Refining the scale-up of chromatographic separations

The use of heavily loaded columns and complex processing conditions makes scale-up of chromatographic separations a non-trivial process. The wide ranges of process conditions that must be investigated demands that a large number of preliminary experiments must usually be made in small columns and laboratory-scale work stations, These preliminary data can be biased by improper column packing, poor distributors and dispersion in auxiliary apparatus, and it is important to understand these disturbing factors in detail. Moreover, it is precisely at this macroscopic level that our understanding of the chromatographic process is weakest, for large columns as well as small. This paper addresses three of these factors: Efficient elimination of peripheral effects and characterization of both header flow distribution and packing non-uniformity. This will be done using a variety of experimental and analytical approaches including nuclear magnetic resonance imaging, computational fluid dynamics and mass transfer, and careful experimentation. (C) 1998 Elsevier Science B.V.