Application of CoFe2O4-NiO nanoparticle-coated foam-structured material in a high-flux solar thermochemical reactor

• Published in: Science China. Technological sciences Vol. 66; no. 11; pp. 3276 - 3286
• Main Authors: Zhang, Hao, Zhang, XiaoMi, Yang, DaZhi, Shuai, Yong, Guene Lougou, Bachirou, Pan, QingHui, Wang, FuQiang
• Format: Journal Article
• Language: English
• Published: Beijing Science China Press 01.11.2023; Springer Nature B.V
• Subjects: Carbon dioxide; Cobalt ferrites; Design optimization; Energy conversion efficiency; Energy recovery; Engineering; Fuel production; Fuels; Heat loss; High temperature; Nanoparticles; Nickel oxides; Oxidation; Oxygen; Reactor design; Thermodynamic efficiency; Thermogravimetry; splitting; solar thermochemistry; CO; reactor design; iron-base oxygen carrier; two-step redox cycle
• ISSN: 1674-7321; 1869-1900
• DOI: 10.1007/s11431-023-2397-7

The splitting of carbon dioxide through the two-step solar thermochemical cycle presents enormous potential, for it holds the dual functionalities of solar fuel production and carbon-based energy recovery. However, the industrialization of this technology is impeded by two critical factors: The absence of fully developed oxygen carriers and advanced reaction devices that deliver exceptional performance. In order to identify a potentially effective oxygen carrier, 50 wt% NiO-modified CoFe 2 O 4 is selected as the active component and characterized by means of thermogravimetry, scanning electron microscopy, and energy dispersive spectroscopy, so as to clarify its oxygen exchange capacity, micromorphology and elemental composition in high-temperature thermochemical cycles. Further, nanoparticle-coated foam-structured materials are prepared in combination with SiC ceramic foam for experimental testing in a high-flux solar reactor. The results indicate that a peak CO yield of 1.96 mL min −1 g −1 can be gained in a 1500–1250 K preliminary test, demonstrating the application potential of the material. In contrast to conventional redox materials, the CO 2 activity of the materials synthesized in this study exhibits an enhancement with rising oxidation temperature. It means that isothermal cycles can potentially achieve higher conversion and fuel yield than non-isothermal cycles, while simultaneously reducing the amount of irreversible heat loss during high-temperature cycling. Although the estimated steady-state thermal efficiency of the solar reactor can reach up to 42%, further optimization of the reactor design is necessary to enhance energy conversion efficiency, as it is partially limited by the dimensions of the reaction chamber.