Experimental investigation of porous carbon for cooling and desalination applications

Adsorption cooling and desalination (ACD) system presents a solution for water, energy, and environmental dilemma. This study expresses an enhancement of adsorption system performance in terms of cooling and desalination effects by improving an activated carbon Maxsorb III (Max) as an adsorbent. Max has been initially treated with HCl. Then, it has been activated by impregnating it in salt hydrates ((NH₄)₂CO₃). Characterization methods, including XRD, N₂ and water adsorption isotherm, and water adsorption kinetics have been conducted for raw Max, treated Max, and activated Max with (NH₄)₂CO₃. The experimental values have been fitted with the Dubinin & Astakhov equilibrium model for isotherm and the model of linear driving force for kinetics. These fitted parameters have been utilized in a previously validated model to estimate adsorption cooling-desalination system performance with and without heat recovery. Max/(NH₄)₂CO₃ achieves a water uptake of 0.53 kg_H2O.kg^-1. Max/(NH₄)₂CO₃ produces 13.2 m³.ton^-1 of freshwater per day with a specific cooling power of 373 W.kg^-1 and 0.63 COP. Also, the freshwater reaches 22.5 m³.ton^-1 of Max/(NH₄)₂CO₃ per day with condenser-evaporator heat recovery. These results indicate the potential of utilizing the Max material in dual cooling and desalination applications to achieve double what silica gel can offer.