Industrial & Engineering Chemistry Research, Vol.59, No.15, 7238-7246, 2020
MgO-Kaolin-Supported Manganese Ores as Oxygen Carriers for Chemical Looping Combustion
Manganese ores used as oxygen carriers in chemical looping combustion (CLC) have attracted growing interest. However, the primary challenge of manganese ores is their tendency to produce fines and agglomerate. In this work, two MgO-kaolin-supported manganese ores were prepared to address the challenges of the reactivity, stability, mechanical strength, and melting characteristics of raw manganese ores. The reduction reaction of the MgO-kaolin-supported manganese ores is slower than that of raw manganese ore, but the stability of raw manganese ore can be improved. The crushing strength of the MgO-kaolin-supported manganese ores increased substantially from 3.05 N to more than 50 N. The attrition index decreased to 2.228 wt %/h; therefore, the high attrition resistance of manganese ores is achieved. The melting characteristics of the prepared oxygen carrier were discussed. MgO-kaolin-supported manganese ores show great promise in reducing attrition and increasing the operating temperature for enhancing char conversion in the fuel reactor.