Ni promoted Fe-CaO dual functional materials for calcium chemical dual looping

Shuzhuang Sun, Su He, Chunfei Wu*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)

Abstract

Reverse water–gas shift reaction using renewable H2 is a promising route for CO2 upgrade, however, it is restricted by the equilibrium. The chemical looping reverse water–gas shift reaction using oxygen carriers (i.e. Fe) has proven a more effective CO2 utilization process to produce CO. However, CO2 with high purity is needed to obtain concentrated CO. Herein, we propose a calcium chemical dual looping using one-pot sol–gel synthesized Ca-Fe dual functional materials (DFMs). The CO2 in the exhaust gas (∼10% CO2) can be captured and transformed into carbonates and then in-situ converted into CO through continuous chemical looping in H2 atmosphere. This process avoids CO2 enrichment, storage and transportation and simultaneously realizes efficient CO2 conversion. The Ca-Fe DFMs possessed significantly improved catalytic efficiency (enhanced real-time CO generation rate) compared to CaO. It is found that Ni1Fe9-CaO could optimally achieve 11.3 mmol gDFM−1 CO yield, 82.5% CO2 conversion and 99.9% CO selectivity at 650 °C. Notably, Ni1Fe9-CaO displayed high CO2 conversion (>80%) and CO selectivity (>99.9%) during the cycle tests and possessed enhanced stability in relation to CO yield after 10 cycles (20.9% and 35.5% decrease for Ni1Fe9-CaO and CaO, respectively). Herein, Ca2Fe2O5 plays two roles: acting as an oxygen carrier for in-situ chemical looping to produce CO and a thermally stable physical barrier to retard the sintering of CaO. It is noted that Fe-related species could be reduced into the metallic state at the end of hydrogenation, resulting in CO formation in the following CO2 capture process.

Original languageEnglish
Article number135752
JournalChemical Engineering Journal
Volume441
Early online date28 Mar 2022
DOIs
Publication statusPublished - 01 Aug 2022

Bibliographical note

Funding Information:
The authors gratefully acknowledge financial support from the China Scholarship Council (reference number:201906450023). This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 823745.

Funding Information:
The authors gratefully acknowledge financial support from the China Scholarship Council (reference number:201906450023). This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 823745.

Publisher Copyright:
© 2022 Elsevier B.V.

Keywords

  • Calcium looping
  • Chemical looping
  • Dual functional materials

ASJC Scopus subject areas

  • Chemistry(all)
  • Environmental Chemistry
  • Chemical Engineering(all)
  • Industrial and Manufacturing Engineering

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