Oxygen absorption and desorption properties of YBaCo4O7+δ monolithic oxygen carrier in the fixed-bed reactor

The technology of chemical looping air separation, with the characteristics of simple operation, low cost, and low energy consumption, separates oxygen from air with the oxygen carrier. In this work, reaction properties of monolithic oxygen carriers were investigated in a fixed-bed apparatus, with the consideration of the reactor temperature, oxygen concentration, and reaction gas flow. The XRD results showed that active phase, Al2O3, and cordierite cannot react with each other in calcination processing. The SEM results showed that the micromorphology of oxygen carrier was loaded on cordierite honeycomb uniformly with sphere or sphere-like particles. Oxygen carriers show a faster oxygen release rate and a slower oxygen intake rate. With increasing of absorption temperature, oxygen concentration of inlet gas, and desorption temperature, the reaction rate per unit mass increases. With increasing of gas flow rate, the reaction rate per unit mass decreases. The maximum value of the reaction rate per unit mass was obtained by Y0.95Ti0.05BaCo4O7+delta monolith sample. Samples substituted with Dy element showed fine performance of stability, as Dy substitution causes more serious local lattice distortions.

Automated summary

This study investigates the reaction properties of monolithic oxygen carriers in a fixed-bed apparatus and explores the effects of reaction temperature, oxygen concentration, and gas flow rate on the reaction performance. The experimental results show that the oxygen carriers exhibit a uniform morphology and a fast oxygen release rate. Further analysis reveals that increasing the absorption temperature, the oxygen concentration of the inlet gas, and the desorption temperature enhances the reaction rate per unit mass, while increasing the gas flow rate reduces the reaction rate per unit mass. Samples doped with Dy element demonstrate good stability.