Regeneration mechanism of CuO-CaSO4 based oxygen carriers

• Published in: Fuel (Guildford) Vol. 306; p. 121668
• Main Authors: Yang, Jie, Liu, Shengyu, Dai, Quxiu, Guo, Zhiying, Ao, Ran, Pan, Jinghuan, Yang, Yingchun, Yang, Yijin, Ma, Liping
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 15.12.2021; Elsevier BV
• Subjects: Copper oxides; Copper sulfides; CuO-CaSO4 based oxygen carriers; High temperature; Industrial applications; Kinetic analysis; Oxidation; Oxygen; Regeneration; Regeneration mechanism; Thermodynamic analysis; Regeneration mechanism; Thermodynamic analysis; Kinetic analysis; CuO-CaSO4 based oxygen carriers
• ISSN: 0016-2361; 1873-7153
• DOI: 10.1016/j.fuel.2021.121668

•Regeneration performance of CuO-CaSO4 oxygen carrier has been investigated.•Thermodynamics of CuO-CaSO4 regeneration has been investigated by FactSage.•Kinetic analysis of CuO-CaSO4 regeneration has been researched by isoconversional methods.•Regeneration mechanism of CuO-CaSO4 has been analyzed. CuO-CaSO4 based materials are widely used in chemical looping technology. Although the reduction process is essential, the regeneration process of the oxygen carrier is also vital. The regeneration capacity determines the lifetime of the oxygen carrier. The exploration of the regeneration mechanism of oxygen carriers is an indispensable part of its applicability in industry. Recently, just a few reports were dealing with the regeneration of CuO-CaSO4 oxygen carriers. In the present work, the regeneration mechanism of the CuO-CaSO4 oxygen carriers was analyzed by thermodynamic, and kinetic analysis. It was observed that the high temperature is not beneficial to the occurrence of these reactions at 923 K. The CuO-CaSO4 oxygen carrier could be regenerated entirely. The regeneration process was described in two steps, with the 3D symmetry diffusion module. The first step was when CaS, Cu2S, Cu reacts with oxygen to produce CaSO4, Cu2O, CuSO4, and some CuO. The second step is the oxidation of Cu2O to generate CuO. After analysis, the regeneration kinetic function of the oxygen carrier compound of CuO-CaSO4 has been achieved. This work indicates that the CuO-CaSO4 based oxygen carrier is a recommended oxygen carrier in the chemical looping process, which lays a foundation for the practical industrial application of the oxygen carriers.