Process for the rectification and purification of high purity phosphoranes

Abstract

This invention discloses a distillation purification process for high-purity phosphine, belonging to the field of purification technology. The process comprises three main modules: pretreatment, core deep purification, and post-treatment support. The pretreatment module removes most water, sulfur impurities, and light components from crude phosphine through three-stage cryogenic treatment and modified activated carbon adsorption. The core module employs a 193nm ArF excimer laser to dissociate arsine, combined with adsorption using a specialized metal-organic framework material and a non-evaporative getter to achieve deep removal of trace impurities. The post-treatment module ensures process stability through online monitoring and PLC adaptive closed-loop control. The process can produce 7N-8N grade high-purity phosphine with compliant levels of key impurities such as arsine, achieving a yield ≥95%. It is suitable for large-scale production and contributes to the domestic production of electronic specialty gases.

Description

Technical Field

[0001] This invention relates to the field of purification technology, and more specifically, to a distillation purification process for high-purity phosphine. Background Technology

[0002] Phosphine, as a key electronic specialty gas, is an important n-type dopant source in core processes such as semiconductor ion implantation and chemical vapor deposition. Its purity directly determines device performance and yield. Advanced processes require phosphine purity at the 7N-8N level, with extremely stringent control over trace impurities such as arsine, moisture, and metal impurities. Currently, crude phosphine synthesis processes mostly involve yellow phosphorus disproportionation and acid hydrolysis of metal phosphides. The limitations in raw material purity result in crude phosphine containing various impurities such as water vapor, hydrogen sulfide, arsine, carbon dioxide, light components, and metal particles.

[0003] Existing purification processes mostly employ single distillation or adsorption methods, which have significant drawbacks: traditional distillation struggles to separate impurities with similar properties, such as arsine and phosphine; adsorbents exhibit poor selectivity, are prone to saturation, and lack effective closed-loop control mechanisms, resulting in large fluctuations in product purity, low yields, and difficulty in consistently achieving levels above 7N. Furthermore, existing processes suffer from high energy consumption, difficulties in adsorbent regeneration, and incomplete impurity removal. High-end, high-purity phosphine remains heavily reliant on imports, hindering the independent and controllable development of my country's semiconductor industry. Therefore, developing an efficient, stable, and scalable high-purity phosphine purification process to address the issues of deep removal of trace impurities and process stability has become an urgent need in the field of electronic specialty gases. Summary of the Invention

[0004] In order to overcome the problems of incomplete removal of process impurities, low product purity, poor yield, insufficient process stability, and difficulty in large-scale production in the existing technology, this invention discloses a distillation purification process for high-purity phosphine that can effectively solve the above-mentioned technical problems.

[0005] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows: A distillation purification process for high-purity phosphine, wherein the purification process sequentially includes a pretreatment module, a core deep purification module, and a post-support module; In the pretreatment module, the crude phosphine is subjected to cryogenic pre-dehydration, modified activated carbon adsorption desulfurization, and cryogenic removal of light components in sequence. In the core deep purification module, a 193nm ArF excimer laser is used to selectively photodissociate arsine in the gas phase stream, generating elemental arsenic particles, which are then captured by a metal oxide trap. Residual arsine is then selectively adsorbed using an amino-functionalized UiO-66-NH2 metal-organic framework material. Carbon dioxide is then selectively adsorbed using a Zn-MOF-74 metal-organic framework material. Finally, oxygen and water are deeply removed using a Zr-V-Fe non-evaporative metal getter. The post-support module includes an online impurity monitoring system and an adaptive feedback control system based on a programmable logic controller to achieve closed-loop adjustment of process parameters.

[0006] Furthermore, it includes the following steps: S1: Preprocessing; S11: Crude phosphine is introduced into a three-stage series spiral tube cryogenic cold trap, with the temperatures of each stage set to -60℃, -80℃ and -100℃, respectively, to remove water vapor and carbon dioxide. S12: The phosphine gas treated by S11 is passed into an adsorption tower filled with modified activated carbon to remove hydrogen sulfide and organic sulfur impurities at room temperature. S13: The phosphine gas treated by S12 is passed into a spiral tube heat exchanger at -160℃ to remove nitrogen, oxygen, argon and light methane impurities to obtain pretreated phosphine. S2: Core deep purification; S21: The pretreated phosphine prepared in S13 is introduced into the laser-induced dissociation reaction chamber at a controlled flow rate and irradiated with a 193nm ArF excimer laser with a laser pulse frequency of 50-200Hz and a single pulse energy of 50-200mJ to selectively photodissociate the arsenane into elemental arsenic particles. S22: The gas treated by S21 is passed into a metal oxide collector filled with a CuO / Al2O3 composite bed, and the elemental arsenic particles are oxidized and collected into As2O3 at 250℃. S23: The gas treated by S22 is passed into an adsorption tower filled with UiO-66-NH2 metal-organic framework material, and residual arsenic is selectively adsorbed at -40℃ and 1.5 bar. S24: The gas treated by S23 is passed into an adsorption tower filled with Zn-MOF-74 metal-organic framework material, and carbon dioxide is selectively adsorbed at 25℃ and 2.0 bar. S25: The gas treated by S24 is passed into a purifier filled with Zr-V-Fe non-evaporable getter, and oxygen and water are deeply removed at 350℃ activation and 350℃ operating temperature. S3: Rear protection; S31: Online impurity monitoring points are set at the outlets of the laser dissociation reaction chamber S21, S23, S24 and S25. The concentrations of phosphine, arsine, carbon dioxide and water are detected by Fourier transform infrared spectroscopy, and the concentrations of metal impurities are detected by gas chromatography-inductively coupled plasma mass spectrometry. S32: The real-time detection data of S31 is collected by the programmable logic controller and uploaded to the central control unit. When the arsine concentration exceeds 0.05 ppb, the programmable logic controller automatically adjusts the laser pulse frequency, single pulse energy and gas residence time. When the impurity concentration at the outlet of the adsorption tower reaches the penetration threshold, the control system automatically switches to the standby adsorption tower and switches the saturated adsorption tower to the online thermal regeneration mode. S33: The gas treated by S25 is passed into a series-connected nanoporous filter assembly, and filtered sequentially through a 0.1μm ceramic membrane and a carbon molecular sieve membrane with a pore size of 5Å to remove metal particles and obtain a high-purity phosphine product.

[0007] Furthermore, the diameter of the three-stage series spiral tube cryogenic cold trap described in S11 is 10mm, the pitch is 30mm, and the total length of a single-stage tube is 5m; the flow rate of the crude phosphine and the gas-liquid ratio of the heat exchange area of ​​the cold trap are controlled between 100:1 and 500:1.

[0008] Furthermore, the operating space velocity of the modified activated carbon adsorption tower described in S12 is 200-500 h⁻¹. -1 The operating pressure is 1.0 bar; the modified activated carbon is obtained by impregnation with 5-10 wt% potassium hydroxide solution and then calcination at 400℃ under nitrogen atmosphere for 2-4 hours.

[0009] Further, the preparation method of the UiO-66-NH2 metal-organic framework material described in S23 is as follows: zirconium chloride and 2-aminoterephthalic acid are dissolved in N,N-dimethylformamide in a molar ratio of 1:1 to 1:2, acetic acid is added as a regulator, and the mixture is hydrothermally reacted at 120°C for 24 h. After centrifugation, the mixture is washed successively with N,N-dimethylformamide and methanol, and then vacuum dried at 80°C for 12 h to obtain the UiO-66-NH2 crystal material.

[0010] Further, the preparation method of the Zn-MOF-74 metal-organic framework material described in S24 is as follows: Zinc nitrate hexahydrate and 2,5-dihydroxyterephthalic acid are dissolved in a mixed solvent of N,N-dimethylformamide, ethanol and water in a molar ratio of 2:1 to 4:1, and the mixture is hydrothermally reacted at 120°C for 48 h. After filtration, the mixture is washed with N,N-dimethylformamide and methanol, and activated under vacuum at 150°C for 12 h to obtain the Zn-MOF-74 material. After the Zn-MOF-74 material is saturated with adsorption, it is regenerated by purging with nitrogen gas at 120°C and a vacuum of 10-50 mbar, and the number of cycles is ≥500.

[0011] Furthermore, the activation conditions for the Zr-V-Fe non-evaporable getter described in S25 are: 350°C and a vacuum degree <10. - 3Heating at Pa for 30 minutes; the mass fraction of each metal in the getter is: zirconium 65-75%, vanadium 20-30%, iron 3-10%.

[0012] Furthermore, the operating conditions of the online thermal regeneration mode described in S32 are as follows: nitrogen is used as the purge gas, the purge flow rate is 50-200 mL / min, the system pressure is 10-50 mbar, the heating temperature is 200-350℃, and the holding time is 2-6 h.

[0013] Furthermore, the process also includes a three-stage metal getter purifier at the end of the core deep purification module. The first stage is a Zr-V-Fe non-evaporable getter, the second stage is a getter deposited on a porous metal substrate with a thickness of 1-5 μm using magnetron sputtering technology, with an operating temperature of 250℃, and the third stage is a Pd / Ag alloy membrane separator with a membrane thickness of 10 μm, an operating temperature of 400℃, and a pressure difference of 0.5-2.0 bar, used to remove hydrogen impurities and recover the hydrogen-rich gas from the permeation side for use as fuel.

[0014] Furthermore, the high-purity phosphine product produced by the process has a purity of 7N-8N, wherein the content of arsine is <0.01ppb, the content of carbon dioxide is <0.1ppm, the content of oxygen is <0.01ppm, the content of water is <0.01ppm, and the total content of metal ions is <0.1ppb; the phosphine yield is ≥95%.

[0015] Compared with existing technologies, the beneficial effects of this invention are as follows: This process achieves highly efficient purification of crude phosphine through the synergistic cooperation of pretreatment, core deep purification, and post-processing support modules, resulting in significant overall benefits. The combination of pretreatment with three-stage cryogenic treatment and modified activated carbon adsorption efficiently removes most moisture, sulfur impurities, and light components, laying the foundation for subsequent deep purification, reducing the processing load of the core module, and improving overall process efficiency. The core module employs laser dissociation in conjunction with specialized adsorbents and getters to specifically address the problem of difficult-to-remove impurities such as arsine. The 193nm ArF excimer laser selectively dissociates arsine, and combined with specialized materials such as UiO-66-NH2, it adsorbs residual impurities, achieving a removal accuracy far exceeding traditional processes. The well-designed post-processing support system, combining online multi-point monitoring with PLC adaptive feedback control, allows for real-time adjustment of process parameters, automatic switching of adsorption towers, and regeneration, ensuring stable and controllable product purity and avoiding batch fluctuations. The specialized adsorbents and getters are recyclable; Zn-MOF-74 can be recycled ≥500 times, significantly reducing production costs. The final three-stage purification and filtration components further remove hydrogen and metal particles, achieving a final product purity of 7N-8N. All impurity indicators meet the requirements of high-end applications, with a phosphine yield of ≥95%. This process enables large-scale production while reducing energy consumption. This process eliminates the need for high-pressure operation, ensuring higher safety, breaking the dependence on imported high-purity phosphine, promoting the localization of electronic specialty gases, and contributing to the high-quality development of the semiconductor industry. Attached Figure Description

[0016] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely exemplary. For those skilled in the art, other embodiments can be derived from the provided drawings without creative effort.

[0017] Figure 1 A flowchart of a high-purity phosphine distillation purification process provided for embodiments of this application. Detailed Implementation

[0018] The accompanying drawings are for illustrative purposes only and should not be construed as limiting the scope of this patent. To better illustrate this embodiment, some parts in the accompanying drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions; It will be understood by those skilled in the art that certain well-known structures and their descriptions may be omitted in the accompanying drawings.

[0019] The embodiments of this application will be further described in detail below with reference to the accompanying drawings and examples.

[0020] It is understood that the specific embodiments described herein are merely illustrative of the embodiments of this application and are not intended to limit the embodiments of this application. Furthermore, it should be noted that, for ease of description, the accompanying drawings only show the parts related to the embodiments of this application, not all structures. Those skilled in the art, after reading this specification, should be able to realize that any combination of technical features can constitute an optional implementation method, provided that the technical features do not contradict each other.

[0021] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship. In the description of this application, "multiple" means two or more, and "several" means one or more.

[0022] This invention discloses a distillation purification process for high-purity phosphine, aiming to solve the technical problems in existing high-purity phosphine purification processes, such as incomplete impurity removal, unstable product purity, low yield, and difficulty in large-scale production. It achieves efficient and stable preparation of 7N-8N grade high-purity phosphine, meeting the application requirements of high-purity phosphine in high-end fields such as semiconductors and solar photovoltaic cells. The following detailed and complete disclosure of the technical solution of this invention, in conjunction with specific embodiments, enables those skilled in the art to fully understand and implement this invention.

[0023] It should be noted that, unless otherwise specified, the equipment, materials, reagents, etc. involved in this embodiment are all commercially available conventional products; the operating steps and process parameters involved are all optimized selections based on the technical solution of this invention, and can be appropriately adjusted according to the actual production scale, raw material purity, etc., and all fall within the protection scope of this invention. In this embodiment, "room temperature" refers to 25±5℃, "bar" is a unit of pressure, 1 bar = 100 kPa, "ppb" is one part per billion, "ppm" is one part per million, and "7N-8N grade" refers to phosphine purity of 99.99999%-99.999999%.

[0024] This high-purity phosphine distillation purification process adopts a modular design, comprising a pretreatment module, a core deep purification module, and a post-purification support module. These three modules work synergistically to remove various impurities from the crude phosphine in stages, ultimately yielding a high-purity phosphine product. The pretreatment module primarily removes most easily treated impurities from the crude phosphine, reducing the processing load on the subsequent core module. The core deep purification module removes trace amounts of difficult-to-remove impurities and is crucial for ensuring product purity. The post-purification support module monitors the process in real time and adjusts process parameters to ensure stable process operation and product quality compliance.

[0025] Please see Figure 1 The overall process flow is as follows: crude phosphine raw material - pretreatment module (deep cryogenic pre-dehydration - modified activated carbon adsorption desulfurization - deep cryogenic removal of light components) - core deep purification module (laser selective photodissociation of arsine - elemental arsenic capture - residual arsine adsorption - carbon dioxide adsorption - deep removal of oxygen and water - hydrogen removal and recovery) - post-support module (online impurity monitoring - adaptive feedback adjustment - metal particle filtration) - storage and transportation of high-purity phosphine products.

[0026] This process is suitable for purifying various crude phosphine raw materials, including crude phosphine synthesized by methods such as yellow phosphorus disproportionation and metal phosphide acid hydrolysis. The crude phosphine raw materials contain ≥90% phosphine, and the main impurities include water vapor, carbon dioxide, hydrogen sulfide, organic sulfur, nitrogen, oxygen, argon, methane, arsine, hydrogen, and metal particles. After purification by this process, the purity of phosphine can reach 7N-8N level, and all impurity indicators meet the requirements of high-end applications. Moreover, the phosphine yield is ≥95%, enabling large-scale continuous production.

[0027] The core purpose of the pretreatment module is to remove most of the easily removable impurities from the crude phosphine, including water vapor, carbon dioxide, sulfur-based impurities (hydrogen sulfide, organic sulfur), and light components (nitrogen, oxygen, argon, methane). This provides qualified pretreated phosphine for the subsequent core deep purification module, preventing impurities from contaminating or affecting the performance of the core module's adsorbent, getter, and laser dissociation system. The specific implementation steps of this module are as follows: S1: Pre-treatment Preparation. Before starting the pre-treatment module, equipment checks, parameter adjustments, and raw material preparation must be completed to ensure smooth process operation: Check the integrity of equipment such as the three-stage series spiral tube cryogenic cold trap, modified activated carbon adsorption tower, and spiral tube heat exchanger to ensure no leaks, normal operation of each heating and cooling system, and temperature control accuracy of ±1℃; preset the temperatures of the three-stage cold trap to -60℃, -80℃, and -100℃ respectively, the spiral tube heat exchanger to -160℃, the modified activated carbon adsorption tower operating pressure to 1.0 bar, and the space velocity to 200-500 h⁻¹. -1Select crude phosphine raw material (phosphine 92%-95%, containing various impurities), store it in a high-pressure storage tank (pressure 5.0-8.0 bar), and adjust the outlet pressure to 1.2-1.5 bar via a pressure reducing valve for later use.

[0028] S11: Cryogenic Pre-Dehydration Treatment. This step employs a three-stage series-connected spiral tube cryogenic cold trap. Water vapor and most of the carbon dioxide are removed from the crude phosphine through gradient cryogenic treatment, utilizing the fact that their condensation temperatures are higher than those of the phosphine to achieve separation. All three cold traps are made of 316L stainless steel, with each stage having a tube diameter of 10mm, a pitch of 30mm, a total tube length of 5m per stage, and a single-stage heat exchange area of ​​0.471m². 2 The total heat exchange area is 1.413m². 2 It is equipped with a spiral coil inside to enhance heat exchange, and a drain outlet at the bottom to discharge condensate.

[0029] During operation, crude phosphine is introduced into a three-stage cold trap at a stable flow rate, sequentially undergoing gradient cooling at -60℃, -80℃, and -100℃. Most of the water vapor and carbon dioxide gradually condense into liquid or solid states. Key parameter control: The gas-liquid ratio of crude phosphine flow rate to the cold trap heat exchange area is 100:1 to 500:1, preferably 300:1 (corresponding to a flow rate of 423.9 m³ / s). 3 ( / h, standard conditions) Ensure sufficient gas residence time to remove water vapor to ≤100ppm and carbon dioxide to ≤50ppm. During operation, temperature must be monitored in real time, condensate drained every 2-4 hours, and the cold trap thawed and cleaned every 72 hours to restore heat exchange performance.

[0030] S12: Modified activated carbon adsorption desulfurization treatment. This step uses modified activated carbon adsorbent to remove hydrogen sulfide and organic sulfur impurities from the gas treated by S11 at room temperature. Preparation of modified activated carbon: Select 2-5mm granular activated carbon (specific surface area ≥1000m²). 2 / g), soak in 5-10wt% potassium hydroxide solution (preferably 7wt%) at a liquid-solid ratio of 3:1 for 24h, wash until neutral, dry at 80℃ for 12h, and then calcine at 400℃ under nitrogen atmosphere (flow rate 50mL / min) for 2-4h (preferably 3h), cool and seal for later use.

[0031] The adsorption tower is made of 316L stainless steel, with a diameter of 500mm and a height of 3000mm. It is packed with 500kg of modified activated carbon, with a bed height of 2000mm. A gas distributor is installed at the top to ensure uniform gas contact. During operation, the gas is supplied at a pressure of 1.0 bar for 200-500 hours. -1 Airspeed (preferably 350 h) -1The modified activated carbon is fed into the adsorption tower, where it selectively adsorbs sulfur-based impurities through physical adsorption and chemical action, ensuring that the outlet hydrogen sulfide concentration is ≤0.1ppm and organic sulfur concentration is ≤0.05ppm. The concentrations of sulfur-based impurities at the inlet and outlet are monitored in real time. When the adsorbent is close to saturation, a backup tower is switched on. The saturated adsorbent can be thermally regenerated and reused, with a service life of ≥1000h.

[0032] S13: Cryogenic Removal of Light Components. This step uses a spiral tube heat exchanger to remove light components such as nitrogen, oxygen, argon, and methane at -160℃, utilizing the fact that the boiling points of these light components are lower than those of phosphine to achieve separation. The heat exchanger is made of 316L stainless steel, with a tube diameter of 15mm, a screw pitch of 40mm, a total tube length of 10m, and a heat exchange area of ​​1.884m². 2 It uses liquid nitrogen as the refrigerant and has a drain port on the side to discharge condensed impurities.

[0033] During operation, the gas treated by S12 is introduced into the heat exchanger, with the temperature strictly controlled at -160℃ (deviation ±2℃). The gas residence time is 10-15s (preferably 12s). Light components condense into liquid or solid states, while phosphine remains in a gaseous state for separation. Pre-treated phosphine must meet the following requirements: phosphine content ≥99.5%, total light component content ≤0.5%, water vapor ≤100ppm, carbon dioxide ≤50ppm, and sulfur impurities must meet standards to ensure compliance with the feeding requirements of subsequent core modules. During operation, proper insulation (50mm polyurethane insulation layer) is required, and condensed impurities should be discharged every 1-2 hours to minimize cooling loss.

[0034] The core deep purification module is the key component of this process, used to remove trace, difficult-to-remove impurities from pretreated phosphine, including arsine, residual carbon dioxide, oxygen, water, and hydrogen. Through laser dissociation, adsorption with a specialized adsorbent, getter removal, and hydrogen recovery, it ensures that the product purity reaches the 7N-8N level. The specific implementation steps are as follows: S2: Core Deep Purification Preparation. Before startup, equipment checks, material preparation, and parameter adjustments must be completed: Check the integrity of equipment such as the laser-induced dissociation reaction chamber and metal oxide trap to ensure no leaks; prepare UiO-66-NH2 and Zn-MOF-74 materials in advance, and activate Zr-V-Fe and Ti-Zr-V getters; preset the parameters of each device: metal oxide trap 250℃, UiO-66-NH2 adsorption tower -40℃, 1.5 bar, Zn-MOF-74 adsorption tower 25℃, 2.0 bar, Zr-V-Fe purifier 350℃, secondary getter 250℃, Pd / Ag alloy membrane separator 400℃, pressure difference 1.2 bar, and preset the laser parameters as pulse frequency 125Hz and single pulse energy 125mJ. These parameters should be stabilized before use.

[0035] S21: Laser-Selective Photodissociation of Arsine. This step uses a 193nm ArF excimer laser, utilizing the characteristic absorption of this wavelength of laser light by arsine to selectively dissociate it into elemental arsenic particles, while the phosphine remains stable. The laser-induced dissociation reaction chamber is made of quartz, with an inner diameter of 200mm and a length of 1000mm, equipped with a gas distributor and a quartz laser window; the laser output power is 10-20W, the pulse frequency is 50-200Hz, the single pulse energy is adjustable from 50-200mJ, the laser beam diameter is 10mm, and the angle between the laser beam and the gas flow is 90°.

[0036] During operation, pretreatment of phosphine is carried out at 100-300m 3 / h (preferably 200m) 3 A pulse of acetylene is introduced into the reaction chamber at a rate of 125 Hz and 125 mJ, with a residence time of 5-10 s (preferably 7 s). The laser is then activated. The preferred parameters are 125 Hz and 125 mJ. The arsine dissociation reaction is: AsH3 + hν (193 nm) → As 0 + 3H·, dissociation efficiency ≥99%, phosphine dissociation rate ≤0.1%. During operation, laser parameters and gas flow rate need to be monitored in real time, the laser window needs to be cleaned regularly, and the reaction chamber needs to be cleaned every 72 hours to ensure laser penetration efficiency and reaction effect.

[0037] S22: Collection and treatment of elemental arsenic particles. This step uses a CuO / Al2O3 composite bed metal oxide collector to oxidize and collect elemental arsenic particles into As2O3 at 250℃. Composite bed preparation: CuO and Al2O3 are mixed at a mass ratio of 1:4, water is added to form columnar particles, calcined at 500℃ for 4 hours, cooled, and then packed into the collector (316L stainless steel, tower diameter 400mm, tower height 2500mm), with a packing amount of 300kg and a bed height of 1500mm.

[0038] During operation, the gas treated by S21 is at a speed of 200m 3 The gas is introduced into the collector at a rate of / h, with a residence time of 8-12s (preferably 10s). Elemental arsenic reacts with CuO in an oxidation reaction: 4As 0 + 3CuO + 3H2O → 2As2O3 + 3Cu + 3H2↑, As2O3 is adsorbed and fixed by Al2O3. The temperature is controlled at 250℃, and the concentration of elemental arsenic at the outlet is monitored in real time. When it exceeds 0.01ppb, the composite adsorbent is replaced. The captured As2O3 must be properly disposed of to avoid environmental pollution.

[0039] S23: Residual Arsenic Adsorption Treatment. This step uses UiO-66-NH2 metal-organic framework material to selectively adsorb residual arsenic at -40℃ and 1.5 bar, ensuring arsenic ≤0.01 ppb. Material preparation: Zirconium chloride and 2-aminoterephthalic acid are dissolved in N,N-dimethylformamide (DMF) at a molar ratio of 1:1 to 1:2 (preferably 1:1.5). 10% volumetric acetic acid is added as a regulator, and the mixture is hydrothermally reacted at 120℃ for 24 h. After centrifugation, the mixture is washed three times with DMF and methanol, and then vacuum dried at 80℃ for 12 h to obtain a crystalline material (specific surface area ≥1200 m²). 2 / g), sealed for later use. Its performance advantage stems from the synergistic effect of pore structure and functionalization. The pore size of 0.5-1.0nm enables molecular sieving, while the amine functional groups provide chemisorption. The combination of these two factors multiplies the selectivity of arsine.

[0040] The adsorption tower is made of 316L stainless steel, with a diameter of 400mm and a height of 2500mm. It is packed with 400kg of UiO-66-NH2, with a bed height of 1800mm, and is equipped with a liquid nitrogen cooling and pressure control system. During operation, the gas flow rate is 200m³ / h. 3 The adsorbent is introduced at a rate of / h, with a residence time of 10-15s (preferably 12s). The amino group forms a stable complex with the residual arsine to achieve adsorption. The outlet arsine concentration is monitored in real time. If it exceeds 0.01ppb, the standby tower is switched on. The saturated adsorbent can be reused after thermal regeneration, with a service life of ≥800h.

[0041] S24: Carbon Dioxide Adsorption Treatment. This step uses Zn-MOF-74 metal-organic framework material to adsorb residual carbon dioxide at 25℃ and 2.0 bar, ensuring a content ≤0.1ppm. Material preparation: Zinc nitrate hexahydrate and 2,5-dihydroxyterephthalic acid are dissolved in a mixed solvent of DMF, ethanol, and water (volume ratio 3:1:1) at a molar ratio of 2:1 to 4:1 (preferably 3:1). The mixture is hydrothermally reacted at 120℃ for 48 hours, filtered, washed, and then vacuum activated at 150℃ for 12 hours to obtain the material (specific surface area ≥1500m²). 2 / g), sealed for later use. Its unique pore structure (0.4-0.8nm) and metallic active sites give it a strong selective adsorption capacity for carbon dioxide, excellent cycle stability, and a high adsorption capacity retention rate in multiple tests.

[0042] The adsorption tower is made of 316L stainless steel, with a diameter of 400mm and a height of 2500mm. It is packed with 450kg of Zn-MOF-74, and the bed height is 2000mm. During operation, the gas flow rate is 200m³ / h. 3The adsorption rate is 8-12 seconds (preferably 10 seconds) per hour, achieving efficient adsorption at room temperature. The outlet carbon dioxide concentration is monitored in real time; if it exceeds 0.1 ppm, a backup tower is switched on. The saturated material is regenerated by nitrogen purging at 120℃ and 10-50 mbar vacuum, allowing for ≥500 cycles.

[0043] S25: Deep removal of oxygen and water. This step uses a Zr-V-Fe non-evaporative getter to deeply remove oxygen and water at 350℃, ensuring that both are ≤0.01ppm. The getter is a commercially available flaky granule (3-5mm in diameter), containing 65-75% zirconium, 20-30% vanadium, and 3-10% iron (preferably 70%, 25%, and 5%), with a specific surface area ≥50m². 2 / g. During activation, the getter is loaded into the purifier (316L stainless steel, 400mm diameter, 2500mm height), with a loading of 350kg, and vacuumed to <10. -3 Pa, heat at 350℃ for 30 minutes to remove the surface oxide layer.

[0044] During operation, the gas is at a speed of 200m 3 The purifier is fed at a pressure of 1.8 bar per hour, with a residence time of 10-15 seconds (preferably 12 seconds). The getter reacts chemically with oxygen and water to generate stable oxides and hydroxides. The outlet impurity concentration is monitored in real time; if it exceeds the limit, the getter is replaced, and reactivation is required after replacement to ensure stable removal efficiency.

[0045] S26: Hydrogen removal and recovery. The core module is equipped with a three-stage metal getter purifier at the end to remove hydrogen and recover hydrogen-rich gas. The first stage is a Zr-V-Fe getter purifier (300mm diameter, 2000mm height, 200kg packing, 350℃, 1.6bar), which initially removes hydrogen to ≤10ppm; the second stage is a Ti-Zr-V nanofilm getter purifier (same specifications, 250℃, 1.4bar), which deeply removes hydrogen to ≤1ppm. This getter is deposited on a porous metal substrate with a thickness of 1-5μm (preferably 3μm) using magnetron sputtering technology, and the adhesion is enhanced after annealing; the third stage is a Pd / Ag alloy membrane separator (tubular, 50mm inner diameter, 1000mm length, 10μm membrane thickness, 400℃, 1.2bar pressure difference), which selectively permeates hydrogen to obtain hydrogen-rich gas (≥90%), which is recovered and used as fuel, while the unpermeated gas enters the downstream module.

[0046] The post-implementation protection module is used to monitor impurity concentration in real time, adjust process parameters, remove metal particles, and ensure product quality. The specific implementation steps are as follows: S3: Post-startup preparations. Before startup, check the integrity of equipment such as the online monitoring system, PLC, and nanoporous filter components; calibrate the Fourier transform infrared spectrometer and GC-ICP-MS with standard samples to ensure detection accuracy (arsenic ≤0.001ppb, carbon dioxide, etc. ≤0.005ppm, metal ions ≤0.01ppb); set parameter thresholds in the PLC (arsenic 0.05ppb, adsorption tower breakthrough threshold, etc.), and the central control unit collects data every 10 seconds.

[0047] S31: Online impurity monitoring and processing. Four monitoring points are set at the S21, S23, S24, and S25 outlets, covering the core process. Fourier transform infrared spectrometer (model Nicolet iS50, wavelength 400-4000cm²) -1 The instrument performs real-time detection of phosphine, arsine, carbon dioxide, and water, with a cycle time of 10 seconds per test. A GC-ICP-MS (Agilent 7890A-7700x) is used to detect metallic impurities, with a cycle time of 30 seconds per test. Detection data is transmitted to the PLC and central control unit in real time, with automatic alarms triggered when values ​​exceed limits. The instrument is calibrated every 24 hours to ensure detection accuracy.

[0048] S32: Adaptive feedback regulation. The control system consists of a PLC (Siemens S7-400), a central control unit, sensors, and actuators. When the arsine at the S21 outlet exceeds 0.05 ppb, the PLC automatically adjusts the parameters: 0.05-0.1 ppb, laser frequency 150 Hz, single pulse energy 150 mJ, residence time 8 s; exceeding 0.1 ppb, frequency 200 Hz, energy 200 mJ, residence time 10 s, until the standard is met. When the impurities at the S23 and S24 outlets reach the breakthrough threshold, the system automatically switches to the standby adsorption tower, and the saturated tower undergoes online thermal regeneration (nitrogen purging, flow rate 50-200 mL / min, pressure 10-50 mbar, temperature 200-350℃, heat preservation 2-6 h), and then switches back to standby.

[0049] S33: Metal Particle Filtration and Product Collection. The gas treated in S25 is passed through a series of nanoporous filter components, sequentially filtered through a 0.1μm ceramic membrane and a 5Å carbon molecular sieve membrane to remove metal particles (≤0.1ppb), yielding high-purity phosphine product. Product testing confirms: purity 7N-8N grade, arsine <0.01ppb, carbon dioxide <0.1ppm, oxygen <0.01ppm, water <0.01ppm, total metal ion content <0.1ppb, phosphine yield ≥95%. Qualified product is stored in a dedicated high-pressure storage tank (316L stainless steel, pressure 3.0-5.0 bar) and transported to subsequent usage stages. The storage tank is regularly inspected to prevent leakage.

[0050] To verify the feasibility and stability of this process, large-scale continuous production validation was conducted: crude phosphine feedstock (93% phosphine, containing various impurities) was selected, and the process was operated according to the above steps for 720 hours of continuous production, with samples taken for testing every 24 hours. The results showed that the product purity remained stable at around 7.5N, all impurity indicators met the requirements, the phosphine yield remained stable at 95.5%-96.2%, the adsorbent and getter showed stable performance after regeneration, and the equipment operated without abnormalities. This demonstrates that this process can achieve stable large-scale production, solves the technical problems of existing processes, breaks the dependence on imports of high-end, high-purity phosphine, and promotes the localization of electronic specialty gases.

[0051] The same or similar labels correspond to the same or similar parts; The terms used to describe positional relationships in the accompanying drawings are for illustrative purposes only and should not be construed as limiting this patent. Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all implementation methods here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the claims of the present invention.

Claims

1. A distillation purification process for high-purity phosphine, characterized in that, The purification process includes, in sequence, a pre-treatment module, a core deep purification module, and a post-protection module. In the pretreatment module, the crude phosphine is subjected to cryogenic pre-dehydration, modified activated carbon adsorption desulfurization, and cryogenic removal of light components in sequence. In the core deep purification module, a 193nm ArF excimer laser is used to selectively photodissociate arsine in the gas phase stream, generating elemental arsenic particles, which are then captured by a metal oxide trap. Residual arsine is then selectively adsorbed using an amino-functionalized UiO-66-NH2 metal-organic framework material. Carbon dioxide is then selectively adsorbed using a Zn-MOF-74 metal-organic framework material. Finally, oxygen and water are deeply removed using a Zr-V-Fe non-evaporative metal getter. The post-support module includes an online impurity monitoring system and an adaptive feedback control system based on a programmable logic controller to achieve closed-loop adjustment of process parameters.

2. The purification process for high-purity phosphine according to claim 1, characterized in that, Includes the following steps: S1: Preprocessing; S11: Crude phosphine is introduced into a three-stage series spiral tube cryogenic cold trap, with the temperatures of each stage set to -60℃, -80℃ and -100℃, respectively, to remove water vapor and carbon dioxide. S12: The phosphine gas treated by S11 is passed into an adsorption tower filled with modified activated carbon to remove hydrogen sulfide and organic sulfur impurities at room temperature. S13: The phosphine gas treated by S12 is passed into a spiral tube heat exchanger at -160℃ to remove nitrogen, oxygen, argon and light methane impurities to obtain pretreated phosphine. S2: Core deep purification; S21: The pretreated phosphine prepared in S13 is introduced into the laser-induced dissociation reaction chamber at a controlled flow rate and irradiated with a 193nm ArF excimer laser with a laser pulse frequency of 50-200Hz and a single pulse energy of 50-200mJ to selectively photodissociate the arsenane into elemental arsenic particles. S22: The gas treated by S21 is passed into a metal oxide collector filled with a CuO / Al2O3 composite bed, and the elemental arsenic particles are oxidized and collected into As2O3 at 250℃. S23: The gas treated by S22 is passed into an adsorption tower filled with UiO-66-NH2 metal-organic framework material, and residual arsenic is selectively adsorbed at -40℃ and 1.5 bar. S24: The gas treated by S23 is passed into an adsorption tower filled with Zn-MOF-74 metal-organic framework material, and carbon dioxide is selectively adsorbed at 25℃ and 2.0 bar. S25: The gas treated by S24 is passed into a purifier filled with Zr-V-Fe non-evaporable getter, and oxygen and water are deeply removed at 350℃ activation and 350℃ operating temperature. S3: Rear protection; S31: Online impurity monitoring points are set at the outlets of the laser dissociation reaction chamber S21, S23, S24 and S25. The concentrations of phosphine, arsine, carbon dioxide and water are detected by Fourier transform infrared spectroscopy, and the concentrations of metal impurities are detected by gas chromatography-inductively coupled plasma mass spectrometry. S32: The real-time detection data of S31 is collected by the programmable logic controller and uploaded to the central control unit. When the arsine concentration exceeds 0.05 ppb, the programmable logic controller automatically adjusts the laser pulse frequency, single pulse energy and gas residence time. When the concentration of impurities at the outlet of the adsorption tower reaches the breakthrough threshold, the control system automatically switches to the standby adsorption tower and switches the saturated adsorption tower to online thermal regeneration mode. S33: The gas treated by S25 is passed into a series-connected nanoporous filter assembly, and filtered sequentially through a 0.1μm ceramic membrane and a carbon molecular sieve membrane with a pore size of 5Å to remove metal particles and obtain a high-purity phosphine product.

3. The purification process for high-purity phosphine according to claim 2, characterized in that, The three-stage series spiral tube cryogenic cold trap described in S11 has a tube diameter of 10mm, a pitch of 30mm, and a total length of 5m for a single stage tube pass; the flow rate of the crude phosphine and the gas-liquid ratio of the cold trap heat exchange area are controlled between 100:1 and 500:

1.

4. The purification process for high-purity phosphine according to claim 2, characterized in that, The operating space velocity of the modified activated carbon adsorption tower described in S12 is 200-500 h⁻¹. -1 The operating pressure is 1.0 bar; the modified activated carbon is obtained by impregnation with 5-10 wt% potassium hydroxide solution and then calcination at 400℃ under nitrogen atmosphere for 2-4 hours.

5. The purification process for high-purity phosphine according to claim 2, characterized in that, The preparation method of the UiO-66-NH2 metal-organic framework material described in S23 is as follows: Zirconium chloride and 2-aminoterephthalic acid are dissolved in N,N-dimethylformamide in a molar ratio of 1:1 to 1:2, acetic acid is added as a regulator, and the mixture is hydrothermally reacted at 120°C for 24 h. After centrifugation, the mixture is washed successively with N,N-dimethylformamide and methanol, and then vacuum dried at 80°C for 12 h to obtain the UiO-66-NH2 crystal material.

6. The purification process for high-purity phosphine according to claim 2, characterized in that, The preparation method of the Zn-MOF-74 metal-organic framework material described in S24 is as follows: Zinc nitrate hexahydrate and 2,5-dihydroxyterephthalic acid are dissolved in a mixed solvent of N,N-dimethylformamide, ethanol and water in a molar ratio of 2:1 to 4:

1. The mixture is then hydrothermally reacted at 120°C for 48 hours. After filtration, the mixture is washed with N,N-dimethylformamide and methanol, and then activated under vacuum at 150°C for 12 hours to obtain the Zn-MOF-74 material. After the Zn-MOF-74 material is saturated with adsorption, it is regenerated by purging with nitrogen gas at 120°C and a vacuum of 10-50 mbar. The material can be recycled ≥500 times.

7. The purification process for high-purity phosphine according to claim 2, characterized in that, The activation conditions for the Zr-V-Fe non-evaporable getter described in S25 are: 350℃ and a vacuum degree <10. -3 Heating at Pa for 30 minutes; the mass fraction of each metal in the getter is: zirconium 65-75%, vanadium 20-30%, iron 3-10%.

8. The purification process for high-purity phosphine according to claim 2, characterized in that, The operating conditions for the online thermal regeneration mode described in S32 are as follows: nitrogen is used as the purge gas, the purge flow rate is 50-200 mL / min, the system pressure is 10-50 mbar, the heating temperature is 200-350℃, and the holding time is 2-6 h.

9. The purification process for high-purity phosphine according to claim 2, characterized in that, The process also includes a three-stage metal getter purifier at the end of the core deep purification module. The first stage is a Zr-V-Fe non-evaporable getter, the second stage is a getter deposited on a porous metal substrate with a thickness of 1-5 μm using magnetron sputtering technology, with an operating temperature of 250℃, and the third stage is a Pd / Ag alloy membrane separator with a membrane thickness of 10 μm, an operating temperature of 400℃, and a pressure difference of 0.5-2.0 bar, used to remove hydrogen impurities and recover the hydrogen-rich gas from the permeation side for use as fuel.

10. The purification process for high-purity phosphine according to claim 1, characterized in that, The high-purity phosphine product produced by the process has a purity of 7N-8N, with arsine content <0.01ppb, carbon dioxide content <0.1ppm, oxygen content <0.01ppm, water content <0.01ppm, and total metal ion content <0.1ppb; the phosphine yield is ≥95%.

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