Ethanol/activated carbons working pair for adsorption cooling systems

The aim of the present paper is the experimental characterization of adsorbent materials suitable for adsorption refrigeration systems, employing ethanol as refrigerant. Different commercial activated carbons as well as a properly synthesized porous composite, composed of LiBr inside a silica gel host matrix, have been tested. A complete thermo-physical characterization, comprising nitrogen physi-sorption, specific heat and thermo-gravimetric equilibrium curves of ethanol adsorption over the sorbents, has been carried out. The equilibrium data have been fitted by means of the Dubinin-Astakhov equation. On the basis of the experimental data, a thermodynamic evaluation of the achievable performance of each adsorbent pair has been estimated by calculating the COP under typical working boundary conditions for refrigeration and air applications. The results demonstrated that the innovative composite material shows the highest thermodynamic performances in every working condition. Nevertheless, the best carbonaceous material reaches COP value comparable with the synthesized composite.