Separation Of2-Picoline/2-Ethanolpyridine By Batch Distillation

2-ethanolpyridine is an important raw material in chemical industry and mainlyused in synthesis of orgnic intermediates in fine chemicals. Meanwhile, it is widelyused in polymer materials, surfactants, pharmaceuticals and pesticides areas. Thisarticle studies the vapor-liquid equilibrium and the batch vacuum distillationprocesses of2-picoline/2-ethanolpyridine mixture by experiments ans simulations.First the experimental apparatus for2-picoline/2-ethanolpyridine vapor-liquidequilibrium is designed, and the vapor-liquid equilibrium data is determinedexperimentally for the first time. This paper uses UNIFAC group contribution methodto define2-ethanolpyridine in ChemCAD software and then use it in thevapor-liquid equilibrium of the two. The vapor-liquid equilibrium are simulated byUNIFAC, NRTL, Wilson three thermodynamic model under reduced pressure.Through the comparison of experimental data and simulation data, we can get that2-ethanolpyridine defined by UNIFAC group contribution method is reliable. Thesimulation data getted by UNIFAC thermodynamic model is very closed to theexperimental data, and therefore it is more appropriate to choose UNIFAC model forsimulation Finally batch vacuum distillation is proposed to separate2-picoline/2-ethanolpyridine mixture.Feeds of different composition are separated by batch vacuum distillation. Thenumber of theoretical plates of the column used in experiment is32and the refluxratio is1. Experimental results show that when the pressure is1325Pa and the massfraction of2-picoline in the feed is0.9, the mass fraction of2-ethanolpyridine massfraction in the bottom product is up to99.50%and2-picoline and2-ethanolpyridineare separated best.Feed of different composition are well separated using the experimental apparatusin this article. Within a certain range of reduced pressure, the content of2-ethanolpyridine in the bottom product decreases with the increase of top pressure.However, the change is small and the pressure has little effect on the vacuumdistillation process. The batch vacuum distillation process is simulated by ASPEN plus software andthe simulation results are in good agreement with the experimental data.