Production of pure oxygen from BSCF hollow fiber membranes using steam sweep

► Oxygen flux increased as a function of the steam sweep flow rate and temperature, reaching 9.52 ml min−1 cm−2 at 950 °C. ► Oxygen flux remained stable up to 20 h, though undergoing a significant reduction afterwards, while oxygen purity reduced after 40 h testing. ► Steam leached the elements of BSCF, mainly forming an extra porous layer of insoluble carbonates of barium and strontium. ► Carboxylic acid ever present in steam, in addition to steam at high temperatures, deteriorated the BSCF over long exposures in excess of 40 h.