Vapor-liquid Equilibrium Research Of C₄-NMP Binary System And C₄-NMP-H₂O Ternary System

The reaction of oxidative dehydrogenation of n-butene to butadiene mainly produces C4hydrocarbons which should be purified to get pure1,3-butadiene. The extractive distillation method should be applied to separate1,3-butadiene from C4hydrocarbons since they have rather similar boiling points. Research of vapor-liquid equilibrium as a basic work for separation process plays an important role in the design of unit operations, optimization of process, evaluation of production plants and so on.Experimental data of C4-NMP binary system and C4-NMP-H2O ternary system were measured under343.15K,363.15K,383.15K,403.15K and473.15K. C4gases contain n-butane, isobutene, n-butene, isobutene and1,3-butadiene. Experimental data have been correlated by NRTL Equation which is suitable for partially miscible system. According to experimental data, NRTL Equation parameters were optimized by non-linear least square method.The results showed, for binary system, relative error of experimental data and calculation data was no more than3%other than the relative error of n-butane, isobutene, n-butene, isobutene systems under473.15K within20%. Especially, relative error of the1,3-butadiene-NMP binary system was no more than3%. For ternary system, relative error of five systems was no more than5%, and relative error of1,3-butadiene-NMP-H2O ternary system was within2%. It was helpful for the technology design and related research.