Emission of sulfur dioxide (SO2) from coal power plants has to be controlled and minimized to reduce environmental risk. This study aimed to investigate the hollow fiber composite membrane was used for the removal of SO2 from a SO2/CO2/N2 mixed gas. Moreover, for the improvement of SO2 removal efficiency, the polyetherimide (PEI) membrane was coated with poly(vinyl chloride)‐graft‐poly(oxyethylene methacrylate) (PVC‐g‐POEM). The PVC‐g‐POEM/PEI composite hollow fiber membrane was extensively characterized by various techniques including scanning electron microscopy, Fourier transform infrared spectroscopy, and atomic force microscopy. Experiments with permeation of SO2, CO2, N2, and a ternary gas mixture were carried out to observe membrane behavior in response to different operating conditions. As a result, permeance of SO2 was 105–2705 GPU and selectivity of SO2/CO2 was 3.9–175.6. From the mixed gas separation experiment, the maximum SO2 removal efficiency reached up to 84.5%. © 2014 American Institute of Chemical Engineers AIChE J, 60: 2298–2306, 2014

BACKGROUND: In this study, a polyethersulfone composite hollow fiber membrane was used for the separation of water vapor from mixed gas. For improvement of the separation properties, the fabricated membrane was coated with cellulose acetate (CA) and polyethylene glycol (PEG). RESULTS: Experiments on the permeation of water vapor and N2 gas mixture were performed to observe membrane behavior as a function of the coating conditions, such as the composition and molecular weight of PEG. The water vapor permeance and selectivity of water vapor/N 2 improved from 68.5 GPU to 444.1 GPU and from 76.1 to 175.5, respectively, using 5 wt% PEG 2000 blended coating solution. CONCLUSION: An increase in the PEG content and molecular weight of the coating solution affected the permeance and selectivity due to the hydrophilicity of PEG and the structural changes of the coating layer.

Sulfur dioxide (SO 2 ) is the major air pollutant which is emitted from the power plant. In this study, hollow fiber membrane (HFM) separation process is applied for the improvement of SO 2 removal efficiency in the post-combustion gas. HFM was produced by dry/wet phase inversion method and then coated with Polydimethylsiloxane (PDMS). The membrane morphology and characterization were examined with help of scanning electron microscope (SEM), energy dispersion of X-ray spectroscopy (EDX), Fourier transform infrared (FT-IR) and atomic force microscopy (AFM). Polyethersulfone (PES) hollow fiber membranes were tested for the SO 2 /N 2 binary mixed gas separation. Single gas permeance of SO 2 , N 2 , and binary mixture gas (200 ppm of SO 2 ) separation experiment was initiated to observe membrane behavior according to temperature and pressure difference and retentate flow rate. As a result, permeance of SO 2 was 24.9-47.4 GPU and selectivity of SO 2 /N 2 was 1.6-4.2. From the mixture gas separation experiment, SO 2 removal efficiency increased according to stage cut and operating pressure.

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BACKGROUND In this study, a polymeric membrane process was investigated to avoid the poisoning of CO2 sorbents with SO2 during the carbon capture and separation (CCS) process. Two types of hollow fiber composite membranes were prepared using poly(ether‐b‐amide) (PEBAX) and cellulose acetate (CA) as composite materials. RESULTS Both of the composite membranes exhibit a trade‐off between the pure gas permeance and the ideal selectivity. The PEBAX1657/PEI exhibited higher permeance than CA/PES due to the morphology of the substrate and the effects of the coating material. A mixed‐gas separation experiment investigated the SO2 removal efficiency and the CO2 loss ratio. The SO2 removal efficiency and CO2 loss ratio were found to be positively correlated with the permeance of the gas components. A multi‐stage membrane process was designed to reduce the CO2 loss ratio with a 90% removal efficiency of SO2. Compared with a single‐stage process, the CO2 loss ratio was decreased by up to 16.1%, and the membrane area was estimated at 18.1 m2 for the multi‐stage process. CONCLUSION A multi‐stage membrane process was designed using different types of membrane modules to decrease CO2 loss ratio without sacrificing SO2 removal efficiency. © 2014 Society of Chemical Industry