Computation of residue curves maps using a simple finite difference method

Abstract

The most common methodology for obtaining residue curve maps is through a system of differential equatioin, commoly solved These maps are obtained through a system of differential equations, which is commonly solved in two steps, namely a liquid-vapor equilibrium and a system of differential equations.  The goal of this work is to present a new methodology for the elaboration of residual curve maps.differential equations. In this methodology, the bubble T is considered a differential equation and together with the Rayleigh equation, which is a system of differential equations that determines the residual composition of a liquid mixture to be distilled, are solved using the Finite Difference Method.  For this purpose, the new methodology will be applied to the ternary systems ethyl ether / methanol / 1-butanol and ethanol / 2-methyl 2-propanol / methylcyclohexane. The fugacity coefficient of the vapor phase was calculated using the Virial equation (truncated in the second coefficient), and the activity coefficient of the liquid phase, using the NRTL, UNIQUAC and UNIFAC models. The results showed the potential of the new methodology compared to conventional approaches.