积炭催化剂再生的分形维模型

Fractal Reaction Model for Combustion Regeneration of Carbon Deposited Catalyst

将分形维理论引入积炭催化剂与再生气体的烧炭反应系统，提出了积炭催化剂的分形维模型。在拟稳态条件下，按缩核模型求得解析解，并在此基础上分析了当反应受气膜扩散控制、灰层扩散控制和化学反应控制时，分形维对再生过程的影响。通过实验和参数估计确定了积炭催化剂表面的分形维数在２～３之间，从而验证了模型的正确性。

A coke-combustion system has been treated based on the fractal theory.A Shrinking -Core Model for regeneration of the used catalyst has been established.The model can describe the oxidation process of irregular surface coverd with coke.And the influence of fractal dimension on the reaction time which is controlled by film diffusion,ashlayer diffusion and surface reaction is theoretically discussed.The results indicate that the higher the fractal dimension D,the shorter the relative reaction time. The reaction time is also dependent on the other geometrical parameters,such as partical size,shape coefficient,etc.The fractal dimension D was experimentally estimated and its value ranged between 2～3.The comparison between calculated and determined coke conversion showed that the result obtained by fractal modelling was in agree with experimental data.