Assessment of sorbent reactivation by water hydration for fluidized bed combustion application

Disposal of fluidized bed combustion (FBC) solid residues currently represents one of the
major issues in FBC design and operation, and contributes significantly to its operating
cost. This issue has triggered research activities on the enhancement of sorbent utilization
for in situ sulfur removal. The present study addresses the effectiveness of the reactivation
by liquid water hydration of FB spent sorbents. Two materials are considered in
the study, namely the bottom ash from the operation of a full-scale utility FB boiler and
the raw commercial limestone used in the same boiler. Hydration-reactivation tests were
carried out at temperatures of 40°C and 80°C and for curing times ranging from
15 minutes to 2d, depending on the sample. The influence of hydration conditions on the
enhancement of sulfur utilization has been assessed. A combination of methods has been
used to characterize the properties of liquid water-hydrated materials.