Exergetic and exergo-economic assessment of orange juice pasteurization unit

Pasteurization of orange juice is a critical food safety measure commonly achieved through heat treatment of the same at 92 °C for 20 s so as to secure microbial inactivation to provide better shelf life. Pasteurization, being an energy intensive process, consumes 0.932 MJ/kg of thermal energy which causes considerable amount of exergetic degradation. In light of this, the objective of present research endeavor is to get in – depth understanding of energy, exergy and exergo-economic aspects of pasteurization activity by way of unearthing all associated derivatives such as energy efficiency, exergy efficiency, energy improvement potential, exergy improvement potential and sustainability index of the Orange Juice Pasteurization Plant. The specific application of second law of thermodynamics along with its integration with economic formulations from Specific Exergy Costing Method (SPECO) generates a platform where thermodynamic and thermo-economic outcomes are summarized for better diagnosis of operational deficiencies. Further, the exergy efficiency, specific exergy destruction and specific exergy improvement potential were computed as 75.97%, 125.22 kJ/kg and 74.88 kJ/kg while, thermo-economic derivatives such as levelized cost rates, specific cost of exergy destruction, cost rate of exergy destruction, total operating cost rate and specific manufacturing cost, were computed as 44.89 Rs./hr., 0.026 Rs./kJ, 1700.06 Rs./hr., 1744.95 Rs./hr. and 3.29 Rs./kg respectively. The present assessment develops a clear picture of energy related degradation along with detailed information about energy saving potentials available with the plant. It is pertinent to mention that a systematic approach aimed at energy conservation would consequently lead to improvement in sustainability as well as economic characteristics of plant. Thermodynamic and Thermoeconomic Analysis have been performed in current research initiative. The First and Second Law Efficiencies were calculated as 91.95% and 75.97% respectively. The Second Law based Cost of Exergy Destruction is computed as 0.026 Rs. /kJ. Hourly Operational Cost of Orange Juice Pasteurization Plant was calculated as 1744.95 Rs. /hr. The Specific Cost of Processing raw Orange Juice was estimated as 3.29 Rs. /kg.