What are the key considerations when scaling up a liquid-liquid extraction column?

Scale-up challenges include: maintaining drop size distribution (affects interfacial area and mass transfer), avoiding backmixing (increases with diameter), ensuring proper phase distribution, and matching residence time. Key parameters: maintain similar dispersed phase holdup, specific power input for agitated columns, and superficial velocity ratios. Pilot data correlation methods include using HTU correlations with diameter correction factors. Often 20-30% efficiency derating is applied when scaling from lab/pilot to commercial scale.