Experimental simulation of solar drying of garlic using an adsorbent energy storage bed

Solar drying of garlic with energy storage in silica gel is experimentally simulated in a closed system in which the air is continuously circulated between food and adsorbent. Kinetics of the drying process are studied and equilibrium data are predicted by a mathematical model developed from the experimental results. By comparing the end points of drying with equilibrium values the length of the drying process can be established.From sorption data, a garlic surface area of 63–188 m² g^?1 and a heat of adsorption in the first layer of 2548–2691 kJ kg^?1 have been calculated. A value of 746 kJ kg^?1 has been deduced for the activation energy for water removal.