Li, Wei; Bai, Bingyang; He, Rongrong; Song, Jianfeng; He, Tao

SEPARATION AND PURIFICATION TECHNOLOGY

2024, 328, 1873-3794

Li, Wei; Bai, Bingyang; He, Rongrong; Song, Jianfeng; He, Tao

Comparing to conventional liquid-liquid extraction, membrane extraction is an efficient and environmentally friendly separation technique to recover lithium from the salt-lake brine. Development of suitable hydrophilic solvent resistant nanoporous membranes for membrane extraction has been based on bench-scale small module. Because module design has significant impact on the performance, this work reported a novel multiframe flat membrane contactor module (MFMC) for lithium extraction from synthetic brine. The hydrophilic poly (ethylene-co-vinyl alcohol)/sulfonated poly(ether ether ketone) membrane supported with polypropylene nonwoven (EVAL/SPEEK-NW) was prepared for module evaluation. The membrane mass transfer coefficients km of 1.1 x 10-6 m/s was obtained by Wilson plot. The global mass transfer coefficient Ke increased from 4.5 x 10-7 m/s to 9.9 x 10-7 m/s following the flow velocity from 0.4 to 1.8 cm/s in membrane extraction. We further evaluated the characteristics of MFMC via height of transfer units (HTU) and module efficiency (ME). High module efficiency of 90% was obtained, demonstrating MFMC's efficient flow distribution. HTU of 28 m was estimated and was expected to decrease to 3 m by optimizing thickness of gasket and spacer as well as membrane performance. The MFMC module effectively reduced the loss of tributyl phosphate (TBP) by 91% comparing to liquid-liquid extraction. The research presented herein provides a flat membrane module design for potential future application of membrane extraction in wide applications.