Chemical looping with oxygen uncoupling (CLOU) is the tendency of releasing gaseous oxygen of an oxygen carrier upon heating, which is the key property for the efficient and cleaner combustion of solid fuels for their wide exploitation for thermal power applications. The solvent-free, improved synthesis method was developed for the synthesis of pure bixbyite, FeMnO3 (Ia3-, a=b=c=0.94 nm) as a low-cost, oxygen carrier by exposing of the abundantly available precursors (Fe3O4 and MnO) under inert- or reduction- atmosphere followed by air at 900°C. The bixbyite FeMnO3 showed the enhanced, stable multi-cycle CLOU performance than that of the physical mixture and it is converted into FeMn2O4 after the complete exhaustion of reactive oxygen under CLOU conditions. FeMnO3 showed the uniform elemental distribution of Fe, Mn and O, which facilitate the regeneration in air upon heating for multi-cycle performance. 3.2 wt.% of reactive oxygen can be obtained compared to the mass of FeMnO3 which is almost equal to the theoretical value under CLOU conditions. The lattice of FeMnO3 is altered linearly above 100°C with the increase of temperature, however; without the decomposition of the bixbyite phase and it was reinstated virtually upon cooling in air.
All Science Journal Classification (ASJC) codes
- General Chemistry
- General Chemical Engineering