A full temperature range simulated rotating moving bed pressure swing adsorption (FTrSRMPSA) air separation nitrogen production process

Abstract

The invention discloses an air separation nitrogen production process of full-temperature simulated rotating moving bed pressure swing adsorption (FTrSRMPSA), in which a plurality of axial flow fixed bed adsorption towers are placed in the center of a multi-channel rotary valve and arranged on a circular rotating tray around the valve, and are connected through pipelines and the rotating direction and speed (ω1) of the rotary valve and the rotating direction and speed (ω2) of the circular rotating tray are regulated, so that the gas flowing through the rotating adsorption bed layer in the adsorption tower continuously passes through the positions of the inlet and outlet of each adsorption tower and each adsorption bed layer completes the mass transfer of its own adsorption and desorption steps while rotating, thereby realizing the simulated rotating moving bed pressure swing adsorption process based on the axial flow fixed bed pressure swing adsorption, so that the adsorption and desorption multi-step cyclic operation is performed, and the nitrogen product gas with a purity of 96-99.9% and a yield of 50-70% is obtained from the air.

Description

Technical Field

[0001] The present invention relates to the technical field of pressure swing adsorption (PSA) for separating and preparing pure nitrogen from air, and more specifically to an air separation nitrogen production process of full temperature range simulated rotating moving bed pressure swing adsorption (FTrSRMPSA). Background Art

[0002] There are two main industrial production methods for nitrogen (N2): cryogenic air distillation (cryogenic air separation) and pressure swing adsorption. Membrane separation is uneconomical and not commonly used for nitrogen production. Cryogenic air distillation is mainly suitable for large-scale pure nitrogen preparation, and can simultaneously produce high-purity oxygen (N2) and argon (Ar) as byproducts. For small-scale nitrogen production equipment, its unit energy consumption is high, construction investment is large, and nitrogen production costs are high; pressure swing adsorption (PSA) is currently the most widely used method for air separation nitrogen production of various scales in some chemical industries.

[0003] There are significant differences between the PSA air separation nitrogen production process and the PSA air separation oxygen enrichment process. The adsorption mechanism of air separation oxygen enrichment is mainly equilibrium adsorption. Nitrogen (N2), carbon dioxide (CO2), water and trace hydrocarbons (C m H n ) as adsorbents, oxygen (O2) and argon (Ar) as non-adsorbed phase components, commonly used adsorbents include 5A, 13X, LiX, etc. Among them, LiX-type adsorbents have a large N2 adsorption capacity, and the O2 / N2 relative adsorption separation coefficient on the adsorbent is also relatively large, which is very suitable for air separation oxygen enrichment. When N2 is produced from air, two different adsorption mechanisms and corresponding PSA processes are formed because two types of molecular sieves can be used. One is based on the equilibrium separation mechanism, using 5A and other equilibrium molecular sieves as adsorbents to extract N2 products from the adsorption phase, that is, nitrogen (N2), carbon dioxide (CO2), water and trace hydrocarbons (C m H n ) as adsorbents, and the adsorption mechanism is the same as the air separation oxygen enrichment process. Obviously, since 70% of the N2 in the air is used as adsorbent to obtain products from the adsorption phase, the cost and energy consumption are naturally very high. Therefore, the PSA air separation nitrogen production process based on the equilibrium adsorption mechanism is generally economically beneficial when PSA air separation oxygen enrichment is co-produced; the other is a process based on the kinetic separation mechanism, which uses carbon molecular sieve (CMSN2) as an adsorbent to extract products from the gas phase, that is, N2 and Ar are used as non-adsorbed phase components, while O2 and trace amounts of CO2, water, etc. are used as adsorbent components. The PSA air separation nitrogen production process based on the kinetic adsorption mechanism is simple and has low energy consumption. It has been widely used at home and abroad.

[0004] The basic characteristics of carbon molecular sieve (CMSN2) PSA air separation nitrogen production are: first, the equilibrium adsorption capacity for oxygen and nitrogen is very close, and the amount of oxygen adsorbed is slightly greater than that of nitrogen. The property is more similar to activated carbon, and oxygen and nitrogen cannot be separated; second, due to the slit-shaped micropores of carbon molecular sieve (CMSN2), which are different from the bottleneck-shaped micropores of zeolite molecular sieves, the diffusion rate of oxygen is much faster than that of nitrogen in a short time after the adsorption begins. This difference in diffusion rate makes oxygen a component that is preferentially adsorbed even at very low equilibrium selectivity, so that a large amount of oxygen is adsorbed to achieve the purpose of separation. After a few minutes of adsorption, the equilibrium adsorption capacity of oxygen has reached 80% of the saturation value, while the adsorption capacity of nitrogen is less than 5% in the same time; third, the molecular diameters of H2O and CO2 in the air are both 0.28nm, which are adsorbed together with oxygen, but have almost no effect on the adsorption capacity of oxygen, while the molecular diameter of Ar is 3.83nm, which is enriched in the gas phase together with nitrogen. Based on the kinetic mechanism of N2 adsorption separation, the typical PSA process includes a BF-PSA cycle process, that is, two axial flow fixed bed adsorption towers, adsorption under high pressure, and extraction of pure nitrogen; equalization of pressure between the two beds; including reverse pressure reduction for product flushing, during which the waste gas is vented; pressurizing the bed with raw gas from the raw material end and product gas from the product end. In the adsorption step, the length of the adsorption time is very important. In the first minute, the relative adsorption capacity of oxygen is significantly greater than that of nitrogen, and the biggest difference is between the first and second minutes. If the time is too long, equilibrium will be reached and selectivity will be lost. If the time is too short, the adsorption will be insufficient. The optimal adsorption time (half cycle time) is about 60s. The PSA device for air separation nitrogen production has great operational flexibility. By adjusting the flow rate, it is easy to control the purity of the nitrogen product from 95% to 99.9% (v), of which the argon content varies between 1.2% and 1.5%, the gas dew point is about -40℃, and the nitrogen recovery rate is about 50% to 29%. The lower the oxygen content in the product is, the lower the product recovery rate is and the higher the energy consumption is. Therefore, the biggest technical challenge of axial flow fixed bed PSA air separation nitrogen production is the prominent "contradiction between purity and yield", and the control of adsorption time plays a key role in air separation nitrogen production. If the air raw gas fluctuates, especially CO2, H2O and trace hydrocarbons (C m H n) components and impurity components such as compressor oil are mixed into the PSA adsorption tower. For the BF-PSA air separation nitrogen production of the 2-tower, its adaptability is relatively poor, and it can only be dealt with by reducing the purity, yield or processing volume of the product nitrogen, resulting in a significant reduction in the service life of the adsorbent. In addition, when the required oxygen content in the nitrogen product is controlled to less than 0.1%, it is necessary to use chemical methods to remove it, such as using palladium metal catalysts and adding hydrogen to allow trace amounts of oxygen to react with the hydrogen added to achieve deoxidation, which can make the oxygen concentration in the nitrogen product gas less than 1ppmv, but the residual hydrogen content in the nitrogen is about 0.1%~1%, and the gas dew point will be lower than 0℃, which can be used as a protective agent for welding and annealing operations. If further adsorption and drying are performed, low dew point high purity nitrogen can be obtained, such as using activated carbon or carbon fiber or carbon nanotube loaded catalyst or copper catalyst for deoxidation. In a sense, the most critical factor affecting the performance of the axial flow fixed bed PSA air separation nitrogen production process and equipment is still the performance of the adsorbent. Therefore, the current research and development in the field of air separation nitrogen production in China is mostly focused on how to produce better quality nitrogen production carbon molecular sieves (CMSN2). At present, the specific nitrogen production rate of the best foreign carbon molecular sieves has improved in the low purity nitrogen range (97%~99.5%). Compared with foreign carbon molecular sieves, there is still a certain gap in the specific nitrogen production rate and mechanical strength. There is still room for development in improving the quality of carbon molecular sieves, improving the structure of adsorption towers and developing direct production of high purity nitrogen products.

[0005] In order to overcome some defects of the fixed-bed pressure swing adsorption air separation nitrogen production process, a PSA radial flow rotor adsorption (RWPSA) process has been developed in China and abroad for air separation nitrogen production from the aspects of process, adsorption tower structure and moving bed. That is, the adsorbent is fixed in the adsorption container and does not move relative to it, but the adsorbent is rotated as a whole through the belt action of the driving mechanism, and the positions of logistics (gas) including air raw gas, reverse exhaust gas, pressurized gas, etc. entering and exiting the rotor adsorber are fixed. The cyclic operation of adsorption and desorption is carried out simultaneously in each adsorption fan-shaped chamber in different adsorbers, which makes up for the defects of the classic moving bed adsorption process that the adsorbent is easy to be consumed and cannot be applied to the PSA separation or purification process. At the same time, compared with the traditional fixed-bed PSA process, the adsorbent loading amount is greatly reduced, the adsorption efficiency is improved, the purity and yield of the product gas are improved, and to a certain extent, the technical bottleneck of "the contradiction between purity and yield" existing in the fixed-bed PSA process is broken through. However, the RWPSA process also has obvious limitations and disadvantages: First, the diameter and height (thickness) of the adsorption rotor are greatly limited, resulting in insufficient adsorption treatment scale. This is because RWPSA is essentially a moving bed. To achieve the "steady-state" mass transfer of typical moving bed adsorption processes such as circulating beds or fluidized beds, its axial mass transfer diffusion or radial mass transfer diffusion capacity must be limited. This feature is an advantage for axial flow or radial flow fixed bed processes; second, the manufacturing of the rotor PSA equipment is complex, especially the equipment with equalization, and the number of equalization times does not exceed 2 times. At present, most of them are manufactured or monopolized by foreign companies, and the cost is relatively high; third, it is more suitable for the rapid adsorption and rapid desorption of a single adsorbent component and the adsorption mechanism of the adsorbent component is mainly kinetic adsorption, such as the purification of VOCs exhaust gas. For the kinetic adsorption mechanism of air separation nitrogen production, the RWPSA process is more suitable. However, when the air contains more impurity components such as CO2, water and hydrocarbons, the adsorbent in the RWPSA process cannot form a composite bed such as a fixed bed filled with multiple adsorbents for treatment, and is particularly susceptible to water droplets in the air and other easily contaminated droplets such as those brought by the compressor; Fourth, the adsorbent in the RWPSA is prone to being thrown off due to the presence of shear force during rotation, resulting in deviation or short flow of the process flow gas in the adsorption bed, which greatly reduces the mass transfer efficiency and makes the adsorbent more easily pulverized, resulting in a shortened service life of the adsorbent. For example, application number US09584269 discloses this type of modular rotary pressure swing adsorption device, which can be constructed so that the fluid flows through the adsorber component in a radial, axial or inclined conical direction relative to the rotor axis. In order to work at a high cycle frequency, the advantage of radial flow is that the centripetal acceleration will be parallel to the flow channel to make the buoyancy-driven free convection most stable, and the centrifugal clamping of the granular adsorbent has a uniform flow distribution.The patent also has the defects of being easily damaged by water droplets and other easily contaminated droplets in the air, and the rapid cycle makes the adsorption pressure vessel and adsorbent bear greater alternating stress, etc. In the rotary pressure swing adsorption method, regular adsorbents are often used to replace granular adsorbents, which can reduce the alternating stress and loss of the adsorbent, but for air separation nitrogen production, this type of regular adsorbent is rarely reported in China. Summary of the invention

[0006] In view of some problems of the various existing fixed bed and rotary PSA air separation nitrogen production processes mentioned above, the present invention proposes a new full temperature range simulated rotary moving pressure swing adsorption (Full Temperature range Simulated Rotated Moving PSA - FTrSRMPSA) process for PSA air separation nitrogen production. The process is based on axial flow fixed bed pressure swing adsorption (PSA), and multiple axial flow fixed bed adsorption towers are placed in the center of a multi-channel rotary valve and arranged on a circular rotating tray around it. The valves are connected through pipelines and the rotation direction and rotation speed (ω1) of the rotary valve and the rotation direction and rotation speed (ω2) of the circular rotating tray are regulated, so that the gas flowing through the multi-channel rotary valve channel and the pipelines connected to the inlet and outlet ends of the channel and the inlet and outlet ends of the adsorption tower on the circular rotating tray and the rotating and moving adsorption bed in the adsorption tower continuously passes through the position of the inlet and outlet of each adsorption tower. The arrangement and each adsorption bed layer complete the mass transfer of their own adsorption and desorption steps while rotating, thereby forming a "simulated rotating moving bed" pressure swing adsorption process, realizing a simulated rotating moving bed pressure swing adsorption process based on axial flow fixed bed pressure swing adsorption, making the adsorption and desorption of nitrogen production by air separation fast and multi-step cyclic operation, while achieving "double high" yield and purity and avoiding deep adsorption and co-adsorption, it is suitable for the corresponding flow rate, component concentration, pressure or temperature fluctuation conditions of air as raw gas, making full use of the various advantages of axial flow fixed bed pressure swing adsorption, rotating wheel adsorption and simulated moving bed, and overcoming the defects of these existing technical processes. The specific scheme is as follows:

[0007] A full temperature range simulated rotating moving bed pressure swing adsorption (FTrSRMPSA) air separation nitrogen production process, the full temperature range simulated rotating moving bed pressure swing adsorption (FTrSRMPSA) system is composed of n (3≤n≤20 natural integer) axial flow fixed bed adsorption towers loaded with one or more adsorbents and arranged on an annular rotating tray with a rotation speed (ω2, seconds (s) as the unit), a multi-channel rotary valve with m (5≤m≤36 natural integer) channels and arranged in the center of the annular rotating tray and rotating at a rotation speed (ω1, seconds (s) as the unit), and a multi-channel rotary valve. The valve and the material pipeline for the inlet and outlet of the material gas outside the system, and the process pipeline connected to the upper and lower adsorption tower and the multi-channel rotary valve through the built-in pipeline of the annular tray, as well as the corresponding driving mechanism for driving the rotation direction of the annular rotating tray and the multi-channel rotary valve and regulating its rotation speed (ω1 and ω2), the buffer tank, the vacuum pump / or the compressor form an FTrSRMPSA system, characterized in that the pipeline connecting the inlet and outlet of the adsorption tower and the inlet and outlet of the m-channel rotary valve is connected through the built-in pipeline preset in the annular rotating tray to form a process pipeline and has the same number of channels m as the m-channel rotary valve, and the inlet and outlet of the FTrS The position of the material gas in the RMPSA system is fixed by the distribution of the rotating channel of the m-channel rotary valve. The material gas includes air as raw gas (F), N2 product gas (N2PG), flushing gas (P), final charging gas (FR) and desorption gas (D) composed of reverse release (D) gas or / and vacuum air (V) or / and flushing waste gas (PW), and is connected to the corresponding equipment including buffer tank (device), compressor / vacuum pump / circulation pump. The position of the process gas flow in the process pipeline connected between the inlet and outlet of the m-channel rotary valve and the inlet and outlet of the adsorption tower through the built-in pipeline in the circular rotating tray is mobile and variable. The process gas flows in the FTrSRMPSA system, including feed gas (F), N2 product gas (N2PG), flushing gas (P), pressure-equalizing gas (ED), forward venting (PP) and reverse venting (D) gas or / and vacuum air (V) or / and flushing waste gas (PW) composed of desorption gas (D), pressure-equalizing gas (ER) and final filling gas (FR). The specific cycle of air separation nitrogen adsorption and desorption is that the feed gas air (F) from the outside of the FTrSRMPSA system has a temperature of 10~90℃, a pressure of 0.3~2.0MPa, and a flow rate of 100~20,000Nm 3 / h, enters the raw gas (F) inlet of the m-channel rotary valve, and enters from the bottom of the adsorption tower for adsorption (A) through the raw gas (F) channel and outlet of the m-channel rotary valve, the built-in pipeline of the annular rotating tray, and the process pipeline connected to the inlet of one or more axial flow fixed bed adsorption towers in the adsorption state on the corresponding annular rotating tray. After the rotation direction and rotation speed (ω1) of the m-channel rotary valve and the rotation direction and rotation speed (ω2) of the annular rotating tray are regulated and matched continuously, the non-adsorbed phase gas flowing out from the top of the adsorption tower just enters through the process pipeline The N2 product gas (N2PG) enters the N2 product gas (N2PG) channel of the m-channel rotary valve, and flows out from the N2 product gas (N2PG) channel of the m-channel rotary valve into the N2 product gas (N2PG) buffer tank and then is output. The purity of the N2 product gas (N2PG) is 96~99.9%. After the adsorption tower in the adsorption state completes the adsorption (A) step, as the m-channel rotary valve and the annular rotating tray continue to rotate and step, the adsorption tower that ends the adsorption (A) step enters the sequential release (PP) and equal pressure drop (ED) steps. The sequential release gas (PP) flowing out of the sequential release (PP) step is used as the flushing gas ( The liquid flows through the inner pipe of the donut-shaped rotating tray, the forward and backward (PP) channel of the m-channel rotating valve, other inner pipes of the donut-shaped rotating tray and other adsorption towers in the flushing (P) step to flush (P), and the adsorption tower in the forward (PP) step is finished. Then, the other adsorption tower in the equal pressure rise (ER) state is subjected to equal pressure drop (ED) through the process pipe in the system, and the adsorption tower in the equal pressure drop (ED) step is finished. As the m-channel rotating valve and the donut-shaped rotating tray continue to rotate step by step, the liquid enters the reverse release (D) or / and vacuum (V) or / and flushing ( P) step, the desorbed gas (D) formed by the reverse venting gas (D) or / and the vacuum air (V) or / and the flushing waste gas (PW) flowing out of the adsorption tower flows through the internal pipeline of the annular rotating tray and the reverse venting gas (D) / vacuum air (V) / flushing waste gas (PW) channel of the m-channel rotary valve and the desorbed gas (D) formed by the outlet end thereof enters the desorbed gas (D) buffer tank, and a part of it is purified by temperature swing adsorption (TSA) and the circulating gas (CG) formed by the circulating pump and pressurization is returned to the air raw gas (F) for recycling, and the obtained purity is 96~99.9% N2 product gas (N2PG) yield is greater than or equal to 60-70%, a part of which is either directly discharged or enters the oxygen-enriched extraction system, and the adsorption tower in the inversion (D) or / and vacuum (V) or / and flushing (P) step is completed. As the m-channel rotary valve and the annular rotary tray continuously rotate and step, it enters the equalization pressure increase (ER) and / or waiting (-) step, flows out from the adsorption tower in the equalization pressure drop (ED) step and enters the adsorption tower in the equalization pressure increase (ER) step through the built-in pipeline of the annular rotary tray and the equalization pressure drop gas (ED) channel of the m-channel rotary valve for equalization of pressure, so that the pressure in the adsorption tower in the equalization pressure increase (ER) step is equal to the pressure in the adsorption tower in the equalization pressure drop (ED) step. The adsorption tower that has finished the equalizing pressure rise (ER) and / or the waiting area (-) step enters the final filling (FR) step as the m-channel rotary valve and the annular rotating tray continue to rotate. The final filling gas (FR) from outside the system flows through the final filling gas (FR) channel of the m-channel rotary valve and the built-in pipeline of the annular rotating tray to enter the adsorption tower for pressurization until the pressure in the adsorption tower reaches the adsorption pressure required for the adsorption (A) step. That is, the operation of the adsorption tower has undergone an adsorption and desorption cycle consisting of adsorption (A)-forward release (PP) / equalizing pressure drop (ED)-reverse release (D) / vacuuming (V)-flushing (P)-equalizing pressure rise (ER) / waiting (-)-final filling (FR) steps, and is ready for the next round of adsorption and desorption cycles. Operation, wherein each adsorption tower performs one step or multiple steps and each step is performed by regulating and matching the rotation direction and rotation speed (ω1) of the rotary valve with the rotation direction and rotation speed (ω2) of the annular rotating tray, so that the timing table of the cyclic operation of adsorption and desorption of the m channels in the rotating m-channel rotary valve and the n adsorption towers in the rotating annular rotating tray is connected end to end into a circle, and the operational cyclicity of the pressure swing adsorption (PSA) adsorption and desorption process is completely formed, all the material gases and process gases are evenly and alternately distributed in the m circular channels in the m-channel rotary valve in the system and the built-in pipelines in the annular rotating tray and each adsorption tower, and a cycle of pressure swing adsorption (PSA) is completed. Through the rotating rotary valve (ω1) and the corresponding rotating annular rotating tray (ω2), the adsorption towers simultaneously carry out various steps in the adsorption and desorption process. The position of the process gas entering and leaving the adsorption tower is constantly changed by matching the rotation direction and rotation speed (ω1) of the rotary valve with the rotation direction and rotation speed (ω2) of the annular rotating tray, so that each adsorption tower repeats the adsorption and desorption steps, which is equivalent to each fixed bed adsorption tower completing its own adsorption and desorption steps while the m-channel rotary valve and the annular rotating tray rotate, thereby forming a "simulated rotating moving bed" pressure swing adsorption process, thereby obtaining the product N2 from the air with a purity of 96~99.9% and a yield greater than or equal to 50~70%. .

[0008] Furthermore, the air separation nitrogen production process of the full temperature range simulated rotating moving bed pressure swing adsorption (FTrSRMPSA) is characterized in that the rotation direction of the m-channel rotary valve and the annular rotating tray and the regulation and matching of their rotation speeds (ω1 and ω2) include: 1) synchronous in the same direction, rotating in the same direction in a clockwise or counterclockwise direction, and ω1=ω2 / ≠0, 2) asynchronous in the same direction, rotating in the same direction in a clockwise or counterclockwise direction, and ω1>ω2 or ω1<ω2 or ω1≠0 / ω2=0 or ω1=0 / ω2 ≠0, 3) heterodyne synchronization, clockwise / counterclockwise or counterclockwise / clockwise heterodyne rotation, and ω1=ω2 / ≠0, 4) heterodyne asynchrony, clockwise / counterclockwise or counterclockwise / clockwise heterodyne rotation, and ω1>ω2 or ω1<ω2 or ω1≠0 / ω2=0 or ω1=0 / ω2≠0, preferably, unidirectional synchronization, unidirectional rotation in clockwise or counterclockwise direction, and ω1=ω2 / ≠0, and unidirectional asynchrony, clockwise or counterclockwise rotation in the same direction, and ω1≠0 / ω2=0, or ω1=0 / ω2≠0.

[0009] Furthermore, the air separation nitrogen production process of the full temperature range simulated rotating moving bed pressure swing adsorption (FTrSRMPSA) is characterized in that the adsorbent loaded in the n axial flow fixed bed adsorption towers is a carbon molecular sieve (CMSN2) of large and small pore sizes mixed in proportion and / or a plurality of combinations mixed in proportion with 5A molecular sieve and 13X, preferably, a plurality of combinations of carbon molecular sieves (CMSN2) of large and small pore sizes mixed in proportion with 5A molecular sieve and 13X.

[0010] Furthermore, the air separation nitrogen production process of the full-temperature range simulated rotating moving bed pressure swing adsorption (FTrSRMPSA) is characterized in that the average pressure drop (ED) and the average pressure rise (ER) have a maximum number of 2 and a minimum number of 1, and the adsorption operating pressure is greater than or equal to 0.6 MPa.

[0011] Furthermore, the air separation nitrogen production process of the full temperature range simulated rotating moving bed pressure swing adsorption (FTrSRMPSA) is characterized in that the flushing gas (P), or the vented gas (PP) flowing out from the venting (PP) step in the system, or the N2 product gas (N2PG) outside the system, or the desorbed gas (D) formed by the vacuum air (V) and the flushing waste gas (PW) in the later stage of the vacuum pumping (V) step, is purified by temperature swing adsorption (TSA) and passed through a circulating pump and pressurized to form a circulating gas (CG), which is flushed in batches through one or more openings in the channel (channel) of the m-channel rotary valve, and the number of openings is at most 3. Preferably, the N2 product gas (N2PG) is the flushing gas (P), ensuring that the purity of the N2 product gas (N2PG) is greater than or equal to 99%, or, preferably, the vented gas (PP) from the venting (PP) step is the flushing gas (P), ensuring that the yield of the N2 product gas (N2PG) is greater than or equal to 65%.

[0012] Furthermore, the air separation nitrogen production process of the full-temperature range simulated rotating moving bed pressure swing adsorption (FTrSRMPSA) is characterized in that the inversion (D) step adopts a vacuum method for desorption, and the additional vacuum pump is either connected to the logistics pipeline of the desorbed gas (D) flowing out of the m-channel rotary valve, or directly connected to the external pipeline connected to the outlet end of the adsorption tower on the annular rotating tray and a control valve is provided on the external pipeline, preferably directly connected to the external pipeline connected to the outlet end of the adsorption tower on the annular rotating tray and a control valve is provided on the external pipeline.

[0013] Furthermore, the air separation nitrogen production process of the full-temperature simulated rotating moving bed pressure swing adsorption (FTrSRMPSA) is characterized in that the final charge (FR) is either the air raw material (F) from outside the system, or the N2 product gas (N2PG), or the desorbed gas (D) formed by the vacuum air (V) and the flushing waste gas (PW) in the later stage of the vacuum pumping (V) step, which is purified by temperature swing adsorption (TSA) and passed through a circulating pump and pressurized to form a circulating gas (CG). Under the condition that the purity of the N2 product gas (N2PG) is greater than or equal to 99%, the N2 product gas (N2PG) is preferably used as the final charge (FR).

[0014] Furthermore, the air separation nitrogen production process of the full-temperature simulated rotating moving bed pressure swing adsorption (FTrSRMPSA) is characterized in that the N2 product gas (N2PG) with a purity of 99.9% is hydrogenated and deoxygenated by a palladium-based catalyst and / or deoxygenated, dehydrogenated and dried by chemical adsorption of an activated carbon or carbon fiber or carbon nanotube-supported catalyst or a copper catalyst to obtain a high-purity N2 product gas (N2PG) with a purity greater than 99.99% and a dew point less than -40°C.

[0015] Furthermore, the air separation nitrogen production process of the full-temperature simulated rotating moving bed pressure swing adsorption (FTrSRMPSA) is characterized in that the desorbed gas (D) enters the VPSA or VSA air separation oxygen enrichment device directly or by blast pressurization, and produces an oxygen-enriched product gas with a concentration of 85-95%. The nitrogen-enriched desorbed gas produced therefrom is either returned to the raw gas (F) of the FTrSRMPSA air separation nitrogen production system, or is used as a flushing gas (P), or as a final filling gas (FR). The yield of the N2 product gas (N2PG) obtained by this system is greater than or equal to 70%. Preferably, the desorbed gas (D) produced in the early stage of the inversion (D) or / and vacuum pumping (V) step is used as the raw gas for air separation oxygen enrichment.

[0016] The beneficial effects of the present invention are:

[0017] (1) Through the present invention, the adsorption and desorption cycle operation mode of the traditional fixed composite bed PSA can be simulated into a full-temperature rotary wheel moving bed PSA process, thereby obtaining a higher purity and yield of N2 products than the fixed bed or typical fan-shaped adsorption chamber rotary wheel PSA. This breaks through the significant technical limitation of "purity and yield are inversely proportional" in conventional and fixed adsorption bed air separation nitrogen production, and greatly reduces the complexity and cost of rotary wheel PSA process and equipment manufacturing, so that the purity of N2 product gas is 96~99.9%, and the yield is 50~70%.

[0018] (2) The present invention can realize a multi-combination and multi-step adsorption and desorption PSA cycle operation on the traditional fixed bed PSA process by regulating and matching the rotation direction and rotation speed (ω1 and ω2) of the multi-channel rotary valve and the circular rotating tray, thereby solving the limitation problems of low operating pressure and short cycle time of the traditional axial flow and radial flow fixed bed PSA air separation nitrogen production equipment, and strict requirements on the adsorption bed with low resistance drop and uniform air flow distribution, and fast opening and closing and long life valves. It can also be flexibly adjusted according to the technical indicators and operating conditions of the N2 product, and covers the typical axial flow or radial flow fixed bed PSA processes such as pressure swing adsorption (PSA) and vacuum pressure swing adsorption (VPSA), as well as the existing moving bed PSA processes such as the moving bed process of the typical fan-shaped adsorption chamber rotating wheel PSA or fast wheel PSA.

[0019] (3) The present invention significantly reduces the number of program control valves and regulating valves in the traditional fixed-bed PSA air separation nitrogen production device, and can replace the gas flow distributor (plate / disc), which is one of the core components in the air separation nitrogen production equipment, and reduce the adsorbent loading amount, so that the height-to-diameter ratio of the axial flow fixed bed is further reduced. At the same time, it also reduces the complexity of manufacturing radial flow fixed bed PSA and fast wheel PSA devices and can replace foreign imports, further reducing investment and production costs.

[0020] (4) The present invention adapts to large fluctuations in air feed gas, including fluctuations in composition, concentration, pressure, temperature, flow rate, etc., by regulating and matching the rotation direction and rotation speed (ω1 and ω2) of the multi-channel rotary valve and the annular rotating tray. It has greater operational flexibility and does not require the expensive regular adsorbent required by the rotary wheel PSA process. Conventional granular adsorbents can be used to form a composite adsorbent bed.

[0021] (5) The present invention plays a great role in regulating the kinetic adsorption and equilibrium adsorption mechanism of nitrogen production by air separation by adjusting the rotation speed ω1 of the multi-channel rotary valve and the rotation speed ω2 of the annular rotating tray, opening through holes in the annular channels of the multi-channel rotary valve and providing a common channel for process gases, etc., thereby realizing a multi-step and multi-cycle process of adsorption and desorption, thereby improving the production capacity of a unit adsorbent or a single adsorption tower, and breaking the defect of the number of channels being limited in the manufacturing process of conventional multi-channel rotary valves, further improving the mass transfer efficiency and production scale, and obtaining a "double-high" N2 product with high purity and high yield.

[0022] (6) The present invention adjusts and designs the height-to-diameter ratio of the adsorption tower by adjusting the rotation direction of the multi-channel rotary valve and the annular rotating tray and the matching of the rotation speeds ω1 and ω2 as well as the adsorption pressure and temperature according to the requirements of the air raw material and its fluctuating working conditions and the technical indicators of the product N2, so that the radial diffusion in the axial flow fixed bed is negligible and the mature mass transfer model of the axial flow fixed bed is satisfied. The influence of the axial flow diffusion becomes smaller and smaller as ω2 increases and the height-to-diameter ratio decreases, thereby making the mass transfer process in the adsorption tower closer to the "steady-state" effect of a moving bed represented by a circulating bed, and the purity and yield of the N2 product are closer to the "double high" of the theoretical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the process of Example 1 of the present invention.

[0024] Figure 2 This is a schematic diagram of the process of Example 2 of the present invention.

[0025] Figure 3 This is a schematic diagram of the process of Example 3 of the present invention.

[0026] Figure 4 This is a schematic diagram of the process of Example 4 of the present invention. DETAILED DESCRIPTION

[0027] In order to enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention.

[0028] Example 1

[0029] like Figure 1As shown, a full temperature range simulated rotating moving bed pressure swing adsorption (FTrSRMPSA) air separation nitrogen production process, wherein the full temperature range simulated rotating moving bed pressure swing adsorption (FTrSRMPSA) system is composed of four axial flow fixed bed adsorption towers with a height-to-diameter ratio of 2, which are loaded with a combination of a plurality of adsorbents composed of a large and small pore carbon molecular sieve (CMSN2) in a ratio of 0.2:0.8 and a carbon molecular sieve (CMSN2):13X / 5A molecular sieve in a ratio of 1:0.5, and are placed on an annular rotating tray with a rotation speed of ω2 = 50~160s. The adsorption tower (n=4) and the corresponding driving mechanism, and a rotating tray with m channels (m=7) and a rotating tray with a rotation speed of ω1 =50~160s 7-channel rotary valve, air raw gas (F) booster 1, heat exchanger 1 / 2, cooler, TSA purification device, 7-channel rotary valve and material gas inlet and outlet pipeline composed of air raw gas (F), N2 product gas (N2PG), desorption gas (D), flushing waste gas (PW) and final charging gas (FR), and process pipeline connected to the upper and lower adsorption towers and the 7-channel rotary valve through the built-in pipeline of the circular rotating tray, and the buffer tank of raw gas (F) N2 product gas (N2PG) / desorption gas (D) are respectively connected to the heat exchanger 1 / 2 and desorption gas (D) cooler, and the outlet of the 7-channel rotary valve flushing waste gas (PW) channel is connected to a temperature swing adsorption (TSA) purification device and a purified gas booster 2 and a material pipeline connected to the outlet of the booster 2 and the inlet and outlet of the heat exchanger 2 and the inlet of the 7-channel rotary valve final charging (FR) channel to form a FTrSRMPSA system, wherein the rotation speed ω1 of the 7-channel rotary valve is 50~160s, the rotation speed ω2 of the annular rotating tray is 50~160s, and the allocation mode between the two is synchronous in the same direction, that is, the rotation direction The same is counterclockwise and the rotation speed is equal, ω1=ω2=50~160s. The functions of the 7 channels in the 7-channel rotary valve are as follows: 1 channel supplies air raw gas (F), 1 channel supplies nitrogen (N2) product gas (N2PG), 1 channel is used as a common supply of forward venting (PP) and flushing gas (P), 1 channel is used as a common supply of pressure-equalizing gas (ED) and pressure-equalizing gas (ER), 1 channel supplies reverse venting (D) as desorption gas (D), 1 channel supplies flushing waste gas (PW), and 1 channel is used for final inflation (FR). The reverse vent gas (D) flowing out of the rotary valve outlet is the desorption gas (D) and the N2 product gas (N2PG) material pipeline is connected to the N2 product gas (N2PG) and desorption gas (D) buffer tanks respectively, and the flushing waste gas (PW) material pipeline is connected to the inlet gas end of a temperature swing adsorption (TSA) purification device. The purified gas flowing out of the purification device is pressurized by the booster 2 and heated by the heat exchanger 2, and then connected to the inlet end of the final charging (FR) channel of the 7-channel rotary valve as the final charging (FR). The specific process is that the raw gas is ambient air, which is pressurized to 0.3~0.4MPa and after being heated to 60~80℃ in heat exchanger 1 through raw gas (F) buffer tank and regeneration gas from TSA purification device, it enters the raw gas (F) channel of rotary valve (if m=1) through raw gas (F) material pipeline connected to 7-channel rotary valve channel and enters adsorption tower 1 through the outlet of the channel through hole connected to the built-in pipeline of the annular rotary tray and the process pipeline formed by the inlet end of adsorption tower 1 and performs adsorption (A) step, wherein nitrogen (N2) and trace amount of argon (Ar) in the air are used as non-adsorbed phase gases and flow out from the outlet end of adsorption tower 1 as N2 product gas (N2PG) and pass through the process pipeline connected to adsorption tower 1. , the process pipeline composed of the built-in pipeline of the annular rotating tray and the through hole of the N2 product gas (N2PG) channel (such as m=2) of the 7-channel rotary valve, the nitrogen (N2) purity of 96~99.9% (v / v) N2 product gas (N2PG) flows out from the N2 product gas (N2PG) material pipeline connected to the 7-channel rotary valve and the heat exchanger 2 (cooling) and the N2 product gas (N2PG) buffer tank, and enters the N2 product gas (N2PG) buffer tank or directly transports it to the outside. The adsorbent in the adsorption tower 1 adsorbs oxygen (O2) in the air, and micro-balances argon (Ar), a small amount of water (H2O), carbon dioxide (CO2), hydrocarbons (C. n H m ) and residual nitrogen (N2), after the adsorption (A) step of adsorption tower 1 is completed, as the 7-channel rotary valve and the annular rotating tray rotate synchronously in the counterclockwise direction, the steps are as follows: Figure 1 At the initial position of adsorption tower 2, adsorption tower 1 enters the release (PP) and pressure drop (ED) steps of the desorption process. At the same time, adsorption tower 2 sequentially steps to the following steps: Figure 1 The initial position of the adsorption tower 3, the adsorption tower 3 is sequentially stepped to Figure 1 The initial position of the adsorption tower 4 is sequentially stepped to the following positions: Figure 1In the initial position of the adsorption tower 1, the process gas generated by the sequential release (PP) of the adsorption tower 1 flows through the built-in pipeline connecting the annular rotating tray, the process pipeline of the 7-channel rotary valve and the common channel of the rotary valve (such as m=3) and is used as the flushing gas (P) to vacuum flush (P) the adsorption tower 3 in the flushing (P) step. As the 7-channel rotary valve and the annular rotating tray continue to rotate synchronously in the same direction, the adsorption tower 1 that has completed the sequential release (PP) step enters the equalizing pressure drop (ED) step. The generated equalizing pressure drop (ED) process gas flows through the built-in pipeline connecting the annular rotating tray, the process pipeline of the 7-channel rotary valve and the common channel of the 7-channel rotary valve equalizing pressure drop (ED) / equalizing pressure rise (ER) to equalize the pressure with the adsorption tower 4 in the equalizing pressure rise (ER) step, so that the pressure of the adsorption tower 1 is equal to that of the adsorption tower 4, which is 0.15~0.2MPa. The adsorption tower 1 that has completed the equalizing pressure drop (ED) step, as the 7-channel rotary valve and the annular rotating tray continue to rotate synchronously in the same direction to as shown in FIG. Figure 1 The initial position of the middle adsorption tower 3 enters the inversion (D) and flushing (P) steps in turn. At the same time, the other three adsorption towers also rotate synchronously in the same direction and step to their respective new positions in turn. The reversed discharge gas (D) generated by the inversion (D) of the adsorption tower 1 is the desorption gas (D) process gas. It flows through the built-in pipeline connecting the circular rotating tray and the 7-channel rotary valve process pipeline and the 7-channel rotary valve reverse discharge gas (D) channel (such as m=5) and the material pipeline connected to the desorption gas (D) cooler at the outlet end, and is cooled to the ambient temperature and enters the desorption gas (D) buffer tank for output or discharge. The adsorption tower 1 that ends the inversion (D) step is discharged along with the 7-channel rotary valve and the circular rotating tray. The disks continue to rotate synchronously in the same direction and enter the flushing (P) step. The venting gas (PP) from the adsorption tower 4 in the venting (PP) step is used as the flushing gas (P) and flows through the inner pipe of the annular rotating tray, the process pipe of the 7-channel rotary valve, and the common channel of the venting gas (PP) / flushing gas (P) of the 7-channel rotary valve (e.g., m=3) to enter the adsorption tower 1 for flushing (P). The flushing waste gas (PW) generated flows through the inner pipe of the annular rotating tray, the process pipe of the 7-channel rotary valve, and the flushing waste gas (PW) channel of the 7-channel rotary valve (e.g., m=6) and enters the TSA purification device for purification to remove CO2, water and hydrocarbons (C n H m ) and other impurities, the generated purified gas (PG) is pressurized to 0.3~0.4MPa by the supercharger and heated by the heat exchanger 2 as the final charge (FR). As the 7-channel rotary valve and the annular rotating tray continue to rotate synchronously in the same direction, they step to the following Figure 1The initial position of the middle adsorption tower 4 enters the equalizing pressure rise (ER) and final filling (FR) steps in turn. At the same time, the other three adsorption towers also rotate synchronously in the same direction and step to their respective new positions in turn. At this time, the equalizing pressure reduction gas (ED) flowing out of the adsorption tower 3 in the equalizing pressure drop (ED) step flows through the built-in pipeline of the annular rotating tray and the process pipeline of the 7-channel rotary valve and the common channel (such as m=4) of the 7-channel rotary valve equalizing pressure drop (ED) / equalizing pressure rise (ER) to equalize the pressure, so that the pressure of the adsorption tower 1 is increased from normal pressure to the same pressure as the adsorption tower 3 in the equalizing pressure drop (ED) step. The pressure of the adsorption tower 1 is equal to 0.15~0.2MPa. The adsorption tower 1 that has finished the equalization pressure rise (ER) step enters the final filling (FR) step as the 7-channel rotary valve and the annular rotating tray continue to rotate synchronously in the same direction. The purified gas (PG) heated to 60~80℃ and the pressure of 0.3~0.4MPa by the heat exchanger 2 is used as the final filling (FR). It flows through the 7-channel rotary valve final filling (FR) channel (such as m=7), the rotary valve process pipeline, the annular rotating tray built-in pipeline and the adsorption tower 1 inlet end into the adsorption tower 1 for final filling ( The pressure in the adsorption tower 1 reaches the pressure of 0.3~0.4MPa required for the adsorption (A) step, thereby forming a complete and multi-step pressure swing adsorption (PSA) closed-loop cycle operation of the adsorption tower 1, that is, adsorption (A)-forward discharge (PP) / equal pressure drop (ED)-reverse discharge (D) / flushing (P)-equal pressure increase (ER) / final filling (FR) steps, and then the adsorption tower 1 enters the next adsorption and desorption closed-loop cycle operation process, and the corresponding material gas and process gas entering and leaving the adsorption towers 2, 3 and 4 are also adsorbed and desorbed in the adsorption tower 1. During the closed-loop cycle operation of desorption, the circular rotating tray and the 7-channel rotary valve continuously rotate to match and alternately switch the material or / and process gas inlet and outlet positions of each adsorption tower to perform corresponding closed-loop cycle operation steps of adsorption and desorption. The closed-loop cycle operation steps of each adsorption tower correspond to the closed-loop cycle operation steps of the other three adsorption towers. Thus, nitrogen (N2) product gas (N2PG) with a purity of 96~99.9% (v / v) and a product gas yield of 50~70% is continuously produced from ambient air as raw material gas. In this case, the higher purity of N2 in the downstream purge gas (PP) is used to replace the N2 product gas (N2PG) as the flushing gas (P), thereby improving the product gas yield. At the same time, the flushing waste gas (PW) that has been purified by TSA is recycled as the final charging gas (FR), reducing the emission of the flushing waste gas (PW) as the desorption gas (D). It can also avoid the problem that the accumulation of impurity components caused by the use of air raw gas (F) as the final charging gas (FR) affects the purity of the product gas, or the product gas is used as the final charging gas (FR). The problem of reduced product gas production or reduced yield is achieved by the simulated rotating PSA process based on the axial flow fixed bed in the air to nitrogen PSA process. The "double highs" of high purity and high yield are achieved.Compared with the classic axial flow fixed bed BF-PSA air separation nitrogen production process, the purity and yield of the N2 product obtained in this Example 1 are relatively high, especially the yield is 20% higher.

[0030] Example 2

[0031] like Figure 2As shown, on the basis of Example 1, the rotation direction of the 7-channel rotary valve and the annular rotating tray in the FTrSRMPSA system and the regulation matching mode between the rotation direction and the regulation of their rotation speed (ω1 and ω2) are adjusted to be synchronous and asynchronous, that is, the rotation direction of the 7-channel rotary valve is counterclockwise, and its rotation speed is adjusted from ω1=50~160s in Example 1 to ω1=30~60s, and the rotation speed of the annular rotating tray is adjusted to ω2=0, that is, it does not rotate, and an external pipeline is set between the stationary annular rotating tray and the adsorption tower to connect the vacuum pump and the vacuum air (V) as the desorption gas (D) material pipeline and the desorption gas (D) buffer tank to form the FTrSRMPSA system of this case, that is, in the FTrSRMPSA system in Example 1, the closed-loop cycle operation of adsorption and desorption of pressure swing adsorption performed by each adsorption tower - adsorption (A)-forward release (PP) / equal pressure drop (ED)-reverse release (D) / rush In the washing (P)-equalizing pressure increase (ER) / final filling (FR) steps, in the FTrSRMPSA system of this embodiment, a vacuum (V) desorption step is used to replace the reverse discharge (D) step in Example 1, and the vacuum degree is -0.08MPa, and the flushing (P) step is also called vacuum flushing (VP), and the reverse discharge (D) channel (such as m=5) of the 7-channel rotary valve is an empty channel, corresponding to the vacuum air (V) as the desorption gas (D) flowing through the external pipeline and the material pipeline and entering the desorption gas (D) buffer tank. Therefore, in this embodiment, only the faster rotation speed of the 7-channel rotary valve itself is relied on to alternately switch the material and process gas into each adsorption tower and perform a complete and multi-step pressure swing adsorption (PSA) closed-loop cycle operation, that is, adsorption (A)-forward discharge (PP) / equalizing pressure drop (ED)-vacuum (V) / vacuum flushing (VP)-equalizing pressure increase (ER) / final filling (FR) steps, and the annular rotating tray is stationary.In this embodiment, all the material gases and process gases are evenly and alternately distributed in the 7 circular channels of the 7-channel rotary valve in the system and the internal pipes, external pipes and various adsorption towers in the annular rotating tray, and a cycle of pressure swing adsorption (PSA) is carried out simultaneously through the rotating 7-channel rotary valve (ω1) and the 4 adsorption towers on the corresponding stationary annular rotating tray (ω2=0). The position of the process gas entering and leaving each adsorption tower is continuously changed by the rotation direction and rotation speed (ω1) of the 7-channel rotary valve. Each adsorption tower repeats the adsorption and desorption steps, which is equivalent to each fixed-bed adsorption tower completing its own adsorption and desorption steps without rotating as the 7-channel rotary valve rotates, thereby forming a "simulated rotating moving bed" pressure swing adsorption process, that is, PSA4-1-1V / P operation mode. Among the four towers, one adsorption tower is always in the adsorption step, and the pressure is equalized once, and vacuum desorption / vacuum flushing is performed. As a result, the nitrogen (N2) product gas (N2PG) obtained from the ambient air has a purity of 98~99.9% (v / v), and the product gas yield is 50~70%.

[0032] Compared with Example 1, this embodiment uses vacuum (V) desorption and vacuum flushing (VP) steps to replace the inversion (D) atmospheric desorption and atmospheric flushing (P) steps in Example 1, and by adjusting the rotation speed of the 7-channel rotary valve to ω1=30~60s to correspond to the closed cycle operation process of adsorption and desorption of the stationary annular rotating tray and its four adsorption towers, high-purity and high-yield nitrogen (N2) product gas (N2PG) can also be obtained.

[0033] Example 3

[0034] like Figure 3As shown, on the basis of Example 1 or / and 2, the N2 product gas (N2PG) with a purity of 99.0-99.9% (v / v) obtained from the FTrSRMPSA system and not cooled by the heat exchanger 2 is directly transported to a deoxidation device filled with a palladium metal catalyst, and 99.99-99.999% hydrogen (H2) is introduced at the same time, and catalytic deoxidation is carried out at a reaction temperature of 70-80°C and a reaction pressure of 0.3-0.4MPa, so that the trace amount of oxygen in the N2 product gas (N2PG) reacts with the hydrogen introduced to achieve The N2 product gas (N2PG) is deoxidized, and the oxygen concentration in the obtained N2 product gas (N2PG) is less than 1ppmv, but the residual hydrogen content in the nitrogen is about 0.1%~1%, and the gas dew point will be lower than 0℃, so it can be directly used as nitrogen protective gas. Alternatively, the N2 with an oxygen concentration of less than 1ppmv, a residual hydrogen content of about 0.1%~1% and a dew point below 0℃ is then passed into a dryer with a copper active component adsorbent loaded on a carbon fiber (CNFs) or carbon nanotube (CNTs) substrate, so that the purity of N2 is greater than or equal to 99.99% and the dew point is less than -40℃.

[0035] Example 4

[0036] like Figure 4 As shown, on the basis of Example 1 or / and 2, the reverse vent gas (D) is used as the atmospheric pressure desorption gas (D) or the vacuum air (V) is used as the desorption gas (D) and is directly transported by a delivery pump into a atmospheric pressure adsorption (VSA) air separation oxygen enrichment device consisting of 3 towers, and an oxygen-enriched product gas with an oxygen concentration of 85-95% is produced from the device, and a nitrogen-enriched gas with a concentration greater than or equal to 70-85% is produced as a by-product from the device, or is returned to the air raw gas (F), or is used as the final charge (FR) after being pressurized, or is used as the secondary flushing gas (P2) The secondary flushing waste gas (PW2) generated is treated by the TSA purification device to form a purified gas (PG), which is then pressurized by the booster 2 and heat exchanged by the heat exchanger 2 and then used as the final charge (FR). At this time, the primary flushing waste gas (PW1) generated by the forward venting gas (PP) as the primary flushing gas (P) is directly returned as the raw gas (F). Therefore, the yield of the N2 product gas (N2PG) obtained from the FTrSRMPSA air separation nitrogen production system in this case is greater than or equal to 70%, and oxygen-rich product gas is also produced as a by-product.

[0037] Obviously, the above-described embodiments are only a part of the embodiments of the present invention, but not all of them. Based on the embodiments recorded in the present invention, all other embodiments obtained by those skilled in the art without creative work, or structural changes made under the enlightenment of the present invention, all of which have the same or similar technical solutions as the present invention, fall within the protection scope of the present invention.

Claims

1. A full temperature range simulated rotating moving bed pressure swing adsorption (FTrSRMPSA) air separation nitrogen production process, the full temperature range simulated rotating moving bed pressure swing adsorption system, denoted as "FTrSRMPSA" system, is composed of n axial flow fixed bed adsorption towers loaded with one or more adsorbents and denoted as "n", which are natural integers of 3 to 20 and are placed on an annular rotating tray with a rotation speed denoted as "ω2" and a unit of "seconds / cycle", a multi-channel rotary valve with m channels denoted as "m" and arranged in the center of the annular rotating tray and rotating at a rotation speed denoted as "ω1" and a unit of "seconds / cycle", a material pipeline for the multi-channel rotary valve and material gas outside the system to enter and exit, and a process pipeline connected to the upper and lower adsorption towers and the multi-channel rotary valve through the built-in pipeline of the annular tray, and a corresponding driving mechanism for driving the rotation direction of the annular rotating tray and the multi-channel rotary valve and regulating its rotation speed ω1 and ω2, a buffer tank, and a vacuum pump or compressor to form a FTrSRMPSA system, characterized in that The pipeline connecting the inlet and outlet of the adsorption tower and the inlet and outlet of the m-channel rotary valve is connected through the built-in pipeline preset in the circular rotating tray to form a process pipeline and has the same number of channels m as the m-channel rotary valve. The position of the material gas entering and exiting the FTrSRMPSA system is fixed by the distribution of the rotating channel of the m-channel rotary valve. The material gas includes air as the raw gas denoted as "F", N2 product gas denoted as "N2PG", flushing gas denoted as "P", final charging gas denoted as "FR" and final charging gas denoted as "D D The desorption gas denoted as "D" is composed of the reverse venting gas denoted as "V" or / and the vacuum air denoted as "V" or / and the flushing waste gas denoted as "PW", and the equipment including the buffer tank, the compressor or the vacuum pump or the circulating pump is connected accordingly. The position of the process gas flow in the process pipeline connected between the inlet and outlet of the m-channel rotary valve and the inlet and outlet of the adsorption tower through the built-in pipeline in the circular rotating tray is mobile and changeable. The process gas flows in the FTrSRMPSA system, including the raw gas F, the N2 product gas N2PG, the flushing gas P, the pressure-equalizing gas denoted as "ED", the forward venting gas denoted as "PP", and the reverse venting gas D D or / with the vacuum air V or / with the flushing waste gas PW to form the desorption gas D, the equalized pressure rising gas recorded as "ER" and the final charging gas FR. The specific cycle of air separation nitrogen adsorption and desorption is that the raw gas air F from the outside of the FTrSRMPSA system has a temperature of 10-90℃, a pressure of 0.3-2.0MPa, and a flow rate of 100-20,000Nm 3 / h, enters the raw gas F inlet of the m-channel rotary valve, and passes through the raw gas F channel and outlet of the m-channel rotary valve, the built-in pipeline of the annular rotating tray and the process pipeline connected to the inlet of one or more axial flow fixed bed adsorption towers in the adsorption state on the corresponding annular rotating tray, and enters from the bottom of the adsorption tower to perform the adsorption step marked as "A". After the rotation direction and rotation speed ω1 of the m-channel rotary valve are regulated and matched with the rotation direction and rotation speed ω2 of the annular rotating tray, the non-adsorbed phase gas flowing out from the top of the adsorption tower just enters the N2 product gas N2PG channel of the m-channel rotary valve through the process pipeline, and flows out from the N2 product gas N2PG channel of the m-channel rotary valve into the N2 product gas N2PG buffer tank and then is output. The purity of the N2 product gas N2PG is 96 ~99.9%, after the adsorption tower in the adsorption state completes the adsorption step A, as the m-channel rotary valve and the annular rotating tray continue to rotate and step, the adsorption tower that ends the adsorption step A enters the forward release and equal pressure drop step, and the forward release gas PP flowing out of the forward release step flows as the flushing gas P through the built-in pipeline of the annular rotating tray, the forward release channel of the m-channel rotary valve, other built-in pipelines of the annular rotating tray and other adsorption towers in the flushing step to flush, and then the adsorption tower that ends the forward release step, and then another adsorption tower in the equal pressure rise state is subjected to equal pressure drop through the process pipeline in the system, and the adsorption tower that ends the equal pressure drop step enters the reverse release or / and vacuumization or / and flushing step as the m-channel rotary valve and the annular rotating tray continue to rotate and step, and the reverse release gas D flowing out of the adsorption tower D Or / with the vacuum air V or / with the flushing waste gas PW to form the desorbed gas D, flows through the built-in pipeline of the annular rotating tray and the reverse release gas D of the m-channel rotary valve D / Evacuate air V / flush the waste gas PW channel and the desorbed gas D formed by the outlet end flows into the desorbed gas buffer tank, a part of which is purified by temperature swing adsorption marked as "TSA" and then passed through a circulating pump and pressurized to form a circulating gas marked as "CG" and returns to the air raw gas F for recycling, and the obtained N2 product gas N2PG with a purity of 96-99.9% has a yield greater than or equal to 60-70%, and a part of it is either directly discharged or enters the oxygen-enriched extraction system, ending the adsorption tower of the inversion or / and vacuuming or / and flushing steps, and as the m-channel rotary valve and the annular rotating tray continuously rotate and step, it enters the equalizing pressure rising or / and waiting step marked as "-", from the equalizing pressure dropping step The gas flows out of the adsorption tower and enters the adsorption tower in the pressure-raising step through the built-in pipeline of the annular rotating tray and the pressure-equalizing gas ED channel of the m-channel rotary valve for pressure equalization, so that the pressure in the adsorption tower in the pressure-equalizing step is equal to the pressure in the adsorption tower in the pressure-equalizing step, and the pressure-equalizing or / and waiting-area step of the adsorption tower are terminated. As the m-channel rotary valve and the annular rotating tray further rotate continuously, the final charging step is entered. The final charging gas FR from outside the system flows through the final charging gas FR channel of the m-channel rotary valve and the built-in pipeline of the annular rotating tray to enter the adsorption tower for pressure charging until the pressure in the adsorption tower reaches the adsorption pressure required for the adsorption step A, and prepares for the next round of adsorption and desorption cycle operation. The operation is performed in such a way that each adsorption tower performs one step or multiple steps and each step is performed by matching the rotation direction and rotation speed ω1 of the rotary valve with the rotation direction and rotation speed ω2 of the annular rotating tray, so that the timing table of the cyclic operation of adsorption and desorption of the m channels in the rotating m-channel rotary valve and the n adsorption towers in the rotating annular rotating tray is connected end to end into a circle, and the operational cyclicity of the adsorption and desorption process of the pressure swing adsorption is completely formed, and all the material gases and process gases are evenly and alternately distributed in the m circular channels in the m-channel rotary valve in the system and the built-in pipes in the annular rotating tray and each adsorption tower, and the pressure swing adsorption of a cycle is completed. The adsorption towers attached to the rotating rotary valve and the corresponding rotating annular rotating tray respectively carry out various steps of the adsorption and desorption process simultaneously. The position of the process gas entering and exiting the adsorption tower is constantly changed by matching the rotation direction and rotation speed ω1 of the rotary valve with the rotation direction and rotation speed ω2 of the annular rotating tray, so that each adsorption tower repeats the adsorption and desorption steps, which is equivalent to each fixed bed adsorption tower completing its own adsorption and desorption steps while the m-channel rotary valve and the annular rotating tray rotate, thereby forming a "simulated rotating moving bed" pressure swing adsorption process, thereby, the product N2 obtained from the air has a purity of 96-99.9% and a yield of 50-70%.

2. The air separation nitrogen production process of full temperature range simulated rotating moving bed pressure swing adsorption (FTrSRMPSA) according to claim 1, characterized in that: The rotation direction of the m-channel rotary valve and the annular rotating tray and the regulation and matching between their rotation speeds ω1 and ω2 include: 1) same-direction synchronization, same-direction rotation in clockwise or counterclockwise direction, ω1 and ω2 are equal, and both ω1 and ω2 are not 0; 2) same-direction asynchronism, same-direction rotation in clockwise or counterclockwise direction, ω1>ω2 or ω1<ω2, and ω1 or ω2 is 0; 3) different-direction synchronization, different-direction rotation, ω1 and ω2 are equal, and both ω1 and ω2 are not 0; 4) different-direction asynchronism, different-direction rotation, and ω1>ω2 or ω1<ω2, and ω1 or ω2 is 0.

3. The air separation nitrogen production process of full temperature range simulated rotating moving bed pressure swing adsorption (FTrSRMPSA) according to claim 1, characterized in that: The adsorbent loaded in the n axial flow fixed bed adsorption towers is a carbon molecular sieve marked as "CMSN2" with different pore sizes, a 5A molecular sieve and a 13X molecular sieve mixed in proportion.

4. The air separation nitrogen production process of full temperature range simulated rotating moving bed pressure swing adsorption (FTrSRMPSA) according to claim 1, characterized in that: The maximum number of the average pressure drop and the average pressure rise is 2, and the minimum number is 1, and the adsorption operation pressure is greater than or equal to 0.6 MPa.

5. The air separation nitrogen production process of full temperature range simulated rotating moving bed pressure swing adsorption (FTrSRMPSA) according to claim 1, characterized in that: The flushing gas P, or the discharged gas PP from the system in the discharged step, or the N2 product gas N2PG from outside the system, or the desorbed gas D formed by the vacuum air V in the late stage of the vacuuming step and the flushing waste gas PW, which is purified by the temperature swing adsorption TSA and passed through the circulating pump and pressurized to form the circulating gas CG, is flushed in batches through one or more openings in the channel of the m-channel rotary valve, and the number of openings is at most 3.

6. The air separation nitrogen production process of full temperature range simulated rotating moving bed pressure swing adsorption (FTrSRMPSA) according to claim 1, characterized in that: The reverse placement step adopts a vacuuming method for desorption, and the additional vacuum pump is either connected to the logistics pipeline of the desorbed gas D outflowing from the m channel rotary valve, or directly connected to the external pipeline connected to the outlet end of the adsorption tower on the annular rotating tray and a control valve is provided on the external pipeline.

7. The air separation nitrogen production process of full temperature range simulated rotating moving bed pressure swing adsorption (FTrSRMPSA) according to claim 1, characterized in that: The final charging gas FR may be air raw material F from outside the system, or N2 product gas N2PG, or desorbed gas D formed by vacuum air V and flushing waste gas PW in the later stage of the vacuuming step, which is purified by temperature swing adsorption TSA and then passed through a circulating pump and pressurized to form circulating gas CG.

8. The air separation nitrogen production process of full temperature range simulated rotating moving bed pressure swing adsorption (FTrSRMPSA) according to claim 1, characterized in that: The N2 product gas N2PG with a purity of 99.9% is hydrogenated and deoxygenated with a palladium-based catalyst, and chemically adsorbed with a carbon nanotube-supported catalyst, a copper catalyst, activated carbon or carbon fiber for deoxidation, dehydrogenation and drying to obtain a high-purity N2 product gas N2PG with a purity greater than 99.99% and a dew point less than -40°C.

9. The air separation nitrogen production process of full temperature range simulated rotating moving bed pressure swing adsorption (FTrSRMPSA) according to claim 1, characterized in that: The desorbed gas D is directly or pressurized into the VPSA or VSA air separation oxygen enrichment device, from which an oxygen-enriched product gas with a concentration of 85-95% is produced. The nitrogen-enriched desorbed gas produced therefrom is either returned to the raw gas F of the FTrSRMPSA air separation nitrogen production system, or used as flushing gas P, or used as final charging gas FR.

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