Shortcut Design Method For Reactive Dividing Wall Column

Distillation is one of the most widely used unit operations in the petrochemical and otherindustrial processes, but it has the disadvantages of higher energy consumption and lowerthermodynamic efficiency. With the energy crisis and environmental requirements becomingincreasingly prominent, the development of process intensification technology draws moreand more attention. Based on the conventional distillation, the new process intensificationtechnology, such as reactive distillation, azeotropic distillation, extractive distillation anddividing wall column are advanced. Dividing Wall Column (DWC), as a special structure ofthe fully thermal coupling, can complete the separation of three components in one towershell. It has the advantages of lower capital cost and energy consumption. The reactivedistillation process can improve the reacting conversion by integrating the reaction with theseparation.Firstly, the principles and the calculation procedure of the minimum vapor flow methodare illustrated. The method, which is based only on Underwood equations, is rather simplistic.The energy-consumption under different operations in each section is analyzed through theuse of a minimum vapour fow, or so called Vmindiagram method. The vapor flow of thecolumn can be seen directly by the Vmindiagram.Secondly, minimum vapor flow method is applied to the shortcut design of the dividingwall column represented by the Petlyuk configuration. The Underwood equations applied tothe prefractionator and the coupled colums are presented. Taking the alkane mixturesseparation as an example, the minimum vapr flow method and the Vmindiagram are used forthe design of the dividing wall column. The results show good agreement with other methods.Thirdly, the application of the minimum vapor flow method to the reactive distillaioncolumn is discussed. The key to this method is to introduce a new varable related to the reaction and derive an improved Underwood equation, which can be applied to the reacivedistillation column. Taking the reactive distillation of the syntheis of MTBE as an example,the results show that the parameters calculated through this method are reliable.Finally, based on the study of the dividing wall column and reacive distillation column,the minimum vapor flow method is applied to the reactive dividing wall column. The energyconsumed in different operation regions is discussed. Taking the syntheis of MTBE as anexample, the results show that the minimum method and the Vmindiagram can be extended tothe reactive dividing wall column.