High temperature sorption separation of air for producing oxygen-enriched CO2 stream

Authors

  • Qing Yang,

    1. Dept. of Chemical and Materials Engineering, University of Cincinnati, Cincinnati, OH 45221
    2. Dept. of Chemical and Materials Engineering, Arizona State University, Tempe, AZ 85287
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  • Y. S. Lin,

    Corresponding author
    1. Dept. of Chemical and Materials Engineering, University of Cincinnati, Cincinnati, OH 45221
    2. Dept. of Chemical and Materials Engineering, Arizona State University, Tempe, AZ 85287
    • Dept. of Chemical and Materials Engineering, Arizona State University, Tempe, AZ 85287
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  • Martin Bülow

    1. The BOC Group, PGS Technology, 100 Mountain Avenue, Murray Hill, NJ 07974
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Abstract

A new high temperature sorption process for production of oxygen-enriched carbon dioxide stream through air separation with carbon dioxide as the purge gas is reported. The process is based on a fixed-bed packed with a perovskite-type strontium-iron doped lanthanum cobaltite, as the sorbent, operated in 500–900°C. Oxygen is adsorbed by the perovskite-type sorbent with air being fed. An oxygen-enriched carbon dioxide stream is obtained when the fixed-bed is regenerated with carbon dioxide as the desorption gas. A specific carbonation-reaction mechanism for the O2-desorption process and a complete reverse reaction during the O2-sorption process are identified with the evidences of XRD and TGA analysis. A study of the sorption process kinetics over a temperature range of 600–800°C was conducted by fixed-bed sorption/desorption and TGA experiments. Both desorption and sorption processes exhibit a high reaction rate in an initial stage followed by a slower rate in a second stage. A remarkable separation efficiency was observed at 800°C. The new process offers potential for applications in a number of processes including in the efficient and environmentally benign oxyfuel coal combustion process for power generation. © 2005 American Institute of Chemical Engineers AIChE J, 2006

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