SIMULATION OF A CONCENTRATED JUICE PLANT USING A MIXED MODULAR ? EQUATION ORIENTED MODEL

D. NUÑEZ, M. GONZALEZ, N. PETRACCI, A. BANDONI

Rio de Janeiro, Brasil

Congreso; ENPROMER 2005; 2005

The purpose of this work is to present a plant simulation model and computational tool for the decision making process in a concentrated juice plant, using a mixed modular and equation-oriented approach. Five main areas have been considered in a typical apple concentrated juice process, corresponding each of them to a main stage identified in the flowsheet. They are: 1) washing and sorting, 2) pressing, 3) aroma stripping, 4) clarification, and 5) final evaporative concentration. Each module (stage) is modeled solving mass and energy balances, equilibrium relationships and design specifications for every unit using equation-oriented mode. On the other hand, the modules are sequentially connected each other so the whole flowsheet is solved by a sequential modular strategy. The pressing module is rigorously simulated following Gonzalez et al. (2000) model. The final concentration is carried out in a multi-effect evaporator that is simulated by means of a multi-effect evaporator routine developed by Gonzalez et al. (2001). The plant model is completed with mixers, splitters and tanks. It allows studying different raw material qualities, variation in enzymes concentration, different configurations for the pressing and re-hydration sectors, etc. The whole plant model is implemented in a spreadsheet, which can be accessed by a user-friendly interactive shell. As a whole, the model and user?s shell constitute a rigorous and very easy to use computational tool for supporting the decision making process in the daily operation of these plants. The fruit packaging and processing industry reports annual incomings of 350 MMUS$ at Argentina, being almost half of this total the external trade of pear and apple juice. Most of the juice processing plants use similar technology and are located in a compact region along the Black River in the south of the country, where 95 % of total apples and pears production takes place. Results are presented for a typical concentrated apple juice plant. The mixed equation-oriented and sequential-modular approach, and the physical and thermodynamic correlations used, makes it possible the simulation of any other concentrated juice plant with minimum changes. The purpose of this work is to present a plant simulation model and computational tool for the decision making process in a concentrated juice plant, using a mixed modular and equation-oriented approach. Five main areas have been considered in a typical apple concentrated juice process, corresponding each of them to a main stage identified in the flowsheet. They are: 1) washing and sorting, 2) pressing, 3) aroma stripping, 4) clarification, and 5) final evaporative concentration. Each module (stage) is modeled solving mass and energy balances, equilibrium relationships and design specifications for every unit using equation-oriented mode. On the other hand, the modules are sequentially connected each other so the whole flowsheet is solved by a sequential modular strategy. The pressing module is rigorously simulated following Gonzalez et al. (2000) model. The final concentration is carried out in a multi-effect evaporator that is simulated by means of a multi-effect evaporator routine developed by Gonzalez et al. (2001). The plant model is completed with mixers, splitters and tanks. It allows studying different raw material qualities, variation in enzymes concentration, different configurations for the pressing and re-hydration sectors, etc. The whole plant model is implemented in a spreadsheet, which can be accessed by a user-friendly interactive shell. As a whole, the model and user?s shell constitute a rigorous and very easy to use computational tool for supporting the decision making process in the daily operation of these plants. The fruit packaging and processing industry reports annual incomings of 350 MMUS$ at Argentina, being almost half of this total the external trade of pear and apple juice. Most of the juice processing plants use similar technology and are located in a compact region along the Black River in the south of the country, where 95 % of total apples and pears production takes place. Results are presented for a typical concentrated apple juice plant. The mixed equation-oriented and sequential-modular approach, and the physical and thermodynamic correlations used, makes it possible the simulation of any other concentrated juice plant with minimum changes