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https://hdl.handle.net/2115/88584

Oxygen Separation Performance of Ca2AlMnO5+delta as an Oxygen Storage Material for High-Temperature Pressure Swing Adsorption

英語

packed bed

2022-12-15

一般社団法人 日本鉄鋼協会 (The Iron and Steel Institute of Japan)

ISIJ international

62(12)

2578-2586

High-temperature pressure swing adsorption (HT-PSA) is a promising energy-saving approach for oxygen production from air. Ca2AlMnO5+delta, a Brownmillerite-type perovskite, is a promising sorbent for HT-PSA because of its remarkably high oxygen storage capacity (up to 3.3 wt%). In this study, we investigated the redox thermodynamics of Ca2AlMnO5+delta by pressure-composition-temperature (PCT) measurements and investigated the HT-PSA performance of Ca2AlMnO5+delta pellets in a 100 g-scale packed-bed-type reactor. PCT measurements revealed that Ca2AlMnO5+delta can reversibly separate 2.2 wt% of oxygen per cycle under equilibrium conditions between ambient oxygen partial pressure and 5x10-4 MPa at 525 degrees C. However, in a 5 min switching HT-PSA test, Ca2AlMnO5+delta pellets were able to reversibly separate less than 1 wt% oxygen per cycle, which is significantly lower than that estimated from the thermodynamic properties of Ca2AlMnO5+delta. On the other hand, the exothermic oxygen storage and endothermic oxygen release reactions cause significant temperature variation of the packed bed. This study clarifies that, in order to increase the energy efficiency of oxygen separation by HT-PSA, there is a need to compensate for the heat of reaction, which changes the reactor temperature in a direction that interferes with the reaction.

学術雑誌論文

Version of Record

0915-1559