PURIFICATION OF POLYCYCLIC AROMATIC-COMPOUNDS USING SALTING-OUT SEPARATION IN HIGH-PRESSURE CO2

Gas antisolvent crystallization has the potential for application in the recovery of valuable compounds from liquid solution, and in the separation of solid-solid mixtures. Experimental data are presented for a mixture of anthracene and anthraquinone dissolved in cyclohexanone which was expanded by a gaseous anti solvent, CO2. The pressure range is 0.1 to 12 MPa, and the temperature is 291 to 313 K. The relation of salted-out yield and normalized feed concentration gives an important parameter, the so-called minimum solubility, from which supersaturation can be defined for gas antisolvent crystallization. Effects of initial feed concentrations of solid solutes, temperature, and pressure on the separation of anthracene and anthraquinone have also been studied.