Experimental and modelling study of tomato pomace waste drying in a new solar greenhouse: Evaluation of new drying models

Algeria industry fruit processing generates a huge amount of waste which causes a serious environmental problem. Thereby, the use of solar drying as a clean energy process seems to be a promising solution. This will enhance the value of fruit waste by reusing it in a dry form, and will also contribute to the protection of the environment. For this purpose, an innovative greenhouse solar dryer has been designed at the Solar Equipment Development Unit in Bou Ismail. An experimental study of solar drying kinetics of industrial tomato pomace was conducted to test the performance of the new solar dryer as a waste processing dryer. The drying temperature of the tomato waste, using this type of dryer, varies between 40 and 58 degrees C. The duration of the drying operation for a final product is only 5 h. Five new universal and dimensionless models and five different drying models chosen from the literature were evaluated in order to select the model that better fits the experimental data generated during the drying process. Among the different models tested, it emerged that the new model2 was the most suitable to describe the drying process of tomato waste. Also, the diffusion coefficient and the activate energy were studied and determined. The effective diffusivity varies between 3.2E-9 and 4.7E-10 m(2)/s with activation energy is 75.6 kJ/mol. (C) 2018 Elsevier Ltd. All rights reserved.