Performance comparison between dolomite and limestone in fluidized bed Ca-looping cycles for CO2 capture

The CO2 capture capacity and the attrition behavior of a dolomite were studied during calcium looping cycles in a lab-scale fluidized bed. Results were compared to those obtained with six limestones in similar tests. The experiments were carried out under conditions representative of a process with calcination in an oxy-firing environment (T=940°C, CO2=70%v/v), with or without the presence of SO2. Results showed that the CO2 capture capacity of the dolomite was larger than that of the limestones, in spite of the lower calcium content of the sorbent. The presence of SO2 depressed the sorbent CO2 capture capacity. Contrary to limestone, the dolomite was subject to extensive attrition and fragmentation.