Design and Fabrication of Novel Mixed Ion-Electron Conducting Membranes for Oxygen Separation

For a gasification based energy system the cost of the air separation unit represents 12 – 15% of the installed capital costs and requires a significant amount of power resulting in lowered operational efficiencies. Consequently, there is a significant opportunity for lowered capital costs and improved operating efficiencies for new oxygen generation technologies that can replace existing cryogenic systems. One of the most promising new technologies under development currently is advanced ion-electron mixed conductors (IEMC) for oxygen separation from air. Statement of how this Problem or Situation is Being Addressed To advance IEMC technology, the potential for significant reductions in operation cost and for improving efficiency is improved oxygen permeation rates through the IEMC membrane. The primary ways to achieve that goal are decreasing the membrane thickness, developing a new material with higher ionic conductivities than current materials, improving the surface kinetics of the electrode reactions and/or lowering the cost of manufacture for producing these complex membrane structures. In this proposed project, HiFunda and Georgia Institute of Technology will develop a new IEMC membrane material with improved ionic conductivity and surface kinetics over state of the art materials in conjunction with improvements in the manufacturing process through advancements in plasma spray technology. Commercial Applications and Other Benefits The two main applications of high temperature membrane technology are the production of high purity oxygen as a valuable chemical and as a reactant for various (partial) oxidation processes such as methane conversion. The IEMC technology is in direct competition with the well-established and energy intensive cryogenic distillation. Process engineering and economic evaluations of IGCC power plants comparing IEMC membrane based oxygen production against cryogenic air separation found significant overall benefits for using the IEMC membrane. IEMC membrane units were projected to decrease the installed capital cost of air separation equipment by over a third and the installed capital cost of an IGCC facility by 7%, while improving efficiency and reducing the power requirement for air separation by approximately 35%. This efficiency increase also produces an associated reduction in carbon dioxide and sulfur emissions. These benefits will be translated to the public through lower cost for goods and services in addition to lower cost energy. Finally, making low cost oxygen available in these industries results in cleaner power production and reduced emissions of polluting gases.