Self-poisoning in finite cylindrical catalyst pellets

A generalized two-timing technique and finite Sturm-Liouville integral transforms are used to derive theoretical expressions for the time-dependent effectiveness factors of finite-length cylindrical catalyst pellets of various aspect ratios. Parallel and series poisoning processes are considered with both film and pore diffusional resistances acting. For Thiele moduli of unity or less, it is found that infinite-cylinder results can be used with only trivial error but for Thiele moduli greater than 5 the effectiveness factors for pellets of unit aspect ratio, and shorter, differ markedly from their infinite cylinder counterparts