Obtaining distillation and residue curves for nonideal ternary systems.

Abstract

The aim of this work is the creation of an EXCEL program that draws distillation and residue curves of homogeneous ternary mixtures, where the user can select the components to study and work pressure. The industry is based on the best utility and use of raw materials and resources, which means finding an optimal design, often this takes a lot of complexity to find the most efficient use. The separation of the different compounds in a multicomponent blend can be complicated when the boiling point difference is very small, which does not allow a simple distillation or also by the presence of azeotropes in the mixture. In fact the first thing that has to be known for designing a separation process, is to know if the mixture forms an azeotrope or not. This work may be useful in such cases and detect the possible formation of azeotropes and its composition in a ternary system (residue curves), as well as to define the distillation curves and distillation regions which will conditionate the strategy of the separation process. There are several commercial simulation softwares that allow to build residue curve maps (Aspen), however, these programs are expensive, and for some purposes, e.g. educational ones, it might be an interesting option to possess a home-made program. This work also pretends to give the user more options for the design of residue curve maps. This program called RCM Designer (residue curve map) will be tested for several mixtures and some of the results will be compared to the ones obtained with ASPEN simulator in order to assert the validity of the results. During the development of the program we encountered a problem, finding an algorithm to build distillate lines was unsuccessful and RCM Designer cannot calculate the necessary points to build distillate lines, except for a few mixtures (an example will be discussed).