Dividing wall columns for heterogeneous azeotropic distillation

• Implementing heterogeneous azeotropic distillation in a dividing wall column.
• Two possibilities: distillation column with side-rectifier and Petlyuk column.
• Using isobutyl-acetate (IBA) as entrainer for the separation of water–acetic acid.
• Only with Petlyuk arrangement, we can achieve energy savings of about 20%.

The aim of this work is to implement heterogeneous azeotropic distillation schemes in a dividing wall column (DWC) for a feed mixture of water (W), acetic acid (HAC) and an organic component (X). The original design makes use of X to act as an entrainer to facilitate the separation of water and HAC, and we also propose a DWC design based on this idea. This DWC design reduces the capital cost, but the energy usage is almost unchanged. To achieve energy savings and further reductions in capital costs, we need to use a Petlyuk DWC. We introduce isobutyl acetate (IBA) as an additional entrainer for the Petlyuk DWC, and achieve energy savings of about 20%.

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