Influence of temperature on the liquid-liquid equilibria containing two pairs of partially miscible liquids. Water + nitromethane + 1-butanol ternary system.

GÓMEZ MARIGLIANO, ANA CLELIA; MÓNICA GRAMAJO; SÓLIMO, HORACIO

FLUID PHASE EQUILIBRIA

ELSEVIER SCIENCE BV

Año: 1998 vol. 149 p. 309 - 322

0378-3812

In order to show the influence of the temperature on the liquid?liquid equilibria and obtain an equilateral triangular prism with temperature as the vertical dimension for waterqnitromethaneq1-butanol ternary system, its solubilities and equilibrium data starting at 303.15 K are reported. One region of immiscibility band type curve. is shown between 303.15 K and 340.5"0.5 K, but when the temperature increases beyond this value 2 separate binodal curves appear. Solubility data of the 2 partially miscible binary systems: waterq nitromethane and waterq1-butanol were also obtained. From these experimental results, both binary upper critical solution temperatures UCST. were reported. When the temperature is decreased below the lower CST, the ternary system presents 2 binodal curves expanding toward each other until they meet with a common plait point at the lowest point on the ridge. This point ?col? or saddle point. is situated at 340.5 K"0.5 K with a ternary composition: w s0.61; w s0.22 and w s0.17. Tie line data were satisfactorily correlated by the 1 2 3 method of Othmer and Tobias wD.F. Othmer, P.E. Tobias, Ind. Eng. Chem., 34 1942. 693?696x on a mass-fraction basis, and their plait point coordinates estimated when 2 separate binodal curves were present. From experimental distribution coefficients and selectivities 1-butanol appears to be a good solvent for extraction purposes particularly when the process is carried out at room temperature.