New miec membranes for hydrogen separation

Abstract

A new approach to separate hydrogen using dual phase composite MIEC membranes has been proposed and is being currently investigated. In this approach methane or reformate comprising CO and H2 mixtures is fed to one side of the membrane, while water vapor is fed to the other side. Oxygen from the steam side of the membrane transports through coupled transport of oxygen ions and electrons across the membrane to the methane/reformate side resulting in a hydrogen rich product on the permeate side. Although single phase membranes such as strontium or calcium doped lanthanum cobalt kon oxides (LSCF and LCF) have very high mixed conductivity, they were found to be not stable for the process under investigation. New dual phase membranes consisting of doped ceria and doped strontium titanate have been developed with good stability and high ambipolar conductivity suitable for the permeation process.