Investigation of few-layered Graphene based adsorbents for hybrid adsorption cooling and water desalination

The increasing water scarcity has resulted in over 2 billion people not having access to freshwater supplies over the globe. To alleviate the freshwater scarcity, the focus has been on brackish and seawater desalination. However, most societies facing water scarcity also face high temperatures and require sustainable cooling, not only for comfort but also for food preservation. Conventional cooling systems are energy-intensive and utilise refrigerants of long-lasting environmental impacts, such as hydro-chlorofluorocarbon (HCFC) and Chlorofluorocarbon (CFC). However, the increasing energy consumption for cooling systems also causes major environmental problems related to energy production, such as air, water and thermal pollutions. Therefore, adsorption cooling emerged as a less polluting alternative for cooling cum desalination in urban and rural areas.
Nevertheless, low heat and mass transfer in current adsorption reactor designs lead to low energy conversion efficiency, hence poor clean water and cooling production. The adsorbent material is very influential on the overall performance of adsorption systems. Recently few-layered Graphene derivatives showed unique thermal and adsorption characteristics. This study investigates Graphene Oxide (GO) of 1-3 layers experimentally and numerically through 3D computational fluid dynamics simulation (CFD) modelling. The adsorption and thermal characteristics of Graphene Oxide were benchmarked against conventionally used Silica gel (SG). The results showed that GO enhanced the thermal diffusivity by 22%, the adsorption performance by 43 % and overall performance by 37%.