Evaluation of the Redox Performance and Characterization of Fe₂O₃/CeO₂/ZrO₂ Oxygen Carriers under High Temperature in Situ Gasification Chemical-Looping Combustion Conditions

Journal Article · Wed Dec 04 00:00:00 EST 2019 · Energy and Fuels

DOI:https://doi.org/10.1021/acs.energyfuels.9b03018· OSTI ID:1635625

Means, Nicholas C.  ^[1]; Hammache, Sonia ^[1]; Burgess, Ward A.  ^[1]; Howard, Bret H. ^[2]; Smith, Mark W. ^[3]

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1. National Energy Technology Laboratory (NETL), Pittsburgh, PA (United States); Leidos Research Support Team, Pittsburgh, PA (United States)
2. National Energy Technology Laboratory (NETL), Pittsburgh, PA (United States)
3. National Energy Technology Laboratory (NETL), Morgantown, WV (United States)

Iron-based oxygen carriers with a CeO₂ support have interesting redox applications in chemical-looping combustion (CLC). CeO₂ behaves as an active support for many oxygen carrier applications because of the reversible release of lattice oxygen. High temperature processes may lead to improved process efficiency; however, the poor thermal stability of CeO₂ gives rise to a need for oxygen carriers that can resist sintering and agglomeration and maintain reactivity after multiple reduction and oxidation (redox) cycles during in situ gasification chemical-looping combustion (iG-CLC) at 1100 °C. In this work, Fe-based oxygen carriers on CeO₂, ZrO₂, and Ce_0.75Zr_0.25O₂ supports were prepared by a coprecipitation method. The redox stability, reactivity, and sintering of the oxygen carriers were evaluated to investigate the effect of the CeO₂–ZrO₂ solid solution support. The oxygen transport capability was evaluated in a drop tube fixed-bed reactor under iG-CLC conditions with coal char at 1100 °C for 10 redox cycles. The CeO₂–ZrO₂ solid solution improved the oxygen mobility of the support from the creation of more oxygen defects. The Fe–Ce oxygen carrier had the highest oxygen transport capability because of the formation of cerium orthoferrite (CeFeO₃) during high temperature reduction. The Fe–Ce–Zr oxygen carrier showed improved reactivity over the Fe–Ce oxygen carrier as the number of redox cycles increased. The oxygen carriers, before and after multiple redox cycles, were characterized by X-ray diffraction, scanning electron microscopy, and surface/pore analysis.

• Research Organization: National Energy Technology Laboratory (NETL), Pittsburgh, PA, Morgantown, WV, and Albany, OR (United States)
• Sponsoring Organization: USDOE Office of Fossil Energy (FE)
• Grant/Contract Number: 89243318CFE000003
• OSTI ID: 1635625
• Journal Information: Energy and Fuels, Vol. 34, Issue 1; ISSN 0887-0624
• Publisher: American Chemical Society (ACS)
• Country of Publication: United States
• Language: English

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37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY