Fundamental Studies of Sorbent Calcination and Sulfation for SO2 Control from Coal-Fired Boilers

摘要

The report gives results of a laboratory-scale investigation of the reactivity of calcium-based sorbents for SO2 capture after calcination at furnace operating temperatures (1200-1950 C). This work was undertaken to provide fundamental information for developing SO2 emission control technology in pulverized-coal-fired utility boilers. Pulverized sorbents (< 100 micrometer diameter) were calcined by injection into a laboratory gas flame reactor. Experimental variables were time, temperature, gas composition, limestone type, and particle size. Samples were collected for analysis of surface area, extent of calcination, particle size distribution, and reactivity toward SO2. Particle heating, calcination, and surface area development occurred typically in 25-35 ms. Flyash materials reduced both the surface area and the SO2 reactivity of the sorbents tested: calcite was affected the most, and dolomite the least. An approximately linear correlation was found between SO2 reactivity and specific surface area which covered both limestones and limestone/mineral mixtures.