Modelo de ordem reduzida de uma coluna de destilação extrativa salina em estado estacionario

AUTOR(ES)
DATA DE PUBLICAÇÃO

1996

RESUMO

One of the major difficulties at mathematical models of staged separation systems is the large dimensionlity of the process models. These models introduce significant computational effort especially in cases involving repetitive simulations such as optimization and dynamic simulation for control systems The need of the efficient process models which require a smaller computational effort has motivated the reduced-order models developement. In this work is developed reduced-order models to steady-state distillation columns for ethanol-water system using salt effects for breaking the azeotrope, throught the aproximation method (orthogonal collocation). The discontinuities in column profiles, introduced by feed, are contoured by dividing the column into sections, where he composition profiles, in each section, are aproximated using continuous polynimial. These aproximations reduced drastically the number of equations requeried to describe the process. The utilization of salts as the separation agents in extrative distillation process make the reduction of the column dimensions possible and the agent amount used. The addition of specific salts in the ethanol-water system alter the vapor-líquid equilibrium relationship of the system in a manner favorable to the separation. The salts used in this work as separation agents were calcium chloride (CaCh), potassium acetate (KC2O2H3) and litium chloride (LiCl). The thermodynamic model employed to describe the activity coefficients in the mixed solvent/salt systems is a extended UNIQUAC model. The results, got form the extractive distillation column simulation, showed a good agreement with the model tray-to-tray, processing time decreasing

ASSUNTO(S)

salinas destilação polinomios ortogonais metodos de simulação azeotropo

ACESSO AO ARTIGO

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