The Liquid Absorption Of NO And Comprehensive Utilization Of The Liquid

The emissions of NOX have caused a series of environmental problems such as acid rain, haze, ozone thinning, and photochemical pollution etc. which bring a great impact on people.The liquid absorption is a method to removal NO which is widely studied, especially for removaling NO by complex absorption. and a variety of absorbing liquid have been studied to date. However, the difficulty of recycling the absorption liquid limits the application of this method. In order to resolve these problems,we use FeSO4、Fe"EDTA to removal the NO in flue gas by the way of complexation, and circulating utilization was also discussed at the same time.In this paper, a two-step method was employed to removal the NO in flue gas, first we fixed NO with the absorbing liquid by the way of complexation, and then NO can be oxidized to NO3- by H2O2. In the experiments, some factors which may affect Fe"EDTA absorbing NO and further oxidating NO to NO3- were studied such as the pH of the absorbing liquid, concentration, temperature, the amount of H2O2 and so on. Studies have shown that when we use FeⅡEDTA (0.13mol/L) to absorb NO and add H2O2 as the oxidizer later, the concentration of NO3-is 0.1086 mol/L, the oxidation efficiency of NO can reach 83.54%; when we use FeSO4 (0.01mol/L) to absorb NO and add H2O2 as the oxidizer later, the concentration of NO3 is 0.0041 mol/LMeanwhile, the recycling of the Fe EDTA solution was also studied. In order to regenerate the absorption liquid which absorbed NO and oxidized by H2O2, we adjust the pH of the solution to 5.0, add Fe to deoxygenate FeⅢ to FeⅡEDTA so that it can keep on absorbing NO. After five recycling of the absorption liquid EDTA, molysite, etc. can be recovered by adjusting the pH to achieve comprehensive utilization, and the recovery rate of EDTA is 93.1%. In addition, product of Fe(OH)3 can be used to prepare iron oxide pigments after calcining at 600℃ for 1h.Our study provide a new method to regenerate the absorption liquid, and the lower costs of regeneration make the industrial application of this method possible.