Reaction kinetics and adsorption equilibria in the vapor‐phase dehydration of ethanol

This work is an experimental assessment of the Langmuir‐Hinshelwood model of heterogeneous catalysis. The vapor‐phase dehydration of ethanol to diethyl ether, as catalyzed by cation exchange resin in the acid form, was the reaction chosen for study. Initial reaction rate data, determined from the integral kinetic data obtained experimentally, allowed selection of the most suitable rate equation from among several plausible equations derived in accordance with the above model. The Langmuir equilibrium adsorption constants in the rate equation were compared with the corresponding constants determined directly from pure component studies in a static adsorption system. The adsorption constants determined for the three reacting components by these independent methods showed definite order‐of‐magnitude agreement. The adsorption studies also provided significant information about the nature of the catalytic site. The extent of agreement in the constants determined by these two independent approaches is considered to be evidence of the theoretical validity of this model. Additional interpretation of the adsorption and kinetic data via this model suggests that the ethanol dehydration reaction proceeds through the reaction of adjacently adsorbed ethanol molecules.