Ce_0.8Y_0.2O_2-δ-BaCe_0.8Y_0.2O_3-δ Dual-Phase Hollow Fiber Membranes for Hydrogen Separation

Abstract

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 (H2)-permeable membrane. Enhancing the efficiency of this H2 separation process is a current major challenge. In this study, Ce0.8Y0.2O2-δ-BaCe0.8Y0.2O3-δ (YDC-BCY) hollow fiber (HF) membranes were developed and characterized for their H2 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. 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. 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 and a sweep-gas flow rate of 120 mL·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·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.

Keywords

• sintering aid
• sol-gel
• phase inversion
• dual-phase
• syngas
• POM