To provide a device and system for regeneratively separating carbon dioxide which can surely separate carbon dioxide with an extremely higher efficiency than the conventional device and system with a simple constitution.

When high-temperature sections and low-temperature sections are provided around a rotor, the carbon dioxide contained in an exhaust gas can be absorbed and separated easily from the exhaust gas by only rotating the rotor. Therefore, a highly reliable absorbing and separating system which can be simplified extremely in constitution, can be maintained easily, and can be reduced in regenerating cost can be realized. In addition, when lithium zirconate, an alkaline metal oxide, and/or an alkaline earth oxide are used, the system becomes chemically and mechanically stable and can reversibly and stably cause the absorption and discharge of carbon dioxide.