Two- and three-liquid phase equilibria in the system water+2-heptanone+caprolactam+ammonium sulfate: experiments and modeling

Selection and evaluation of alternative solvents for caprolactam extraction

“…3, it could be concluded that several solvents or solvent mixtures showed an acceptable to favourable distribution ratio relative to toluene. These solvents were heptanone, which was already known to possess a too high mutual solvent solubility [8], propyl-butyrate, octanone and the solvent mixtures with methylcyclohexanol and heptanol as polar components. Therefore, the latter three solvents were further investigated.…”

“…For a possible alternative solvent the system water + caprolactam + replacement solvent should show a capacity and a mutual solvent solubility comparable to those of the currently applied solvents or better [2]. Research on alternative solvents in literature is limited to 1-heptanol and 2-heptanone, where the influence of caprolactam and ammonium sulfate concentrations and temperature on the phase compositions is described [7,8]. For cyclohexanol, the binodal is determined at 293 K [9].…”

“…From this figure, it can be concluded that no pure solvent is present with a polarity comparable to benzene or toluene. From literature, it is known that the more polar compounds show a larger capac- ity towards caprolactam and a higher mutual solubility [7][8][9][10], which is shown in Fig. 2.…”

Liquid–liquid and liquid–liquid equilibrium for ternary system water–acetonitrile–cyclohexene at 298.15 K

“…An analysis of the literature revealed approximately 60 experimentally-studied ternary systems. Currently, the systems most investigated are those containing water [4][5][6][7][8][9][10][11][12].…”

Liquid+liquid equilibria for the quaternary systems of (water+acetic acid+mixed solvent) at 298.2K and atmospheric pressure

“…Because of this the separation of acetic acid from aqueous solutions is industrially important. For this purpose various solvents has been used by several researchers and reported in literature [2][3][4][5][6][7][8][9][10]. Solvents for extraction should have high selectivity for one of the components, high capacity, capability to form two phases at reasonable temperatures, a minimal solubility in the carrier, capability of rapid phase separation should be noncorrosive and nonreactive, and have good thermal stability.…”