Conceptual Design of Distillation-Pervaporation in Single Unit Columns Using Residue Curve Map Methodology

摘要

A short-cut design method based on Residue Curve Maps (RCMs) is applied to the conceptual design of Distillation-Pervaporation in a Single Unit (DPSU) columns. Unlike to a conventional hybrid distillation-pervaporation column, in a DPSU system the pervaporation module is located inside the column. The distillation and pervaporation mechanisms are fully coupled, allowing overcoming azeotropic conditions of non-ideal mixtures inside the distillation column. The simplified design method is applied to four non-ideal mixtures with different Serafimov's topological classification: acetone-isopropanol-water (1.0-2), ethyl acetate-ethanol-methanol (2.0-2b), acetone-methyl acetate-methanol (3.1-2) and acetone-methanol-chloroform (3.1-4). The results show that it is possible to achieve a feasible separation through a DPSU column with product compositions split by distillation boundaries. Besides, the regions of a feasible separation with a DPSU column are identified. Thermodynamic limitations for a DPSU column are observed when the azeotropes generate isovolatility lines, producing different separation paths for a specified membrane selectivity. DPSU columns promise to strongly reduce the number of units and associated energy consumption in distillation trains for separating complex mixtures.