Experimental Study of the Drying of Hot Red Pepper in the Open Air, under Greenhouse and in a Solar Drier

Abstract

This work attempts to assess the efficiency and profitability of the greenhouse (used in agriculture) to dry agricultural products. It aims at studying and analyzing the drying of red pepper known as “Baklouti” by three different solar processes. These three drying processes enable us to profit from a free energy coming from the sun. Two experimental devices were used. Three drying kinetics were set up in a natural convection solar drier, under greenhouse and in open sun, respectively. Drying times (including nights) are about 73 hours in the dryer, 79 hours in the greenhouse and 118 hours in open sun. Six thin-layer drying models (Newton, Henderson and Pabis, Modified Henderson and Pabis, Wang and Singh, Logarithmic and Twoterm) were fitted to the experimental data to select a suitable drying equation. The Logarithmic was found to best describe the drying behavior of pepper for open sun, greenhouse and solar drier drying. The experimental results show that the solar tunnel greenhouse dryer must be improved to become competitive to the solar air dryer.