Hydraulic and mass-transfer characteristics of Raschig Super-Pak 250Y

•Hydraulic, hydrodynamic and mass-transfer characteristics of Raschig Super-Pak 250Y.•Excellent gas mass-transfer performance and improved hydraulic behavior of packing.•Evaluation of all six packing constants of Billet and Schultes model.•HETP values for distillation of C6/C7 and methanol/n-propanol mixtures.•Axial mixing effect on data transfer from absorption to distillation.

Our paper presents hydraulic, hydrodynamic and mass-transfer characteristics of the Raschig Super-Pak 250Y high-capacity structured packing measured under absorption conditions. The measurements were performed in the absorption column of inner diameter of 0.29 m using proven aqueous test systems. Measured data reveal excellent gas-phase mass-transfer performance and improved hydraulic behavior which is in agreement with the data provided by the vendor. There was found significant degree of the liquid-phase axial mixing on the packing. All six packing constants of the model proposed by Billet and Schultes (1999) were evaluated. The HETP values for distillation of C6/C7 and methanol/n-propanol mixtures were predicted using the BS-model with the evaluated constants and plug flow assumption. Predicted HETPs were found to be in a poor agreement with those measured under distillation conditions. However, we do not address this disagreement to fundamental impropriety of the test systems or the inability of the BS model to transfer the data from absorption conditions to distillation ones. We demonstrate that rather accurate values of HETP can be obtained when the influence of the liquid phase axial mixing is involved into the HETP prediction. The need for incorporation of the more sophisticated hydrodynamic models into simulation software becomes evident.

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