HEATS OF CHEMISORPTION OF N-ALIPHATIC ALCOHOLS ON ALPHA-AL2O3 AT 25-200-DEGREES-C - A THERMOKINETIC STUDY

A differential microcalorimeter (E. Calvet) was used to study the proc esses of adsorption of five aliphatic alcohols (C-1-C-5) on Cl-Al2O3 a t 25, 50, 100, 150 and 200 degrees C. In particular, the importance of the thermokinetic study of the chemisorption of such alcohols at diff erent experimental temperatures was demonstrated, with regard to the v ariations in the thermokinetic parameters (t(max), t(1/2) and t(o)) an d the evolution of the alcohol vapor pressure on the adsorbent during the adsorption process. It was concluded that: a) all the heat emissio n peaks of alcohol adsorption have the same rounded shape at 25 degree s C; b) on passing from methanol to 1-pentanol, the area of the adsorp tion peaks increases as the chain length or molecular weight increases ; c) on passing from 25 to 200 degrees C, the shape of the adsorption peaks becomes more pointed.