Fouling of Impurities in Desulfurized Flue Gas on Hollow Fiber Membrane Absorption for CO2 Capture
详细信息 查看全文
文摘
Membrane-based absorption shows numerous potential applications for CO2 capture from flue gas. However, during the process, membrane fouling is not only caused by the wetting but also induced by gaseous components (SOx, NOx, and water vapor) and fine particles in the flue gas. In this work, the synergetic effects of water vapor coupling with SOx and NOx as well as the fine particles were investigated to better understand the membrane fouling and the performance of polypropylene hollow fiber membrane modules for CO2 capture in actual industrial conditions. The CO2 removal efficiency and the mass-transfer rate over time were studied under different feed gas flows of various gaseous composition schemes. The membrane performance suffered from a notable decrease after exposure to SO3 and particles, and in a wet gas stream, the effects of SO3 and particles were irreversible, whereas the influence of SO2 and NO2 can be recovered by N2 sweeping. The characterization results of membrane modules confirm that the membranes are polluted by gaseous and particle impurities to different extents, and after long-term operation in flue gas containing impurities, the morphology of materials changed substantially. The reduction of contact angles illustrated that the hydrophobic property decreases obviously after exposure to SOx. Moreover, the results of Energy dispersive spectrometry and Fourier transform infrared spectroscopy indicated that the interaction of stranded SO3 and the membrane formed a new group. During the process of membrane CO2 adsorption from flue gas containing fine particles, the pores of the membrane were blocked by fine particles and the surfaces were covered by a particle layer, which occupies the efficient contact area and leads to an increase of mass-transfer resistance and reduced membrane performance.