Hydraulic and Mass Transfer Performances of a Commercial Hybrid Packing: The RSP200X - Key Modelling Parameters for Gas Treatment Applications

Abstract

The use of the last generation of Raschig’s structured packings, Raschig SuperPack (RSP) has been investigated for scrubbing columns operating at high liquid loads, for their potential to increase capacity while maintaining mass transfer efficiencies at high levels. IFPEN has measured pressure drops, flooding limits, liquid and gas side mass transfer coefficients and interfacial areas for the RSP 200X. Flooding limits were in agreement with literature, however at high liquid loads and for tested X-Style RSP they were 30-40% lower than those calculated with the Winsorp Software. This indicates that extrapolation of flooding models should be used with caution to size column diameters for fluid systems and liquid loads that differ from those from which these models were derived. With the support of the present results a modified version of Winsorp has been elaborated for high liquid loads and X-Style RSP. RSP 200X develops a high interfacial area, close to the one of a standard 250 m²/m³ structured packing. One important difference however has been noted about the impact of the gas flowrate on the interfacial area. While for standard packings the gas flow rate is often considered to have only a small effect on area when operating below the loading point, the effect measured on RSP200X is significant and of the same order as for liquid load. Measurements of k_La_e further confirm that these latest generations of packings show different trends when compared to standard structured packings. Detailed characterization tests are therefore highly recommended to estimate the performances of these packings in terms of hydraulics and mass transfer properties. In some distant future, it is believed that CFD calculations (gas and gas/liquid) will help to better understand and model such phenomena.