Fixed-bed performance for production of oxygen enriched carbon dioxide stream by perovskite-type ceramic sorbent

This paper reports on an experimental study on production of oxygen-enriched carbon dioxide stream by a fixed-bed packed with a perovskite-type ceramic sorbent La_0.1Sr_0.9Co _0.5Fe_0.5O_3-δ, which can adsorb oxygen from air. Oxygen-enriched carbon dioxide stream is produced by passing carbon dioxide into the fixed-bed saturated with oxygen. Fixed-bed experiments were performed to study the oxygen separation performance of this sorbent. The separation process was experimentally confirmed to be a reversible chemical sorption and desorption process. Experimental results are also reported to show the effects of operation conditions, including adsorption time, flow rates of feed gases, and fixed-bed temperatures in the adsorption and desorption steps, on average oxygen concentration of the product stream, oxygen recovery, carbon dioxide recovery and productivity. Experimental results suggest that adsorption and desorption temperatures are the most critical operation parameters. Under the optimum conditions (850 and 900°C adsorption and desorption temperatures) the fixed-bed adsorber can produce an oxygen-enriched carbon dioxide stream with average oxygen concentration, oxygen recovery, carbon dioxide recovery and productivity, respectively, of 58.8%, 18.7%, 26.6% and 0.272 ml/min. This oxygen-enriched carbon dioxide stream may be used as an oxidant in the oxyfuel combustion process.