出版社：Chinese Association for Aerosol Research in Taiwan
摘要：Chemical looping air separation (CLAS) is a novel and efficient method of producing high-purity oxygen because of its low-energy demands. Cu-based materials are suitable oxygen carriers (OCs) for CLAS. In the current study, Cu-based OCs in different particle sizes were prepared using various methods (viz., through mechanical mixing, impregnation, and coprecipitation) and different supporting materials (viz., ZrO2, SiO2, and Al2O3) and porosities (viz., in the mesopore range). This study evaluated the reactivity, reaction kinetics, and recyclability of these OCs by measuring their conversion rates for reduction (oxygen release) and oxidation (regeneration) in a thermogravimetric analyzer. CuO OCs on ZrO2 nanoparticles prepared through impregnation (CuZr-IM) exhibited almost complete conversion and the fastest reaction rates of all the OCs for reduction and oxidation. These characteristics are primarily attributable to the fine particles (100–250 nm) of the OCs. Furthermore, the CuO on the surface of the ZrO2 particles was distributed in a uniform pattern, as these fine particles displayed greater oxygen mobility and more rapid diffusion than the micrometer-sized particles paired with bulk materials. Kinetic analysis revealed that Avrami-Erofe’ev random nucleation and the subsequent growth reaction model with n = 2 (A2), with an observed activation energy of 140.2 kJ mol–1 in our study, is the optimal fitting for CuZr-IM OC conversion during reduction, and a long-term-stability test indicated that this OC is an appropriate candidate for CLAS.
