Special molecular sieve for separating ozone from oxygen in PSA (Pressure Swing Adsorption) mode

Abstract

The invention relates to the technical field of molecular sieves, and discloses a special molecular sieve for separating ozone from oxygen in a PSA (Pressure Swing Adsorption) mode, the molecular sieve can resist ozone and has strong oxidizing property, has strong adsorbability to ozone under certain pressure and does not adsorb oxygen; the molecular sieve components comprise silicon dioxide, aluminum oxide, a composite metal oxide and silicate, and the composite metal oxide is composed of a transition metal oxide and a rare earth metal oxide; the special molecular sieve prepared by the invention can obviously improve the separation efficiency of ozone. Through unique component matching, by controlling the proportion of silicon dioxide, aluminum oxide, composite metal oxide and silicate and matching with a special crystal structure, the material has extremely high adsorbability to ozone under a certain pressure, but hardly adsorbs oxygen, which means that in practical application, the material can be used for preparing a novel material. High-concentration ozone can be obtained with low energy consumption and cost, and the use efficiency of ozone in various industries is greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of molecular sieves, and specifically to a special molecular sieve for separating ozone and oxygen by PSA pressure swing adsorption method. Background Art

[0002] In the modern industrial production system, ozone has a very wide range of application fields. Many industries, from sewage treatment, food processing disinfection to fine chemical synthesis, rely on the strong oxidizing property of ozone to achieve specific production goals. As one of the main sources of ozone, industrial ozone generators with an oxygen source mostly produce a mixed gas of ozone and oxygen. The ozone concentration is usually about 148 mg / L, which is a mixture of about 10% ozone and 90% oxygen. Such low-concentration ozone has many limitations in practical applications. In the field of sewage treatment, to achieve ideal disinfection and pollutant degradation effects, more ozone needs to be input, which not only increases the energy consumption of ozone production but also prolongs the treatment time. In the food processing disinfection process, low-concentration ozone may not be able to completely kill harmful microorganisms, affecting food safety, and increasing the ozone concentration faces the problem of a sharp increase in costs. At the same time, a large amount of unutilized oxygen is directly discharged, which not only causes waste of resources but also increases production costs.

[0003] As a key material in the field of gas separation, molecular sieves have been widely studied and applied in the past few decades. Traditional molecular sieves are mainly used in processes such as drying and purifying gases and catalytic cracking in petrochemical industry. However, for the separation of ozone and oxygen mixed gas, traditional molecular sieves have obvious limitations. The pore size distribution and surface properties of ordinary molecular sieves make it difficult to selectively adsorb ozone and cannot achieve efficient separation. Some molecular sieves with certain adsorption properties have poor structural stability in the strong oxidizing environment of ozone, are prone to degradation and inactivation, resulting in short service life and high cost.

[0004] Existing gas separation technologies also have many problems when dealing with ozone and oxygen mixed gas. For example, the cryogenic distillation method can theoretically separate the two, but this method requires extremely low temperatures and high-pressure conditions, with large and complex equipment, extremely high energy consumption, strict process requirements, and investment and operating costs that are difficult for many enterprises to bear. Although the membrane separation technology is relatively simple to operate, its separation efficiency is limited and it is difficult to meet the requirements of large-scale industrial production for high-purity ozone and oxygen.

[0005] Therefore, it is of great significance to develop a technology that can efficiently separate ozone and oxygen, increase the ozone concentration and realize the recycling of oxygen. Summary of the Invention

[0006] In view of the problems in the prior art, the present invention provides a special molecular sieve for separating ozone and oxygen by PSA pressure swing adsorption.

[0007] The technical solution adopted by the present invention to solve its technical problems is: a special molecular sieve for separating ozone and oxygen by PSA pressure swing adsorption, the molecular sieve can withstand the strong oxidizing property of ozone, has strong adsorption capacity for ozone under a certain pressure and does not adsorb oxygen;

[0008] The components of the molecular sieve are calculated by weight percentage, including 30-45% of silicon dioxide, 15-25% of aluminum oxide, 5-15% of composite metal oxide, and the balance of silicate. The composite metal oxide is composed of transition metal oxide and rare earth metal oxide;

[0009] Silicon dioxide, aluminum oxide, composite metal oxide and silicate cooperate with each other to form a stable structure with special adsorption properties. The transition metal oxide and rare earth metal oxide in the composite metal oxide can introduce special active sites in the crystal structure, enhance the adsorption capacity of the molecular sieve for ozone, and at the same time do not adsorb oxygen. This characteristic enables the molecular sieve to selectively adsorb ozone in the separation of ozone and oxygen mixed gas, realizing the efficient separation of the two.

[0010] As a further technical solution, the transition metal oxide is copper oxide and zinc oxide;

[0011] The mass ratio of copper oxide to zinc oxide is 3-4:1; copper oxide and zinc oxide can form a specific microstructure in the molecular sieve structure, enhancing the adsorption affinity for ozone molecules. At the same time, the appropriate ratio ensures the synergistic effect between the two oxides, making the molecular sieve more stable when adsorbing ozone, significantly improving the adsorption capacity and adsorption rate of the molecular sieve for ozone, and thus enhancing the overall separation efficiency.

[0012] As a further technical solution, the rare earth metal oxide is cerium oxide and lanthanum oxide;

[0013] The mass ratio of cerium oxide to lanthanum oxide is 2:1-1.2; the rare earth metal oxide is selected as cerium oxide and lanthanum oxide. Cerium oxide and lanthanum oxide can adjust the surface acidity and basicity and electronic properties of the crystal in the molecular sieve, further optimizing the adsorption performance of the molecular sieve for ozone. At this ratio, cerium oxide and lanthanum oxide cooperate with each other, effectively enhancing the redox ability of the molecular sieve, making ozone more likely to interact with the surface of the molecular sieve during the adsorption process, thereby improving the adsorption selectivity and stability for ozone. This optimized ratio helps to more stably separate ozone and oxygen in a complex industrial environment, reducing the influence of impurity gases on the separation effect.

[0014] As a further technical solution, the method for preparing the special molecular sieve comprises the following steps:

[0015] Crush the silicate ore to 200 - 300 mesh, weigh the silicate, silica, alumina powder and nitrate compounds containing composite metal elements, and prepare the nitrate compounds into a metal ion solution; each step of this preparation method is closely coordinated to jointly shape the excellent performance of the molecular sieve. Crushing the silicate ore increases the specific surface area of the raw materials, enabling them to participate more fully in subsequent reactions and ensuring uniform mixing of all components. Preparing the nitrate compounds into a metal ion solution is conducive to the uniform distribution of the composite metal elements in the molecular sieve, ensuring effective regulation of its adsorption performance;

[0016] Mix the above powders and the metal ion solution evenly, then add a binder and a pore-forming agent, and after stirring, extrude and form to obtain a molecular sieve precursor;

[0017] Adding a binder and a pore-forming agent, the binder can enhance the binding force between components and ensure the structural stability of the molecular sieve; the pore-forming agent decomposes during calcination to form a uniform microporous structure, increasing the specific surface area and improving the adsorption capacity;

[0018] Dry the molecular sieve precursor at 112 - 120 °C for 8 - 10 hours, and then heat it to 550 - 700 °C at a heating rate of 2 - 3 °C / min and calcine for 3 - 4 hours; the drying and calcination processes further optimize the crystal structure of the molecular sieve, making it more stable and enhancing its adsorption performance for ozone;

[0019] Cool the calcined molecular sieve to room temperature, then completely soak it in a silane coupling agent solution with a mass fraction of 5 - 5.8% according to a liquid-to-solid ratio of 1:10 - 12 for 1 - 1.5 hours, and dry it at 80 - 90 °C for 3 - 4 hours to obtain; the final treatment with the silane coupling agent improves the surface properties of the molecular sieve, enhances its water resistance and chemical stability, and extends its service life.

[0020] As a further technical solution, the binder is pseudo-boehmite, and the dosage of the binder is 4 - 4.6% of the total mass of the raw materials; choosing pseudo-boehmite as the binder is because pseudo-boehmite undergoes a phase change during heating to generate alumina, which can not only enhance the binding force between raw materials but also form chemical bonds with other components in the molecular sieve, further stabilizing the structure of the molecular sieve. Within this dosage range, it can ensure the tight combination of all components without blocking the pores of the molecular sieve due to excessive binder, thus affecting its adsorption performance. This precise dosage control helps to prepare a molecular sieve with stable structure and good adsorption performance, improving product quality and stability;

[0021] As a further technical solution, the pore former is polyethylene glycol, and the dosage of the pore former is 3-4% of the total mass of the raw materials; polyethylene glycol as a pore former plays a key role in the preparation process. During the calcination process, polyethylene glycol decomposes and volatilizes, leaving uniformly distributed pores. The size and number of these pores directly affect the specific surface area and adsorption performance of the molecular sieve. This dosage range can form micropores with appropriate size and moderate quantity, which is beneficial to the diffusion and adsorption of ozone molecules, while ensuring the mechanical strength of the molecular sieve. If the dosage of the pore former is too much or too little, it will lead to an unsatisfactory pore structure, thereby reducing the adsorption efficiency and separation effect of the molecular sieve.

[0022] As a further technical solution, during the extrusion molding, the screw speed is 20-25 r / min, and the extrusion pressure is 2-3 MPa; under these parameters, the mixed raw materials can be evenly distributed in the mold to form a molecular sieve precursor with uniform texture. Appropriate screw speed and extrusion pressure ensure the density and shape stability of the precursor, avoiding internal defects or uneven structures. This uniform structure is beneficial to the uniform transfer of heat and the migration of substances during the subsequent drying and calcination processes, further promoting the formation and improvement of the molecular sieve crystal structure, and ultimately improving the adsorption performance and mechanical strength of the molecular sieve, ensuring stable and efficient operation in practical applications.

[0023] As a further technical solution, a method for separating ozone and oxygen using a special molecular sieve includes the following steps: introducing a mixed gas of ozone and oxygen into a separation device composed of 2-8 adsorption towers and a buffer tank;

[0024] In the adsorption tower, ozone is adsorbed by the molecular sieve, and oxygen flows out and enters the buffer tank; when the molecular sieve in the adsorption tower reaches adsorption saturation, the pressure in the adsorption tower is reduced to 0.1-0.2 MPa to desorb ozone, and the desorbed ozone is collected and utilized;

[0025] Control the switching of adsorption and desorption of the adsorption tower, with the adsorption time being 20-30 minutes and the desorption time being 5-8 minutes.

[0026] As a further technical solution, the flow rate of the mixed gas of ozone and oxygen entering the adsorption tower is 0.3-0.5 m 3 / h; this flow rate range is determined by comprehensively considering factors such as the adsorption capacity of the molecular sieve, the processing capacity of the adsorption tower, and the separation efficiency. If the flow rate is too low, the production efficiency will be reduced; if the flow rate is too high, the contact time between the mixed gas and the molecular sieve will be too short, and ozone will flow out of the adsorption tower before being fully adsorbed, reducing the separation effect. Within this flow rate range, the mixed gas can fully contact the molecular sieve, enabling the molecular sieve to effectively adsorb ozone, while ensuring the stability and efficiency of the entire separation process, which is conducive to realizing large-scale industrial production.

[0027] Advantages of the present invention:

[0028] The special molecular sieve prepared by the present invention can significantly improve the separation efficiency of ozone. Through unique component combination, by controlling the proportions of silica, alumina, composite metal oxides, and silicate, and combined with a special crystal structure, it has extremely strong adsorption capacity for ozone under a certain pressure, while hardly adsorbing oxygen. This means that in practical applications, high-concentration ozone can be obtained with lower energy consumption and costs, greatly improving the utilization efficiency of ozone in various industries.

[0029] In the process of preparing the molecular sieve, each step plays a key role, jointly ensuring the performance of the molecular sieve. Crushing the silicate ore increases the specific surface area of the raw materials, enabling them to participate more fully in the subsequent reactions and promoting the uniform mixing of various components. Accurately weighing various raw materials and preparing nitrate compounds into metal ion solutions ensure the uniform distribution of composite metal oxides in the molecular sieve, enhancing the adsorption selectivity and stability of the molecular sieve for ozone. Adding the binder pseudo-boehmite and the pore-forming agent polyethylene glycol, during the mixing and forming process, pseudo-boehmite enhances the bonding force between various components, ensuring the structural stability of the molecular sieve during use; polyethylene glycol decomposes and volatilizes during the calcination process, forming a uniform microporous structure, increasing the specific surface area of the molecular sieve, and improving the adsorption capacity. The drying and calcination steps further optimize the crystal structure of the molecular sieve, enabling it to remain stable in the strong oxidizing environment of ozone and extending its service life.

[0030] The present invention not only realizes the efficient separation of ozone, but also can recycle and reuse the separated oxygen. Through the PSA pressure swing adsorption method, while separating ozone, relatively high-purity oxygen is collected, avoiding the waste of oxygen. The separated oxygen has a relatively high purity, and these recycled oxygen can be reapplied to other links of industrial production, such as being used as a combustion-supporting agent, reducing the enterprise's dependence on external oxygen supply, further saving production costs, and realizing the efficient utilization of resources. Detailed implementation manners

[0031] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0032] The present invention provides a special molecular sieve for separating ozone and oxygen by the PSA pressure swing adsorption method, its preparation method and separation method, and the specific content is as follows:

[0033] Composition and Characteristics of Special Molecular Sieve: The special molecular sieve of the present invention can withstand the strong oxidizing property of ozone, has strong adsorption of ozone under a certain pressure and does not adsorb oxygen. Its composition by weight percentage includes 30-45% of silicon dioxide, 15-25% of aluminum oxide, 5-15% of composite metal oxide, and the balance of silicate. Among them, the composite metal oxide is composed of transition metal oxide and rare earth metal oxide. The transition metal oxide is copper oxide and zinc oxide, and the mass ratio of the two is 3-4:1; the rare earth metal oxide is cerium oxide and lanthanum oxide, and the mass ratio of cerium oxide to lanthanum oxide is 2:1-1.2.

[0034] Preparation Method of Special Molecular Sieve

[0035] Raw Material Pretreatment: Select appropriate silicate ore and crush it to 200-300 mesh. According to the formula ratio, accurately weigh silicate, silicon dioxide, aluminum oxide powder, and nitrate compound containing composite metal elements. Dissolve the nitrate compound in an appropriate amount of deionized water to prepare a metal ion solution.

[0036] Mixing and Shaping: Add the weighed silicate, silicon dioxide, and aluminum oxide powders into a stirring device and stir evenly. Then slowly add the prepared metal ion solution and continue stirring to fully mix the solution and the powders. Next, add binder pseudoboehmite and pore-forming agent polyethylene glycol. The dosage of the binder is 4-4.6% of the total mass of the raw materials, and the dosage of the pore-forming agent is 3-4% of the total mass of the raw materials. Continue stirring for a period of time to ensure that all components are evenly mixed. Put the obtained mixture into an extrusion molding device, set the screw rotation speed to 20-25 r / min, and the extrusion pressure to 2-3 MPa to extrude and form a molecular sieve precursor.

[0037] Drying and Calcination: Put the molecular sieve precursor into an oven and dry it at a temperature of 112-120 °C for 8-10 hours to remove the moisture. Transfer the dried precursor to a muffle furnace and heat it to 550-700 °C at a heating rate of 2-3 °C / min and calcine it for 3-4 hours to cause physical and chemical changes in the precursor to form a stable molecular sieve structure.

[0038] Post-treatment: The calcined molecular sieve is naturally cooled to room temperature, and then put it into a silane coupling agent solution with a mass fraction of 5-5.8%, and mix and soak it completely at a material-liquid ratio of 1:10-12 for 1-1.5 hours. After soaking, take it out and dry it in an oven at 80-90 °C for 3-4 hours to obtain the final special molecular sieve product.

[0039] Method for Separating Ozone and Oxygen by Using Special Molecular Sieve: Build a separation device composed of 2-8 adsorption towers and a buffer tank. Feed the mixed gas of ozone and oxygen at a flow rate of 0.3-0.5 m 3The flow rate of / h is introduced into the adsorption tower in the separation device. In the adsorption tower, due to the characteristics of the special molecular sieve, ozone is adsorbed by the molecular sieve, while oxygen flows out and enters the buffer tank. When the molecular sieve in the adsorption tower reaches adsorption saturation, the pressure in the adsorption tower is reduced to 0.1 - 0.2 MPa to desorb the adsorbed ozone, and the desorbed high-concentration ozone gas is collected and utilized. Through the control device, the adsorption and desorption switching of the adsorption tower is precisely controlled. The adsorption time is set to 20 - 30 minutes, and the desorption time is set to 5 - 8 minutes to achieve continuous and efficient separation of ozone and oxygen.

[0040] To further illustrate the present invention, the following detailed description is provided through the following examples. The raw materials such as silicate ore, silica, alumina powder, nitrate compounds containing composite metal elements, pseudoboehmite, polyethylene glycol, and silane coupling agent used in the following examples of the present invention are all commercially available conventional products;

[0041] The following are specific examples:

[0042] Example 1

[0043] Preparation of special molecular sieve

[0044] Raw material preparation: The silicate ore is crushed to 200 meshes, and 32% of silicate, 42% of silica, and 20% of alumina powder are weighed. An appropriate amount of nitrate compounds containing copper, zinc, cerium, and lanthanum elements are weighed and formulated into a metal ion solution, in which the mass ratio of copper oxide to zinc oxide is 3.2:1, and the mass ratio of cerium oxide to lanthanum oxide is 2:1.1.

[0045] Mixing and forming: After the powders are mixed evenly, the metal ion solution is added and stirred evenly. 4.3% of pseudoboehmite and 3.2% of polyethylene glycol based on the total mass of the raw materials are added, and extrusion forming is carried out at a screw speed of 22 r / min and an extrusion pressure of 2.3 MPa.

[0046] Drying and calcination: Drying is carried out at 116°C for 8.5 hours, and the temperature is raised to 620°C at a rate of 2.2°C / min and calcined for 3.2 hours.

[0047] Post-treatment: After cooling, it is soaked in a 5.2% mass fraction silane coupling agent solution at a material-liquid ratio of 1:10.5 for 1.3 hours and dried at 86°C for 3.3 hours.

[0048] Separation of ozone and oxygen: A separation device composed of 5 adsorption towers and a buffer tank is used. The flow rate of the mixed gas is 0.4 m 3 / h, the adsorption time is 23 minutes, the desorption pressure is 0.13 MPa, and the desorption time is 6.5 minutes.

[0049] Example 2

[0050] Preparation of special molecular sieve

[0051] Raw material preparation: The silicate ore is crushed to 250 mesh, and 35% of silicate, 40% of silicon dioxide, and 18% of aluminum oxide powder are weighed. A metal ion solution is prepared, and the mass ratio of copper oxide to zinc oxide is 3.5:1, and the mass ratio of cerium oxide to lanthanum oxide is 2:1.

[0052] Mixing and forming: The mixed powder and the solution are added with 4.5% of pseudoboehmite and 3.5% of polyethylene glycol, the screw speed is 23 r / min, and the extrusion pressure is 2.5 MPa for forming.

[0053] Drying and calcination: Drying at 118 °C for 9 hours, heating to 650 °C at a rate of 2.5 °C / min, and calcining for 3.5 hours.

[0054] Post-treatment: Immerse in a 5.5% silane coupling agent solution at a liquid-solid ratio of 1:11 for 1.2 hours, and dry at 88 °C for 3.5 hours.

[0055] Separation of ozone and oxygen: Use a 6-tower adsorption device, the flow rate of the mixed gas is 0.45 m 3 / h, the adsorption time is 26 minutes, the desorption pressure is 0.15 MPa, and the desorption time is 7 minutes.

[0056] Example 3

[0057] Preparation of special molecular sieve

[0058] Raw material preparation: The ore is crushed to 280 mesh, and 38% of silicate, 38% of silicon dioxide, and 16% of aluminum oxide powder are weighed. In the metal ion solution, the mass ratio of copper oxide to zinc oxide is 3.8:1, and the mass ratio of cerium oxide to lanthanum oxide is 2:1.2.

[0059] Mixing and forming: Add 4.1% of pseudoboehmite and 3.8% of polyethylene glycol, the screw speed is 21 r / min, and the extrusion pressure is 2.2 MPa for forming.

[0060] Drying and calcination: Drying at 114 °C for 9.5 hours, heating to 580 °C at a rate of 2.3 °C / min, and calcining for 3.8 hours.

[0061] Post-treatment: Immerse in a 5.3% silane coupling agent solution at a liquid-solid ratio of 1:11.5 for 1.4 hours, and dry at 82 °C for 3.7 hours.

[0062] Separation of ozone and oxygen: Set up a 4-tower adsorption device, the flow rate of the mixed gas is 0.35 m 3 / h, the adsorption time is 28 minutes, the desorption pressure is 0.12 MPa, and the desorption time is 7.5 minutes.

[0063] Example 4

[0064] Preparation of special molecular sieve

[0065] Raw material preparation: The silicate ore is crushed to 300 meshes, and 40% of silicate, 35% of silicon dioxide, and 15% of aluminum oxide powder are weighed. A metal ion solution is prepared, and the mass ratio of copper oxide to zinc oxide is 4:1, and the mass ratio of cerium oxide to lanthanum oxide is 2:1.1.

[0066] Mixing and forming: 4.6% of pseudo-boehmite and 3% of polyethylene glycol are added, the screw speed is 24 r / min, and the extrusion pressure is 2.8 MPa for forming.

[0067] Drying and calcination: Drying at 120 °C for 8 hours, heating to 700 °C at a rate of 3 °C / min, and calcining for 3 hours.

[0068] Post-treatment: Immerse in a 5.8% silane coupling agent solution at a liquid-to-solid ratio of 1:12 for 1 hour, and dry at 90 °C for 3 hours.

[0069] Separation of ozone and oxygen: A 7-tower adsorption device is used, the flow rate of the mixed gas is 0.5 m 3 / h, the adsorption time is 20 minutes, the desorption pressure is 0.2 MPa, and the desorption time is 5 minutes.

[0070] Comparative Example 1

[0071] An ozone and oxygen separation test is carried out using a common molecular sieve on the market (HYS-13X type molecular sieve of Shanghai Hengye Molecular Sieve Co., Ltd.), and the separation device and operating conditions are the same as those in Example 2.

[0072] Comparative Example 2

[0073] When preparing the molecular sieve, the composite metal compound is not added, and other preparation conditions and separation operations are the same as those in Example 3.

[0074] Test

[0075] Ozone recovery rate test

[0076] Refer to the GB method: Conduct according to the relevant method for ozone content determination in GB / T 23499-2009 "Analysis Method for Hygienic Standards of Polyvinyl Chloride Molding Products for Food Packaging";

[0077] Test process: The ozone separated in the examples and comparative examples is collected respectively, the ozone content is measured by chemical titration, and the ozone recovery rate is calculated;

[0078] Oxygen purity test

[0079] Refer to the GB method: Conduct according to the method for gas purity detection in GB / T 3634.2-2011 "Pure Hydrogen, High-Purity Hydrogen and Ultra-High-Purity Hydrogen - Part 2: Purity Analysis Method";

[0080] Test procedure: Use a gas chromatograph to analyze the purity of the separated oxygen;

[0081] The adsorption capacity can be determined by referring to the detection method in GB / T 7702.20-2008 "Test Methods for Coal-based Granular Activated Carbon - Determination of Benzene Vapor Adsorption Capacity":

[0082] Table 1

[0083]

[0084] As can be seen from Table 1, the molecular sieve prepared by the present invention can effectively separate ozone and oxygen.

[0085] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A special molecular sieve for separating ozone and oxygen by PSA pressure swing adsorption, characterized in that: The molecular sieve is resistant to the strong oxidizing property of ozone, has strong adsorption to ozone under a certain pressure and does not adsorb oxygen; The molecular sieve components include 30-45% silicon dioxide, 15-25% aluminum oxide, 5-15% composite metal oxide and the remainder silicate by weight, wherein the composite metal oxide is composed of transition metal oxide and rare earth metal oxide.

2. The special molecular sieve for separating ozone and oxygen by PSA pressure swing adsorption according to claim 1, characterized in that: The transition metal oxides are copper oxide and zinc oxide; The mass ratio of copper oxide to zinc oxide is 3-4:

1.

3. The special molecular sieve for separating ozone and oxygen by PSA pressure swing adsorption according to claim 1, characterized in that: The rare earth metal oxides are cerium oxide and lanthanum oxide; The mass ratio of cerium oxide to lanthanum oxide is 2:1-1.

2.

4. The special molecular sieve for separating ozone and oxygen by PSA pressure swing adsorption according to claim 1, characterized in that: The method for preparing the special molecular sieve comprises the following steps: The silicate ore is crushed to 200-300 meshes, silicate, silicon dioxide, aluminum oxide powder and nitrate compound containing composite metal elements are weighed, and the nitrate compound is prepared into a metal ion solution; The powder and metal ion solution are mixed evenly, and then a binder and a pore-forming agent are added, and the mixture is stirred and extruded to obtain a molecular sieve precursor; The molecular sieve precursor is dried at 112-120°C for 8-10 hours, and then heated to 550-700°C at a heating rate of 2-3°C / min and calcined for 3-4 hours; The calcined molecular sieve is cooled to room temperature, and then mixed with a silane coupling agent solution with a mass fraction of 5-5.8% in a material-liquid ratio of 1:10-12 for complete immersion for 1-1.5 hours, and dried at 80-90° C. for 3-4 hours to obtain.

5. The special molecular sieve for separating ozone and oxygen by PSA pressure swing adsorption according to claim 4, characterized in that: The binder is pseudo-boehmite, and the amount of the binder is 4-4.6% of the total mass of the raw materials.

6. The special molecular sieve for separating ozone and oxygen by PSA pressure swing adsorption according to claim 4, characterized in that: The pore-forming agent is polyethylene glycol, and the amount of the pore-forming agent is 3-4% of the total mass of the raw materials.

7. The special molecular sieve for separating ozone and oxygen by PSA pressure swing adsorption according to claim 4, characterized in that: During the extrusion molding, the screw speed is 20-25r / min and the extrusion pressure is 2-3MPa.

8. A special molecular sieve for separating ozone and oxygen by PSA pressure swing adsorption according to any one of claims 1 to 7, characterized in that: The method for separating ozone and oxygen using a special molecular sieve comprises the following steps: passing a mixed gas of ozone and oxygen into a separation device consisting of 2-8 adsorption towers and a buffer tank; In the adsorption tower, ozone is adsorbed by the molecular sieve, and oxygen flows out into the buffer tank; when the molecular sieve in the adsorption tower reaches adsorption saturation, the pressure in the adsorption tower is reduced to 0.1-0.2MPa to desorb ozone, and the desorbed ozone is collected and utilized; The adsorption and desorption switching of the adsorption tower is controlled, with the adsorption time being 20-30 minutes and the desorption time being 5-8 minutes.

9. The special molecular sieve for separating ozone and oxygen by PSA pressure swing adsorption according to claim 7, characterized in that: The flow rate of the mixed gas of ozone and oxygen entering the adsorption tower is 0.3-0.5m 3 / h.

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