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

In this work a new family of sorbents, specifically designed for ethanol sorption, is presented. The composites were synthesized by impregnation of matrices with an aqueous solution of different salts. The ethanol sorption capacity of composites, under conditions of typical adsorptive air conditioning cycle, was measured by using an express method based on the Polanyi principle of temperature invariance. Results obtained showed that several of the composites synthesised present 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 per air conditioning and ice making cycles, respectively, that are much larger than those for conventional adsorbents. The correspondent thermodynamic cooling COP was estimated to be 0.66 and 0.61, which is comparable with typical cooling COP of the best water sorbents.