Programação em VBA para a modelagem do equilíbrio sólido líquido de misturas multicomponentes a partir dos modelos Wilson, NRTL, UNIQUAC e UNIFAC

Abstract

Oil deodorization distillate is a mixture of components of interest to various industrial sectors. Among the operations studied for the extraction and purification of these compounds are methanolysis and/or glycerolysis, molecular distillation, supercritical fluid extraction, adsorption, applied individually or together. A simpler alternative to one or more of these steps is fractional dissolution. It requires knowledge of the solubility of the components at different solvents and temperatures. The use of thermodynamic models adds to this technique a way to describe this behavior from a small amount of experimental data. Given this context, the present work aimed to develop two computer programs in VBA language, one for the adjustment of the parameters of the Wilson, NRTL, UNIQUAC models, and the other for the adjustment of the group interaction values of the UNIFAC model aiming the description of the solid-liquid equilibrium of multicomponent mixtures in which the solid phase can be considered ideal. Nonlinear GRG and Evolutionary algorithms of the Solver tool (Microsoft Excel®) were used to minimize the objective function. The programs make it possible to obtain activity coefficients, solubilization temperatures and deviations between experimental and calculated values for multicomponent systems. The deviations found were satisfactory, with the highest values being 3.12%, 10.87% and 3.42% for binary, ternary and quaternary systems, respectively. From the above, it can be concluded that both programs are very effective in achieving the objectives for which they were developed.