Low cost porous MgO substrates for oxygen transport membranes

This paper delineates the fabrication of porous magnesium oxide (MgO) ceramics with high porosity and gas permeability by warm pressing using pre-calcined MgO powder and fugitive pore former (combination of graphite and polymethyl methacrylate). Effect of pore former on the microstructure development of porous MgO ceramic substrates was subjected to investigation. The resultant microstructure consisted of large spherical and elongated pores with small interconnecting pores. The total porosity (55%), mean pore neck size (0.65 µm), and the associated gas permeability (4-4.5×10−15 m2) of MgO substrates were measured and correlated. Economic analysis of the MgO substrates was performed and it was found that MgO was much cheaper compared to perovskite and fluorite materials.