Reactive and non-reactive distillation sequences: Energy saving by process integration Ivo Müller, Eugeny Y. Kenig Chair of Fluid Separations, Dortmund University of Technology, 44227, Dortmund, Germany, email: e.kenig@bci.uni-dortmund.de; fax: +49 231 755-3035 Abstract In this work, the energy consumption for distillation sequences with different integration degree is investigated with the aim to identify the optimal configuration. For this investigation, a non-reactive system (ternary alcohol mixture) and a reactive system (transesterification of dimethylcarbonate) are chosen, and, for each system, several promising configurations with increasing integration degree are identified. Their analysis shows that the unit integration leads to significant savings in energy consumption and production costs for both non-reactive and reactive systems. Introduction Distillation represents a widely used, yet most energy intensive step in chemical and process industries. Since energy costs have permanently been increasing, an essential improvement of distillation performance has become more and more important. Therefore, in the last decades, significant effort has been undertaken towards optimisation of distillation units. Integration of different operations within a single unit represents an interesting approach to achieve significant energy savings. Compared to serial sequences of conventional distillation columns, the well-known dividing wall column (DWC) offers better thermodynamic efficiency, reduced energy consumption and costs [1]. Recently, this principle has also been applied to reactive distillation processes resulting in the co-called reactive dividing wall column (RDWC, see [2]). Both DWC and RDWC represent processes with a very high degree of integration. However, integration can sometimes be disadvantageous, as it may reduce the operating window. Therefore, less integrated processes still remain an alternative and should be considered for process design. In this work, the energy consumption for distillation sequences with different integration degree is investigated with the aim to identify the optimal configuration. Estimation of feasible column set-ups In order to investigate different configurations, their set-up and operating parameters have to be determined. For the DWC and RDWC, this is especially difficult regarding the large number of required design parameters. In addition to conventional column variables (e.g., reflux ratio, distillate stream), further parameters, e.g., location and height of the dividing wall, distribution of liquid above the dividing wall (also called liquid ratio), have to be determined. To address this issue, Triantafyllou and Smith [3]