Influence of External and Internal Mass Transfer on Selectivity

Influence of External and Internal Mass Transfer on Selectivity 

Mass transfer resistances lead to a lower effective rate compared to the intrinsic chemical reaction, but may also significantly change the selectivity of parallel and consecutive reactions. In the following, this is discussed for two first-order reactions occurring in series or parallel, for simplification, the influence of external mass transfer is only discussed for a non-porous catalyst (to exclude pore diffusion), and the effect of pore diffusion is examined for a negligible influence of external mass transfer. Other more complicated cases are treated elsewhere (Baerns et al, 2006 Levenspiel, 1999 froment and Bischoff, 1990). 

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