Foaming Effect on Random Packing Performance

The effect of foaming on the performance of 16 mm Pall rings was determined in a 0.15 m distillation column with a bed depth of 1.23 m. The tests were conducted with the methanol/water system at 1.0 bar pressure. A controllable foaming inside the packed bed was generated successfully with the addition of the surfactant, Triton X-100, to the reflux stream. The performance of the packing with and without foaming was determined and compared. It was found that foaming reduces the mass transfer efficiency, and lowers the capacity of the random packing tested. The results also show significant increase of the bed pressure drop caused by foaming. In addition to the distillation tests, the foaming tendency and surface tension were measured for the methanol/water system at different methanol concentrations. Foaming tendency was measured using ASTM methods. The measurements revealed direct correlations between foaming tendency of the mixtures and the corresponding changes in surface tension.