Influences of reaction and thermal conditions on microstructural evolutions of ilmenite oxygen carriers for chemical looping combustion

Liangyong Chen, Guoqiang Wei, Kunlei Liu

Research output: Contribution to journalArticlepeer-review

6 Scopus citations

Abstract

Ilmenite ore has been widely accepted to be a cost-effective oxygen carrier (OC) of Chemical Looping Combustion (CLC) for CO2 capture. The focus of this study is to investigate into the influences of chemical impact, thermal variation and ageing effect on microstructure and performance evolutions of ilmenite OCs. Iron element migration, crystallinity and morphology alterations, and irreversible change of chemical composition were identified to be the major aspects responsible for gradual microstructural evolutions of Ilmenite OCs. Iron element migration from bulk materials to particle surface, occurring during the oxidation step of redox cycles, was of temperature- and O2 concentration- dependences. A schematic diagram was developed to explain the pathways of irreversible iron migration and alteration of chemical composition in redox cycle reactions. By lowering phase interaction between Fe2TiO5 and TiO2, the cycled thermal shock (due to reaction and processing in CLC) promotes the iron element concentration on OC particle surface and the ilmenite OC reactivity. Long-term ageing at elevated temperature, as one of typical severe conditions in CLC, exhibits activation effects for ilmenite OCs, even though it causes increased crystallinity, denser particle structure and redistribution of Fe2TiO5-TiO2 phase

Original languageEnglish
Article number107139
JournalFuel Processing Technology
Volume228
DOIs
StatePublished - Apr 2022

Bibliographical note

Funding Information:
This research was supported by National Key R&D Program of China (No. 2018YFB0605401-04 ), “Entrepreneurship & Innovation Plan” of Jiangsu Province of China (2018), and Collaborative Research Projects between Southeast University and China Pharmaceutical University (No. 2242019K3DZ08 ). The authors gratefully acknowledge Prof. Zhenshan Li at Tsinghua University, who provided ilmenite ore for this investigation.

Funding Information:
This research was supported by National Key R&D Program of China (No. 2018YFB0605401-04), ?Entrepreneurship & Innovation Plan? of Jiangsu Province of China (2018), and Collaborative Research Projects between Southeast University and China Pharmaceutical University (No. 2242019K3DZ08). The authors gratefully acknowledge Prof. Zhenshan Li at Tsinghua University, who provided ilmenite ore for this investigation.

Publisher Copyright:
© 2021

Keywords

  • Chemical-Looping Combustion
  • Ilmenite oxygen carriers
  • Microstructural evolution
  • Redox cycle
  • Thermal conditions

ASJC Scopus subject areas

  • Chemical Engineering (all)
  • Fuel Technology
  • Energy Engineering and Power Technology

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