Sorption and desorption characteristics of a packed bed of clay–CaCl2 desiccant particles

Desiccants can be used in conjunction with solar energy to provide a viable alternative to traditional air conditioning techniques. A desiccant consisting of clay and calcium chloride was developed and tested using multiple sorption and desorption cycles. During sorption, inlet air temperatures from 23 to 36 °C with corresponding relative humidities of 42–66% were tested. Additionally, superficial air velocities from 0.17 to 0.85 m/s were tested. During desorption, inlet air temperatures from 50 to 57 °C and superficial air velocities of approximately 0.30 and 0.60 m/s were tested. A regression equation was determined for the mass of water sorbed by the clay–CaCl2 desiccant with a R2 value of 0.917. The desorption data was regressed to an exponential function and significant k-values were determined. An equation for pressure drop through the desiccant was determined and compared to existing models. The desiccant was found to perform well during the repeated test cycles though small masses of desiccant were lost due to surface disintegration of the desiccant spheres.