JPH05184851A - Method for producing stream of oxygen rich product - Google Patents

Abstract

PURPOSE: To obtain a two bed pressure swing adsorption process having a high yield and a high production rate and to save driving power by utilizing fine or normal size zeolite sieve material and relatively short cycle times and sequencing the various steps of the process to provide substantially continuous use of a vacuum pump. CONSTITUTION: A process is operated in six steps as a whole for each complete cycle. In steps 1-3, a first column A is continuously evacuated with a vacuum pump 16, and in steps 4-6, a second column B is evacuated with the vacuum pump 16. Consequently the vacuum pump 16 is used throughout the complete cycle in this embodiment. In steps 1, 4 which are pressure equalization steps, a gas is introduced from a column under evacuation to another column. In steps 2, 5 a column which is not under evacuation receives a reversed charging gas from a product holder 18. In steps 3, 6 the column which is not under evacuation receives a feed gas to produce a product. The product gas is used to purge a column under evacuation.

Description

Detailed Description of the Invention

In the present invention, a mixed gas containing mainly oxygen and nitrogen as a gas component, for example, air, is used to transform an adsorption (pr).
(esure swing adoption)
(PSA) to obtain an oxygen-enriched gas.

Transformed adsorption systems and methods are widely used to produce oxygen-enriched streams from gas mixtures, including air, and many such systems and methods have been used.

In such systems, it is advantageous to use relatively short cycles to carry out the process, as long as the short time allows good utilization of the sieve material used for the adsorption of one of the components. is there. Short cycle times generally use finer grained sieve material to reduce diffusion resistance.
A typical example of a short cycle time is US Pat. No. 4,19.
4,891 and 4,194,892. Although the oxygen production increases according to the method of the above patent,
The yield is rather low, for example 10-20% yield.

The conventional vacuum PSA method has a high oxygen yield (5
However, the production rate is rather low. The production rate of the conventional 3-bed PSA process is not particularly high; for example, typically the bed size factor (bed size) is used.
factor) is about 2000-2600k zeolite
g / metric ton oxygen production / day.

Optimally, one obtains high yields typified by conventional three-bed systems with high cycle rates and high production rates exemplified by fine sieve particles, yet is inexpensive and operationally efficient. It is clearly desirable to have a relatively simple method.

The PSA method of the present invention minimizes cost and
By solving the drawbacks of the prior art while maintaining the simplicity of operation, an oxygen-enriched product is obtained with a high oxygen yield as well as a high production rate.

This system makes good use of the sieve material and uses short cycle times, but only requires two beds, and thus the prior art 3 which was previously required for high yields. Greatly simplifies the floor method.

As shown below, one of the other features is
Power savings due to continuous or near continuous use of the vacuum pump with the adsorption column system. This means that part or all of the pressure equalization operation is carried out, during which the oxygen-enriched stream from the outlet end of the first column is fed to the outlet end of the second column and the inlet end of the first column is fed. Is achieved by desorbing a nitrogen-enriched gas from the. By this means,
A vacuum pump operates during at least part of the pressure equalization operation as well as during the rest of the process. Since the vacuum pump operates continuously or almost continuously during the entire cycle, its use and thus its power consumption are optimized.

Therefore, it has a high yield and a high production rate.
The bed PSA method is used for less than 40 seconds, preferably with a relatively fine zeolite sieve material, for example 20-35 mesh size, and also with large particles, for example 8-12 mesh size, for less than 40 seconds. Perform for a short cycle time of 30 seconds. The range of pressure fluctuation is less than 300 torr for desorption, preferably 200
vacuum up to torr and less than 5 psig, preferably 3
Maximum product pressure below psig is used.

In a first embodiment of the invention, the process is carried out in a total of 6 steps for each complete cycle.
In steps 1 to 3, the first column is continuously evacuated by a vacuum pump, and in steps 4 to 6, the second column is evacuated by a vacuum pump. Therefore, in this embodiment, a vacuum pump is used throughout the cycle. In the pressure equalization steps, steps 1 and 4, gas is directed from the exhausting ram to the other column; in steps 2 and 5, the nonexhausting column receives backfill gas from the product sump; step 3 At and 6, the column not being evacuated receives the feed gas and produces product, which product gas is used to purge the column being evacuated.

In a second embodiment of the invention, the process is carried out in a total of 8 steps for each complete cycle.
In steps 1 to 4, the first column is continuously evacuated by a vacuum pump, and in steps 5 to 8, the second column is continuously evacuated by a vacuum pump. Therefore, in this embodiment, a vacuum pump is used throughout the cycle. In the pressure equalization steps, steps 1 and 5, gas is directed from the column being evacuated to the other column; in steps 2 and 6, the column not being evacuated receives backfill gas from the product sump; step 3 At and 7, the non-evacuated column receives the feed gas and produces the product; at steps 4 and 8, the non-evacuated column receives the feed gas and continues to produce the product,
The product gas is used to purge the column during evacuation. In other words, the cycle of this embodiment is the same as the first embodiment, except that the column that is not evacuated in this embodiment produces the product and the other column is evacuated without purging. The cycle of this embodiment is more efficient than the cycle of the first embodiment.

In a third embodiment of the invention, the process is carried out in a total of 10 steps for each complete cycle. In steps 2-5, the first column is continuously evacuated by a vacuum pump, and in steps 7-10, the second column is continuously evacuated by a vacuum pump. Therefore, in this embodiment, a vacuum pump is used throughout 8 out of 10 steps of the operating cycle. In steps 1 and 6 that are pressure equalization steps, gas is introduced from the column that has just finished production to the other column; in steps 2 and 7 that are also pressure equalization steps, gas is discharged from the column being evacuated to the other column. In steps 3 and 8, the non-venting column receives backfill gas from the product sump; in steps 4 and 9, the non-venting column receives feed gas to produce product. ;
In steps 5 and 10, the column, which is not evacuating, receives the feed gas and continues to produce product, which product gas is used to purge the column during evacuation. Therefore, the cycle of this embodiment is the same as the cycle of the second embodiment, except that this embodiment includes a pressure equalization step without exhaust. The advantage of this embodiment is that there is less disturbance of the bed supplying the gas during the pressure equalization operation, which means that this bed has a maximum differential pressure between the two beds during the initial part of the pressure equalization operation. This is because the pressure is not reduced from both ends at one time.

FIG. 1 is a schematic flow chart of the present invention; FIG. 2 illustrates a column cycle of the first embodiment of the present invention;
Illustrates the column cycle of the second embodiment of the present invention; FIG. 4 illustrates the column cycle of the third embodiment of the present invention.

The cycle of the first embodiment of the present invention will be described in detail with reference to the schematic flow chart shown in FIG. 1 and the column cycle shown in FIG.

Initially, FIGS. 1 and 2 show a system for producing a continuously generated oxygen-enriched gas stream from a gas containing mainly oxygen and nitrogen, such as air. Each of the two adsorption columns A and B contains an adsorbent capable of selectively adsorbing nitrogen.

In all process embodiments of the present invention, the adsorption column is packed with relatively particulate, ie, about 8-35 mesh, preferably about 12-20 mesh zeolite. Typical zeolite sieve materials are available as beads or pellets from various zeolite manufacturers. Control of each step of the process embodiment is adjusted by conventional means, such as a timer to control a standard commercial design solenoid operated valve.

In step 1 of the first embodiment (shown in FIG. 2), the lower or inlet end of the first column A is closed by closing valves 1A and 2A. At the upper end of column A, the outlet end, valves 4A and 5A are closed and valve 3A
open. For the second column B, close valves 9B and 10B; thus gas from the outlet of column B is introduced into the outlet of column A through valve 3A, this flow being controlled by valve 8B. At the same time, in step 1, valve 6B is closed at the inlet end of column B, but valve 7B is open; therefore gas is drawn from the inlet end of column B by vacuum pump 16.

During this step, the pressure in the column B is initially higher than the pressure in the column A to make the pressures in both columns substantially equal. That is, column B is step 1
At the beginning of about 1010 torr (4.84 psi)
g) positive pressure, but about 500t by the end of step 1
Column A begins Step 1 at a pressure of about 200 torr (-10.83 psig) and boosts pressure to 470 torr (-5.61 psig). Therefore, at the end of step 1, the column pressures are essentially equal. Step 1 is performed very rapidly, preferably in about 2-6 seconds, more preferably in about 4 seconds.

In step 2, valve 3A closes and valves 5A and 24
Opens and the oxygen-enriched product gas from sump 18 is in column A.
At the outlet of the column and controlled by metering valve 26 to backfill column A and further increase column A pressure. Typically, the pressure in the product sump is about 800 torr, so the pressure in column A is 470 torr (-5.61).
psig) to about 660 torr (-1.93 psi)
Continue to rise to g). At the same time, the gas is still drawn by the vacuum pump 16 from the outlet of column B through the open valve 7B and the pressure in column B continues to drop. This pressure is 500 torr (-5.03 psi) in step 2.
g) to about 450 torr (-6.00 psig). The time of step 2 is also very fast, preferably about 1 to 5 seconds, more preferably about 3 seconds.

In step 3, the valve 1A is opened and air or other feed gas containing mainly oxygen and nitrogen is introduced into the inlet of column A through line 14 under a given feed pressure.
The inlet pressure can fluctuate, but ideally the inlet pressure is 3-7.
have a minimum predetermined pressure of psig, more preferably about 5p
has a minimum value of sig. At the outlet of column A, valve 5A
Closes and valve 4A opens. Therefore, the supply air passes through the column A, the nitrogen is adsorbed in the column A, the oxygen-enriched product stream exits the outlet end of the column A, the valve 4A, the check valve 11
To the product sump 18 through line 20.
During this step, the pressure in column A varies from 660 torr (-1.93 psig) to 101 during production of the oxygen-enriched product.
Rise to 0 torr (4.84 psig). At the same time, in step 3, the gas is continuously drawn from the inlet end of the column B, and the nitrogen-enriched gas is desorbed or exhausted from the column B by the vacuum pump 16. Simultaneous with the desorption of column B from its inlet, valves 10B and 24 open and an oxygen-enriched product stream is introduced at the outlet of column B to purge column B. The flow of oxygen-enriched product stream is controlled by metering valve 26. Thus, column B is purged by the oxygen-enriched gas stream introduced at its outlet and desorbed by withdrawing nitrogen-enriched gas from its inlet. Therefore, the pressure in column B is typically about 450 torr when the withdrawal by vacuum pump 16 continues unhindered.
(-6.10 psig) to about 200 torr (-1
Continues to drop to 0.83 psig). Step 3 is also performed very rapidly, preferably in about 10-25 seconds, more preferably about 18 seconds.

Continuing to step 4, equalization is carried out again, this time by introducing the now high pressure gas of column A into column B. This is done by closing valve 4A at the outlet of column A and opening valve 3A. At the outlet of column B, valve 10B is closed and the gas is controlled by metering valve 8B to reach column B from column A for pressure equalization. At the same time, of course, the feed flow is shut off by closing valve 1A at the inlet of column A, and when valve 2A is opened, gas is drawn from the inlet end of column A by vacuum pump 16. The inlet of column B is completely closed by closing valve 7B.

Therefore, in step 4, the pressures in column A and column B become approximately equal, and the pressure in column A is about 1
About 500 tons from 010 torr (4.84 psig)
The pressure in column B rises from about 200 torr (-10.83 psig) to about 470 torr (-5.61 psig). Step 4 is preferably performed within a time period of about 2 to about 6 seconds, more preferably about 4 seconds.

In step 5, valve 3A is closed to completely close the outlet end of column A and gas continues to be drawn from the inlet end of column A at a pressure of typically 500 torr.
(-5.03 psig) to 450 torr (-6.0)
0 psig). Valves 10B and 28 are opened and oxygen enriched product from product reservoir 18 enters column B,
Column B pressure is typically about 470 torr (-5.6 torr).
1 psig to about 660 torr (-1.93 psi)
Backfill the column, controlled by metering valve 30 to rise to g). Again, as in step 2,
The backfilling step is performed for about 1-5 seconds, preferably about 3 seconds.

Finally, in step 6, valve 6B is opened and the compressed feed stream is introduced at the inlet of column B. When valve 9B opens,
The oxygen-enriched product stream from column B passes through check valve 12 and reaches product sump 18 via line 20.

In step 6, valves 24 and 5A are opened so that the oxygen-enriched gas enters the outlet of column A controlled by metering valve 26 to purge column A. Column A
Simultaneously with the purging, the gas is drawn from the inlet of the column A by the vacuum pump 16 to continue to desorb or exhaust the nitrogen-enriched gas. Typically, again in this case, the pressure in column A drops from about 450 torr (-6.00 psig) to about 200 torr (-10.83 psig),
The pressure in column B is about 660 torr (-1.93 ps).
ig) to about 1010 torr (4.84 psig). The time of step 6 is about 10 to about 25 seconds, preferably about 18 seconds.

At the end of step 6, the entire process sequence is repeated on a continuous cycle basis, with product being continuously removed from product sump 18 through valve 32 during each process.

As can be seen, in this embodiment,
The vacuum pump 16 is used continuously to withdraw gas alternately from either of the two columns, thus effectively utilizing the vacuum pump and minimizing power usage throughout the entire cycle.

Next, referring to FIG. 3, FIG. 3 shows a modification of the basic cycle shown in FIG. Steps 1, 2, 5 and 6 of the cycle of FIG. 3 are the same as steps 1, 2, 4 and 5 of the cycle of FIG. 2, respectively. Figure 3 Process 3 of the cycle
Is the same as step 3 of FIG. 2 cycle, but step 3 of FIG.
Column B is not purged with product gas therein. Similarly, step 7 of FIG. 3 cycle differs from step 6 of FIG. 2 cycle by not purging column A during step 7 of FIG. 3 cycle. This result occurs by keeping valves 10B and 24 closed during step 3 of the FIG. 3 cycle and keeping valves 5A and 24 closed during step 7.

Therefore, in step 3 of the cycle shown in FIG.
A is opened, and air or other feed gas containing mainly oxygen and nitrogen is introduced into the inlet of the column A under a predetermined feed pressure. Inlet pressure can vary, but ideally 3-7 psi
It has a predetermined minimum value of g, and preferably has a minimum value of about 5 psig. At the outlet of column A, valve 5A is closed and valve 4
A opens. The feed air passes through column A where nitrogen is adsorbed and the oxygen-enriched product stream exits the outlet end of column A through valve 4A, check valve 11 and line 20 Reach sump 18. During this step, the pressure in column A was about 660 torr during the production of the oxygen-enriched product.
(-1.93 psig) to about 900 torr (2.7
1 psig). In step 3, the gas is continuously extracted from the inlet end of the column B, and the nitrogen-enriched gas is desorbed or exhausted from the column B by the vacuum pump 16.
Thus, the pressure in column B will typically be about 450 as the withdrawal by vacuum pump 16 continues unimpeded.
Approximately 210 torr from torr (-6.00 psig)
Continues to drop to (-10.64 psig). Step 3 is carried out very rapidly, preferably within a cycle time range of about 8 to 20 seconds, more preferably about 13 seconds.

Similarly, in step 7 of the cycle shown in FIG.
B is opened and feed gas is introduced into column A through its inlet. At the outlet of column B, when valve 9B is opened, the oxygen-enriched product stream from column B is checked valve 12, line 20.
The product reservoir 18 is reached via During step 7, the pressure in column A was approximately 450 torr (-6.00 psig).
To about 210 torr (-10.64 psig), the pressure in column B is about 660 torr (-1.9 torr).
3 psig to about 900 torr (2.71 psi)
up to g). Step 7 takes about 8 to about 20 seconds,
It is preferably about 13 seconds.

The steps 4 and 8 of the cycle of FIG. 3 are the same as the steps 3 and 6 of the cycle of FIG. 2, but the duration of the steps 4 and 8 of the cycle of FIG. Is also short. Further, the initial pressure of the column exhausted in steps 4 and 8 of the cycle of FIG.
Due to the continued evacuation of the adsorbent at 7 and 7, it is lower than the initial pressure of the column being evacuated at steps 3 and 6 of the FIG.

Therefore, in step 4 of the cycle shown in FIG.
A and 4A open, whereby the oxygen-enriched product stream produced in column A enters product sump 18 through check valve 11 and line 20, and in step 8, valves 6B and 9B open. Thereby, the oxygen-enriched product stream produced in column B reaches the product sump 18 through the check valve 11 and the line 20. In step 4, the valves 7B, 10B,
24 opens so that the oxygen-enriched gas can purge column B and vacuum pump 16 can continue to evacuate column B. During step 8, valves 2A, 5A, 2
4 is also opened so that the oxygen-enriched gas can purge column A and vacuum pump 16 can continue to evacuate column A.

In step 4, the pressure in column B is about 210.
About 200 torr from torr (-10.64 psig)
r (-1.83 psig) and the pressure in column A is about 900 torr (2.71 psig) to about 1
Rise to 010 torr (4.84 psig). Similarly, in step 8, the pressure in column A is about 210 torr.
From r (-10.64 psig) to about 200 torr (-
10.83 psig) and the pressure in column B is about 900 torr (2.71 psig) to about 1010
Rise to torr (4.84 psig). The time of steps 4 and 8 is about 5 to about 15 seconds, preferably about 10 seconds.

From the above, it can be seen that the total cycle time for this embodiment is typically in the range of about 16 to about 46 seconds. In a preferred embodiment, the total time of the 8-step cycle is less than about 40 seconds, most preferably about 30 seconds.

Also in this embodiment, the vacuum pump 16 is used effectively to continuously use the vacuum pump 16 to alternately draw gas from either of the two columns to minimize power usage throughout the cycle. ..

Next, referring to FIG. 4, FIG. 4 shows a modification of the basic cycle shown in FIG. Steps 3, 4, 5, 8, 9 and 10 of the cycle of FIG. 4 are the same as steps 2, 3, 4, 6, 7 and 8 of the cycle of FIG. 3, respectively.
The step 1 in FIG. 4 cycle is the same as the step 1 in FIG. 3 cycle because the column B is not exhausted in the step 1 in FIG. 4 cycle.
different. Similarly, step 6 of FIG. 4 cycle is different from step 5 of FIG. 3 cycle in that column A is not evacuated in step 6 of FIG. 4 cycle. This result occurs by keeping valve 7B closed in step 1 of the FIG. 4 cycle and keeping valve 2A closed in step 6 of the FIG. 4 cycle. Steps 2 and 7 of the FIG. 4 cycle differ from steps 1 and 5 of the FIG. 3 cycle only by the duration of these steps and the pressure at the beginning of these steps not being the same.

In step 1 of the cycle shown in FIG. 4, the valve 3A is opened and all the other valves (except the valve 32) are closed. During this process, gas reaches column A from column B. During this step, the pressure in column A is typically about 200 torr (-10.83 psig) to about 400 torr (-6.9).
6 psig) and the pressure in column B is about 101
0 torr (4.84 psig) to about 750 torr
(-0.19 psig). Step 1 is carried out very rapidly, preferably within a cycle time range of about 2-6 seconds, more preferably within a cycle time range of about 4 seconds.

Similarly, in step 6 of the cycle shown in FIG.
A opens and all other valves (except valve 32) close. During this step, gas reaches column B from column A and the pressure in column B is typically about 200 torr (-10.83).
psig) to about 400 torr (-6.96 psi)
g), the pressure in column A is about 1010 torr
r (4.84 psig) to about 750 torr (-0.
19 psig). Step 6 is likewise preferably carried out within a cycle time range of about 2 to 6 seconds, more preferably within a cycle time range of about 4 seconds.

Steps 2 and 7 of the FIG. 4 cycle are the same as steps 1 and 5 of the FIG. 3 cycle, except that step 2 of the FIG. 4 cycle is
And 7 are shorter than the preferred duration of steps 1 and 5 of FIG. 3 cycle, and the initial column pressure evacuated in steps 2 and 7 of FIG. 4 cycle is
The initial pressure of the column exhausted in steps 1 and 5 of the cycle in FIG. 3 is lower because the gas is transferred from the column that has just finished production to the column that has just finished regeneration.

In Step 1 of the cycle shown in FIG. 4, the pressure in the column B is lowered from about 1010 torr (4.84 psig) to about 750 torr (-0.19 psig), and the pressure in the column A is about 200 torr (-10.83 ps).
ig) to about 400 torr (-6.96 psig). Similarly, in step 6, the pressure in column A is from about 1010 torr (4.84 psig) to about 750.
down to torr (-0.19 psig), column B
The internal pressure is about 200 torr (-10.83 psig)
To about 400 torr (-6.96 psig). The time of steps 1 and 6 is about 2 to 6 seconds, preferably about 4 seconds.

In Step 2 of the cycle shown in FIG. 4, the pressure in the column B is lowered from about 750 torr (-0.19 psig) to about 500 torr (-5.03 psig), and the pressure in the column A is about 400 torr (-6. 96 psi
g) to about 470 torr (-5.61 psig). Similarly, in step 7, the pressure in column A is about 750 torr (-0.19 psig) to about 500 t.
The pressure in column B rises from about 400 torr (-6.96 psig) to about 470 torr (-5.61 psig). The time for steps 2 and 7 is about 1-5 seconds, preferably about 3 seconds.
Seconds.

In this embodiment, vacuum pump 16 is continuously used to withdraw gas alternately from either of the two columns in eight of the ten steps of the cycle. Therefore, vacuum pumps are effectively used to minimize power usage throughout most of the cycle. In processes where the vacuum pump is not used to pump the column, the vacuum pump optionally continues to operate by supplying air to the pump.

From the above, it can be seen that the total cycle time for this embodiment is typically in the range of about 17 to about 51 seconds. In a preferred embodiment, the total time for a 10 step cycle is less than about 40 seconds, ideally about 30 seconds.

The invention will be further described by the following examples, in which the middle part,% and ratios, unless otherwise indicated,
It is based on the volume.

Example 1 Using the apparatus shown in FIG. 1 and the process sequence shown in FIG. 2, the method of the present invention was carried out to obtain an oxygen-enriched product stream. For 2 adsorption columns A and B (2 inch diameter and 15 inch height respectively) and for runs 1-3 (Table 1) 0.4 commercially available from Laporte Co. ~ Calcium X zeolite molecular sieve material as 0.8mm beads and Zeolite material (Tos as 1.5mm pellets from Tosoh Company for Run 4).
oh Zeolum SA). The pressure fluctuation range during the cycle was 3.5 psig to 200 torr.

The cycle times, production rates and yields obtained are summarized in Table 1.

Table 1 Run 1 2 3 4 Cycle time (sec) 25 20 17 25 Oxygen purity (%) 93 93 93 93 93 Bulk density (kg / cm ³ ) 681 681 681 620 Oxygen yield (%) 59 58 56 55 Specific production (Production oxygen standard liter / hour 40 51 59 40 / liter bed) Bed size factor (zeolite kg 535 420 375 487 / ton oxygen / day) From the above test, continuously apply vacuum to any of the columns during each step. It can be seen that the high yield and high production rate in high purity can be achieved by the two column system applied to. Therefore,
Vacuum pumps are used effectively, saving power. The cycle is very fast, the sheaves are well utilized, the two-bed system is more complex in construction and operation, and a clear advantage over the more costly three-bed system.

Example 2 The process of the present invention was carried out using the apparatus shown in FIG. 1 and the process sequence shown in FIG. 3 to obtain an oxygen-enriched product stream. Adsorption columns A and B were 24 inches in diameter and 4 feet long. The column was filled with 25-inch Tosoh SA sieve and 6-inch alumina, and alumina was placed at the inlet end of the column to adsorb water. The run duration was sufficient to reach steady state.

The cycle times, production rates and yields obtained are summarized in Table 2.

Table 2 Process duration, seconds 1 and 5 4 2 and 6 3 3 3 and 7 13 4 and 8 10 Total cycle time 30 Product purity (oxygen%) 93.1 Yield (%) 44.7 Specific production (Product Nm ³ / hr / m ³ sieve) 40.1 As shown in Table 2, high product purity and good yields are obtained using the cycle of this embodiment of the invention.

Example 3 The process of the present invention was carried out using the apparatus shown in FIG. 1 and the process sequence shown in FIG. 4 to obtain an oxygen-enriched product stream. Adsorption columns A and B have a diameter of 4.3 cm and a length of 1.8 m
Met. Tosoh SA up to a height of about 1.7 m on the column
Filled with 500 sieves. In this example, about 30 cm
A pre-guard bed packed with alumina was used for each column for moisture absorption. The top of the adsorbent bed was sprayed with paint prior to the experiment to see if the bed fluctuated during the cycle. The floor surface was examined after the end of the experiment to see if the paint layer was complete. The disturbed surface demonstrates floor variation.

The cycle times, production rates and yields obtained are summarized in Table 2.

Table 3 Process duration, sec 1 and 6 4 2 and 7 3 3 and 8 3 4 and 9 10 5 and 10 10 Total cycle time 30 Product purity (oxygen%) 93 Yield (%) 49.2 Specific production (product Nm ³ / hr / m ³ sieve) 41 As can be seen from the table above, good performance results were obtained.
The surface of the bed was examined and found to be undisturbed, demonstrating no migration of the adsorbent bed. Process 1
Floor variations were detected when the same test was performed without and. Therefore, the 10-step cycle of the present invention is even more advantageous.

While particular embodiments of the present invention have been shown, it should be understood that the invention is not limited thereto, as modifications may be made, and that the invention includes modifications that fall within the scope of the claims. Be interpreted as

[Brief description of drawings]

FIG. 1 is a schematic flow chart of the present invention.

FIG. 2 illustrates a column cycle according to the first embodiment of the present invention.

FIG. 3 illustrates a column cycle according to a second embodiment of the present invention.

FIG. 4 illustrates a column cycle according to a third embodiment of the present invention.

[Explanation of symbols]

 A. Adsorption column B. Adsorption column 16. Vacuum pump 18. Product reservoir

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[Procedure amendment]

[Submission date] October 6, 1992

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

[Figure 3]

[Figure 1]

[Fig. 2]

[Figure 4]

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Claims (25)

[Claims] 1. A method for producing an oxygen-enriched product stream from a feed gas containing at least oxygen and nitrogen using two adsorption columns containing an adsorbent capable of selectively adsorbing nitrogen and a product reservoir. And the following steps: (i) introducing gas from the outlet of the high-pressure second adsorption column to the outlet of the low-pressure first adsorption column while drawing the gas from the inlet of the second adsorption column to substantially reduce the pressure in both columns. (Ii) after the pressure equalization step of step (i), while continuing to draw gas from the inlet of the second adsorption column, the product gas contained in the high-pressure product reservoir is discharged from the outlet of the first column. Introduced to
Backfilling the first column; (iii) introducing the feed gas into the inlet of the first column at a predetermined pressure, recovering the product of the oxygen-enriched gas from the outlet of the first column, and adding the oxygen-enriched stream. Is introduced into the product reservoir, a part of the product stream is introduced into the outlet of the second column, the second column is purged, and at the same time, gas is drawn out from the inlet of the second column and enriched with nitrogen from the second column. A step of desorbing and exhausting the gas; (iv) while introducing the gas from the inlet of the first column, initially introducing the gas from the outlet of the high pressure first column to the outlet of the second column, (V) after the pressure equalizing step of (iv), the oxygen-enriched product gas contained in the high-pressure product reservoir while continuing to draw gas from the inlet of the first adsorption column Is introduced into the outlet of the second column; and (vi The feed gas is introduced at the predetermined pressure to the inlet of the second column, and recovering the product of the oxygen-enriched gas from the outlet of the second column, is introduced into product reservoir the oxygen-enriched stream,
Introducing part of the product stream into the outlet of the first column to purge the first column, at the same time withdrawing gas from the inlet of the first column to desorb and exhaust the nitrogen enriched gas from the first column And withdrawing oxygen-enriched product gas from the product reservoir,
The method wherein the steps (i) to (vi) are cyclically repeated. 2. The method of claim 1 wherein the feed gas is air at a pressure of about 3 to about 7 psig and the adsorbent is about 8-35 mesh zeolite. 3. The method of claim 2, wherein the zeolite is in the form of beads or pellets having a size of about 12 to about 20 mesh. 4. The steps (i) and (iv) are carried out for about 2 to 6 seconds; the steps (ii) and (v) are carried out for about 1 to 5 seconds; the steps (iii) and ( The method of claim 1, wherein vi) and are performed for about 10 to 25 seconds. 5. The steps (i) and (iv) are performed for about 4 seconds; the steps (ii) and (v) are performed for about 3 seconds; and the steps (iii) and (vi) are performed. The method of claim 4, wherein the method is performed for about 18 seconds. 6. The steps (i) and (iv) include equalizing the pressure in both columns to about 470 to about 500 torr; the product gas in steps (ii) and (v) being about 8
The method of claim 1 wherein the feed gas is introduced at a pressure of 00 torr; and the feed gas is introduced at a pressure of about 3-7 psig in steps (iii) and (vi). 7. The method of claim 6, wherein the feed gas is at a pressure less than about 5 psig. 8. The steps (i) to (vi) are about 40.
The method of claim 1, wherein the method is performed in less than a second. 9. A method for producing an oxygen-enriched product stream from a feed gas containing at least oxygen and nitrogen using two adsorption columns containing an adsorbent capable of selectively adsorbing nitrogen and a product reservoir. And the following steps: (i) introducing gas from the outlet of the high-pressure second adsorption column to the outlet of the low-pressure first adsorption column while drawing the gas from the inlet of the second adsorption column to substantially reduce the pressure in both columns. (Ii) after the pressure equalization step of step (i), while continuing to draw gas from the inlet of the second column, the product gas contained in the high pressure product reservoir is discharged to the outlet of the first column. Introduced, first
Backfilling the column; (iii) introducing a feed gas into the inlet of the first column at a predetermined pressure, withdrawing an oxygen-enriched gas stream from the outlet of the first column, the oxygen-enriched stream in the product sump. A step of recovering and at the same time drawing gas from the inlet of the second column to desorb the nitrogen-enriched gas from the second column and exhausting; (iv) introducing the feed gas into the inlet of the first column at a predetermined pressure, An oxygen-enriched gas stream is drawn from the outlet of one column and the oxygen-enriched stream is recovered in a product reservoir, at the same time a gas is drawn from the inlet of the second column to desorb the nitrogen-enriched gas from the second column. A step of introducing a part of the product stream into the outlet of the second column while continuing to exhaust the gas and purging the second column; From the outlet of one column to the second column A step of introducing gas into the mouth to make the pressures in both columns substantially equal; (vi) after the pressure equalization in step (v), while continuing to draw gas from the inlet of the first column, a high-pressure product reservoir Introducing the oxygen-enriched product stream contained therein into the outlet of the second column; (vii) introducing the feed gas into the inlet of the second column at a predetermined pressure, and flowing the oxygen-enriched gas stream from the outlet of the second column. Withdrawing, recovering the oxygen-enriched stream in a product reservoir, at the same time withdrawing gas from the inlet of the first column to desorb and exhaust the nitrogen-enriched gas from the first column; and (viii) supply Gas is introduced into the inlet of the second column at the predetermined pressure, an oxygen-enriched stream is withdrawn from the outlet of the second column, oxygen-enriched gas is recovered in the product reservoir, and at the same time gas is introduced from the inlet of the first column. Pull out and nitrogen rich from the second column Gas is desorbed, while evacuating, introducing a part of the product stream to the outlet of the first column includes the step of purging the first column, while pulling the oxygen-enriched product gas from the reservoir products,
The above method, wherein steps (i) to (viii) are periodically repeated. 10. The method of claim 9 wherein said feed gas is air at a pressure of about 3 to about 7 psig and said adsorbent is about 8-35 mesh zeolite. 11. The method of claim 11, wherein the zeolite is in the form of beads or pellets having a size of about 12 to about 20 mesh. 12. The steps (i) and (v) are carried out for about 2 to 6 seconds; the steps (ii) and (vi) are carried out for about 1 to 5 seconds; and the steps (iii) and ( 10. The method of claim 9, wherein vii) is performed for about 8-20 seconds; steps (iv) and (viii) are performed for about 5-15 seconds. 13. The steps (i) and (v) are performed for about 4 seconds; the steps (ii) and (vi) are performed for about 3 seconds; the steps (iii) and (vii) are performed. 13. The method of claim 12, wherein said steps (iv) and (viii) are performed for about 3 seconds; about 10 seconds. 14. The method of claim 13, wherein the feed gas is at a pressure less than about 5 psig. 15. The method of claim 9, wherein steps (i) through (viii) are performed in less than about 40 seconds. 16. A method for producing an oxygen-enriched product stream from a feed gas containing at least oxygen and nitrogen using two adsorption columns containing an adsorbent capable of selectively adsorbing nitrogen and a product reservoir. The following steps: (i) introducing gas from the outlet of the high pressure second adsorption column to the outlet of the low pressure first adsorption column; (ii) from the outlet of the second adsorption column to the outlet of the first adsorption column The step of continuously introducing the gas until the pressures in both columns become substantially equal, and simultaneously withdrawing the gas from the inlet of the second column; (iii) after the pressure equalization in step (ii), Introducing the product gas contained in the high-pressure product reservoir into the outlet of the first column while continuing to draw gas from the inlet to backfill the first column; (iv) feed gas of the first column Introduced at a predetermined pressure at the inlet, Withdrawing an oxygen-enriched gas stream from the outlet of the column, collecting said oxygen-enriched stream in the product reservoir, at the same time withdrawing gas from the inlet of the second column to desorb the nitrogen-enriched gas from the second column, Exhausting step; (v) introducing a feed gas into the inlet of the first column at the predetermined pressure, withdrawing an oxygen-enriched gas stream from the outlet of the first column, and recovering the oxygen-enriched stream into the product reservoir. , Second
Withdrawing gas from the inlet of the column to desorb the nitrogen-enriched gas from the second column and, while continuing to exhaust, introduce a portion of the product stream to the outlet of the second column to purge the second column; (Vi) introducing gas from the outlet of the high pressure first adsorption column to the outlet of the low pressure second adsorption column; (vii) from the outlet of the first adsorption column to the outlet of the second adsorption column, Continuously introducing gas from the inlet of the first column while continuing to introduce gas until the pressures become substantially equal; (viii) Continue to withdraw gas from the inlet of the first column after the pressure equalization in step (vii) While introducing the oxygen-enriched product gas contained in the high pressure product reservoir into the outlet of the second column; (ix) introducing the feed gas into the inlet of the second column at a predetermined pressure, Pull the oxygen-enriched stream from the outlet And,
Recovering the oxygen-enriched stream into a product sump, simultaneously withdrawing gas from the inlet of the first column to desorb and exhaust the nitrogen-enriched gas from the first column; and (x) feed gas Introduced at the predetermined pressure at the inlet of the second column, withdrawing an oxygen-enriched stream from the outlet of the second column, collecting oxygen-enriched gas in the product reservoir, and withdrawing gas from the inlet of the first column. , Desorbing the nitrogen-enriched gas from the first column and introducing a part of the product stream into the outlet of the first column while continuously exhausting the gas, and purging the first column. While drawing out the chemical product gas,
The above method, wherein steps (i) to (x) are cyclically repeated. 17. The method of claim 16 wherein the feed gas is air at a pressure of about 3 to about 7 psig and the adsorbent is about 8-35 mesh zeolite. 18. The method of claim 17, wherein the zeolite is in the form of beads or pellets having a size of about 12 to about 20 mesh. 19. The steps (i) and (vi) are about 2 to 6
Step (ii) and (vii) for about 1 to 5 seconds; steps (iii) and (viii) for about 1 to 5 seconds; steps (iv) and (ix) The method according to claim 16, wherein the steps (v) and (x) are performed for about 5 to 15 seconds. 20. The steps (i) and (vi) are carried out for about 4 seconds; the steps (ii) and (vii) are carried out for about 3 seconds; the steps (iii) and (viii) are carried out. About 3 seconds;
20. The method of claim 19, wherein steps (iv) and (ix) are performed for about 10 seconds; steps (v) and (x) are performed for about 10 seconds. 21. The method of claim 20, wherein the feed gas is at a pressure of about 5 psig. 22. The steps (i) to (x) are about 40.
17. The method of claim 16 performed in less than a second. 23. In a system for carrying out a continuous production of an oxygen-enriched gas stream from a feed stream of air, the following elements: (a) each having an inlet and an outlet and containing an adsorbent for adsorbing nitrogen, each comprising: Programmed to work in different phases, one adsorption zone has a sequence of steps consisting of pressure boost equalization, backfill, production, and the other adsorption zone is synchronized with the pressure reduction equalization, exhaust, purge. A pair of adsorption zones having a sequence of steps consisting of: (b) oxygen-enriched gas storage means; (c) inlets of adsorption zones connected to the inlets of both adsorption zones for adsorption during the production process. (D) a gas supply means connected to the inlets of both of the adsorption zones, which includes a pipe and a vacuum pump, and which carries out step-down pressure equalization, exhaust and purge,
Evacuation means set to take out gas during these steps; (e) Connecting the outlets of both adsorption zones, including a pipe and a flow control valve, during the pressure equalization step of both adsorption zones Fluid communication means set to fluidly communicate between the outlets; (f) Backfilling, including pipes and flow control valves connecting the outlets of both adsorption zones to the oxygen-enriched gas storage means. First fluid communication means set to fluidly connect the adsorption zone and the oxygen-enriched gas storage means during the backfilling step; (g) the oxygen-enriched gas storage outlets of both adsorption zones Second fluid communication means including a tube and a flow control valve connected to the means, the second fluid communication means configured to connect the adsorption zone for purging and the oxygen-enriched gas storage means during the purging step; (H) Control for performing the setting process in (a) and (c) to (g). A system that includes means. 24. The apparatus of claim 23, wherein said adsorption column comprises about 8-35 mesh zeolitic material. 25. The method of claim 24, wherein the zeolitic material is in the form of beads or pellets having a particle size of 12-20 mesh.