The Rates of Solar Energy Storage and Retrieval in a Zeolite-water System

Abm'aet--The salient features that determine the possible use of a water vapour-zeolite 13X system as a method of energy storage were investigated. Cycling studies over two months revealed no decrease in water capacity nor any structural deterioration. The rate at which water could be desorbed in a static situation was determined at various temperatures from 110 to 250°C. The adsorption isotherm and the heats of adsorption as a function of amount of adsorbed water were determined. The saturation capacity was 0.33 g H20/g zeolite while the heat of adsorption declined from 90 to 50 IO mo1-1. The rate of heat development was found to be very high so that heat extraction from the store would not be a problem in any practical utilization of this system.