Abstract: A method of separating oxygen from an oxygen containing stream in which compressed and heated oxygen is introduced into cathode side of an oxygen transport membrane reactor. Oxygen is permeated from the cathode side to the anode side. Motive fluid that is introduced into an ejector draws an oxygen permeate containing stream from the anode side at a subatmospheric pressure to form an oxygen containing product stream. The motive fluid, which can be steam raised by combustion used in heating the reactor, can be separated from the oxygen containing product stream to form an oxygen product stream. The use of an ejector lowers the partial pressure of the oxygen at the anode side of the membrane reactor and therefore the degree to which the oxygen containing stream need be compressed.

Abstract: A method of separating oxygen using a ceramic membrane unit having one or more ceramic membranes, preferably formed of a mixed conducting ceramic, for instance, a perovskite, capable of conducting both oxygen ions and electrons. Oxygen is separated within the ceramic membrane unit under impetus of compressing an incoming oxygen containing feed. The compressor used in the compression is powered by the work of expansion produced by expanding a process stream composed of at least a portion of the retentate produced in the ceramic membrane unit. Prior to expansion, the process stream is cooled to allow the use of less expensive materials in expanders used in the expansion. As a result, expansion of the process stream alone is insufficient to meet the power requirements involved in the compression. Interstage expansion with reheating is used to make up for the power deficit.

Abstract: A method of separating oxygen from an oxygen containing gas using an ceramic membrane unit having one or more ceramic membranes, preferably formed of a mixed conducting ceramic capable of conducting both oxygen ions and electrons. Oxygen is separated within the ceramic membrane unit under impetus of compressing the incoming feed. Sufficient power for such compression is created through expansion of a process stream composed in part of the retentate with interstage expansion reheating.