Performance of a ceramic membrane reactor with high oxygen flux Ta-containing perovskite for the partial oxidation of methane to syngas

A novel dense BaCo_0.7Fe_0.2Ta_0.1O_3-δ (BCFT) perovskite membrane was successfully synthesized from BaCO₃, Co₂O₃, Fe₂O₃ and Ta₂O₅ by a simple solid state reaction. X-ray diffraction (XRD) was used to characterize the phase formation process of BCFT precursors after ball-milling 24 h in ethanol and calcining at different temperatures. The oxygen permeation under different driving forces shows that the oxygen permeation under an air/He oxygen gradient is controlled by bulk diffusion at 900 °C for a membrane thickness from 0.6 mm to 1.2 mm. However, the oxygen permeation under the stronger oxygen gradient in the partial oxidation of methane (POM) to syngas reaction at 900 °C is limited by the oxygen surface exchange. The POM to syngas in the BCFT reactor was successfully performed. Methane conversion was found to be >99% with 94% CO selectivity and 16.2 ml/min cm² oxygen permeation flux under a steady state condition was obtained at 900 °C. Moreover, the BCFT membrane reactor has been steadily operated in the POM to syngas reaction for more than 400 h without any fractures.