Design, Fabrication, and Characterization of Porous Yttria-Stabilized Zirconia Ceramics for Hot Gas Filtration Applications

Hot gas filtration is a lucrative target for a number of high temperature industrial operations, but new materials must be developed to withstand intense high temperature conditions. Here, the authors put the emphasis on porous yttria-stabilized zirconia (YSZ) ceramics for hot gas filtration, owing to their high thermodynamic stability and toughness. The authors design and fabricate porous YSZ ceramics using a pore-forming inclusion technique, where a polymeric pore former is mixed and compacted with YSZ powder. After burning off, the polymer leaves behind a controlled amount of porosity before sintering commenced. The authors systematically investigate the sintering temperature, polymer particle size, and polymer-to-ceramic ratio to optimize the open porosity, pore size, gas permeability, and hardness of porous YSZ ceramics. The authors then evaluate the performance of porous YSZ ceramics under industrial conditions by cyclic heating/cooling testing and high temperature exposure testing. The authors show, for the first time, porous YSZ ceramics can perform in hot gas filtration applications at 1400 degrees C for extended thermal cycling or at 1700 degrees C for limited periods of time.