Performance analysis of infrared film drying of grape pomace using energy and exergy methodology

Abstract

In this study, grape pomace was dried in an infrared film dryer at 40, 45 and 50 °C surface temperatures to investigate the effects of heat transfer mechanism (natural and forced convection) and homogeneous drying on specific energy consumption, drying rate and drying time. Also, energy and exergy efficiencies were calculated. The average specific energy consumption values were calculated as 5.90, 4.49 and 4.07 kWh/kg in natural convection (Group 1) and 11.90, 11.32 and 11.81 kWh/kg in forced convection (Group 2), respectively. The maximum energy efficiency was observed as 54.71% at 45 °C in Group 1. Energy efficiencies at the experiments in Group 1 were found to be nearly 10% higher than Group 2. The maximum exergy efficiency was observed as 38.46% at 50 °C in Group 1, and the average exergy efficiency values for Group 1 and 2 were calculated as 34.84% and 33.76%, respectively. Group 2 experiments provided a faster drying process as expected. However, although forced convection was more effective in terms of drying time, natural convection was found more suitable considering all the performance parameters as a whole. This study offers a solution to dry grape pomace high quality, homogeneously and efficiently for industrial usage. © 2020 Elsevier Ltd