YBaCo4O7+delta has been reported to have a large oxygen capacity which can be accessed on practical timescales by both temperature and pressure swings below 400 degrees C. One potential use of this oxygen capacity is for oxygen enrichment of process gas streams for e.g. application in oxy-fuel combustion and auto-thermal reforming. In this work, YBaCo4O7+delta powders were produced by a solid state synthesis and their material properties studied with a view to use as a process stream oxygen enricher. The stability of the material as a function of temperature in both CO2 and reducing gases (CO and H-2) was investigated. The kinetics of oxygen uptake and release was studied by following the response to swings in oxygen partial pressure (pO(2)) and temperature. To demonstrate the potential for employing this reversible oxygen capacity, the material was successfully used to supply oxygen into a gas stream with a pO(2) of 0.31 bar after oxidation in an air stream (pO(2) = 0.21 bar).