Optimization of Energy Consumption of a Microwave-Assisted Continuous Pilot Plant for the Disinfestation of Broad Beans using Energy Modelling

Abstract

Microwave (MW) technology is widely used in food processing and represents a promising physical alternative to chemical fumigants and powders traditionally used to control insect infestations during post-harvest storage. Several studies have demonstrated that MW treatments can ensure high mortality of parasitic insects at different life stages while avoiding chemical residues and preserving product quality. In recent years, increasing attention has been devoted to the optimization of energy consumption in food processing technologies to improve process sustainability. In the present work, the electrical energy consumption of a continuous MW pilot plant for the disinfestation of broad beans (Vicia faba) was experimentally investigated and modeled. Experimental tests were carried out under different operating conditions by varying the electrical power supplied to the magnetrons (2.25–7.50 kW) and the residence time of the product inside the treatment chamber (123–415 s). The experimental data were used to develop empirical polynomial correlations describing the relationship between the specific energy supplied to the product and the total electrical consumption of the system. These correlations were used as interpolation tools to identify the operating conditions associated with minimum electrical consumption within the investigated experimental range. The analysis shows that suitable combinations of electrical power and residence time allow electrical energy savings of up to approximately 25% while maintaining the effectiveness of the treatment. The proposed model is intended as an empirical interpolation tool for the optimization of the investigated pilot plant and should therefore be applied only within the tested operating conditions, without extrapolation to different systems or operating ranges. Nevertheless, the approach proposed in this study provides a methodological framework that can be applied to other microwave treatment systems, allowing the experimental calibration of similar energy-consumption models for different plant configurations and operating conditions.