Enhanced CO2 separation via molten-carbonate membranes with freeze-cast, porous ceramic supports

Molten-carbonate membranes with freeze-cast, porous ceramic supports were fabricated and tested for high temperature CO 2 separation. The freeze-casting fabrication method resulted in highly porous and hierarchically organized ceramic supports. The versatility of the freeze-casting method was demonstrated by fabricating ionic (oxide-ion) and mixed ionic-electronic conducting membrane supports, namely, La 0.58 Sr 0.4 Fe 0.8 Co 0.2 O 3− δ (LSFC), Ce 0.8 Gd 0.2 O 1.9 (CGO) and Y 0.2 Zr 0.8 O 1.9 (YSZ). The resulting membranes showed very high CO 2 permeance, achieving maximum values of ∼1.5 × 10 −7 mol Pa −1 s −1 m −2 at 850 °C. The gas permeation results demonstrated that the pore microstructure resulting from freeze-casting provides higher CO 2 permeances than membranes fabricated from the same materials, but using other fabrication methods, in the literature.