Ce_0.8Y_0.2O_2--BaCe_0.8Y_{0 .2}O_3- Dual-Phase Hollow Fiber Membranes for Hydrogen Separation

Partial oxidation of methane (POM) is a prominent pathway for syngas production, wherein the hydrogen in syngas product can be recovered directly from the reaction system using a hydrogen (H-2)-permeable membrane. Enhancing the efficiency of this H-2 separation process is a current major challenge. In this study, Ce0.8Y0.2O2-delta-BaCe0.8Y0.2O3-delta (YDC-BCY) hollow fiber (HF) membranes were developed and characterized for their H-2 permeation fluxes. Firstly, YDC and BCY ceramic powders were synthesized using the sol-gel method, followed by the fabrication of YDC-BCY dual-phase ceramic HF membranes using a combined phase inversion-sintering process. Characterization using SEM, powder XRD, EDS, and electrical conductivity tests confirmed the phases of the prepared powders and HF membranes. Well-structured YDC and BCY powders with uniform particle sizes were obtained after calcination at 900 C-degrees. With the addition of 1 wt.% Co2O3 as a sintering aid, the YDC-BCY dual-phase HF membrane achieved densification after sintering at 1500 C-degrees. Subsequently, the influences of sweep gas composition and temperature on the hydrogen permeation of the YDC-BCY HF membranes with YDC/BCY molar ratios of 2:1, 3:1, and 4:1 were investigated. At 1000 C-degrees and a sweep-gas flow rate of 120 mL center dot min(-1), the YDC-BCY HF membrane with a YDC/BCY molar ratio of 4:1 exhibited a peak hydrogen flux of 0.30 mL center dot min(-1) cm(-2). There is significant potential for improving the hydrogen permeation of dual-phase ceramic membranes, with future efforts aimed at reducing dense layer thickness and enhancing the membrane material's electronic and proton conductivities.