| The power plants of our country rely mainly on coal-burning, which releases SO2 and NOX to the atmosphere. This two kinds of gas form acid rain in the atmosphere and the environment will be severely polluted. Therefore, controlling the discharge amount of SO2 and NOx in the flue gas becomes an urgent request.The subject investigated in this paper was the removal of SO2 and NO in the flue gas on PAN-ACF (Polyacrylonitrile-based Activated Carbon Fiber). In this paper, the physical and chemical properties of PAN-ACF and the exterior factors such as the concentration of SO2 and NO, W/Q ratio, temperature, O2 and H2O affected to the removal of SO2 and NO was systematically studied. In addition, the removal effect of SO2 and NO on PAN-ACF treated by different catalysis methods was put to test and the interaction of SO2 and NO existed in the flue gas at the mean time was studied. Finally the oxidizing reaction mechanism of SO2 and NO on the ACF was analyzed and SO2 reaction model and equilibrium reaction rate equation were established respectively.PAN-ACF was treated by two of different catalysis methods and then analyzed by specific surface texture analyzer and x-ray photoelectron spectroscopy (XPS). Analysis showed that the specific surface texture and the amount of functional group of the catalyzed sample had changed. The sample, soaked by sulfuric acid and liquid ammonia, was introduced lots of oxygen-containing and nitrogen-containing functional groups and the specific surface area was decreased and the pore size was enlarged. Experiments proved that the nitrogen-containing functional groups enhanced the adsorption activity for SO2 and NO.Experiments found that the larger the W/Q ratio is, the shorter the breakthrough time is, the higher the removal efficiency is. It is unfavorable for PAN-ACF's removal effect of SO2 and NO as the temperature rises. As the percentage of volume concentration of O2 increases, the adsorption and oxidization ability of PAN-ACF increases and it increases gently above 5 %. For the removal of SO2, as the percentage of volume concentration of H2O increases, the removal efficiency falls after rising and 8 vol. % is perfect. For NO, the percentage of volume concentration of H2O is unfavorable for the removal effect.When NO and SO2 was co-existed, NO enhanced the adsorption of SO2 and SO2 suppressed the adsorption of NO. In the reaction, adsorbed SO2 and NO created new intermediate species [(NO2XSO3)]*. This intermediate species play a catalytic role in the oxidation of SO2 to SO3 and the formation of H2SO4, so the conversion of SO2 to H2SO4 enhanced. On the other hand, this intermediate species reduced a part of NO2 to NO, so the conversion of NO to HNO3 decreased. |
