Abstract
A dense membrane consisting of two-phases: molten carbonate for the conduction of carbonate ions and Bi 1.5Y 0.3Sm 0.2O 3 (BYS) for the conduction of oxygen ions, was synthesized and used for selective permeation of CO 2 at high temperatures. Since CO 2 is transported by CO 3 2-, these membranes provide infinite selectivity for CO 2 over other species such as Ar, He or N 2.The dual-phase membranes were synthesized by the direct infiltration molten carbonate into porous BYS supports with internal surface modified with γ-Al 2O 3 to improve the wettability. Permeation took a long time to reach a steady state at the initial stage of high temperature CO 2 separation due to the reversible phase transform of the oxygen ions conduction phase between the rhombohedral structure and cubic fluorite structure. The CO 2 permeation flux for the dual phase membrane increases with increasing temperature (500-650°C) with apparent activation energy for CO 2 permeation of 113.4kJ/mol. The CO 2 permeation flux increases with increasing sweep gas flow rate and reaches a value of 0.083mL/cm 2/min at 650°C and helium flow rate of 125mL (STP)/min. The BYS-carbonate membrane offers higher CO 2 permeance than carbonate dual-phase membranes with lithium-cobaltite or yttrium stabilized zirconia as the oxygen ionic conducting phase.
Original language | English (US) |
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Pages (from-to) | 174-182 |
Number of pages | 9 |
Journal | Journal of Membrane Science |
Volume | 417-418 |
DOIs | |
State | Published - Nov 1 2012 |
Keywords
- CO permeation
- Dual-phase membranes
- Oxygen ionic conductivity
- Phase change
- Wettability
ASJC Scopus subject areas
- Biochemistry
- Materials Science(all)
- Physical and Theoretical Chemistry
- Filtration and Separation