Performance of natural wax as phase change material for intermittent solar energy storage in agricultural drying: An experimental study

Abstract

Solar Air Heater (SAH) technology as a drying method for agricultural commodities is only active during the day and is highly dependent on the weather. Therefore, this study aims to investigate the effect of SAH coupled with phase change material (PCM) types of paraffin wax, soy wax, and palm wax as store energy materials to enhance the performance of conventional SAH. The PCM containers placed in the SAH are ex-bottles of milk cans which are numerous in the country due to the increase in consumption of milk by the people as an immunity enhancer during the Covid-19 pandemic. This is expected to improve the 3R (Reduce, Reuse, Recycle) strategy implemented to reduce environmental pollution. The tests conducted showed that the three types of PCM effectively improved the performance of SAH in drying agricultural commodities. The highest energy efficiency was achieved with paraffin at 30 %, 23.28 %, and 33.67 % while the highest exergy efficiency was achieved with palm wax at 20.27 %, 18.86 %, and 28.96 %, in three days respectively at different solar irradiation conditions.