Abstract: | Mixed solid solution spinels impregnated with cerium, Ce/MgO·MgAl2-xMxO4 (M=Fe, V, Cr, x≤0.4), were studied for controlling the SOx emission from the fluid catalytic cracking (FCC) regenerator. An insufficient sulfur release problem inherent to the earlier De---SOx catalyst, Ce/MgO·MgAl2O4, was effectively overcome by incorporating a transition metal into the spinel structure. Studies of the SOx pick-up, temperature profile for the sulfate reduction, the thermal analysis, and the De---SOx cycle test in the batch as well as the automated continuous reactor are discussed to define the role of a transition metal in the mixed spinels for the De---SOx performance. These advanced De---SOx catalysts have led to a commercial success for the simultaneous control of SOx and NOx emissions from the FCC regenerator. |