Characterization of natural copper ore in anthracite fueled Chemical-Looping with Oxygen Uncoupling (CLOU)

Chemical Looping with Oxygen Uncoupling (CLOU) is an advanced approach proposed for improving the utilization degree of solid fuels and speeding up the reaction rate in Chemical-Looping Combustion technology (CLC). In CLOU system, OC circulates between fuel reactor (FR) and air reactor (AR), providing gaseous oxygen for the combustion of fuels (in FR) and then being regenerated by absorbing gaseous oxygen from air (in AR). In such a way, continuous oxygen stream can be gained, which creates steady combustion atmosphere in the FR, leading to very pure CO2 stream in the exit of FR. Because of the fuels combust directly with gaseous oxygen in the FR, the reaction rate and the utilization of fuels can be improved in CLOU compared with normal CLC. Recently, many synthetic OCs were developed for CLOU, as summarized by Adánez et al. [1]. These OCs exhibited excellent characteristics in the CLOU process. High conversion of solid fuels and high combustion efficiency were attainted in these published works. The OCs in the related literatures has high purity; however the cost of these OCs is high, which must be lowered before using in the future industrial CLOU systems. Therefore, an OC with low price has to be found. Natural copper ore is a good choice for large-scaled CLOU system because of its low cost and abundant storage. Before this work, copper ore has been considered by Wen et al [2] with respect to oxygen release/uptake characteristics. The copper ore tested in their work exhibits good performance in multiple redoxs, generating continuous oxygen-contained atmosphere. The thermochemical characterization of copper ore in CLOU, however, is still limited in this time. In this paper, a type of natural copper ore in China was utilized as OC in the CLOU of anthracite. Simulated CLOU process in a fluidized bed was investigated to study the reactivity of the natural ore and explore different influencing factors.