Ceramic Membrane Technologies for Oxygen Separation

Abstract

Solid‐state electrochemical cells based on oxygen‐ion conduction (pure ionic or mixed ionic/electronic conductors) allow selective transport of oxygen (oxygen‐ion conducting materials) in the form of ionic flux at high temperatures. Thus these systems can act as filters for molecular oxygen and can be used for both generation or removal of oxygen selectively. The usage of such devices are numerous, including production of high purity oxygen for medical applications, aqua‐culture and combustion processes; control of oxygen partial pressure in industrial environments; production of power and chemicals; and removal of oxygen from enclosures and gas streams. In this paper, a brief overview of the technology has been given and various membrane materials for construction of such devices have been discussed.

Oxygen permeation through perovskite membranes and the improvement of oxygen flux by surface modification

“…Current tonnage O 2 production by cryogenic processes is very energy expensive and production cost reduction by 35% or more is required [1][2][3][4], which in turn is driving academic and industrial researchers toward membrane technology development for the last decade. Of particular attention, ion conducting ceramic membranes have attracted the attention of the research community, with over 20 laboratories worldwide conducting research on the subject.…”

“…For this purpose, EDTA powder (with a ratio of 29.2 g EDTA to 75 mL ammonia) was added under magnetic stirring into aqueous ammonium hydroxide (28.0-30.0%) to form a water-soluble ammonium salt. In a separate beaker stoichiometric quantities of Ba(NO 3 ) 2 , Sr(NO 3 ) 2 , Co(NO 3 ) 2 , Fe(NO 3 ) 3 , and citric acid in granular form were dissolved in distilled water. The EDTA solution was then added into the solution of the metal ions and citric acid under stirring.…”

Oxygen ionic conduction in brownmillerite CaAl0.5Fe0.5O2.5+

“…Mixed-conducting oxide materials have promising applications in high-temperature electrochemical devices, such as ceramic membranes for oxygen separation and partial oxidation of hydrocarbons, electrodes of solid oxide fuel cells (SOFCs), and sensors [1][2][3][4][5]. A high level of oxygen ionic conductivity is characteristic of perovskite-type ferrites derived from AFeO 3Àd , where A corresponds to the alkaline earth cations [1,[4][5][6].…”

A novel CO2-stable dual phase membrane with high oxygen permeability

“…Oxygen transporting membranes (OTMs) 2 based on mixed electronic and ionic conductors, can supply oxygen of 100% purity to power stations for CO 2 capture according to the oxyfuel for CO 2 capture and storage. 3 The oxyfuel concept involves the combustion of fossil fuels with an oxygen/exhaust gas mixture.…”

“…4 A part of the exhaust gas CO 2 is sequestrated, and another part is recycled and used as sweep gas for the oxygen separation through the OTMs. Thus, the OTMs for CO 2 capture in the oxyfuel process should have not only good stability in a CO 2 atmosphere but also high oxygen permeation performance at elevated temperatures. Moreover, OTMs can be used in many promising potential applications, such as in high-purity oxygen production, 5 in catalytic membrane reactors, 6 and as cathodes in solid oxide fuel cells (SOFCs).…”