Optimization of Energy Consumption of a Microwave-assisted Continuous Pilot Plant for the Processing of Shelled Almonds

Energy efficiency is nowadays an essential requirement for sustainable food processing. This article introduces a numerical model for the optimization of electricity consumption of the prototype built for the disinfestation of shelled almonds. Previous studies have investigated the use of microwave technology, as an alternative physical process to the traditional chemical processes, for the disinfestation of almonds during the post-harvest storage phase. They defined the operating parameters of the machine to guarantee 100 % mortality of the insect at different life stages, without affecting the quality parameters of the product. In this study, experimental tests were carried out on the pilot plant to determine the electrical consumption of the prototype, by varying of discrete quantities the overall power of the prototype (range 2.25-7.50 kW) and the residence time in the treatment chamber (range 82-202 s). The results of the experimental tests were used to build the energy model in order to predict the energy consumption as a function of the main operating parameters and therefore to define the optimal operating conditions. The proposed mathematical model made it possible to map the optimal operating conditions and to adjust the pilot plant according to the type of treatment, highlighting the possibility of reducing electricity consumption by up to approximately 10%.