JPS59112822A - Concentration of difficultly adsorbable component in gas - Google Patents

Abstract

PURPOSE:To maintain the purity of product gas to a high level even if a desorbing stage is switched over to an adsorbing stage, by effectively removing an easily adsorbable component from an adsorbing tower at the point of time when the desorbing stage is finished. CONSTITUTION:Figure (a) shows such a state that a first adsorbing tower 1A is in an adsorbing stage and a second adsorbing tower 1B is in a desorbing stage. Stock gas is supplied into the adsorbing tower 1A and, during a time when said gas is moved to the top part from the bottom part in the adsorbing tower 1A, the adsorptive separation of an easily adsorbable component is performed by an adsorbent. In figure (b), after the adsorbing stage of the adsorbing tower 1A and the desorbing stage of the adsorbing tower 1B are finished, the adsorbing tower 1A is in the desorbing stage and product gas is flowed into the adsorbing tower 1B from the top part thereof while the stock gas flowed thereinto from the bottom part thereof to bring the adsorbing tower 1B to an equilibrium stage. After the equilibrium process is completed, the adsorbing tower 1B is transferred to the adsorbing stage for passing the supplied gas through the adsorbing tower B and, at the same time, the exhausion in the adsorbing tower 1A is started and desorption due to pressure reduction is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for concentrating difficult-to-adsorb components in a gas by alternately using two adsorption towers.

When the easily adsorbed components in the gas are adsorbed and removed to concentrate the poorly adsorbed components, the adsorption capacity of the adsorbent decreases with rJ as the adsorption of the easily adsorbed components progresses.
It is necessary to stop the use of the adsorbent after adsorption of the coulometric amount to stop the desorption, and if continuous concentration treatment is to be carried out, two adsorption towers are used alternately. In such an adsorption apparatus with 12 towers installed in parallel, the raw material gas is supplied to the adsorption tower under pressure in the adsorption process, and the pressure inside the adsorption tower is usually reduced in the desorption process to remove the adsorbed components. It is. However, the easily adsorbed components that are desorbed from the adsorbent by the reduced pressure remain in the adsorption tower 2 even at the end of the desorption process, so when the raw material gas is introduced in the next adsorption step t'1fc, the easily adsorbed components This causes the purity of the product gas to decrease.

This invention effectively removes the easily adsorbed components from the adsorption tower at the end of the desorption process, thereby maintaining the purity of the product gas at a high level even when switching from the desorption process to the adsorption process.
The purpose of this invention is to provide a method for concentrating difficult-to-adsorb components that can be ground into fibers.An example of the steps of the method of the present invention will be explained below with reference to the drawings. In Figure 1, ladle number 1A
1B represents the first adsorption tower, and 1B represents the second adsorption tower, each of which is filled with an arbitrary adsorbent. The raw material gas containing difficult-to-adsorb components and easy-to-adsorb components is passed from blower 2 through valve ViA to adsorption tower 1A≦:, 1 valve is to valve ViB.
The adsorption tower iB
I have two tJs. The valve VIA and ViB are controlled on the paternal side (=opening/closing control f+, this 1) according to a predetermined sequence.
(2) Therefore, the adsorption process and the desorption process that go to the adsorption tower 1A and 1B are the paternal (two choices). (1) If the adsorption tower 1A is in the adsorption process, the raw material gas passes through the valve ViA The gas is supplied from the bottom of the column 1A, and the adsorption separation of the easily adsorbed components is carried out under normal pressure 1fc.The poorly adsorbed components that have not been subjected to the primary adsorption are passed through the valve V7A to a fixed volume. Feedback tank 3C: Once entered, the product gas is taken out to the outside through check valve V5 and valve ■6. Adsorption tower 1B via Kurub ViB
The poorly adsorbed components that crawled to the top of the column are sent to the bottom of the column, and the components that are difficult to adsorb are sent to the bottom of the column.
Feed through B/cutting 3 (second lead).

First, in the desorption process of the adsorption tower 1A, switch) (switching) (lube 8) to the adsorption tower 1A side, and 7 (close loop v7A,
In order to reduce the pressure inside the adsorption tower 1A by the action of the vacuum pump 50, the desorption process of the adsorption tower 1B is performed by switching the switching valve V8 and closing the valve V7B. (= Therefore, in the same way, the ladle 1 and the desorption gas are necessary, and the n is collected 6.

The continuous concentration operation for difficult-to-adsorb components is shown in Figure 2 (a) and (b).
).

(c) I: Ladle in the indicated fc order. 1. Figure 2 (a
) indicates a state where the first adsorption tower 1A is in the adsorption process and the second adsorption tower 1B is in the desorption process≦2. The raw material gas passes through the blower 2ρ) and the valve v1A into the adsorption tower 1A. The adsorption separation of the components, that is, the concentration of the poorly adsorbed components, is omitted, and the poorly adsorbed components are temporarily stored in the feedback tank 3 via valve V7A. 6 and then taken out as a product gas.

With the valve V7B closed and the switching valve ■8 switched to the adsorption tower 1B side, the inside of the adsorption tower 1B is evacuated by the action of the vacuum pump 50 and the pressure is reduced, and the adsorbent from the previous adsorption process is removed. (The desorption of easily adsorbed components is reduced.

FIG. 2(b) shows the adsorption process of adsorption tower 1A and adsorption tower I.
After the desorption step of B is completed, the adsorption tower 1A enters the desorption step 1, and the adsorption tower 1B enters the adsorption step (n = indicates a certain state. Adsorption of the adsorption tower 1A. At the same time as the process ends (:, the switching valve v8 is switched from the adsorption tower 1B side to
When switching to the A side and valve V1A is closed, 1.
2. Valve ViB and V7B open. Due to ζ1, the internal pressure of the adsorption tower 1B is reduced to tJ during the desorption process, and the product gas in the feedback tank 3 is released from the top,
The flfc raw material gas sent from the blower 2, which is
Do two in a row.

After the equilibrium step is completed, an adsorption step ζ in which the n* gas supplied from the blower 2 through the valve V1B passes through the adsorption tower 1B.
: At the same time as switching valve ■8 is switched at the completion of the 1-hole equilibrium step (=, exhaustion in the adsorption tower 1A begins, desorption due to reduced pressure starts from the time when valve V7A closes). Ladle (Figure 2 (C)).

Note that the desorption process of the adsorption tower 1A and the adsorption tower 1. When the adsorption step B is completed, the switching operation of the switching valve v8 and the switching operation of the valve VI
The opening operation of valves A and V7A and the closing operation of valve V1B are almost simultaneous (2). (a)
The State of Sound: Return. This operation is repeated to achieve continuous concentration.

In FIG. 1, the dotted lines in the adsorption towers IA and iB indicate that the upper portion of the π portion is the adsorbent and the lower portion is the pretreatment agent, but the pretreatment agent may be omitted.

Adsorption in the adsorption tower 1A and 1B can be carried out at approximately the same pressure as atmospheric pressure (C), but depending on the fences of the adsorbent used or the fences of the easily adsorbable components to be adsorbed, For example, when activated carbon is used as an adsorbent to remove CO2 from gas, a strong effect can be obtained under normal pressure, but natural tuff It has been confirmed through experiments that N2 in the air is removed using stones (when concentrating 02), the adsorption is reduced under a pressure of about 1.5 to 9/cm2. 2 Adsorbents for such N2 adsorption include -fX shown in Table 1.
In addition to natural tuff (mordenite) with a line diffraction pattern,
Examples include commercially available adsorbents such as semi-synthetic zeolites, synthetic zeolites, and the like.

As adsorption towers 1A and 1B, (jzo-nso.

Five experiments were carried out in which 02 in the air was concentrated according to the method of the present invention using zeolite filled with odor at a packing density of 0.73. Other conditions were as follows.

Blower air supply volume: 4 m/aclimate vacuum pump displacement volume: l Q m 7 m The relationship between the f1fc product 02 concentration obtained in this experiment and the effective oxygen amount (EO2) is shown in Figure 3 (-1'E*Product 02 concentration and The relationship between the effective oxygen amount (EO2) and the vacuum pump displacement (VP) per tower is shown in Figure 4.
) can be calculated using the following formula.

χ: Concentration of product 02 y: Flow rate of product 02 As is clear from FIGS. 3 and 4, a high concentration of 02 can be obtained at a large flow rate.

n:1. ;84 figure (:!, EO2/2VP=1.0
(The 1 point is based on a typical example of a method that is usually performed using 3 columns (initial adsorption, final adsorption, and desorption).
Even with this invention method, which uses two towers, the product is 0 at normal pressure.
It is shown that an effect of 80% or more (0.8 point in the figure) can be obtained at the 80% point of 2!1 degrees.

Changing the number of adsorption towers from three to two means a reduction in the number of adsorption towers (=
In addition, since it provides the great advantage of reducing the number of pulps, the applicability of this invention is extremely high.

When the ifc adsorption is carried out under pressure, the EO□/2VPO value reaches approximately 0.95 at the point where the concentration of product 02 is 80%, indicating that tJ is almost inferior to that in the case of three columns. There are n.

As described above (=according to the present invention, when concentrating difficult-to-adsorb components in the raw material gas by repeating adsorption and desorption alternately in two adsorption towers, the inside of the adsorption tower (:,
By introducing the raw material gas from the bottom of the column C:, and by introducing the product gas from the feedback tank storing the product gas to the top, the pressure inside the adsorption tower is balanced from both the bottom and top. Therefore, difficult-to-adsorb components can be efficiently obtained at high concentrations.

[Brief explanation of drawings]

FIG. 1 is a system diagram of the equipment used in the present invention, and FIGS. Figure 3 is a graph showing the relationship between product 02 concentration and cumulative amount of effective acid, and Figure 4 is product 02!1.
3 is a graph showing the relationship between degree of performance and performance ratio. 1A, 1B...Adsorption tower, 2...Blower, 3...
Feedback tank, 5... vacuum pump. Patent applicant: Industrial Development Research Institute No. 1
Figure 2 (a) (b) Writer (C) Procedural amendment (voluntary) 1. Display of the case Patent Application No. 222432 of 1982 2, Title of the invention Method for concentrating difficult-to-adsorb components in gas 3, Person making the amendment Relationship to the case Patent applicant address Name Name Nakane) Industrial Development Research Institute 4. Agent address: 2-11-1 Yoyogi, Shibuya-ku, Tokyo 151
No. 2 - Kimura Building Floor 5, Date of Amendment Order Showa Year, Month, Day (Despatch) As shown in the attached sheet 8, Contents of Amendment (1) "Pulp V7A Co. R Pulp V, 1 A, V 7 A, J. (2) [Pulp V'7BJ on page 4, line 11 is corrected as "pulp V1B, V7BJ." (3) Page 5, line 6 of the same ``Pulp V7BJ [Pulp V
Correct with IB and V7BJ. (4) “Pulp V1A” on page 5, lines 16 to 17
” is corrected as [pulp V 1A, V 7 AJ. (5) Correct “beginning... to be done” in lines 7 to 8 of page 6 to “beginning”. (6) “Pulp V1B
Return to... "The closing operations of pulps V1B and V7B are performed almost simultaneously, and after going through an equilibrium process in which 1A and 1B of bl are reversed, the adsorption tower 1A enters the adsorption process. (7) Figure 4 of the drawings will be revised as shown in the attached sheet.

Claims (1)

[Claims] There is an adsorption process in which the material is fed into two adsorption towers filled with selective adsorbent, and the easily adsorbed components are concentrated, thereby concentrating the difficult to adsorbed components. In the previous adsorption step, easily adsorbed components were demigrated under reduced pressure.
The desorption process is called an adsorption tower (a method of concentrating difficult-to-adsorb components in a gas that is alternately depleted using two adsorption towers).The product taken out from the adsorption tower during the adsorption process is collected in a feedback tank with a predetermined volume. (2) Temporarily stored, the desorption process is completed, and the internal pressure is reduced. Therefore, a method for concentrating difficult-to-adsorb components in a gas is characterized by adding an equilibrium step of balancing the pressure in the adsorption tower after the desorption step.