40 results about "Nitrogen molecule" patented technology

The invention provides an epitaxial growth process for improving doping uniformity of n-type doped silicon carbide, and relates to the technical field of semiconductors. The method is based on a chemical vapor deposition growth technology; 11 to 20 gt; the silicon carbide epitaxial growth is carried out by taking silicon carbide with a 4-degree silicon surface in the direction as a substrate, taking trichlorosilane (TCS) and ethylene (C2H4) as growth sources and taking ammonia gas (NH3) as a doping source. Ammonia gas is adopted as an n-type dopant, the decomposition efficiency of the n-type dopant is close to 100% at the temperature of 700 DEG C or above, and the energy of N-H bond breakage of ammonia gas molecules is 390 KJ / mo which is far lower than 946 KJ / mo needed by N-N bond breakage of nitrogen molecules. Therefore, compared with a traditional doping source such as nitrogen, the ammonia gas has higher doping efficiency, residues of excessive nitrogen-containing precursors in the reaction chamber can be reduced, the memory effect is reduced, and thus more excellent in-chip uniformity and stable inter-chip repeatability of the epitaxial wafer are obtained. The selection range of the doping source is widened, the accurate control of the doping concentration is realized, and the stability of the doping concentration in the continuous growth process is improved.

An ammonia production method involves producing ammonia from nitrogen molecules, in a production device for performing electrolysis, in the presence of a metal complex and a solid catalyst in a cathode, by providing electrons from a power source, protons from a proton source, and nitrogen molecules from a means for supplying nitrogen gas, and by providing hydrogen molecules by sending hydrogen molecules to an anode including sending hydrogen gas produced at the cathode to the anode. Concerning a metal complex and a solid catalyst, as the metal complex, rac-ethylenebis(4,5,6,7-tetrahydro-1-indenyl) zirconium dichloride or the like is used, and as the solid catalyst, a metal catalyst or the like is used.

The invention discloses a preparation method and application of a molybdenum monatomic photocatalyst for producing ammonia through nitrogen reduction, and belongs to the technical field of photocatalytic material preparation. According to the preparation method, molybdenum hexacarbonyl is taken as a metal precursor, and molybdenum single atoms are introduced into a covalent organic framework material sp2c-COF by adopting a solvothermal synthesis method, so that the covalent organic framework photocatalyst is obtained; according to the covalent organic framework photocatalyst, molybdenum single atoms are anchored, the local coordination environment of a covalent organic framework is finely controlled, the unique electronic structure and catalytic activity of the molybdenum single atoms can effectively optimize electron cloud distribution of COFs, the adsorption and activation capacity on nitrogen molecules is enhanced, and the covalent organic framework photocatalyst has the advantages that the covalent organic framework photocatalyst is high in catalytic activity and high in catalytic activity; the covalent organic framework photocatalyst can effectively inhibit the compounding of photo-induced electron-hole pairs so as to prolong the service life of photo-induced electrons, so that the covalent organic framework photocatalyst has excellent ammonia production performance, and the ammonia production activity can reach 372.6 [mu] mol.g <-1 >. H <-1 > under the conditions of visible light and pure water.

The invention relates to the technical field of catalyst preparation, and provides a nitrogen-containing molecule modified MXene loaded Pt monatomic catalyst, a preparation method and application, the preparation method comprises the following steps: S1, preparing an NH2 / CC electrode; s2, dipping the NH2 / CC electrode in a mixed solution of an MXene suspension and chloroplatinic acid hexahydrate at room temperature for reaction, and then irradiating and drying with a mercury lamp to obtain an NH2-MX / Pt-CC electrode; and S3, carrying out secondary amino modification to obtain the catalyst containing nitrogen molecule modified MXene to load Pt single atoms. According to the preparation method of the catalyst with the nitrogen-containing molecule modified MXene loaded with the Pt single atoms, the atom utilization rate of the material is effectively increased, reaction active sites are increased, meanwhile, the interaction between the two-dimensional material and the Pt atoms is enhanced, and the stability of the catalyst under the industrial and current density is improved.

The integrated adsorption tower of the oxygen generator comprises an adsorption tower main body, a gas inlet integrated cover part and a gas outlet integrated cover part which are arranged at the two ends of the adsorption tower main body, and a reversing valve arranged on the gas inlet integrated cover part, two molecular sieve cylinders and two air storage tanks are arranged in the adsorption tower main body, the nitrogen removal and noise reduction cylinder is positioned in the middles of the two molecular sieve cylinders and the two air storage tanks, the molecular sieve cylinders are communicated with the air storage tanks, the molecular sieve cylinders can be communicated with the nitrogen removal and noise reduction cylinder under the control of a reversing valve, the reversing valve controls air to alternately enter and remove nitrogen, the molecular sieve cylinders are filled with adsorbents, and the adsorbents are communicated with the nitrogen removal and noise reduction cylinder. The two molecular sieve barrels are integrated on one adsorption tower, so that the assembly difficulty is reduced, the production efficiency is improved, the space utilization rate is improved, and the nitrogen discharge noise is reduced by arranging the silencing barrel.

[Problem] To provide a nitrogen fixation method and a nitrogen fixation device which are capable of significantly reducing energy and cost and are easy to put into practical use. [Solution] According to the present invention, water 14, which is brought into contact with air and has dissolved the air, is brought into contact with a photocatalyst (photocatalyst layer 5), and the photocatalyst is irradiated with ultraviolet rays (light source 91), and thus ammonia, nitric acid, or nitrous acid is generated in the water 14 from nitrogen molecules in the air dissolved in the water 14 by a photocatalytic reaction.

An air purification system includes a linear electrode that generates electromagnetic resonance; an electric field probe that measures the electric field intensity; and a controller that controls power supplied to the linear electrode. The controller adjusts the frequency of the power supplied to the linear electrode and the position at which the power is supplied to the linear electrode, to maximize an output value of a signal indicating the electric field intensity. Feedback control is performed to make the amount of ozone always constant, by monitoring the amount of ozone generated and adjusting the amplitude modulation of the power supplied, so that ozone necessary for decomposing viruses is generated but harmful nitrogen oxides are not generated as a result of applying, to gas molecules contained in influent gas, an energy that is at least the dissociation energy of oxygen molecules and no greater than the dissociation energy of nitrogen molecules.

The integrated adsorption tower of the oxygenerator comprises an adsorption tower main body, a gas inlet integrated cover part and a gas outlet integrated cover part which are arranged at two ends of the adsorption tower main body, and a reversing valve arranged on the gas inlet integrated cover part, two molecular sieve cylinders and two air storage tanks are arranged in the adsorption tower main body, the nitrogen removal and noise reduction cylinder is positioned in the middles of the two molecular sieve cylinders and the two air storage tanks, the molecular sieve cylinders are communicated with the air storage tanks, the molecular sieve cylinders can be communicated with the nitrogen removal and noise reduction cylinder under the control of a reversing valve, the reversing valve controls air to alternately enter and remove nitrogen, the molecular sieve cylinders are filled with adsorbents, and the adsorbents are communicated with the nitrogen removal and noise reduction cylinder. The two molecular sieve barrels are integrated on one adsorption tower, so that the assembly difficulty is reduced, the production efficiency is improved, the space utilization rate is improved, and the nitrogen discharge noise is reduced by arranging the silencing barrel.

The invention relates to a granary nitrogen specificity monitoring system and method based on Li-LSX zeolite functionalized optical fiber, and the system comprises a transmitting unit which is used for transmitting an optical signal; the sensing unit is connected with the transmitting unit and is used for measuring a first resonance valley wavelength drift distance of an optical signal along with the change of the nitrogen concentration and the change of the environment temperature and pressure by utilizing the change of the refractive index after the lithium exchange low-silicon X-type zeolite selectively adsorbs nitrogen molecules; the reference unit is connected with the transmitting unit, is arranged in parallel with the sensing unit, and is used for measuring a second resonance valley wavelength drift distance of the optical signal along with the change of the environment temperature and pressure; and the receiving, demodulating and resolving unit is connected with the sensing unit and the reference unit, and is used for calculating the resonance valley wavelength drift amount caused by the nitrogen concentration according to the first resonance valley wavelength drift amount and the second resonance valley wavelength drift amount, and calculating the nitrogen concentration by using a preset model. The monitoring system has the advantages of high measurement precision, high response speed, stable performance and high reliability.

An air cleaning system (1) has a linear electrode (20) that generates electromagnetic resonance, an electric field probe (40) that measures the intensity of an electric field, and a control unit (70) that controls the power supplied to the linear electrode (20). The control unit (70) operates the frequency of the power supplied to the linear electrode (20) and the position at which the power is supplied to the linear electrode (20) to control the output value of a signal representing the intensity of the electric field to be maximum. The amount of generated ozone is monitored, and the control unit (70) operates in a manner to modulate the amplitude of the supplied power to perform feedback control so that the amount of ozone is always fixed, so that ozone that gives energy above the dissociation energy of oxygen molecules and below the dissociation energy of nitrogen molecules to gas molecules contained in the gas flowing in to decompose viruses is generated but harmful nitrogen oxides are not generated.

The invention discloses a carbon molecular sieve and a process for preparing high-purity oxygen by using the carbon molecular sieve, the surface of the carbon molecular sieve is provided with three types of micropores, the diameter of the first type of micropores is greater than the diameter of nitrogen molecules, and the diameter of the second type of micropores is between the diameter of oxygen molecules and the diameter of nitrogen molecules. The diameter of the third kind of micropores is smaller than that of oxygen molecules, the proportion of the first kind of micropores in the total amount of the micropores is smaller than 5%, and the proportion of the second kind of micropores in the total amount of the micropores is larger than 60%; according to the process for preparing high-purity oxygen by using the carbon molecular sieve, oxygen in air is adsorbed in a high-pressure environment, and then decompression and desorption are performed to obtain the high-purity oxygen. The method has the advantage that high-purity oxygen can be obtained at low cost.

The present invention relates to a method for measuring the coefficient of restitution of nano-sphere particle collision based on molecular dynamics, comprising: establishing two nano-sphere Al2O3 particle models using OVITO software; placing a nitrogen molecule model, an oxygen molecule model, and the two particle models in a simulation box to form a simulation object system, and importing the LAMMPS software; using comb3 and lj / cut mixed potential; setting simulation parameters, performing molecular dynamics simulation, obtaining parameter data during the movement of the particle model, and observing the deformation of the particle model during the collision process; post-processing the parameter data to obtain a force-displacement curve of the particle model, judging the collision occurrence and end time of the particle model, and determining the collision velocity of the particle model and the separation velocity during rebound, and calculating the collision coefficient of restitution of the particle model based on the velocity changes before and after the collision. The present invention overcomes the limitations of traditional methods and improves measurement accuracy.

The present disclosure provides a method of processing a liquid containing ammonia nitrogen from a first semiconductor fabrication machine. The method includes: adsorbing a plurality of ammonium (NH4+) ions in the liquid; desorbing the plurality of NH4+ ions to a solution; converting a fraction of the plurality of NH4+ ions into a plurality of ammonia (NH3) molecules; and electrolyzing the plurality of NH3 molecules to become a plurality of hydrogen (H2) molecules and a plurality of nitrogen (N2) molecules.

The invention relates to the technical field of molecular sieve oxygen production, and discloses a high-purity oxygen production adsorption tower which comprises a tower body, partition plates distributed in the vertical direction are fixed in the tower body, an air inlet cavity and a plurality of oxygen production cavities are defined by the partition plates and the tower body, and horizontal oxygen production inlet pipes are fixed in the oxygen production cavities; the oxygen generation net rack is arranged outside the oxygen generation inlet pipe in a sleeving manner; the rotating assembly is used for driving each oxygen generation net rack to rotate; a communication assembly and a nitrogen extraction assembly. According to the high-purity oxygen production adsorption tower, all the oxygen production cavities are sequentially communicated through the communicating assemblies, so that compressed air is discharged through the oxygen production inlet pipe and then makes contact with the oxygen production molecular sieve in the storage cavity, the nitrogen content in the compressed air is continuously reduced, and finally the concentration of oxygen discharged from the air outlet is increased; each oxygen generation net rack is driven by the rotating assembly to rotate, so that the oxygen generation molecular sieves at all positions can fully absorb nitrogen in compressed air discharged from the oxygen generation inlet, the consistent adsorption quantity of the nitrogen generation molecular sieves at all positions is ensured, and the concentration of discharged oxygen is further improved on the basis of reducing the difference.

The application provides a preparation method and application of high-nucleus cobalt cluster-based MOFs and derivatives thereof, including Co 16 -MOF-BDC-X, Co 16 -MOF-BPDC, crystallized in a tetragonal system, and a space group is P42 / nmc, wherein Co 16 The cell parameter of the MOF-BDC-X is: alpha=beta=gamma=90°, Co 16 The cell parameter of the MOF-BPDC is: alpha=beta=gamma=90°, the application adopts a strategy of assisted synthesis of double small molecules (azide molecules and formic acid molecules), and successfully constructs a series of novel high-nucleus cobalt cluster-based MOFs, including Co 16 -MOF-BDC, Co 16 -MOF-BDC-X (X=NH2, NO2, OH, Br) and Co 16 -MOF-BPDC, the application realizes a great improvement of solar energy conversion efficiency by regulating functional groups on the MOF ligand and modifying strong absorption photosensitive centers on the MOF metal node, and exhibits application in the field of photocatalysis.

This invention relates to the field of automatic control for ozone generation, specifically disclosing an optimized ozone generation control method and system based on improved fuzzy control. The method includes: acquiring the optical emission spectrum of the discharge chamber, extracting the rotational spectrum of nitrogen molecules, decoupling and calculating the instantaneous temperature of the micro-discharge channel, and outputting a thermodynamic mismatch coefficient through a first fuzzy inference; introducing the coefficient into the pulse power supply and the gas flow field loop respectively, and collaboratively adjusting the rise time, pulse width, repetition frequency, and turbulent airflow velocity of the nanosecond pulse; inputting the coefficient and oxygen atom spectral lines into a second fuzzy inference, adjusting the domain and threshold of the main fuzzy controller, and the main controller forming a three-dimensional input vector to output the pulse amplitude adjustment; inputting historical control data into a third fuzzy mining time-series correlation mode to generate a rule confidence correction factor to feed back and optimize the fuzzy rule base. This invention achieves micro-discharge channel thermal state sensing, multi-timescale collaborative control, and strategy self-evolution, significantly improving ozone generation efficiency and electrode lifetime.

The purpose of the present invention is to develop a method for the fermentative production of L-glutamic acid based on nitrogen molecules in the atmosphere using nitrogen-immobilized bacteria. The present invention develops a culture method for maintaining a state in which nitrogen-immobilizing ability is increased in nitrogen-immobilizing bacteria. This culture method is characterized by mixing an organic acid such as citric acid into a nitrogen-restricted medium placed in an open container. A method for producing L-glutamic acid by fermentation depending on nitrogen immobilization can be developed by culturing a gene-altered strain that highly expresses a citrate synthase gene and a citrate transporter gene using this culture method. In this process, a method for producing L-glutamic acid by fermentation that depends on nitrogen immobilization by using a modified strain that highly expresses a citrate synthase gene or a 2-methylcitrate synthase gene can be developed. The present invention relates to a method for producing the microorganism and a method for culturing the microorganism.

The present invention relates to the technical field of molecular sieve oxygen production, and discloses a high-purity oxygen production adsorption tower, including: a tower body, in which a partition plate distributed in the vertical direction is fixed, and the partition plate and the tower body enclose an air inlet cavity and a plurality of oxygen production cavities, and a horizontal oxygen production inlet pipe is fixed in the oxygen production cavity; an oxygen production wire mesh frame, sleeved outside the oxygen production inlet pipe; a rotating assembly, driving each oxygen production wire mesh frame to rotate; a communication assembly and a nitrogen extraction assembly. The high-purity oxygen production adsorption tower of the present invention sequentially conducts each oxygen production cavity through the communication assembly, so that after the compressed air is discharged through the oxygen production inlet pipe, it contacts the oxygen production molecular sieve in the storage cavity, continuously reduces the nitrogen content in the compressed air, and finally increases the oxygen concentration discharged from the air outlet. The rotating assembly drives each oxygen production wire mesh frame to rotate, so that the oxygen production molecular sieve everywhere can fully absorb the nitrogen in the compressed air discharged from the oxygen production inlet, ensuring that the adsorption amount of the nitrogen production molecular sieve everywhere is consistent, and further increasing the discharged oxygen concentration on the basis of reducing the difference.

The invention belongs to the technical field of oxygen generation systems, and particularly relates to a system and a method for purifying oxygen in a molecular sieve oxygen generation process. The system comprises a carbon dioxide filter, a moisture filter, an air temporary storage tank, an air compressor, an oil vapor filter, a plurality of adsorption towers, an oxygen storage tank, a nitrogen storage tank and a heat recovery device which are sequentially connected through pipelines and valves, each adsorption tower is filled with the modified molecular sieve material. The MOR molecular sieve structure is modified, so that the anti-aging and anti-pulverization performance of the modified molecular sieve material is improved, the modified MOR molecular sieve structure has the optimal pore structure and adsorption performance, the pore diameter and pore distribution uniformity are improved, a stable state can be kept for a long time, and the adsorption efficiency on nitrogen molecules is improved; the adsorption performance and the adsorption effect are improved, the adsorbent can be recycled, and the service life is prolonged. The heat effect influence and the pressure drop influence are reduced, and the stability and the adsorption efficiency of the system are improved.

The invention discloses a method for synthesizing ammonia, which is characterized in that nitrogen and hydrogen are used as reaction gases, and ammonia is synthesized under the normal pressure or low pressure condition under the action of a gaseous molecular accelerator and a catalyst, wherein the gaseous molecule accelerant is nitrogen oxide. Nitrogen oxide can react with hydrogen to generate ammonia, and active oxygen atoms generated by the reaction can activate nitrogen molecules, so that the ammonia synthesis reaction of nitrogen and hydrogen is greatly promoted, and efficient ammonia synthesis of nitrogen and hydrogen under normal pressure is realized. The synthesis ammonia reaction under the molecular accelerator can also be carried out at low pressure, and the synthesis ammonia rate and conversion rate can be improved by properly increasing the reaction pressure. Besides, a reaction system is optimized, such as reaction process parameters of a catalyst, air speed, composition, pressure, temperature and the like, so that the rate and the conversion rate of ammonia synthesis are also favorably improved, and the rate and the conversion rate of ammonia synthesis close to or exceeding those of traditional industrial Have-Bosch high-temperature and high-pressure ammonia synthesis are realized.

The present invention relates to the field of optical technology, and discloses a vortex beam generation system. The system comprises: a femtosecond laser light source, for generating a laser beam, wherein after the laser beam is split into two, one beam is used as a pump beam and the other beam is used as a probe beam; a pump light shaping module, for shaping the pump beam into a vector beam; a probe light shaping module, for shaping the probe beam into a circularly polarized beam; and a vortex light generation module, for focusing the vector beam and the circularly polarized beam together into a nitrogen-filled gas chamber, inducing a non-adiabatic arrangement of nitrogen molecules in the gas chamber by the vector beam, so that the nitrogen molecules are arranged according to the polarization direction of the vector beam during the recovery period, forming multiple molecular wave plates. After the circularly polarized beam passes through the multiple molecular wave plates, it is modulated into a vortex beam having a hand-direction opposite to that of the circularly polarized beam, thereby improving the quality of the generated vortex beam.

The invention discloses a preparation method of an organic framework material based on a boron-nitrogen dynamic covalent bond, which comprises the following steps of: obtaining a functional group modified boron-containing molecule 4, 7-bis (benzo [d] [1, 3, 2] boron dioxide heterocycle-2-yl) benzo [c] [1, 2, 5] thiadiazole and a nitrogen-containing molecule tris (4-(4-pyridyl) phenyl) amine through a series of organic synthesis means, and synthesizing the functional group modified boron-containing molecule 4, 7-bis (benzo [d] [1, 3, 2] boron dioxide heterocycle-2-yl) benzo [c] [1, 2, 5] thiadiazole. The organic framework material constructed by dynamic covalent bonds has excellent photocatalytic H2O2 generation capability. The invention provides a new scheme for adjusting the exciton-related properties of the organic polymer so as to improve the photocatalytic performance, and has potential application prospects in solar energy conversion and photocatalysis.

This makes it possible to predict the behavior of oxygen molecules within the pores of a carbon support. [Solution] The analysis method comprises a modeling step, a setting step, a simulation step, and a calculation step. In the modeling step, the carbon support of the hydrogen fuel cell is modeled as a cylindrical carbon nanotube model. In the setting step, the number of water molecule models, oxygen molecule models, and nitrogen molecule models to be placed within the carbon nanotube model is set. In the simulation step, a simulation is performed on the diffusion of water molecule models, oxygen molecule models, and nitrogen molecule models within the carbon nanotube model. In the calculation step, the diffusion coefficient of the oxygen molecule model is calculated based on the simulation results.

The present invention discloses a magnetic membrane separation device, an oxygen-enriched gas supply system and an oxygen-enriched combustion method. The magnetic membrane separation device of the present invention increases a magnetic field outside the membrane separation device, and cooperates with the poly-magnetic medium filled in the membrane material. By utilizing the different paramagnetism and diamagnetism of oxygen molecules and nitrogen molecules, and with the mutual cooperation of the magnetic field and the poly-magnetic medium, the oxygen-enriched effect of simple membrane separation is greatly improved. For the membrane separation module in the oxygen-enriched combustion gas supply system of the present invention, flue gas rich in CO2 is selected as the purge gas for the membrane separation module, directly realizing the mixed combustion of CO2-rich flue gas and O2-rich gas, solving the problems of low oxygen-enriched efficiency of the existing magnetic method and difficulty in detaching oxygen from the enrichment magnetic field, and the entire oxygen-enriched gas supply process is continuous and stable.

To provide a burner that uses ammonia as fuel and can secure radiation intensity and flame stability.SOLUTION: A burner uses fuel gas containing ammonia and combustion supporting gas of which oxygen concentration is 30% or greater, thermally decomposes part or all of the ammonia into nitrogen molecules and hydrogen molecules and burns the fuel gas in the state where the thermal decomposition has been performed.SELECTED DRAWING: Figure 1

The invention discloses a preparation method of an n-n type NiO / beta-Bi2O3 heterojunction catalyst and application of the n-n type NiO / beta-Bi2O3 heterojunction catalyst in the process of electrocatalytic nitrogen reduction synthesis of ammonia (NRR), and belongs to the technical field of electrocatalytic materials. The n-n type NiO / beta-Bi2O3 heterojunction catalyst with excellent catalytic activity and stability is successfully prepared by mixing the prepared NiO rich in oxygen vacancies with a beta-Bi2O3 precursor solution and carrying out hydrothermal and programmed heating calcination. The synergistic effect of the two effectively improves the selectivity of nitrogen reduction and reduces the incidence rate of side reactions. By constructing an n-n type heterojunction structure and utilizing an electric field effect generated by a heterojunction interface, the adsorption capacity of nitrogen molecules on the surface of the catalyst is remarkably enhanced, so that the catalytic efficiency of a nitrogen reduction reaction is improved. Compared with a traditional single catalyst, the catalyst shows higher ammonia yield and better stability, and has a wide application prospect.

The invention discloses an oxygen enrichment membrane assembly and an oxygen enrichment machine, the oxygen enrichment membrane assembly comprises a shell and a membrane layer, the membrane layer is an oxygen enrichment membrane, a mounting cavity is formed in the shell, the membrane layer is arranged in the mounting cavity of the shell, and the membrane layer is connected with the shell and divides the mounting cavity into a membrane inner cavity and a membrane outer cavity; a first vent hole and a second vent hole which are communicated with the membrane outer cavity are formed in the shell, and an airflow channel flowing through the outer surface of the membrane layer is formed between the first vent hole and the second vent hole, so that nitrogen molecules attached to the outer surface of the membrane layer are discharged out of the membrane outer cavity along the airflow channel; the membrane inner cavity is communicated with a negative pressure device in a sealed mode, and the negative pressure device is used for driving air to enter the membrane inner cavity from the membrane outer cavity through the membrane layer. The airflow channel flowing through the outer surface of the membrane layer is formed between the first vent hole and the second vent hole which are communicated with the outside of the membrane, nitrogen molecules attached to the outer surface of the membrane layer are discharged through airflow of the airflow channel, and the situation that the oxygen separation efficiency is reduced due to the fact that the nitrogen molecules block the membrane layer is avoided.

The invention relates to the technical field of molecular sieve adsorption materials, in particular to a Li-SAPO-RHO molecular sieve as well as a preparation method and application thereof. The crystal framework of the molecular sieve is silicoaluminophosphate with an RHO topological structure; in the composition of the molecular sieve framework, the molar ratio of SiO2 to Al2O3 is 0.02 to 0.5; the Li-SAPO-RHO molecular sieve has the advantages that the Li content of the Li-SAPO-RHO molecular sieve is as low as 0.2-2.0%, and the relatively low Li is located at a framework orifice of the molecular sieve to form an alkali metal cation hinge gate effect, so that the adsorption effect on nitrogen molecules is increased. The molar ratio of SiO2 / Al2O3 in a molecular sieve framework is as low as 0.02-0.5, the lower molar ratio of silicon to aluminum is beneficial for the molecular sieve to still keep higher crystallinity after high-temperature roasting, the crystallinity is up to 99% or above, the specific surface area is up to 800 m < 2 > / g, and the molecular sieve can be used as an adsorbent for preparing high-purity nitrogen through pressure swing adsorption.

The utility model discloses a gas station oil tank nitrogen injection device which comprises an oil tank body, a gas inlet pipe penetrates through a gas inlet, nitrogen enters the oil tank body along the gas inlet pipe, oil gas in the oil tank body is completely exhausted, and the oil tank body is cleaned. The end, located in the oil tank body, of the gas inlet pipe is connected with a gas acceleration cavity, the gas acceleration cavity is of a circular-truncated-cone-shaped cavity structure, when nitrogen enters the oil tank body through the gas inlet pipe, the nitrogen passes through the gas acceleration cavity, the caliber of the gas acceleration cavity is gradually reduced from top to bottom, and under the equal pressure, the nitrogen injection speed is increased in the gas acceleration cavity; nitrogen molecules can be more rapidly diffused in the tank when obtaining larger kinetic energy, so that the oil gas replacement efficiency is effectively improved; and the side wall of the gas accelerating cavity is evenly connected with the gas outlet pipes, the nitrogen is exhausted into the oil tank body from the multiple gas outlet pipes after being accelerated, exhausting is more uniform, the nitrogen diffusion comprehensiveness is improved, and the oil gas replacement efficiency is further improved.