STEAM REFORMING OF SOLID CARBON IN PROTONIC CERAMIC FUEL CELLS

摘要

A process for converting a carbon containing fuel (120) and water vapor (116) into a reformate gas that includes hydrogen, carbon monoxide (122) and carbon dioxide, using water molecules that diffuse through a membrane by steam permeation reforming. The process includes providing a ceramic membrane (112) comprising an oxide ceramic having intrinsic and extrinsic oxygen ion vacancies (110), and having first and second surfaces; where the oxide ceramic capable of reacting with gaseous water molecules at the first surface by the reversible reaction, H2O(g) + Vo<..> + Oo 2 OH<.>o; and the oxide ceramic capable of producing gaseous water molecules at the second surface by the reversible reaction, 2 OH<.>o H2O(g) + Vo<..> + Oo; contacting water vapor with the first surface; contacting the refonmate gas with the second surface, whereby solid state ambipolar diffusion of oxygen ion vacancies and protons across the membrane occurs; and the ambipolar diffusion produces a net diffusion flux of water molecules through the membrane from the first surface to the second surface.