著者

Keita Tanahashi Yusei Omura Hidekazu Naya Yuji Kunisada Norihito Sakaguchi Ade Kurniawan Takahiro Nomura

出版者

The Iron and Steel Institute of Japan

雑誌

ISIJ International (ISSN:09151559)

巻号頁・発行日

vol.62, no.12, pp.2578-2586, 2022-12-15 (Released:2022-12-15)

参考文献数

30

被引用文献数

1

---

High-temperature pressure swing adsorption (HT-PSA) is a promising energy-saving approach for oxygen production from air. Ca2AlMnO5+δ, 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+δ by pressure–composition–temperature (PCT) measurements and investigated the HT-PSA performance of Ca2AlMnO5+δ pellets in a 100 g-scale packed-bed-type reactor. PCT measurements revealed that Ca2AlMnO5+δ can reversibly separate 2.2 wt% of oxygen per cycle under equilibrium conditions between ambient oxygen partial pressure and 5×10−4 MPa at 525°C. However, in a 5 min switching HT-PSA test, Ca2AlMnO5+δ 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+δ. 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.