Separation of phenantrene from anthracene oil using supercritical carbon dioxide

Supercritical fluid extraction (SFE) is a relatively new separation technique that has received much attention in recent years. This process is an alternative to distillation or liquid extraction. Its main advantage over the conventional ones is that the dissolved extract may be completely separated from the supercritical fluid simply by decreasing the pressure. In recent years considerable effort has been devoted to the measurement of equilibrium solubility data for solids in supercritical fluids. A coal tar distillate, anthracene oil, which contains 34.46 mass-% phenanthrene, 33.8 mass-% anthracene, 13.89 mass-% carbazole and other impurities, was used as the model mixture. In this study, an experimental flow-type apparatus has been designed to determine solubility data for the main components of anthracene oil (phenanthrene, anthracene, and carbazole) as a binary, quaternary, and multi component mixture in supercritical carbon dioxide. The equilibrium solubilities were measured at 45degreesC isotherm, over a pressure range of 98-200 bar. The separation of phenanthrene from anthracene oil has been also studied by supercritical carbon dioxide at different temperatures and pressure in an extracting vessel containing 27 sieve trays.