Cooling Performance Evaluation of Sustainable Adsorbent Material in Sorption System

This article explores the synthesis of activated carbon from agricultural waste, specifically rice straw, which is then employed as a sustainable adsorbent in an adsorption system utilizing ethanol as a refrigerant. A comprehensive thermodynamic assessment of cooling performance is conducted, encompassing cooling energy, and uptake efficiency for an adsorption system, using the MATLAB R2021b platform. Pore structural and morphology analyses reveal that the synthesized activated carbon boasts a specific surface area of 1241 m2/g and a total pore volume of 0.8537 cm3/g with a micropore volume of 0.766 cm3/g, showcasing a distinct honeycomb structure on its surface. Notably, at a desorption temperature of 90 °C, the volumetric cooling energy for the proposed activated carbon-ethanol pair is calculated to be 233.29 MJ/m3 at an evaporator temperature of 10 °C, representing a remarkable 2.5-fold increase compared to the ACF20-ethanol pair reported in the existing literature. Additionally, the study identifies the minimum and optimum desorption temperatures as 52.5 °C and 72 °C, respectively, for maximizing the desired cooling effect under 3.11 kPa evaporator conditions. These findings highlight the operational conditions where the cooling performance is optimized, thereby enhancing the overall efficiency of the adsorption system. This work represents a significant step towards addressing the challenges of waste management by transforming agricultural waste into valuable products, thereby aligning with the principles of circular economy and carbon footprints.