Operacao assistida por computador de um cristalizador evaporativo industrial de acucar.

This work aimed at the development of computer aided process operation strategies for an industrial semi-batch sugar evaporative crystallize. Today's computational power of industrial control systems allows the implementation of process operation methodologies based on deterministic and or stochastic mathematical models. However, the inadequacy of process models and the limited availability of reliable industrial sensors hinder the applicability of these methodologies. In this work mathematical models have been developed for the simulation of crystallization, through the use of mass and energy balances, and a population balance to characterize the crystal size distribution. A first model, without the agglomeration mechanism, was studied. A continuous domain solution is available for the population balance equation through moment transformation, the properties of the distribution being represented as functions of the calculated moments. The inclusion of the agglomeration mechanism precludes such type of solution. This difficulty was overcome by applying a discretization procedure to the population balance equation. A discrete model for growth with dispersion is thus proposed that along with a discrete model for nucleation and agglomeration and with the mass and energy equations constitute the model of the crystallize...Available from Fundacao para a Ciencia e a Tecnologia, Servico de Informacao e Documentacao, Av. D. Carlos I, 126, 1249-074 Lisboa, Portugal / FCT - Fundação para o Ciência e a TecnologiaSIGLEPTPortuga