Elaboration of High Permeable Macrovoid Free Polysulfone Hollow Fiber Membranes for Air Separation

Abstract

In this work, polysulfone hollow fibers with oxygen permeance 70 L (STP)/(m2·h·bar) and selectivity α(O2/N2) = 6 were obtained. A decrease in the dope solution temperature allowed to diminish macrovoids due to the increase of the dope viscosity from 15.5 Pa·s at 62 °C to 35 Pa·s at 25 °C. To reduce the fiber diameter, thereby increasing the packing density, they were spun at high linear velocities. A hollow fiber membrane element was produced with effective membrane area 2.75 m2 and packing density 53%. Its air separation performance was evaluated to bridge laboratory studies and practical application.

Influence of Sodium Hypochlorite Treatment on Pore Size Distribution of Polysulfone/Polyvinylpyrrolidone Membranes

“…The dope solution was supplied to the spinneret using the gear pump. The schematic of the spinneret is presented in the work [ 7 ]. The ring duct diameter of the spinneret was 1.5 mm and the outer bore needle diameter was 1 mm.…”

“…Secondly, the dope solution should have a viscosity between 30 and 100 Pa•s at 25 • C. An insufficient value of viscosity may induce the formation of finger-like "macrovoids" which can lead to the appearance of defects in the fiber. On the other hand, when the viscosity value exceeds 100 Pa•s, the dope solution is hard to prepare, degas and spin into fiber [7]. Therefore, the resulting solution contained 57 wt.% of DMAc, 19 wt.% of PEG-400, 2 wt.% of PVP K-30 and 2 wt.% of PVP K-90.…”

“…Polysulfone (PSf) is a widely applied material to produce polymeric membranes for different applications [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 ]. In water treatment, these membranes are commonly modified by the addition of polyvinylpyrrolidone (PVP) to increase hydrophilicity and water permeance [ 9 , 19 , 20 , 21 , 22 , 23 ].…”

High-Selectivity Polysiloxane Membranes for Gases and Liquids Separation (A Review)

“…Membrane technologies are widely used in separation of gaseous and liquid media, in particular, in oil refining, gas processing, and petroleum chemistry [1][2][3][4]. The examples of such separations are nitrogen separation from air [5][6][7], helium separation from natural gas [8,9], hydrogen separation from process streams [10][11][12][13], trapping of highly volatile organic compounds from air media [1,14], etc.…”

“…suppliers of systems for membrane separation of organic vapor/air (gas) mixtures are MTR [100] and licensiates of the Helmholtz-Zentrum Geesthacht research center (HZG, former name GKSS): Borsig, SiHi, and Dalian Eurofilm [1]. The membrane separation systems supplied by these companies are mainly used in the production of polyolefins (separation of monomers), polyvinyl chloride (off-gas treatment), ethylene oxide, and vinyl acetate (ethylene separation); in storage terminals for crude oil and petroleum products (trapping of gasoline vapors from off-gases); at compressor stations for natural gas transportation (reduction of the concentration of С 3+ hydrocarbons) 4,5,6 ; and at small chemical and pharmaceutical enterprises [101]. The first installation for organic vapor recuperation based on membrane technologies was put into operation by GKSS GS-module in 1989 at the gasoline repository, and by 1995 already 20 membrane installations with the productive capacity of 100-2000 m 3 h -1 were supplied to enterprises for organic vapor recuperation [101].…”