(JP8069808-A)      A reformer comprising reformer device for reforming hydrocarbon to generate a hydrogen rich gas comprises: (a) gas feed device for feeding CO2-contg. gas; (b) CO2 absorption device for absorbing and retaining CO2 in the CO2-contg. gas under a predetermined first condition and releasing the absorbed and retained CO2 under a redetermined second condition; (c) C)2 release device for keeping the CO2 absorption device under the predetermined second condition; and (d) replacement device for supplying the CO2 released by the CO2 release device to the reformer device to replace the hydrocarbon with the CO2. Also claimed is a fuel cell system (10) comprising a reformer (20) having reformer device (22) for reforming hydrocarbon to generate a hydrogen-rich gas, and a fuel cell (30) for consuming gaseous hydrogen fuel in the hydrogen-rich gas generated by the reformer device. The fuel cell system comprises: (i) gas feeding device for feeding a CO2 -rich gas discharged from the fuel cell; (ii) absorption device packed with CO2 absorbent for absorbing and retaining CO2 in the CO2-rich gas at a predetermined first temp. and releasing the absorbed and retained CO2 at a predetermined second temp. higher than the first temp.; (iii) heater (24) for heating the absorption device at least to the second temp. at least during non-operation state of the fuel cell to release CO2 from its absorbent; and (iv) replacement device (40) for supplying the CO2 released from the absorption device to at least one of the reformer devices to replace the hydrocarbon with the CO2 and the fuel cell to replace the hydrogen-rich gas with the CO2. Also claimed is a further fuel cell system.    USE -   The fuel cell system is applicable to various objects, e.g. fixed plants like power plants as well as moving objects like vehicles.    ADVANTAGE -   The atmos. in the reformer can be easily replaced with an inert gas. The fuel cell system including the reformer can be made more compact. The fuel cell system can absorb and retain CO2 required for replacement within the system without resupply from a gas tank.    (EP700107-B1)      A reformer comprising reformer device for reforming hydrocarbon to generate a hydrogen rich gas comprises: (a) gas feed device for feeding CO2-contg. gas; (b) CO2 absorption device for absorbing and retaining CO2 in the CO2-contg. gas under a predetermined first condition and releasing the absorbed and retained CO2 under a redetermined second condition; (c) C)2 release device for keeping the CO2 absorption device under the predetermined second condition; and (d) replacement device for supplying the CO2 released by the CO2 release device to the reformer device to replace the hydrocarbon with the CO2. Also claimed is a fuel cell system (10) comprising a reformer (20) having reformer device (22) for reforming hydrocarbon to generate a hydrogen-rich gas, and a fuel cell (30) for consuming gaseous hydrogen fuel in the hydrogen-rich gas generated by the reformer device. The fuel cell system comprises: (i) gas feeding device for feeding a CO2 -rich gas discharged from the fuel cell; (ii) absorption device packed with CO2 absorbent for absorbing and retaining CO2 in the CO2-rich gas at a predetermined first temp. and releasing the absorbed and retained CO2 at a predetermined second temp. higher than the first temp.; (iii) heater (24) for heating the absorption device at least to the second temp. at least during non-operation state of the fuel cell to release CO2 from its absorbent; and (iv) replacement device (40) for supplying the CO2 released from the absorption device to at least one of the reformer devices to replace the hydrocarbon with the CO2 and the fuel cell to replace the hydrogen-rich gas with the CO2. Also claimed is a further fuel cell system.    USE -   The fuel cell system is applicable to various objects, e.g. fixed plants like power plants as well as moving objects like vehicles.    ADVANTAGE -   The atmos. in the reformer can be easily replaced with an inert gas. The fuel cell system including the reformer can be made more compact. The fuel cell system can absorb and retain CO2 required for replacement within the system without resupply from a gas tank.