JP2003137641A - Porcelain composition, composite material, oxygen separator and chemical reactor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a porcelain composition excellent in oxygen permeability in an industrial process for selectively passing and separating oxygen and a process for partially oxidizing hydrocarbon with an oxide ion mixed conductor to provide a composite material comprising a dense continuous layer of a mixed conductor utilizing the porcelain composition and a porous support and to provide an oxygen separator and a chemical reactor. SOLUTION: The porcelain composition is an oxide ion mixed conductor porcelain composition substantially having a perovskite crystal structure, the oxide ion mixed conductor porcelain composition contains at least 1) Ba, 2) Co and/or Fe and 3) In and/or Sn and/or Y, and the component 3) has been disposed at the B site of the perovskite structure.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an oxide-ion mixed conductor porcelain composition, a composite material, and oxygen, which are applied to an industrial selective permeation / separation process of oxygen, a diaphragm reactor for partial oxidation of hydrocarbons, and the like. The present invention relates to a separation device and a chemical reaction device.

[0002]

2. Description of the Related Art In recent years, a process for thinning an ion conductive material and industrially separating or purifying a specific component using the thin film has been remarkably advanced and developed. Above all, the process of selectively permeating oxygen from a mixed gas such as the atmosphere using an oxide ion conductive material to separate and purify is performed from a small-scale oxygen pump for medical use to a large-scale gas generation / purification plant. It is expected to be applied to. In addition, recently, a method of separating oxygen-mixed gas and hydrocarbon gas by a diaphragm made of an oxide ion conductive material and selectively permeating oxygen to partially oxidize hydrocarbons, that is, use as a so-called diaphragm reactor has been studied. There is.

As oxide-ion-conductive ceramic materials that can be used for this purpose, oxide-ion conductors that transmit only oxygen ions and oxide-ion mixed conductors that simultaneously transmit oxygen ions and electrons or holes are known. ing.
Among them, the oxide-ion mixed conductor can perform charge compensation for sustaining the movement of oxygen ions without forming an external current circuit because the material itself can transmit electrons or holes. Therefore, it is considered to be more suitable for oxygen separation applications. That is, in order to perform oxygen separation by the oxide-ion mixed conductor, it suffices that the oxygen potentials on both sides of this mixed conductor are made different, and only oxygen is increased from the side having a higher oxygen partial pressure to the side having a lower oxygen partial pressure. Gas components that pass through the mixed conductor cannot pass through the mixed conductor, and other gas components can selectively permeate and separate oxygen.

In order to put such oxygen selective permeation / separation process or a diaphragm reactor into practical use, a material having high oxide ion conductivity is required. As a material satisfying the requirement, a perovskite type material is required. Structured oxide-ion mixed conductors have been investigated. The perovskite structure has a site (A site) where 12 oxygen atoms of the anion coordinate and a site (B site) where 6 oxygen atoms coordinate.
Each has a crystal structure occupied by cations,
Many of the materials considered for the above purposes have C at the B site.
Contains o or Fe.

For example, [La _x Sr _(1-x) ] CoO _3- α (x is 0.1 to 0.9, α is 0 to 0. 0, which is disclosed in JP-A-56-92103.
Range of 5), or JP 61-21717 Patent disclosed in Japanese _{[La (1-x) Sr} x] [Co (1-y) Fe y] O 3- δ (x is 0.1 to 1.
0, y is in the range of 0.05 to 1.0, and δ is in the range of 0.5 to 0), etc., and porcelain compositions are known as strong candidate materials. In JP-A 6-206706 discloses In _{addition, A x Ba x 'B y} B' y 'B "y" O 3-z
(A is 1, according to the Periodic Table of Elements adopted by ICUPA,
Selected from the group consisting of groups 2 and 3 and lanthanide group of f period, B, B ′ and B ″ are selected from transition metals of d period, and 0 ≦ x ≦ 1, 0 <x ′ ≦ 1, 0 < y≤1, 0≤y'≤1, 0≤
An oxide with an extremely wide composition range in which y "≤1, x + x '= 1, y + y' + y" = 1 and z is a numerical value given when the charge of the composition is neutral) Ion transport permeable membranes have been proposed, and specific examples thereof include La _0.2 Ba _0.8 Co _0.8 Fe _0.2 O _2.6 .

As described above, many perovskite-type oxide ion mixed conductor materials contain La and Y at the A site and F at the B site in addition to the alkaline earth elements such as Ca, Sr, and Ba.
Contains additional elements such as e, Cr, and Ti. This is SrCoO
_This is because the perovskite structure becomes relatively unstable in a material containing no additional element such as _3- α, and instead, a BaNiO ₃ type hexagonal phase having an extremely low oxygen permeation rate appears.

On the other hand, H. Kusaba et al., Electrochemistry, vo
l.68, No.6 (2000) pp.409-411, Sr _0.9 Ca _0.1 Co
The crystal structure of _0.9 In _0.1 O _3- δ at room temperature is BaNiO ₃ type hexagonal crystal, and it is reported that it transforms to cubic perovskite at high temperature of 860 ℃ or higher. In addition we use SrCo _0.9 In _0.1 O
As a result of investigating the crystal structure of _3- δ, it was confirmed that it is also BaNiO ₃ type and In is an element which does not show the stabilizing effect of cubic perovskite in the composition having a high concentration of Sr at the A site.

By the way, Y. Teraoka et al. Chemistry Let
ters, Pp.503-506, in 1988, the composition formula La _0.6 A _'0.4 Co
The oxygen permeation rate of the perovskite type oxide represented by _0.8 Fe _0.2 O _{3 −} δ was investigated, and B was added to the A site of the perovskite type structure.
It is pointed out that inclusion of a can improve the oxygen transmission rate. If we extend this finding, by substituting Ba as much as possible for Sr and La, which are often used as elements that occupy the A site of perovskite-type oxides of mixed conductors, the perovskite-type mixed conductor oxides It is expected that the oxygen transmission rate can be improved. Replacing La, which is a trivalent ion, with divalent Ba, in particular, leads to an increase in oxygen vacancies in the crystal that is a carrier for oxygen transmission, and the effect of two birds with one stone is expected as a measure for improving the oxygen transmission rate. It

[0009]

[Problems to be Solved by the Invention] However, "Perovskite-related compounds" edited by The Chemical Society of Japan, Quarterly Chemistry Review, N
As shown in o.32 (1997), pp.11-13, when the A site of perovskite is replaced with Sr having a small ionic radius by Ba having a large ionic radius, a structure such as BaNiO ₃ type is formed. It is known that it is more stable and easier to appear than the perovskite structure. Even when we actually conducted preliminary experiments, while the crystal structure of the sintered body of SrCo _0.8 Fe _0.2 O ₃ -δ was cubic perovskite type, BaCo _0.8 Fe
_0.2 O _3- δ has a different crystal structure from the perovskite type,
A phase of low oxygen transmission rate was apparent. This outrage is AJ J
acobson et al. J. Solid State Chemistry, vol.35 (198
0) It was assigned to the hexagonal 12H-BaCoO _3-x type structure with a structure similar to that of BaNiO ₃ type reported in pp.334-340.

Similarly, the La _0.2 Sr _0.8 CoO ₃ -δ sintered body has a cubic perovskite type, whereas La _0.2 Ba _0.8
In CoO _3- δ, it became 12H-BaCoO _3-x type. Further, as disclosed in Japanese Patent Laid-Open No. 6-56428 by Mazanek et al., Y has been conventionally recognized as an element substituting La for substituting the A site of perovskite. A stable perovskite structure was not obtained as a result of synthesizing and investigating a composition containing B in the A site and having a large proportion of Ba, for example, Ba _0.8 Sr _0.1 Y _0.1 CoO ₃ -δ. Also HW
Brinkman et al. Soild State Ionics, vol.68 (1994) pp.1
73-176, BaCo _0.95 Y _0.05 O with Y substituted at the B site
We investigated _3- δ and reported that the crystal structure was also BaCoO _3-x type hexagonal crystal. As mentioned above, Ba of A site
It was reconfirmed that the substitution by is a factor that destabilizes the perovskite structure.

As mentioned above, BaNiO₃Different types or similar structures
Oxygen permeation rate is extremely low in the phase
Cannot be used in oxygen separators. That is, [La
_(1-x)Sr _x] [Co_(1-y)Fe_y] O_3-Conventional oxide io such as δ
In a mixed conductor material system, La and Sr at the A site are replaced by Ba
By increasing the proportion of Ba to improve the oxygen transmission rate
The cubic perovskite structure is stable.
Is insufficient, BaNiO₃It ’s like a mold
On the contrary, diren that oxygen transmission rate decreases
Had a ma.

Therefore, an object of the present invention is to provide a perovskite-type oxide-ion mixed conductor in which the proportion of Ba at the A site is high, the cubic perovskite-type phase is sufficiently stable, and a porcelain composition exhibiting a high oxygen permeation rate is obtained. To provide things. Further, by applying this, a composite material for gas separation having a high oxygen permeation rate, an oxygen separation device and a chemical reaction device are supplied.

[0013]

As a result of intensive studies, the present inventor has come up with various aspects of the invention described below.

(1) An oxide-ion mixed conductor porcelain composition having a substantially perovskite type crystal structure, wherein the oxide-ion mixed conductor porcelain composition is at least 1) Ba, 2) Co, and / or Or Fe, 3) In, and / or S
A porcelain composition characterized in that it includes n and / or Y) 1) to 3) at the same time and 3) is arranged at the B site of the perovskite structure.

(2) The porcelain composition according to (1) above, wherein the composition of the oxide-ion mixed conductor porcelain composition is represented by the following composition formula (formula 1). _{(Ba x A 1-x)} α (B 1-yz-z'-z "C y D z E z 'F z") O (3- δ) ··· ( Equation 1) where, A is Sr, Any of Ca and lanthanoid elements, or a combination comprising two or more of these elements, B is C
a combination comprising o and / or Fe, C is any of In, Y and Sn, and a combination of two or more of these, D is N
b, Ta, Ti, Zr, or a combination of two or more of them, E is Cu, Ni, Zn, Li, Mg, or a combination of two or more of these, and F is Any one of Cr, Ga, and Al, or a combination of two or more thereof, and the range of x is 0.4 ≦ x ≦ 1.0 when C is In, and 0.5 ≦ x ≦ when C is Y. Range of 1.0, 0.2 ≦ x ≦ 1.0 when C is Sn
Range, when C is a combination of two or more of In, Y, and Sn, the range of 0.2 ≦ x ≦ 1.0, and the range of y is 0.06 when C is Y.
≦ y ≦ 0.3 range, C is In, Sn, or In, Y,
In the case of a combination of two or more kinds of Sn, the range is 0.02 ≦ y ≦ 0.3, 0 ≦ z ≦ 0.2, 0 ≦ z ′ ≦ 0.2, 0 ≦ z ″ ≦ 0.2, 0.9 ≦ α ≦ 1.
1 and δ are values determined to satisfy the charge neutral condition.

(3) In the composition formula (formula 1) of the oxide-ion mixed conductor porcelain composition, both z'and z "are zero, and the porcelain composition according to (2) above. .

(4) In the composition formula (Formula 1) of the oxide-ion mixed conductor porcelain composition, all of z, z ′ and z ″ are zero, and the above (2) is described. Porcelain composition.

(5) A composite material comprising a porous support part and a membrane part including a dense continuous layer formed on the porous support part, wherein the porous support part has pores. Rate is
20% or more and 80% or less of oxide-ion mixed conductive porous oxide, and the dense continuous layer has a thickness of 10 μm or more and 1 mm.
The following oxide-ion mixed conductive oxides, wherein the porous support part, the dense continuous layer, or both the porous support part and the dense continuous layer (1) to
A composite material containing the porcelain composition according to any one of (4).

(6) Any one of (1) to (4) above
And a composite material according to (5) above.

(7) Any one of (1) to (4) above
7. A chemical reaction device comprising the porcelain composition described in 5 above, and / or the composite material described in 5) above.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION The present inventor
In the perovskite-type oxide-ion mixed conductor containing e, we searched for a material system that keeps the perovskite-type structure stable even when the proportion of Ba at the A site is increased.

As a result, as described above, it was confirmed that the more the Ba content, the more unstable the perovskite structure was, and in the composition range where the Sr concentration was high, the solid solution was performed without substitution so as to stabilize the perovskite. It has been found that even an element for which an effect can be obtained may cause a problem in which the substitution solid solution cannot be carried out in the composition range where the concentration of Ba is high, and precipitation occurs, or the perovskite stabilizing effect cannot be obtained. Therefore, the search area was expanded to a composition range containing elements that have not been studied so far as a perovskite-type oxide-ion mixed conductor material, or were not effective in a composition range where the Sr concentration is high, and earnest studies were conducted. As a result, B
In, Y, or Sn on the site, or 2 of these
It has been found that when more than one species is contained, the stabilizing effect of perovskite cannot be obtained in the composition range where the Sr concentration is high, but the stabilizing effect of the perovskite is specifically obtained in the composition range where the Ba concentration is high.

In the case of containing In, the composition having a high concentration of Ba, for example, the crystal structure of Ba _0.9 Sr _0.1 Co _0.9 In _0.1 O ₃ -δ is a cubic perovskite type within the temperature range of room temperature to 1000 ° C., Moreover, it was found that the oxygen permeation rate was also extremely high. On the other hand, In and Al, which belong to the same genus as the periodic table, do not have such a strong stabilizing effect on the perovskite structure in the composition range in which the proportion of Ba is high.

On the other hand, the case containing Y are, Ba _0.9 Sr _{0 .1} Co Ya _0.9 Y _0.1 O _{3- δ} is a composition which was placed in the B site
Regarding the crystal structure of BaCo _0.9 Y _0.1 O _3- δ, it was found that the cubic perovskite type is stable in the temperature range from room temperature to over 1000 ℃. A more detailed examination of these perovskite type oxides revealed that the lattice constant was even larger than that of other perovskite oxides containing Ba to the same extent, for example, Ba _0.9 Sr _0.1 Co _0.9 In _0.1 O _{3 −} δ. I confirmed the thing. This result shows that Y has a strong perovskite stabilizing effect in Ba _0.9 Sr _0.1 Co _0.9 Y _0.1 O ₃ -δ, etc. Rather than Co, which has a smaller ionic radius than Y
It means that it is because it is in B site by replacing. It was also found that in order to obtain this perovskite stabilizing effect by Y alone, it is necessary to replace Y by 6% or more.

On the other hand, for example, in SrCo _0.9 Y _0.1 O ₃ -δ, a heterogeneous phase is formed, and in a composition containing a large proportion of Sr, Y
Even if B was placed at the B site, the perovskite stabilization effect was insufficient. In addition, the crystal structure of lanthanoid elements, such as Ba _0.9 Sr _0.1 Co _0.9 La _0.1 O _3- δ, in which La or the like is often present similar to Y, at the B site, was not perovskite type. From the above results, it was concluded that Y dissolved in the B site is a perovskite stabilizing element that acts specifically in the composition range in which the proportion of Ba is high.

Further, as a result of further search, in the composition range in which the proportion of Ba is high, the one containing Sn at the B site is also
It was found that the perovskite structure is specifically stabilized.

Based on the above new findings, the composition range in which the perovskite stabilizing effect can be obtained for each element was obtained, and further, the coexistence with other elements was intensively studied to complete the present invention.

As is clear from the above, the point of the present invention is that in the oxide-ion mixed conductor having a perovskite type structure containing Ba and Co and / or Fe, I is present at the B site.
By containing any one of n, Sn and Y, or two or more of them, the perovskite structure can be stably present even in the high Ba content composition range. Of these, especially
It is important for Y to be placed at the B site in order to obtain the effects of the present invention.

A more specific composition of the porcelain composition provided by the present invention is represented by the following composition formula (Ba _x A _1-x ) α (B _{1-yz-z'-z "} C _y D _z E _{z '} F _{z "} ) O _(3- δ ₎ ... (Equation 1)

The porcelain composition provided by the present invention has a perovskite type crystal structure. The A site of this perovskite type structure is not only Ba but also one or more kinds selected from Sr, Ca and lanthanoid elements. The element may be included. These elements are represented by A in (Equation 1). Thus, the coexistence of elements other than Ba further improves the stability of the perovskite structure. However, as is clear from the above description, in order to obtain a mixed conductor material having a higher oxygen transmission rate, it is better that the proportion of Ba is higher. Ba which is preferable for keeping the perovskite structure stable
The ratio of C depends on whether the C element in (Equation 1) is In, Y, or Sn. The ratio of Ba at the A site is represented by x in (Equation 1), and when C is In, 0.4 ≦ x ≦ 1.0, more preferably 0.6 ≦ x ≦ 1.0, and when Y, 0.
5 ≦ x ≦ 1.0, more preferably 0.6 ≦ x ≦ 1.0,
In the case of Sn, 0.2 ≦ x ≦ 1.0, more preferably 0.5 ≦ x ≦ 1.0
And in the case of a combination of two or more of In, Y and Sn, 0.2 ≦ x ≦ 1.0, more preferably 0.6 ≦ x ≦
It is in the range of 1.0. If x is small outside these ranges, that is, if the proportion of Ba is small, the stabilization of the perovskite structure is insufficient and a hetero phase such as BaNiO ₃ type is generated.

B and B sites of the perovskite structure are Co and Fe.
At least one of In, Y, and Sn must be included. As described above, In, Y and Sn may be used alone or in combination. The ratio of In, Y, and Sn at the B site is represented by y in (Equation 1), but when C is Y alone, it is 0.0.
6 ≦ y ≦ 0.3, either In or Sn, or I
0.02 ≦ y ≦ 0 in the case of a combination of two or more of n, Y and Sn.
3, more preferably 0.05 ≦ y ≦ 0.2. In, Y,
When the amount of Sn is increased, the stability of the perovskite structure is improved, but when the amount is out of this range, the problems such as generation of the second phase and deterioration of oxygen permeation performance occur. On the other hand, if the amount is out of this range and the amount is reduced, the stabilization of the perovskite structure becomes insufficient.

The mixed conductor materials provided by the present invention include Nb, Ta, Ti, Zr, Cu, Ni, Zn, Li, Mg, Cr, Ga and Al.
May be included. Each of these elements substitutes the B site of the perovskite structure, but from the viewpoint of the oxygen permeation rate or the stability of the perovskite structure, there is a preferable substitution range for each element. In (Equation 1), D is Nb, Ta, Ti, or Zr,
Or a combination of two or more of these, E is Cu, Ni, Z
n, Li, Mg, or a combination of two or more of these, F is any of Cr, Ga, Al, or a combination of two or more of these, and 0 ≦ z ≦ 0.2, 0 ≦ z '≦ 0.
2, 0 ≦ z ″ ≦ 0.2 is preferable. If the amount of element substitution is increased outside these ranges, a different phase may be formed,
Problems such as a significant decrease in oxygen transmission rate occur. In addition to this, in order to obtain a higher oxygen transmission rate, Co
It is preferable that 1-yz-z'-z "≧ 0.7, which indicates the content of Fe or Fe.

The ratio α between A site and B site is 0.9 ≦ α ≦ 1.
1, more preferably within the range of 0.98 ≦ α ≦ 1.02, and by shifting this ratio from 1, the sinterability of the material can be controlled to some extent. However, if the ratio of A site and B site is out of this range, the second phase is generated, which is not preferable. In particular, when Y is included, when the value of α becomes smaller than 0.9, the tendency to form a different phase becomes strong.

The oxide-ion mixed conductor does not show significant deterioration in characteristics even if it contains some impurities. However, the permissible amount is 5% or less, preferably 2% or less of the total molar ratio of elements. If impurities are contained outside this range, problems such as generation of a different phase and reduction of oxygen permeation rate occur. On the other hand, the oxide-ion mixed conductor of the present invention can be compounded with the second phase to the extent that it does not affect the oxygen permeability. For example, by compounding with a metal such as Ag, Ag-Pd, or Pt in an amount of about 2 to 20% by mass, sinterability and material strength can be improved.

The porcelain composition provided by the present invention is a catalyst for promoting oxygen exchange reaction on a porous support, a dense continuous layer, or a membrane surface in a composite material for oxygen separation or for a chemical reaction device. Can also be used as
When this material is used as the porous support, it is relatively easy to match the thermal expansion with the metal member constituting the device, and the gas phase and the oxide ion mixed conductor on the surface of the dense continuous layer The effect of promoting the oxygen exchange reaction between the two is also obtained. On the other hand, when this material is used as a dense continuous layer, a composite material having a particularly high oxygen transmission rate can be manufactured.

In the composite material provided by the present invention, the porosity of the porous support should be in the range of 20% to 80%. When the porosity is out of this range, there arises a problem that the ventilation resistance becomes large in oxygen permeation or the mechanical properties of the support are largely impaired.
The preferred range of the thickness of the porous support varies depending on the configuration of the device and the operating conditions, but is typically 500 μm or more and 10 mm or less. When the thickness of the porous support is out of this range, there is a problem that ventilation resistance increases in oxygen permeation. When the thickness is out of this range, the mechanical properties of the support become insufficient. On the other hand, the dense continuous layer preferably has a thickness of 10 μm or more and 1 mm or less. If the thickness of the continuous phase deviates from this range, the amount of leak gas increases or the oxygen permeation rate decreases.

For the production of the porous support according to the present invention, a method usually used for producing a ceramic porous body can be used. As one of the methods, there is a method of firing an oxide containing a necessary element as a raw material. As the raw material, in addition to oxides, salts, for example, inorganic acid salts such as carbonates, nitrates and sulfates, organic acid salts such as acetates and oxalates, halides such as chlorides, bromides and iodides, or There is a method in which a hydroxide and an oxyhalide are used, and these are mixed at a predetermined ratio and fired. Further, among the above-mentioned salts, a water-soluble one is dissolved in water at a predetermined ratio and evaporated to dry, or a method in which it is dried by a freeze-drying method or a spray-drying method and then baked, a water-soluble After dissolving the salts in water, an alkaline solution such as ammonia water is added, and a coprecipitation method in which a hydroxide is precipitated to be fired, or a metal alkoxide is used as a raw material, and a gel is obtained by hydrolyzing this. A sol-gel method of firing is also applicable.

Firing of the porous support is generally carried out in two stages of calcination and main firing (sintering). Calcination is 400
In the temperature range of ~ 1000 ℃, do it for several hours to more than 10 hours,
It is usual to produce a calcined powder. This calcined powder may be molded as it is for main firing, or a resin such as polyvinyl alcohol (PVA) may be mixed with the calcined powder for shaping and main firing. The temperature of the main calcination varies depending on the composition and the like, but is usually 700 to 1400 ° C, preferably 1000 to 1350 ° C. The time for the main calcination depends on the composition and the calcination temperature, but it usually takes several hours or longer. The atmosphere for the main calcination is generally sufficient in the air, but the calcination may be carried out under a controlled atmosphere if necessary. As a means for molding the porous support, the calcined powder or mixed powder may be packed in a die and pressed and molded in the same manner as in the production of ordinary bulk ceramics, or it may be a slurry casting method or extrusion molding. You may use the method etc.

On the other hand, the dense continuous film can be produced by a method usually used for producing a ceramic film.
The film may be formed by a so-called thin film forming method such as PVD or CVD such as vacuum deposition method, but it is simpler and more economical to apply slurry-like raw material powder or calcined powder on the porous support. The firing method is preferred.

The firing temperature of the dense continuous film must be selected such that the film is densified so that gas leakage does not occur and the porosity of the porous support is not significantly reduced during this firing process. . Normal firing temperature is 700-1400
C., preferably in the range of 1000 to 1350.degree. The firing time usually takes several hours. The firing of the dense continuous film may be performed separately after the main firing of the porous support, or may be performed simultaneously with the main firing of the support. The density of the dense continuous film is preferably set so that gas leakage does not occur.
It is 85% or more, and more preferably 93% or more.

In order to selectively permeate and separate oxygen from a mixed gas containing oxygen by the composite material formed by the above process, the oxygen potentials on both surfaces of the composite material may be made different. For example, in order to separate oxygen from the atmosphere, the raw material atmosphere side may be pressurized or the oxygen extraction side may be depressurized. For example, the raw material atmosphere side is 10-30
Oxygen can be produced by pressurizing to atmospheric pressure and setting the permeated oxygen side to 1 atm. In addition, the atmospheric pressure of the raw material is 1 atm to 30 atm,
The permeated oxygen side may be depressurized to about 0.05 atm by a pump.
Moreover, in order to produce oxygen-enriched air,
The pressure may be increased to 30 atm and the atmospheric pressure of 1 atm may be supplied to the opposite side. The operating temperature for this oxygen separation is in the range of 500 to 1000 ° C, preferably 650 to 950 ° C.

As described above, the composite material and the porcelain composition of the present invention can be applied to a device for producing pure oxygen or oxygen-enriched air. Furthermore, it can be used for applications other than oxygen separation, especially for a chemical reaction device involving an oxidation reaction. For example, it can be used for a reactor for a partial oxidation reaction of methane, which produces a synthesis gas composed of carbon monoxide and hydrogen from methane.
Conventionally, a reaction apparatus has been used in which a mixed gas of methane and oxygen is used as a starting material to obtain a synthesis gas by a catalytic reaction.

On the other hand, in the reactor using the mixed oxide-ion conductive ceramics of the present invention, for example, air (or a mixed gas containing oxygen) and methane are separated and separated by the mixed oxide-ion conductor to flow separately. , The surface of the mixed oxide-ion conductor on the side where methane is flowing is coated and placed with a catalyst for producing synthesis gas such as Rh. Ceramics 500-100
By heating to a temperature range of about 0 ° C., only oxygen permeates according to the same principle as oxygen separation, and then reacts with methane on the methane side ceramic surface to generate synthesis gas.

Therefore, in the method according to the present invention, unlike the conventional method, it is not necessary to produce oxygen in advance, the raw material gas is not mixed, and the synthesis gas can be efficiently obtained. It is possible to obtain a great effect such as. Further, in addition to partial oxidation of methane, it can be used for any chemical reaction device involving an oxidation reaction, such as partial oxidation of hydrocarbons for forming olefins, partial oxidation of ethane, and substitution of aromatic compounds.

[0045]

EXAMPLES Examples of the present invention will be described below, but these are for the purpose of illustration only, and the scope of the present invention is not limited to these contents.

In this example, a dense sintered body sample was prepared, and the crystal structure and oxygen permeation rate were evaluated. The raw materials of the sample are CaCO ₃ , SrCO ₃ , BaCO ₃ , La ₂ O ₃ , Fe ₂ O ₃ , Co ₃ O ₄ , I
n ₂ O ₃ , Y ₂ O ₃ , SnO ₂ , Nb ₂ O ₅ , Ta ₂ O ₅ , TiO ₂ , ZrO ₂ , CuO, Ni
O, ZnO, Li ₂ CO ₃ , MgO, Cr ₂ O ₃ , Ga ₂ O ₃ , Al ₂ O ₃ were weighed in the required amounts, and then isopropyl alcohol was used as the dispersion medium and zirconia balls were mixed for 24 hours with a ball mill. I went. The obtained slurry is dried, crushed, and Mg
It was packed in a square pod made of O and calcined in the air at 850 ° C for 12 hours. The obtained calcined powder was crushed, packed into a 12 mmφ die, uniaxially molded into a tablet, further packed into an ice bag, and CIP molded. 1000 ° C in the MgO square sheath.
Approximately 10m after firing for 5 hours at a sintering temperature in the range of ~ 1300 ℃
A sintered body of mφ was obtained.

This sintered body was ground to a thickness of 1 mm, adhered to the tip of an Al ₂ O ₃ tube, exposed to the air on the outside and depressurized on the inside. The oxygen partial pressure on the reduced pressure side was measured, and the oxygen permeation rate was obtained based on the difference from the partial pressure value when oxygen did not permeate through the sintered body. The sample temperature was 850 ° C. The oxygen permeation rate is represented by the volume of permeated oxygen per unit surface area of the mixed oxide ion conductor per minute in a standard state, and the unit is ml / cm ² · min. The presence or absence of gas leak when passing through the sintered body sample was examined using a helium leak detector with the outside gas changed to a mixed gas of air and helium. As a result, no gas leak was observed in the samples within the scope of the present invention.

Table 1 shows the composition of the sintered body sample, the identification result of the constituent phase by the powder X-ray diffraction method at room temperature, and the measured value of the oxygen permeation rate.

[0049]

[Table 1]

[0050] Here, the composition of the samples, the following composition formula _{(Ba x A 1-x)} α (B 1-yz-z'-z "C y D z E z 'F z") O (3- δ ₎ ... (Equation 1) and expressed by constituent elements and composition ratios. In the column of constituent phase, ○
Was a cubic perovskite phase single phase, x is Ba
It indicates that it contained a hetero phase such as NiO ₃ type hexagonal crystal. From this table, it can be confirmed that the materials within the scope of the present invention have a cubic perovskite structure that is stable even at room temperature and have a high oxygen permeation rate.

[0051]

According to the present invention, in a perovskite-type oxide-ion mixed conductor, the proportion of Ba at the A site is high, the cubic perovskite-type phase is sufficiently stable, and a porcelain exhibiting a high oxygen transmission rate is obtained. The composition can be realized. Furthermore, it is possible to apply this porcelain composition to the technical fields such as selective permeation / separation process of oxygen by oxide-ion mixed conductor, or diaphragm reactor for partial oxidation of hydrocarbon, and to exert excellent oxygen permeation characteristics. Is. This porcelain composition can be used as a dense continuous layer of a composite material used in an oxygen separator or the like, or as a porous support,
It is also suitable as a catalyst. These technologies provided by the present invention greatly contribute to higher performance and lower cost of an oxygen separation device from air or a diaphragm reactor.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C01G 51/00 C01B 3/38 4G075 // C01B 3/38 C04B 35/00 H (72) Inventor Wataru Ito 20-1 Shintomi, Futtsu City Inside the Technology Development Headquarters, Nippon Steel Corporation (72) Inventor Tadashi Saki 20-1 Shintomi, Futtsu City Inside the Technology Development Headquarters, Nippon Steel Co., Ltd. F-term (reference) 4D006 GA41 KA12 MA24 MA31 MB07 MC03 NA31 NA46 PA04 PB17 PB62 PC69 PC71 4G030 AA02 AA07 AA08 AA09 AA10 AA11 AA12 AA16 AA17 AA20 AA21 AA22 AA27 AA28 AA29 AA31 AA32 AA34 AA36 AA39 BA32 CA01 CA08 4G040 EA03 EA07 EB01 4G042 BA30 BA35 BB02 BC05 4G048 AA05 AC08 AD02 AD08 4G075 AA05 BA01 BD14 CA54 EC30 FB04 FC02

Claims (9)

[Claims] 1. A porcelain composition of an oxide-ion mixed conductor having a substantially perovskite crystal structure, which comprises at least (1) Ba, (2) Co, and / or Fe,
(3) In and / or Sn, and / or Y (1) to
A porcelain composition comprising the element (3) at the same time, and the element (3) being arranged at the B site of the perovskite structure. 2. The porcelain composition according to claim 1, which has a composition represented by the following composition formula (Formula 1). _{(Ba x A 1-x)} α (B 1-yz-z'-z "C y D z E z 'F z") O (3- δ) ··· ( Equation 1) where, A is Sr, Any one of Ca and lanthanoid elements,
Or a combination containing two or more of these, B is a combination containing Co and / or Fe, C is any one of In, Y and Sn, and a combination of two or more thereof. D is Nb, Ta, Ti, or Zr, or 2 of these
Combination of two or more kinds, E is any one of Cu, Ni, Zn, Li, Mg, or a combination of two or more of these, F is any one of Cr, Ga, Al, or two or more of these , The range of x is 0.4 ≦ x ≦ 1.0 when C is In, and C is Y
In the range 0.5 ≤ x ≤ 1.0, and when C is Sn 0.2 ≤ x
≦ 1.0 range, 0.2 ≦ x ≦ 1.0 when C is a combination of two or more of In, Y and Sn, y range is 0.06 ≦ y ≦ 0.3 when C is Y Range, C is In,
In the case of any one of Sn or a combination of two or more of In, Y and Sn, the range is 0.02 ≦ y ≦ 0.3, 0 ≦ z ≦ 0.2, 0 ≦ z ′ ≦ 0.2, 0 ≦ z ″ ≦ 0.2, 0.9 ≦ α ≦ 1.1 and δ are values determined so as to satisfy the charge neutral condition. 3. The porcelain composition according to claim 2, wherein both z ′ and z ″ in the composition formula (formula 1) are 0. 4. The porcelain composition according to claim 2, wherein in the composition formula (Formula 1), all of z 1, z ′ and z ″ are 0. 5. A composite material comprising a porous support part and a membrane part including a dense continuous layer formed on the porous support part, wherein the porous support part has a porosity. Has a mixed oxide-ion conductive porous oxide of 20% or more and 80% or less, and the dense continuous layer is a mixed oxide-ion conductive oxide having a thickness of 10 μm or more and 1 mm or less, 5. A porous support part, or the dense continuous layer, or both the porous support part and the dense continuous layer, containing the porcelain composition according to any one of claims 1 to 4. Composite material to do. 6. An oxygen separation device for selectively permeating and separating oxygen from a mixed gas containing oxygen, wherein the porcelain composition according to any one of claims 1 to 4 or claim 5. An oxygen separation device comprising the composite material of. 7. An oxygen separator for selectively permeating and separating oxygen from a mixed gas containing oxygen, wherein the porcelain composition according to any one of claims 1 to 4 and claim 5. An oxygen separation device comprising the composite material of. 8. A chemical reaction device for performing a chemical reaction involving an oxidation reaction, comprising the porcelain composition according to any one of claims 1 to 4 or the composite material according to claim 5. And a chemical reactor. 9. A chemical reaction device for performing a chemical reaction involving an oxidation reaction, comprising the porcelain composition according to any one of claims 1 to 4 and the composite material according to claim 5. And a chemical reactor.