kinetic modeling of catalyst deactivation in conversion of methanol to olefins

The deactivation of the catalyst in conversion of methanol to olefins over zeotype catalysts was studied a two-step autocatalytic reaction network was considered for methanol conversion reactions a rate expression, first order in methanol feed concentration and activity, which is an approximation of concentration-dependent deactivation kinetic, was used for modeling reversible catalyst decay, that is, deactivation by coke formation a correlation was obtained between methanol conversion and time on stream methanol conversions showed the reverse s-shaped form with time which is observed in practice a correlation was developed for catalyst lifetime as a function of damkohler number and dimensionless rate constants ratios it was found that for a given catalyst the lifetime is strongly affected by methanol concentration in the feed with a weak dependence on space velocity of the feed the catalyst lifetime is roughly inversely proportional to methanol concentration in the feed which is consistent with the literature experimental data