Research On The Removal Of NO With Cobalt Diethylenetriamine

Nitric oxide can be removed with cobalt diethylenetriamine by complexing NO in the solution.Cobalt diethylenetriamine is an innovative complex,it shows great potential of removing NO,which reflects possibility of the application in industry.Aside from the concentration of[Co?dien?₂]²⁺,the proportion of Co²⁺ and diethylenetriamine,the pH value,the temperature,the effect of oxygen content in flue gas and concentration of impurities on the gas-liquid absorption of NO were investigated.The equilibrium constant was determined in non-oxygen absorption of NO in[Co?dien?₂]²⁺ solution,the thermodynamic functions was determined accordingly.The absorption of NO won't remain in high removal on account of the fact that Co²⁺ would be transferred into Co³⁺,and[Co?dien?₂]³⁺is not an exact chelate of NO.Activated carbon was used as a catalyst in the conversion of Co³⁺ to Co²⁺.After the treatment with acetic acid and calcined in a furnace,activated carbon was put in[Co?dien?₂]³⁺ solution to research the effect of different factors on the conversion of[Co?dien?₂]³⁺.The carbon mesh?the amount of carbon added in each batch?the temperature?pH value?the concentration of[Co?dien?₂]³⁺?the concentration of impurities WGau considered as factors in the conversion of[Co?dien?₂]³⁺ to[Co?dien?₂]²⁺.The optimal absorption condition can be got from experiments as follows:T=50?,c(Co²⁺/diethylenetriamine)=:2,pH=6.5,c(Co²⁺)=0.04mol/L,oxygen proportion in simulated mixed gas 5%.In addition,the NO removal efficiency decreases when large amounts of NO₂^-and SO₃^2- exist in the absorbent.Na+and K+ ions have no impact on the NO removal.The NO removal efficiency increases in certain concentration of SO₄^2-,while the removal efficiency decreases as the concentration is higher than certain value.The NO removal efficiency increases as the concentration of NH₄^?increases,which suggests NH₄⁺facilitate the absorption of NO.The equilibrium constant was determined in the temperature range 33??70 ?,all experimental data fit the equilibrium constant equation well:Kp=1.905×10-exp{20590.19/T}?bar-1?The experimental results show that the reaction is spontaneous and exothermic with a entropy decrease.The conversion efficiency can reach 35%when activated carbon was added into[Co?dien?₂]³⁺ solution,the optimal reduction condition is as follows:pH=3,T=90 ?,carbon mesh 100?120,2g activated carbon added in solution,c([Co?dien?₂]³⁺)=0.01 mol/L,...