VISCOSITY AND DENSITY IN THE SYSTEM HEPTA N-TOLUENE - N,N-DIMETHYLFORMAMIDE BETWEEN 20 AND 35-DEGREES-C

The densities and viscosities of contacting phases are required for th e evaluation of data obtained from liquid-liquid mass-transfer experim ents in the partially miscible system heptane - toluene - DMF. For red ucing the experimental efforts, it is desirable to calculate these pro perties for a determined phase composition by means of predictive equa tions. Therefore new sets of binary and ternary mixture density and vi scosity data were measured at 20, 25, 30, 35-degrees-C and used then t o estimate the parameters of such equations and to check the precision of prediction. (The measurements were carried out in a vibrating-tube densimeter and in an Ubbelohde-type capillary viscometer.) Useful rel ations for the description of the concentration dependence of the prop erties under consideration with sufficient accuracy are found to be a density equation according to the cubic mixing rule and the viscosity equation published by Skubla (1981). In addition the method by Wei and Rowley (1985) was tested which predicts multicomponent liquid mixture viscosities from NRTL-model parameters for G(E) and H(E).