JPS6077108A - Oxygen concentration pump - Google Patents

Abstract

PURPOSE:To provide an oxygen concentration pump having excellent selectivity to permeation of O2 and high heat resistance, and composed of an oxygen-ion conductive solid electrolyte containing ZrO2 and MF3 at specific ratios and represented by a specific general formula. CONSTITUTION:The raw material of an oxygen-ion conductive solid electrolyte represented by the general formula (ZrO2)100-x(MF3)x ( M is Y and X is 13-25, or M is Yb and X is 16-25; X is mol%) is prepared beforehand. The material is formed to a desired form and calcined. The obtained sintered material is mounted in a specific tube to obtain an oxygen-concentration pump. The pump is resistant to heat and has excellent selectivity to the transmission of O2.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an oxygen pump, and particularly to an oxygen pump using a novel substance that has high conductivity and thus has good permselectivity for oxygen.

Concentrating oxygen in the air or deoxidizing oxygen-containing gas using a partition wall (PI) that has selective permeability to oxygen is used, for example, in the medical field, food, etc.
Various proposals have been made in various fields such as chemistry and the electronics industry, and some of them have been put into practical use.As such diaphragms, for example, diaphragms made of organic polymers such as polyorganosiloxane are handled. Although the above and performance-F properties are said to be preferable materials, such organic polymer materials generally have drawbacks such as the need to provide a differential pressure across a diaphragm.

In contrast, a method has been proposed in which so-called stabilized zirconia stabilized with Y2O3, CaO, etc. is used as a diaphragm and voltage is applied to both sides of the diaphragm. Although this material has the advantage of having a certain degree of selective oxygen permeability and sufficient heat resistance, it is generally difficult to put this material to practical use.
Above 00°C.

Preferably, it is required to be placed in a high temperature atmosphere of 800°C or higher. Furthermore, since this type of material is put to practical use using electrodes, there are many disadvantages such as significant restrictions on the material when using 800' CC human high temperature, and the operation is complicated. .

As a result of various studies and examinations aimed at finding a material with such heat resistance that could improve the above-mentioned disadvantages, the inventor of wood discovered that a fluorinated oxide having a specific composition was found. It has been found that the above object can be achieved.

Thus, the present invention provides general formula (Zr02)100-"('
Provides an oxygen pump using an oxygen ion conductive solid electrolyte represented by MF3h (where M=Y and !=13 to 25. or M=Yb and x=16 to 25.X is mol%) There is something to do.

In the present invention, if the composition deviates from the above-mentioned range, the conductivity will be significantly lowered, the composition will be non-uniform, and the thermal shock resistance will be lowered, which is not practical.

When the composition is within the above range, the conductivity and sinterability are almost stable or constant, and the composition is sufficiently practical. From the viewpoint of material properties and economic efficiency, if M is yttrium (Y), then x-14~1B1M is ytterbium (Yb)! It is particularly preferable to employ =17 to 19.

The method for producing a conductive material according to the present invention involves pulverizing and mixing zirconium oxide and yttrium fluoride or ytterbium fluoride, respectively, and heating the mixture at 1100 to 1400°C in an inert gas atmosphere for 30 minutes.
0 that can be obtained by holding it for about an hour.For example, if you want to obtain (ZrO2)B5 (YF3)+5, then 0
．． 85 mol (7) ZrO2 and 0.15 mol YF3 were pulverized and mixed, and 3
It can be easily obtained by firing it for about an hour. Also ZrO2, ZrF4, Y2O3 and Yb20
:+ can be produced by firing and sintering the mixture in the same manner. However, in this case, since ZrF4 is relatively volatile, loss of ZrF4 and failure to accurately reach the target composition may occur.
There is one thing that you need to be careful about.

In addition, these solid electrolytes can be shaped using, for example, plasma spraying, vacuum evaporation, sputtering, etc. to obtain a thin film, and hot pressing, etc. to obtain a relatively thick shape.
Rubber press method.

A hot isostatic pressure sintering method or the like can be appropriately employed.

The thickness of the solid electrolyte used in the present invention is generally 1p to 5p.
■The level is appropriate. If the thickness is less than the above range, gas leakage is likely to occur due to non-uniformity, while if it exceeds the above range, resistance loss may become significantly large, which is not preferable.

In addition, the material for the anode used in the present invention includes, for example, a metal material such as platinum, silver, and cobalt, and a perovskite material such as La(:OV3), and the material for the cathode includes, for example, a metal material such as platinum, silver, and nickel. A perovskite skeleton material such as LaCoO3 can be appropriately employed.

In addition, it is necessary for gas to permeate through both of these anodes and cathodes, and for this reason, it is appropriate that these electrodes have physical properties that are porous, difficult to semi-melt, and have good adhesion to the solid electrolyte. It is. The thickness of these electrodes is generally about several thousand to about 100 μl.

These electrodes can be provided on the solid electrolyte by means such as screen printing or sputtering.

Next, the present invention will be explained by examples.

Example 1 Powders of 1 mole of ZrO20.8f and 0.14 mole of YF were pulverized and mixed using a ball mill, and then molded into pellets with a diameter of 20 os and a thickness of 2 mm using a rubber press method. This was fired at 1200''C in an argon atmosphere for 3 hours. The X-ray diffraction pattern of this sintered body was as shown in Figure 1, and the composition was (ZrO2) 86 (YF3) 0.14. After baking PT powder into the tube, we attached a PT lead wire to the surface and attached it to a sintered alumina tube using alumina cement to create an oxygen pump.This was inserted into an electric furnace with a quartz core tube.
Heating and holding at 600°C, a mixed gas of 2% oxygen and 88% argon was supplied to the inside at a flow rate of 10hu/min, and argon gas containing 20PPffi of oxygen was supplied to the outside at 100+
It was supplied at a flow rate of JL/min. After one hour, a voltage of 2V was applied between the terminals with the inner electrode as the anode and the outer electrode as the cathode, and as a result, oxygen was generated on the anode side at a rate of 0.18 cc/min.

Example 2 70.82 moles of ZrO and 0.18 moles of YbF
'a i= was mixed, molded, and fired in the same manner as Uryu side 1. The X-ray diffraction pattern of the sintered body is as shown in FIG. 2, and the composition is (ZrCl2). , 8□(YbF, ). , 18
Met.

After making an oxygen pump using this, under the same conditions as in Example 1, argon gas containing 2% oxygen was added to the 7-made side.
As a result of supplying argon gas containing 20 ppm of oxygen to the cathode side and applying a voltage of 2 V between the terminals, oxygen was generated on the 7-made side at a rate of 0.18 cc/min.

[Brief explanation of the drawing]

Figure 1.2 is an X-ray diffraction diagram of the composition used in the present invention shown in the Examples. Procedural amendment date and time) 1980 ¥-February λV Director-General of the Patent Office Mr. Kazuo Wakasugi 1, Indication of the case 1987 #Grant Application No. 180426 2, Name of the invention Butyric Concentration Pump 3, Person making the amendment Relationship to the case Patent applicant address: 132 Marunouchi 2-chome, Chiyoda-ku, Tokyo Name (
004) Asahi Glass Co., Ltd. 4, Agent 105 Address No. 2 Toranomon Chiyoda Building, 16-chome, Toranomon, Minato-ku, Tokyo January 31, 1981 (JA Date) 6. Number of inventions increased by amendment None 7 , Subject of amendment: Specification 8, Contents of amendment: Reprint of the specification (no change in content) and above

Claims (1)

[Claims] 1. General formula (Zr02) 100-! (MF3)!
(However, M=Y and x=113~25. Or M=Y
There's b-te! = 18 to 25, x is mol %) An oxygen concentrator pump using an oxygen ion conductive solid electrolyte.