Power-efficient mass transfer of a novel pulsating multi-packed bed liquid - liquid extractor

This paper presents the development and performance evaluation of a new pulsating packed bed contactor designed for optimized diffusion-controlled liquid-liquid operations. Targeting applications like aromatics separation in petroleum, phenol removal from wastewater, and heat-sensitive material extraction (e.g., antibiotics), the contactor offers substantial advantages over traditional mechanical systems – notably, lower power consumption for equivalent production rates. Using the widely studied extraction of acetic acid from toluene-acetic acid by water as a model system, this work comprehensively investigates the factors impacting mass transfer within the pulsating contactor. Key variables explored include physical properties of the feed solution, oscillation frequency and amplitude, initial concentration of solute, flow rates, bed height, packing diameter, and bed spacing. Results reveal a significant enhancement in mass transfer with increasing frequency, amplitude, initial concentration, continuous phase flow rate, and dispersed phase flow rate. Interestingly, while increasing bed height initially improves mass transfer up to a specific point, further height increase exhibits a diminishing return. Packing sphere diameter shows minimal impact, while bed spacing has a negligible effect. A novel dimensionless equation effectively correlates the pulsating multi-packed bed data for broader applicability. To assess economic viability, the study also measures the mechanical power consumption under various operating conditions. Finally, diverse potential applications across pharmaceuticals, chemicals, biochemicals, petroleum, and nuclear fuel reprocessing are highlighted, showcasing the broad utility of this innovative mass transfer technology.