Adsorptive separations using supercritical frontal analysis chromatography

Many food products and pharmaceuticals industries are looking to integrating supercritical extraction and separations processes to fulfill processing needs due to limitations and regulations concerning the use of organic solvents. One such technology, which may affect these industries, is continuous supercritical adsorptive separation a processing technology similar to the separation process of xylenes developed at UOP. Many products like pharmaceuticals and other human consumables could be processed more economically and with higher purity by supercritical fluid adsorption/desorption processes. Past studies, however, have.focused on single-component adsorption/desorption involving a supercritical mobile phase, whereas adsorptive separations involving supercritical fluids are multicomponent systems. Accurate experimental techniques which can determine both multicomponent solubilities in supercritical fluids and multicomponent adsorption isotherms in the presence of supercritical fluids, were developed to investigate the multicomponent supercritical adsorption phenomenon. A dynamic column model developed takes into account column dispersion as well as mass transfer and diffusive resistances. Experimental isotherm data incorporated into the model can predict the breakthrough profiles. An extension of pulse chromatography was used to identify the important hydrodynamic and transport parameters, and operating conditions are identified for optimal separations.