Pressure swing adsorption method

Abstract

The invention provides a pressure swing adsorption method. Comprising the following steps: circularly operating a plurality of adsorption towers according to an adsorption step, a first pressure-equalizing and pressure-reducing step, a second pressure-equalizing and pressure-reducing step, a clockwise releasing step, a third pressure-equalizing and pressure-reducing step, a reverse releasing step, a washing step, a third pressure-equalizing and pressure-increasing step, a second pressure-equalizing and pressure-increasing step, an isolating step, a first pressure-equalizing and pressure-increasing step and a final increasing step. According to the pressure swing adsorption system controlled by a full-automatic program, on-line full-automatic adjustment of the purity and the flow control of the obtained product gas is realized, the system operation reaches the automation and intelligence level, the loss degree of equipment and corresponding materials in the system is greatly reduced, and the service time of the equipment and the corresponding materials in the system is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of pressure swing adsorption, and in particular to a pressure swing adsorption method. Background Art

[0002] Pressure swing adsorption technology has become the main method for separating hydrogen worldwide. It has been maturely used in the separation and purification of gases such as carbon dioxide, carbon monoxide, nitrogen, oxygen, methane, and the purification of other industrial gases, and has been increasingly widely used.

[0003] However, there are many problems with the existing pressure swing adsorption technology. First, the purity of the product gas can meet the requirements, but the obtained product gas flow rate is very low, that is, the yield is low; second, it is difficult to achieve full automatic and intelligent control during system operation; third, the adsorbent in the adsorption tower has a short service life, that is, after a period of operation, the performance of the adsorbent cannot meet the set requirements, resulting in a decrease in the purity of the product gas. Summary of the invention

[0004] In view of the above-mentioned problems existing in the prior art, the object of the present invention is to provide a pressure swing adsorption method, which enables the purity of the product gas and the control of its flow rate to be achieved through online fully automatic adjustment through a pressure swing adsorption system controlled by a fully automatic program, so that the system operation reaches an automated and intelligent level, greatly reducing the degree of wear of the equipment and corresponding materials in the system and extending the service life of the equipment and corresponding materials in the system.

[0005] The technical solution adopted by the present invention is to provide a pressure swing adsorption method, the pressure swing adsorption method is used in a pressure swing adsorption system, and the pressure swing adsorption system comprises: At least five adsorption towers, a product gas buffer tank V, a raw gas delivery pipeline, a product gas outlet pipeline, a final rise pipeline, a pressure equalizing pipeline, a flushing pipeline, and a venting pipeline. The product gas buffer tank V is connected to the product gas outlet pipeline. The raw gas delivery pipeline, the product gas outlet pipeline, the final rise pipeline, the pressure equalizing pipeline, the flushing pipeline, and the venting pipeline are respectively connected to the multiple adsorption towers in a one-to-one corresponding pipeline manner; The pressure swing adsorption method includes: multiple adsorption towers are cyclically operated according to the adsorption step, the first pressure equalization and pressure reduction step, the second pressure equalization and pressure reduction step, the forward release step, the third pressure equalization and pressure reduction step, the reverse release step, the flushing step, the third pressure equalization and pressure increase step, the second pressure equalization and pressure increase step, the isolation step, the first pressure equalization and pressure increase step, and the final pressure increase step.

[0006] Compared with the prior art, the technical effect achieved by adopting the technical scheme is as follows: multiple adsorption towers are cyclically operated according to the adsorption step, the first equalizing pressure reducing step, the second equalizing pressure reducing step, the forward release step, the third equalizing pressure reducing step, the reverse release step, the flushing step, the third equalizing pressure boosting step, the second equalizing pressure boosting step, the isolation step, the first equalizing pressure boosting step, and the final boosting step. The process design is reasonable and high-purity product gas can be obtained more efficiently.

[0007] In an optional embodiment, the adsorption tower includes an adsorption tower T5A, an adsorption tower T5B, an adsorption tower T5C, an adsorption tower T5D, and an adsorption tower T5E, and the raw gas delivery pipeline, the product gas outlet pipeline, the final rise pipeline, the pressure equalization pipeline, the flushing pipeline, and the venting pipeline are respectively connected to the adsorption tower T5A, the adsorption tower T5B, the adsorption tower T5C, the adsorption tower T5D, and the adsorption tower T5E in a one-to-one corresponding pipeline connection; The specific steps of the pressure swing adsorption method are shown in the following table: Among them, A: adsorption step; ED1: first equalizing and reducing pressure step; E2D: second equalizing and reducing pressure step; PP: forward release step; E3D: third equalizing and reducing pressure step; D: reverse release step; P: flushing step; E3R: third equalizing and increasing pressure step; E2R: second equalizing and increasing pressure step; E1R: first equalizing and increasing pressure step; IS: isolation step; FR: final increase step.

[0008] In an optional embodiment, the adsorption tower T5A and the raw gas delivery pipeline, the product gas outlet pipeline, the venting pipeline, the final rise pipeline, the pressure equalizing pipeline, and the flushing pipeline are respectively provided with program-controlled valves T5A1, T5A2, T5A3, T5A4, T5A5, and T5A6 in one-to-one correspondence; The adsorption tower T5B and the raw gas delivery pipeline, the product gas outlet pipeline, the venting pipeline, the final rise pipeline, the pressure equalization pipeline, and the flushing pipeline are respectively provided with program-controlled valves T5B1, T5B2, T5B3, T5B4, T5B5, and T5B6 in a one-to-one correspondence; The adsorption tower T5C and the raw gas delivery pipeline, the product gas outlet pipeline, the venting pipeline, the final rise pipeline, the pressure equalizing pipeline, and the flushing pipeline are respectively provided with program-controlled valves T5C1, T5C2, T5C3, T5C4, T5C5, and T5C6 in one-to-one correspondence; The adsorption tower T5D and the raw gas delivery pipeline, the product gas outlet pipeline, the venting pipeline, the final rise pipeline, the pressure equalization pipeline, and the flushing pipeline are respectively provided with program-controlled valves T5D1, T5D2, T5D3, T5D4, T5D5, and T5D6 in a one-to-one correspondence; The adsorption tower T5E and the raw gas delivery pipeline, the product gas outlet pipeline, the venting pipeline, the final rise pipeline, the pressure equalization pipeline, and the flushing pipeline are respectively provided with program-controlled valves T5E1, T5E2, T5E3, T5E4, T5E5, and T5E6 in a one-to-one correspondence; The final rise pipeline is also provided with a final rise special valve KV; A regulating valve PV is provided on the product gas outlet pipeline; The flow of gas in the raw gas delivery pipeline and the product gas outlet pipeline is controlled by opening or closing the program-controlled valve and the regulating valve to realize the adsorption step; the flow of gas in the venting pipeline is controlled by opening or closing the program-controlled valve to realize the reverse release step; the flow of gas in the final rise pipeline is controlled by opening or closing the program-controlled valve and the final rise special valve to realize the final rise step; the flow of gas in the pressure equalizing pipeline is controlled by opening or closing the program-controlled valve to realize the first pressure equalizing step, the second pressure equalizing step, the third pressure equalizing step, the third pressure equalizing step, the second pressure equalizing step and the first pressure equalizing step; the flow of gas in the flushing pipeline is controlled by opening or closing the program-controlled valve to realize the forward release step and the flushing step.

[0009] Compared with the prior art, the technical effect achieved by adopting this technical solution is as follows: by setting a program-controlled valve and controlling the opening or closing of the program-controlled valve to ensure the automatic operation of the entire system, the control of product purity and its flow rate is achieved through online fully automatic adjustment, and the pressure swing adsorption method that completes the cyclic operation by program control has a high level of intelligence.

[0010] In an optional embodiment, in the same time period, one and only one of the adsorption tower T5A, the adsorption tower T5B, the adsorption tower T5C, the adsorption tower T5D and the adsorption tower T5E must be in the adsorption step.

[0011] Compared with the prior art, the technical effect achieved by adopting this technical solution is as follows: in the same time period, only one of the five towers must be in the adsorption step, and the process design is reasonable, so that the adsorption tower is always in high-pressure adsorption and low-pressure desorption, to ensure that the adsorption separation process is in a reasonable state.

[0012] In an optional embodiment, the adsorption tower includes an adsorption tower T6A, an adsorption tower T6B, an adsorption tower T6C, an adsorption tower T6D, an adsorption tower T6E and an adsorption tower T6F, and the raw gas delivery pipeline, the product gas outlet pipeline, the final rise pipeline, the pressure equalization pipeline, the flushing pipeline, and the venting pipeline are respectively connected to the adsorption tower T6A, the adsorption tower T6B, the adsorption tower T6C, the adsorption tower T6D, the adsorption tower T6E and the adsorption tower T6F by pipelines corresponding to each other; The specific steps of the pressure swing adsorption method are shown in the following table: Among them, A: adsorption step; ED1: first equalizing and reducing pressure step; E2D: second equalizing and reducing pressure step; PP: forward release step; E3D: third equalizing and reducing pressure step; D: reverse release step; P: flushing step; E3R: third equalizing and increasing pressure step; E2R: second equalizing and increasing pressure step; E1R: first equalizing and increasing pressure step; IS: isolation step; FR: final increase step.

[0013] In an optional embodiment, when any one of the plurality of adsorption towers is in the first pressure equalization and pressure reduction step, one of the remaining adsorption towers must be connected to the pressure equalization pipeline and transport gas, and is in the first pressure equalization and pressure increase step; When any one of the plurality of adsorption towers is in the second pressure equalization and pressure reduction step, one of the remaining adsorption towers must be connected to the pressure equalization pipeline and transport gas, and is in the second pressure equalization and pressure increase step; When any one of the multiple adsorption towers is in the third pressure equalization and pressure reduction step, one of the remaining adsorption towers must be connected to the pressure equalization pipeline and transport gas, and is in the third pressure equalization and pressure increase step.

[0014] Compared with the prior art, the technical effect achieved by adopting this technical solution is as follows: by making the first equalizing pressure reducing step correspond to the first equalizing pressure boosting step, making the second equalizing pressure reducing step correspond to the second equalizing pressure boosting step, and making the third equalizing pressure reducing step correspond to the third equalizing pressure boosting step, the control system is simplified, the operating difficulty is reduced, the process efficiency is improved, and the operating cost is reduced.

[0015] In an optional embodiment, when one of the multiple adsorption towers is in the sequential placement step, one of the remaining adsorption towers must be connected to the flushing pipeline and transport gas, and is in the flushing step.

[0016] Compared with the prior art, the technical effect achieved by adopting this technical solution is as follows: by making the sequential placement step and the flushing step correspond to each other, the control system is simplified, the operating difficulty is reduced, the process efficiency is improved, and the operating cost is reduced.

[0017] In an optional embodiment, when one of the multiple adsorption towers is in the adsorption step, at least one adsorption tower is in the inversion step.

[0018] Compared with the prior art, the technical effect achieved by adopting this technical solution is: by rationally configuring the working time of the adsorption tower, the working efficiency of the entire pressure swing adsorption system is further improved.

[0019] In an optional embodiment, in the adsorption step, the first pressure-equalizing and pressure-reducing step, the second pressure-equalizing and pressure-reducing step, the forward release step, the third pressure-equalizing and pressure-reducing step, the reverse release step, the flushing step, the third pressure-equalizing and pressure-raising step, the second pressure-equalizing and pressure-raising step, the isolation step, the first pressure-equalizing and pressure-raising step, and the final pressure-raising step, the starting pressure, the ending pressure, and the working time required for the corresponding steps are: .

[0020] In an optional embodiment, in the adsorption step, the first pressure-equalizing and pressure-reducing step, the second pressure-equalizing and pressure-reducing step, the forward release step, the third pressure-equalizing and pressure-reducing step, the reverse release step, the flushing step, the third pressure-equalizing and pressure-raising step, the second pressure-equalizing and pressure-raising step, the isolation step, the first pressure-equalizing and pressure-raising step, and the final pressure-raising step, the starting pressure, the ending pressure, and the working time required for the corresponding steps are: .

[0021] Compared with the prior art, the technical effect achieved by adopting this technical solution is as follows: by setting the starting pressure and the ending pressure of each step, the working time required for the corresponding step, and setting the corresponding adsorbent dosage ratio, the purity and flow rate of the product gas are guaranteed.

[0022] The pressure swing adsorption method of the embodiment of the present invention has the following beneficial effects: (1) The entire system is operated automatically by controlling the on / off of the valves. The product purity and flow rate are automatically regulated online. The purity and flow rate of hydrogen (product gas) are guaranteed by setting the starting and ending pressures of each step and the working time required for the corresponding step. (2) By making the first pressure-equalizing and pressure-reducing step correspond to the first pressure-equalizing and pressure-raising step, making the second pressure-equalizing and pressure-reducing step correspond to the second pressure-equalizing and pressure-raising step, making the third pressure-equalizing and pressure-reducing step correspond to the third pressure-equalizing and pressure-raising step, and making the sequential release step correspond to the flushing step, the control system is simplified, the operation difficulty is reduced, the process efficiency is improved, and the operation cost is reduced; (3) The operation of the pressure swing adsorption system has reached an automated and intelligent level, which greatly reduces the wear and tear of the equipment and corresponding materials in the system and extends the service life of the equipment and corresponding materials in the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The process flow chart of the pressure swing adsorption method provided by the embodiment of the present invention is shown.

[0024] Description of reference numerals: 100, raw gas transmission pipeline; 200, product gas outlet pipeline; 300, final rise pipeline; 400, pressure equalizing pipeline; 500, flushing pipeline; 600, venting pipeline. DETAILED DESCRIPTION

[0025] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present invention. It should be noted that relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements. See attached Figure 1As shown, the present invention provides a pressure swing adsorption method, the pressure swing adsorption method is used in a pressure swing adsorption system, and the pressure swing adsorption system includes: At least five adsorption towers, a product gas buffer tank V, a raw gas delivery pipeline 100, a product gas outlet pipeline 200, a final rise pipeline 300, a pressure equalizing pipeline 400, a flushing pipeline 500, and a venting pipeline 600, the product gas buffer tank V is connected to the product gas outlet pipeline 200, and the raw gas delivery pipeline 100, the product gas outlet pipeline 200, the final rise pipeline 300, the pressure equalizing pipeline 400, the flushing pipeline 500, and the venting pipeline 600 are respectively connected to the multiple adsorption towers in a one-to-one corresponding pipeline connection; The pressure swing adsorption method includes: multiple adsorption towers are cyclically operated according to the adsorption step, the first pressure equalization and pressure reduction step, the second pressure equalization and pressure reduction step, the forward release step, the third pressure equalization and pressure reduction step, the reverse release step, the flushing step, the third pressure equalization and pressure increase step, the second pressure equalization and pressure increase step, the isolation step, the first pressure equalization and pressure increase step, and the final pressure increase step.

[0026] It should be noted that, for example, the number of adsorption towers is five or six, which is not limited here.

[0027] Specifically, the product gas outlet pipeline 200 is connected to a product gas buffer tank V, and the product gas is passed into the product gas buffer tank V for storage during the adsorption step.

[0028] In an optional embodiment, the number of adsorption towers is 5, and the adsorption towers include adsorption tower T5A, adsorption tower T5B, adsorption tower T5C, adsorption tower T5D, and adsorption tower T5E. The raw gas delivery pipeline 100, the product gas outlet pipeline 200, the final rise pipeline 300, the pressure equalization pipeline 400, the flushing pipeline 500, and the venting pipeline 600 are respectively connected to the adsorption tower T5A, the adsorption tower T5B, the adsorption tower T5C, the adsorption tower T5D, and the adsorption tower T5E by corresponding pipelines. The specific pressure swing adsorption steps are shown in Table 1.

[0029] Table 1 .

[0030] Among them, A: adsorption step; ED1: first equalizing and reducing pressure step; E2D: second equalizing and reducing pressure step; PP: forward release step; E3D: third equalizing and reducing pressure step; D: reverse release step; P: flushing step; E3R: third equalizing and increasing pressure step; E2R: second equalizing and increasing pressure step; E1R: first equalizing and increasing pressure step; IS: isolation step; FR: final increase step.

[0031] Specifically, T1, T2, and T3 represent a time period. The order of the adsorption towers from top to bottom in the table is adsorption tower T5A, adsorption tower T5B, adsorption tower T5C, adsorption tower T5D, and adsorption tower T5E. The process of each adsorption tower is adsorption step → first pressure equalization and pressure reduction step → second pressure equalization and pressure reduction step → forward release step → third pressure equalization and pressure reduction step → reverse release step → flushing step → third pressure equalization and pressure boosting step → second pressure equalization and pressure boosting step → isolation step → first pressure equalization and pressure boosting step → final pressure boosting step, which runs in a cycle.

[0032] In an optional embodiment, program-controlled valves T5A1, T5A2, T5A3, T5A4, T5A5, and T5A6 are respectively provided one by one between the adsorption tower T5A and the raw gas delivery pipeline 100, the product gas outlet pipeline 200, the venting pipeline 600, the final rise pipeline 300, the pressure equalizing pipeline 400, and the flushing pipeline 500; Program-controlled valves T5B1, T5B2, T5B3, T5B4, T5B5 and T5B6 are respectively provided one by one between the adsorption tower T5B and the raw gas delivery pipeline 100, the product gas outlet pipeline 200, the venting pipeline 600, the final rise pipeline 300, the pressure equalizing pipeline 400 and the flushing pipeline 500; Program-controlled valves T5C1, T5C2, T5C3, T5C4, T5C5 and T5C6 are respectively provided one by one between the adsorption tower T5C and the raw gas delivery pipeline 100, the product gas outlet pipeline 200, the venting pipeline 600, the final rise pipeline 300, the pressure equalizing pipeline 400 and the flushing pipeline 500; Program-controlled valves T5D1, T5D2, T5D3, T5D4, T5D5 and T5D6 are respectively provided one by one between the adsorption tower T5D and the raw gas delivery pipeline 100, the product gas outlet pipeline 200, the venting pipeline 600, the final rise pipeline 300, the pressure equalizing pipeline 400 and the flushing pipeline 500; Program-controlled valves T5E1, T5E2, T5E3, T5E4, T5E5 and T5E6 are respectively provided one by one between the adsorption tower T5E and the raw gas delivery pipeline 100, the product gas outlet pipeline 200, the venting pipeline 600, the final rise pipeline 300, the pressure equalizing pipeline 400 and the flushing pipeline 500; The final rise pipeline 300 is also provided with a final rise special valve KV; A regulating valve PV is provided on the product gas outlet pipeline 200; The flow of gas in the raw gas delivery pipeline 100 and the product gas outlet pipeline 200 is controlled by opening or closing the program-controlled valve and the regulating valve, so as to realize the adsorption step; the flow of gas in the venting pipeline 600 is controlled by opening or closing the program-controlled valve, so as to realize the reverse release step; the flow of gas in the final rise pipeline 300 is controlled by opening or closing the program-controlled valve and the final rise special valve, so as to realize the final rise step; the flow of gas in the pressure equalizing pipeline 400 is controlled by opening or closing the program-controlled valve, so as to realize the first pressure equalizing and reducing step, the second pressure equalizing and reducing step, the third pressure equalizing and reducing step, the third pressure equalizing and increasing step, the second pressure equalizing and increasing step and the first pressure equalizing and increasing step; the flow of gas in the flushing pipeline 500 is controlled by opening or closing the program-controlled valve, so as to realize the forward release step and the flushing step.

[0033] There are many ways to open the valve, as long as the control sequence in Table 1 is met.

[0034] Specifically, the adsorption tower T5A is used as the description object, wherein each step is described in detail as follows (when all the following steps are completed, it means that a pressure swing adsorption cycle is completed): When the adsorption tower T5A is in the adsorption step, the programmable valve T5A1, the programmable valve T5A2 and the special valve F for final rise are in the open state, and the other programmable valves directly connected to the adsorption tower T5A are in the closed state. At this time, the programmable valve T5B5 is opened in the T1 time period, the adsorption tower T5A performs adsorption work and boosts the pressure of the adsorption tower T5B through the special valve F for final rise. The adsorption tower T5B is in the first equalizing and boosting step in the T1 time period, the programmable valve T5B2 and the programmable valve T5B4 are opened in the T2 and T3 time periods, and the adsorption tower T5B is in the final rise step. When the adsorption tower T5A is in the first pressure equalization and pressure reduction step, the programmable valve T5A5 is in an open state, and the other programmable valves directly connected to the adsorption tower T5A are in a closed state. At the same time, in the T3 time period, the programmable valve T5C5 is opened, and the first pressure equalization gas of the adsorption tower T5A enters the adsorption tower T5C, and the adsorption tower T5C is in the first pressure equalization and pressure increase step.

[0035] When the adsorption tower T5A is in the second pressure equalization and pressure reduction step, the programmable valve T5A5 is in an open state, and the other programmable valves directly connected to the adsorption tower T5A are in a closed state. At the same time, the programmable valve T5D5 is opened, and the second pressure equalization gas of the adsorption tower T5A enters the adsorption tower T5D, and the adsorption tower T5D is in the second pressure equalization and pressure increase step.

[0036] When the adsorption tower T5A is in the discharge step, the programmable valve T5A6 is in the open state, and the other programmable valves directly connected to the adsorption tower T5A are in the closed state. At the same time, the programmable valve T5E6 is opened, and the discharge gas of the adsorption tower T5A enters the adsorption tower T5E, and the adsorption tower T5E is in the flushing step.

[0037] When the adsorption tower T5A is in the third pressure equalization and pressure reduction step, the programmable valve T5A5 is in an open state, and the other programmable valves directly connected to the adsorption tower T5A are in a closed state. At the same time, the programmable valve T5B5 is opened, the adsorption tower T5B is in the first pressure equalization and pressure increase step, the programmable valve T5C1, the programmable valve T5C2, and the final pressure increase special valve KV are opened, the adsorption tower T5C is in the adsorption step, the programmable valve T5D5 and the programmable valve T5E5 are opened, the adsorption tower T5D is in the first pressure equalization and pressure increase step, and the adsorption tower T5E is in the third pressure equalization and pressure increase step.

[0038] When the adsorption tower T5A is in the reverse step, the program-controlled valve T5A3 is in an open state, while the other program-controlled valves directly connected to the adsorption tower T5A are in a closed state, and the adsorption tower T5A discharges the desorbed gas by the pressure of the gas itself.

[0039] When adsorption tower T5A is in the flushing step, the programmable valve T5A6 is in the open state, while the others directly connected to adsorption tower T5A are in the closed state. At the same time, the programmable valve T5B6 is opened, and the downstream gas of adsorption tower T5B will enter adsorption tower T5A, and adsorption tower T5B is in the downstream step.

[0040] When the adsorption tower T5A is in the third equalizing and increasing pressure step, the programmable valve T5A5 is in an open state, while the other programmable valves directly connected to the adsorption tower T5A are in a closed state. At the same time, the programmable valve T5C5 is open, and the adsorption tower T5C is in the first equalizing and decreasing pressure step.

[0041] When the adsorption tower T5A is in the second equalizing and boosting step, the programmable valve T5A5 is in an open state, while the other programmable valves directly connected to the adsorption tower T5A are in a closed state. At the same time, the programmable valve T5D6 is open, and the adsorption tower T5D is in the adsorption step.

[0042] When the adsorption tower T5A is in the isolation step, the program-controlled valve T5A5 is in the open state, and the other program-controlled valves directly connected to the adsorption tower T5A are in the closed state. At the same time, the program-controlled valve T5E4 and the final rise special valve KV are opened, and the adsorption tower T5E is in the final rise step.

[0043] When the adsorption tower T5A is in the first equalizing and pressure-increasing step, the program-controlled valve T5A5 is in an open state, and the other program-controlled valves directly connected to the adsorption tower T5A are in a closed state. At the same time, the program-controlled valve T5B5 is open, and the adsorption tower T5B is in the third equalizing and pressure-increasing step.

[0044] When the adsorption tower T5A is in the final ascent step, the programmable valve T5A6 and the special valve KV for final ascent are in the open state, while the other programmable valves directly connected to the adsorption tower T5A are in the closed state. At the same time, the programmable valve T5E6 is opened, and part of the gas from the adsorption tower T5E will enter the adsorption tower T5A, and the adsorption tower T5E is in the adsorption step.

[0045] By setting a program-controlled valve and controlling the opening or closing of the program-controlled valve to ensure the automatic operation of the entire system, the control of product purity and its flow rate is achieved through online fully automatic adjustment. The pressure swing adsorption method that completes the cyclic operation by program control has a high level of intelligence.

[0046] In an optional embodiment, in the same time period, one and only one of the adsorption tower T5A, adsorption tower T5B, adsorption tower T5C, adsorption tower T5D, and adsorption tower T5E must be in the adsorption step.

[0047] Specifically, in the same time period, only one of the five towers must be in the adsorption step, and the process is reasonably designed so that the adsorption tower is always in high-pressure adsorption and low-pressure desorption, thereby ensuring that the adsorption separation process is in a reasonable state.

[0048] In an optional embodiment, the number of adsorption towers is 6, including adsorption tower T6A, adsorption tower T6B, adsorption tower T6C, adsorption tower T6D, adsorption tower T6E and adsorption tower T6F, and the raw gas delivery pipeline 100, the product gas outlet pipeline 200, the final rise pipeline 300, the pressure equalization pipeline 400, the flushing pipeline 500 and the venting pipeline 600 are respectively connected to the adsorption tower T6A, the adsorption tower T6B, the adsorption tower T6C, the adsorption tower T6D, the adsorption tower T6E and the adsorption tower T6F by corresponding pipelines; the specific pressure swing adsorption steps are shown in Table 2.

[0049] Table 2 .

[0050] Among them, A: adsorption step; ED1: first equalizing and reducing pressure step; E2D: second equalizing and reducing pressure step; PP: forward release step; E3D: third equalizing and reducing pressure step; D: reverse release step; P: flushing step; E3R: third equalizing and increasing pressure step; E2R: second equalizing and increasing pressure step; E1R: first equalizing and increasing pressure step; IS: isolation step; FR: final increase step.

[0051] In an optional embodiment, when any one of the multiple adsorption towers is in the first pressure equalization and pressure reduction step, one of the remaining adsorption towers must be connected to the pressure equalization pipeline 400 and transport gas, and is in the first pressure equalization and pressure increase step; When any one of the multiple adsorption towers is in the second pressure equalization and pressure reduction step, one of the remaining adsorption towers must be connected to the pressure equalization pipeline 400 and transport gas, and is in the second pressure equalization and pressure increase step; When any one of the multiple adsorption towers is in the third pressure equalization and pressure reduction step, one of the remaining adsorption towers must be connected to the pressure equalization pipeline 400 to transport gas and is in the third pressure equalization and pressure increase step.

[0052] Specifically, by making the first equalizing pressure step-down step correspond to the first equalizing pressure boosting step, making the second equalizing pressure step-down step correspond to the second equalizing pressure boosting step, and making the third equalizing pressure step-down step correspond to the third equalizing pressure boosting step, the control system is simplified, the operating difficulty is reduced, the process efficiency is improved, and the operating cost is reduced.

[0053] In an optional embodiment, when one of the multiple adsorption towers is in the sequential placement step, one of the remaining adsorption towers must be connected to the flushing pipeline 500 and transport gas, and is in the flushing step.

[0054] Specifically, by making the placing step and the flushing step correspond to each other, the control system is simplified, the operation difficulty is reduced, the process efficiency is improved, and the operation cost is reduced.

[0055] In an optional embodiment, when one of the multiple adsorption towers is in the adsorption step, at least one adsorption tower is in the inversion step.

[0056] Specifically, by rationally configuring the working time of the adsorption tower, the working efficiency of the entire pressure swing adsorption system is further improved.

[0057] In an optional embodiment, in the adsorption step, the first pressure equalizing and reducing step, the second pressure equalizing and reducing step, the forward release step, the third pressure equalizing and reducing step, the reverse release step, the flushing step, the third pressure equalizing and boosting step, the second pressure equalizing and boosting step, the isolation step, the first pressure equalizing and boosting step, and the final boosting step, the starting pressure, the ending pressure, and the working time required for the corresponding steps are as shown in Table 3.

[0058] Table 3 .

[0059] Specifically, when the number of adsorption towers is five, the pressure at the beginning of each step, the pressure at the end of each step, and the working time required for the corresponding step are shown in Table 3.

[0060] In an optional embodiment, in the adsorption step, the first pressure equalizing and reducing step, the second pressure equalizing and reducing step, the forward release step, the third pressure equalizing and reducing step, the reverse release step, the flushing step, the third pressure equalizing and boosting step, the second pressure equalizing and boosting step, the isolation step, the first pressure equalizing and boosting step, and the final boosting step, the starting pressure, the ending pressure, and the working time required for the corresponding steps are as shown in Table 4.

[0061] Table 4 .

[0062] Specifically, when the number of adsorption towers is six, the pressure at the start of each step, the pressure at the end, and the working time required for the corresponding step are shown in Table 4. By setting the pressure at the start of each step, the pressure at the end, and the working time required for the corresponding step, the corresponding adsorbent dosage ratio is set to ensure the purity and flow rate of the product gas.

[0063] The above description is intended to be illustrative rather than restrictive, and those skilled in the art may make changes, modifications, substitutions and variations to the above embodiments within the scope of the present disclosure. Moreover, the above examples (or one or more of them) may be used in combination with each other, and it is contemplated that these embodiments may be combined with each other in various combinations or permutations.

Claims

1. A pressure swing adsorption method, the pressure swing adsorption method is used in a pressure swing adsorption system, characterized in that: The pressure swing adsorption system comprises: At least five adsorption towers, a product gas buffer tank V, a raw gas delivery pipeline, a product gas outlet pipeline, a final rise pipeline, a pressure equalizing pipeline, a flushing pipeline, and a venting pipeline. The product gas buffer tank V is connected to the product gas outlet pipeline. The raw gas delivery pipeline, the product gas outlet pipeline, the final rise pipeline, the pressure equalizing pipeline, the flushing pipeline, and the venting pipeline are respectively connected to the multiple adsorption towers in a one-to-one corresponding pipeline manner; The pressure swing adsorption method includes: multiple adsorption towers are cyclically operated according to the adsorption step, the first pressure equalization and pressure reduction step, the second pressure equalization and pressure reduction step, the forward release step, the third pressure equalization and pressure reduction step, the reverse release step, the flushing step, the third pressure equalization and pressure increase step, the second pressure equalization and pressure increase step, the isolation step, the first pressure equalization and pressure increase step, and the final pressure increase step.

2. The pressure swing adsorption method according to claim 1, characterized in that: The adsorption tower includes an adsorption tower T5A, an adsorption tower T5B, an adsorption tower T5C, an adsorption tower T5D, and an adsorption tower T5E. The raw gas delivery pipeline, the product gas outlet pipeline, the final rise pipeline, the pressure equalization pipeline, the flushing pipeline, and the venting pipeline are respectively connected to the adsorption tower T5A, the adsorption tower T5B, the adsorption tower T5C, the adsorption tower T5D, and the adsorption tower T5E in a one-to-one corresponding pipeline connection; The specific steps of the pressure swing adsorption method are shown in the following table: Among them, A: adsorption step; ED1: first equalizing and reducing pressure step; E2D: second equalizing and reducing pressure step; PP: forward release step; E3D: third equalizing and reducing pressure step; D: reverse release step; P: flushing step; E3R: third equalizing and increasing pressure step; E2R: second equalizing and increasing pressure step; E1R: first equalizing and increasing pressure step; IS: isolation step; FR: final increase step.

3. The pressure swing adsorption method according to claim 2, characterized in that: The pressure swing adsorption system further comprises: The adsorption tower T5A and the raw gas delivery pipeline, the product gas outlet pipeline, the venting pipeline, the final rise pipeline, the pressure equalizing pipeline, and the flushing pipeline are respectively provided with program-controlled valves T5A1, T5A2, T5A3, T5A4, T5A5, and T5A6 in one-to-one correspondence; The adsorption tower T5B and the raw gas delivery pipeline, the product gas outlet pipeline, the venting pipeline, the final rise pipeline, the pressure equalization pipeline, and the flushing pipeline are respectively provided with program-controlled valves T5B1, T5B2, T5B3, T5B4, T5B5, and T5B6 in a one-to-one correspondence; The adsorption tower T5C and the raw gas delivery pipeline, the product gas outlet pipeline, the venting pipeline, the final rise pipeline, the pressure equalizing pipeline, and the flushing pipeline are respectively provided with program-controlled valves T5C1, T5C2, T5C3, T5C4, T5C5, and T5C6 in one-to-one correspondence; The adsorption tower T5D and the raw gas delivery pipeline, the product gas outlet pipeline, the venting pipeline, the final rise pipeline, the pressure equalization pipeline, and the flushing pipeline are respectively provided with program-controlled valves T5D1, T5D2, T5D3, T5D4, T5D5, and T5D6 in a one-to-one correspondence; The adsorption tower T5E and the raw gas delivery pipeline, the product gas outlet pipeline, the venting pipeline, the final rise pipeline, the pressure equalization pipeline, and the flushing pipeline are respectively provided with program-controlled valves T5E1, T5E2, T5E3, T5E4, T5E5, and T5E6 in a one-to-one correspondence; The final rise pipeline is also provided with a final rise special valve KV; A regulating valve PV is provided on the product gas outlet pipeline; The flow of gas in the raw gas delivery pipeline and the product gas outlet pipeline is controlled by opening or closing the program-controlled valve and the regulating valve to realize the adsorption step; the flow of gas in the venting pipeline is controlled by opening or closing the program-controlled valve to realize the reverse release step; the flow of gas in the final rise pipeline is controlled by opening or closing the program-controlled valve and the final rise special valve to realize the final rise step; the flow of gas in the pressure equalizing pipeline is controlled by opening or closing the program-controlled valve to realize the first pressure equalizing step, the second pressure equalizing step, the third pressure equalizing step, the third pressure equalizing step, the second pressure equalizing step and the first pressure equalizing step; the flow of gas in the flushing pipeline is controlled by opening or closing the program-controlled valve to realize the forward release step and the flushing step.

4. The pressure swing adsorption method according to claim 2, characterized in that: In the same time period, only one of the adsorption tower T5A, the adsorption tower T5B, the adsorption tower T5C, the adsorption tower T5D and the adsorption tower T5E must be in the adsorption step.

5. The pressure swing adsorption method according to claim 1, characterized in that: The adsorption tower includes an adsorption tower T6A, an adsorption tower T6B, an adsorption tower T6C, an adsorption tower T6D, an adsorption tower T6E and an adsorption tower T6F, and the raw gas delivery pipeline, the product gas outlet pipeline, the final rise pipeline, the pressure equalization pipeline, the flushing pipeline, and the venting pipeline are respectively connected to the adsorption tower T6A, the adsorption tower T6B, the adsorption tower T6C, the adsorption tower T6D, the adsorption tower T6E and the adsorption tower T6F in a one-to-one corresponding pipeline connection; The specific steps of the pressure swing adsorption method are shown in the following table: Among them, A: adsorption step; ED1: first equalizing and reducing pressure step; E2D: second equalizing and reducing pressure step; PP: forward release step; E3D: third equalizing and reducing pressure step; D: reverse release step; P: flushing step; E3R: third equalizing and increasing pressure step; E2R: second equalizing and increasing pressure step; E1R: first equalizing and increasing pressure step; IS: isolation step; FR: final increase step.

6. The pressure swing adsorption method according to claim 1, characterized in that: Also includes: When any one of the plurality of adsorption towers is in the first pressure equalization and pressure reduction step, one of the remaining adsorption towers must be connected to the pressure equalization pipeline and transport gas, and is in the first pressure equalization and pressure increase step; When any one of the plurality of adsorption towers is in the second pressure equalization and pressure reduction step, one of the remaining adsorption towers must be connected to the pressure equalization pipeline and transport gas, and is in the second pressure equalization and pressure increase step; When any one of the multiple adsorption towers is in the third pressure equalization and pressure reduction step, one of the remaining adsorption towers must be connected to the pressure equalization pipeline and transport gas, and is in the third pressure equalization and pressure increase step.

7. The pressure swing adsorption method according to claim 1, characterized in that: When one of the multiple adsorption towers is in the sequential placement step, one of the remaining adsorption towers must be connected to the flushing pipeline and transport gas, and is in the flushing step.

8. The pressure swing adsorption method according to claim 1, characterized in that: When one of the plurality of adsorption towers is in the adsorption step, at least one adsorption tower is in the inversion step.

9. The pressure swing adsorption method according to claim 2, characterized in that: In the adsorption step, the first pressure-equalizing and pressure-reducing step, the second pressure-equalizing and pressure-reducing step, the forward release step, the third pressure-equalizing and pressure-reducing step, the reverse release step, the flushing step, the third pressure-equalizing and pressure-raising step, the second pressure-equalizing and pressure-raising step, the isolation step, the first pressure-equalizing and pressure-raising step, and the final pressure-raising step, the starting pressure, the ending pressure, and the working time required for the corresponding steps are: 。 10. The pressure swing adsorption method according to claim 5, characterized in that: In the adsorption step, the first pressure-equalizing and pressure-reducing step, the second pressure-equalizing and pressure-reducing step, the forward release step, the third pressure-equalizing and pressure-reducing step, the reverse release step, the flushing step, the third pressure-equalizing and pressure-raising step, the second pressure-equalizing and pressure-raising step, the isolation step, the first pressure-equalizing and pressure-raising step, and the final pressure-raising step, the starting pressure, the ending pressure, and the working time required for the corresponding steps are: 。

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