The heat of immersion of several kinds of zeolites, i.e., molecular sieves 5A, 4A, improved mordenite, natural mordenite and natural clinoptilolite, against water was determined on the basis of the“absolute method”by using a highly accurate quartz temperature sensor.
In the case of zeolites the heat of immersion measurement at relative vapour pressure of about 0.2 was found suitable for the estimation of specific surface. The results were compared with the data obtained by other adsorption methods utilizing nitrogen, water vapour and CH3OH. The measurement of heat of immersion of zeolites against water requires little theoretical assumptions and is quite ingenious and considerably simple and reproducible for the estimation of specific surfaces. Although Itaya-zeolite showed less heat of immersion than molecular sieves 5A and 4A, it seems useful for heat recovery, in such fields as solar heating and cooling, or waste gas treatment.
