3E analysis and mathematical modelling of garlic drying process in a hybrid solar-electric dryer

Abstract

The current study aims to explore the hybrid solar-electric drying (HSED) of garlic cloves, tests were carried out at three different temperatures 50, 60 and 70 °C under natural convection mode and forced convection mode. Drying air velocity of 4.1 and 6.9 m s−1 have been studied experimentally in forced convection mode. Midilli-Kucuk model can be used to predict the drying behaviour of garlic cloves. The energy payback time of the forced convection dryer are 0.62 and 0.32 years and the net CO2 mitigation was 72.61 and 140.81 ton for air velocity of 4.1 and 6.9 m s−1, respectively. The highest exergy efficiency of 89.86% was achieved at 50 °C drying temperature in natural convection, with a range of 69.61–89.86%. The highest environmental impact factor of 40.35 was observed for the lowest exergy efficiency. The proposed HSED in Algeria has a significant payback period of only 0.08 years compared to Morocco with 0.7 years. The effect of air velocity on the total phenol compound and 2-diphenyl-1-picryl hydrazyl (DPPH) was found to be significant, and the highest values were recorded for HSED under natural convection mode. The proposed HSED in Algeria was found to be sustainable both environmentally and economically.