Process Intensification of Liquid-Liquid Extraction in Rotating Packed Bed

摘要

The object of this study is to intensify the liquid-liquid extraction. Experiments were carried out inside a Rotating Packed Bed (RPB) operating at centrifugal force varying between lOOg and 1000g. The system chosen for experimentation was removal of hexavalent chromium from aqueous solution using aliquat-336 as an extractant. The effect of centrifugal force on overall volumetric mass transfer coefficient (K_La) was investigated. Mass transfer characteristics of RPB were observed with the variation in rotational speed (300-1100rpm), aqueous phase (0.4-1.2 L/min) and organic phase (0.05-0.15 L/min) flow rate, feed (25-200 mg/L) and extractant (0.5-1.25 vol%) concentration. Significantly higher value of K_La (~20-25 times) was achieved in RPB than that achieved in comparison with conventional packed bed extractor wherein flow is dictated by terrestrial gravity. In other words, same separation efficiency can be obtained within a much smaller rotating extractor.