Examinando por Materia "PINCH POINTS"

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  • Miniatura
    PublicaciónAcceso abierto
    Cálculo e interpretación de las trayectorias de puntos de composición constante (pinch) en columnas simples de destilación para mezclas azeotrópicas homogéneas
    (2013-11-14) Sánchez-Correa, César Augusto
    A continuation method of the kind predictor-corrector is presented for completely tracking of the pinch points branches related to the products or pseudoproducts of a homogeneous azeotropic distillation column. The method easily handles the turning points allowing the localization of the tangent pinch points. The foundation of the concept is in the ideas of Fidkowski, Malone y Doherty; however, some novelties are included, as the initiation strategy for calculations, the way to obtain the tangent vector and the set of equations on which the technique is applied. Three examples are illustrated with the solutions of acetone + chloroform + benzene, acetone + chloroform + methanol and acetic acid + amyl alcohol + amyl acetate, emphasizing cases that show better separation possibilities in the finite reflux condition than with total reflux operation.
  • Miniatura
    PublicaciónAcceso abierto
    Herramientas geométricas para el diseño básico de columnas de destilación con mezclas azeotrópicas heterogéneas ternarias. I. Cálculo del reflujo mínimo
    (2013-11-07) Sánchez-Correa, César Augusto; Rodríguez, Gerardo; Gómez-García, Miguel Ángel
    Useful numerical tools to calculate the minimum reflux for infinite towers with heterogeneous azeotropic ternary mixtures are presented. For this, two geometrical elements are involved: the pinch point branches (PPB) and the structure defined by the binodal and the vapor line. The proposed conceptual design methodology integrates those two elements with the distillation borders at total reflux. The solution of the minimum reflux problem (MPR) for two mixtures of industrial interest (the dehydrations of acetic acid using n-amilacetate and ethanol using benzene) demonstrates the usefulness of the proposed methodology. For the analyzed mixtures under sharp separations the structure of the distillation lines at minimum reflux satisfies the regularities observed in homogeneous systems.