Study of metal–organic framework (MOF)/water pairs for adsorption heat transformer applications

Abstract

Metal-organic framework (MOF), an advanced category of porous coordination polymers, has recently gained prominence as a novel class of adsorbent materials, captivating the attention of researchers worldwide engaged in diverse applications related to adsorption. An adsorption heat lifter or adsorption heat transformer (AdHT) plays a crucial role in elevating the temperature of a waste heat source. This is achieved by harnessing the adsorption enthalpy or isosteric heat of adsorption. The system performance of the AdHT system is affected by the working pairs, which leads to a possible application for MOF/water working pairs in such a system. In this study, 2-tank and 3-tank systems are invoked to investigate and compare the coefficient of performances (COPs) of three MOFs: MOF–801, aluminum fumarate, and MIL–100(Fe) paired with water while considering an atmospheric temperature of 308.15 K. With a waste heat source and cooling water temperature difference (TD) of 70 K in the 3-tank system, MOF–801/water outperforms aluminum fumarate and MIL-100(Fe). Considering a temperature driving force that explains the temperature change of heat transfer fluid during the flowing procedure inside pipes, ΔT = 5 K, the MOF–801/water pair can provide a gross temperature lift of around 30 K at a relatively good COP of 0.4867. There are very few articles that studied the MOFs/water pair for AdHT 2-tank and 3-tank system applications. Hence, the results of this study highlight their viability for designing environmentally friendly and energy-efficient heating systems.