Thermodynamic Topological Analysis of Extractive Distillation of Maximum Boiling Azeotropes

Abstract

-This paper provides a feasibility study of azeotropic mixture separation based on a topological analysis combining thermodynamic knowledge of residue curve maps, univolatility and unidistribution curves, and extractive profiles. Thermodynamic topological features related to process operations for typical ternary diagram classes 1.0-2 are, for the first time, discussed. Separating acetone/chloroform is presented as an illustrative example; different entrainers are investigated: several heavy ones, a light one, and water, covering the Serafimov classes 1.0-2, 1.0-1a and 3.1-4, respectively. The general feasibility criterion that was previously established for ternary mixtures including only one azeotrope (1.0-1a or 1.0-2) is now, for the first time, extended to that including three azeotropes (class 3.1-4).

Review of extractive distillation. Process design, operation, optimization and control

“…5c-f) and the determination of the location of the extractive stable node enabling a feasible extractive distillation process. Similar figures are found in the literature for the (0.0-1) extractive separation class (low˛mixture separation with a heavy entrainer) (Rodríguez-Donis et al, 2009b) and for the (1.0-2) extractive separation class (minT azeotrope separation with a light entrainer) (Gerbaud and Rodriguez-donis, 2014;Shen et al, 2015bShen et al, , 2016. Following these opening works, a systematic exploration of the feasible separation of minimum or maximum boiling azeotropes with either heavy, intermediate or light entrainers was carried out for the batch extractive distillation process.…”

“…It was falsely assumed for decades that the unique feasibility rule for the extractive distillation process was the (1.0-1a) class separation, corresponding to the homogeneous extractive distillation of a minT azeotropic mixture with a heavy entrainer or of a maxT azeotropic mixture with a light entrainer (1.0-1a occurrence 21.6% among azeotropic diagrams). But some twenty works published between 1990 and 2013 explored which ternary diagrams would be suited for extractive distillation (Laroche et al, 1991(Laroche et al, , 1992a; Wahnschafft and Westerberg, 1993; Knapp and Doherty, 1994;Petlyuk et al, 1999Petlyuk et al, , 2015Serafimov et al, 2008;Kotai and Lang, 2005;Kotai et al, 2007;Lang, 1992;Lang et al, 1994Lang et al, , 1995Lang et al, , 1999Lang et al, , 2000aLelkes et al, 1998aLelkes et al, ,b,c, 2002Lelkes et al, , 2003aModla et al, 2001Modla et al, , 2003Rev et al, 2003;Stéger et al, 2005Stéger et al, , 2006Varga et al, 2006a,b) until the general feasibility rules discussed in the previous section were enounced (Rodríguez-Donis et al, 2009a,b, 2010, 2012aGerbaud and Rodriguez-donis, 2014;Shen et al, , 2015bShen et al, , 2016 For homogeneous extractive distillation with an entrainer forming no new azeotrope, the feasible diagrams belong to the following classes: (1.0-1a) (separation of minT with E heavy or maxT with E light, occurrence 21.6% among azeotropic diagrams), (1.0-2) (separation of maxT with E heavy or minT with E light, occurrence 8.5%), (1.0-1b) (minT with E light or maxT with E heavy, occurrence 0.4%), and (0.0-1) (low mixture with all type of E, see occurrences in Reshetov and Kravchenko (2007). Besides, when the entrainer forms a new azeotrope, ternary diagrams classes (2.0-1) (occurrence 0.6%), (2.0-2a) (occurrence 0.4%), (2.0-2b) (occurrence 21.0%) and (2.0-2c) (occurrence 0.9%) ...…”

Evaluation of a New Multimodal Optimization Algorithm in Fluid Phase Equilibrium Problems

“…The term azeotrope refers to a thermodynamic condition where a boiling liquid produces a vapor phase with the same composition. The existence of azeotropes can occasionally cause problems in the separation of the mixture by distillation (see Shen, Benyounes, and Song, 2015).…”

Improved Design of Maximum-Boiling Phenol/Cyclohexanone Separation with Experimentally Verified Vapor–Liquid Equilibrium Behaviors

“…A recent review paper on extractive distillation also supported the above statement by surveying extractive distillation papers in the open literature and found out that the mixtures to be separated are rarely maximum-boiling azeotropes. Perhaps the most studied maximum-boiling system was for acetone and chloroform separation via either pressure-swing distillation or extractive distillation systems. − Other studied systems include ethylenediamine and water separation, − methanol and trimethylsilane separation, , acetic acid and N , N -dimethylacetamine separation, and some esters (methyl acetate, ethyl acetate, or vinyl acetate) and chloroform separation. − Another particular system is for the n -heptane and isobutanol separation, which exhibited minimum- and maximum-boiling azeotropes at different operating pressures …”