Comparison of hydrodynamic and mass transfer performance of SMR, Raschig ring and pulsed perforated plate column

Cyanex 923 has been proposed as an extractant for the removal of sulphuric acid from copper tank house bleed streams. This process requires many stage s and so is ideal for column operation. This paper presents a comparison be tween three types of column for this service. The new SMR packing marketed by Glitsch is the first packing developed specifically for liquid-liquid ex traction service and is compared with a column packed with Raschig rings an d a pulsed perforated plate column. Both the hydrodynamic and mass transfer behavior of these columns are prese nted for the 50% Cyanex 923 in kerosene/H2SO4/water system. The results ind icated that this system is unusual in that the HTU values obtained were hig h and so the efficiency is low. This is ascribed to a slow heterogeneous re action at the interface, and/or to very slow diffusion in the highly viscou s dispersed phase droplets that were observed. The SMR packing was found to give H-ox values about 47% below those for Raschig rings.