Abstract
Aiming for a technology with high efficiency and low cost for carbon capture, chemical looping combustion (CLC) shows a promising potential. It allows the inherent separation of CO2 during the fuel combustion which happens in a nitrogen free reactor thanks to the direct reaction of the fuel with oxygen released from a solid oxygen carrier material (OCM). The development of suitable OCM is a challenge. In circulating fluidized bed (CFB) CLC, OCM must keep a high oxygen capacity, high redox kinetics with both air and fuel and good mechanical properties. Furthermore it should be low cost and have a low toxicity. Lately, a significant interest has been shown to mixed OCM, especially to materials derived from the calcium manganite CaMnO3-δ perovskite. CaMn1-xTixO3-δ has proved to have catalytic activity with respect to CH4 reduction. In the frame of BIGCCS, CaMn0.875.x-yFexTiyO3-δ OCM were produced from industrial chemicals by spray granulation which is an easily up-scalable process. OCM chemical composition of CaMn0.875.xFexTi0.125O3-δ was investigated for optimization of the spontaneous release of oxygen by the OCM (CLOU effect). The latter were measured using cyclic thermogravimetric measurements (TG) under redox atmospheres, simulating the conditions during CLC operation. It was shown that iron substitution improves the redox kinetics. The mechanical properties of OCM were also investigated at low and high temperature.
