Simulation of Mononitrotoluene Isomers Distillation Unit

Mononitrotoluene isomers are important intermediate products which are produced as a mixture in the nitration of toluene. Distillation is one of the most effective methods for separation of mononitrotoluene isomers. In this paper, at the first, the properties of mononitrotoluene isomers and their different separation methods have been reviewed. Then, a semi-batch distillation unit for separation of mononitrotoluene isomers has been simulated by Hysys software. The results show a good agreement between this simulation and the previous practical data. In addition, a continuous distillation unit has been designed for high capacity toluene nitration units. In this unit, variation of temperature, pressure and flow rates have been investigated. The results show that the designed unit can separate the feed to 97% and 99.5% purity for ortho and para isomers, simultaneously.