The conceptual design and process intensification of the separation of ternary azeotropic mixture with heterogeneous characteristic

Abstract

A substantial amount of ternary azeotropic mixtures with heterogeneous properties are generated in the production processes of the pharmaceutical and fine chemicals industries. While the presence of heterogeneous features complicates the thermodynamic behavior of such mixtures, it also creates opportunities for separations using heterogeneous distillation. Thus, this study focuses on the conceptual design and process intensification for the separation of heterogeneous ternary azeotrope mixtures integrating decanter, distillation, and heat pump technology. Based on the characteristics of a mixture with a liquid-liquid partial miscibility region, the design procedure including conceptual design, multi-objective optimization, and heat pump-assisted intensification has been proposed. The separation of acetonitrile-cyclohexane-toluene is used to illustrate the capability of the proposed design procedure. The results demonstrated that the heat pump-assisted process including one decanter, one distillation column, and two stripper columns provides the best separation process, excelling in economic, environmental, and thermodynamic performance, whose TAC is 76.15% lower than the conventional heterogeneous distillation.