Separation of Carboxylic Acids from Aqueous Solutions using Hollow Fiber Membrane Contactors

Abstract

Separation of formic, acetic, and propionic acids from the aqueous stream using membrane solvent extraction has been studied using three different membrane contactors made of polysulfone (PS), polyethersulfone (PES), and polyvinylidene fluoride (PVDF) using two different solvents; including ethyl acetate (EA) and diisopropyl ether (DIPE). The efciency of the membrane and extractants were obtained by partitioning coefcient comparison. The overall mass transfer coefcient was determined by resistance in series model. The results indicated signifcant difference amongst the performance of the membranes for the same system, even though one usually would expect the membrane only to play a role in facilitating high interfacial mass transfer contact area. The observable results of high distribution coefcient were obtained for the propionic acid with the PVDF membrane and EA as an extractant, on the other hand, the formic acid with PVDF and EA as extractants obtained a better mass transfer coefcient of 9×10-6 m/s.