New feature in ProSimPlus

A new dimensioning method for divided wall columns has been implemented in ProSimPlus.

Divided Wall Columns (DWC) are an interesting innovation to improve the energy efficiency of separative processes by distillation. However, they are still too little used in the industry due to a lack of experience when sizing Divided Wall Columns. The simulation of this type of equipment has long been possible in a process simulator such as ProSimPlus by splitting the divided wall column into 2 (or 4) interconnected “sub-columns”. But this requires a correct initialization of the intermediate streams and knowledge of the parameters for each of the “sub-columns” (number of theoretical stages). Only a few methods have so far been available for this and none have been implemented in a process simulator.

Relying on the work conducted at the Laboratoire de Génie Chimique (LGC: www.lgc.cnrs.fr) by Professor Michel Meyer’s team, a new dimensioning method has been implemented in ProSimPlus. This includes a short-cut method for simple distillation, where it is now possible to determine the main parameters of each of the 2 (or 4) columns in order to obtain the desired separation. The new SHORTCUT DWC unit operation allows you to size a distillation column with a separation wall, with a feed and three products: the distillate, the waste, and the intermediate sidestream. Specifying the recovery rate of the three key-compounds for each outlet stream and some operating constraints allows the unit operation to calculate a sizing by theoretical stages, and the initializations for the intermediate streams required for a rigorous calculation.

The rigorous simulation (plate by plate) of such columns with partition is then easy. The methods implemented in ProSimPlus have been experimentally validated using the pilot installation of the LGC.