The Preparation And Property Of Dual-Phase Mixed Conductor Ceramic Oxygen-permeable Membrane

Nowadays,Oxygen,as an important chemical,is applied to various aspects of life,the processing and industrial production of fossil fuels also consumes a lot of oxygen.The demand for oxygen comes from metallurgical,chemical,defense,and medical applications,etc.Now the oxygen production technology mainly contains air liquefaction and distillation and pressure swing adsorption,however,the cost of air liquefaction and distillation technology is so high which consumes a lot of energy,while the method of pressure swing adsorption is difficult to get pure oxygen.So it is time to explore another new oxygen separation technology to meet the needs of society.The ceramic mixed conductor membrane is a new type of oxygen producing technology.In this context,the ceramic permeable membrane is studied in this paper.In the first part,the research background,basic principle and typical application of ceramic oxygen separation membrane are reviewed,and the research and development of ceramic membrane permeable membrane are also introduced.The preparation methods of powder and ceramic membrane and the classification of ceramic morphology were summarized.In the second part,the equipment and reagents and characterization methods used in the experiment are introduced.In this paper a kind of oxygen transmission device was designed,which was using the principle of the oxygen sensor,and the oxygen permeation rate of ceramic permeable membrane was measured by this device.The theoretical formula of oxygen permeation is derived from theoretical calculation,and the oxygen permeability of ceramic permeable membrane was verified by the formula,it proves that the theory conforms to the reality.In the third part,La?15??13??23?Sr?15??13??17?Cr?15??13??20?Fe?15??13??20?O_3-??LSCrF?powder was prepared by EDTA-citrate complexing sol-gel method,which is used as the electronic conducting phase,Ce?15??13??23?Sm?15??13??17?O?16??13??24??SDC?was used as the oxide ion conductor.Gas-tight SDC-LSCrF dual-phase composite ceramic film with 3mol%Y?17?O?18?stable Zr O?17??3YSZ?support was prepared by screen printing technique and tested as an oxygen separation membrane.The powder was characterized using X-ray diffraction?XRD?and the dual-phase composite ceramic oxygen separation membrane is analyzed using scanning electron microscope?SEM?to observe the microstructure of membrane.Finally the oxygen transmission performance was tested by electrochemical method.The results show that the sol-gel method could produce single phase powder of LSCrF,and the oxygen partial pressure,temperature and the thickness of ceramic membrane all have influence on the oxygen permeation rate.When air was used as sweeping gas on the porous 3YSZ-supported SDC-LSCrF dual-phase membrane,the oxygen permeation rate was 7.40×10^-7,9.00×10^-7 and 1.24×10^-6mol cm^-2 s^-1 at 700,750 and800?,respectively.In the fourth part,Bi?15??13??22?Er?15??13??18?O?18??ESB?powder was prepared by solid reaction method and is used as the oxide ion conducting phase.Combining with La?15??13??23?Sr?15??13??17?MnO?18??LSM?as the electronic conducting phase,ESB–LSM dual-phase oxygen permeable membrane was prepared by press and sintering.The phase of ESB and its compatibility with LSM was characterized using X-ray diffraction?XRD?and the microstructure of the dual-phase composite ceramic oxygen separation membrane is observed using scanning electron microscope?SEM?.Finally,the oxygen transmission performance was tested by an electrochemical method.The results show that the solid reaction method could produce single phase powder of ESB.The oxygen partial pressure,temperature and the ratio of oxide ion and electron conductive phases all have influence on the oxygen permeation rate through the ceramic membrane.When air was used as sweeping gas on the ESB–LSM dual-phase membrane,with mass ratio of 8:2,the oxygen permeation rate was 1.95×10^-7,2.33×10^-7,2.90×10^-7 and 3.37×10^-77 mol cm^-2 s^-1 at 650,700,750 and 800?,respectively.The fifth part summarizes the research work of this thesis,and The application prospect and main challenges of dual-phase hybrid conductor ceramic permeable membrane were prospected.