the reactor is kept constant at 65-75°C. The molar ratio of the hydrogen fluoride and phosphorus trichloride in the reaction is 3.5:1-5:

1.

7. The method according to claim 5, characterized in that The top of the reaction distillation tower uses D12 thermal oil as a coolant. The D12 thermal oil is first heat-exchanged with liquid nitrogen to -75~-80°C before entering the thermal oil storage tank and then pumped to the top of each distillation tower as a coolant.

8. The method according to claim 5, characterized in that The top condensation temperature of the reaction distillation tower is -38~-42℃. The diameter of the reaction distillation tower (8) is DN50. There are two sections of PTFE ball ring packing. A distributor is set above each section of packing in the tower to ensure that phosphorus trichloride and phosphorus trifluoride can be fully separated.

9. The method according to claim 5, characterized in that The pre-separation tower (12) has a diameter of DN80 and has three sections of PTFE Pozidriv-shaped ball ring packing. The top operating pressure is 0.9-1.0 MPag, the top condenser temperature is -60~-70°C, the bottom temperature is -30~-35°C, and the molar reflux ratio is 18-21.

10. The method according to claim 5, characterized in that The PF3 refining tower (15) has a diameter of DN50 and has two sections of PTFE Pozidriv-shaped ball ring packing. The top operating pressure is 0.8-0.9 MPag, the top condenser temperature is -60~-70°C, the bottom temperature is -65~-75°C, and the molar reflux ratio is 13-16.

11. The method according to claim 5, characterized in that The HCL deweighting tower (18) has a diameter of DN50 and has three sections of PTFE ball ring packing. The operating pressure at the top of the tower is 0.8 MPag, the temperature of the top condenser is -58~-63°C, the temperature of the bottom of the tower is -32~-36°C, and the molar reflux ratio is 110-120.

12. The method according to claim 5, characterized in that The HCL light removal tower (21) has a diameter of DN50 and has three sections of PTFE ball ring packing. The top operating pressure is 0.7-0.8 MPag, the top condenser temperature is -35--40°C, the bottom temperature is -30--35°C, and the molar reflux ratio is 0.15-0.

18.

13. The method according to claim 5, wherein The reactive distillation tower (8), pre-separation tower (12), PF3 refining tower (15), HCL de-heavy tower (18), and HCL de-light tower (21) are filled with PTFE Pozidriv ball rings, the tower inner wall is sprayed with PTFE, and the pipeline is lined with PTFE to ensure that the equipment is not corroded.

14. The method according to claim 5, characterized in that The bottom of the reaction distillation tower (8) is provided with a circulation pump to extract the liquid in the lower part of the tower kettle and return it from the upper part of the tower kettle. On the one hand, the heat exchanger is used to control the reaction temperature in the tower kettle to be within 65-75°C. On the other hand, the liquid in the tower kettle is disturbed to mix the reactants evenly, prolong the reaction residence time, and enable a full reaction.

15. The method according to any one of claims 5 to 14, characterized in that: The obtained electronic grade phosphorus trifluoride has a purity of ≥99.999%, and the impurity content includes water ≤0.5ppm, nitrogen ≤200ppb, oxygen plus argon ≤300ppb, carbon dioxide ≤400ppb, methane ≤300ppb, hydrogen fluoride ≤1.7ppm, hydrogen chloride ≤1.3ppm, AsCL3 ≤0.6ppm, and AsF3 ≤0.5ppm; And / or, the purity of the by-product hydrogen chloride is greater than 99.99%, and the impurity content of water is ≤1 ppm, nitrogen is ≤16 ppm, oxygen plus argon is ≤5 ppm, carbon dioxide is ≤10 ppm, and hydrocarbons are ≤10 ppm.

16. A method for co-producing high-purity hydrogen chloride with electronic-grade phosphorus trifluoride, characterized in that: The steps include: S1. The phosphorus trichloride liquid in the phosphorus trichloride storage tank (1) is pressurized to 1.0-1.2 MPag by the phosphorus trichloride booster pump (7) and then enters the reactor of the reaction distillation tower (8). The anhydrous hydrogen fluoride is depressurized to 0.4-0.5 MPag from the anhydrous hydrogen fluoride cylinder (2) and then enters the hydrogen fluoride vaporizer (3). After being heated to 80-85°C with hot water, it is slowly bubbled into the reactor of the reaction distillation tower (8). In the initial stage of the reaction, 110-120°C hot water is introduced into the shell of the reaction cooler (10). The phosphorus trichloride liquid in the bottom of the reaction distillation tower (8) is heated to a reaction temperature of 60-65°C and then anhydrous hydrogen fluoride is slowly introduced. When the reaction starts, the hot water is switched to cooling water to remove the heat generated by the reaction and maintain the bottom reaction temperature at 65-75°C. The pressure of the top back pressure valve of the reaction distillation tower (8) is set to 1.0-1.2MPag. The top gas phase mixture PF3 and HCl enters the pre-separation tower (12) through the transmission pipeline under self-pressure. The heavy components AsCl3 and H2O in the bottom are intermittently discharged every half hour. S2, the reaction products phosphorus trifluoride and hydrogen chloride are transported to the pre-separation tower (12) through a transport pipeline, and are fed from the middle of the pre-separation tower. After the gas phase at the top of the tower is condensed by the pre-separation tower condenser (11), part of the liquid phase is refluxed into the pre-separation tower distillation tower, and part of it enters the PF3 refining tower. The non-condensable gas is discharged from the top of the tower, and part of the liquid phase at the bottom of the tower is reboiled by the pre-separation tower reboiler (13) and returned to the pre-separation tower, and part of it enters the HCl de-weighting tower; After preliminary purification in the pre-separation tower, S3 and PF3 enter the middle position of the PF3 refining tower (15). The gas phase at the top of the tower is condensed by the PF3 refining tower condenser (14) and the liquid phase is fully refluxed into the PF3 refining tower. The non-condensable gas is discharged from the top of the tower. A part of the liquid phase at the bottom of the tower is reboiled by the PF3 refining tower reboiler (16) and returned to the PF3 refining tower. A part of it is extracted as electronic grade PF3 product. S4 and HCl are initially purified in the pre-separation tower and enter the middle position of the HCl de-weighting tower (18). The gas phase at the top of the tower is condensed in the HCl de-weighting tower condenser (17). A portion of the liquid phase flows back to the HCl de-weighting tower, and a portion flows into the HCl de-lighting tower. Non-condensable gas is discharged from the top of the tower. A portion of the liquid phase at the bottom of the tower is reboiled in the HCl de-weighting tower reboiler (19) and returns to the HCl de-weighting tower, and a portion is discharged. S5, HCl is passed through the HCl de-heavy tower to remove heavy components and then enters the middle position of the HCl de-light tower (21). The gas phase at the top of the tower is condensed by the HCl de-light tower condenser (20), and the liquid phase is fully refluxed into the HCl de-light tower. The non-condensable gas is discharged from the top of the tower. A part of the liquid phase at the bottom of the tower is reboiled by the HCl de-light tower reboiler (22) and then returned to the HCl de-light tower. A part of the liquid phase is extracted as high-purity HCl. S6. When an emergency stop occurs, the tops of the reaction distillation tower (8), pre-separation tower (12), PF3 refining tower (15), HCl heavy removal tower (18), and HCl light removal tower (21) are discharged into the sodium hydroxide absorption tank (23) through the tail gas pipeline, and PF3 and HCl react with the sodium hydroxide solution to neutralize.

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