Recycling of CO2 on a Supercritical Fluid Chromatography (SFC) Pilot Unit

Except for analytical and semiprep instruments, eluent recycling after solute separation should be an ordinary feature of any supercritical fluid extraction and chromatographic equipment. But it should be stressed, that gaseous eluent from separators always contains some traces of solute and co-solvent, entrained as particles or vapor. Hence, in order to recycle the CO2 and reuse it, the gas leaving the separators must be further purified. This purification step must provide clean CO2 at the same pressure as a fresh fluid delivered from the supply unit (40 to 50 bar).