Rapid glycine-nitrate combustion synthesis of the CO2-stable dual phase membrane 40Mn1.5Co1.5O4-δ-60Ce0.9Pr0.1O2-δ for CO2 capture via an oxy-fuel process

A rapid one-pot combustion synthesis method based on glycine-nitrate, has been applied to prepare a novel oxygen transporting dual phase CO2-stable membrane of the composition 40 wt% Mn1.5Co1.5O4-delta-60 wt% Ce0.9Pr0.1O2-delta(40MCO-60CPO). After sintering at 1300 degrees C in air for 10 h, the 40MCO-60CPO membranes were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), back scattered SEM (BSEM), and energy dispersive X-ray spectroscopy (EDXS), showing that the 40MCO-60CPO composite represents a micro-scale mixture of mainly the two phases MCO and CPO, but small amounts of MnO2 and (MnCo)(MnCo)(2)O4-delta were detected in the sintered membranes as well. The oxygen permeation fluxes through the 40MCO-60CPO dual phase membrane were measured at elevated temperatures (900-1000 degrees C) with one side of the membrane exposed to synthetic air and the other side to a CO2/He sweep gas stream. A stable oxygen permeation flux of 0.48 mL cm(-2) min(-1) was obtained for a 0.3 mm thick membrane under an air/CO2 oxygen partial pressure gradient at 1000 degrees C. It was also found that 40MCO-60CPO dual phase membranes are stable for more than 60 h even when pure CO2 was used as the sweep gas, which recommends 40MCO-60CPO membranes as promising candidates for 4-end membrane operation in an oxy-fuel power plant. (c) 2012 Elsevier B.V. All rights reserved.