FRAGMENTATION OF CALCIUM-BASED SORBENTS UNDER HIGH HEATING RATE, SHORT RESIDENCE TIME CONDITIONS

A laser heating technique was developed to study the fragmentation behaviour of calcium-based sorbents under high heating rate, short residence time conditions. Eight geologically dissimilar, commercially available calcium-based sorbents were tested in the reactor using particle sizes in the range 37-105 mu m. The fragmentation behaviour was a function of sorbent type, particle size and particle temperature over the range of 600-1600 degrees C, with the sorbent type being the dominant parameter. Dolostones were more susceptible to breakage than limestones. The mechanism proposed for the fragmentation of the dolostones involves the rapid decomposition of the magnesium carbonate, which builds within the particles a sufficiently high pressure of CO2 to overcome the inherent mechanical strength.