Exergoeconomic performance assessment of a pilot-scale spray dryer using the specific exergy costing method

In this study, exergoeconomic analysis was performed to evaluate the performance of a pilot scale spray dryer during white cheese powder production by the specific exergy costing (SPECO) method. Drying experiments were carried out at an inlet drying air temperature range of 160–230 °C, an outlet drying air temperature range of 60–100 °C and an atomisation pressure range of 294.2–588.4 kPa. The components of drying system were separately analysed and the effects of operating conditions on system components and the overall system were discussed. Improvements for the drying cabinet should be focused on for process optimisation, whereas structural improvements of the atomiser should strongly be considered for reducing investment costs. Furthermore, investment costs for the feed pump used in the drying system should be decreased or the feed pump should be replaced with a cheaper one. While results showed high inlet and low outlet air temperatures caused high effectiveness for the overall system performance, the operating costs were the most important variable due to expenses.