A comparative study of liquid-liquid extraction in different rotating bed contactors

• Published in: Chemical engineering and processing Vol. 132; pp. 187 - 193
• Main Authors: Karmakar, Sudhanya, Bhowal, Avijit, Das, Papita
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.10.2018
• Subjects: Co-current; Hexavalent chromium; Liquid-liquid extraction; Mass transfer; Rotating bed contactors; Liquid-liquid extraction; Hexavalent chromium; Rotating bed contactors; Co-current; Mass transfer
• ISSN: 0255-2701; 1873-3204
• DOI: 10.1016/j.cep.2018.09.009

[Display omitted] •Cr (VI) removal by liquid-liquid extraction studied in rotating bed contactors.•Comparative study between rotating bed contactors not reported earlier.•Volumetric mass transfer coefficient highest in rotating spiral bed contactor.•Volume of traditional extractors can be reduced ∼25 times using rotating contactors. This study examines the influence of the internal structure of the rotor of rotating bed contactors on mass transfer characteristics in liquid-liquid extraction. Experiments were carried out in rotating spiral bed, rotating zigzag bed, and rotating packed bed. The system studied was removal of hexavalent chromium from an aqueous solution using Aliquat336 (dissolved in kerosene) as the extractant. The stage efficiency in all the rotating contactors increased with rotational speed and flow rates but decreased with feed concentration. The rotating spiral bed extractor (RSB) provides significant improvement over other rotating packed bed (RPB). The stage efficiency attained in RSB was ∼99% within a bed of radial depth ∼0.06 m at aqueous and organic flow rates of 13.34 × 10−6 m3s−1and 3.34 × 10−6 m3s-1respectively. The overall volumetric mass transfer coefficient is over twenty five times higher than that in conventional extractors like mixer settler and fixed bed.