Desorption-driven sorption cooling: a thermodynamic analysis of a variable-volume implementation
Year: 2026
Type: article
Abstract: This study investigates a desorption-driven sorption cooling approach as an alternative to conventional thermally regenerated adsorption cooling systems. The approach utilizes the endothermic heat of desorption directly for cooling by reducing the adsorbate partial pressure, potentially enabling operation near ambient temperature without an external regeneration heat source. As a representative implementation, a variable-volume adsorption cooling (VVAC) system is investigated, in which the required reduction in water vapor pressure is achieved through controlled expansion of the adsorber volume. The influence of the initial water vapor pressure and the ratio of final to initial adsorber volumes on system performance was analyzed using a simplified theoretical model for the zeolite-water working pair. Lower initial pressures and larger volume ratios (V 2 /V 1 ) were found to promote greater water desorption from both NaX and NaY zeolites. The initial amount of water desorbed from NaX reached approximately 0.25 g/g zeolite at an initial pressure of 0.5 kPa and V 2 /V 1 = 50, while NaY exhibited about 10%–35% higher desorption under comparable conditions. The calculations further revealed two characteristic operating regimes, in which the adsorbate partial pressure and water loading in the zeolite exhibited either decaying or approximately persistent oscillatory behavior arising from the coupling between vapor desorption and pressure variation. Under the idealized assumptions adopted in the present study, the minimum reversible work required to initiate the pressure reduction was found to be considerably smaller than the thermal energy released through the adsorption-desorption equilibrium, indicating favorable thermodynamic potential for the proposed concept. The results indicate the thermodynamic potential of pressure-induced desorption as a cooling mechanism in a water–zeolite adsorption system and provide a basis for further investigation of low-work implementations, including variable-volume operation.
Source: Frontiers in Thermal Engineering
Author: Melkon Tatlier
Institution: Istanbul Technical University
Language: English
Subfield: Mechanical Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,418
OpenAlex ID: W7213345618