Optimizing adsorption refrigeration with MOF-propane integration: a sustainable approach

Abstract

The adsorption refrigeration cycle (ARC) is a sustainable refrigeration process that fundamentally replaces the energy-intensive compressors in a vapor compression cycle (VCC) with an adsorbent bed that uses solar energy or waste heat for regeneration. This has been experimentally shown to be a sustainable alternative to the VCC cycles. Metal–organic frameworks (MOFs) have been proven to be excellent adsorbents compared to the traditionally used zeolites, silica gel, and activated carbon owing to their ordered structure and tunable characteristics. In this study, we explored the integration of MOFs with a proposed low-global warming potential (GWP) refrigerant, propane. Using propane as the refrigerant fluid, we performed a computational screening on the CoRE MOF database to identify the optimal MOFs for use as an adsorbent in this application. We discovered a maximum coefficient of performance (COP) for refrigeration of approximately 0.6, which is significantly higher than those obtained using widely used adsorbents like zeolites, silica gel, and activated carbon. We also investigated the cooling capacity (CC) of the MOF-propane pair and obtained a remarkable CC of around 95 kJ kg⁻¹. An insight into the structural characteristics of MOF that influence the COP and CC has also been studied. A further investigation of optimization of the cycle produced a maximum COP with 20% increase to 0.725, and the maximum cooling capacity improved to 190.2 kJ kg⁻¹. This work offers fundamental insights into choosing MOFs as adsorbents in ARC, which can in the future be explored to make the refrigeration process more sustainable.