Reactive Distillation in a Dividing Wall Column:  Rate-Based Modeling and Simulation

Abstract

In this paper, a novel rate-based description of nonreactive and reactive dividing wall columns is presented. These highly integrated units promise advantages in the context of process intensification. Until now, published studies have been focused on the nonreactive columns, based on equilibrium stage models, whereas the modeling of both dividing wall columns and reactive dividing wall columns, using the rate-based approach, has not been done yet. In the presented model, special attention is given to phenomena that have not been considered in previous publications (e.g., heat transfer through the dividing wall). The model has been applied to a nonreactive, ternary alcohol mixture and successfully validated. The transesterification of carbonates has been identified as an interesting system for the reactive dividing wall column. This reaction system is equilibrium limited and characterized by high conversion, yet low selectivity. Initial simulation studies demonstrate that the selectivity can be significantly increased by means of the reactive dividing wall column. Besides, this highly integrated unit enables a more efficient separation of products and nonconverted reactants, resulting in a reduction in the separation unit number.

Reactive DWC leading the way to FAME and fortune

“…The integrated RD process was designed according to previously reported process synthesis methods for reactive separations [44,38,36]. Rigorous simulations embedding experimental results were performed using Aspen Plus [1,2].…”

“…Remarkably, DWC is the only known large scale process intensification example where both capital and operating costs can be vastly reduced, with the additional benefit of reducing the required installation space by up to 40% [8,3]. Moreover, DWC is not limited to ternary separations only but it can be used also in extractive distillation [6], azeotropic separations [32], and reactive distillation [36,17,26,33]. DWC is considered a major breakthrough in distillation, as it brings significant reduction in CapEx and OpEx -up to 30-40% [19,8].…”

Reactive Distillation for Multiple-Reaction Systems: Optimisation Study Using an Evolutionary Algorithm

“…However, no experimental investigation of RD process was reported to validate the applied process model. The work of Mueller and Kenig (2007) is also restricted to a purely theoretical analysis. They designed a reactive divided-wall column for the synthesis of DEC by applying the heterogeneous catalyst dipotassium carbonate coated on polyethylene glycol.…”

Experimental study on pressure drops in a dividing wall distillation column

“…They found good agreement between the theoretical studies and the experimental results, concluding that it is Other works regarding simulations of the dividing wall distillation columns have been reported using a stage model based on mass transfer equations. For instance, Muller and Kening [15] have simulated the dividing wall distillation column considering reactive and non-reactive cases, and they found that the composition and temperature profiles showed good agreement with those measured in a DWDC.…”