Performance evaluation of solar-assisted heat pump dryer integrated with thermal energy storage for drying Moringa Oleifera leaves

Open sun drying is the conventional approach used in the majority of developing countries to dry agricultural products. However, this method exposes agricultural products to a number of hazards, including microbial contamination, quality deterioration, and loss from animals. Heat pump drying has recently been found to be an effective drying technique for drying industries because drying parameters can be easily controlled and it preserves the quality of the dried products. Furthermore, combining a heat pump dryer with a thermal energy storage system appears to be a viable option for all-weather drying. In this study a novel solar-assisted heat pump dryer with thermal energy storage has been developed and tested for drying Moringa Oleifera leaves. The efficiency of the developed dryer was evaluated in the present work through thermal performance and proximate analyses. Experiment results show that the developed dryer preserved nutrients such as fat, ash, protein, fiber, and carbohydrates. In five hours of the drying process, the moisture content was reduced from 75.7 to 3.3%. The average COP value was 3.36, confirming the dryer's low energy consumption.