The separation of liquid mixture into their several components is one of the major operations in chemical/petroleum industries and distillation is perhaps the most widely used method of achieving it. Binary distillation is a unit operation for separating two or more components in a mixture by distributing them between a vapour and liquid phase based on the difference in the volatility of the components. Three main methods of binary distillation are used in practice. These are differential distillation, flash or equilibrium distillation and rectification. All rely on the basic fact that the vapour is always richer in the more volatile component than the liquid from which it is formed. In rectification, which is the most important method, part of the vapour is condensed and returned as liquid to the still. In the other two methods, the entire vapour is either removed or it is condensed as a product. The essential merit of rectification is that it enables a vapour to be obtained that is substantially richer in the more volatile component than the liquid left in the still. This is achieved by an arrangement known as a fractionating column, which enables the successive vaporization and condensation to be accomplished in one unit. The theory and equations and correlations for determining
important parameters in binary distillation is well discussed in many chemical engineering text books (Coulson and Richardson 1983; Hengstebeck 1963; Kern 1990; and Treybal 1981). Two methods are employed in calculating the design parameters in binary distillation. They are the Lewis-Sorrel and McCabe-Thiele methods. The former method can also be used for calculations in multicomponent distillation to determine the number of plates and is the basis of modern computerised methods. The algorithm for implementing the method is well documented (Himmeblau 1974; and McCabe et al. 1993). It shows that the stage-wise calculations use equilibrium data and mass balance calculations, which are represented by the operating line equations. Modern engineering practice is becoming largely dependent on computer and information technology. Computer Aided Design (CAD) is therefore used in the design, maintenance and operations of the plants (Oguntoyinbo 1993; Rooney and Steadman 1980; and Westerberg et al. 1979). Plants are generally made up of unit operation equipment, which are similar in functions and differ only in their duty or throughput. A design approach that is yielding positive results is the independent creation of modules, which can be incorporated into large
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systems of flowsheeting (Onifade 2000; Onifade 2001a). The objective of this work is to create a similar module for a binary distillation column.