1H NMR microimaging for studying the water transport in an adsorption heat pump

In this communication we present experimental results on the water transport in composite sorbents calcium chloride confined to mesoporous silica or alumina", that are promising for sorption cooling/heating. The study was performed by H-1 NMR microimaging technique the spatial and temporal resolution of which is found to be quite sufficient to measure the water concentration profiles inside a granulated bed, a consolidated layer or a single pellet of an adsorbent. Mathematical treatment of these profiles allows determination of the effective water diffusivity as a function of the water uptake. For the compact adsorbent layers the influence of the powder size, the content of the binder and the pore-forming additives on the layer mass transport properties is analysed.