Separation and Purification Technology, Vol.213, 515-523, 2019
Hydrogen permeation performance of dual-phase protonic-electronic conducting ceramic membrane with regular and independent transport channels
This work characterizes the hydrogen permeation fluxes of dual-phase SrCe0.9Y0.1O3-Ce0.8Sm0.2O2 (SCY-SDC) laminated membrane that contains regular and independent transport channels made of alternating films of SCY and SDC phases. Such membrane was synthesized via combined tape casting, co-pressing, and sintering route. The hydrogen flux of the dual-phase SCY-SDC laminated membrane reached 0.163 mL min(-1) cm(-2) at 900 degrees C when 100 mL min(-1) of 20 vol% H-2 in He and 100 mL min(-1) of N-2 were passed in the feed side and the permeate side, respectively. Such flux is significantly larger than the flux of the conventional SCY-SDC dual-phase membrane made by mixing SCY-SDC powder mixture and subsequent sintering at the same operation condition. The enhanced flux for the dual-phase laminated membrane relative to the conventional dual-phase membrane is attributed to the shorter diffusion paths for protons and electrons and the lower amount of the phase interfaces. The dual-phase SCY-SDC laminated membrane also displayed stable hydrogen permeation flux of around 0.15 mL min(-1) cm(-2) during 166-hour continuous operation at 850 degrees C in the presence of carbon dioxide in the permeate gas stream. Such stable performance highlights its chemical stability. Another attractive advantage of the dual-phase SCY-SDC laminated membrane lies in the minor discrepancy of the thermal expansion coefficient of SCY (alpha = 1.12.10(-5) K-1) to that of SDC (alpha = 1.28.10(-5) K-1) as obtained by dilatometry from room temperature to 1500 degrees C, which ensures its mechanical integrity during repeated thermal cycles.