A strategy for tailored design of efficient and low‐pressure drop packed column chromatography

Packed chromatographic column, with higher efficiency and lower pressure drop is designed by using inert core adsorbents as stationary phase. The analytical solutions for moments and height equivalent to a theoretical plate (HETP) are given under the conditions of linear adsorption kinetics by taking into account of the axial dispersion, film mass‐transfer resistance, intraparticle diffusion resistance, and the sorption rate for chromatographic column packed with inert core adsorbents. By minimizing HETP, a nonlinear algebraic equation was derived to predict the optimized value of the inert core radius. For a given adsorbent with the optimized inert core radius, a strategy was presented to tailor the design of new packed chromatographic column with higher efficiency and lower pressure drop. As an example for supercritical carbon dioxide chromatography, reduced equations in terms of dimensionless inert core radius were derived by “order of magnitude” analysis. The quantitative analysis shows that the major benefit of the inert core adsorbent is a shorter diffusion path compared to conventional fully porous particles. The shorter diffusion path reduces dispersion of solutes and minimizes peak broadening leading to lower pressure drop while maintaining high‐separation efficiency. © 2010 American Institute of Chemical Engineers AIChE J, 2010