| Aiming to provide reference for the supercritical CO2 purification process in the post-treatment stage of biodiesel production, oleic acid, anhydrous ethanol, and glycerol contained in the system in the post-treatment stage of biodiesel production were used as raw materials, and the process of oleic acid-glycerol-anhydrous ethanol co-blended system reaching phase equilibrium in CO2 at a temperature of 308 K was observed in the SYLG-01 supercritical fluid phase equilibrium experimental device.The results showed that the oleic acid-glycerol-anhydrous ethanol co-blended system was a liquid-liquid phase, and it was gas-liquid-liquid state at the beginning with CO2 in the phase equilibrium experimental device,and as the pressure increasing, when CO2 reached the supercritical state, the mobility and transferability between different phases were enhanced and the co-blended system became homogeneous. Therefore, changing the pressure of supercritical CO2 could extract and separate the free fatty acids and by-products glycerol in the system at the same time. |
