Novel sorbents of ethanol “salt confined to porous matrix” for adsorptive cooling

In this paper a new family of sorbents, specifically designed for ethanol sorption, is presented. The composites were synthesized by a dry impregnation of matrices with an aqueous solution of various salts. The ethanol sorption capacity of the composites, under conditions typical for adsorptive air conditioning cycle, has been measured by using an express method based on the Polanyi principle of temperature invariance. Results obtained show that the best novel composites have the ethanol sorption ability which is higher than that of known ethanol sorbents. The composite LiBr(30 wt.%)/SiO2 appears to show the highest sorption capacity and an uptake variation Δw = 0.56 and 0.40 g/g for air conditioning and ice making cycles, respectively. They are much larger than those obtained for conventional adsorbents. The correspondent cooling coefficient of performance (COP) was estimated to be 0.66 and 0.61, which is comparable with the COP of the best water sorbents.