Chromatographic processes using supercritical eluents

Study of preparative chromatographic systems in particular, Simulated Moving Bed (SMB) processes using supercritical fluids as eluents

The use of supercritical fluids, especially CO₂, as solvents in simulated moving bed process has a two fold advantage.
1. CO₂ is an environmentally benign substance which is suited for use in food and pharmaceutical applications.
2. The dependence of the henry’s constant of the solutes to be separated on the fluid phase density makes it convenient to perform gradient operations which improve the productivity and lower the solvent consumption.
It has been shown both experimentally and theoretically that running the SF-SMB under pressure gradient mode (where the pressure in the system decreases from Section 1 to Section 4) offers productivity improvement over the isocratic mode of operation (where all sections are operated at the same pressure [1,2,3].

However, to optimize the system performance, it is important to perform detailed simulations of the process. This involves the study of the behaviour of chromatographic columns operated under high flow rates and under overloaded conditions. These studies are being carried out on a lab scale Supercritical Fluid Chromatography (SFC) unit where the effect of various operating parameters, like pressure, temperature and modifier concentrations are studied. The knowledge obtained from these studies will be used for modelling and optimization of the SF-SMB process.

 

Publications

[1] Mazzotti M., G. Storti, M. Morbidelli, Supercritical fluid simulated moving bed chromatography, Journal of Chromatography A 786 (1997) 309-320.

[2] Denet F., W. Hauck, R. M. Nicoud, O. Di Giovanni, M. Mazzotti, J. N. Jaubert, M. Morbidelli, Enantioseparation through supercritical fluid simulated moving bed (SF-SMB) chromatography, Industrial & Engineering Chemistry Research 40 (2001) 4603-4609.

[3] Di Giovanni O., M. Mazzotti, M. Morbidelli, F. Denet, W. Hauck, R. M. Nicoud, Supercritical fluid simulated moving bed chromatography II. Langmuir isotherm, Journal of Chromatography A 919 (2001) 1-12.