A fluidized bed reactor system for introducing heat energy into or removing heat energy from fluidized reactants undergoing reaction includes, in a first embodiment, a fluidized bed reactor for fluidizing a particulate material in a fluidizing medium and a heat generator for supplying heat energy to the fluidized bed. A plurality of heat pipes interconnect the heat generator and the fluidized bed reactor with the evaporator portions of the heat pipes extending into the heat generator and the condenser portions thereof extending into the fluidized bed. Thermal energy from the heat generator is absorbed by the evaporator portions of the heat pipes and conveyed through the heat pipes to the condenser portions where the thermal energy is transferred to the fluidized bed. Since heat pipes transfer thermal energy at a relatively constant temperature throughout a wide range of thermal flows, heat energy can be introduced into endothermic fluidized reactions at a relatively constant temperature to achieve preferred reaction rates. In a second embodiment, the evaporator portion of the heat pipes extend into the fluidized bed and the condenser portions extend outwardly of the fluidized bed to a heat sink.
