A Simple Way for Implementing Extraction Columns of Infinite Height in Flowsheet Simulators

A surrogate model to implement an extraction column of infinite height in process simulation software is presented. The model consists of three decanters and a few specifications which are easy to implement in commercial process simulators. Using the model, the minimum solvent flow rate and the limiting product compositions are determined. In an example, the surrogate model for the extraction column is combined with standard unit operation models for describing an extraction process with a distillative solvent recycle.