Experimental Investigation of the Effects of Fluidizing Gas on Copper-Manganese Mixed Oxide?s Reactivity for Chemical LoopingCombustion of CH4

The purpose of this study is to investigate how CO2as afluidizing agent affects the reactivity of a Cu-Mn mixed oxideas an oxygen carrier for chemical looping combustion (CLC) ofCH4. The length of the reduction period of the oxygen carrier wasfound to be an important parameter while determining the effect ofCO2. If the reduction period is short, which occurs in chemicallooping combustion with oxygen uncoupling, no significant effectwas observed. However, if the oxygen carrier is exposed for alonger reduction period (characteristic of CLC) to partially or fullyreduce it to Cu and MnO phases, these reduced phases catalyzeCH4dry reforming and reverse water-gas shift reactions.Consequently, a significant amount of CO and comparativelysmall amount of H2are produced. These side reactions should beavoided to achieve complete CH4combustion to CO2by adjusting the residence time of the oxygen carrier particles in the fuelreactor.