Study On 2-methylpyridine Dehydration By Azeotropic Distillation

2-Methylpyridine is a very important industrial reagent,which is widely used in field of chemical,material,pharmaceutical and so on,the dehydration is essential to get pure 2-methylpyridine product,but the vapor-liquid equilibrium parameters of 2-methylpyridine and water systems is rarely reported in detail,and the binary system is non-ideal under ordinary conditions of pressure,so it is impossible to separate by conventional distillation,the traditional purification methods of 2-methylpyridine in industrial production is adding alkali,which has a lot of defects,for example,it takes long operation time and has low production efficiency,in addition,it causes the serious environment pollution.Therefore,this article carried out research on azeotropic distillation to separate the specific system,and achieved satisfactory results.In this article,the 2-methylpyridine and water system binary vapor-liquid equilibrium data under ordinary conditions was measured through experiment,and the experimental data had examined by the Herington area method to test the thermodynamic consistency.Then the experimental data was regressed by the simulation software of Aspen Plus with NRTL,Wilson and UNIQUAC liquid activity coefficient equation,which is coincided with the model to great extent.Cyclohexane was chosen as the azeotropic agent in this article.The simulation of 2-methylpyridine azeotropic distillation was carried out by Aspen Plus.Then this article got optimal operation parameter by debugging with different azeotropic dosage agent,feed position and output quantity to separate specific composition material.The result showed that the purity of 2-methylpyridine and water can be achieved as 99.54 wt% and 99.97 wt%.At last,this article verified cyclohexane technology feasibility through batch distillation experiment and got the 99.8 wt% 2-methylpyridine.So cyclohexane is an ideal azeotropic agent.