Identification and analysis of possible splits for azeotropic mixtures. 2. Method for simple columns

Conceptual Design of Azeotropic Distillation Processes

“…Recently, Petlyuk et al [79,88] presented a computational simple method for the identification and analysis of possible splits and product regions for sharp splits. The method is based on an analysis of the pinch branch terminals and can also be used for the synthesis of distillation sequences.…”

Extractive distillation: recent advances in operation strategies

“…noniterative method for finding the possible splits at finite reflux ratio of azeotropic distillation based on the identification of the common terminal points of pinch branches in each column section (Petlyuk et al 2011(Petlyuk et al , 2012. Its extension to extractive distillation is in preparation.…”

Using the Method of Infinitely Sharp Splits for the Optimal Design of Extractive Distillation Units. 1. Ternary Mixtures

“…To eliminate the shortcomings of the above-mentioned design methods, a new approach for optimal conceptual design of extractive distillation columns/units was developed in this work. This design approach is based on the infinitely sharp split (ISS) method, − which considers that each section of extractive distillation column has an infinite height and that it allows to achieve a sharp split for at least one component of the mixture; that is, this component is only present at one end of this section as depicted in Figure of our previous paper . The main features of the ISS method can be summarized in the following points: The product points for all column sections and for a mixture with any number of components are located on the boundary elements of the composition simplex, that is, vertices, edges, faces, and so forth.…”

“…The molar fraction change of the absent components on adjacent trays is infinitesimal. Therefore, it can be considered that the molar fractions of all other components on adjacent trays in the vicinity of the product point in the respective section remain constant (i.e., x i m +1 = x i m , where m is the tray number and i denotes the present component). In each section, the feasibility of the respective split is fulfilled for a given inequality of phase equilibrium coefficients of the present and absent components and for specific material balance equations in the vicinity of the product point of this section. − In each column section, constant molar flow rates of internal liquid and vapor streams are assumed, and the composition profile (section trajectory) is determined by the tray-to-tray calculation method . The section trajectory moves toward the respective stable node pinch. …”