多孔颗粒内气体传递反应双阶段描述

DUAL-STAGE MODEL FOR THE TRANSPORT-REACTION IN POROUS PARTICLES

本文采用双阶段模型描述多孔颗粒与气体的传递反应。反应分为两个阶段:气体反应物在扩散进入颗粒内部同时与颗粒发生反应的第一阶段;形成产物层后,扩散和反应用双区域模型来描述的第二阶段。分析发现,蒂勒数是描述过程特性的重要参数,同时反映反应和扩散速度的影响,且与总阻力存在一定关系。利用TGA进行了脱硫反应实验,分析了反应温度、颗粒大小等对反应的影响,实验结果很好地证实了理论分析结论。

The dual-stage model was proposed to describe the transfer reaction process in porous particles. In the first stage, gas reaction diffuses into the inner of the particles and reacts with the solid to form a product layer covering whole particle. In the second stage, gas reaction diffuses through the product layer into the reaction zone and is absorbed by the solid. Thiele number was found to be an important parameter describing the process, which can give the influence of chemical reaction resistance, diffusion resistance and has some relations with the overall resistance. The influences of reaction temperature and particle sizes to the transfer-reaction process were analyzed. The predictions of the model were in good agreement with the TGA experiments.