Hydrogen Purification through a Highly Stable Dual-Phase Oxygen-Permeable Membrane

Using oxygen permeable membranes (OPMs) to upgrade low-purity hydrogen is a promising concept for high-purity H-2 production. At high temperatures, water dissociates into hydrogen and oxygen. The oxygen permeates through OPM and oxidizes hydrogen in a waste stream on the other side of the membrane. Pure hydrogen can be obtained on the water-splitting side after condensation. However, the existing Co- and Fe-based OPMs are chemically instable as a result of the over-reduction of Co and Fe ions under reducing atmospheres. Herein, a dual-phase membrane Ce0.9Pr0.1O2-delta-Pr0.1Sr0.9Mg0.1Ti0.9O3-delta (CPO-PSM-Ti) with excellent chemical stability and mixed oxygen ionic-electronic conductivity under reducing atmospheres was developed for H-2 purification. An acceptable H-2 production rate of 0.52 mL min(-1) cm(-2) is achieved at 940 degrees C. No obvious degradation during 180 h of operation indicates the robust stability of CPO-PSM-Ti membrane. The proven mixed conductivity and excellent stability of CPO-PSM-Ti give prospective advantages over existing OPMs for upgrading low-purity hydrogen.

Automated summary

The development of a dual-phase membrane with excellent chemical stability and mixed conductivity for hydrogen purification at high temperatures has shown the potential for stable production of high-purity hydrogen.