Activation and Reactivity of Novel Calcium-Based Sorbents for Dry SO2 Control in Boilers

摘要

Chemically modified Ca(OH)2 sorbents for SO2 control in utility boilers were tested in an electrically heated, bench-scale isothermal flow reactor, operated at between 700 and 1000 C and residence times of from 0.6 to 2 sec calculated from bulk gas flowrates. Novel surfactant-modified Ca(OH)2--SM-Ca(OH)2--sorbents were compared to conventional Ca(OH)2 produced by dry hydration, DH-Ca(OH)2. Sorbents were activated in the flow reactor. Changes in the pore structure of Ca(OH)2 sorbents reacting with SO2 also were investigated. The effect of thermal sintering on pore structure of sorbents reacting with SO2 was eliminated. The degree of conversion was controlled by varying gas-phase mass transfer resistance (SO2 concentrations from 50 to 3000 ppm).