The reactive dividing-wall column (RDWC) combines a reactor and a dividing-wall column (DWC) in a single column shell. Lately, various reaction systems have been proposed for the RDWC, but only little general knowledge has been published on the RDWC so far. The fundamental mechanisms of the RDWC are analyzed and a profound process understanding is deduced based on principal aspects of reactive distillation and the DWC. Fields of application and insights into the key factors for an energy-efficient operation are systematically derived. A semi-shortcut method is proposed to determine the minimum vapor demand of the RDWC and its energy-saving mechanism is explained. Thereby, process engineers can evaluate already during the process synthesis whether the RDWC is a promising option. Furthermore, they can quantify the energy savings quickly and get an understanding of the key factors for an energy-efficient column design and operation.

Reactive dividing wall columns (RDWC) are a special type of distillation column that allow for the targeted realization of chemical reactions and the separation into multiple product fractions in one shell. However, despite their huge economical and ecological potentials for certain fields of application, this innovative technology has not found its way into industrial production processes yet. The very limited availability of experimental research studies verifying the prediction capabilities of respective modeling concepts for this type of distillation column might be one decisive reason for that. Therefore, the present study puts its focus on the detailed comparison between experimental operation of RDWC and the corresponding simulation results for steady‐state. For the first time, the mentioned comparison is carried out for a chemical system with non‐negligible side reactions. It is shown that even for this highly complex system, the mathematical model is capable of predicting the column operation. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1036–1050, 2017

The implementation of a vertical dividing wall (DW) into a distillation column is a well-known concept which can result in considerable energy savings for the separation of multicomponent mixtures. It is commonly known that heat streams across the DW, which are present due to temperature differences between both sides, may either increase or decrease the energy demand for a certain separation task. However, no work has been published so far which explains the maximum influence on energy demand. This article derives the maximum extent to which the minimum energy demand for a given column design can change due to heat transfer across the DW. Additionally, it is illustrated how energy-efficient column operation can be assured even if the total amount of transferred heat is unknown. These results show that the phenomenon of heat transfer across the DW can be handled very well with a suitable control strategy.Within this work, an EQ model based on the well-known MESH equations is used. 24 For the solution of the model equations, the software Aspen Custom Modeler (ACM) by Aspen Technology, is applied. ACM is an equation-oriented simulation tool and is thus especially suited for the Figure 2. Material streams being used in Eqs. 1 and 2.

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The two main concepts for the modeling of distillation columns are the equilibrium-stage (EQ) and the nonequilibriumstage (NEQ). A model is presented which combines decisive features of both conventional concepts. Based on the idea of a reduced nonequilibrium-stage (RNEQ), this model can be used for the simulation of distillation columns with packings. In contrast to the conventional NEQ approach, this model neglects the influence of liquid side mass-transfer coefficients, which ultimately allows to come up with only one empirical equation describing the overall mass transfer. Thus, a considerable reduction in model complexity is reached, which allows for an efficient consideration of new experimental distillation results. Fitted to experimental data, the model is able to predict, how different pressures and chemical systems might affect the separation efficiency. By comparing calculation results with experimentally determined separation efficiencies for three different packing types, these valuable RNEQ qualities are illustrated. V C 2014 American Institute of Chemical Engineers AIChE J, 60: [3833][3834][3835][3836][3837][3838][3839][3840][3841][3842][3843][3844][3845][3846][3847] 2014