Research On Iron Complex Denitration And Solution Regeneration

The pollutants emitted by the combustion of fossil fuels are the main cause of air pollution at present,and the nitrogen oxides emitted by the combustion process cause harm to the ecological environment and human health.As one of the wet denitration technologies,complexed denitration has the advantages of fast denitration rate and simple operation compared with dry denitration.In this paper,ammonium ferrous sulfate,disodium ethylenediamine tetraacetate and sodium citrate were used to establish a mixed absorption system in a small absorption tower.The experimental results show that with the increase of pH?temperature,the NO removal efficiency increases first and then decreases,and the denitrification efficiency decreases gradually with the increase of oxygen content.The optimum absorption and denitrification conditions are oxygen content 2%,reaction temperature 45?,initial pH=5 of solution,liquid-to-gas ratio is 10,NO maximum removal efficiency reaches 88%.Then the metal powder was used to reduce and regenerate the complexing agent,and it was found that the reduction effect of the metal powder was zinc>iron>aluminum in turn As a reducing agent,zinc powder can not only reduce oxidized Fe?III?L but also reduce complexed products Fe?II?L-NO.and the primary and secondary factors affecting the reduction effect were zinc powder concentration,solution pH,temperature and reaction time in turn.As the concentration of zinc powder increases,the solution pH decreases,the reaction time is prolonged,and the reduction efficiency increases gradually.When the concentration of zinc powder is0.08 mol/L,the solution pH=2 and the temperature is 40?,the regeneration efficiency of the solution reaches 80%.Finally,the specific technological dimensions of the packed absorber are calculated.The gas velocity of the air tower is calculated by the gas velocity method of the flooding point.The results are as follows:u=2.52 m/s;thus the tower diameter D=0.9m was further obtained;and the desorption factor method is used to obtain the N_OG=3.60.The calculated mass transfer unit height H_OG=0.572 m,so the calculated height of the packing layer is 2.5 m,the absorption tower height is 7.5 m.The tower top height,tower bottom height and group base height of packing layer are designed and explained.Calculated pressure drop of 4905 Pa.in packing laye.The above calculation results and experimental data can provide theoretical guidance and experimental support for the application of solution flue gas denitrification and solution regeneration integrated process.