Computation of residue curves using mathematica® and MATLAB®

The Author presents a teaching technique used successfully in an undergraduate course to seniors at The National Institute of Applied Sciences and Technology (INSAT) in Tunis, Tunisia. The present paper details the computational aspects needed to obtain residue curves (RCs) for a binary and various ternary systems using Mathematica® and MATLAB®, which are taught in Tunisia. The first mixture studied is composed of ethanol - isopropanol. A ternary ideal mixture composed of benzene - toluene - p-xylene is treated next. A non- ideal ternary mixture (ethanol - water - ethylene glycol), using the Wilson model to predict liquid-phase activity coefficients, is also presented. Finally, a case, where both high pressure effect and deviation from ideal behavior in the liquid phase must be considered, using the Soave - Redlich - Kwong (SRK) equation of state (EOS) and the Wilson model, respectively, is studied. This final mixture contains acetone, chloroform and methanol. All problems are solved using the built-in Mathematica® and MATLAB® commands NDSolve and ode15s. The author concludes with insight to using residue curves (RCs) in order to teach distillation with the help of computer software such as Mathematica® and MATLAB®.