ABSTRACT
Isolation of value-added organic compounds using membrane separation processes has gained huge importance in chemical, pharmaceutical and food industries. The present work focuses on application of liquid-liquid membrane contactors and membrane distillation (MD) processes for recovery of organic acids from aqueous streams and volatile hexane solvent from oil miscella, respectively. Recovery of levulinic acid from an industrial effluent and acrylic acid from synthetic solution was carried out by reactive extraction through liquid-liquid membrane contactors using tri-n-octylamine (TOA) as an extracting agent. The performance of indigenously synthesized microporous hydrophobic polyvinyl chloride (PVC) and ultraporous polyvinylidene fluoride (PVDF)/polyvinylpyrrolidone (PVP) blend membranes was investigated. Glycerol additive in PVC dope facilitated maximum levulinic acid extraction efficiency due to a larger pore size created by its dissolution in the water during the membrane preparation by a phase inversion technique. On the other hand, the PVDF/PVP membrane exhibited nearly 30% acrylic acid extraction. Recovery of hexane solvent from sunflower oil miscella was performed using indigenous ultraporous PVC membrane and a commercial tubular ceramic membrane module. The study showed that both PVC and ceramic membranes exhibited hexane purity of > 95% in permeate. The proposed research study infers that the membrane processes employed proved their potential for recovery and recycle of valuable chemical entities by offering safer, eco-friendly and economical routes, as against conventional processes.
