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

Gas antisolvent crystallization has the potential for application in t he recovery of valuable compounds from liquid solution, and in the sep aration of solid-solid mixtures. Experimental data are presented for a mixture of anthracene and anthraquinone dissolved in cyclohexanone wh ich 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 s alted-out yield and normalized feed concentration gives an important p arameter, the so-called minimum solubility, from which supersaturation can be defined for gas antisolvent crystallization. Effects of initia l feed concentrations of solid solutes, temperature, and pressure on t he separation of anthracene and anthraquinone have also been studied.