Membrane gas absorption for CO2 capture from flue gas containing fine particles and gaseous contaminants

Membrane gas absorption contactor has been an effective alternative for CO2 capture, and usually installed at the outlet of wet flue gas desulfurization (WFGD) system. However, there are also residual SO2, fine particles and water vapor in desulfurized flue gas, which possibly has significant impact on the stable operation of CO2 absorption using membrane. In order to obtain a better understanding on the influence of these components, the capture process of CO2 using polypropylene (PP) hollow fiber membrane from flue gas containing fine particles and gaseous contaminants were investigated in this work. At first, simulated flue gas was used to study the effects of SO2, water vapor and fine particles on the CO2 capture respectively. Then the separation of CO2 using PP membrane was operated under the condition of actual coal-fired desulphurized flue gas. The results revealed that the absorption performance of membrane was slightly deteriorated at the individual presence of SO2 or water vapor while the effects fine particles was significant. Following the fine particles exposure, a bulk decrease of the CO2 removal efficiency was observed due to the deposition and adsorption of fine particles on the membrane surface and pores. In addition, water vapor could accelerate the deposition of fine particles.