Short residence time of the sorbent in the gas and formation of a dense layer of reaction product surrounding its surface influence the sulfur removal efficiency. A practical means of improving the process performance is to em- ploy fluidized-bed reaction in replacement of entrained-bed reaction normally used in cool-side desulfurization. This paper describes cold-modeling study of a circulating fluid-bed reactor. Several aspects of the problem are discussed: flu- idization behavior of CaO, attrition of the sorbent and solids entrainment from the fluid bed. Mechanisms and key controlling parameters are identified, and an integral model based on rate of attrition and mass balance is developed for predicting steady-state mass flows and particle-size distributions of the system. A process flow scheme is finally proposed for conducting desulfurization tests in the second stage of the study.
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