Indian Journal of Science and Technology

Abstract

The article focuses towards the study and characterization of the river sand suitability for high temperature thermal energy storage. The study is carried out preferably on the specific heat capacity of the river sand. A river sand sample from the banks of cauvery having the smallest grain size has been chosen. The sample undergoes the tests namely; Thermal Gravimetric Analysis (TGA), Fourier Transform Infrared Analysis (FTIR) and Differential Scanning Calorimeter (DSC). Detailed analysis is carried out to observe the sample’s change in weight when subjected to heating. FTIR analyzes the chemical groups present in the sample and DSC helps to identify its specific heat capacity which could justify the effect of thermal storage. TGA analysis showcased 1.013% of change in the sample weight during the first cycle of heating. However, during further heating cycle’s negligible change in weight is observed. Therefore, same sample could be used for several heating cycles without the need for replacement. The reason behind the weight loss was later examined by FTIR analysis. It is observed that the carbonate compound present in the sample was missing after heating. This test justifies the absence of carbonate compound presence after the heating process. The specific heat capacity of sand was found to be 1041 J/Kg/K by DSC analysis. The observed value of specific heat capacity of sand shows its superiority over the conventionally used high temperature thermal storage medium mainly molten salt and synthetic oils. The observation shows the heated sample with agglomeration due to the presence of other impurities and a considerable color change was observed. River sand is tested for its thermal characteristics and studied for the first time to the best of knowledge which the researchers are still at the finding stage. The specific heat capacity observed in the river sand makes its suitable for high temperature thermal energy storage in Concentrated Solar Power Plants (CSP).
Keywords: Phase Change Material, River Sand, Sensible Heat Storage, Specific Heat Capacity, Thermal Characterization, Thermal Energy Storage