Perovskite/Oxide Composites as Mixed Protonic/Electronic Conductors for Hydrogen Recovery in IGCC Systems

70103 Integrated Gasification Combined Cycle (IGCC) systems are promising new alternatives for highly efficient and environmentally friendly power generation. In order to make these systems commercially viable, a portion of the hydrogen from syngas needs to be recovered as a value-added byproduct through the use of hydrogen separation membranes such as proton-conducting membranes. Since current membrane technologies for hydrogen separation are incompatible with the high-temperature, high-pressure environment in IGCC systems, robust and efficient membrane systems are required. This project will develop a novel, dense, ceramic-composite membrane that will function as a mixed protonic/electronic conductor under expected IGCC operating conditions. These mixed-conducting composite membranes will allow pressure-driven hydrogen separation at 800-900oC, at higher flux-rates than is possible with single phase membranes, resulting in a very high purity hydrogen stream. Phase I will demonstrate the feasibility of the dense mixed-conducting ceramic composite concept. An appropriate second phase, which is thermodynamically compatible with ceramic protonic conductors such as barium or strontium cerates, will be selected. The hydrogen separation membrane will be fabricated and operated under simulated operating conditions. Commercial Applications and Other Benefits as described by the awardee: The hydrogen separation membrane should have a major impact on enhancing the commercial feasibility of IGCC systems and other industrial hydrogen recovery/separation processes. Further, this membrane should also be applicable to such emerging technologies as intermediate-temperature fuel cells based on proton-conducting electrolytes.