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Novel Bimetallic Oxygen Carriers for Use in Chemical Looping Combustion

National Energy Technology Laboratory

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Technology Marketing Summary

Research is currently active on the patent pending technology titled, "Metal Ferrite Oxygen Carriers for Chemical Looping Combustion of Solid Fuels." This technology is available for licensing and/or further collaborative research from the U.S. Department of Energy’s National Energy Technology Laboratory.


Chemical looping combustion (CLC) is a promising technology for coal-derived energy production. CLC offers a major advantage over conventional coal combustion by directly producing  a concentrated stream of CO2 without expending the significant energy required for CO2 separation. The development of robust oxygen carriers is critical for the efficient operation and adoption of CLC technology.

Traditional oxygen carriers such as CuO, Fe2O3, NiO, and CoO have disadvantages including low reactivity (Fe2O3), low melting point and high agglomeration (CuO), and health and environmental concerns (NiO). The development of new oxygen carriers with enhanced performance characteristics is required for successful deployment of coal CLC processes.

This invention describes the use of novel bimetallic oxygen carriers consisting of group II metal ferrites (MgFe2O4, CaFe2O4, SrFe2O4, and BaFe2O4) and transition metal ferrites (MnFeO3 and CoFe2O4) for CLC of solid fuels such as coal, pet coke, and biomass. All the metal ferrites demonstrated better performance for coal CLC when compared to Fe2O3, including high and stable reactivity over multiple reduction/oxidation cycles as well as high attrition resistance. Further, the ferrite-based oxygen carriers displayed a low tendency to agglomerate at high temperatures. The metal ferrites can be produced using readily available materials at a cost comparable to Fe2O3 oxygen carriers.

  • Improved reduction/oxidation rates compared to Fe2O3
  • Stable at high temperatures and over multiple oxidation-reduction cycles
  • Metal ferrites can be produced using readily available materials at comparable cost to standard oxygen carriers
  • Carriers are environmentally benign
Applications and Industries
  • Chemical looping combustion of coal
  • Chemical looping gasification of coal to produce synthesis gas
  • Combustion/gasification processes using biomass, pet coke, and other solid fuels
More Information

U.S. Patent No. 9,557,053, titled "Metal Ferrite Oxygen Carriers for Chemical Looping Combustion of Solid Fuels" issued January 31, 2017.

Inventors: Ranjani V. Siriwardane and Yueying Fan

U.S. Non-Provisional Application No. 14/870,051, titled "Metal Ferrite Oxygen Carriers for Gasification of Solid Carbonaceous Fuel" filed on September 30, 2015.

Inventors: Ranjani V. Siriwardane and Yueying Fan

Patents and Patent Applications
ID Number
Title and Abstract
Primary Lab
Patent 9,557,053
Metal ferrite oxygen carriers for chemical looping combustion of solid fuels
The disclosure provides a metal ferrite oxygen carrier for the chemical looping combustion of solid carbonaceous fuels, such as coal, coke, coal and biomass char, and the like. The metal ferrite oxygen carrier comprises MFe.sub.xO.sub.y on an inert support, where MFe.sub.xO.sub.y is a chemical composition and M is one of Mg, Ca, Sr, Ba, Co, Mn, and combinations thereof. For example, MFe.sub.xO.sub.y may be one of MgFe.sub.2O.sub.4, CaFe.sub.2O.sub.4, SrFe.sub.2O.sub.4, BaFe.sub.2O.sub.4, CoFe.sub.2O.sub.4, MnFeO.sub.3, and combinations thereof. The MFe.sub.xO.sub.y is supported on an inert support. The inert support disperses the MFe.sub.xO.sub.y oxides to avoid agglomeration and improve performance stability. In an embodiment, the inert support comprises from about 5 wt. % to about 60 wt. % of the metal ferrite oxygen carrier and the MFe.sub.xO.sub.y comprises at least 30 wt. % of the metal ferrite oxygen carrier. The metal ferrite oxygen carriers disclosed display improved reduction rates over Fe.sub.2O.sub.3, and improved oxidation rates over CuO.
National Energy Technology Laboratory 01/31/2017
Technology Status
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