Kinetics of the dehydration of alcohols in presence of tricalcium phosphate

Abstract

An investigation has been made into the kinetics of the dehydration in presence of tricalcium phosphate as catalyst of ethyl, n-propyl, isopropyl, n-butyl, and isobutyl alcohols. 1. It has been established that in presence of tricalcium phosphate the dehydration of alcohols proceeds in a very selective fashion, the content of unsaturated compounds in the gas being 98–99%. 2. It has been found that in presence of tricalcium phosphate secondary alcohols are the most readily dehydrated, then follow the iso-alcohols, and finally the normal alcohols. The rate of dehydration of normal alcohols falls with fall in molecular weight. 3. It has been established that when the phosphate catalyst is calcined its activity in the alcohols-dehydration reaction is greatly reduced. 4. It has been shown that when an α- orβ-hydrogen of ethanol is replaced of methyl the activation energy is lowered in a manner similar to that already observed for dehydration in presence of other catalysts. 5. It has been found that potassium carbonate, which is a promoter for the phosphate catalyst in the dehydration of formic acid, is a powerful poison for it in the dehydration of alcohols. 6. It has been shown that diethyl ether is not an intermediate product in the formation of ethylene from ethyl alcohols.