Evaluation of thermo-kinetic and absorption characteristics of pure desiccants and desiccant mixtures

Air conditioning systems are used to control the air dry-bulb temperature and humidity level for human thermal comfort. In order to control the humidity level, air dry-bulb temperature needs to be brought down below its dew point temperature to condense out the moisture from the air. This eventually consumes a significant amount of total building energy in terms of electricity. Therefore, to minimize the energy consumption, researchers are stimulating their study towards an alternative latent heat load control system. In this regard, desiccant based sorption technologies are more effective compared to the conventional vapor compression system. Therefore, it is necessary to analyze the different desiccants' individual properties and their physical behavior in material perspective. In this study, an effort is devoted to explore the thermo-kinetic properties of pure LiBr, CaCl₂, as well as their mixtures (LiBr: CaCl₂ of 90:10; 85:15; 80:20 and 75:25) by X-ray diffraction (XRD), thermo-gravimetric (TG) and absorption rate, analyzes through numerous control experiments. The XRD study confirmed that peaks of CaCl₂ and LiBr were shifted slightly for LiBr and CaCl₂ mixtures due to interaction effects. The results of present investigation elucidated that mixtures of LiBr and CaCl₂ showed less moisture regeneration cost than pure CaCl₂ and all the mixtures revealed more rate of moisture absorption than pure LiBr and CaCl₂. Further, 85:15 mixture of LiBr:CaCl₂ showed higher rate of moisture absorption when compared to other prepared samples.