Thermal management for chemical looping systems with chemical production

•A thermal management method is firstly reported to achieve an autothermal operation.•A new CLAS system using dual fast fluidized bed reactors is designed and modeled.•Heat integration can realize a maximum 62.37% decrement of external energy demand.•Heat transfer between hot and cold streams leads to the main energy-cost penalty.•The unit exergy cost for oxygen production can achieve a minimum 32.99% decrement.