Removal Of NO_x With Polypropylene Hollow Fiber Membrane Contactor

Nitrogen oxide was recognized as some of the most harmful and most difficult to control of the man-made pollutants.They often arise as by-products from both stationary and mobile combustion sources.Challenges of nitrogen oxides reduction remains primarily due to the inactive nitric oxide,which accounts for 90-95%of nitrogen oxides.Development of cost-efficient denitration technologies has been a challenging task in chemical industry.Here we proposed a new denitration method by using polypropylene hollow fiber membrane contactor,through which the NO gas from a simulative flue gas was absorbed into a saline aqueous solution,and then oxidized by the added H2O2.We demonstrated that the numerous pores in the semipermeable membrane and the addition of NaCl gave rise to a high-efficient oxidation-absorption process.By using this new hybrid denitration technology,we extensively examined the effects of different operation parameters including the gas and liquid flow rates,the concentrations of H2O2 and NaCl in the solution,the absorption temperature and the circulating time.The optimal operation parameters were identified.Combining with a theoretical study upon both classical and quantum density functional theories the role of NaCl in absorption solution was investigated.Finally,along with a designed industrial flow chart we evaluated the cost-efficiency of this proposed method,and found that this method could be more competitive than the current mainstream technologies for flue gas denitration.