Performance and Kinetic Evaluation of Synthesized CuO/SBA-15 Oxygen Carrier for Chemical Looping with Oxygen Uncoupling

Chemical looping oxygen uncoupling (CLOU), a variant of chemical looping combustion (CLC), is one of the most promising combustion technologies for inherent separation and feasible capture of carbon dioxide. Herein, synthesized SBA-15, a highly ordered mesoporous silica support, is used to host CuO for developing a new variant of an oxygen-carrier material. Based on thermoanalytical evaluations, a typical CuO/SBA-15 composition with 36 mass% CuO loading is identified as highly suitable with an average oxygen transport capacity of 3.61%. In addition, extensive studies along with model-dependent kinetic evaluations are carried out using isothermal thermogravimetric data for the reduction-reoxidation of CuO/SBA-15. It is observed that the Avrami-Erofeev random nucleation and subsequence growth model (A2) fitted well for the reduction reaction, while the 3D diffusion model (D3) described suitably the reoxidation reaction in the temperature range of 800-950 degrees C. Reduction-reoxidation rate data and kinetic information derived from corresponding isothermal conversion curves can contribute immensely to design and establish operational strategies for interconnected CLOU reactors.