Application of a fluorine-doped perovskite membrane in oxygen separation

Abstract

The invention relates to application of a fluorine-doped perovskite-type membrane in oxygen separation. A membrane material is perovskite crystal form of oxyfluoride shown by a general formula AxA'1-xByB'1-yO3-gamma F delta, wherein the gamma represents the number of oxygen lattice defects, the A and the A' are any one of the elements Ce, Pr, Nd, Ca, Sr, Ba and La, the B and the B' are any one of the elements Co, Fe, Nb, Ta, Mo, W, Sc, Ti, Zr, Sn and Sb, 0 <= x <= 1, 0 <= y <= 1, and 0 <= gamma <= 1. The material is prepared by adopting a solid-phase reaction method, a uniaxial pressure method, a plastic extrusion method or a phase transformation method is adopted in the membrane forming process, the oxygen permeation capacity of the oxygen permeation membrane material can be remarkably improved by doping nonmetal fluorine, the high stability of the material at oxygen partial pressure is kept, and the fluorine-doped perovskite-type membrane further has excellent medium and low temperature performances, is suitable for long-term operation of low-temperature oxygen separation and meets the demand of industrial application.

Description

technical field

[0001] The invention belongs to the field of design and development of mixed conductor dense oxygen permeable membranes, in particular the application of a fluorine-doped perovskite membrane in oxygen separation. Background technique

[0002] Mixed conductor materials are a class of inorganic ceramic membrane materials that can simultaneously conduct oxygen ions and electrons, and are currently widely used in many fields such as pure oxygen preparation, solid oxide fuel cells, and membrane reactors. Utilizing the 100% selectivity of the mixed conductor oxygen permeable membrane to oxygen ions, it can be applied to the preparation of pure oxygen. In addition, replacing traditional air separation technologies such as cryogenic separation with mixed conductor oxygen permeable membrane technology can save nearly one-third of investment and operating costs. However, the biggest challenge currently faced by the mixed conductor oxygen permeation membrane technology...

Examples

Embodiment 1

[0027] Prepare material Ba of the present invention with solid state reaction method 0.5 Sr 0.5 co 0.8 Fe 0.2 o 3-δ f 0.1 As an example, the commercially available SrCO 3 , BaCO 3 ,Co 2 o 3 , Fe 2 o 3 , and SrF 2 After the powder is mixed, add ethanol, put it in a ball mill for 6 hours, rotate at a speed of 450rpm, and then dry it in static air. The dried powder is roasted in an air atmosphere at 900°C for 8 hours, and after grinding, a particle with a particle size of about 1 μm is obtained. Ba 0.5 Sr 0.5 co 0.8 Fe 0.2 o 3-δ f 0.1 Powder.

[0028] The powder was prepared under a uniaxial pressure of 200MPa to prepare a green film, and the heating rate was controlled to be 2°C / min. After the green film was sintered at 1050°C for 8 hours, the temperature was lowered to room temperature at a rate of 2°C / min. Type membrane (membrane thickness is 1mm). The surface micrograph of the membrane is shown in figure 1 . It can be seen from the figure that the membran...

Embodiment 2

[0033] Prepare material Pr of the present invention with solid state reaction method 0.2 Sr 0.8 Fe 0.9 Nb 0.1 o 3-δ f 0.4 As an example, the commercially available SrCO 3 , Pr 2 o 3 , Nb 2 o 5 , Fe 2 o3 , and FeF 3 After the powder is mixed, add ethanol, put it in a ball mill for 3 hours, rotate at a speed of 400rpm, and then dry it in static air. The dried powder is roasted in an air atmosphere at 1200°C for 10 hours, and after grinding, a powder with a particle size of about 5 μm is obtained. PR 0.2 Sr 0.8 Fe 0.9 Nb 0.1 o 3-δ f 0.4 Powder.

[0034] The hollow fiber membrane green body is prepared by the powder through the phase inversion method, and the heating rate is controlled at 4°C / min. After the membrane green body is sintered at 1300°C for 15 hours, the temperature is lowered to room temperature at a rate of 4°C / min, and the hollow fiber membrane is obtained. fibrous membranes, such as Figure 4 As shown, the thickness of the dense layer of the memb...

Embodiment 3

[0038] Prepare material La of the present invention with solid state reaction method 0.9 Ca 0.1 co 0.4 Mo .6 o 3-δ f 0.7 As an example, the commercially available CaCO 3 , La 2 o 3 ,Co 2 o 3 , MoO 3 , and CoF 3 After the powder is mixed, add ethanol, put it in a ball mill for 8 hours, rotate at a speed of 550rpm, and then dry it in static air. The dried powder is roasted in an air atmosphere at 1000°C for 5 hours, and after grinding, a particle with a particle size of about 200nm is obtained. La 0.9 Ca 0.1 co 0.4 Mo .6 o 3-δ f 0.7 Powder.

[0039] The powder is made of a tubular film green body by plastic extrusion, and the heating rate is controlled at 5°C / min. After the film green body is sintered at 1200°C for 20 hours, the temperature is lowered to room temperature at a rate of 5°C / min, and the tube is obtained. Type membrane

[0040] La 0.9 Ca 0.1 co 0.4 Mo .6 o 3-δ f 0.7 The X-ray diffraction test of the powder shows that it has a complete perovs...

technical field

[0001] The invention belongs to the field of design and development of mixed conductor dense oxygen permeable membranes, in particular the application of a fluorine-doped perovskite membrane in oxygen separation. Background technique

[0002] Mixed conductor materials are a class of inorganic ceramic membrane materials that can simultaneously conduct oxygen ions and electrons, and are currently widely used in many fields such as pure oxygen preparation, solid oxide fuel cells, and membrane reactors. Utilizing the 100% selectivity of the mixed conductor oxygen permeable membrane to oxygen ions, it can be applied to the preparation of pure oxygen. In addition, replacing traditional air separation technologies such as cryogenic separation with mixed conductor oxygen permeable membrane technology can save nearly one-third of investment and operating costs. However, the biggest challenge currently faced by the mixed conductor oxygen permeation membrane technology...

Examples

Embodiment 1

[0027] Prepare material Ba of the present invention with solid state reaction method 0.5 Sr 0.5 co 0.8 Fe 0.2 o 3-δ f 0.1 As an example, the commercially available SrCO 3 , BaCO 3 ,Co 2 o 3 , Fe 2 o 3 , and SrF 2 After the powder is mixed, add ethanol, put it in a ball mill for 6 hours, rotate at a speed of 450rpm, and then dry it in static air. The dried powder is roasted in an air atmosphere at 900°C for 8 hours, and after grinding, a particle with a particle size of about 1 μm is obtained. Ba 0.5 Sr 0.5 co 0.8 Fe 0.2 o 3-δ f 0.1 Powder.

[0028] The powder was prepared under a uniaxial pressure of 200MPa to prepare a green film, and the heating rate was controlled to be 2°C / min. After the green film was sintered at 1050°C for 8 hours, the temperature was lowered to room temperature at a rate of 2°C / min. Type membrane (membrane thickness is 1mm). The surface micrograph of the membrane is shown in figure 1 . It can be seen from the figure that the membran...

Embodiment 2

[0033] Prepare material Pr of the present invention with solid state reaction method 0.2 Sr 0.8 Fe 0.9 Nb 0.1 o 3-δ f 0.4 As an example, the commercially available SrCO 3 , Pr 2 o 3 , Nb 2 o 5 , Fe 2 o3 , and FeF 3 After the powder is mixed, add ethanol, put it in a ball mill for 3 hours, rotate at a speed of 400rpm, and then dry it in static air. The dried powder is roasted in an air atmosphere at 1200°C for 10 hours, and after grinding, a powder with a particle size of about 5 μm is obtained. PR 0.2 Sr 0.8 Fe 0.9 Nb 0.1 o 3-δ f 0.4 Powder.

[0034] The hollow fiber membrane green body is prepared by the powder through the phase inversion method, and the heating rate is controlled at 4°C / min. After the membrane green body is sintered at 1300°C for 15 hours, the temperature is lowered to room temperature at a rate of 4°C / min, and the hollow fiber membrane is obtained. fibrous membranes, such as Figure 4 As shown, the thickness of the dense layer of the memb...

Embodiment 3

[0038] Prepare material La of the present invention with solid state reaction method 0.9 Ca 0.1 co 0.4 Mo .6 o 3-δ f 0.7 As an example, the commercially available CaCO 3 , La 2 o 3 ,Co 2 o 3 , MoO 3 , and CoF 3 After the powder is mixed, add ethanol, put it in a ball mill for 8 hours, rotate at a speed of 550rpm, and then dry it in static air. The dried powder is roasted in an air atmosphere at 1000°C for 5 hours, and after grinding, a particle with a particle size of about 200nm is obtained. La 0.9 Ca 0.1 co 0.4 Mo .6 o 3-δ f 0.7 Powder.

[0039] The powder is made of a tubular film green body by plastic extrusion, and the heating rate is controlled at 5°C / min. After the film green body is sintered at 1200°C for 20 hours, the temperature is lowered to room temperature at a rate of 5°C / min, and the tube is obtained. Type membrane

[0040] La 0.9 Ca 0.1 co 0.4 Mo .6 o 3-δ f 0.7 The X-ray diffraction test of the powder shows that it has a complete perovs...

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