A THERMODYNAMIC ANALYSIS OF JUICE PASTEURIZATION PROCESS

Abstract

A superior fruit or vegetable juice should be healthy and nutritious, in this purpose being heated and treated. Exergy analysis is a tool able to indicate whether or not and how it is possible to design more efficient energy systems by diminishing the inefficiencies existing in the analyzed systems. This analysis is considering the quantity and quality of the energy. Exergy efficiency evaluates the efficiency of a process by considering the second law of thermodynamics. Being seen that the production process of juices involves a lot of stages, is concluded that a significant amount of energy is consumed. For the improvement of this process are calculated exergy efficiencies for a pasteurization unit comprised in the juice production flow chart, when inlet hot water temperature is increased from 87 to 100^oC, by keeping the other parameters constant. Are obtained reduced values for the exergy efficiency together with the increment of the hot water temperature at the entrance of the pasteurization unit. Better values for the exergy efficiency are seen in the same operating conditions, but for a reduced mass rate of the hot water. For a decrease of about 82% of this mass rate the afferent average exergy efficiency is higher with about 80%.