异形催化剂效率因子的数值计算
Numerical Calculation of Effectiveness Factors of Non-Cylindrical Catalyst Particles
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摘要: 推导了用有限差分方程计算催化剂颗粒效率因子的方法,并计算了几种异形催化剂(三叶草形,圆柱形,五叶形,环形)的效率因子。计算结果表明:三叶草形催化剂在化学反应中的内扩散性能大大优于圆柱形;对于颗粒内扩散控制的催化反应过程,采用异形催化剂可以显著提高表观反应速度;在体积相同的条件下,四种形状催化剂的效率因子的大小为:环形>三叶草形>五叶形>圆柱形。提出了形状对效率因子影响的估值不等式。Abstract: The effectiveness factors of extruded catalysts of four different shapes were calculated numerically by finite difference method. The results of calculation show that the three-lobed catalyst is much better than cylindrical-shaped in diffusion behavior. When intra-particle diffusion limitation is important, the use of non-cylindrical catalysts can increase superficial reaction rate markedly. An evaluation inequality about the effect of catalyst shape on the effectiveness factor of catalyst is proposed.