Study On Physical Properties And Phase Equilibria For The Systems Of N-Formylmorpholine

N-Formylmorpholine (NFM) is widely used in the recovery of aromatic hydrocarbons as a solvent for its good selectivity and heat stability. In order to design or improve these processes, it is extremely important to determine the physical properties and phase equilibrium data of NFM containing systems.Experiment liquid densities and viscosities of pure compound and their mixtures are needed for the design of chemical processes in heat and mass transfers or fluid mechanics. Densities and viscosities of the ternary systems of benzene+NFM,toluene +NFM,o-xylene+NFM,m-xylene+NFM and p-xylene+NFM (298.15～353.15) K were determined under atmospheric pressure using a vibrating U-shaped sample tube densimeter (model DA-505U) and a Ubbelohde suspended-level viscometer respectively. Density data were used in determination of excess molar volume and viscosity data were used to calculate deviation of viscosity. The excess molar volume and deviation of viscosity were fitted by the Redlich-Kister equation.Equilibrium data is the basis for the design and computation of separating processes, such as distillation, absorption, extraction and crystallization. An abundance of experimental data is needed for an accurate design of separation processes and facilities.Isobaric vapor-liquid equilibrium (VLE) data for benzene+NFM,toluene+NFM,o-xylene+NFM,m-xylene+NFM and p-xylene+NFM were measured at 101.33 kPa with an improved Rose equilibria cell. Wilson and NRTL equations were used to correlate the VLE data through the nonlinear least square method.Then the VLE data of benzene-toluene-NFM ternary system at 101.33kPa were measured and compared with the data predicted by Wilson model from the VLE data of the binary systems of benzene-NFM, toluene-NFM and benzene-toluene., and the deviations are acceptable.