Reaction kinetics of Ca-based sorbents with HCl in fluidized bed

The capacity of CaO for binding HCl from incineration of organic wastewater which contains C₂H₃Cl₃O₂ was investigated at 500-800°C in a bubbling fluidized bed. The binding capacity was the largest at 600°C, and then decreased with increasing temperature. Scanning electron microscope (SEM) analyses showed that the rate-limiting step for the reaction altered with the extent of solid conversion in sequence at temperature exceeding 600°C: chemical reaction control, and simultaneous chemical reaction and product layer diffusion control for a long period of time. There was not a single product layer diffusion control. The experimental results were analyzed by using the unreacted shrinking core model. The activation energy of product layer diffusion was about 9.95 kJ·mol^-1 for the range of temperatures in the fluidized bed.