Optimal Synthesis of Multicomponent Zeotropic Distillation Processes. 1. Preprocessing Phase and Rigorous Optimization for a Single Unit

Abstract

Separations performed by distillation involve large operation costs due to either large heat loads or large amounts of solvent used in azeotropic mixtures. Thermodynamic aspects helpfully lead the process synthesis to energetically efficient designs. The reversible distillation sequence model (RDSM) is employed in this work as a theoretical and ideal thermodynamic model. The aim of the paper is to present an automatic methodology for the synthesis of simple distillation columns that approximate reversible conditions. A preprocessing phase is considered where proper values to initialize and bound the variables involved in the rigorous model are calculated by successively solving auxiliary optimization models. In all cases studied, the solutions obtained are very similar to those in the so-called reversible separation. This fact is used as a test criterion for global optimality of the solutions.

Rigorous design of distillation columns using surrogate models based on Kriging interpolation

“…Barttfeld et al, performed a comparative study of MINLP and GDP formulations concluding that GDP formulations are numerically more robust and require less solution time, but are more sensitive to initial values and bounds. To provide a good feasible initial design and good initial values for the rigorous optimization, Barttfeld and Aguirre proposed a reversible distillation model that involves minimum reflux as well as minimum entropy generation; but this approach is limited to the so called “preferred separation.”…”

Using feasible regions to design and optimize reactive distillation columns with ideal VLE

“…5. Similar initialization schemes have been shown to improve the convergence of full‐column models 21 …”

Logic hybrid simulation-optimization algorithm for distillation design

“…Even though, GDP seems to be more reliable than MINLP models both require good initial values and bounds to converge. Barttfeld & Aguirre (2002, 2003, propose to use a reversible distillation model that involves the minimum reflux conditions as well as minimum entropy production to provide a feasible initial design, and good initial values for the rigorous optimization. Their method is mainly limited by the drawbacks of this so-called "preferred separation", because, for azeotropic mixtures, usually nonsharp splits are generated.…”