Heat pump assisted reactive and azeotropic distillations in dividing wall columns

• Heat pumps are applied to reactive and azeotropic dividing wall columns.
• Vapor from top of the dividing wall column is recompressed to drive side reboiler.
• The novel processes show their economic advantages as payback period increases.
• The thermodynamic efficiency is related to inefficient generation of electricity.
• The CO2 emissions can be reduced by the novel processes.

Process intensification is aimed at reducing energy consumption and capital investment, as well as achieving environmental benefits by integrating different processes. Heat pump and dividing wall column distillations are two representative examples of such design technology. In this study, the performance of heat pump assisted dividing wall column, a recent technology combining both heat pump and dividing wall column, is investigated for a reactive distillation system and a heterogeneous azeotropic distillation system. Vapor from top of the dividing wall column is recompressed and used to drive the side reboiler. Economic and thermodynamic efficiencies and the carbon dioxide emissions of the novel processes and the dividing wall column processes have been estimated. The results indicate that applying the heat pump technology to the dividing wall columns can achieve operating cost savings and also increase the installed capital cost, which means that companies who can afford higher investment should consider the heat pump assisted dividing wall columns for better return in the long run. Besides, heat pump assisted dividing wall columns are beneficial for cases where clean and highly effective electricity generation technologies are adopted.

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