Measurements of liquid–liquid equilibria of water+ε-caprolactam+electrolyte+organic solvent systems

In this study experimental liquid–liquid equilibrium data are reported for the systems water+ε-caprolactam+1-heptanol, and water+ε-caprolactam+1-heptanol+ammonium sulfate at 20°C, 40°C, and 60°C. It is shown that with increasing temperature, the solubility of ε-caprolactam in the organic phase increases to a greater extent than the solubility of ε-caprolactam in the aqueous phase. An increasing salt concentration in the aqueous phase results in a salting out of ε-caprolactam into the organic phase.