Industrial & Engineering Chemistry Research, Vol.53, No.48, 18526-18538, 2014
Selectivity Engineering with Simple and Complex Hybrid Reactive Distillation Columns
A new synthesis and design method is developed for simple and complex hybrid reactive distillation columns, to achieve desired selectivity in case of multireaction schemes involving multicomponent mixtures wherein, reactant is a saddle in the corresponding residue curve map. The developed methodology makes use of attainable region approach as well as combined graphical-simulation approach. We determine the surface of reactive stage compositions (SRSC) such that if the reaction takes place at any of the compositions that belongs to SRSC then the desired selectivity is ensured. Design guidelines have been formulated based on the number of compositions of the reactive species that appear in the equation of the SRSC, to identify appropriate hybrid RD configurations for the reaction scheme of interest. The method is illustrated using an industrially relevant example of intramolecular aldol condensation of cyclohexanone to achieve the desired selectivity toward 2-cyclohexylidene cyclohexanone. The results provide good initialization for rigorous simulation. The algorithm presented here can be applied to any number of components and can be directly applied to even multiazeotropic systems as well but is restricted to single reactant (i.e., single feed configurations) multireaction schemes with multiple products undergoing side reactions.