Resumen

MENDOZA, D.F.  y  RIASCOS, C.A.M.. Methodology for design, analysis and thermodynamic optimization of distillation columns with internal heat exchangers. Rev. Mex. Ing. Quím [online]. 2015, vol.14, n.2, pp.523-542. ISSN 1665-2738.

A methodology for design, analysis and thermodynamic optimization of distillation columns with internal heat exchangers is presented. The method employs irreversible thermodynamics and reversible distillation trajectories to map, classify and assess process irreversibilities, it employs a multilevel constrained optimization strategy to determine the heat load distribution that minimizes the entropy production in the column. The proposed methodology is an extension of previous works (Mendoza and Riascos, 2010 and 2011), it includes calculation of reversible distillation trajectories as strategy to define limits for design variables that must be estimated in the optimization, and for attainable thermodynamic efficiency. The ethanol dehydration process by extractive distillation using ethylene glycol as entrainer is used to illustrate the methodology, due to the difference between components boiling points and the high no ideality, this system is an interesting challenge for developing of design and optimization strategies. The results show that optimized distillation columns with sequential heat exchangers reduce the entropy generation 14% (solvent recovering column) and 16% (extractive column) compared with its optimized adiabatic ones. Furthermore, the proposed methodology showed to be robust, without convergence problems during the optimization, in that way, it allows to generate a suggestion for the optimal design and operation of the columns. The results show good concordance with the ones obtained with Aspen Plus^TM employing radfrac model.

Palabras llave : optimization; extractive distillation; diabatic columns; entropy production; reversible distillation; irreversible thermodynamics.

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