REFINING THE SCALE-UP OF CHROMATOGRAPHIC SEPARATIONS

The use of heavily loaded columns and complex processing conditions ma kes scale-up of chromatographic separations a non-trivial process. The wide ranges of process conditions that must be investigated demands t hat a large number of preliminary experiments must usually be made in small columns and laboratory-scale work stations, These preliminary da ta can be biased by improper column packing, poor distributors and dis persion in auxiliary apparatus, and it is important to understand thes e disturbing factors in detail. Moreover, it is precisely at this macr oscopic level that our understanding of the chromatographic process is weakest, for large columns as well as small. This paper addresses thr ee of these factors: Efficient elimination of peripheral effects and c haracterization of both header flow distribution and packing non-unifo rmity. This will be done using a variety of experimental and analytica l approaches including nuclear magnetic resonance imaging, computation al fluid dynamics and mass transfer, and careful experimentation. (C) 1998 Elsevier Science B.V.