The Study of the Effects of Solvent (NMP) Parameters on C4-cut Separation Processes with Extractive Distillation (Technical note)

1,3-Butadiene, BD is produced from C4-cut by extractive distillation. The separation of 1,3-Butadiene from C4-cut is not possible through the conventional distillation processes, because several mixtures have consisted of close boiling points constituents and make azeotrope. The BASF extraction distillation process in BD unit of Jam and Amirkabir Petrochemical Company improves the relative volatilities of components by addition of a high boiling point solvent (namely N- methylpyrrolidone, 8.3%wt H2O). With respect to high mass ratio of total solvent to feed, the solvent has significant role in separation. In this study, extractive distillation system was simulated with the HYSYS3.1 software to investigate the effect of the temperature and as well as that of feed entry stage of the solvent on the separation. It was found that; the reduction of solvent temperature had no considerable effect on products’ specifications, but rather, it could minimize the solvent rate.