Thermal Energy Storage Using Hybrid Nanofluid Phase Change Material (PCM) Based on Waste Sludge Incorp Rated...

Renewable solar energy storage facilities are attracting scientists' attention since they can overcome the key issues affecting the shortage of energy. A nanofluid phase change material (PCM) is introduced as a new sort of PCM is settled by suspending small proportions of nanoparticles in melting paraffin. ZnO/α-Fe₂O₃ nanocrystals were prepared by a simple co-precipitation route and ultrasonically dispersed in the paraffin to be a nanofluid-PCM. The behaviors of the ZnO/α-Fe₂O₃ nanocrystals were verified by X-ray diffraction (XRD) analysis, and the average particle size and the morphology of the nanoparticles were explored by transmission electron microscopy (TEM). For the object of industrial ecology concept, aluminum-based waste derived from water-works plants alum sludge (AS) is dried and augmented with the ZnO/α-Fe₂O₃ nanocrystals as a source of multimetals such as aluminum to the composite, and it is named AS-ZnO/α-Fe₂O₃. The melting and freezing cycles were checked to evaluate the PCM at different weight proportions of AS-ZnO/α-Fe₂O₃ nanocrystals, which confirmed that their presence enhanced the heat transfer rate of paraffin. The nanofluids with AS-ZnO/α-Fe₂O₃ nanoparticles revealed good stability in melting paraffin. Additionally, the melting and freezing cycles of nanofluid-PCM (PCM- ZnO/α-Fe₂O₃ nanoparticles) were significantly superior upon supplementing ZnO/α-Fe₂O₃ nanoparticles. Nanofluid-PCM contained the AS-ZnO/α-Fe₂O₃ nanocrystals in the range of 0.25, 0.5, 1.0, and 1.5 wt%. The results showed that 1.0 wt% AS-ZnO/α-Fe₂O₃ nanocrystals contained in the nanofluid-PCM could enhance the performance with 93% with a heat gained reached 47 kJ.