Energy-efficient mixed-mode solar drying using nano-enhanced PCM and desiccant-assisted thermal management for agro-products
DOI:
https://doi.org/10.65746/jbrha115Keywords:
solar drying; nano-enhanced PCM; thermal energy storage; photovoltaic tracking system; desiccant dehumidificationAbstract
This study presents an energy-efficient mixed-mode solar drying system integrating nano enhanced thermal storage and desiccant dehumidification to improve the continuous drying of agricultural products. A dual-axis photovoltaic (PV)-powered forced convection dryer was developed and coupled with paraffin wax phase change material (PCM) incorporated with 2 wt% Al₂O₃ nanoparticles and a solar-regenerated bentonite–CaCl₂ desiccant bed. Material characterization using SEM, DSC, TGA, and FTIR confirmed stable nanoparticle dispersion, enhanced thermal conductivity, and preservation of chemical integrity within the composite PCM. Drying experiments for turmeric (Curcuma longa) rhizomes were conducted under three modes: (i) forced convection, (ii) forced convection with nano-PCM storage, and (iii) nano-PCM combined with desiccant-assisted dehumidification. The hybrid system significantly reduced drying time, with unsliced turmeric drying in 48, 24, and 22 h, and sliced samples in 36, 18, and 14 h across the respective modes. Compared to traditional open sun drying (95 h), the system improved energy utilization, sustained drying during off-sunshine h, and delivered superior moisture management. The integration of nano-PCM and desiccant technology demonstrated substantial potential for energy recovery, extended operational duration, and improved environmental performance, marking a practical and sustainable solution for post-harvest agro-processing.
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