Effects of Oxygen Vacancy Order-Disorder Phase Transition on Air Separation by Perovskite Sorbents

Han Chun Wu, Jerry Lin

Research output: Contribution to journalArticle

9 Scopus citations

Abstract

Perovskite oxide sorbents offer promise for adsorption-based separation of air to produce an oxygen enriched stream. The oxygen desorption rate however should be further improved. This work studies the oxygen sorption properties of three La1-xSrxCo1-yFeyO3-δ (LSCF) perovskite oxides with and without oxygen vacancy disorder-order phase transition. The LSCF with lower iron content [La0.1Sr0.9Co0.9Fe0.1O3-δ (LSCF1991)] shows the highest sorption capacity in 500-800 °C. The material with disorder-order phase transition during desorption also exhibits enhanced oxygen desorption rate during the TGA measurement. However, in the fixed-bed desorption process, no obvious rate enhancement resulting from the disorder-order phase transition in oxygen desorption is observed for the LSCF1991 sorbent. The LSCF1991 sample in the fixed-bed quenched at 600 °C after 2 h of desorption shows occurrence of disorder-order phase transition for the perovskite sorbent in the fixed-bed environment. The difference in oxygen desorption rate observed between the fixed-bed process and the TGA experiment is due to much higher oxygen partial pressure in the gas surrounding the sorbent during the fixed-bed oxygen desorption process under which the disorder-order phase transition does not occur until the late stage of oxygen desorption.

Original languageEnglish (US)
Pages (from-to)6057-6064
Number of pages8
JournalIndustrial and Engineering Chemistry Research
Volume56
Issue number20
DOIs
StatePublished - May 24 2017

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ASJC Scopus subject areas

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

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