Oxygen separation through U-shaped hollow fiber membrane using pure CO₂ as sweep gas

Abstract

<jats:title>Abstract</jats:title><jats:p>A number of U‐shaped K<jats:sub>2</jats:sub>NiF<jats:sub>4</jats:sub>‐type oxide hollow fiber membranes based on (Pr<jats:sub>0.9</jats:sub>La<jats:sub>0.1</jats:sub>)<jats:sub>2</jats:sub>(Ni<jats:sub>0.74</jats:sub>Cu<jats:sub>0.21</jats:sub>Ga<jats:sub>0.05</jats:sub>)O<jats:sub>4+δ</jats:sub> (PLNCG) were successfully prepared by a phase inversion spinning process. The PLNCG hollow fiber membranes were then used to investigate the effect of CO<jats:sub>2</jats:sub> concentration in both the sweep gas and the feed air on the oxygen permeation flux. With pure CO<jats:sub>2</jats:sub> as the sweep gas and even 10% CO<jats:sub>2</jats:sub> in the feed air, a steady oxygen permeation flux of 0.9 mL/min<jats:sup>·</jats:sup>cm<jats:sup>2</jats:sup> (STP) is obtained at 975°C during 310 h, and no decline of the oxygen permeation flux is observed. XRD, SEM and EDS characterizations show the spent membrane still maintains the intact microstructure and perfect K<jats:sub>2</jats:sub>NiF<jats:sub>4</jats:sub>‐type phase structure without carbonate, which indicates that the U‐shaped PLNCG hollow fiber membrane is a very stable membrane under CO<jats:sub>2</jats:sub> atmosphere and has great potential for the practical application in oxyfuel techniques for CO<jats:sub>2</jats:sub> capture and storage.©2011 American Institute of Chemical Engineers AIChE J, 2012</jats:p>