Modeling and simulation of diluent recovery unit in PUREX solvent regeneration system

The presented work details the modeling and simulation of distillation column for the separation of tributyl phosphate (TBP) and normal paraffin hydrocarbon (NPH) which is an integral unit in the PUREX solvent regeneration system. The vapor liquid equilibrium data of TBP + NPH system at 5.5 torr and 7.5 torr were experimentally generated using an ebulliometer and the data were subjected to thermodynamic consistency test using Herington's method. The experimental VLE data were correlated using Wilson and non random two-liquid (NRTL) models and the binary interaction parameters regressed from the data are reported. The distillation column simulation was carried out using an algorithm involving separate solver/corrector loops for the MESH variables and the NRTL model was used for predicting the vapor liquid equilibrium of TBP-NPH system. Validity of the developed code was tested by comparing the simulation outputs with the experimental results from PUREX solvent regeneration plant.