Research Of The Nitric Oxide Complexing Absorbed By Fe^ⅡEDTA

In recent years, a growing number of nitrogen oxides NOxhas been more and moreseverely harmful to environment and human beings, which has become the key air pollutantmust be controlled during the12th Five Year Plan of China. As one of the main componentsof NOx, nitric oxide NO is firstly oxidized to NO2in the wet governance process of NOxbecause of its low solubility.However, NO can not be oxidized rapidly at lowconcentration,which makes the difficulty of governance greatly increased.Represented byFeIIEDTA, ferrous complexes can take the coordination reaction with NO, and then NO canbe removed directly. It is considered to be the most processing NO controlled methods due tothe fast reaction rate, the high capacity, the environmentally-friendly iron, and nonesecondary pollutants. Compared with the traditional tower equipment, high gravity rotatingpacked bed RPB has the advantages of enhanced mass transfer process and improvement ofthe production ability so on. Consequently, RPB has been widely used in a variety of wastegas treatment. Exploration of NO complexing absorption in a rotating packed has greatsignificance for the industrial application of NO wet treatment.First of all, the gas-liquid reaction characteristics of NO absorption with FeIIEDTAcomplex was investigated in the laboratory self-designed bubbling reactor. The resultsshowed that the absorption of NO by FeIIEDTAcomplex was pseudo first order rapid reactionat the experimental conditions,the average of reaction rate constant k1was calculated to be1.33×108L·mol-1·s-1,and the order of the enhancement factor E was102.In addition,theresearch determined that NO absorption process was controlled by mass transfer, and masstransfer resistance exited in liquid membrane,which laid the foundation for the study of NOabsorption in the high gravity rotating packed bed.Then,NO complex absorption process in the high gravity rotating packed bed was studied.The influence of super gravity factor, gas to liquid ratio, gas flow rate, theconcentration of FeIIEDTA, inlet concentration of NO to the removal efficiency and masstransfer coefficient of NO absorption with FeIIEDTA complex was investigated,and therelationship between the factors and effects of the total mass transfer coefficient in rotatingpacked bed was obtained.Moreover,NO absorption efficiency on the different super gravityfactor and different content of O2in a rotating packed bed was comparative studied.when noO2mixed in gas,NO absorption efficiency and total mass transfer coefficient at β=82were1.86times and2.47times than β=10respectively,which showed that RPB can certainlyenhanced the absorption of NO.And when8%O2presented in the mixed gas, NO removalefficiency decreased after120min, and NO removal efficiency fall range was12.9%atβ=82,which was far less than the decrease at β=10(74.2%).As a consequence, the rotatingpacked bed can be proved to enhance the absorption of NO effectively and suppressed theoxidation of absorbent at the same time,which provided a new thought for solving theoxidation of FeIIEDTA.