JPH0443696B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention mainly relates to a separation agent comprising a novel zeolite composition suitable for separating, purifying, or concentrating oxygen and nitrogen gas from a gas mixture comprising oxygen and nitrogen gas by an adsorption method. The present invention relates to a method of manufacturing a molded body. [Object of the Invention] The object of the present invention is to provide a separation method comprising a zeolite composition of Y-type zeolite, A-type zeolite, and An object of the present invention is to provide a method for producing a molded product of a drug. [Prior art] When separating and purifying oxygen and nitrogen gas by adsorption method, A-sized particles with pores of around 5 Å that have molecular sieve action are used.
type zeolites are widely used. Commercially available MS-5A is exemplified as a typical adsorbent. [Structure of the Invention] In order to improve the separation and concentration of the above-mentioned gases, the present inventor conducted research to increase the adsorption and desorption rate of mainly oxygen and nitrogen gases to zeolite-based adsorbents, and found that the pore diameter Approximately 8Å
A composition in which sodium-type Y-type zeolite is replaced with a certain amount or more of divalent metal has a higher N ₂ /O ₂ adsorption ratio than known zeolites, and also has a higher gas adsorption and desorption rate. Therefore, it has been found that the divalent metal-substituted zeolite composition is extremely effective in separating and concentrating the above-mentioned oxygen and nitrogen gases based on the adsorption method. Also,
A zeolite-based composition as a separating agent, which is made by substituting X-type, Y-type, and A-type zeolites with divalent metal ions, is mixed with an appropriate binder, molded, and thermally activated to form a molded body. It has been found that various advantages arise in the production of and the molded articles obtained. First, an oxygen and nitrogen separating agent made of a dimetal substitution type zeolite composition effective for separating, purifying, and concentrating oxygen and nitrogen gases will be described. This separation agent converts the ion-exchangeable sodium of Y-type zeolite into divalent metal ions (M ²⁺ ).
It is composed of the following active zeolite composition suitable for the separation, purification, and concentration of oxygen and nitrogen gases obtained by substitution with That is, it is made of a zeolite composition in which the sodium contained in the Y-type zeolite is ion-exchanged with calcium in an equivalent fraction of 0.8 or more, strontium in a 0.9 equivalent fraction or more, or barium in a 0.7 equivalent fraction or more. . NaCaY (≧0.8) NaSrY (≧0.9) NaBaY (≧0.7) However, the above Y represents Y-type zeolite, and the value in parentheses indicates the equivalent fraction of divalent metal () in the zeolite solid phase. (Total amount of ion-exchangeable metals in the zeolite solid phase: +=
1 equivalent fraction). The Y-type zeolite-based composition substituted with a divalent metal, which constitutes the above-mentioned separation agent, is produced by ion-exchanging Y-type zeolite with a pore diameter of approximately 8 Å using a water-soluble solution of divalent metal chloride, nitric acid, etc. from room temperature to high temperature (20~
90°C). mentioned above
The optimal content of divalent metals in the three types of zeolite solid phases, NaCaY, NaSrY, and NaBaY, is as follows. That is, ≧0.8 for NaCaY compositions, ≧0.9 for NaSrY compositions, and ≧0.7 (equivalent fraction) for NaBaY compositions are required to achieve a high separation efficiency for oxygen and nitrogen gases. Between the above lower limit equivalent fraction and the saturation value (=1), when air components are separated by the GC method using activated products of the three types of zeolite compositions mentioned above, oxygen and nitrogen gas The peaks are completely separated, and the S, Q, and R values associated with GC evaluation are
An improvement was observed compared to these values for NaY. It was also confirmed that the adsorption and desorption of air components to the three types of NaMY compositions described above were carried out extremely quickly and under favorable conditions. Furthermore, as the value decreases below the above adjustment value,
The S, Q, and R values tend to become smaller. Based on this reason, the numerical values of NaMY in the three types of composition were limited as described above. Next, the present invention will be explained. The present invention focuses on the separation, purification, and purification of oxygen and nitrogen gases.
The present invention also relates to a method for forming a divalent metal-substituted zeolite composition that is effective for concentration. That is, X
Inorganic and/or organic bonding to a powder or small granular product of a zeolite composition in which the sodium contained in type, Y type, and /A type zeolite is ion-exchanged with an alkaline earth metal at an equivalent fraction of 0.7 or more. Wet blending is performed in the presence of the agent to obtain a homogeneous mixture, which is then molded into a predetermined shape, the resulting molded product is subsequently dried, and finally fired at a temperature range of 400 to 580°C. A method for producing a molded body of an activated zeolite composition, characterized by: Preferred inorganic binders used in the molding of the present invention include bentonite, diatomaceous earth,
Examples include colloidal substances such as kaolin, colloidal silica, and colloidal alumina. On the other hand, preferred organic binders include crystalline cellulose such as methylcellulose, carboxymethylcellulose, and hydroxyethylcellulose, and molasses. During wet molding, the above-mentioned inorganic and organic binders may be used alone or in combination. The amount of water required in the mixing process of the present invention is controlled by the physical properties of the divalent metal-substituted zeolite composition as the raw material, but in normal cases, the amount of water required is 20
A moisture content of ~50% is a suitable range. Next, the amount of binder used will naturally vary depending on the type of binder and the physical properties of the molding material, but if only an inorganic binder is used, an appropriate amount ranges from 6 to 36% based on the zeolite composition material. On the other hand, when using only an organic binder, the appropriate amount ranges from 1 to 5%. By using the above amounts of water and binder, an easily moldable mixture is obtained which can be molded into spheres,
It can be processed into molded products in columns, pellets, cylinders, plates, honeycombs, and other shapes. Next, the obtained molded body is dried at around 100°C to adjust its shape, and then fired in a temperature range below the thermal decomposition initiation temperature of the zeolite composition to release oxygen and nitrogen gases according to the present invention. A molded body of a divalent metal-substituted zeolite composition suitable for purification and concentration is obtained. The above firing temperature varies depending on the type of the zeolite composition of the present invention used, but in general, 400 to 580°C is appropriate, and 450 to 560°C is the preferred firing temperature range. Hereinafter, the effects of using the above-mentioned binder and setting the moisture content of the mixture and the calcination temperature within the above-mentioned ranges are as follows: () When producing a molded body made of a zeolite-based composition, When an inorganic binder such as bentonite or diatomaceous earth is used, it strengthens the bond between the zeolite fine particles.
In addition, the above-mentioned inorganic binder is thermally stable and does not adversely affect the inherent properties of the zeolite even when the molded body is fired at the temperature of 400 to 580°C, so that it can be obtained. It has the advantage of having little negative effect on the gas adsorption properties of the final product. () By using the above-mentioned organic and/or inorganic binders, a uniform wet mixture of zeolites can be easily obtained. Furthermore, by using an organic binder, the wet mixture of zeolite can be molded very easily. () If an organic binder is used, the organic binder will be completely thermally decomposed when the molded body is fired in the above-mentioned temperature range, so the inherent adsorption capacity of zeolite will not be reduced by dilution with the binder. has advantages. () If an inorganic binder and an organic binder are used together, the amount of the inorganic binder used can be reduced compared to the case where only the inorganic binder is used. () As mentioned above, an inorganic and/or organic binder is used and the moisture content in the mixture is 20%.
Set the range to ~50% and further increase the firing temperature to 400
By setting the temperature in the range of ~580°C, the N ₂ /O ₂ adsorption ratio of the resulting molded body exhibits an extremely high value, making it possible to manufacture a molded body with excellent selective adsorption properties. () By using the binder as described above and setting the moisture content and firing temperature within the above range, the adsorption rate and desorption rate of nitrogen or oxygen of the obtained molded product are high. () The molded product obtained has a large specific surface area and is porous, thereby increasing the selective adsorption of oxygen and nitrogen. () The mechanical strength of the molded product obtained is sufficiently high, and there is no breakage or wear, making it suitable as an adsorbent packed into an adsorption tower. In the present invention, the preferred composition of the zeolite composition to be mixed with the binder is limited as described above when Y-type zeolite is used as the starting material. Furthermore, in the present invention, as the zeolite composition, those having the following composition using type X zeolite or type A zeolite as a starting material can also be suitably used. (1) Sodium contained in X-type zeolite is
A zeolite composition ion-exchanged with calcium, strontium and/or barium in an equivalent fraction of 0.8 or more. NaCaX (≧0.8) NaCaX (≧0.8) NaSrX (≧0.8) (2) A zeolite composition in which sodium contained in type A zeolite is ion-exchanged with calcium at an equivalent fraction of 0.9 or more. NaCaZ (≧0.9) However, the above X and Z represent type X zeolite and type A zeolite, respectively. Using an aqueous solution of water-soluble divalent metal chloride, nitrate, etc., an ion exchange reaction is carried out on X-type zeolite (NaX) with a pore diameter of about 10 Å with divalent metal ions at room temperature to high temperature, e.g. 20 to 90°C. NaCaX with a pore size smaller than 10 Å, obtained by
In each case, the content of divalent metal in the three types of zeolite compositions, NaSrX and NaBaX, is at least 0.8 equivalent fraction or more, which increases the separation efficiency of oxygen and nitrogen gases by the selective adsorption method. It is also necessary for The N ₂ /O ₂ adsorption ratio for the above three thermally activated products with such compositions is:
In either case, there is an advantage of an improvement of 5 to 33% compared to that of NaX. Furthermore, the gas chromatographic characteristics of the X-type zeolite substituted with the above three types of divalent metals are more improved than those of NaX. That is, the above three types
When air components are separated by gas chromatography (GC) using NaMX-activated products (≧0.8 equivalent fraction), the chromatographic separation of oxygen and nitrogen gas obtained is different from that when using NaX-activated products. The relative resolution of the gas chromatograph was improved in a more favorable direction by comparison.
(S), relative sharpness (Q), and resolution (R), all of these values were found to be significantly lower for the former three types of divalent metal substitutes than for the latter NaX. It was confirmed that the amount increased significantly. The above S,
Evaluation of Q and R was done by WLJons, R.Kieselbach,
Anal.chem., 30 , 1590 (1958).
This tendency of increasing S, Q, and R values is caused by the separation or concentration of oxygen and nitrogen gases from air components etc. using the adsorption method when activated products of the three types of NaMX (≧0.8) are used. By using it as a separation agent, not only can the amount of separation agent used be reduced compared to the amount required for known separation agents, but it also has the effect of significantly shortening the time required for the adsorption process and regeneration process of the adsorption bed. ing. In other words, by using NaMX having the above-mentioned composition, there is an advantage that the above-mentioned target gas can be economically obtained by the adsorption method. In the present invention, the above three types
In all NaMX compositions, the equivalent fraction is limited to ≧0.8. = S, Q, R in the equivalent fraction range of 0.8 to 1.0
The values are excellent compared to those of NaX,
On the other hand, it was observed that the S, Q, and R values tended to gradually decrease as the values decreased below the above lower limit. Due to these points, in the present invention, NaMX
In the three types of zeolite compositions consisting of: Next, a case will be described in which a zeolite composition using type A zeolite as a starting material is used in the present invention. Pore size obtained by performing an ion exchange reaction on type A zeolite with a pore size of approximately 4 Å using a solution of water-soluble calcium chloride, nitrate, etc. at room temperature to high temperature (20 to 90°C). 5
The optimal amount of calcium in the solid phase for NaCaZ zeolite compositions is ≧0.9 equivalent fraction. NaCaZ
Within the range of = 0.9 to 1.0 equivalent fraction, N ₂ /
The O ₂ adsorption ratio (B・E・T method, 760 mmHg; 25° C.) tends to increase slightly in proportion to the calcium content, but this ratio is within the range of 31.8 to 3.3. of the NaCaZ composition of the present invention (≧0.9 equivalent fraction)
The N ₂ /O ₂ adsorption ratio is calculated using commercially available molecular sieves.
MS-5A (powder) N ₂ /O ₂ = 3.0 (760 mmHg; 25
It has the characteristic that it is 6-10% higher than that of ℃). This fact is true when using the naCaZ (≧0.9) composition of Reference Example 3 and separating or concentrating oxygen or nitrogen gas from air as a raw material gas by the adsorption method. This clearly shows that the difference in properties can be exhibited and that the target gas can be easily obtained at a higher rate compared to known adsorbents of the same type. Reference Example 1 Reference Example 1 relates to a production example of a NaMY-type zeolite composition obtained by replacing ion-exchangeable sodium of Y-type zeolite (NaY) with a divalent metal (M ²⁺ ). As described in Table 1, using NaY as the starting material,
NaSrY (≧0.9) having the composition indicated by performing ion exchange by batch method 3 to 4 times using 2MSrCl ₂ , 1.8MBaCl ₂ , and 2MCaCl ₂ aqueous solution,
NaCaY (≧0.8) and NaBaY (≧0.7 equivalent fraction) zeolite compositions were prepared. The starting material NaY zeolite for this reference example is _1.09Na2 .
_A dry powder with _a chemical composition _{of Al2O3.3.98SiO2.XH2O} was used. The specific surface area (SSA) of this activated powder was 937 m ² /g. Reference Example 2 Next, Reference Example 2 shows an example of producing a zeolite composition using type X zeolite as a starting material, which can be used in the present invention. This reference example converts the ion-exchangeable sodium of type X zeolite (NaX) into a divalent metal ion (M ²⁺ ).
NaCaX suitable for the separation, purification or concentration of oxygen and nitrogen gases obtained by displacement with
(≧0.8), NaSrX (≧0.8), and NaBaX
(≧0.8 equivalent fraction) of an active zeolite composition. Starting material NaX
The type of zeolite is 1.00Na ₂ O・Al ₂ O ₃・
A dry fine powder with a chemical composition of 2.29SiO ₂ .XH ₂ O was used. This is thermally activated and the specific area (S.
SA) was measured and obtained 838 m ² /g. NaX above
On the other hand, as shown in the processing conditions in Table 2,
Ion exchange was performed in batches using 2M SrCl ₂ , 1M BaCl ₂ , and 2M CaCl ₂ aqueous solutions at 60°C for 4 to 30 minutes.
Three to four runs were carried out keeping under stirring for 5 hours to convert to NaSrX, NaBaX, and NaCaX, respectively. Final processing using the batch method has been completed.
NaMX was centrifuged and then washed with water. Washing with water was carried out until chlorine ions disappeared. Finished washing with water. The NaMX composition was dried at 100-110°C and then made into a fine powder. Zeolite composition obtained according to this reference example
The composition and yield of NaMX are listed in Table 2. If the zeolite composition obtained in Reference Example 2 is thermally activated into an anhydride according to the present invention, a separating agent suitable for separating and concentrating oxygen and nitrogen gases can be obtained. Reference Example 3 Reference Example 3 is a production example of a zeolite-based composition using type A zeolite as a starting material, which can be used in the present invention. That is, type A zeolite (NaZ)
NaCaZ suitable for separation, purification and concentration of oxygen and nitrogen gases obtained by replacing ion-exchangeable sodium with calcium ions
(≧0.9 equivalent fraction) of an active zeolite composition. In this example, the starting material NaZ zeolite was 1.02Na ₂ O.
A dry powder with a chemical composition of Al ₂ O ₃ .1.92SiO ₂ .XH ₂ O was used. The specific surface area (SSA) of this activated powder was 665 m ² /g. The ion exchange in this example was performed using a 2.5M CaCl ₂ aqueous solution and holding it at 60°C for 4 hours under stirring four times to obtain a NaCaZ composition having the composition shown in Table 3. It was done. The thermally activated product had the characteristics described below and was found to be excellent as an oxygen and nitrogen separating agent. _Table 4 shows the N ₂ /O ₂ adsorption ratio of the zeolite composition obtained in Reference Example ₂ . The table shows the improvement compared to . Comparative example 1
The N ₂ /O ₂ adsorption ratio of the activated NaX product is 2.81 (760 mm
Hg; 25°C), but the N ₂ /O ₂ adsorption ratio of the activated product of the NaMX type zeolite composition of Reference Example 2 obtained by these ion exchanges is 2.94 ~
3.75 and therefore the above adsorption ratio is
It was found that NaMX provides a 5-33% improvement compared to NaX. Furthermore, the N ₂ /O ₂ adsorption ratio of the activated product of NaCaZ (=0.9165 equivalent fraction) of Reference Example 3 is 3.18,
On the other hand, that of the same type of commercial product MS-5A (Comparative Example 2) is
It is within the range of 2.9 to 3.0. Therefore, the former shows a 6 to 10% higher adsorption ratio than the latter. The above fact clearly indicates that the activated products of the zeolite compositions of Reference Examples 2 and 3 can further increase the separation efficiency when used as an adsorbent for the purpose of separating and concentrating oxygen and nitrogen gases. [Example] Next, specific aspects of the present invention will be explained based on Examples, but the present invention is not limited to the Examples unless the gist thereof is exceeded. This example relates to a method for producing a molded body of an activated zeolite composition suitable for separating, purifying, and concentrating oxygen and nitrogen gases. The raw material for the zeolite composition for molding was a dry powder of NaCaZ composition (=0.9186;=0.0814 equivalent fraction) produced according to the method of Reference Example 3.
60Kg was used. 13.8 kg of bentonite fine powder and 1.2 kg of methyl cellulose were added to the above zeolite composition material, and 2 kg was added using a V-mixer.
A mixture was prepared by mixing for 30 minutes. next,
Add water to the above mixture and mix for 3 hours.
It was conducted for 50 minutes. Moisture in the mixture at the end of mixing is 35
Retained at ~36%. Next, the mixture was wet-molded to form 1/16" pellets, and the resulting 1/16" pellets were dried at 100 to 110°C. After further adjusting the length of the dried pellets using a flasher, the above pellets were finally calcined at 530-550°C for 4.5 hours to obtain a molded body of an active zeolite composition. In this molding, the sintering agent is used as 1/16" pellets.
45Kg was obtained. In addition, 1/16″ obtained in this example
The physical properties of the molded product were as follows. Average strength of 1/16″ pellets: = 3.04 Kg/pellet Apparent density of 1/16″ pellets: = 1.308 SSA of 1/16″ pellets: 569 m ² /g N/O adsorption ratio of 1/16″ pellets: 3.17 (760 mmHg; 25°C) The N ₂ /O ₂ adsorption ratio of the calcined 1/16″ pellets obtained in this example was 3.17 as described above;
The N ₂ /O ₂ adsorption ratio of commercially available MS-5A, 1/16" pellets is 2.93. As can be seen from this, the 1/16" pellets obtained in this example are suitable for separating oxygen and nitrogen gas. It is clear that it is more effective in concentration than commercially available products. In addition, this molded product, NaCaZ,
A GC test was conducted using crushed 1/16" pellets with a particle size distribution of 40 to 60 mesh.
It was found that the oxygen and nitrogen peaks in air were completely separated, and the obtained SQR values were both excellent. Next, the NaMX type zeolite composition obtained in Reference Example 2 and the NaMY type zeolite composition obtained in Reference Example 1 were molded in exactly the same manner as in the above example, and finally calcined to 1/2 16″ pellets were prepared. Furthermore, NaX (1.00Na ₂ O・Al ₂ O ₃・2.29SiO ₂・
XH ₂ O) powder and NaY (1.09Na ₂ O・Al ₂ O ₃・3.98SiO ₂・
XH ₂ O) powder was molded in the same manner as in the example, and the molded body was finally fired at 530 to 550°C for 4.5 hours to form activated NaX・1/16″ pellets and NaY・1/ 16″ pellets adjusted. Prototyped NaSrX・1/16″ pellets, NaCaX・1/16″ pellets, NaX・1/16″ pellets, NaSrY・
1/16″ pellets, NaBaY・1/16″ pellets,
Seven types of molded bodies, NaCaY 1/16" pellets and NaY 1/16" pellets, were crushed to coarse particles, then classified, and those in the particle size range of 40 to 60 mesh were used as samples for GC testing. . For the GC test, use a gas chromatography filled tube (3φ x 2000
mm) of the above zeolite composition (40 to 60
8 to 9 g of mesh was filled. After aging the column at 260°C for 15 hours, air was used as the test condition under the GC measurement conditions listed in Tables 5 and 6, and helium was used as the carrier gas.
I did a GC test. As shown in Table 5, in the GC test using activated NaSrX and NaCaX molded products, when air was used as the test gas, the oxygen and nitrogen peaks were separated under favorable conditions, and these two It was observed that the S, Q, and R values obtained using the molded body of Comparative Example 1 were increased compared to these values of the NaX molded body of Comparative Example 1. Carrier gas flow rate
S when using NaSrX molded body even if it increases by 4.5 times,
The Q and R values remained almost unchanged. Furthermore, the S, Q, and R values when using the NaCaX molded body show a slight tendency to decrease even if the flow rate of the carrier gas is increased by three times. These facts indicate that the NaMX (M=Sr, Ca) molded body is suitable as an adsorbent for separating and concentrating oxygen and nitrogen gases. Table 6 relates to GC tests using activated NaMY molded products. Under the indicated GC measurement conditions, the S, Q, and
It was found that the and R values were superior to those of Comparative Example 3 when the NaY molded body was used.
Adsorption and desorption of oxygen and nitrogen gases on NaMX-type adsorbents and NaMY-type adsorbents are performed more quickly than on known adsorbents, as seen from GC data. It is clear that the above-mentioned type of adsorbent has the characteristic of exhibiting high efficiency in the process of purification. In summary, the present invention provides seven zeolite compositions [NaMX, NaMY (M=Ca, Sr ,Ba)
and NaCaZ], and it is recognized that the adsorption method of the present invention will be widely used in the gas field.

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Claims (1)

[Scope of Claims] 1. Powder or small granules of a zeolite composition obtained by ion-exchanging 0.7 equivalent fraction or more of sodium contained in X-type zeolite, Y-type zeolite and/or A-type zeolite with an alkaline earth metal. at least one inorganic binder selected from the group consisting of bentonite, diatomaceous earth, kaolin, colloidal silica, and colloidal alumina and/or at least one organic binder selected from the group consisting of crystalline cellulose and molasses. The mixture is wet-mixed with a binder, the moisture content in the mixture is maintained at 20-50%, the resulting mixture is molded, dried, and then fired at a temperature of 400-580°C. A method for producing a molded body of an oxygen and nitrogen separating agent made of a zeolite composition. 2. A method for producing a molded body of an oxygen and nitrogen separating agent comprising a zeolite composition according to claim 1, wherein the alkaline earth metal is calcium, strontium and/or barium. 3 Sodium contained in X-type zeolite is
A method for producing a molded body of an oxygen and nitrogen separating agent comprising the zeolite composition according to claim 1, which is ion-exchanged with calcium, strontium and/or barium at an equivalent fraction of 0.8 or more. 4 Sodium contained in Y-type zeolite is
The separation of oxygen and nitrogen from the zeolite composition according to claim 1, which is ion-exchanged with calcium in an equivalent fraction of 0.8 or more, strontium in a ratio of 0.9 or more, or barium in a ratio of 0.7 or more. A method for producing a molded product of the agent. 5 The sodium contained in type A zeolite is
A method for producing a molded body of an oxygen and nitrogen separating agent comprising the zeolite composition according to claim 1, which is ion-exchanged with calcium at an equivalent fraction of 0.9 or more.