VLE Thermodynamic modeling in Butadiene Unit with NMP Solvent
Advancing the chemical engineering fundamentals
Thermodynamics (T2-1P)
Keywords: Extractive Distillation, Vapour-Liquid Equilibria, Butadiene, NMP
The aim of this study is thermodynamic modeling of butadiene unit.C4 mixture are usually separated by extractive distillation. In the present work 1,3-butadiene is separated by N-methylpyrrolidone (NMP) as solvent to reach 98% purity.C4 mixture produced in Ethylene unit as a byproduct of cracking process. Separation of 1,3- butadiene from the C4 cut is not possible by conventional distillation due to several azeotrope mixtures and very close boiling point of the components. Through extractive distillation process, it is possible to modify relative volatilities of components by addition of a high boiling point solvent. In this study modeling of vapour-liquid equilibria of the system have been performed by equation of state and activity models such as NRTL, WILSON and UNIQUAC. It was found that activity model is more accurate for prediction of the liquid behaviour of hydrocarbon and NMP system. The binary interaction coefficient of the components (hydrocarbon – NMP system and water – hydrocarbon system) are tuned by different methods by using VLE data from the plant. It was found that NRTL equation is able to predict the experimental data with the least error. Simulation of extractive distillation columns of the unit have been performed by optimized NRTL model.
Presented Monday 17, 13:30 to 15:00, in session Thermodynamics (T2-1P).
