Olefins readsorption-diffusion model

The mesoscale effects on the product distribution of FTS should include two points as follow (1) the modified ASF product distribution and olefin readsorption mechanism model and (2) diffusion-reaction model and external-internal diffusion model of FTS process. [Pg.366]

Recently, we reported detailed descriptions of hydrocarbon chain growth on supported Ru catalysts (7,8) we showed that product distributions do not follow simple polymerization kinetics and proposed a diffusion-enhanced olefin readsorption model in order to account for such deviations (7,8). In this paper, we describe this model and show that it also applies to Co and Fe catalysts. Finally, we use this model to discuss a few examples from the literature where catalyst physical structure and reaction conditions markedly influence hydrocarbon product distributions. [Pg.384]

The diffusion-enhanced olefin readsorption model described in Section III,C was used to predict the effect of carbon number on chain growth probability and paraffin selectivity. The model requires only one adjustable parameter the exponent c in a hydrocarbon diffusivity equation that depends on molecular size ( ), but that is identical for paraffins and olefins of equal size ... [Pg.269]