Mathematical Analysis of Discontinuous Rectification Columns at Pilot Scale Based on the Continuous Stable States Concept and MESH Equations

Mathematical analysis and simulation of a discontinuous rectification column was performed using an operational strategy during the start-up before reaching pseudo-stable state in operation. The mathematical model formulated focusing on equilibrium (ES) implementing MESH equations (M: Mass balance, E: Equilibrium thermodynamics, S: Stoichiometry relations, H: Enthalpy or heat balance) to provide solutions Thomas method Wang-Henke algorithms internally coupled Fourth Order Runge-Kutta method. results were validated with experimental data from distillation at pilot scale ethanol-water system behavior described by UNIQUAC Functional-group Activity Coefficients (UNIFAC) Predictive Soave-Redlich-Kwong (PSRK) thermodynamic models global error 1.84%. molar ethanol concentrations presented deviations predictions 1.51% 0.02%, mean 0.48%. A 0.055% obtained for temperature profile column, thus demonstrating effectiveness solution its convergence capacity. based made it possible describe variables all stages column. Operation total reflux avoids wasting product allows stabilization variables, such as composition.