(217ee) Research On the Kinetics of Calcination / Carbonation Reaction of Ca-Based Sorbents in Simulated Suspension State

At present, the kinetics of calcination/carbonation reaction of calcium based sorbent was mostly studied for materials in the accumulation state, which is different with the actual engineering in the suspension state. Therefore, in order to close to the actual process, the controlled atmosphere furnace is used as test equipment for simulating suspension state, and the kinetic parameters of calcination/carbonation reaction of two limestone under different CO₂ concentration is investigated. The results show that: the model of limestone thermal decomposition process under different CO₂ concentrations was regarded as a randomly nucleation and growth model, that is. Moreover, the higher the CO₂ concentration in the atmosphere, the higher activation energy of limestone thermal decomposition could be. Absorbent carbonation reaction is divided into two sections of chemical control stage and diffusion control stage. The model of chemical control stage reaction is a randomly nucleation and growth model and diffusion control reaction is the contraction spherical interface reaction model, that is. The activation energy of two stages reduces along with the increase of CO₂ concentration in atmosphere. In addition, the activation energy of chemical control segment is higher than the diffusion control segment.