Abstract
In this work the inorganic and zeolite-hybrid desiccants were synthesized by the sol-gel method at room temperature and atmospheric pressure. The sol-gel method leads to the formation of highly crosslinked and transparent gels. Inorganic salts, i.e., NaCl, KCl, CaCl2, ZnCl2, MgCl2, MgSO4 and Mg(ClO4)2 were added to investigate the capacity of water vapor adsorption. It was found that CaCl2 gave the best result. Therefore, CaCl2 of 20%, 30% and 40% by weight were varied. The longer the aging time is, the higher the adsorption efficiency becomes. Subsequently, zeolite (JRC-Z-HY5.3) of 10%, 20%, 30% and 40% by weight were added to obtain the porosity and strength of the desiccant. The adsorption capacity of the synthesized desiccant increased with an increase in calcium chloride. From SEM micrographs, the surfaces of the desiccants adding calcium chloride of 20% and 30% by weight were not smooth and showed porous structures after adding zeolite. The adsorption capacity of the desiccant adding calcium chloride and zeolite increased, when the contents of zeolite increased to 40% by weight. The SiO2-30- wt% CaCl2-40-wt% zeolite showed the highest adsorption capacity at 100% RH. The water vapor adsorption of the SiO2-30-wt% CaCl2-40-wt% zeolite at 40%, 60%, 85% and 100 %RH were 32.14%, 54.48%, 74.30% and 96.84 %, respectively.
