Performance Comparison of HETP Correlations for High-Capacity Structured Packings

The prediction of HETP by mass transfer correlations is important to the successful design of packed distillation columns. A HETP performance comparison of five structured packing correlations in the literature was carried out. The correlations evaluated were Gualito, Billet and Schultes, Delft, Aspen, and Song. Experimental HETP data consisted of total reflux data from Fractionation Research Inc., with cyclohexane/n-heptane and o/p-xylene as the test systems of interest. The data was collected over a range of high-capacity structured packings, including MellapakPlus 252.Y, 452.Y, and 752.Y. This paper presents the performance of the studied correlations, as well as discusses major differences in behavior between the models. In addition to HETP performance, effective area predictions by all models are presented and analyzed. Overall, the Billet and Schultes and Song correlations provided the lowest error in HETP predictions across all packings, but the other models displayed strength in specific packings or systems.