New Triclinic Perovskite-Type Oxide Ba₅CaFe₄O₁₂ for Low-Temperature Operated Chemical Looping Air Separation.

Area of Science:

• Materials Science
• Chemical Engineering
• Inorganic Chemistry

Background:

• Oxygen storage materials (OSMs) are crucial for chemical looping technologies.
• Chemical looping air separation (CLAS) offers a promising route for industrial oxygen production.
• Developing energy-efficient OSMs for low-temperature CLAS remains a significant challenge.

Purpose of the Study:

• To discover and characterize a new iron-based oxide with enhanced oxygen storage capabilities.
• To evaluate the potential of this new material for low-temperature chemical looping air separation.
• To compare its performance against existing OSMs for oxygen production efficiency.

Main Methods:

• Synthesis and structural characterization of Ba5CaFe4O12.
• Evaluation of oxygen intake and release properties below 400 °C.
• Performance assessment for theoretical daily oxygen production rate.

Main Results:

• Discovery of Ba5CaFe4O12, a cost-competitive material with a unique 5-fold perovskite-type structure.
• Demonstrated excellent oxygen storage and release properties below 400 °C.
• Achieved a theoretical daily oxygen production rate of 2.41 m3 O2 kg-1 OSM at 370 °C, significantly outperforming Sr0.76Ca0.24FeO3-δ.

Conclusions:

• Ba5CaFe4O12 is a highly effective low-temperature oxygen storage material.
• Its unique structure facilitates efficient oxygen exchange at temperatures relevant for energy-saving CLAS.
• This discovery paves the way for cost reduction and improved energy efficiency in industrial oxygen production via CLAS.