WO2021207906A1

WO2021207906A1 - Method for mobile pressure swing adsorption oxygen production device

Info

Publication number: WO2021207906A1
Application number: PCT/CN2020/084593
Authority: WO
Inventors: 宋宇文
Original assignee: 成都盈辰科技有限公司
Priority date: 2020-04-14
Filing date: 2020-04-14
Publication date: 2021-10-21
Also published as: CN111989149A

Abstract

A method for mobile pressure swing adsorption oxygen production device, comprising a first pressure swing adsorption section and a second pressure swing adsorption section operated in series. The first pressure swing adsorption section adsorbs oxygen in raw material air by means of a velocity selective adsorbent bed layer. The second pressure swing adsorption section adsorbs nitrogen in an oxygen-rich resolving gas flowing from the first pressure swing adsorption section by means of a nitrogen equilibrium selective adsorbent bed layer. The adsorption tower of the first pressure swing adsorption section at least sequentially undergoes four pressure swing adsorption process steps of adsorption A, serial displacement P1, oxygen-rich displacement P and vacuum evacuation VC in one cycle period. The adsorption tower of the second pressure swing adsorption section at least successively undergoes pressure swing adsorption process steps of adsorption A, equal pressure drop ED, back discharging BD or vacuum evacuation VC, equal pressure rise ER and product gas pressure rise FR in one cycle. The pressure swing adsorption device using the described method has a small volume and a light weight, is convenient to use, and has a low pressure, greatly reduces the cost of using oxygen, and significantly improves the safety of using oxygen.

Description

Method for mobile pressure swing adsorption oxygen production device

Technical field

The invention relates to the field of pressure swing adsorption technology oxygen production, in particular to a method for a mobile pressure swing adsorption oxygen production device.

Background technique

At present, the pure oxygen used in the gas cutting process is produced by a cryogenic device. The pure oxygen is compressed to 12.5MPa or more with a compressor and loaded into a special 40-liter steel cylinder, and then transported to each user. The operating pressure is lower than 0.95MPa, which consumes a lot of manpower and material resources, not only the cost of oxygen is high, but also the safety is poor.

Summary of the invention

The purpose of the present invention is to provide a method for a mobile pressure swing adsorption oxygen production device that is small in size, light in weight, open and stopped at any time, convenient to use and low in pressure, which greatly reduces the cost of oxygen and improves the safety of oxygen use. The purpose of the present invention is achieved through the following technical solutions:

A method for a mobile pressure swing adsorption oxygen production device, which includes two stages of pressure swing adsorption in series operation. The dried raw material air first enters the speed selective adsorbent bed from the bottom of the adsorption tower of the first pressure swing adsorption section. Most of the oxygen in the adsorbent is adsorbed by the speed-selective adsorbent bed, most of the nitrogen and argon are discharged from the outlet of the adsorption tower, and the oxygen-rich, a small amount of nitrogen and argon desorbed from the first PSA section are adsorbed from the second PSA The bottom of the adsorption tower of the section enters the nitrogen balance selective adsorbent bed, the nitrogen in the oxygen-rich mixed gas is adsorbed by the nitrogen balance selective adsorbent bed, and oxygen, argon and a small amount of nitrogen flow out of the adsorption tower outlet. The adsorption tower of the first pressure swing adsorption section undergoes at least four pressure swing adsorption process steps in sequence in one cycle: adsorption A, series displacement P1, oxygen-rich displacement P, and vacuum VC; the adsorption tower of the second pressure swing adsorption section In one cycle, at least the process steps of adsorption A, equalization pressure drop ED, reverse discharge BD or vacuum VC, equalization pressure rise ER, and product gas pressure rise FR pressure swing adsorption are carried out in sequence.

Furthermore, the adsorption tower of the second pressure swing adsorption stage adds a PP step after the equalizing pressure drop ED step, and adds a purge P step after the reverse BD step. The gas in the PP step enters the buffer tank V to purge P The gas in the step comes from the buffer tank V and enters from the top of the adsorption tower.

Further, considering that the raw material air entering the adsorption tower of the first pressure swing adsorption section may contain gaseous water, in order to ensure the adsorption effect of the adsorbent bed, the present invention provides two solutions:

Scheme 1: The bottom of the adsorption tower of the first pressure swing adsorption section is filled with desiccant, and the upper loading speed selective adsorbent bed. When the raw material air passes through the bottom of the adsorption tower of the first pressure swing adsorption section, most of its gaseous water is The desiccant bed is adsorbed, most of the oxygen is adsorbed by the speed-selective adsorbent bed, most of the nitrogen and argon are discharged from the outlet of the adsorption tower, and the desorbed gaseous water and oxygen-rich are from the bottom of the adsorption tower of the second pressure swing adsorption section Entering the desiccant bed and nitrogen balance selective adsorbent bed, most of the gaseous water in the oxygen-enriched bed is adsorbed by the desiccant bed, most of the nitrogen is adsorbed by the nitrogen balance selective adsorbent bed, oxygen and argon gas and A small amount of nitrogen flows out from the outlet of the adsorption tower.

Option 2: Add a pressure swing adsorption drying section before the first pressure swing adsorption section to remove gaseous water in the air and dry the air to meet the moisture requirements of the adsorption tower entering the first pressure swing adsorption section; The pressure adsorption drying section sequentially undergoes two pressure swing adsorption process steps of adsorption A and purge P in one cycle. The gas of the purge P step comes from the vented air and the outlet of the adsorption step A of the adsorption tower of the first pressure swing adsorption section. The adsorption tower of the second pressure swing adsorption section decomposes air. The drying section is filled with activated alumina; the adsorption tower of the first pressure swing adsorption section is filled with carbon molecular sieves; the adsorption tower of the second pressure swing adsorption section is filled with 5A type molecular sieves or X type lithium molecular sieves.

Further, the pressure of the adsorption step A in the adsorption tower of the first pressure swing adsorption section is 0.002-0.01 MPa (gauge pressure); the pressure of the adsorption step A of the adsorption tower in the second pressure swing adsorption section is 0.8-1.2 MPa (gauge pressure).

Furthermore, the concentration of oxygen in the outlet gas at the end of the adsorption step A of the adsorption tower of the first pressure swing adsorption section is 15-20% (V).

Further, the adsorption tower of the first pressure swing adsorption section is filled with carbon molecular sieve as the speed selective adsorbent; the adsorption tower of the second pressure swing adsorption section is filled with 5A molecular sieve or X type lithium molecular sieve as the nitrogen balance selective adsorbent.

The mobile pressure swing adsorption pure oxygen production device provided by the method of the present invention greatly reduces the cost of oxygen, and the safety is greatly improved. The mobile pressure swing adsorption pure oxygen production device is small in size, light in weight, and stops at any time. , Easy to use, the maximum pressure is only 1.2MPa.

Description of the drawings

Fig. 1 is a timing diagram of the operation steps of each stage of the adsorption tower and the switching of the programmable valve in the embodiment 1 of the present invention.

Figure 2 is a process flow diagram of Example 1 of the present invention.

Fig. 3 is a time sequence diagram of the operation steps of each stage of the adsorption tower and the switch of the programmable valve in the second embodiment of the present invention.

Fig. 4 is a process flow diagram of Example 2 of the present invention.

Fig. 5 is a time sequence diagram of the operation steps of each stage of the adsorption tower and the switch of the programmable valve in the embodiment 3 of the present invention.

Fig. 6 is a process flow diagram of Example 3 of the present invention.

Fig. 7 is a time sequence diagram of the operation steps of each stage of the adsorption tower and the switching of the programmable valve in the embodiment 4 of the present invention.

Fig. 8 is a process flow diagram of Example 4 of the present invention.

Detailed ways

The preferred embodiments of the present invention will be described below in conjunction with the accompanying drawings. The following embodiments are only preferred embodiments for facilitating the understanding of the technical solutions of the present invention, and are not intended to limit the scope of protection of the claims of the present invention.

Example 1:

Figure 2 is a schematic diagram of the process flow of Example 1 of the present invention.

The composition of the raw air in this embodiment is as follows:

组份Component	O ₂ O ₂	N ₂ N ₂	ArAr	CO ₂ CO ₂	其它other	∑∑
浓度(％)(V)Concentration (%) (V)	20.9320.93	78.0378.03	0.9320.932	0.030.03	0.0780.078	100100

Temperature: ≤40℃

Pressure: 0.005MPa(G) (higher adsorption pressure can also be used)

As shown in Figure 2, the oxygen-enriched vacuum pump P0101, programmable valve, PLC control system, instrumentation, process pipe fittings, adsorption towers T0101A, T0101B, T0101C and T0101D constitute the first pressure swing adsorption section. The adsorbent filled in the adsorption tower is Carbon molecular sieve, run single tower adsorption, series replacement and vacuuming procedures; programmable valve, PLC control system, instrumentation, process pipe fittings, oxygen-enriched compressor C0201, compressor buffer tank V0201, product pure oxygen buffer tank V0202, adsorption tower T0201A, T0201B, T0201C and T0201D constitute the second pressure swing adsorption section. The adsorbent filled in the adsorption tower is zeolite molecular sieve or lithium molecular sieve, and the single-tower adsorption, two pressure equalization and reverse discharge procedures are run. In this embodiment, the above-mentioned two pressure swing adsorption stages are operated in series. The first pressure swing adsorption stage adsorbs oxygen in the dry air, and the second pressure swing adsorption stage is used to mix the oxygen-rich mixture desorbed from the vacuum of the first pressure swing adsorption stage. The nitrogen in the gas is adsorbed, and the oxygen that is not easily adsorbed flows out from the outlet of the adsorption tower as a product, and the oxygen concentration is increased to 99.5% (V) or more.

Dry air with a pressure greater than 5KPa enters the adsorption tower in the first pressure swing adsorption stage in the adsorption step. The adsorbent in the adsorption tower selectively adsorbs oxygen and other components in the air, unadsorbed part of oxygen, and difficult-to-adsorb nitrogen and argon. The other components are discharged and vented from the outlet end. After the adsorption of dry air in the adsorption tower of the first PSA section is completed, the series replacement P1 and the oxygen-enriched gas replacement P are carried out. After the replacement is completed, vacuum is drawn. The adsorption tower of the first PSA section The oxygen-enriched gas mixture desorbed by vacuum is compressed to 1.0-1.2MPa by the oxygen-enriched compressor C0201, and then enters the adsorption tower in the second pressure swing adsorption section in the adsorption step. After the nitrogen is adsorbed, it flows out from the outlet as product oxygen. Control above 99.5% (V). After the adsorption of the adsorption tower of the first pressure swing adsorption stage is completed, the oxygen concentration in the outlet gas is controlled at 15-20.8% (V) (the oxygen concentration can also be controlled below 15% (V)), and the adsorption tower is in a cycle Go through the four pressure swing adsorption process steps of adsorption A, serial displacement P1, oxygen-rich gas displacement P, and vacuum VC; the adsorption tower of the second pressure swing adsorption section undergoes adsorption A and two equal pressure drops in one cycle. , Reverse discharge BD, two equal pressure rise and final rise seven pressure swing adsorption process steps, the nitrogen, oxygen and argon mixed gas analyzed in the reverse discharge BD step is returned to the first pressure swing adsorption section and mixed with the replaced part of the vacuum desorption gas. The total recovery rate of oxygen is about 60%, the oxygen concentration of the vacuum desorption gas in the first PSA section is about 80%, the cycle time of the two stages is generally 20-80 seconds, the vacuum degree of the first PSA section is -0.095MPa, blower The gas volume, the empty tower speed of the two-stage adsorption tower, the suction volume of the vacuum pump, the amount of adsorbent, the diameter of the adsorption tower, and other design parameters are designed according to the usual conditions in the field of pressure swing adsorption technology.

Each adsorption tower in this embodiment sequentially undergoes the following steps in a cycle.

The first pressure swing adsorption section

⑴Adsorption A

Open the programmable valve KV1A-1 of the first pressure swing adsorption section, the dry air enters the adsorption tower T0101A adsorbent bed from the bottom to increase the pressure, when the adsorption pressure is raised, then open the programmable valve KV2A-1, the adsorption in the adsorption tower T0101A The adsorbent selectively adsorbs oxygen and other components in the dry air. The unadsorbed part of the oxygen and the difficult-to-adsorb nitrogen and argon tail gas flow out and vent from the outlet end. As time goes by, the total amount of adsorbed oxygen continues to increase. When the oxygen concentration at the outlet of the adsorption tower T0101A is greater than 15-20.8% (V) (the oxygen concentration can also be controlled below 15% (V)), stop the air intake, and the adsorption ends at this time.

⑵Tandem replacement P1

After the adsorption step A is over, close the program-controlled valves KV1A-1 and KV2A-1, and open the program-controlled valves KV5D-1, KV3D-1 and KV2A-1. Part of the oxygen-enriched gas evacuated in this section and the second pressure swing adsorption section After the desorption gas is mixed, it enters the adsorbent bed from the bottom of the adsorption tower T0101D to replace nitrogen and argon, and then flows out from the top. The replacement tail gas flowing out of the top enters from the bottom of the adsorption tower T0101A, and passes through the adsorption tower T0101A adsorbent bed to adsorb oxygen. Vent through the programmable valve KV2A-1.

⑶ Oxygen-rich gas replacement P

After the series replacement P1 step is completed, close the program-controlled valves KV5D-1, KV3D-1 and KV2A-1, open the program-controlled valves KV5A-1 and KV3A-1, part of the oxygen-enriched gas evacuated in this section and the second pressure swing adsorption section After mixing, the desorption gas from the bottom of the adsorption tower T0101A enters the adsorbent bed to replace nitrogen and argon, and then flows out from the top. The replacement tail gas from the top enters from the bottom of the adsorption tower T0101B, and passes through the adsorption tower T0101B adsorbent bed to adsorb oxygen. , Vent through the program-controlled valve KV2B-1.

⑷Vacuum VC

After the oxygen replacement P of the adsorption tower T0101A product is completed, close the program control valves KVKV5A-1, KV3A-1 and KV2B-1, open the program control valve KV4A-1 to extract the oxygen adsorbed by the adsorbent from the bottom of the adsorption tower with a vacuum pump, and part of the oxygen-enriched gas As the raw material gas of the second PSA section, the other part is returned to this section as the replacement gas to replace the adsorbent bed.

After the above steps, the adsorption tower T0101A completes a cycle and enters the oxygen-rich feed gas adsorption again. The steps and sequence of the other three adsorption towers are exactly the same as the adsorption tower T0101A, except that they are staggered in time.

The second pressure swing adsorption section

⑴Adsorption A

Open the programmable valve KV1A-2 of the second pressure swing adsorption section, and compress the oxygen-enriched gas mixture extracted from the vacuum (VC) step of the adsorption tower of the first pressure swing adsorption section to 1.0-1.2MPa through the oxygen-enriched compressor C0201. The bottom is sent to the adsorbent bed of the adsorption tower T0201A. The adsorbent in the adsorption tower T0201A selectively adsorbs the nitrogen and other components in the oxygen-rich mixed gas, and the unadsorbed part of the nitrogen and the difficult-to-adsorb oxygen and argon components are opened for program control The valve KV2A-2 flows out from the outlet end into the product pure oxygen buffer tank V0202 to control the product oxygen concentration above 99.5% (V). As time goes by, the total amount of nitrogen and other components adsorbed by the adsorbent continues to increase. When the adsorption tower T0201A is saturated with nitrogen, stop the gas supply, and the adsorption ends at this time.

⑵E1D reduction

After the adsorption is over, close the program-controlled valves KV1A-2 and KV2A-2, and open the program-controlled valves KV3A-2 and KV3C-2. The dead space gas in the adsorption tower T0201A is discharged from the outlet of the adsorption tower and enters this stage. The adsorption step has been completed. The pressure of tower T0201C is increased, and the pressure of the two towers should be equal as much as possible.

⑶ Reduce both E2D

After the E1D step is finished, close the programmable valve KV3C-2 and open the programmable valve KV3D-2. The dead space gas in the adsorption tower T0201A is discharged from the outlet of the adsorption tower into the adsorption tower T0201D that has completed the reverse discharge BD step to increase the pressure. Try to make the pressures of the two towers equal.

⑷Reverse release BD

After the step of reducing both E2D in the adsorption tower T0201A, close the program control valves KV3A-2 and KV3D-2, open the program control valve KV4A-2, and desorb the nitrogen, oxygen and argon adsorbed in the adsorption tower T0201A and return to the first pressure swing adsorption The section and its replacement part are mixed with the vacuum desorption gas, and at the same time the adsorbent in the adsorption tower T0201A is regenerated.

⑸E2R is up to two

After the BD step of the adsorption tower T0201A is completed, close the program control valve KV4A-2, open the program control valves KV3A-2 and KV3B-2, and use the gas discharged from the adsorption tower T0201B to reduce the E2D step and enter the adsorption tower from the outlet end of the adsorption tower T0201A , Increase the pressure of the adsorption tower T0201A, try to make the pressure of the adsorption tower T0201A and T0201B equal.

⑹ One E1R

After the two equalizing E2R step of the adsorption tower T0201A is over, close the program control valve KV3B-2, open the program control valve KV3C-2, and use the gas discharged from the adsorption tower T0201C-E1D step to enter the adsorption tower from the outlet end of the adsorption tower T0201A to make the adsorption Increase the pressure of tower T0201A, try to make the pressure of adsorption tower T0201A and T0201C equal.

⑺Final boost FR

After the E1R equalization is over, close the programmable valve KV3C-2, open the programmable valve KV2A-2, and use the outlet gas from the adsorption process to boost the pressure of the adsorption tower T0201A until it is close to the adsorption pressure of the second PSA section.

The result of this embodiment is that the oxygen concentration of the product is greater than or equal to 99.5% (V), and the pressure is greater than or equal to normal pressure, which saves power consumption by about 10% compared with the cryogenic method.

This embodiment can also be used to produce product oxygen with a concentration of less than 99.5% (V). Compared with the traditional cryogenic method and pressure swing adsorption method, the power consumption can be saved by about 10%-20%. The lower the oxygen concentration of the product, the lower the power consumption. more.

Example 2:

Figure 4 is a schematic diagram of the process flow of Example 2 of the present invention.

The composition of the raw air in this embodiment is as follows:

Temperature: ≤40℃

Pressure: 0.005MPa(G) (higher adsorption pressure can also be used)

As shown in Figure 4, the oxygen-enriched vacuum pump P0101, programmable valve, PLC control system, instrumentation, process pipe fittings, adsorption towers T0101A, T0101B, T0101C and T0101D constitute the first pressure swing adsorption section. The adsorbent filled in the adsorption tower is Carbon molecular sieve, running single tower adsorption, serial displacement and vacuuming procedures; programmable valve, PLC control system, instrumentation, process piping fittings, oxygen-enriched compressor C0201, compressor buffer tank V0201, product pure oxygen buffer tank V0202, sequential release Buffer tank V0203, adsorption towers T0201A, T0201B and T0201C constitute the second pressure swing adsorption section. The adsorbent filled in the adsorption tower is zeolite molecular sieve or lithium molecular sieve, and the single-tower adsorption, equalization, sequential discharge, reverse discharge and purge procedures are run. . In this embodiment, the above-mentioned two pressure swing adsorption stages are operated in series. The first pressure swing adsorption stage adsorbs the oxygen in the dry air, and the second pressure swing adsorption stage is used to mix the oxygen-rich mixture desorbed from the vacuum of the first pressure swing adsorption stage. The nitrogen in the gas is adsorbed, and the oxygen that is not easily adsorbed flows out from the outlet of the adsorption tower as a product, and the oxygen concentration is increased to 99.5% (V) or more.

Dry air with a pressure greater than 5KPa enters the adsorption tower in the first pressure swing adsorption stage in the adsorption step. The adsorbent in the adsorption tower selectively adsorbs oxygen and other components in the air, unadsorbed part of oxygen, and difficult-to-adsorb nitrogen and argon. The other components are discharged and vented from the outlet end. After the adsorption of dry air in the adsorption tower of the first PSA section is completed, the series replacement P1 and the oxygen-enriched gas replacement P are carried out. After the replacement is completed, vacuum is drawn. The adsorption tower of the first PSA section The oxygen-enriched gas mixture desorbed by the vacuum is compressed to 1.0-1.2MPa by the oxygen-enriched compressor C0201, and then enters the adsorption tower in the second pressure swing adsorption section in the adsorption step. After the nitrogen is adsorbed, it flows out from the outlet as product oxygen. The concentration is controlled above 99.5% (V). After the adsorption of the adsorption tower of the first pressure swing adsorption stage is completed, the oxygen concentration in the outlet gas is controlled at 15-20.8% (V) (the oxygen concentration can also be controlled below 15% (V)), and the adsorption tower is in a cycle It goes through four pressure swing adsorption process steps of adsorption A, series replacement P1, oxygen-rich gas replacement P, and vacuum VC; the adsorption tower of the second pressure swing adsorption section sequentially undergoes adsorption A, one pressure drop, and pressure drop in one cycle. There are seven pressure swing adsorption process steps: sequential discharge, reverse discharge, purge, one-time pressure rise and final rise. The total recovery rate of oxygen is about 60%, the oxygen concentration of the vacuum desorption gas in the first PSA section is about 80%, the cycle time of the two stages is generally 20-80 seconds, the vacuum degree of the first PSA section is -0.095MPa, blower The gas volume, the empty tower speed of the two-stage adsorption tower, the suction volume of the vacuum pump, the amount of adsorbent, the diameter of the adsorption tower, and other design parameters are designed according to the usual conditions in the field of pressure swing adsorption technology.

The first pressure swing adsorption section

⑴Adsorption A

Open the programmable valve KV1A-1 of the first pressure swing adsorption section, the dry air enters the adsorption tower T0101A adsorbent bed from the bottom to increase the pressure, when the adsorption pressure is raised, then open the programmable valve KV2A-1, the adsorption in the adsorption tower T0101A The adsorbent selectively adsorbs oxygen and other components in the dry air. The unadsorbed part of the oxygen and the difficult-to-adsorb nitrogen and argon tail gas flow out and vent from the outlet end. As time goes by, the total amount of adsorbed oxygen continues to increase. When the oxygen concentration at the outlet of the adsorption tower T0101A is greater than 15-20.8% (V) (the oxygen concentration can also be controlled below 15% (V)), stop the air intake and the adsorption ends.

⑵Tandem replacement P1

⑶ Oxygen-rich gas replacement P

⑷Vacuum VC

After the oxygen replacement P of the adsorption tower T0101A product is completed, close the program control valves KVKV5A-1, KV3A-1 and KV2B-1, open the program control valve KV4A-1 to extract the oxygen adsorbed by the adsorbent from the bottom of the adsorption tower with a vacuum pump, and part of the oxygen-enriched gas As the feed gas of the second pressure swing adsorption section, the other part is returned to this section as the replacement gas to replace the adsorbent bed.

The second pressure swing adsorption section

⑴Adsorption A

Open the programmable valve KV1A-2 of the second pressure swing adsorption section, and compress the oxygen-enriched gas mixture extracted from the vacuum (VC) step of the adsorption tower of the first pressure swing adsorption section to 1.0-1.2MPa through the oxygen-enriched compressor C0201. The bottom is sent to the adsorbent bed of the adsorption tower T0201A. The adsorbent in the adsorption tower T0201A selectively adsorbs the nitrogen and other components in the oxygen-rich mixed gas, and the unadsorbed part of the nitrogen and the difficult-to-adsorb oxygen and argon components are opened for program control The valve KV2A-2 flows out from the outlet end into the product pure oxygen buffer tank V0202 to control the product oxygen concentration above 99.5% (V). As time goes by, the total amount of nitrogen and other components adsorbed by the adsorbent continues to increase. When the adsorption tower T0201A is saturated with nitrogen, stop the gas supply and the adsorption ends.

⑵Equal pressure drop ED

After the adsorption is over, close the program-controlled valves KV1A-2 and KV2A-2, open the program-controlled valves KV3A-2 and KV3C-2, the dead space gas in the adsorption tower T0201A is discharged from the adsorption tower outlet into the adsorption tower where the purge step P has been completed in this section T0201C increases the pressure, try to make the pressure of the two towers equal.

⑶Sequentially put PP

After the equalizing pressure drop ED step is over, close the programmable valve KV3C-2, open the programmable valve KV6-2, the dead space gas in the adsorption tower T0201A is discharged from the outlet of the adsorption tower into the buffer tank V0203, the pressure will be adjusted as needed.

⑷Reverse release BD

After the PP step of the adsorption tower T0201A is completed, close the program control valves KV3A-2 and KV6-2, open the program control valve KV4A-2, and desorb the nitrogen, oxygen and argon adsorbed by the adsorbent in the adsorption tower T0201A and return to the first pressure swing The adsorption section is mixed with the vacuum desorption gas of its replacement part to allow the adsorbent to be regenerated.

⑸Purge P

After the reverse release BD step, open the program-controlled valves KV3A-2 and KV6-2, the gas in the buffer tank V0201 enters the adsorption tower T0201A from the outlet, and the nitrogen, oxygen and argon adsorbed in the adsorbent bed are purged out and returned The first pressure swing adsorption section is mixed with the vacuum desorption gas of its replacement part to further regenerate the adsorbent.

⑹Equal pressure rise ER

After the purge P step of the adsorption tower T0201A is completed, close the program control valves KV4A-2 and KV6-2, open the program control valve KV3B-2, and use the gas discharged from the adsorption tower T0201B equalizing pressure drop ED step to enter the adsorption tower from the outlet end of the adsorption tower T0201A , Increase the pressure of the adsorption tower T0201A, try to make the pressure of the adsorption tower T0201A and T0201B equal.

⑺Final boost FR

After the equalizing pressure rise ER is over, close the program-controlled valves KV3B-2 and KV3A-2, open the program-controlled valve KV2A-2, and use the outlet gas from the adsorption process to boost the pressure of the adsorption tower T0201A until it is close to the adsorption of the second PSA stage. pressure.

This embodiment can also be used to produce product oxygen with a concentration of less than 99.5% (V). Compared with the traditional cryogenic method and pressure swing adsorption method, the power consumption can be saved by about 10%-20%. The lower the product oxygen concentration, the power consumption can be saved. more.

Example 3:

Fig. 6 is a schematic diagram of the process flow of Example 3 of the present invention.

The composition of the raw air in this embodiment is as follows:

Temperature: ≤40℃

Pressure: 0.005MPa(G) (higher adsorption pressure can also be used)

As shown in Figure 6, the oxygen-enriched vacuum pump P0101, programmable valve, PLC control system, instrumentation, process pipe fittings, adsorption towers T0101A, T0101B, T0101C and T0101D constitute the first pressure swing adsorption section. The adsorbent filled in the adsorption tower is Carbon molecular sieve, running single tower adsorption, serial displacement and vacuuming procedures; programmable valve, PLC control system, instrumentation, process pipe fittings, oxygen-enriched compressor C0201, compressor buffer tank V0201, product pure oxygen buffer tank V0202, vacuum buffer Tank V0203, adsorption towers T0201A, T0201B and T0201C constitute the second pressure swing adsorption section. The adsorbent filled in the adsorption tower is zeolite molecular sieve or lithium molecular sieve, and the single-tower adsorption, equalization, reverse discharge and vacuuming procedures are run. In this embodiment, the above-mentioned two pressure swing adsorption stages are operated in series. The first pressure swing adsorption stage adsorbs the oxygen in the dry air, and the second pressure swing adsorption stage is used to mix the oxygen-rich mixture desorbed from the vacuum of the first pressure swing adsorption stage. The nitrogen in the gas is adsorbed, and the oxygen that is not easily adsorbed flows out from the outlet of the adsorption tower as a product, and the oxygen concentration is increased to 99.5% (V) or more.

Dry air with a pressure greater than 5KPa enters the adsorption tower in the first pressure swing adsorption stage in the adsorption step. The adsorbent in the adsorption tower selectively adsorbs oxygen and other components in the air, unadsorbed part of oxygen, and difficult-to-adsorb nitrogen and argon. The other components are discharged and vented from the outlet end. After the adsorption of dry air in the adsorption tower of the first PSA section is completed, the series replacement P1 and the oxygen-enriched gas replacement P are carried out. After the replacement is completed, vacuum is drawn. The adsorption tower of the first PSA section The oxygen-enriched gas mixture desorbed by vacuum is compressed to 1.0-1.2MPa by the oxygen-enriched compressor C0201, and then enters the adsorption tower in the second pressure swing adsorption section in the adsorption step. After the nitrogen is adsorbed, it flows out from the outlet as product oxygen. Control above 99.5% (V). After the adsorption of the adsorption tower of the first pressure swing adsorption stage is completed, the oxygen concentration in the outlet gas is controlled at 15-20.8% (V) (the oxygen concentration can also be controlled below 15% (V)), and the adsorption tower is in a cycle It goes through four pressure swing adsorption process steps of adsorption A, series replacement P1, oxygen-rich gas replacement P, and vacuum VC; the adsorption tower of the second pressure swing adsorption section sequentially undergoes adsorption A, equal pressure drop ED, There are six pressure swing adsorption process steps: reverse discharge BD, vacuum VC, equal pressure increase ER and final increase. The total recovery rate of oxygen is about 60%, the oxygen concentration of the vacuum desorption gas in the first PSA section is about 80%, the cycle time of the two stages is generally 20-80 seconds, the vacuum degree of the first PSA section is -0.095MPa, blower The gas volume, the empty tower speed of the two-stage adsorption tower, the suction volume of the vacuum pump, the amount of adsorbent, the diameter of the adsorption tower, and other design parameters are designed according to the usual conditions in the field of pressure swing adsorption technology.

The first pressure swing adsorption section

⑴Adsorption A

⑵Tandem replacement P1

⑶ Oxygen-rich gas replacement P

⑷Vacuum VC

After the adsorption tower T0101A oxygen-enriched gas replacement P is completed, close the programmable valves KVKV5A-1, KV3A-1 and KV2B-1, open the programmable valve KV4A-1 from the bottom of the adsorption tower to use a vacuum pump to extract the oxygen adsorbed by the adsorbent, a part of which is enriched in oxygen The body is used as the feed gas in the second PSA section, and the other part is returned to this section as the replacement gas to replace the adsorbent bed.

The second pressure swing adsorption section

⑴Adsorption A

⑵Equal pressure drop ED

After the adsorption is over, close the program-controlled valves KV1A-2 and KV2A-2, open the program-controlled valves KV3A-2 and KV3C-2, the dead space gas in the adsorption tower T0201A is discharged from the outlet of the adsorption tower into the adsorption tower where the vacuum VC step has been completed in this section T0201C increases the pressure, try to make the pressure of the two towers equal.

⑶ Reverse BD

After the ED step of equalizing pressure drop in the adsorption tower T0201A is over, close the program control valves KV3A-2 and KV3C-2, open the program control valves KV4A-2 and KV201-2, and desorb the nitrogen, oxygen and argon adsorbed in the adsorption tower T0201A and return to the second A pressure swing adsorption section is mixed with the vacuum desorption gas of its replacement part, and at the same time the adsorbent in the adsorption tower T0201A is regenerated.

⑷Vacuum VC

After the reverse discharge step of the adsorption tower T0201A is completed, close the program control valve KV201-2, open the program control valve KV202-2 from the bottom of the adsorption tower to desorb the nitrogen, oxygen and argon adsorbed by the adsorbent with a vacuum pump and return to the first pressure swing adsorption section. The replaced part of the vacuum desorption gas is mixed, and the adsorbent is further regenerated. After the vacuuming is completed, the program-controlled valve KV202-2 is closed, the program-controlled valve KV203-2 is opened, and the vacuum pump directly evacuates the buffer tank V0203.

⑸Equal pressure rise ER

After the VC step of vacuuming the adsorption tower T0201A, close the program-controlled valves KV4A-2 and KV202-2, open the program-controlled valves KV3A-2 and KV3B-2, and use the gas discharged from the ED step of the adsorption tower T0201B equal pressure drop from the outlet of the adsorption tower T0201A The end enters the adsorption tower to increase the pressure of the adsorption tower T0201A, and try to make the pressure of the adsorption tower T0201A and T0201B equal.

⑹Final boost FR

After the equalizing pressure rise ER is over, close the program-controlled valves KV3A-2 and KV3B-2, open the program-controlled valve KV2A-2, and use the outlet gas from the adsorption process to boost the pressure of the adsorption tower T0201A until it is close to the adsorption of the second pressure swing adsorption stage. pressure.

After the above steps, the adsorption tower T0201A completes a cycle and enters the oxygen-rich feed gas adsorption again. The steps and sequence of the other two adsorption towers are exactly the same as the adsorption tower T0201A, but they are staggered in time.

Example 4:

Fig. 8 is a schematic diagram of the process flow of Example 4 of the present invention.

The composition of the raw air in this embodiment is as follows:

Temperature: ≤40℃

Pressure: 0.005MPa(G) (higher adsorption pressure can also be used)

As shown in Figure 8, the blower C0100, programmable valve, PLC control system, instrumentation, process pipe fittings, adsorption tower T0100A and T0100B constitute pressure swing adsorption in the drying section. The adsorbent in the adsorption tower is activated alumina desiccant. Single tower adsorption and purging regeneration program; oxygen-enriched vacuum pump P0101, programmable valve, PLC control system, instrumentation, process pipe fittings, adsorption tower T0101A, T0101B, T0101C and T0101D constitute the first pressure swing adsorption section, and the adsorption tower is filled with The adsorbent is carbon molecular sieve, running single tower adsorption, serial displacement and vacuuming procedures; programmable valve, PLC control system, instrumentation, process pipe fittings, oxygen-enriched compressor C0201, compressor buffer tank V0201, product pure oxygen buffer tank V0202 , The adsorption towers T0201A, T0201B, T0201C and T0201D constitute the second pressure swing adsorption section. The adsorbent in the adsorption tower is zeolite molecular sieve or lithium molecular sieve, and the single-tower adsorption, two pressure equalization and reverse discharge procedures are operated. In this embodiment, the above-mentioned three stages of pressure swing adsorption are operated in series, and the pressure swing adsorption in the drying section is used to adsorb gaseous water in the air to meet the water requirements of the pressure swing adsorption oxygen generation adsorbent. The first pressure swing adsorption section will The oxygen in the dry air is adsorbed, and the second PSA section is used to adsorb the nitrogen in the oxygen-rich mixed gas desorbed in the vacuum of the first PSA section. The oxygen that is not easily adsorbed flows out from the outlet of the adsorption tower as a product. The oxygen concentration is increased to more than 99.5% (V).

After the air is boosted to 5KPa by the blower C0100, it enters the pressure swing adsorption in the drying section. The adsorbent in the adsorption tower selectively adsorbs the gaseous water and other components in the humid air, and the components such as oxygen, nitrogen and argon that are not easily adsorbed are from the outlet end. Entering the first pressure swing adsorption stage in the adsorption step of the adsorption tower, the adsorbent in the adsorption tower selectively adsorbs oxygen and other components in the air, and the unadsorbed part of oxygen and the non-adsorbable nitrogen and argon components are from the outlet end The water adsorbed in the regenerated alumina is discharged and returned to the drying section. After the adsorption of dry air in the adsorption tower of the first PSA section is completed, the series replacement P1 and the oxygen-enriched gas replacement P are carried out. After the replacement is completed, vacuum is applied, and the first PSA section The oxygen-enriched gas mixture desorbed by the vacuum of the adsorption tower is compressed to 1.0-1.2MPa by the oxygen-enriched compressor C0201 and then enters the adsorption tower in the second pressure swing adsorption section in the adsorption step. After the nitrogen is adsorbed, it flows out from the outlet as a product The concentration of oxygen is controlled above 99.5% (V). The pressure swing adsorption in the drying section is used to control the dew point of the humid air above -50°C. The adsorption tower undergoes two pressure swing adsorption process steps of adsorption A and purge P in one cycle; the first pressure swing adsorption section After the adsorption of the adsorption tower is completed, the oxygen concentration in the outlet gas is controlled at 15-20.8% (V) (the oxygen concentration can also be controlled below 15% (V)), and the adsorption tower undergoes adsorption A and serial displacement in a cycle. P1, oxygen-enriched gas replacement P and vacuum VC four pressure swing adsorption process steps; the adsorption tower of the second pressure swing adsorption section undergoes adsorption A, two equal pressure drops, reverse discharge BD, and two times in one cycle. There are seven pressure swing adsorption process steps of equalizing pressure rise and final rise, and the mixed gas of nitrogen, oxygen and argon analyzed in the BD step is returned to the first pressure swing adsorption section and mixed with the vacuum analysis gas of the replacement part. The total recovery rate of oxygen is about 60%, the oxygen concentration of the first pressure swing adsorption stage vacuum analysis gas is about 80% (V), the three-stage cycle time is generally 20-80 seconds, and the vacuum degree of the first pressure swing adsorption stage is -0.095 MPa, air volume of blower, empty tower speed of three-stage adsorption tower, suction volume of vacuum pump, amount of adsorbent, diameter of adsorption tower and other design parameters are designed according to the usual conditions in the field of pressure swing adsorption technology.

Pressure swing adsorption drying section

⑴Adsorption A

Open the program-controlled valves KV1A-0 and KV2A-0. After the raw material air is boosted to 5KPa(G) by the blower (C0101), it enters the activated alumina bed from the bottom of the adsorption tower T0100A, and adsorbs the gaseous water in the air, making it difficult to adsorb The oxygen, nitrogen, argon and other components are discharged from the outlet end into the bottom of the adsorption tower of the first pressure swing adsorption section. With the passage of time, the total amount of gaseous water adsorbed by activated alumina is increasing. When the water is saturated, stop the air intake. At this time, the adsorption is over, and the dew point of the mixture at the outlet of the adsorption step A of the PSA drying section is controlled to be about -50°C again.

⑵Purge

After the adsorption of the adsorption tower T0100A is completed, open the programmable valves KV3A-0 and KV4A-0, and the venting of the adsorption tower adsorption A step and the tail gas adsorption A1 step of the first pressure swing adsorption section will pass through the programmed valve KV3A-0 from the outlet end of the adsorption tower T0100A Enter the adsorption tower, and then discharge and vent from the bottom of the adsorption tower T0100A through the process control valve KV4A-0. After the purge of P is completed, close the program control valves KV3A-0 and KV4A-0.

After the above steps, the adsorption tower T0100A completes a cycle and enters the dry air adsorption again. The steps and sequence of the other adsorption tower are exactly the same as the adsorption tower T0100A, except that they are staggered in time.

The first pressure swing adsorption section

⑴Adsorption A

Open the programmable valve KV1A-1 of the first pressure swing adsorption section, the dry air enters the adsorption tower T0101A adsorbent bed from the bottom to increase the pressure, when the adsorption pressure is raised, then open the programmable valve KV2A-1, the adsorption in the adsorption tower T0101A The agent selectively adsorbs the oxygen and other components in the dry air. The unadsorbed part of the oxygen and the difficult-to-adsorb tail gas such as nitrogen and argon flow out from the outlet end and return to the water adsorbed in the regenerated alumina in the drying section. As time goes by, adsorb The total amount of oxygen adsorbed by the agent is continuously increasing. When the oxygen concentration at the outlet of the adsorption tower T0101A is greater than 15-20.8% (V) (the oxygen concentration can also be controlled below 15% (V)), stop the air intake, and the adsorption ends at this time .

⑵Tandem replacement P1

After the adsorption step A is over, close the program-controlled valves KV1A-1 and KV2A-1, and open the program-controlled valves KV5D-1, KV3D-1 and KV2A-1. Part of the oxygen-enriched gas evacuated in this section and the second pressure swing adsorption section After the desorption gas is mixed, it enters the adsorbent bed from the bottom of the adsorption tower T0101D to replace nitrogen and argon, and then flows out from the top. The replacement tail gas flowing out of the top enters from the bottom of the adsorption tower T0101A, and passes through the adsorption tower T0101A adsorbent bed to adsorb oxygen. Return to the drying section through the programmable valve KV2A-1 to regenerate the water adsorbed in the alumina.

⑶ Oxygen-rich gas replacement P

After the series replacement P1 step is completed, close the program-controlled valves KV5D-1, KV3D-1 and KV2A-1, open the program-controlled valves KV5A-1 and KV3A-1, part of the oxygen-enriched gas evacuated in this section and the second pressure swing adsorption section After mixing, the desorption gas from the bottom of the adsorption tower T0101A enters the adsorbent bed to replace nitrogen and argon, and then flows out from the top. The replacement tail gas from the top enters from the bottom of the adsorption tower T0101B, and passes through the adsorption tower T0101B adsorbent bed to adsorb oxygen. , Through the programmable valve KV2B-1, return to the drying section to regenerate the water adsorbed in the alumina.

⑷Vacuum VC

The second pressure swing adsorption section

⑴Adsorption A

⑵E1D reduction

⑶ Reduce both E2D

⑷Reverse release BD

⑸E2R is up to two

⑹ One E1R

⑺Final boost FR

Claims

A method for a mobile pressure swing adsorption oxygen production device, which is characterized in that the method includes a first pressure swing adsorption section and a second pressure swing adsorption section operated in series, and the dried raw material air is in the first pressure swing adsorption section The adsorption tower passes through the speed-selective adsorbent bed, most of the oxygen in the raw air is adsorbed by the speed-selective adsorbent bed, most of the nitrogen and argon are discharged from the outlet of the adsorption tower, and the first pressure swing adsorption stage resolves The oxygen-rich mixed gas enters the nitrogen balance selective adsorbent bed of the adsorption tower of the second pressure swing adsorption section. The nitrogen in the oxygen-rich mixed gas is adsorbed by the nitrogen balance selective adsorbent bed, and oxygen, argon and a small amount of nitrogen are removed The outlet of the adsorption tower flows out; the adsorption tower of the first pressure swing adsorption section undergoes at least four pressure swing adsorption process steps in one cycle: adsorption A, series displacement P1, oxygen-rich displacement P, and vacuum VC; the second pressure swing adsorption The adsorption tower of the stage at least successively undergoes the adsorption A, equal pressure drop ED, reverse discharge BD or vacuum VC, equal pressure rise ER and product gas pressure rise FR pressure swing adsorption process steps in one cycle.
The method for a mobile PSA oxygen production device according to claim 1, wherein the adsorption tower of the second PSA section adds a PP step after the equalizing pressure drop ED step, and after the reverse discharge step BD The purge P step is added, and the gas of the PP step enters the buffer tank V in sequence, and the gas of the purge P step comes from the buffer tank V and enters from the top of the adsorption tower.
The method for a mobile PSA oxygen production device according to claim 1 or 2, characterized in that the bottom of the adsorption tower of the first PSA section is filled with desiccant, and the upper part of the bed of the adsorbent with selective filling speed contains gaseous When the raw material air of water passes through the bottom of the adsorption tower of the first pressure swing adsorption section, most of its gaseous water is adsorbed by the desiccant bed, and most of the oxygen is adsorbed by the speed selective adsorbent bed, and most of the nitrogen and argon are absorbed from the bed. The outlet of the adsorption tower is discharged, and the gaseous water and oxygen-enriched gas desorbed from the first pressure swing adsorption section enter the desiccant bed and nitrogen balance selective adsorbent bed from the bottom of the second pressure swing adsorption section of the adsorption tower, and the oxygen-rich mixed gas Most of the gaseous water is adsorbed by the desiccant bed, most of the nitrogen is adsorbed by the nitrogen balance selective adsorbent bed, and oxygen, argon and a small amount of nitrogen flow out from the outlet of the adsorption tower.
The method for a mobile pressure swing adsorption oxygen production device according to any one of claims 1 to 3, wherein the pressure of the adsorption step A of the adsorption tower of the first pressure swing adsorption section is 0.002-0.01 MPa (gauge pressure); The pressure of the adsorption step A in the adsorption tower of the second pressure swing adsorption section is 0.8-1.2 MPa (gauge pressure).
The method for a mobile PSA oxygen production device according to any one of claims 1 to 4, wherein the concentration of oxygen in the outlet gas at the end of the adsorption step A of the adsorption tower of the first PSA section is 15-20 %(V).
The method for a mobile pressure swing adsorption oxygen production device according to any one of claims 1 to 3, wherein the adsorption tower of the first pressure swing adsorption section is filled with carbon molecular sieve as the speed selective adsorbent; the second pressure swing adsorption The adsorption tower of the section is packed with 5A type molecular sieve or X type lithium molecular sieve as nitrogen balance selective adsorbent.
The method of a mobile pressure swing adsorption oxygen production device according to claim 1 or 2, wherein a pressure swing adsorption drying section is provided before the first pressure swing adsorption section for removing gaseous water in the raw air to achieve The moisture requirements of the adsorption tower entering the first pressure swing adsorption section; the pressure swing adsorption drying section undergoes at least two pressure swing adsorption process steps of adsorption A and purge P in one cycle, and the gas source of step P is purged The adsorption tower in the first pressure swing adsorption section adsorbs the vent air from the outlet of step A and the desorption air from the adsorption tower in the second pressure swing adsorption section.
The method for a mobile PSA oxygen production device according to claim 7, wherein the drying section is filled with activated alumina as the desiccant; the adsorption tower of the first PSA section is filled with carbon molecular sieve as the speed selective adsorption The inside of the adsorption tower of the second pressure swing adsorption section is filled with 5A type molecular sieve or X type lithium molecular sieve as nitrogen balance selective adsorbent.