RELATIVE SUPERSATURATION RATIO AND SEPARATION FACTOR IN CRYSTALLIZATION WITH HIGH-PRESSURE CO2

Crystallization in the presence of high pressure gas as antisolvent co uld be applied for the recovery of valuable compounds from liquid solu tion. A study of separation behavior is presented here for a mixture o f anthracene (AN) and anthraquinone (AQ) in cyclohexanone (CX) expande d with a gaseous antisolvent, CO2. The pressure range was 0.1 to 12 MP a; the temperature was either 292 or 313K. Separation factors were obt ained from the measured salted-out yields and the supersaturation of e ach solute could be also obtained for this pressure-tuning crystalliza tion. The separation factor varies almost linearly with relative super saturation ratio in the crystallization of anthracene-anthraquinone fr om cyclohexanone and CO2.