Process simulation and economic analysis of radio frequency and solar energy assisted apricot drying system

Turkey's apricot production is a fact known to be among the leading countries. The design and economic evaluation of the drying systems used in the dried apricots production is an important issue. For this purpose, simulation and economic studies of combined radio frequency drying and solar energy assisted air drying systems used for the production of dried apricots were carried out. The drying behavior and kinetics of apricots in the drying system under different conditions were investigated. It was observed that the drying rate decreased over time. The Midilli equation was used to model apricot drying kinetics. The effective moisture diffusion coefficient was calculated using Fick's second law. Under optimum conditions, diffusion coefficients were found to be 4.96*10-9 m2/s for pre-drying and 7.32 * 10-9 m2/s for RF dryer. Economic analysis of different drying scenarios under optimum conditions was made with the SuperPro Designer simulation program. For the scenario under consideration, the total capital investment of the drying system was 328,115 $ and the payback time was 26.11 years. The effects of capacity change in different drying scenarios, main product price, electricity price, and working time of business on profitability were investigated. It was observed that main product price had a great impact on profitability. Also, the specific energy consumption (SEC) and energy efficiency of the system were calculated by performing energy analyzes with SuperPro Designer. It was observed that SEC of RF dryer (8.95 kW-h/kg water) was higher than SEC of the pre-dryer (1.36 kW-h/kg water).