APPLICATION OF CRTA TO THE STUDY OF MICROPOROSITY BY THERMODESORPTIONOF PREADSORBED WATER

Thermodesorption is here considered for its possibility of giving acce ss to the microporosity of adsorbents. The requirements of this applic ation (good separation of successive desorption steps, good control of the desorption pressure and temperature throughout the sample, possib ility of a safe kinetic analysis of each step) are here fulfilled by c arrying out the thermodesorption in the Controlled transformation Rate Thermal Analysis (CRTA) mode. The method is applied to 4 zeolites (3A , 4A, 5A and 13X) and a well characterized charcoal, from -25 to 325-d egrees-C, after pre-adsorption of water.