Abstract: A process for regulating the rate of permeation of oxygen through a nonporous ceramic membrane which conducts oxygen anions and contains alkaline earth metal ions. On at least one side of the nonporous ceramic membrane which conducts oxygen anions, carbon dioxide and/or a gaseous carbon dioxide precursor is added for a predetermined time, which enables an alteration of the oxygen permeability of the membrane material. This brings about reversible chemical formation of alkaline earth metal carbonates in the membrane and, as a result, alters the properties thereof for oxygen permeation. A membrane reactor equipped with a feed line for a moderator gas can be regulated in a simple manner. The membrane reactor can preferably be used for oxidation reactions and/or for removal of oxygen from gas mixtures.

Abstract: Composites comprising at least one hollow fiber of oxygen-transporting ceramic material, which is a ceramic material which conducts oxygen anions and electrons or a combination of ceramic material which conducts oxygen anions and a ceramic or nonceramic material which conducts electrons, with the outer surface of the hollow fiber being in contact with the outer surface of the same hollow fiber or another hollow fiber and the contact points being joined by sintering, are described. Further composites comprise at least one hollow fiber of oxygen-transporting ceramic material which is a ceramic material which conducts oxygen anions and electrons or a combination of ceramic material which conducts oxygen anions and ceramic or nonceramic material which conducts electrons and a connection element for the introduction or discharge of fluids at at least one end face, with hollow fibers and connection element being joined.

Abstract: A process for enriching the content of oxygen in oxygen- and nitrogen-containing gases in a separation apparatus which has an interior which is divided into a substrate chamber and into a permeate chamber by an oxygen-conducting ceramic membrane is described. The process comprises the introduction of oxygen- and nitrogen-containing sweep gas into the permeate chamber and the establishment of a pressure in the substrate chamber so that the oxygen partial pressure in substrate chamber and sweep chamber results in the transfer of oxygen through the ceramic membrane. The process is distinguished by high operational safety.

Abstract: The invention relates to an oxidation reactor and process suited to operate the said reactor which houses a multitude of gas-tight and oxygen conductive membrane elements the external surfaces of which are arranged on the side of a reaction chamber to be filled with catalyst and which constitute, in conjunction with the membrane elements penetrable by oxygenous gas, a connection between the distribution chamber and a collection chamber and/or discharge section of the reactor. The reactor is characterised in that one or several spacer pieces establish a defined minimum distance between the external surface of a membrane element and the catalyst in the reaction chamber.

Abstract: Composites comprising at least one hollow fibre of oxygen-transporting ceramic material, which is a ceramic material which conducts oxygen anions and electrons or a combination of ceramic material which conducts oxygen anions and a ceramic or nonceramic material which conducts electrons, with the outer surface of the hollow fibre being in contact with the outer surface of the same hollow fibre or another hollow fibre and the contact points being joined by sintering, are described. Further composites comprise at least one hollow fibre of oxygen-transporting ceramic material which is a ceramic material which conducts oxygen anions and electrons or a combination of ceramic material which conducts oxygen anions and ceramic or nonceramic material which conducts electrons and a connection element for the introduction or discharge of fluids at at least one end face, with hollow fibres and connection element being joined.