CN1121257C - Ceramic material for making compact oxygen-permeable separation membrane and and its oxygen permeable membrane separator - Google Patents

Abstract

The present invention relates to a metallic oxide ceramic material which can be used for preparing compact oxygen-permeable separation films, which is characterized in that certain layers in a crystal cell structure can singly transmit oxygen ions, and other layers singly transmit electrons. The material comprises Bi2Sr2Ca<n-1>Cu<n>O<2n+4>, Bi2Sr2(R<1-x>Ce<x>)2Cu2 and Ba<2-x>M<x>Cu<4-x'>M'<x'>O<8-delta>. The material has high mixing conductivity of oxygen ions and electrons and excellent combination performance. Compact films prepared from the material have extremely high permselectivity, and can structure an efficient medium-high temperature permeable-film oxygen separator which can separate pure oxygen from mixed gas which comprises oxygen.

Description

A kind of ceramic of compact oxygen-permeable separation membrane and permeable membrane oxygen separator

The present invention relates to the ceramic of compact oxygen permeable membrane and the oxygen separator thereof of oxonium ion electronics mixed conducting.

Traditional main low-temperature fractionation technology that adopts air of oxygen preparation also has chemistry and electrochemical method for producing oxygen through in addition.But low-temperature fractionation technology system oxygen only just has scale and benefit when large-scale production (50-2000 ton/sky), and the efficient of chemistry and electro-chemistry oxygen-producing technology is lower.

United States Patent (USP) 5108465 has been reported a kind of oxygen permeable membrane system oxygen technology based on the oxonium ion electron mixed conductor, the method oxygen generation efficiency height, and do not have the scale restriction, be specially adapted to midget plant.Simultaneously, because the operating temperature of this oxygen permeable membrane system oxygen technology is middle high temperature (700-1200 a ℃), also is easy to relate to the coupling of oxygen industrial process and simplifies technology, cut down the consumption of energy with some.

The Primary Component of oxygen permeable membrane oxygenerator is the oxygen permeable membrane dividing plate, and the performance of its material therefor is directly determining the quality of oxygen separator.

The high temperature oxygen permeable membrane material that has now disclosed is broadly divided into two classes: a class is the Ca-Ti ore type composite metal oxide, and another kind of is oxonium ion solid electrolyte-metal two-phase composite.As United States Patent (USP) 5,269, the 822 compact oxygen permeable film material La that disclose _0.2Ba _0.8Co _0.8Fe _0.2O _3-zBe the perovskite structure of oxygen vacancy, its oxonium ion and electronics can be respectively by oxygen room and electron hole mechanism conduction, and oxygen room and electron hole then replace La by divalence Ba ion and introduce; The compact oxygen permeable film material that European patent EP 0399833A1 discloses then is oxonium ion solid electrolyte-noble metal two-phase composite, wherein the oxonium ion solid electrolyte is the zirconia of stabilisation, noble metal is palladium, platinum etc., and its oxonium ion conducts with metal by solid electrolyte respectively mutually with electronics.Above-mentioned two-phase composite oxygen semipermeable membrane material is owing to need to adopt noble metal, and the cost of film is higher; And with oxygen vacancy perovskite structure La _0.2Ba _0.8Co _0.8Fe _0.2O _3-zDeng material is the oxygen permeation membrane on basis, though the oxygen separative efficiency is higher, is substituting the La that Ba makes with Sr at present _1-xSr _xCo _1-yFe _yO _3-zObtained the highest oxygen separative efficiency in the oxygen separation membrane, but because its mechanical property and chemical stability also has big distance from practical application.

European patent EP 0399833A1 has disclosed material has been improved the combination property that improves material from technology, as makes anisotropic membrane or make the cermet two-phase, and satisfying the actual working environment needs, but cost is higher; The Bi that United States Patent (USP) 5273628 discloses ₂O ₃Doping oxide oxygen parting material operating temperature is low, oxygen permeability is also higher, but chemical stability is not high, and their mechanical property is not effectively solved simultaneously; And according to U.S.'s " electrochemistry magazine " (J.Electrochem.Soc., 143,1736,1996) report, a kind of new mixed ion conductor oxygen flow material SrFe _1.5-xCo _xO _zSystem has good chemical stability, but its oxygen flow efficient is not high under the little gradient.Thereby the oxygen flow parting material of seeking new excellent combination property remains the major tasks of current oxygen permeable membrane research.

To Bi ₂Sr ₂Ca _N-1Cu _nO _2n+4(n=1-3) the visible German journals of the report of system " Condensed Matter Physics B " (Z.Phys.B, Condenced Matter, 68,421 (1987)) and Japan " applicating physical magazine " (Jpn.J.Appl.Phys., 27, L209 (1988)); To Bi ₂Sr ₂(R _1-xCe _x) ₂Cu ₂O ₁₀The visible Britain of report " nature " magazine (Nature, 342 (1988), 890) of (R=rare earth element) system; To (Pb ₂Cu) Sr ₂A _N-1Cu _nO _2n+4(A=rare earth, Ca) the visible Britain of the report of system " nature " magazine (Nature, 336 (1988) 211); And RBa _2-xM _xCu _{3-x '}M ' _{X '}O _{6+ δ}(R=rare earth element, M=Sr, Ca, Mg, M '=Fe, Co, Ni, Al, Ga, Zn etc.) visible U.S. of system " physical comment bulletin " (Phys.Rev.Lett., 58 (1987) 908) and " Science Bulletin " (32,1987,412 pages).To above-mentioned various oxide material systems, existing report is only paid attention to the research of its low-temperature superconducting character, yet there are no the report of using it for the oxygen parting material.

Based on accumulation in the research work for many years of oxygen permeable membrane field, we seek in the high temperature superconducting oxide system and have found that above-mentioned all kinds of oxide material has the layer structure of special oxonium ion electrical conductivity character, can and relate to the oxygen membrane reactor used as oxygen permeability and separation material structure oxygen separator.

The purpose of this invention is to provide the metal oxide ceramic of compact oxygen permeable membrane of a class oxonium ion electronics mixed conducting rate height, excellent combination property, and construct and a kind ofly can particularly separate high temperature ceramic of compact permeable membrane oxygen separator in pure oxygen efficient the air from the mist that contains oxygen.

Metal oxide ceramic of compact oxygen-permeable separation membrane of the present invention is characterised in that and adopts the layer structure material with special oxonium ion electrical conductivity characteristic, and promptly some layer can single-minded ground conduct oxygen ions in its cell configuration, and the other layer is special-ground conduction electron then; This class material comprises: 1) Bi ₂Sr ₂Ca _N-1Cu _nO _2n+4(n=1-3) system comprises and uses Pb, and Sb partly substitutes Bi, substitutes Sr with Ba or rare earth element, substitutes Ca with rare earth element y, substitutes Cu with transition-metal Fe, Co, Ni; 2) Bi ₂Sr ₂(R _1-xCe _x) ₂Cu ₂O ₁₀(R=rare earth element; X=0-0.3) system; 3) (Pb ₂Cu) Sr ₂A _N-1Cu _nO _2n+4(A=rare earth, Ca; N=1,2) system; 4) RBa _2-xM _xCu _{3-x '}M ' _{X '}O _{6+ δ}(R=rare earth element; M=Sr, Ca, Mg; M '=Fe, Co, Ni, Al, Ga, Zn; X=0-0.5) and RBa _2-xM _xCu _{4-x '}M ' _{X '}O _8-δ(R=rare earth element; M=Sr, Ca, Mg; M '=Fe, Co, Ni, Al, Ga, Zn; X=0-0.5; δ is the non-stoichiometry of oxygen, and span is 0-1) system.

Prepare compact ceramic oxygen permeable membrane with above-mentioned metal oxide materials, can utilize the existing method that generally prepares ceramic membrane, as wet chemistry methods such as solid-state chemical reaction method, coprecipitation, sol-gels.Its program comprises powder preparation, moulding, burns till and back processing.

The metal oxide ceramic material that adopts above-mentioned technology to make can be processed into the oxygen flow isolation features film of difform densifications such as tabular, tubulose according to the needs that reality is used.For example, can adopt extrude, single shaft pressurization or casting mode prepare the tabular oxygen permeation membrane, or adopt extruding-out process to prepare tubulose or cellular oxygen permeation membrane; Can also be at the less compact ceramic oxygen permeable membrane of porous support substrates top casting one layer thickness.The ceramic body that extrusion molding or casting method obtained also needs through suitable heat treatment, gets rid of the moisture content and the organic additive that comprise, and then high temperature sintering obtains fine and close ceramic oxygen-permeable membrane.Utilize compact oxygen permeable ceramic film can constitute the permeable membrane oxygen separator.

Fig. 1 has provided the device schematic diagram of tabular permeable membrane oxygen separator.

Ceramic of compact permeable membrane oxygen separator of the present invention comprises by adding a dividing plate 3 in the middle of two air chambers 1,2 forming the spy Levy the compact ceramic oxygen permeable membrane preparation that is that described dividing plate 3 is proposed by the present invention; The material that this oxygen permeation membrane adopts comprises: 1) Bi₂Sr ₂Ca _n-1Cu _nO _2n+4(n=1-3) system comprises with Pb, Sb partly substituting Bi, with Ba or rare earth element Substitute Sr, substitute Ca with rare earth element y, substitute Cu with transition-metal Fe, Co, Ni; 2) Bi₂Sr ₂(R _1-xCe _x) ₂Cu ₂O ₁₀(R=rare earth element; X=0-0.3) system; 3) (Pb₂Cu)Sr ₂A _n-1Cu _nO _2n+4(A=rare earth, Ca; N=1,2) system; 4) RBa_2-xM _xCu _3-x′M′ _x′O _6+δ(R=rare earth element; M=Sr, Ca, Mg; M '=Fe, Co, Ni, Al, Ga, Zn; X=0-0.5) and RBa_2-xM _xCu _4-x′M′ _x′O _8-δ(R=rare earth element; M=Sr, Ca, Mg; M '=Fe, Co, Ni, Al, Ga, Zn; X=0-0.5; δ is the non-stoichiometry of oxygen, and span is 0-1) system.

Said apparatus when as oxygen separator, can be in a side air chamber 1 of barrier film through air inlet 4 introduce compressed air or Other oxygen containing mist, and 5 discharges through the gas outlet; Connecing vavuum pump in the outlet 6 of the air chamber 2 of barrier film opposite side takes out Sky exists certain partial pressure of oxygen poor to guarantee the barrier film both sides, under the driving of partial pressure of oxygen difference oxygen from the high keto sectional pressure end through densification The dividing plate of oxygen penetration material preparation infiltrate into the low oxygen partial pressure end, draw and obtain pure oxygen through vacuum pump outlet.

Said apparatus also can be used as and relates to the oxidation membrane reactor, and can introduce compressed air this moment in a side air chamber 1 of barrier film Or other oxygen containing mist, in the opposite side air chamber 2 of barrier film, introduce the reproducibility reactive material, by the high keto sectional pressure end The pure oxygen that infiltrates can be in film surface and the reaction of reproducibility reactive material under the effect of catalyst, and the generating portion oxidation product is used In the chemical reaction raw material. An important feature of its technology is can realize oxygen separator and partial oxidation reactor integrated.

Owing in the listed high-temperature oxide superconducting material crystal structure of the invention described above CuO is arranged₂Face exists, its CuO₂Face Layer has very high electronics (or hole) conductance, is the desirable passage of electronics (or hole) conduction. Wherein a class contains The oxide superconductor of the metallic element such as Bi, Pb, Bi in its structure₂O ₂Layer and PbO layer allow oxonium ion by the oxygen room Or interstitial oxygen concentration mechanism realizes diffusion. Also have a type oxide superconductor, the CuO chain layer that contains in its structure is oxonium ion The favourable passage of diffusion. To the research of oxygen penetration material, we recognize and propose in this single structure cell based on for many years Warm oxygen penetration material during the composite metal oxide that oxonium ion and electronics (or hole) conduct along different layers can be used as. Above-mentioned These materials all have the layer structure of special oxonium ion Electronic Transport of Two Benzene: 1) Bi₂Sr ₂Ca _n-1Cu _nO _2n+4(n=1-3) system: the structure cell of this system contains CuO₂Layer and Bi₂O ₂Layer can divide Other conduction electron and oxonium ion, thereby oxygen had the selection through performance. This composite metal oxide allows its institute The metal ion that contains substitutes to adjust optimizes crystal structure and rerum natura. For example, can use Pb, Sb partly to substitute Bi, with Ba or rare earth element such as the alternative Sr of La, usefulness rare earth element such as Y substitute Ca, usefulness transition metal such as Fe, The alternative Cu such as Co, Ni. 2) Bi₂Sr ₂(R _1-xCe _x) ₂Cu ₂O ₁₀(R=rare earth element) system: similar with above-mentioned system, this material system is by SrO-BiO-BiO-SrO and CuO₂-(R，Ce)-O ₂-(R，Ce)-CuO ₂Two-layer alternately stack consists of, CuO wherein₂Layer and Bi₂O ₂Can distinguish conduction electron and oxonium ion, thereby oxygen is had the selection through performance. 3) (Pb₂Cu)Sr ₂A _n-1Cu _nO _2n+4(A=rare earth, Ca) system: the PbO-CuO-PbO that this system is contained and CuO₂Layer can be distinguished conduct oxygen ions and electronics, also answers the aerobic Penetration Signature. 4) RBa_2-xM _xCu _3-x′M′ _x′O _6+δ(R=rare earth element; M=Sr, Ca, Mg; M '=Fe, Co, Ni, Al, Ga, Zn and Sn) and RBa_2-xM _xCu _4-x′M′ _x′O _8-δ(R=rare earth element; M=Sr, Ca, Mg; M '=Fe, Co, Ni, Al, Ga, Zn and Sn) system: comprise oxygen ion conduction CuO chain layer and electricity in the structure cell of these systems Son conduction CuO₂Surface layer. By appropriate mechanics and the chemistry that to optimize these compact ceramic oxygen permeable membranes that substitute Stability and oxygen separative efficiency.

Utilize the oxonium ion electronics layering transport properties of above-mentioned this class material, can on the structure cell level, regulate and control the composition and the arrangement mode of oxygen ion conduction layer and electronic conductive layer, in the oxygen permeability that improves membrane material, coordinate, optimize mechanics and chemical stability.We preferably come out them from numerous hybrid ionic electronics oxide materials, are used as oxygen permeability and separation membrane material with the structure oxygen separator, have obtained satisfied result at middle warm area.

Compare with existing oxygen penetration material, above-mentioned this class that we find has the layer structure oxide of special oxonium ion electrical conductivity character, has the following advantages:

At first, its stratiform cell configuration characteristics make us can carry out element substitution or doping in a certain channel layer, or increase and decrease the combination property that the number of plies of a certain passage is come the coordination optimization material by intercalation, can improve the mechanical property of material as doping Sn element in the YBCO system;

Its two, its stratiform product born of the same parents structure ion electronics shunting characteristics make us can carry out element substitution in a certain channel layer or mix to change the transport property of this passage, as mixing the Co element at Cu-O chain layer, have improved oxygen permeability; Or lead by the electricity that the number of plies that intercalation increases and decreases a certain passage is coordinated ion and electronics, change electronic conductance as the number of plies of increase and decrease electronic conduction layer Cu-O face;

Its three, experiment shows: Bi ₂Sr ₂Ca _N-1Cu _nO _2n-4(n=1-3) and RBa _2-xM _xCu _{3-x '}M ' _{X '}O _{6+ δ}(R=rare earth element; M=Sr, Ca, Mg; M '=Fe, Co, Ni, Al, Ga, Zn and Sn) system is good middle warm area oxygen permeability and separation material, and Bi ₂Sr ₂Ca _N-1Cu _nO _2n+4(n=2) oxygen permeability of system 800 ℃, when thickness is 1.4 millimeters, can obtains pure oxygen and reach 4.0m ³M ^-2Day ^-1

At last, more than the preparation condition gentleness of various materials, cost of material is not high, helps producing in batches.

Below in conjunction with the description of drawings embodiments of the invention.

Embodiment 1 preparation Bi ₂Sr ₂CaCu ₂O ₈Compact oxygen permeable film and structure tabular permeable membrane oxygen separator

Bi ₂Sr ₂Ca _N-1Cu _nO _2n+4The structure cell of material system contains CuO ₂Layer and Bi ₂O ₂Layer can be distinguished conduction electron and oxonium ion, thereby oxygen is had the selection through performance.

Bi ₂Sr ₂CaCu ₂O ₈The compact oxygen permeable film preparation process is as follows: by the accurate weighing reactant of needed stoicheiometry bismuth oxide, cupric oxide, strontium carbonate and calcium carbonate, fully mix and grinds, calcined 12-24 hour at 800 ℃ then.For guaranteeing that solid-state reaction carries out fully, product is even, and the sample that the calcining back obtains needs grinding again, mixing, cake of press, calcining again, can carry out repeatedly repeatedly in case of necessity, is verified as pure phase until the X-ray material phase analysis.To be pressed into flake shaped base substrate with the ceramic powder of method for preparing, and slowly be warming up to 820-870 ℃ of insulation 12-24 hour in air, cooling naturally promptly obtains Bi then ₂Sr ₂CaCu ₂O ₈Compact oxygen permeable film.

The Bi of above-mentioned acquisition ₂Sr ₂CaCu ₂O ₈The compact oxygen-permeable membrane sample at first must at room temperature check its compactness not contain the connection pore to determine it.Adopt the measurement mechanism of evaluation oxygen penetration material oxygen permeability as shown in Figure 2 to measure its oxygen permeability then.

Fig. 2 is for estimating the measurement mechanism schematic diagram of oxygen penetration material oxygen permeability;

Fig. 3 is the oxygen flow flux of several oxygen separation membrane materials and the graph of a relation of temperature.

Compact oxygen-permeable membrane sample 11 is fixed on the alumina tube 13 with glass capsulation ring 12, then logical in the upper end of film Enter the air from air bottle 7, pass into the high-purity He from helium tank 8 in the lower end of film, gas flow is respectively by two 9 controls of D07-7A/ZM type mass flowmenter (MFC). Utilize stove 10 with compact oxygen-permeable membrane sample 11 heating to be measured Arrive the melting temperature of glass capsulation ring 12 to guarantee sample 11 and alumina tube 13 good sealed knots, temperature survey is by thermocouple 14 finish. The oxygen carrier band air inlet analysis of hplc instrument (GC) of infiltration being come as high-purity He of carrier gas (or passes with oxygen Sensor) 15 measures.

The measurement mechanism reality of evaluation oxygen penetration material oxygen permeability shown in Figure 2 is a permeable membrane oxygen separator just, it has the middle characteristics that add an oxygen permeable membrane dividing plate of two air chambers, and its dividing plate is by the Bi of present embodiment preparation₂Sr ₂Ca _n-1Cu _nO _2n+4Compact oxygen permeable film material is made, and dividing plate top is the high oxygen pressure air chamber, logical atmospheric environment, and the lower partition is hypoxemia Plenum chamber, logical high-purity He carrier gas.

Experiment is found: when the end at film is introduced air, can detect a large amount of oxygen at the other end of film, and nitrogen is dense Degree is lower than detection range 5ppm, and as seen this dense film has high selection through performance to oxygen. For thickness be 1.4 the milli The Bi of rice₂Sr ₂CaCu ₂O ₈The system oxygen permeation membrane can obtain pure oxygen at 800 ℃ and reach 4.0m³·m ^-2·day ^-1, i.e. 5.5kgm^-2 day ^-1 Curve with "+" number expression among Fig. 3 has reflected Bi₂Sr ₂CaCu ₂O ₈The oxygen infiltration rate of system compact oxygen permeable film Variation relation with temperature. As seen from the figure, this dense ceramic membrane still has considerable oxygen permeability in the time of 700 ℃. By The thickness that reduces the oxygen pellicle can further improve the permeability and separation efficient of oxygen.

To n=1,3 o'clock Bi₂Sr ₂Ca _n-1Cu _nO _2n+4System has also obtained the Bi with said n=2 o'clock₂Sr ₂CaCu ₂O ₈The oxygen permeability that material is suitable.

Bi ₂Sr ₂(R _1-xCe _x) ₂Cu ₂O ₁₀(R=rare earth element) and above-mentioned Bi₂Sr ₂Ca _n-1Cu _nO _2n+4System is similar, also contains CuO in this material system₂Layer and Bi₂O ₂, can distinguish conduction electron and oxonium ion, this system also should have oxygen Select through performance.

Embodiment 2 YBa ₂Cu ₃O _6-xThe preparation of compact oxygen permeable film and measurement

YBa ₂Cu ₃O _6+xThe structure cell of material system contains CuO ₂Surface layer and CuO chain layer can be distinguished conduction electron and oxonium ion, thereby oxygen is had the selection through performance.

YBa ₂Cu ₃O _6+xThe compact oxygen permeable film preparation process is as follows: by the accurate weighing reactant of needed stoicheiometry cupric oxide, yittrium oxide and brium carbonate, be ground into fine powder, be pressed into cake, then 900 ℃ of calcinings 12-24 hour.For guaranteeing that solid-state reaction carries out fully, product is even, and the sample after the calcining need be pulverized again, grinding, mixing, cake of press, calcining again, can carry out repeatedly repeatedly in case of necessity, is verified as pure phase until the X-ray material phase analysis.To be pressed into flake shaped base substrate with the ceramic powder of method for preparing, and slowly be warming up to 930 ℃ of insulations 12-24 hour in air, cooling naturally promptly obtains YBa then ₂Cu ₃O _6+xCompact oxygen permeable film.

The sample that obtains is at first at room temperature checked to determine that it does not contain the connection pore, adopts its oxygen permeability of measurement device as shown in Figure 2 then.Introduce air at an end of film, can detect a large amount of oxygen at the other end of film, but the concentration of nitrogen is lower than detection range 5ppm, as seen this dense film has high selection through performance to oxygen.Thickness is that 1.4 millimeters oxygen permeation membrane can obtain pure oxygen and reaches 0.5m in the time of 800 ℃ ³M ^-2Day ^-1

Curve with " Δ " expression among Fig. 3 has provided YBa ₂Cu ₃O _6+xThe oxygen infiltration rate of compact oxygen permeable film and variation of temperature relation.Can significantly improve the permeability and separation efficient of its oxygen by the thickness that reduces oxygen permeable membrane with mixing.As the curve with " o " expression in the accompanying drawing 3 is YBa ₂Cu ₃O _6+xOxygen infiltration rate and variation of temperature relation behind the oxygen permeable film material doping Co element, its oxygen infiltration is than pure YBa ₂Cu ₃O _6-xCompact oxygen permeable film is significantly improved.In the time of 800 ℃, can obtain pure oxygen and reach 0.9m ³M ^-2Day ^-1

Because (Pb ₂Cu) Sr ₂A _N-1Cu _nO _2n+4(A=rare earth, Ca) system and YBa ₂Cu ₃O _6+xThe same CuO chain oxide ion conduction layer and the CuO of all containing of system ₂Face electronic conduction layer, different is that the CuO chain layer that this system contains is clipped among the two-layer PbO layer, constitutes the PbO-CuO-PbO composite bed.Because the PbO layer also can conduct oxygen ions, we have reason to infer (Pb ₂Cu) Sr ₂A _N-1Cu _nO _2n+4(A=rare earth, Ca) material system also has the oxygen infiltration function.

Claims (2)

1, a kind of metal oxide ceramic of compact oxygen-permeable separation membrane is characterised in that and adopts the layer structure material with special oxonium ion electrical conductivity characteristic, i.e. single-minded ground of some layer conduct oxygen ions in its cell configuration, and the other layer is conduction electron then single-mindedly; This class material comprises:

1), Bi ₂Sr ₂Ca _N-1Cu _nO _2n+4System, n=1-3 comprises with Pb, Sb partly substituting Bi, substitutes Sr with Ba or rare earth element, substitutes Ca with rare earth element y, substitutes Cu with transition-metal Fe, Co, Ni;

2), Bi ₂Sr ₂(R _1-xCe _x) ₂Cu ₂O ₁₀System, the R=rare earth element; X=0-0.3;

3), (Pb ₂Cu) Sr ₂A _N-1Cu _nO _2n+4System, A=rare earth, Ca; N=1,2.

2, a kind of ceramic of compact permeable membrane oxygen separator comprises that two air chambers centres add a dividing plate, are characterised in that described dividing plate is the described metal oxide ceramic of compact of claim 1 oxygen-permeable separation membrane.

Images