Analysis of catalyst effectiveness in trickle-bed reactors processing volatile or nonvolatile reactants
Analysis of catalyst effectiveness in trickle-bed reactors processing volatile or nonvolatile reactants
复制标题
处理挥发性或非挥发性反应物的滴流床反应器中的催化剂有效性分析
DOI：
10.1016/0009-2509(80)87004-7
复制
发表时间：
1980
影响因子：
4.7
通讯作者：
M. Duduković
中科院分区：
文献类型：
--
作者：
P. Mills;M. Duduković
扩散和一级反应的问题，在催化剂颗粒的外表面是部分润湿的，如在滴流床反应器中遇到的;制定占所有感兴趣的情况下，如气体或液体限制反应物，有限或可忽略的外表面电阻，和挥发性或非挥发性液体。它示出的问题，评估催化剂的有效性的板，圆柱形，或球形的结果在一个一般的双系列方程，对于一个给定的几何形状，可以减少到各种感兴趣的情况下，通过适当的分配干和湿表面的毕奥数。催化剂效率因子由一个简单的表达式给出，该表达式仅依赖于Thiele模量和第一系列系数，该系数是通过使用加权残差法的双系列的数值解而得到的。近似公式预测的有效性因子与更精确的数值解预测的有效性因子之间的比较表明，这些前一种表达式低估了催化剂的有效性，因此可以安全地用于初始设计估算。说明和量化了接触效率对非挥发性液体限制和气体或挥发性液体限制反应物的催化剂有效性的相反影响。采用反应研究，以确定接触可能的陷阱进行了讨论。
The problem of diffusion and first-order reaction in catalyst pellets whose exterior surface is partially wetted, as encountered in trickle-bed reactors; is formulated to account for all cases of interest such as gas or liquid limiting reactants, finite or negligible external surface resistance, and volatile or nonvolatile liquids. It is shown that the problem of evaluating catalyst effectiveness for a slab, cylindrical, or spherical shape results in a general dual-series equation which for a given geometry may be reduced to a variety of cases of interest by proper assignment of Biot numbers for dry and wetted surfaces. The catalyst effectiveness factor is given by a simple expression that depends solely on the Thiele modulus and first series coefficient which is found by numerical solution of the dual-series using the method of weighted residuals. A comparison between effectiveness factors predicted by approximate formulas to those given by the more accurate numerical solutions suggests that these former expressions underestimate the catalyst effectiveness and consequently are safe to employ for initial design estimates. The opposite effect of contacting efficiency on catalyst effectiveness for nonvolatile liquid limiting and gas or volatile liquid limiting reactants is illustrated and quantified. Possible pitfalls of employing reaction studies to determine contacting are also discussed.