Cyclic reactivity of the sol–gel and graphite impregnation-derived Cu-based oxygen carriers for chemical looping with oxygen uncoupling

• Published in: Journal of thermal analysis and calorimetry 2021-11, Vol.146 (4), p.1833-1843
• Main Authors: Cao, Yang, He, Boshu, Yan, Linbo
• Format: Article
• Language: English
• Subjects: Analytical Chemistry; Chemistry; Chemistry and Materials Science; Control engineering; Copper oxides; Fluidized bed combustion; Fuel combustion; Gasification; Graphite; Growth models; High temperature; Impregnation; Inorganic Chemistry; Measurement Science and Instrumentation; Nucleation; Oxy-fuel; Oxygen; Physical Chemistry; Polymer Sciences; Reactivity; Reduction; Sol-gel processes; Stability analysis; Yttrium oxide; Zirconium dioxide
• ISSN: 1388-6150; 1588-2926
• DOI: 10.1007/s10973-020-10163-6

Chemical looping with oxygen uncoupling (CLOU) is a promising technology to be used in combination with the oxy-fuel combustion/gasification processes for carbon capture and sequestration in that it reduces the energy penalty for O 2 generation; hence, much attention has been focused on the production of proper oxygen carriers. In this work, four oxygen carrier candidates for CLOU made of 90% CuO and 10% ZrO 2 or Y 2 O 3 are first prepared with the sol–gel and graphite impregnation methods. The reduction reactivity of the prepared oxygen carriers is investigated at 900, 950, and 1000 °C in the CO 2 atmosphere, and the redox stability is evaluated through ten sequential cycles using the thermogravimetric analyzer. It is found that the Avrami–Erofeev random nucleation and subsequence growth model (A2) describes the reduction process very well. CuO/ZrO 2 prepared by the graphite impregnation performs better reactivity and stability than the others. The agglomeration and sintering of the oxygen carriers at high temperatures are found to be the main cause of the low reactivity over the repeated cycles.