Calcium oxide/carbon dioxide reactivity in a packed bed reactor of a chemical heat pump for high-temperature gas reactors

The thermal performance of a chemical heat pump that uses a calcium oxide/c arbon dioxide reaction system was discussed as a heat storage system for ut ilizing heat output from high temperature gas reactors (HTGR). Calcium oxid e/carbon dioxide reactivity for the heat pump was measured using a packed b ed reactor containing 1.0 kg of reactant. The reactor was capable of storin g heat at 900 degreesC by decarbonation of calcium carbonate and generating up to 997 degreesC by carbonation of calcium oxide. The amount of stored h eat in the reactor was 800-900 kJ kg(-1). The output temperature of the rea ctor could be controlled by regulating the carbonation pressure. The therma l storage performance of the reactor was superior to that of conventional s ensible heat storage systems. A heat pump using this CaO/CO2 reactor is exp ected to contribute to thermal load leveling and to realize highly efficien t utilization of HTGR output due to the high heat storage density and high- quality temperature output of the heat pump. (C) 2001 Elsevier Science B.V. All rights reserved.