Separation performance of PEBAX/PEI hollow fiber composite membrane for SO₂/CO₂/N₂ mixed gas

In this study, a poly(ether-b-amide) (PEBAX)/polyetherimide (PEI) composite hollow fiber membrane was prepared by a continuous coating process to remove SO₂ from mixed gases. The SO₂ in the emission gas affected the sorbents in the CO₂ capture and separation (CCS) process. The composite membrane used in the present study was characterized by Fourier transform infrared spectroscopy (FT-IR), and the morphology was examined by scanning electron microscopy (SEM) to understand and correlate the morphology with the performance of membrane. The effects of the parameters involved in the spinning of PEI hollow fiber and PEBAX layer deposition on the permeation of the resulting composite membranes were also investigated. The PEBAX/PEI composite hollow fiber membranes showed an increase in the operating pressure; the permeance of SO₂ and CO₂ increased, but the permeance of N₂ was negligibly changed. The permeance of SO₂ sharply decreased and the selectivity of SO₂/CO₂ decreased as the temperature difference increased. In addition, hollow fiber membrane processes were designed using a simulation program to estimate the membrane area as a function of the operating conditions (pressure, temperature, stage cut) with the intent to maximize the SO₂ removal efficiency. The resultant optimization decreased 50-60% of the membrane area by increasing the operating pressure and temperature.