Effects of nonseparable kinetics in alcohol dehydration over poisoned silica‐alumina

Abstract

Abstract Methanol and ethanol dehydration over fresh and poisoned silica‐alumina have been used as a model system to demonstrate experimentally certain effects of nonseparable kinetics including the change in product distribution upon flow reversal in a reactor with a poisoning gradient. The rate expression r = kK A C A 1/2 /(1 + K A C A 1/2 + K W C W ) describes the epxerimental data for all reactions although the constants for ether and olefin formation are entirely different and vary between fresh and poisoned catalysts. The nonseparability of kinetics and the concomitant variation of K A , K W with poisoning are briefly discussed in terms of interactions between poison molecules and surface acid‐base sites.