56 results about "Ultra high purity" patented technology

The invention discloses a preparation method of an ultra-pure hydroxylamine aqueous solution, and relates to the field of organic chemistry and chemical industry production. The method comprises the following steps: reacting electronic-grade hydroxylamine salt with organic alkali in a proper solvent to generate hydroxylamine, then separating and removing salt and unreacted hydroxylamine in a reaction solution through a mercaptopyridine ion exchange modified membrane, and finally concentrating the solution into 50wt% ultra-high-purity hydroxylamine aqueous solution by adopting reduced pressure evaporation or multi-effect evaporation. The process has the characteristics of high efficiency, environmental protection, simplicity and easiness in operation, effectively improves the purity, yield and separation efficiency of hydroxylamine, and meets the strict requirements of electronic grade hydroxylamine on purity and metal ion content.

The invention relates to the technical field of high-purity quartz purification methods, in particular to a high-purity quartz green low-consumption purification method which comprises the following steps: S1, plasma-assisted crushing pretreatment; s2, complex acid leaching-microwave synergistic impurity removal; s3, fluidized chloridizing roasting; s4, nano bubble water washing-targeted adsorption; s5, performing vacuum heat purification; according to the purification method of the high-purity quartz, the step of complex acid leaching-microwave synergistic impurity removal is adopted, highly toxic hydrofluoric acid in a traditional chemical acid leaching method is abandoned, and the toxicity of waste liquid is greatly reduced; compared with a traditional high-temperature chlorination method which needs a high temperature of 1300 DEG C or above, the method adopts fluidized chlorination roasting, so that the roasting temperature is reduced by 500 DEG C, and the energy consumption is reduced by 40%; nano-bubble ultrapure water is adopted for ultrasonic cleaning, the cleaning efficiency can be improved by 50%, and residual impurities are effectively removed; through innovative design and synergistic effect of all the steps, ultra-high purity of SiO2 with the purity being greater than or equal to 99.996% is realized, and meanwhile, environmental protection, energy conservation and consumption reduction as well as industrial stable production are taken into consideration.

The invention belongs to the technical field of electrolyte materials, and discloses a high-purity lithium bis (fluorosulfonyl) imide solution as well as a preparation method and application thereof. The preparation method of the high-purity lithium bis (fluorosulfonyl) imide solution comprises the following steps: 1) mixing inert chloralkane and lithium carbonate to form a suspension, dropwise adding bis (fluorosulfonyl) imide into the suspension at reaction temperature and pressure for reaction, after the reaction is finished, performing filter pressing, washing, and performing filter pressing again to obtain a filter cake; and 2) crushing the filter cake, feeding the crushed filter cake into a closed-loop circulating fluidized bed, sequentially drying in a low-temperature area and a medium-temperature area, instantaneously contacting and dissolving the obtained hot powder with an atomized and sprayed carbonate solvent to form a solution, and performing microfiltration to obtain the high-purity lithium bis (fluorosulfonyl) imide solution. The lithium bis (fluorosulfonyl) imide solution has ultra-high purity and ultra-low moisture, the content of other impurities such as chloride ions, free acids and metal ions is extremely low, additional steps of dehydration, purification or acidity adjustment and the like are not needed, and the lithium bis (fluorosulfonyl) imide solution can be directly used for preparing a high-performance lithium ion battery electrolyte.

The disclosed technology encompasses novel methods, systems, and materials for the efficient recycling and upgrading of carbon dioxide containing streams and their conversion into high purity methane and ultra-high purity methane. In various embodiments, the methods comprise utilizing a reactor equipped with both a sorbent and catalyst; supplementing the incoming stream with appropriate amounts of hydrogen to fully convert the carbon dioxide; initiating flow of the incoming stream in the sorbent-enhanced catalysis reactor; removing contaminants like nitrogen with sorption or reactors; drying the gas; and finally injecting the gas into the infrastructure of industrial process for the gas. Notably, the reaction of carbon dioxide with hydrogen gas to yield methane takes place at a temperature substantially consistent with the desorption stage on the catalytic unit. This invention represents a significant advancement in carbon upgrading processes, offering a highly efficient and reliable method for producing high purity methane and ultra-high purity methane.

This application discloses a method for preparing ultra-high purity citric acid monohydrate based on supercritical CO2, belonging to the field of citric acid preparation technology. The method includes the following steps: dissolving citric acid monohydrate in an organic solvent to prepare a citric acid solution; spraying the citric acid solution into a supercritical CO2 environment to crystallize the citric acid using the supercritical anti-solvent effect; performing dynamic washing with pure supercritical CO2; and obtaining ultra-high purity citric acid monohydrate crystals after depressurization and drying. The citric acid monohydrate product prepared by this method has high purity, high light transmittance, low total metal ion content, controllable crystal habit, and low organic solvent residue, meeting the stringent requirements of high-end applications such as electronic and pharmaceutical grades.

The present application provides a low odor / low whitening structure instant adhesive and a preparation method thereof. The low odor / low whitening structure instant adhesive comprises 70-90 wt% of cyano acrylate, 3-20 wt% of acrylic acid copolymer, 1-13 wt% of fumed silica, 0.2-2 wt% of plasticizer, 0.1-1 wt% of carbon black and 0-0.05 wt% of additive in terms of mass fraction. The present application selects ultra-high purity monomers in the environment of low polymerization inhibitor, which can significantly shorten the polymerization induction period, so that the monomer can be instantaneously initiated and completely cured after contacting the surface of the substrate, thereby minimizing the release of volatile monomers into the environment, further reducing the gaseous monomer that causes respiratory tract / mucosa irritation from the source, and inhibiting the polymerization of volatile monomers in the air to form white powder.

In semiconductor manufacture requiring ultra high purity water, particles of specified sizes are detected using acoustic particle detection capable of detecting nanoparticles. A sensor unit receives a flow of water, with the pressure and rate of flow to the sensor controlled closely. In each sensor unit is a measurement cell to receive a continuous flow of water, with a transducer module engaged with the cell to deliver an acoustic pulse at a known level of intensity as the liquid flows through the cells, the acoustic pulse acting on the liquid at a focus zone to cause cavitation in the event a particle of size detectable at that intensity is present. A waveform emitter / receiver connected to the sensor unit sends high-frequency, high-voltage signal to the transducer module to cause the acoustic pulse, and it also receives a waveform echo indicating a cavitation event. The system is controlled by a microprocessor.

The invention discloses an electrochemical synthesis method of an ultra-high-purity precious metal compound, which comprises the following steps: dissolving precious metal powder in a high-purity acid solution system by adopting an electrochemical dissolution process in a clean environment to form an ionic precious metal, selectively removing impurities through acid-resistant chelating resin, and carrying out reduced pressure distillation and concentration to obtain the ultra-high-purity precious metal compound. In the process, introduction of other impurity ions is avoided, the efficiency is high, and industrial batch production is easy. The purity of the obtained precious metal compound can reach 99.999% or above, and the obtained precious metal compound can be used as a raw material in the fields of chips, electrons, catalysts and the like.

The invention relates to the technical field of inorganic salt purification, and discloses high-purity ammonium sulfate and a preparation process thereof.The preparation process includes the following steps that firstly, a magnetic response macrocyclic ether complexing agent is added into an ammonium sulfate solution to be purified, the complexing agent can specifically capture impurities such as potassium ions, and a stable complex with magnetic responsiveness is formed; then, selectively crystallizing and separating out the target product ammonium sulfate under a mild condition by a gas-phase anti-solvent crystallization method, and meanwhile, effectively repelling a large-volume impurity complex into a mother solution. The key step is that obtained solid-liquid mixed crystal mush is introduced into a gradient magnetic field for enhanced separation. Through creative integration of molecular recognition, phase equilibrium engineering and a magnetochemical separation technology, the limitation of a co-crystallization effect is fundamentally broken through, and ultra-high-purity ammonium sulfate with extremely low impurity content can be prepared in an efficient and environment-friendly manner.

The invention relates to a metal oxide photoresist and a purification method thereof. The purification method comprises the following steps: S1, dissolving a metal oxide crude product containing metal ion impurities in a specific solvent to obtain a crude product solution; s2, applying crystallization driving force to the crude product solution to induce metal oxide crystals to separate out, so as to obtain metal oxide crystals; s3, separating the metal oxide crystal from the crude product solution to obtain a crystal wet cake; s4, washing and drying the crystal wet cake to obtain a high-purity crystal; and S5, dissolving the high-purity crystal in a photoresist solvent to obtain a purified metal oxide photoresist solution. According to the method, the metal ion impurity concentration of the metal oxide photoresist can be stably reduced, and the requirement of the EUV photoetching process on ultra-high purity is met. The purification process is simple and rapid, the purification time is greatly shortened, and the purification efficiency is improved.

The invention discloses a preparation method of a high-purity aluminum-based fine-grain cast ingot, and belongs to the technical field of target material preparation and non-ferrous metal material forming. The preparation method of the high-purity aluminum-based fine-grain cast ingot comprises the following steps: (1) raw material pretreatment and vacuum charging; (2) preheating and temperature control of a high-purity graphite mold; (3) carrying out vacuum induction melting and homogenization; (4) precise casting; (5) multidirectional composite vibration solidification in the mold; (6) in-mold heat preservation and rapid water quenching; a vertical-horizontal alternate combined vibration motor is used for achieving melt global vibration, a 99.999% high-purity graphite crucible and a mold are matched for blocking contact pollution, a refining agent is not needed, and coarse grains of several centimeters to dozens of centimeters in high-purity aluminum can be effectively refined to the average grain size of 0.90 centimeters (namely within 1 centimeter); while the ultra-high purity of 5N grade and above is ensured, the crystal grain uniformity is improved, the processing is simplified, the loss is reduced, and the method is suitable for high-end fields such as semiconductor target materials and precise components.

The invention relates to the technical field of carbon dioxide extraction and purification, in particular to a preparation process of ultra-pure carbon dioxide. A preparation process of ultra-pure carbon dioxide comprises the following steps: transferring a liquid phase III into an absorption tower filled with a carbon dioxide adsorption material which is a methyl functionalized covalent organic framework material coated with a polar polymer, so as to obtain a carbon dioxide-rich adsorption material; and transferring the carbon dioxide-rich adsorption material into a desorption tower to obtain the ultra-pure carbon dioxide. According to the preparation process of the ultra-high-purity carbon dioxide, a low-temperature rectification method is adopted, washing, flash evaporation and a carbon dioxide adsorption material are cooperatively matched, and impurity components such as SO2, H2, CO, CH4, N2 and 02 in crude carbon dioxide feed gas are removed, so that the ultra-high-purity carbon dioxide is obtained.

Processes for producing two CO2 streams having different purities, including one stream comprising ultra high purity CO2. The processes incorporate a second fractionation column in a CO2 fractionation process. The bottoms stream from the first cryogenic fractionation column is sent to the second CO2 fractionation column. The second CO2 fractionation column can produce ultra high purity CO2. The bottoms stream from the first column can be divided and a portion of the bottoms stream can be recovered as a second CO2 product stream having a lower purity than the purity of the product stream.

The invention discloses an efficient diethyl ether purification process, and belongs to the technical field of diethyl ether purification processes. Comprising the following steps: dynamically adsorbing diethyl ether through an adsorption column filled with a composite filler; adding a complexing agent into the effluent, stirring and reacting to obtain a mixed solution; performing normal-pressure separation on the mixed solution through a divided-wall rectifying tower, then performing reduced-pressure separation, collecting fractions, filtering the fractions through a polytetrafluoroethylene membrane, and packaging the fractions to obtain the high-purity diethyl ether. The composite filler is prepared from thiourea modified D101 macroporous resin and 4A molecular sieve powder through alumina sol treatment, silane coupling agent modification and programmed heating firing. The complexing agent is prepared by carrying out reaction on SAA-15 mesoporous molecular sieve loaded phosphotungstic acid and an 18-crown-6 ether derivative. According to the process, peroxide, trace moisture, alcohol and organic impurities in diethyl ether are remarkably removed, efficient separation and purification are achieved, an ultra-high-purity diethyl ether product is obtained, meanwhile, the process is stable and efficient, and the process is suitable for preparing high-purity diethyl ether.

The invention relates to the technical field of preparation of anhydrous indium chloride, in particular to a preparation method of anhydrous indium chloride, which comprises the following steps: (a) providing an indium source and a chlorine source, the indium source being indium metal or indium compound, and the chlorine source being chlorine, hydrogen chloride or organic chloride; and (b) in an anhydrous inert atmosphere, introducing the indium source and the chlorine source into a reactor, controlling the reaction temperature in a range of 100-400, and carrying out a chlorination reaction for 1-10 hours to generate the indium chloride intermediate. According to the preparation method of anhydrous indium chloride, a product with ultra-high purity and stable chlorine content can be stably obtained by effectively inhibiting a hydrolysis reaction, meanwhile, the hygroscopicity of the product is remarkably reduced, and the product is convenient to store and transport. The technological process is mild and controllable, the safety is high, toxic corrosive gas is prevented from being used, and the method has the remarkable advantages of being easy and convenient to operate and environmentally friendly.

Systems for detecting gas leaks in gas systems are provided. The systems can include: at least one gas cylinder; at least one valve assembly operatively engaged with the gas cylinder; and a purge conduit assembly operatively engaged with an interior portion of the valve assembly. Methods for detecting gas cylinder leaks in a gas system are provided. The methods can include providing purge gas through an interior portion of a valve assembly operably coupled to a gas cylinder. The system is enclosed within a cabinet; the method can include providing positive pressure within the cabinet sufficient to provide flow through the purge conduit assembly. Ultra-high purity gas cylinder valve assemblies are provided. The assemblies can include: a diaphragm separating an upper and lower portion of the valve assembly; a purge gas input conduit in fluid communication with the upper portion; and a purge gas outlet conduit in fluid communication with the upper portion.

The application discloses a preparation method of tetra (dimethylamine) hafnium and belongs to the technical field of group IVB metal organic compound preparation. The preparation method comprises the following steps: S1, once rectification of tetra (dimethylamine) hafnium crude product, and collection of the first main distillate; S2, dissolution of the first main distillate, and recrystallization to obtain crystals; S3, dissolution of the crystals for secondary rectification, and collection of the second main distillate. The tetra (dimethylamine) hafnium crude product is derived from waste liquid in a production process of cyclopentadienyl tris (dimethylamine) hafnium, and the crude product contains ≤8.0 ppm of Fe and ≤1.0 ppm of Ti; the application realizes 6N level (more than 99.9999%) ultra-high purity recovery of TDMAHf product in CpHf synthesis waste liquid by optimizing key parameters such as rectification and recrystallization parameters, the recovered product fully meets the strict requirements of high-end fields such as semiconductor thin film deposition on metal precursors, the preparation method has the advantages of short process cycle, high processing efficiency and no introduction of other impurities, and can realize industrial application.

The present invention relates to an ultra-high purity and ultra-high crystallinity polypropylene for a secondary battery separation membrane and a method for manufacturing the same, the ultra-high purity and ultra-high crystallinity polypropylene being characterized by having a residual inorganic content of 30 ppm or less and an isotactic quintuple fraction of 98% or more. According to the present invention, in order to improve the performance of the secondary battery separation membrane, inorganic substances, low-molecular substances and low-crystalline substances in polypropylene are reduced by adjusting the addition ratio of the main catalyst, the accelerator and the cocatalyst in the polymerization process, the ash removal process for removing residual inorganic substances, and the removal of low-molecular substances and atactic polypropylene; therefore, the polypropylene can simultaneously show ultra-high purity and ultra-high crystallization characteristics.

The invention discloses a chlor-alkali brine deep purification device and method based on cooperation of membrane separation and ion exchange, and belongs to the technical field of chlor-alkali industrial brine refining. The device comprises an ultrafiltration / microfiltration membrane assembly, a chelating resin exchange column, an anion exchange membrane device and a neutralization tank which are sequentially communicated along a technological process. Through a three-stage synergistic process of membrane filtration pretreatment, deep removal of cations by double-layer resin and selective removal of anions by an electrically driven membrane, all-directional deep purification of suspended solids, colloids, multivalent cations, sulfate radicals and other impurities in the saline water is realized. The concentrated water backflow system is innovatively designed, the utilization rate of water resources is remarkably increased, generated waste liquid is automatically neutralized, and clean production is achieved. The device has the advantages of being high in integration level, good in purification effect, low in operation cost and the like, ultra-high-purity saline water can be provided for the electrolysis process, and the chlor-alkali product quality and economic benefits are remarkably improved.

The present disclosure relates to a process for the preparation of ultra high purity alkali metal hexafluorophosphate (MPF6) comprising the steps of (a) charging alkali metal fluoride (MF) into a first reactor 'B' and flushing the first reactor 'B' with nitrogen, (b) cooling the first reactor 'B' to a predetermined temperature, the method comprises the following steps: (a) dissolving an alkali metal fluoride (MF) into a first reactor 'A', then charging anhydrous hydrogen fluoride (AHF) gas into a first reactor 'B' and stirring the mixture comprising the alkali metal fluoride (MF) dissolved in the AHF, (c) cooling the mixture comprising the alkali metal fluoride (MF) dissolved in the AHF in the first reactor 'B' to a predetermined temperature, (d) charging phosphorus pentachloride (PCl5) into a second reactor 'A' and adding the AHF in batches, the invention relates to a method for producing phosphorus pentafluoride (PF5) and hydrogen chloride (HCl) gas, (e) reacting alkali metal fluoride (MF) dissolved in AHF in a first reactor 'B' with a mixture of phosphorus pentafluoride (PF5) and hydrogen chloride (HCl) gas obtained in step (d) to obtain an alkali metal hexafluorophosphate mother liquor dissolved in AHF under the coverage of PF5 gas, (f) cooling the first reactor 'B' to a predetermined temperature, and (f) separating the alkali metal hexafluorophosphate mother liquor from the first reactor 'B' to obtain the phosphorus pentafluoride (PF5) and hydrogen chloride (HCl) gas. The present invention relates to a method for preparing an alkali metal hexafluorophosphate (MPF6), characterized in that the alkali metal hexafluorophosphate (MPF6), selected from NaPF6 or KPF6 or CsPF6, is dissolved in AHF, and the alkali metal hexafluorophosphate mother liquor dissolved in AHF is maintained at said temperature for a predetermined time, followed by filtration and drying at a predetermined temperature, to obtain the alkali metal hexafluorophosphate (MPF6) selected from the group consisting of NaPF6 or KPF6 or CsPF6.

The invention discloses a method and a system for preparing high-purity lithium sulfide based on a mechanochemistry principle, and belongs to the field of inorganic chemistry and battery materials. According to the method, mechanical force is applied to lithium hydride, a sulfur source and a lithium source compound, and self-propagating exothermic reaction is triggered and maintained to generate lithium sulfide; the system comprises a reaction cavity, a mechanical force generation mechanism, a control module and an integrated gas treatment device. The core of the method is that through systematic integration and cooperation of three technical dimensions of mechanical force triggering, closed-loop control and in-situ purification, fundamental reconstruction from an energy utilization mode to a product purification path is realized. Compared with the prior art, the method has the advantages that the production energy consumption and the purification cost are expected to be greatly reduced, the raw material adaptability is wide, and a subversive technical path is provided for low-cost and large-scale production of the ultra-high-purity lithium sulfide.

The invention provides a low-odor / low-whitening structure instant adhesive and a preparation method thereof. The low-odor / low-whitening structure instant adhesive is prepared from the following components in percentage by mass: 70 to 90 weight percent of cyanoacrylate, 3 to 20 weight percent of acrylic acid copolymer, 1 to 13 weight percent of fumed silica, 0.2 to 2 weight percent of plasticizer, 0.1 to 1 weight percent of carbon black and 0 to 0.05 weight percent of additive. The polymerization induction period can be remarkably shortened by selecting the ultra-high-purity monomers in the environment of a low polymerization inhibitor, so that the monomers can be instantaneously initiated and completely cured after being in contact with the surface of a base material, release of volatile monomers to the environment is reduced to the maximum extent, and then gaseous monomers causing respiratory tract / mucosa stimulation are reduced from the source; and the volatile monomer is inhibited from polymerizing in the air to form white powder.

The invention discloses a separation and purification method for a mixed solution of 2-methyltetrahydrofuran-2-methylfuran, tetrahydrofuran, water and the like, and relates to a separation process combining liquid-liquid separation and multi-step rectification. The method comprises the following steps: firstly, carrying out liquid-liquid separation on a mixed solution containing 2-methyltetrahydrofuran, 2-methylfuran, tetrahydrofuran, water and alcohol impurities to obtain a water phase and an organic phase; sequentially carrying out high-pressure rectification and reduced-pressure rectification on the organic phase to obtain a 2-methyltetrahydrofuran concentrated solution with the purity being greater than or equal to 99.99%; and finally, further purifying through product rectification operation to prepare an ultra-high-purity 2-methyltetrahydrofuran product. According to the method, the target product recovery rate is greater than or equal to 92.5%, and the method has the advantages of high purity, low energy consumption, excellent yield, strong process stability and the like, and is suitable for the fields of green chemical industry, medicine synthesis, fine chemicals and the like with high requirements on solvent quality.

The invention relates to a preparation method of electronic grade hypoxanthine, which comprises the following steps: taking a hypoxanthine crude product synthesized by an enzymic method as a raw material, mixing the hypoxanthine crude product with high-purity water at the temperature of 30-60 DEG C, adjusting the pH value to 7-9, adding 0.1%-2% of neutral or alkaline protease to hydrolyze protein to react for 0.5-3 hours, cooling to 5-30 DEG C, and performing suction filtration to obtain the electronic grade hypoxanthine. Dissolving the wet product with an alkaline aqueous solution at 50-80 DEG C, removing impurities with activated carbon, performing hot filtration, adjusting the pH value of the filtrate to 6.5-7.5 with electronic-grade acid, cooling to 5-30 DEG C, crystallizing, performing suction filtration, washing the wet product with purified water for 3-5 times, and drying to obtain the product. Organic impurities, metal ions and environmental particles are systematically removed, and finally the ultra-high-purity electronic-grade hypoxanthine is prepared. The chemical purity of the prepared product is larger than or equal to 99.99%, the total metal ion content is smaller than or equal to 100 ppb, the moisture content is smaller than or equal to 0.1%, and the product has the advantages of being concentrated in particle size distribution and uniform in crystal form and completely meets the harsh requirements of OLED and other high-end photoelectric devices for key organic materials.

A deep purification method for removing trace silicon impurities in high-purity boric acid belongs to the technical field of inorganic chemical purification. The method sequentially performs pre-oxidation, complex shielding and selective precipitation on the crude boric acid solution for the transformation and preliminary separation of different forms of silicon impurities; then uses a composite adsorbent of layered double hydroxide and amino-functionalized mesoporous silica for deep adsorption; and finally obtains a high-purity boric acid solution through precise filtration separation including microfiltration, ultrafiltration and nanofiltration. Through the synergistic effect of multiple steps, the method can systematically solve the removal problem of colloidal silicon and dissolved silicon, stably reduce the silicon impurity content in boric acid to the ppb level, meet the ultra-high purity requirements of raw materials in the field of semiconductors and the like, and has the advantages of regenerable adsorbent and environmental friendliness.

This invention belongs to the field of wet electrolytic refining technology for recycled lead, and provides a method for electrolytically preparing ultra-high purity lead. It involves constructing a 1-hydroxyethylidene-1,1-diphosphonic acid-modified lead carbonate seed layer on the cathode plate surface, combined with a bypass impurity removal unit to continuously remove impurity ions from the electrolyte, and then using staged current density electrolysis to ensure uniform nucleation and stable deposition of lead on the cathode surface. The resulting cathode lead has a purity of not less than 99.996 wt%, and the deposited layer is dense, flat, and has a low risk of inclusions. This method solves the problems of difficulty in balancing high-throughput deposition and ultra-high purity, as well as the difficulty in synchronizing seed layer adhesion stability and pollution control in existing processes. It is suitable for the high-value preparation of recycled lead from waste lead-acid batteries.

The application relates to the technical field of nanomaterials, in particular to a process for preparing ultra-high-purity hydroxyl-free silicon dioxide, which comprises the following steps: S1, mixing a silicon source, an alkali and an organic modifier, then adding the mixture into a reaction medium to form a reaction solution, and performing microencapsulation treatment on the reaction solution to obtain reaction solution microcapsules; S2, adding the reaction solution microcapsules in a reaction process for synthesizing a composite frame material with a hollow structure, and performing high-temperature and high-pressure reaction to obtain a precursor material; S3, depositing magnetic ferroferric oxide nanoparticles on the surface of the precursor material through a hydrothermal method to obtain pretreated precursor material; and S4, performing high-temperature treatment on the pretreated precursor material at 800-850 DEG C under the action of argon oscillation, then performing magnetic selection and screening, and thus high-purity hydroxyl-free silicon dioxide can be obtained. The synthesized silicon dioxide has small particle size, a round and regular structure and good dispersity, and can be applied to the fields of electronic packaging materials, mechanical lubrication, ceramics and the like.

The application discloses a preparation method of ultrahigh-purity hydroxylamine aqueous solution and relates to the field of organic chemistry and chemical production. The method comprises the following steps: reacting electronic-grade hydroxylamine salt and an organic base in a proper solvent to generate hydroxylamine, then removing salt and unreacted hydroxylamine in the reaction solution through a sulfhydryl pyridine ion exchange modified membrane, and finally concentrating the solution to 50wt% ultrahigh-purity hydroxylamine aqueous solution through vacuum evaporation or multi-effect evaporation. The process has the characteristics of high efficiency, environmental protection and simple operation, effectively improves the purity, yield and separation efficiency of hydroxylamine, and meets the strict requirements of electronic-grade hydroxylamine on purity and metal ion content.

The disclosed technology encompasses novel methods, systems, and materials for the efficient recycling and upgrading of carbon dioxide containing streams and their conversion into high purity methane and ultra-high purity methane. In various embodiments, the methods comprise utilizing a reactor equipped with both a sorbent and catalyst; supplementing the incoming stream with appropriate amounts of hydrogen to fully convert the carbon dioxide; initiating flow of the incoming stream in the sorbent-enhanced catalysis reactor; removing contaminants like nitrogen with sorption or reactors; drying the gas; and injecting the gas into the infrastructure of industrial process for the gas. Notably, the reaction of carbon dioxide with hydrogen gas to yield methane takes place at a temperature substantially consistent with the desorption stage on the catalytic unit. This invention represents a significant advancement in carbon upgrading processes, offering a highly efficient and reliable method for producing high purity methane and ultra-high purity methane.