Physicochemical Characteristics of Hollow Fiber Structured Packings in Isopropanol/Water Distillation

Three kinds of hollow fiber membrane contactors, polyether sulfone (PES), polysulfone (PS), and polypropylene (PP), were applied in IPA/water distillation to check how the material and structure of membranes would affect the performance. The Hansen solubility parameter (HSP) was calculated to analyze the compatibility between polymers and IPA in operation. It was found that a hydrophobic asymmetric microporous membrane coating thin dense layer on the liquid side with good compatibility worked better in the process, while the membrane with interconnected porous morphology was more favorable for decreasing Rm and more sensitive to vapor load, which might worsen operation stability. Even a slight wetting (<20%) of membrane could result in a sharp decrease as high as 70% of the mass transfer across membrane. As before, all self-made modules in distillation could easily operate at a vapor velocity 5−6 times higher than the flooding limits for conventional packings and achieved an attractive low value of the height of transfer umit (HTU) less than 0.1 m, in which PES hollow fibers performed with excellent stability and gained the highest mass transfer coefficient KL in the experiment.