Solubility of fatty acids in subcritical water

⿢We design an ultrasound-enhanced phase equilibrium apparatus to study the solubiity of fatty acids in subcritical water.⿢Both temperature and pressure had significant effect on solubility of fatty acids.⿢The maximum solubilities of stearic acid and palmitic acid were determined.⿢Ultrasonic field with a lower output frequency and a larger output power has a stronger acceleration effect on dissolution.

A phase equilibrium apparatus was designed to determine the solubilities of stearic acid and palmitic acid in subcritical water at different temperatures and pressures. The dissolution equilibrium time was measured. The effect of an ultrasonic field on dissolution equilibrium was also studied. The results showed that the maximum solubilities of stearic acid and palmitic acid were 0.136 g/100 g and 0.178 g/100 g in subcritical water at temperatures of 180 °C and 160 °C, respectively, and a pressure of 15 MPa for 30 min. An ultrasonic field also clearly promoted the dissolution of fatty acids in subcritical water. The dissolution equilibrium time was shortened to 20 min using ultrasonic oscillation (250 W, 20 kHz).

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