Impact of extrusion parameters on the mechanical performance of tubular BSCF-supports for asymmetric oxygen transporting membranes

Abstract

Abstract Tubular asymmetric membranes based on BSCF (Ba0.5Sr0.5Co0.8Fe0.2O3-δ) are well-known for high O2 permeability, but there use in first pilot plants for small scale O2 production is constricted by low fracture strength. Therefore, ceramic shaping of porous support tubes by extrusion was optimized to improve mechanical properties, especially fracture strength. Accordingly, content of pore forming agent, kneading time and rotational speed of the main extrusion screw were varied, systematically. Microstructure and fracture strength were characterized and compared to reference samples manufactured using a common set of extrusion parameters. It is demonstrated that a notable improvement of mechanical strength could be achieved by even small adjustments of the individual parameters mentioned in this work. In addition, the received results allowed to discuss influence of rotational speed of the main extrusion screw on the behavior of the extruded mixture, as well as, sintering behavior of ceramic structures containing large pores, in more detail.