Membrane-based reactive separations for power generation applications: Oxygen lancing

O₂ lancing is one of the industrial techniques for implementing oxygen-enhanced combustion (OEC), and can potentially result in stable combustion with reduced NO_x emissions. The key technical challenge facing lancing (and OEC in general) is the significant cost of O₂ enrichment. The present work reports early results from a study of CH₄ OEC, in which the O₂ enrichment of air is implemented in situ using dense, high-temperature mixed-conducting solid-oxide membranes. We report on the preparation and characterization of these membranes, and on the fundamental combustion studies of the relevant reactive mixtures, including the effect of O₂ lancing on the NO_x and CO emissions of fuel-lean and fuel-rich CH₄/air premixed flames.