Identification of operational regions in the Chemical-Looping with Oxygen Uncoupling (CLOU) process with a Cu-based oxygen carrier

► New experimental method to determine the maximum oxygen generation rate of an oxygen carrier. ► Method to determine the minimum solids inventory that must be used in the fuel reactor. ► Three different regions were identified depending on the oxygen carrier to coal mass ratio. ► A maximum rate of oxygen generation was 2.8 × 10−3 as kg O2/s per kg of OC at 980 °C. ► From this value the estimated solids inventory in the fuel reactor was 29 kg/MWth.