JPH10225609A - Gas bulk separation by parametric gas chromatograph - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable alternatively taking out of oxygen and nitrogen from the end parts of outlets of adsorbers at fixed time intervals in two adsorbers by repeating the individual operation of raw material pressurizing, product transfer, concurrent flow pressure educing, purging. SOLUTION: Raw material air is pressurized and fed into an adsorber A, and oxygen-rich gas is taken out from the outlet end thereof and is concurrently fed into an adsorber B as purge gas. When pressure in the adsorber A reaches maximum operating pressure, the feeding of the raw material air is stopped and product oxygen is taken out. Next, an equalizing valve of the adsorber A is opened and the adsorber A and the adsorber B are concurrently connected to balance pressures of the two columns. Next, residual gas in the adsorber A is concurrently released in the air to make the pressure therein minimum operating pressure. And oxygen rich-gas is concurrently fed into the adsorber A from the outlet end of the adsorber B to purge nitrogen remaining in the adsorber A. In two-column constitution, the same operation is repeated by one cycle operation/two hours delay.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for bulk gas separation by parametric gas chromatography, and more particularly, to a method for separating easily adsorbable components (A) from easily adsorbed components (A) by, for example, separating and producing oxygen and nitrogen from air. The raw material mixed gas containing the component (B) is passed from the inlet end to the outlet end of the adsorbent column, and the hardly adsorbable component (A) and the easily adsorbable component (B) are separated and alternated at regular intervals from the outlet end. The present invention relates to a gas bulk separation method capable of separating and producing hardly adsorbable components (A) and easily adsorbable components (B) with low power consumption and high overall efficiency.

[0002]

2. Description of the Related Art At present, industrial production of oxygen and nitrogen is mainly performed by an air liquefaction separation method (abbreviated as a cryogenic method), and oxygen is mainly transferred to steel metallurgy by means of pipeline or liquid acid transportation. Nitrogen is supplied to and used in the electronics industry as an atmosphere gas for LSI production. In addition, a part of small and medium-scale applications is known as on-site pressure swing adsorption (PSA) from air.
Is used to separate oxygen and nitrogen, and supplied to the pipeline.

[0003] The cryogenic method is the only method at present capable of co-producing a large amount of high-purity oxygen and high-purity nitrogen, but has a problem in that the equipment configuration is complicated and the equipment price is expensive due to the use of high-grade materials. . This deep cooling method is a technology invented around 1900,
By 1955, the basics of industrial equipment had reached the level of completion, and even today, partial improvements such as improved efficiency of component equipment and machinery, lower prices, and improved rectification towers have been continued. However, basic efficiency improvement cannot be expected.

On the other hand, PSA is a method for producing 90 to 95% oxygen by a simple apparatus and a normal temperature operation.
It is used in small and medium-sized applications where the cryogenic method is not economically viable, such as electric furnaces, wastewater treatment, pulp bleaching, and ozonizer addition equipment. This PSA is a technology invented around 1957. From the beginning to the latest, efforts for energy saving improvement have been continued and many patents have been applied. In particular, adsorbent productivity [liter (oxygen) / kg]
-(Adsorbent) (H)] (which is an index of material saving in PSA) has been greatly improved. Recently, a new PSA with improved overall efficiency has been proposed by adopting LiX-type zeolite having better adsorption performance than the conventional adsorbent MS-5A zeolite and / or increasing the speed of the process (for example, see, for example). JP-A-2-68111, JP-A-7-185247, JP-A-3-526
No. 15, JP-A-6-55027).

[0005] In recent years, along with the rise of energy and environmental problems, various development projects are underway with the aim of industrializing a new power generation system and a new iron making method pursuing energy saving and material saving. Examples of these development projects include, for example, integrated coal gasification combined cycle, high temperature fuel cells, oxygen blast furnace method,
There is a smelting reduction iron making method and the like, and a large amount of oxygen and nitrogen are consumed in a practical system. Therefore, there is a great expectation for an oxygen / nitrogen producing apparatus and an oxygen / nitrogen producing method which have high overall efficiency by integrating energy saving and material saving (or a simple configuration, a low-priced apparatus, etc.).

[0006]

The evaluation scale of the adsorption separation system (apparatus) will be described. The smaller the following two index values, the better the adsorption / separation system. The same applies to other mixed gases, but description will be made taking oxygen production as an example. Oxygen consumption unit = KWH / m ³ (NTP) (oxygen) → energy saving scale Equipment price per oxygen production capacity Equipment price / m ³ (NTP) (oxygen) / H → material saving scale After all, the above oxygen Manufacturing cost [yen /
m ³ (oxygen)]. When both of the above are small, it is defined that the overall efficiency is high and is used below.

[0007] The cryogenic method representing the current "air separation method" mainly involves an ultra-low temperature process at around -200 ° C. For many years, energy saving has been pursued, and the improvement of equipment parts and machinery has almost reached the limit. It is difficult to expect a significant improvement in overall efficiency. On the other hand, PSA has improved yield in the early stage of development (energy saving), and recently "adsorbent productivity" [liter (90% oxygen) / kg (adsorbent) H] (material saving) [1 kg of adsorbent for 1 hour The larger the number of liters that can be produced, the more compact the equipment (material saving). PSA
Is used exclusively as a resource-saving measure for ] Was pursued, and energy saving and material saving were advanced. PSA has been almost completed with nearly 40 years of development, but there are still some issues to consider. The purity of oxygen is 99.5% or more in the cryogenic method, while the PSA of the cryogenic method is as low as 90 to 95%, but the oxygen intensity is substantially the same [0.35 to 0.5 KWH / m]. ³ (N
TP) oxygen, there is room for improvement, and this value is 0.069 of the semipermeable membrane work (theoretical value) for complete separation of air.
(KWH / m ³ oxygen), which is a considerably large value. The initial adsorbent productivity of PSA is about 10 to 15 [liter (90% oxygen) / kg- (adsorbent) (H)], and the latest adsorbent productivity of PSA is 40 to 60 [liter]. (90% oxygen) / kg- (adsorbent) (H)], and further increase the adsorbent productivity value. Oxygen-nitrogen can be co-produced. Current PSAs are single-use machines that produce only oxygen or only nitrogen. Current PSA
Although co-production of oxygen and nitrogen is possible, the system becomes complicated and the advantages of PSA are lost.

It is an object of the present invention to reduce energy demand, reduce oxygen intensity, improve adsorbent productivity, and significantly improve overall efficiency with a simple structure, for example, from raw air. It is an object of the present invention to provide a method for bulk separation of gas which can produce both oxygen and nitrogen at low cost.

[0009]

SUMMARY OF THE INVENTION The present inventor has developed a small oxygen-P
As a result of pursuing the limit of downsizing of the SA and conducting many experiments and evaluations, a “pulse flow control type PSA” (abbreviated as PF-PSA) was found, and 16 patent applications were filed earlier. That is, in order to increase the oxygen production amount with a fixed amount of adsorbent, it is necessary to increase the air load on the adsorbent by changing to a larger pump. As a result, the fluctuations of the gas flow entering and leaving the adsorption tower become severe. Therefore, the PF-PSA converts a gas flow into a pressure wave by opening and closing a high-speed on-off valve intermittently based on a fixed sequence, and realizes rapid and precise control of the gas flow entering and exiting the adsorption tower. It succeeded and achieved the adsorbent productivity of 400 [liter (90% oxygen) / kg- (adsorbent) (H)] (the world's highest value) with the simplest system having two columns.

Although the PF-PSA control method was applied to a large PSA to achieve high adsorbent productivity even in a large-sized machine, further experiments and evaluations were conducted with the aim of further improving the yield compared to a conventional PSA. Here, different from the conventional PSA, the present inventors have achieved "a new adsorption separation method in the entire co-current flow region" of the present invention in which all individual operations constituting the PSA are performed in co-current.

[0011] "A new adsorption separation method in the whole parallel flow area" of the present invention
Is similar to gas chromatography in that it is a co-current adsorption separation operation, except that non-adsorptive gas (such as He) is not used as a carrier gas, and gas chromatography is usually performed under all conditions. On the other hand, since the use conditions (pressure, temperature, composition, flow rate, etc.) of the carrier gas all vary from moment to moment (parametric and parameter variations), the present invention differs from ordinary gas chromatography in the following point. (Abbreviated as PGC).

According to the first aspect of the present invention, a raw material mixed gas containing a hardly adsorbable component (A) and an easily adsorbable component (B) is used in a smaller amount than the components (A) and (B) contained therein. After removing water, carbon dioxide, and other easily condensable gases that are extremely strongly adsorbent in a pretreatment device in advance, the column is filled with an adsorbent capable of selectively adsorbing the component (B), or adsorbed. A gas bulk separation method for obtaining the component (A) and / or the component (B) from one end (inlet end) to the other end (outlet end) of the adsorption column of the adsorption separation system including at least two columns. Then, each adsorption tower is subjected to the sequence operation of the following steps (1) to (2) from the other end (outlet end) at low power consumption and high overall efficiency at regular time intervals, alternately as a product (A). And / or obtaining component (B) A bulk separation process of gases by La metric gas chromatography. The raw material mixed gas is passed to the inlet end of the adsorption tower, the pressure in the column is increased from intermediate pressure to the maximum operating pressure, and the component (B) in the raw material mixed gas is selectively adsorbed. Component (A) and / or a gas rich in component (A) are taken out from the end (outlet end). While the raw material supply is continued, the component (A) and / or the gas rich in the component (A) are taken out from the outlet end near the maximum operating pressure. Stop supplying the raw material, depressurize this adsorption tower in the co-current direction,
The depressurized gas passes through the inlet end of another adsorption tower that is close to the pressure during the same circulation operation and that is increasing in pressure. The depressurization is continued, and the gas released and / or sucked from the adsorption tower is released to the atmosphere, recovered to another adsorption tower, or the component (B) product And take it out of the system. A gas rich in component (A) and / or component (A) is introduced as a purge gas in a co-current direction from another adsorption tower in the same circulation operation to the adsorption tower under the minimum operating pressure, and the components ( B) is replaced by component (A), and components (B) and / or
Alternatively, a gas rich in the component (B) is taken out from the outlet end of the adsorption tower. After the above operation, the gas from another adsorption tower whose pressure is approximated and whose pressure is decreasing during the same circulation operation is passed to the inlet end, and the pressure is increased to the intermediate pressure of the operation.

According to a second aspect of the present invention, in the method of the first aspect, the process is performed while the supply of the raw material mixed gas is continued.

According to a third aspect of the present invention, in the method of the first aspect, the step, the step of reducing the pressure, and the step of increasing the pressure are performed stepwise.

According to a fourth aspect of the present invention, in the method according to the first aspect, the raw material mixed gas is air, and the product gas is 90% or more oxygen and / or 90% or more nitrogen. And

According to a fifth aspect of the present invention, in the method according to the first aspect, the adsorbent is a zeolite-based molecular sieve material having a selective adsorption of nitrogen.

According to a sixth aspect of the present invention, in the method according to the first aspect, the adsorption / separation system comprises two adsorption columns.

According to a seventh aspect of the present invention, in the method according to the first aspect, the adsorption separation system comprises three or more adsorption columns.

According to an eighth aspect of the present invention, in the method according to the first aspect, the effluent gas of the process is supplied to another adsorption tower as a purge gas of the process, and the component (A) of the process is converted into a product. Features.

According to a ninth aspect of the present invention, in the method according to the first aspect, the effluent gas of the process is supplied to another adsorption tower as a purge gas of the process, and the component (A) of the process is converted into a product. Features.

According to a tenth aspect of the present invention, in the method according to the first aspect, the component (B) sucked by the co-current depressurized gas and / or the pump in the step is a product.

[0022] According to the eleventh aspect of the present invention, there is provided the method according to the first aspect, wherein silica gel is contained in the adsorption separation system.
A pretreatment tower filled with a pretreatment adsorbent selected from activated carbon, alumina gel, activated alumina, and zeolite is provided, and a part of the reduced pressure and / or purge discharge gas in the step and the step is used as a purge gas for regeneration of the pretreatment tower. It is characterized by providing.

According to a twelfth aspect of the present invention, there is provided the method according to the first aspect, wherein in step (1), the active ingredient in the gas discharged from the adsorption tower (the component (A) when the target product is the component (A), When the target product is the component (B), the component (B)] is recycled to another adsorption tower in the same system via a pump.

According to a thirteenth aspect of the present invention, in the method according to the seventh aspect, in the adsorption / separation system comprising three or more columns, the individual operation of connecting the two adsorption columns is performed by two adsorptions having an operating pressure approximation. Using a pressure difference from one adsorption tower to another adsorption tower, the gas flows in the co-current direction, and the pressure drop of one adsorption tower and the pressure rise of the other adsorption tower are performed, and the minimum operating pressure is reduced. A purging operation is performed on the adsorption tower.

According to a fourteenth aspect of the present invention, in the method according to the first aspect, when two adsorption towers are connected in an adsorption separation system comprising two or more towers, the pressure in the adsorption tower is in a rising process. The gas phase concentration distribution in the column is made such that the component (A) becomes rich toward the outlet end, and the gas phase concentration distribution in the adsorption tower in which the pressure in the adsorption tower is decreasing is such that the component (B) becomes rich toward the outlet end. In this case, the gas transfer rate is controlled so that there is no step between the outlet concentration of one adsorption tower and the inlet concentration of another adsorption tower.

The invention of claim 15 of the present invention is the invention of claim 10
In the method described above, the component (B) of the step is once collected in the intermediate tank, and prior to the step, the component (B) in the intermediate tank is recirculated to the inlet end of the adsorption tower via a pump and the inside of the tower is recovered. To the component (B), and thereafter, the gas in the adsorption tower and the component (B) in the adsorbent are sucked by a pump, and the component (B) is recovered as a high-purity product.

According to a sixteenth aspect of the present invention, in the method according to the sixth aspect, in an adsorption separation system having a two-column structure, two adsorption columns are connected in a parallel flow direction to equalize or partially equalize the pressure. And

According to a seventeenth aspect of the present invention, in the method according to the first aspect, the pressure reduction in the step is performed through a pressure energy recovery means such as an expansion engine, and the pressure energy is recovered as electric and / or mechanical energy. It is characterized by doing.

[0029] The invention according to claim 18 of the present invention relates to a simulator test for transferring gas by connecting two adsorption towers having a pressure difference through an automatic on-off valve in the method according to claim 1. In this, the time (t) change of the differential pressure (ΔP) between the inlet end and the outlet end of the downstream adsorption tower is measured using the opening time (Δti) of the automatic on-off valve as a parameter, Graphic (vertical axis: △ P, horizontal axis: t),
Δt when this figure is sine wave or sine wave approximation wave type
i is the pulse time, and the value obtained by subtracting △ ti from the half wavelength width is △ Z
i, the amount of gas passing through the automatic on-off valve (V
When i) is determined by the following equation (1), Δt ₁ (open) −ΔZ
₁ (closed) - △ t ₂ (Open) - △ Z ₂ (closed) ···· - △ t
According to a valve opening / closing sequence (valve opening time-time relationship) of i (open)-開放 Zi (closed), the gas movement amount (ΣVi) and gas movement speed [ΣVi / ( Σti + ΣZi)].

[0030]

(Equation 2)

[0031]

BEST MODE FOR CARRYING OUT THE INVENTION The method of the present invention uses a conventional gas chromatograph at the point where, for example, oxygen and nitrogen alternately flow from the end of the adsorbent column to the other end of the adsorbent column at regular intervals from the outlet end. It is similar to the graphy operation, but differs in the following points. No third gas [a gas other than the components (A) and (B)] was used as the carrier gas. When oxygen-nitrogen separation is performed by gas chromatography, non-adsorbing H
e gas is used. In the method of the present invention, the gas corresponding to the carrier gas is the component (A), the component (B), or a mixed gas thereof. It is not supplied at a constant flow rate. The composition, pressure, temperature, flow rate and the like of the carrier gas in the above-described method of the present invention periodically fluctuate in a fixed pattern and vary in parameters. In addition, the method of the present invention is a circulation operation utilizing the adsorption / desorption effect due to pressure fluctuation, and is similar to ordinary PSA (pressure fluctuation adsorption method), but the gas flows only in one direction (cocurrent) throughout the operation. Therefore, it is different from the conventional PSA in which the two operations of the co-current flow and the counter-current flow are combined.

The following briefly describes the progress from conventional PSA to parametric gas chromatography. An example will be described in which oxygen is produced from air. The basic process of a regular PSA consists of the following four individual operations. Focusing on one tower, pressurizing the raw material air → removing product oxygen → countercurrent depressurization →
Purge and return to There are about 2000 patents for commercial PSAs, most of which are variations on the above four-step process. Next, a typical process will be described. After the purging step of 1), a part of the product oxygen is caused to flow in the countercurrent direction (reflux), and the pressure in the column is returned to the intermediate pressure of the operation or more. 2) The decompression is performed, for example, in two or three stages of cocurrent and one stage of countercurrent. The cocurrent decompression gas is collected in another column, and the countercurrent decompression gas is released to the atmosphere. 3) A pressure equalizing operation is inserted between the step and the step to reduce or increase the pressure of the column. 4) The above countercurrent depressurization is promoted using a pump (referred to as a vacuum method). The minimum pressure of operation is vacuum.

The main cause of the inefficiency (yield reduction) in the conventional PSA is mainly due to the "countercurrent" operation described above,
The "countercurrent" decompression operation releases the active ingredient oxygen out of the system. To reduce this oxygen loss as much as possible, numerous improvements have been made over the years, and numerous PSA patents have been proposed to date.

The inventor of the present invention applied a part of the pulse flow control method to closely track the instantaneous changes in the amount and purity of gas in the countercurrent operation described above. The loss is much larger than the above-mentioned purge loss. When the countercurrent decompression is divided into three steps: initial, middle, and late, the initial loss is large, the purge effect is large, and the purge loss is small. It was found that should be used actively.

In order to recover a decompression loss, it is known in the prior art to divide the decompression into several separate operations of co-current and counter-current to "multi-stage" and to recover a decompressed gas rich in active ingredients into the system. However, in this case, three to four towers are required, and the configuration becomes complicated. Therefore, in the present invention, the depressurization is performed in the co-current direction, all the effective components are recovered in principle, the “purge” is actively used for regeneration of the adsorption tower, and the inside of the tower is prevented in order to prevent purge loss. Concentration gradients should be kept constant throughout the individual operation to minimize entropy loss due to mixing, and to recover as much pressure energy as possible, especially in large capacity machines, and that the constituent materials are iron and stone (zeolite), By eliminating the use of high-grade materials (copper, aluminum) such as the cryogenic method, energy savings, material savings, and the ability to co-produce oxygen and nitrogen are obtained, which are features that are not found in conventional PSAs. The overall efficiency, including all disposal costs, is significantly improved as compared to conventional air separation methods (cryogenic method, ordinary PSA).

The method of the present invention will be specifically described by taking air separation as an example. FIG. 1 shows a basic system for implementing the method of the invention. This basic system consists of three parts: a pump (1), a pretreatment device (3), a separation device (or system) (5), connecting pipes (2, 4, 6), and product takeoff valves (27, 28). . 1) Raw air is pressurized by a pump (1) and sent to a pretreatment device (3) via a pipe (2). 2) Pretreatment equipment (3) for moisture and carbon dioxide in raw material air
And sent out to the pipe (4) as dry air (DA). The pretreatment method may be any of an adsorption type, a refrigerant type, a membrane type, or a combination type thereof, but select a low-cost, energy-saving, and low product loss type so as not to lower the overall efficiency. Is preferred. 3) Dry air (DA) is a separation device (or system)
Sent to (5). DA is separated into oxygen and nitrogen by this device (5), and is alternately sent out to the line (6) at regular intervals. 4) By automatically opening and closing the automatic valves (27) and (28) connected to the pipeline (6) at regular intervals, the product oxygen (O
₂ ), collected as product nitrogen or waste nitrogen (N ₂ )
Product gas is stored in a product storage tank (not shown) connected downstream of each valve, from which it is sent to the consumer end. And as a separation mode, there are cases of the following 1-3. 1. Only oxygen is used as the product, and exhaust nitrogen is released to the atmosphere. 2. The product is only nitrogen, and the exhaust oxygen is released to the atmosphere. 3. Oxygen-nitrogen co-products. However, there are two cases when the nitrogen purity is 90% or more and when the nitrogen purity is 99% or more.

The gist of the method of the present invention lies in the following operation procedure in the separation apparatus or the adsorption separation system (5) shown in FIG. The adsorption / separation system (5) includes FIGS.
6 that does not include a pretreatment device in the adsorption / separation system (for large-scale machines), those that include a pretreatment device in the adsorption / separation system shown in FIGS. There are several basic aspects, such as different ones, but the basic operation (the method of the invention) is the same. FIG.
Is an example of a system using only oxygen as a product, the adsorption separation system shown in FIG. 8 is an example of a system using oxygen and low-purity nitrogen (90% or more) as products, and the adsorption separation system shown in FIG. Is oxygen and high purity nitrogen (99%
This is an example of a system using the above as a product.

FIG. 4 shows a method for bulk separation of gas according to the present invention.
An example in which oxygen and nitrogen are separated from air using an adsorption separation system (apparatus) having a two-column configuration shown in (A) will be described.
FIG. 4B shows an example of a system in which pressure energy in the step of reducing pressure is recovered by an expansion engine or a generator using pressure energy recovery means (EX), which will be described in detail later. FIG. 2A is a pressure sequence showing the relationship between [pressure in adsorption tower (A) and adsorption tower (B) to time], and FIG.
(B) is an explanatory view schematically showing the gas-phase oxygen concentration in the adsorption tower (A) and the adsorption tower (B) at the end of each step to. Symbols 1 to 4 in FIG. 2B indicate oxygen concentration, 1 is oxygen concentration 21% or less, 2 is oxygen concentration 21%,
3 indicates an oxygen concentration of 21 to 90%, and 4 indicates an oxygen concentration of 90% or more. Table 1 summarizes the relationship between these symbols 1-4 and the oxygen concentration.
Shown in

[0039]

[Table 1]

In the present invention, in the adsorption tower (A) and the adsorption tower (B), the individual operations of the following steps are repeated sequentially, so that oxygen and nitrogen alternate from the end of the adsorption tower at a fixed time interval. Is taken out. The air supplied to the adsorption separation system is "dry" air from which moisture, carbon dioxide, and the like have been removed by a pretreatment device in advance.

Next, the steps to order will be described. Raw material pressurization Raw material air is pressurized by a pump and sent to the adsorption tower (A) from the inlet end. And it refers increase the pressure of the adsorption tower (A) from the intermediate pressure (P _M). An oxygen-rich gas is taken out from the outlet end, and the adsorption tower (B) under the minimum operating pressure (P _L )
Are supplied in parallel as purge gas. Product delivery When the pressure in the adsorption tower (A) reaches the maximum operating pressure (P _H ), the feed of the raw material air is stopped. The product discharge valve is opened near the maximum operating pressure (P _H ), and product oxygen is discharged and sent to a product storage tank (not shown). A part of the product oxygen is supplied in parallel as a purge gas for the adsorption tower (B) or a gas for re-pressurization. Cocurrent decompression (1) The equalizing valve of the adsorption tower (A) is opened, and the adsorption tower (A) and the adsorption tower (B) are connected in parallel. By this operation, the adsorption tower (A)
The internal pressure decreases, and the internal pressure of the adsorption tower (B) increases. This is usually done until the pressures in the two columns have equilibrated,
(Equalization), and sometimes stops during equilibration (partial equalization). Co-current depressurization (2) After completion of the above process, the outlet end of the adsorption tower (A) is opened to the atmosphere, the residual gas in the tower is discharged in a co-current manner to the atmosphere, and further suctioned by a vacuum pump to make the pressure lower than the atmospheric pressure. Pressure (P
_L ). Purging An oxygen-rich gas is fed into the adsorption tower (A) under the minimum operating pressure from the outlet end of the adsorption tower (B) in parallel, and the residual nitrogen in the adsorption tower (A) is purged in parallel. Repressurization

After completion of the above steps 1 to 4,
Adsorption tower (A) and the adsorption column (B) was co-current connection, the adsorption tower (A) is the adsorption tower together with the pressure recovery until the intermediate pressure (P _M) (B) is a step-down. The operation of the above-mentioned step-is referred to as one cycle operation (one cycle time, T seconds). In the case of a two-column configuration, the adsorption tower (A) and the adsorption tower (B) repeat the same operation with a delay of T / 2 hours. In the case of a three-column configuration, the adsorption tower (A), the adsorption tower (B), and the adsorption tower (C) repeat the same operation with a delay of T / 3 hours.

The change in the oxygen concentration in the adsorption tower (A) and the adsorption tower (B) will be described with reference to FIG. In the steps, the raw material air is fed into the adsorption tower (A) (indicated by an arrow), whereby the gas concentration distribution in the adsorption tower (A) is shown in FIG. 2B toward the inlet-outlet side. 2-3
-4. Hereinafter, the same description method will be used. Product oxygen at the outlet end is collected as product. A part is supplied to the adsorption tower (B) as a purge gas (indicated by an arrow).

The desorption of nitrogen is started by the co-current depressurization step, and the concentration distribution of the gas in the adsorption tower (A) is shown in FIG.
As shown in (B), it changes from 1-2-3 to 1-1-2. Gases having an air concentration (O ₂ = 21%) or less are released into the atmosphere as exhaust nitrogen (may be recovered as crude nitrogen).

In the step (purge), the adsorption tower (A)
Oxygen is introduced in parallel from the inlet end,
Desorption starts sequentially from the nitrogen adsorbed at the inlet end,
It is pushed toward the exit end. The gas phase concentration in the adsorption tower (A) was from 1-1-2 to 4-1-1 as shown in FIG.
It changes like In a two-column system, since a concentration step occurs in this step, dry air (DA) starts from the inlet end.
Is leaked, and 1-1-2 → 2-1-1 → 4-2-1
It may be.

Step (re-pressurization or re-pressurization) While the pressure in the adsorption tower (B) is reduced, the oxygen concentration in the adsorption tower (A) is changed to the level shown in FIG. As shown, it changes from 4-1-1 to 3-4-1. The oxygen-rich gas gradually moves to the outlet end. The process (feed of raw material air) starts after the process, and as shown in FIG. 2B, the outlet end becomes oxygen-rich as the pressure increases from 3-4-1 to 2-3-4. In the step of increasing the pressure of the adsorption tower (A), the oxygen concentration of the adsorption tower (A) is gradually increased toward the outlet end. ), Controlling the amount of gas transfer between the adsorption towers (B). Adsorption tower (A), adsorption tower (B), adsorption tower (B)
When the flow and the adsorption tower (A) are connected in parallel, an operation is performed so that a concentration step does not occur at the connection portion (so that mixing due to the concentration difference does not occur).

The gas bulk separation method of the present invention will be described by way of an example in which oxygen and nitrogen are separated from air using an adsorption separation system (apparatus) having a three-column configuration shown in FIG. FIG.
FIG. 3A is a pressure sequence showing the relationship between [pressure in adsorption tower (A), adsorption tower (B) and adsorption tower (C) to time], and FIG. It is explanatory drawing which shows the gaseous phase oxygen concentration in a tower (A), an adsorption tower (B), and an adsorption tower (C) model. Symbols 1 to 4 in FIG. 3B indicate oxygen concentration, 1 is oxygen concentration 21% or less, 2 is oxygen concentration 21%, 3 is oxygen concentration 21 to 90%,
4 shows an oxygen concentration of 90% or more. Table 1 summarizes the relationship between the symbols 1 to 4 and the oxygen concentration.

Also in this case, the source gas is dry air from the pretreatment. As in the above two-column system, each of the adsorption tower (A), the adsorption tower (B), and the adsorption tower (C) is repeated T / 3 hours later to sequentially perform the following six steps. Source gas pressurization → product oxygen delivery Cocurrent decompression (1) Cocurrent decompression (2) Purge Repressurization (1) Repressurization (2)

Table 2 shows a comparison between the operation in the three-tower configuration system and the operation in the two-tower configuration system.

[0050]

[Table 2]

That is, the operation in the two-tower configuration system is one individual operation in the three-tower configuration system, and the operation in the two-tower configuration system is two individual operations in the three-tower configuration system.

Next, the individual operation of the three-tower configuration system will be described so as not to overlap with the description of the two-tower configuration system. Focusing on the adsorption tower (A), in the process, the raw material air is sent under pressure to the adsorption tower (A), and the product oxygen is extracted while increasing the pressure inside the adsorption tower (A). The remaining pressure is set to P in the adsorption tower (B).
_{Press L to} P _M1 (intermediate pressure (1)). In the process, the oxygen-rich gas is fed from the outlet end to the inlet end of the adsorption tower (B) in the co-current direction while the feed of the raw material air is continued.
, While increasing the pressure in the adsorption tower (B) from the intermediate pressure _{PM1 to the} intermediate pressure _PM2 (intermediate pressure (2)). Further, by connecting the adsorption tower (B) and the adsorption tower (C) in parallel, gas flows through the adsorption tower (A) → the adsorption tower (B) → the adsorption tower (C),
Purge the adsorption tower (C). At this time, as shown in the step of FIG. 3 (B), the column gas phase concentration becomes as follows, and the adsorption tower (A) [2-2-3] → the adsorption tower (B) [3-4-3] →
Adsorption tower (C) [3-2-1] The flow between the towers is controlled so that there is no step in the oxygen concentration at each column connection.

In the process, the minimum pressure P of the operation is _calculated from the intermediate pressure _PM2.
Reduce the pressure to _L. The decompressed gas is released to the atmosphere or recovered as crude nitrogen. Alternatively, the active ingredient in the reduced pressure effluent gas may be recycled and recovered to another tower in the same system through the path shown by the dotted line in FIG. 5 via the pump (10). At this time, when the product is intended for oxygen, the effluent at the initial and late stages of the decompression is mainly collected, and when the product is intended for nitrogen, the effluent at the intermediate stage of the decompression is recycled and collected. In the process, the oxygen-rich gas at the outlet end of the adsorption tower (B) flows in a parallel flow direction with the adsorption tower (B) → the adsorption tower (C) → the adsorption tower (A) to purge residual nitrogen in the adsorption tower (A). At this time, as shown in the step of FIG. 3B, the gaseous phase concentration of each column becomes as follows, and the adsorption tower (B) [2-2-3] → the adsorption tower (C) [3-4-3] → Adsorption tower (A) [3-2-1] The gas flow between the towers is controlled so that a step in the oxygen concentration does not occur at each column connection.

In the process, part of the product oxygen from the adsorption tower (C) leaks to the adsorption tower (A) under the minimum operating pressure (P _L ), and the pressure inside the adsorption tower (A) is increased from P _L → P _M1 Again.
In the process, by connecting the adsorption tower (C) → the adsorption tower (A) → the adsorption tower (B), the adsorption tower (A) is operated at the intermediate pressure P _M1 → P _M2.
Boost up to. At the same time, the adsorption tower (B) is purged by the oxygen-rich gas from the adsorption tower (A). At this time, the gaseous phase concentration of each column becomes as follows as shown in the step of FIG. 3B, and the adsorption column (C) [2-2-3]
→ Adsorption tower (A) [3-4-3] → Adsorption tower (B) [3-2]
-1] Control the flow between the columns so that a step in the oxygen concentration does not occur at each column connection. The separation operation in the three-column system has been described above.

The separation operation in the three-column system is advantageous over the separation operation in the two-column system in that there is no significant difference in oxygen concentration between the adsorption towers and there is no idle period of the pump. When the number of columns is four or more, a difference in oxygen concentration is less likely to occur than in a three-column system, but when the number of columns increases, the system becomes complicated and the price of the apparatus increases. Therefore, a two- to four-column system is appropriate.

The gas bulk separation method of the present invention is generally described for the two-column system and the three-column system described above. (1) All operations between the two columns are co-current flow operations. (2) The connection between two towers is pressure approximation, and the pressure rise process of one column and the pressure drop process of the other column are performed in combination. (3) When connecting the two columns, make sure that there is no step in the gas concentration. And controlling the flow between the towers.

In the present invention, the enthalpy loss can be minimized because the operation is performed at room temperature. However, to smooth the fluctuation of oxygen production between seasons,
The temperature of the raw material air may be maintained at a constant temperature of, for example, 15 to 25 ° C. Further, the operation may be performed at a temperature 10 to 15 ° C. higher than the normal temperature. A slightly higher operating temperature increases the rate of mass transfer and often has a positive effect on operation. The operating pressure range in the present invention is generally near the atmospheric pressure at which no excessive load is applied to the pump, but is classified into the following two types. (1) If the minimum pressure P _L is more or atmospheric pressure "pressure method"
Called. In this case, only the pressurizing pump may be used. (2) When the minimum pressure P _L is a vacuum pressure, it is called “vacuum method”. In this case, two types of pumps, one for pressurization and one for vacuum, are required.

Examples of the working pressure range (for small and medium-sized machines) in the present invention are as follows. (1) 0 to 7 kg / cm ² G (gauge pressure), typically 0 to 4.5 kg / cm ² G (gauge pressure) (2) 0.1 to 4 kg / cm ² abs (absolute pressure), standard More specifically, 0.2 to 3.5 kg / cm ² abs (absolute pressure).

An example of an adsorption separation system (hardware) suitable for carrying out the gas bulk separation method of the present invention will be described in more detail with reference to FIGS. The gas separation operation by the two-tower configuration system shown in FIG. 4A and the three-tower configuration system shown in FIG. 5 is as described above. In the method of the present invention, oxygen-rich gas and nitrogen-rich gas come alternately from each column. At this time, there are the following three cases (1) to (3). (1) FIG. 7 shows an example of an adsorption / separation system when only oxygen is used as a product and nitrogen is released to the atmosphere. (2) FIG. 8 shows an example of an adsorption separation system when oxygen and low-purity nitrogen are used as products. (3) FIG. 9 shows an example of an adsorption separation system when oxygen and high-purity nitrogen are used as products. In the above cases (2) and (3) where nitrogen is used as a product, a vacuum method is generally preferred. For medium- and small-scale production systems, generally, the pretreatment device and the separation device are not separately provided, and the pretreatment device (drying tower) is included in the latter separation device (adsorption separation system) to form a single system. Is preferred.

FIGS. 6 and 7 show such examples. In this case, the drying tower is generally regenerated for each circulation operation. In many cases, since only oxygen is used as a product, the remaining exhausted nitrogen is flowed in a countercurrent direction to the drying tower to purge and regenerate the desiccant. large·
To increase the maximum operating pressure in very large system (and a higher P _H device is a merit of compactification), it is desirable to recover the pressure energy of the step-down process in the expansion engine or generator. Actually, as shown in FIG. 4 (B), when transferring the gas from one adsorption tower to another adsorption tower while reducing the pressure, the pressure is lowered from the high pressure via the Ex (pressure energy recovery means) provided between the two towers. Expands to pressure. When recovering the pressure energy of the gas at the last stage of the pressure reduction, the valve 14a
It flows like (14b) -Ex-14c. Ex is an expansion engine or generator, pressure energy is recovered by Ex as mechanical energy or electrical energy,
It is stored in the system and is used for energy saving of the system. V in FIG. 4B indicates a bypass valve.

Two cases will be described for an example in which the pretreatment device is included in the adsorption separation system (air separation example). 1) FIG. 7 shows an example of a two-column system for the purpose of producing oxygen only. A "valve sequence" for operation of the adsorption separation system shown in FIG. 7 is shown in FIG. 7 are the same as those shown in FIG. 4 (A). In FIG. 7, D _A and D _B are drying towers (filled with a desiccant such as silica gel, alumina gel, activated alumina), AR is raw material air, O ₂ : product oxygen, W
N indicates waste nitrogen and WA indicates waste air. FIG. 7 shows valves 15a, 15b, 16a, 16b, and 17 for operation of the drying tower.
a and 17b are added. The operation of the valve 18 is the same as that of the valve 15 in FIG. 4A (opening of the abnormal pressure rise in the pipeline (4)).
Is a valve that performs The separation operation according to FIG.
(A) is the same as the separation operation shown in FIG. FIG. 13 shows an opening / closing operation (valve sequence) of each valve in one cycle in the adsorption separation system of FIG. Waste gas in cocurrent depressurization two stages and the purge step, valve 15a → D _A
→ flows through the valve 16a and the D _A in the countercurrent direction, the moisture adsorbed by the desiccant in the D _A, to promote desorption of such carbon dioxide is released as a purge gas (WN) to the atmosphere. The amount of gas required for purge is related like the operating pressure P _H and P _L is 5-30% of the dry air supplied to the adsorption column (A).

2) FIG. 8 shows an example of a two-column system for the purpose of oxygen and crude (low-purity) nitrogen. An example of a "valve sequence" for operation of the adsorption separation system of FIG. 8 is shown in FIG. The difference between the adsorption / separation system shown in FIG. 8 and the adsorption / separation system shown in FIG. 7 is that a vacuum pump (10) is provided, and valves 19 and 20 are provided around the vacuum pump (10) for smooth operation of the vacuum pump (10). , 21 and the valves 14a, 1
4b. The separation operation according to FIG.
(A), FIG. 10 (A), FIG. 7, and FIG. 13 are basically the same. For adsorption column (A), cocurrent depressurization valves 15a-D _A - valve 16a → the vacuum pump (1
0) → Valve 21 → Regeneration operation communicating with the atmosphere, and thereafter, operation of pulling down to vacuum pressure are performed separately. Since the latter gas is rich in nitrogen components, it is recovered into a nitrogen storage tank (not shown) via the valve 14a-the vacuum pump (10) -the valve 20.

Preferred embodiments for carrying out the gas bulk separation method of the present invention include the following embodiments. 1. Oxygen (oxygen concentration 90% or more) is used as a product using air as a raw material. 2. Oxygen (oxygen concentration 90% or more) and / or nitrogen (nitrogen concentration 99% or more) are used as products using air as a raw material. 3. The system for the separation is composed of 2 to 4 columns. 4. The automatic valve that operates the adsorption separation system is an on-off valve that is operated by electric power and / or pneumatic pressure. 5. The small-capacity machine is configured as an integrated system of a pretreatment device for raw material mixed gas and a separation device, and performs integration and circulation operations. 6. The gas separation operation temperature should be near normal temperature (25 ± 10 ° C). 7. The gas separation operation pressure is 0 to 4.5 in the pressurization method.
kg / cm ² G, -0.8 to +3.5 in vacuum method
kg / cm ² (however, for medium and small capacity machines). 8. When the component (A) is used as the target product, it is necessary to stop the feed of the source gas immediately before the leading edge of the adsorption zone of the component (B) reaches the end of the column when feeding the source gas into the column. preferable. When component (B) is used as the target product, the concentration of component (A) in the effluent gas from the end of the column gradually decreases, and the feed gas feed is stopped immediately before the inlet concentration and the outlet concentration become equal. Is preferred.

[0064]

[Action] In the present invention, the countercurrent depressurization operation that causes PSA loss is performed in parallel, and all useful components are recovered in the system in principle. The concentration gradient formed in the system is maintained through each individual operation. The entropy loss was minimized, and the heat and cold energy generated in the system was effectively utilized in the system to minimize the enthalpy loss, and the pressure energy was reduced to the pressure of other adsorption towers or expansion engines. Energy recovery has been remarkably improved due to the energy recovery means. 2. In the present invention, using a simple configuration, using cheap components (mainly iron and adsorbent), and using a high load operation by adopting an on-off valve and a pulse flow control method (PF),
The adsorbent productivity was improved and the compactness was achieved, which significantly improved material savings. 3. The overall efficiency, which leads to energy savings and material savings, is significantly improved compared to the conventional cryogenic method and conventional PSA. For example, a large amount of inexpensive oxygen and nitrogen can be supplied from raw material air. . 4. The method of the present invention has also enabled ultra-compact units for small capacity machines that cannot be achieved by the cryogenic method. 5. The method of the present invention enables co-production of oxygen and nitrogen, which is extremely difficult with conventional PSAs.

[0065]

Next, the present invention will be described in more detail with reference to Examples, but it should not be construed that the invention is limited thereto without departing from the gist of the present invention. (Example 1) FIG.
FIG. 10A shows an adsorption / separation system (apparatus) having a two-column configuration, a pressure sequence showing the [pressure-time in the adsorption tower (A) and the adsorption tower (B)] in FIG.
An example will be described in which oxygen (useful gas) and nitrogen (unwanted gas) are separated from air using the valve sequence shown in (A) and (B). In the adsorption tower (A) and the adsorption tower (B),
Adsorbents a and b for selectively adsorbing unnecessary gas are stored. The adsorption tower (A) and the adsorption tower (B) are of the same specification.

A mixed gas (dry air) (DA) is fed in from the lower side in FIG. 4A, and an unnecessary gas (nitrogen) is adsorbed and sent out to the upper side. The pump (1) sucks and pressurizes the raw material air (AR) and sends it out to the pipeline (2), and the pretreatment device (3)
, Removes moisture, carbon dioxide, trace impurities, etc. from the air, and sends it out to the pipe (4) as pressurized dry air (DA).
The water is fed from the inlet end below the adsorption tower (A) and the adsorption tower (B) through the pipe (5a) and the pipe (5b). The useful gas (oxygen) obtained from the upper side (outlet end) of the adsorption tower (A) and the adsorption tower (B) passes through the pipe (6a) and the pipe (6b) via the pipe (7) to the product storage tank ( (Not described).
A useful gas (oxygen) and an unnecessary gas (nitrogen) are alternately delivered to the pipeline (6a) and the pipeline (6b) at predetermined time intervals. The pipe (8) is a path for discharging unnecessary gas. In addition, a vacuum pump (10) is provided in the pipeline (8),
Desorption of unnecessary gas may be promoted. Each on-off valve, 11a,
11b, 12a, 12b, 13a, 13b, 14a, 1
Reference numerals 4b denote valves for opening and closing the passage of gas through the pipes in which they are arranged. The valves 4b are opened and closed by a control unit (not shown) so as to perform required steps.

The opening / closing valves 11a and 11b contribute to the above-mentioned feeding operation. The opening / closing valves 12a and 12b contribute to the collecting operation of required gas (oxygen). The opening / closing valves 13a and 13b correspond to the adsorption tower (A). And a valve for the co-current connection operation of the adsorption tower (B) or the adsorption tower (B) and the adsorption tower (A), and contributes to the "equalizing operation" and the "purge operation". -The on-off valves 14a and 14b contribute to release of unnecessary gas (nitrogen) to the atmosphere. The on-off valve (15) contributes to alleviating or opening the excessive pressure rise in the pipe (4) at the time of each valve switching operation.・ The pressure gauges (P _A ) and (P _B ) are the adsorption tower (A),
The pressure inside the adsorption tower (B) is monitored.

In the first embodiment, each open / close valve is controlled as shown in FIGS. 10A and 10B in the valve sequence during the process of one cycle, and the pressure gauges (P _A ) and (P _The pressure change seen in _B ) is as shown in FIG. In FIGS. 10A and 10B, each on-off valve is open only during the hatched period, and is stopped during the other periods. FIG.
The pressure change in (A) is a model diagram, and is actually a deformation curve accompanied by a transient change in each pipe line and each adsorption tower due to the opening and closing of each on-off valve.

The order of each operation in one cycle process will be described. Basically, each pressure change in each of the adsorption towers (A) and (B) is measured for one cycle period (T seconds), for example, T = 60.
The driving operation is performed with a two-phase change curve caused by a phase difference of 1/2 of a second, that is, 30 seconds.
The pressure change in the adsorption tower (B) is the same as the pressure change in the adsorption tower (B) shown in FIG. 2 (A). The operation is performed so as to perform the second phase pressure change having the change indicated by the polygonal line below. Each pressure change is based on the maximum pressure P _H and the minimum pressure P _L
And three pressure points of an intermediate pressure P _M which is approximately equally divided between them.

First, when the operation is started, each pressure in each of the adsorption towers (A) and (B) follows various transitional courses for several cycles, and eventually, as shown in FIG. At the start point (T _s ) of one cycle, the pressure of the adsorption tower (A) becomes P _M during the rise, and the pressure of the adsorption tower (B) becomes P during the fall.
_M or near it. The operation from the starting point T _S will be described below in the order of steps, mainly on the operation on the adsorption tower (A), that is, the pressure change shown in the upper part of FIG.

Step Raw Material Pressing Operation 0 (= T _S ) to 2
5 seconds The on-off valve 11a is opened from the start point T _{S for} 25 seconds. Dry air clogging the feed gas do for pressurized pumping entering the adsorption column (A), the pressure of the adsorption tower (A) moves from the intermediate pressure P _M to the highest operating pressure P _H, adsorbent waste gas (nitrogen) It is adsorbed in (a) and the useful gas (oxygen) is sent out to the upper side (outlet end) of the adsorption tower (A). At the same time, the on-off valve 14b
By the possible states discharged conduit (8) the pressure of the opening 20 seconds to adsorption column (B), moves the pressure of the adsorption tower (B) from the intermediate pressure P _M in the minimum operation pressure P _L . At this time, by suction with a vacuum pump (10), it can be the minimum operation pressure P _L to below atmospheric pressure. Note also that in this operating period, from the start point (T _S), after 15 seconds, opening and closing valve (13a) opened for five seconds, there oxygen-rich gas of the adsorption tower (A) outlet end to the minimum operating pressure P _L A flow is made to flow from the inlet end of the adsorption tower (B) in a co-current direction to purge the interior of the adsorption tower (B). By this operation, desorption of the unnecessary gas (nitrogen) remaining in the adsorption tower (B) is promoted, and the valve (14b) and the pipe (8)
It is released to the atmosphere through. After the purge operation is completed, the on-off valve 13a is opened for a short time to maintain the pressure in the adsorption tower (B) higher than the atmospheric pressure [5 in FIGS. 10 (A) and 10 (B)].
a)].

Step Product removal operation (20 to 25 seconds) By the operation of the step, when the pressure of the adsorption tower (A) rises and reaches near the maximum operating pressure, the on-off valve (12a) is opened.
Collect useful components (oxygen). That is, the starting point (T
20 seconds after _S ), the on-off valve (12a) is opened for 5 seconds,
The useful component (oxygen) is extracted from the outlet end of the adsorption tower (A).

Step Co-current decompression (1) operation (25 to 30)
Second (T _M )) When 25 seconds have passed from the starting point T _S , the on-off valve 11a is closed, the valve 13a is opened, and the adsorption tower (A) and the adsorption tower (B) are connected in parallel. By this operation, the pressure of the adsorption tower (A) decreases from the highest operating pressure (P _H ) to the intermediate pressure (P _M ), and the pressure of the adsorption tower (B) decreases from the lowest operating pressure (P _L ) to the intermediate pressure (P _M). )
Rise up to That is, when the pressures of the adsorption tower (A) and the adsorption tower (B) are equilibrated, the transfer of the gas from the adsorption tower (A) to the adsorption tower (B) is stopped (referred to as pressure equalization). During the pressure equalizing operation period, the on-off valve (15) is opened for 5 seconds to avoid an abnormal increase in the pressure in the pipe (4).

Step Co-current decompression (2) operation (30 (T
_M) at -45 seconds) starting (T _S) 30 seconds, reaching the intermediate point (T _M).
The operation of the process is completed in T _{S to} T _M (30 seconds). After the operation of the process is completed, the valve (14a) is opened for 20 seconds.
The pressure of the adsorption tower (A) drops from the intermediate pressure (P _M) to the lowest operating pressure (P _L) after 15 seconds.

Step Purge Operation (45-50 Seconds) The operation of the step following the operation of the step is stopped in 15 seconds, but the valve (14a) is kept open. That is, the adsorption tower (A) is maintained at the minimum operating pressure (P _L ) for 20 seconds. After 15 seconds from the middle point (T _M ) of one cycle, the valve (1
3b) is opened for 5 seconds, and the oxygen-rich gas at the outlet end of the adsorption tower (B) is introduced in a co-current direction from the inlet end of the adsorption tower (A) to promote the desorption of the residual unnecessary components in the adsorption tower (A). The desorbed waste gas (exhaust nitrogen) is sent out to the pipe line (8) via the valve (14a) and released to the atmosphere.

Step Re-pressurizing operation [55-60 seconds (T
_E )] The valve 14a opened at T _M is closed after 20 seconds. The valve 13b is opened for a short time for 5 seconds before the re-pressurization operation is started, and the inside is maintained at a positive pressure (atmospheric pressure or higher) (indicated by 5a in FIG. 11B). 25 seconds after T _M , the valve 13b is opened for 5 seconds,
A re-pressurizing operation is performed. During this operation, the adsorption tower (A),
The valves at the inlet to outlet ends of the adsorption tower (B) are all closed except the valve 13b. The opening of the valve 13b, the adsorption tower (B) outlet - two towers are connected in parallel flow direction of the inlet adsorption column (A), the adsorption column (B) is a step-down to the P _H → P _M, the adsorption tower (A )
The pressure is restored from P _{L to} P _M , and preparations for feeding raw materials are completed. After the end of the process operation, the valve 11a is opened again, and the second
The cycle begins. Valve 15 for 55-60 seconds from starting point T _S
To avoid an abnormal pressure increase in the line (4).

Although the opening / closing operation of each valve in one cycle has been described focusing mainly on the adsorption tower (A), the same operation is also performed on the adsorption tower (B) with a delay of 30 seconds.
The related operation between the adsorption tower (A) and the adsorption tower (B) is shown in FIG.
(A) and (B). Co-current decompression (1)
There is another example in which the operation is stopped and the operation of the step is started while the pressures of the two columns connected in parallel by operation are balanced (partial pressure equalization method). Also, while continuing to pressurize the high pressure tower,
Or there is another example of connecting two columns while continuing to depressurize the lower pressure column.

In the operation of the method of the present invention, it is necessary to quickly and precisely control the amount of gas flowing into and out of the adsorption tower in order to improve the overall efficiency. Generally, a throttle mechanism such as an orifice, a diaphragm control valve, or the like is attached to a pipe near the above-mentioned automatic opening / closing valve, and the gas flow rate flowing through the pipe at the time of opening and closing the valve is adjusted before the continuous operation. The operation start operation becomes complicated, and the addition of the adjusting means in addition to the automatic opening / closing valve complicates the configuration of the device and increases the price of the device,
In the present invention, all the valves used are unified into on-off valves, and the optimal gas amount for the individual operations of the above six steps is turned on and off because there is a possibility that energy loss may be caused by flow path resistance. Preferably, the control is performed by intermittent opening and closing operations based on a precise sequence of valves.

In FIG. 10A, the purge supply valve 13
a or 13b is opened and closed intermittently as shown in FIG. In the first embodiment, the valve 13a is set to 15.0-1.
5.5,17.5-18.0,20.0-20.5 as the opening and closing operations, by feeding oxygen-rich gas as three continuous pressure wave in the adsorption column (B) in the minimum operation pressure P _L I have. Then, control is performed so that the total flow rate of the two waves of the first pulse and the second pulse becomes a gas amount necessary for the “purge operation”. The third pulse (indicated by 5a) is an operation for maintaining the pressure in the adsorption tower higher than the atmospheric pressure. The rapid and precise flow control method described above is called “Pulsed Flow Control”.
(PF).

The PF will be described in detail with reference to FIGS. FIG. 16 is a model diagram of a small simulator for individual operation of the present invention. In FIG. 16, A is an adsorption tower, V ₁ and V ₂ are on-off valves, a is an adsorbent, and P ₁ and P
₂ indicates a pressure sensor, R indicates a reservoir, and ΔP indicates a differential pressure. An experimental operation example is shown below. After activation, the adsorbent a is filled with nitrogen and placed under the atmospheric pressure or the vacuum pressure to adjust the initial conditions. The initial pressure P _2. Oxygen is charged into the reservoir (R) and kept at a constant pressure (P ₁ ) (P ₁ >
P _2). On - Off valve V ₁ opened 0.1 seconds, graphically recording the temporal variation of the differential pressure △ P of the adsorption tower (A). The results are shown in FIG. On - off valve V ₁ 0.2,0.3
The time change of ΔP of the adsorption tower (A) is recorded graphically in seconds, etc. FIG. 17B shows the result when 0.2 seconds have passed.
Shown in

The chevron and waveforms of A and B in FIG. 17 are compared.
As shown in FIG. 17A, when Δt = 0.1, the peak of the chevron becomes an acute angle with a collapse. As shown in FIG. 17B, when Δt = 0.2, the peak of the chevron is almost symmetrical and approximates a sine wave. The latter case indicates that a certain amount of gas mass smoothly propagates as a pressure wave in the column. The amount of gas mass or gas wave at this time indicates the minimum optimal gas amount. In the waveform diagram of FIG. 17B, H _B relates to the gas propagation velocity, and T _B indicates the waiting time (pause) of the first wave and the second wave. In the pulse flow control in the pulse operation in the process of the first embodiment, the operation of 0.5 pulse-2.0 pause (first pulse) is performed in the second, third, and third operations. At this time, the flow rate of one pulse is represented by the following equation (1) (empirical equation).

[0082]

(Equation 3)

(Example 2) The method for bulk separation of gas of the present invention was carried out by a three-column adsorption / separation system (apparatus) shown in FIG. 5 and an [adsorption tower (A), adsorption tower ( B)
And pressure within the adsorption tower (C) to time] and an example in which oxygen and crude nitrogen are separated and produced from air using the valve sequence shown in FIG.
The adsorption tower (A), the adsorption tower (B), and the adsorption tower (C) have the same specifications. The inside of the adsorption tower (A), the adsorption tower (B) and the adsorption tower (C) is packed in a column shape with an adsorbent (MS-5A) for selectively adsorbing nitrogen gas. Among the symbols in FIG. 5, the same symbols as those described in the first embodiment (FIG. 4A) indicate the same functions. DA indicates pressurized dry air. -The on-off valves 21a, 21b, 21c contribute to the operation of feeding the pressurized dry air;-The on-off valves 22a, 22b, 22c contribute to the product oxygen sampling operation;-The on-off valves 23a, 23b, 23c are two towers. The on-off valves 24a, 24b, 24c contribute to the operation of collecting crude nitrogen. -The on-off valves 26a, 26b, 26c contribute to the operation of collecting the active ingredient. -The pipes 9a, 9b, 9c are pipes for connecting two towers in parallel. P _A , P _B , and P _C are pressure gauges for monitoring the pressure inside the adsorption tower (A), the adsorption tower (B), and the adsorption tower (C), respectively.

[0084] During process of the valves is 1 cycle, when viewed in the valve sequence is controlled as shown in FIG. 11, and the pressure gauge P _A, P _B, the pressure change was P _C Demi in FIG 3 (A) As shown. In FIG. 11, each on-off valve is open only during the hatched period and is stopped during the other periods.
In FIG. 11, the number in the hatched part is the adsorption tower (A).
Are shown below. The pressure change in FIG. 3 (A) is a model diagram, and is actually a deformation curve accompanied by transient fluctuations in each pipe line and each adsorption tower due to opening and closing of each on-off valve. A description will be given in accordance with each operation sequence in one cycle process. The operation from the start point T _S will be described mainly on the operation on the adsorption tower (A), that is, the pressure change shown in the upper part of FIG.

Process Raw material pressurization 0 (= T _S ) to 20
Sec Dry air pressurized pumping input city adsorption column (A) of the adsorption tower (A) the maximum operating pressure pressure (indicated by P _A) from the intermediate pressure P _M2 in P
Raise to _H. Adsorb nitrogen in the air with the adsorbent column,
The oxygen is delivered to the outlet end of the adsorption tower (A). Also in this operation period, the pressure in the adsorption tower (A) sends out oxygen of a predetermined amount open 5 seconds oxygen delivery valve 22a reaches the vicinity of P _H to the line (7). A product oxygen storage tank (not shown) is connected to the pipeline (7), from which the product oxygen is sent to the consumption end. Further, the valve 23a is opened for 1.0 seconds to re-pressurizing (1) of the lowest operating pressure P _L adsorption tower under (B) (Figure 1
5a in 1).

Step Co-current depressurization (1) 10 to 20 seconds The valve 23a is opened for 10 seconds while the supply of the dry air to the adsorption tower (A) is continued, and the adsorption tower (A) and the adsorption tower (B) are opened. )
Are connected in parallel to collect the oxygen-rich gas at the outlet end of the adsorption tower (A) into the adsorption tower (B). The valve 23b is opened a little later, and the adsorption tower (B) is moved from the intermediate pressure _PM1 to _PM2. Until then, pressurize again. At the same time, the adsorption tower (A) is a step-down from the highest operating pressure P _H until P _M2.

Step Co-current depressurization (2) 20 to 30 seconds The valve 24a is opened for 10 seconds. The nitrogen-rich gas remaining in the adsorption tower (A) is sent to a pipe (8). From there, it is sent to a nitrogen storage tank (not shown). When oxygen production is intended, it is released to the atmosphere via line (8). The pressure in the adsorption tower (A) drops to the minimum operating pressure P _L. When recovering the oxygen content in the reduced pressure effluent gas, the valve 20b and the pump (1
0) -Adsorption tower (B) through valve 26b and the path shown by the dotted line
Recycle and recover.

[0088] During step purging 30-40 seconds this operation period, the adsorption tower (A) is under minimum operating pressure P _L. As shown in FIG. 3 (A), an oxygen-rich gas for purging flows in a parallel flow direction with the adsorption tower (B) → the adsorption tower (C) → the adsorption tower (A), and the nitrogen-rich gas remaining in the adsorption tower (A). Is pushed out to the adsorption tower (A) at the outlet end, and sent out to the pipe (8) via the valve 24a. The important thing about this operation is
In order to prevent a step of the concentration gradient from occurring at the connection between the two columns, the flow rate must be adjusted so that the pressure change in each column follows the pressure sequence diagram [FIG. 3 (A)].

Step Repressurization (1) 41 to 42.0 seconds The valve 23c is opened for 1.0 second to repressurize the adsorption tower (A) (1). This is shown by the steps in FIG. Adsorption tower (A)
The internal pressure rises to about 0.25 kg / cm ² G.

Step Repressurization (2) 50.0-60.
0 second The valve 23c is opened for 10 seconds, the adsorption tower (C) and the adsorption tower (A) are connected in parallel, and while the adsorption tower (C) is depressurized, the re-pressurization (2) of the adsorption tower (A) is performed. Do. After a short delay, the adsorption tower (A) and the adsorption tower (B) are connected in parallel, and a purge gas is supplied from the adsorption tower (A) to the adsorption tower (B). The pressure inside the adsorption tower (A) is increased from 0.25 kg / cm ^{2 to} 2.5 kg / cm ² .

As described above, mainly focusing on the adsorption tower (A),
The opening / closing operation of each valve at a cycle time of 60 seconds is shown, but the adsorption tower (B) and the adsorption tower (C) also have 60/60 cycles respectively.
A similar operation is performed with a delay of 3 = 20 seconds. The related operations and the like between the adsorption tower (A), the adsorption tower (B), and the adsorption tower (C) are as shown in FIG.

In the operation of a system having three or more towers, the flow is regulated because the three towers are connected in parallel and gas flows. The depressurization operation commonly used in a two-column system stops the operation when the two columns are connected in parallel and the pressure is equilibrated.
At this time, there is no need to consider the control of the gas transfer amount (total amount). However, it is necessary to adjust the flow rate so that the pressure drop (rise) is linear on the pressure sequence diagram and just ends in a predetermined time. In the case of a three-column system, care must be taken to ensure that both the amount of gas transferred (total) and the speed of movement (along the pressure sequence) are optimal.

The four-column system and the separation operation can be performed in the same manner as in the three-column system. Adsorption / separation system (apparatus) having four columns shown in FIG. 6 and FIG.
An example in which oxygen and crude nitrogen are separated and produced from air using the valve sequence shown in FIG. In the case of a four-column system, the same six steps as those in the three-column system are performed. 6 steps and 3 in the case of a 4-tower system
Table 3 shows the results obtained by comparing the six steps (1) to (6) in the case of the tower configuration system.

[0094]

[Table 3]

"Co-current decompression and re-pressurization are divided into three stages"
However, it is different from a system with three towers. However, the basic concept is the same.

(Example 3) An example of producing oxygen and high-purity nitrogen from air using an adsorption separation system (apparatus) having a two-column structure shown in Fig. 9 and a valve sequence shown in Fig. 15 will be described. Adsorption tower: inner diameter 53 m / m × length 230 m / m × 2 tower Adsorbent: MS-5A (filling amount into adsorption tower (A); 298)
g, the amount charged into the adsorption tower (B); 305 g) The adsorption separation system (apparatus) having a two-column structure shown in FIG. 9 and FIG.
The basic adsorption / separation system having a two-column configuration shown in Fig. 9 is the same as that shown in Fig. 9 except that a valve and a nitrogen reservoir (nitrogen storage tank) are provided for high-purity nitrogen production. Duplicate points are omitted. DA: pressurized dry air O ₂ : product oxygen (purity 93% or more) HN ₂ : high-purity nitrogen (purity 99.5% or more) WA: exhaust air R _O : product oxygen storage tank _RN : product nitrogen storage tank 10 : Vacuum pump All valves are on-off valves. In the third embodiment, each valve is controlled as shown in FIG. 15 in a valve sequence during one cycle process, and is opened only during a hatched period.
The number of the hatched portion indicates the order of the steps for the adsorption tower (A).

The one-cycle operation includes the following eight steps. The difference from the basic sequence of the two-column configuration shown in Example 1 is that the process of the basic sequence is co-currently depressurized (2).
Only the "nitrogen replacement operation" and the "nitrogen recovery operation" for high-purity nitrogen production are inserted between the process and the process purge operation. Hereinafter, the separation operation of the present example will be described by focusing attention on the adsorption tower (A). (Valve open time in one cycle) Process Pressurization of raw material 0 to 25 seconds Process Product oxygen extraction 15 to 20 seconds Process Co-current depressurization (1) 25 to 30 seconds Process Co-current depressurization (2) 30.0 to 32.5 seconds Step Nitrogen replacement 30.0-37.5 seconds Step Nitrogen recovery 37.5-50.0 seconds Step purge 50.0-50.5, 52.
5-53.0 seconds Process re-pressurization 55.0-60.0 seconds

The steps are the same as described in the first embodiment. The steps will be described. Step Nitrogen replacement 30.0-37.5 seconds 30.0 seconds after the start time T _{S of} one cycle, the valve 20
a, 20b, 17a, opening the four valves of the 18a, the high-purity nitrogen nitrogen storage tank R _N is fed to cocurrent direction from the adsorption tower (A) inlet end, the vapor phase part adsorption column (A) The remaining oxygen is pushed to the outlet end and released into the air via the valve 18a. This operation is stopped when the high-purity nitrogen reaches the outlet end of the adsorption tower (A).

Step Nitrogen recovery 37.5 to 50.0 seconds When the operation of the step is completed, the valves 14a and 20c are opened, and the adsorption tower (A) is evacuated by the vacuum pump (10). By this operation, the gas phase in the adsorption tower (A) and the nitrogen present in the adsorption layer are sucked and sent to the nitrogen storage tank ( _RN ).
From there, it is pressurized and sent to the consumer end as high purity nitrogen (HN ₂ ). Note that the nitrogen storage tank preferably has a flexible structure. Oxygen is purged and supplied to the adsorption tower (A) under vacuum after the operation of the step by the intermittent opening operation of the valve 13b (PF control method). In this example, 0.
Two 5-second pulses are operated. The flow of gas into and out of the adsorption tower (A) and the adsorption tower (B) and the operation state of the pump in the above one cycle operation are apparent from the valve sequence shown in FIG. Thus, every 30 seconds, 90% or more of oxygen and 9% are alternately discharged from the adsorption tower (A) and the adsorption tower (B).
More than 9.5% of nitrogen was produced.

The separation operation in Example 3 is not limited to a two-column system, but can be performed in a system having three or more columns. In a system with three or more towers, it is easy to eliminate the idle period of the pump (1) and the vacuum pump (10).

Examples 1 to 3 and FIGS. 10 to 1
The valve sequence shown in FIG. 5 is a representative example, and can be implemented in various other modified embodiments. However, the valve sequence is entirely within the scope of the present invention unless departing from the gist of the present invention.

[0102]

The gas separation method of the present invention uses an adsorption / separation system (equipment) having a simple structure, uses inexpensive materials, and has a compact adsorption / separation system (equipment). Compared with the cryogenic method, the equipment price is remarkably lower and the constituent materials are iron and stone (adsorbent) which are harmless to the environment. Therefore, it is much more economical in consideration of disposal costs.
In the gas bulk separation method of the present invention, the gas flows in a certain direction while the pressure fluctuates in a certain cycle, and through this flow process,
Maintaining a constant concentration gradient (isentropic process), making effective use of the heat of adsorption and desorption (cold heat) generated in the adsorption separation system (isoenthalpy process), and using pressure energy in other adsorption towers Or a thermodynamic energy saving process by recovering it as mechanical and / or electrical energy by an expansion engine or the like. As described above, the gas bulk separation method of the present invention is an energy-saving and material-saving process,
The overall efficiency has been remarkably improved, and it has become possible to separate and supply a large amount of inexpensive oxygen, nitrogen or hydrogen from the raw material mixed gas.

In recent years, with the rise of energy and environmental issues, large-scale development projects for new ironmaking methods such as the oxygen blast furnace method, the smelting reduction steelmaking method, integrated coal gasification combined cycle, and high-temperature fuel cells, and new power generation systems are in progress. However, these next-generation technologies consume large amounts of gases such as oxygen and nitrogen. The gas bulk separation method of the present invention greatly contributes to economical establishment as a large-scale and inexpensive gas supply means for the next-generation technology.

Further, the gas bulk separation method of the present invention comprises:
This enables a compact and compact gas separator that can be mounted on automobiles. That is, it is expected to be installed in a diesel vehicle and used as an oxygen flame for particulate burnout, or as an oxygen, nitrogen source, hydrogen separator, or the like for a fuel cell electric vehicle, which is useful for reducing the size and energy of the battery. .

The bulk gas separation method of the present invention not only separates oxygen and nitrogen from air but also separates other mixed gases (eg, H ₂ —CO ₂ , H ₂ —N ₂ , N ₂ —CO, etc.). Is also applicable. As described above, the gas bulk separation method of the present invention has great industrial value.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a basic system for implementing a method of the present invention.

FIG. 2A is a diagram illustrating a pressure sequence of each column of the two-column system according to the present invention, and FIG. 2B is an explanatory diagram illustrating a change in a gas phase concentration distribution in each adsorption column.

FIG. 3A is a diagram illustrating a pressure sequence of each column of the three-column system according to the present invention, and FIG. 3B is an explanatory diagram illustrating a change in a gas phase concentration distribution in each adsorption column.

FIG. 4 (A) is an explanatory diagram showing an example of a basic system (two-tower configuration) according to the present invention, and FIG. 4 (B) is a diagram for expanding pressure energy in a pressure-reducing process using a pressure energy recovery means (EX) It is explanatory drawing which shows the modification of the example of a basic system (two tower structure) shown in (A) at the time of collection | recovering by an engine or a generator.

FIG. 5 is an explanatory diagram showing an example of a basic system of a three-tower configuration according to the present invention.

FIG. 6 is an explanatory diagram showing an example of a basic system having a four-tower configuration according to the present invention.

FIG. 7 is an explanatory diagram showing an example of a basic system including a drying tower in a two-tower configuration according to the present invention.

FIG. 8 is an explanatory diagram showing an example of a basic system including a drying tower and a vacuum pump in a two-tower configuration according to the present invention.

FIG. 9 is an explanatory diagram showing an example of a basic system including a vacuum pump, a product oxygen storage tank, and a product nitrogen storage tank in a two-tower configuration according to the present invention.

FIG. 10 is an explanatory diagram showing an example of a valve sequence for operating the basic system shown in FIG. 4;

FIG. 11 is an explanatory diagram showing an example of a valve sequence for operating the basic system shown in FIG. 5;

FIG. 12 is an explanatory diagram showing an example of a valve sequence for operating the basic system shown in FIG. 6;

FIG. 13 is an explanatory diagram showing an example of a valve sequence for operating the basic system shown in FIG. 7;

FIG. 14 is an explanatory diagram showing an example of a valve sequence for operating the basic system shown in FIG. 8;

FIG. 15 is an explanatory diagram showing an example of a valve sequence for operating the basic system shown in FIG. 9;

FIG. 16 is a model diagram of a compact simulator for performing a pulse-like opening / closing operation test of an automatic valve by a “pulse flow control method” (PF).

FIG. 17 is a graph showing a temporal change of a differential pressure (ΔP) in an adsorption tower when a test is performed using the small simulator shown in FIG. 16;

[Explanation of symbols]

DA dry air A, B, C, D adsorption tower a, b adsorbent AR feed air (pressurized dry air) D _A, D _B drying tower Ex pressure energy recovery means V bypass valve O ₂ oxygen product N ₂ product nitrogen HN ₂ High purity nitrogen WA Exhaust air WN Exhaust nitrogen 1 Pump 2, 4, 5a, 5b, 5c, 6, 6a, 6b, 6c,
7, 7a, 7b, 8, 9a, 9b, 9c Pipe line 3 Pretreatment device 5 Separation device (or system) 27, 28 Automatic product removal valve 10 Vacuum pop 11a to 17a, 11b to 17b, 14c, 15, 1,
8, 18a, 18b, 20a to 20e, 19 to 21, 2
1a to 25a, 21b to 25b, 21c to 25c, 26
a to 26d, 31a to 34a, 31b to 34b, 31c
~ 34c, 31d ~ 34d, 35a, 35b, 36a,
36b Automatic (open / close) valve

Claims (18)

[Claims] 1. A poorly adsorbable component (A) and an easily adsorbable component (B)
In a pretreatment device, water, carbon dioxide, and other easily condensable gases, which are smaller in amount than the component (A) and component (B) contained therein and have extremely high adsorptivity, are removed in advance by using a pretreatment device. After that, one end (inlet end) to the other end (outlet end) of the adsorption tower of the adsorption separation system including at least two adsorption towers filled with an adsorbent capable of selectively adsorbing the component (B) in the form of a column or a layer. A gas bulk separation method for obtaining the component (A) and / or the component (B) by passing through to the other end (exit end) )), Wherein the component (A) and / or the component (B) are obtained as a product alternately at regular time intervals with low power consumption and high overall efficiency. The raw material mixed gas is passed to the inlet end of the adsorption tower, the pressure in the column is increased from intermediate pressure to the maximum operating pressure, and the component (B) in the raw material mixed gas is selectively adsorbed. Component (A) and / or a gas rich in component (A) are taken out from the end (outlet end). While the raw material supply is continued, the component (A) and / or the gas rich in the component (A) are taken out from the outlet end near the maximum operating pressure. Stop supplying the raw material, depressurize this adsorption tower in the co-current direction,
The depressurized gas passes through the inlet end of another adsorption tower that is close to the pressure during the same circulation operation and that is increasing in pressure. The depressurization is continued, and the gas released and / or sucked from the adsorption tower is released to the atmosphere, recovered to another adsorption tower, or the component (B) product And take it out of the system. A gas rich in component (A) and / or component (A) is introduced as a purge gas in a co-current direction from another adsorption tower in the same circulation operation to the adsorption tower under the minimum operating pressure, and the components ( B) is replaced by component (A), and components (B) and / or
Alternatively, a gas rich in the component (B) is taken out from the outlet end of the adsorption tower. After the above operation, the gas from another adsorption tower whose pressure is approximated and whose pressure is decreasing during the same circulation operation is passed to the inlet end, and the pressure is increased to the intermediate pressure of the operation. 2. The method according to claim 1, wherein the step is performed while continuing to supply the raw material mixed gas. 3. The method according to claim 1, wherein the step, the step of reducing the pressure of the step, and the step of increasing the pressure of the step are performed stepwise. 4. The method according to claim 1, wherein the raw material mixture gas is air and the product gas is at least 90% oxygen and / or at least 90% nitrogen. 5. The method according to claim 1, wherein the adsorbent is a zeolite-based molecular sieve material having a selective nitrogen adsorption. 6. The method according to claim 1, wherein the adsorption separation system comprises two adsorption columns. 7. The method according to claim 1, wherein the adsorption separation system comprises three or more adsorption columns. 8. The process according to claim 1, wherein the effluent gas of the process is supplied to another adsorption column as a purge gas of the process, and the component (A) of the process is converted into a product. 9. The method according to claim 1, wherein the effluent gas of the process is supplied to another adsorption tower as a purge gas of the process, and the component (A) of the process is converted into a product. 10. The method according to claim 1, wherein the component (B) sucked by the co-current depressurized gas and / or the pump in the step is a product. 11. A pretreatment tower filled with a pretreatment adsorbent selected from silica gel, activated carbon, alumina gel, activated alumina, and zeolite is provided in the adsorption separation system, and the step and the pressure reduction and / or purge discharge gas in the step are reduced. 2. The method according to claim 1, wherein a part of the gas is supplied as a purge gas for regeneration of the pretreatment tower. 12. An active ingredient in the gas discharged from the adsorption tower in step (1), [Component (A) when the target product is component (A), and component (B) when the target product is component (B)]. 2. The method according to claim 1, wherein the water is recycled to another adsorption tower in the same system via a pump. 13. An adsorption / separation system composed of three or more columns, wherein the individual operation of connecting two adsorption columns is directed to two adsorption columns having an operating pressure approximation and a pressure difference from one adsorption column to another adsorption column. Utilizing a gas flow in the co-current direction to reduce the pressure of one adsorption tower and the pressure of another adsorption tower, and to perform a purge operation on the adsorption tower under the minimum operating pressure. The method of claim 7. 14. When connecting two adsorption towers in an adsorption separation system composed of two or more towers, the gas phase concentration distribution in the adsorption tower in which the pressure inside the adsorption tower is increasing is such that the component (A) is directed toward the outlet end. When the pressure in the adsorption tower is decreasing, the concentration of the gas phase in the adsorption tower is made rich toward the outlet end so that the component (B) becomes rich toward the outlet end. 2. The method according to claim 1, wherein the gas transfer rate is controlled so that there is no step between the inlet concentrations of the gas. 15. The component (B) in the process is once collected in an intermediate tank, and prior to the process, the component (B) in the intermediate tank is recirculated to the inlet end of the adsorption tower via a pump, and Is replaced with the component (B), and thereafter, the gas in the adsorption tower and the component (B) in the adsorbent are suctioned by a pump, and the component (B) is recovered as a high-purity product. 10. The method according to 10. 16. The method according to claim 6, wherein two adsorption columns are connected in parallel in a two-column adsorption / separation system to equalize or partially equalize the pressure. 17. The method according to claim 1, wherein the pressure reduction in the step is performed through a pressure energy recovery means such as an expansion engine, and the pressure energy is recovered as electric and / or mechanical energy. 18. In a simulator test for transferring gas by connecting two adsorption towers having a pressure difference through an automatic on-off valve, the open time (△ ti) of the automatic on-off valve is determined. As a parameter, the time (t) change of the differential pressure (ΔP) between the inlet end and the outlet end of the downstream adsorption tower is measured and plotted (vertical axis: ΔP, horizontal axis: t). △ ti when the figure is sine wave or sine wave approximation wave type
Is the pulse time and the value obtained by subtracting △ ti from the half-wavelength width is △ Zi
And the amount of gas passing through the automatic on-off valve (Vi)
Is defined by the following equation (1): Δt ₁ (open) −ΔZ ₁
(Closed)-Δt ₂ (Open)-ΔZ ₂ (Closed) ...
The (open)-△ Zi (closed) valve opening / closing sequence (valve opening time-time relationship) requires and sufficient gas movement amount (ΣVi) and gas movement speed [Σ
2. The method according to claim 1, wherein Vi / (Σti + ΣZi)] is controlled. (Equation 1)