Study On NO_x Of Flue Wet Scrubbing

As the expensive cost, flue gas treatment was not fitted on the middle and mini typeboiler which had influenced environmental protection. In our study, the simulated flue gas asraw material was treated using wet process. Firstly, the adsorbent and catalyst were chosen,then, effects of variables of initial concentration of adsorbent and NO_x, temperature, dosage ofcatalyst, initial pH were studied. Inthe condition of investigation of variables, initialconcentration of adsorbent, temperature, dosage of catalyst and initial pH were taken asvariables and removal rate as response, and the relationship between variables and responsewas studied by using Response Surface Methodology (RSM).(1) Removal rate of distilled water, urea, NaOH and H2SO4solution was obtained, andthe date shows that the removal rate of distilled water was lowest, and the others were closed.The removal rate was decreasing as the extending of time, and the date of urea was mini. Theurea was chosen as adsorbent as a result.(2) The comparison of effect of sodium chlorite, potassium permanganate, peroxide andthin nitric acid shows that the sodium chlorite was best. The concentration of four catalystwere set as0,1.5%and3.0%, and the concentration was higher, the effect was better. Theremoval rate of potassium permanganate, sodium chlorite, peroxide and thin nitric acid wereobtained as73.2%、80.3%、76.6%and56.5%. The sodium chlorite was chosen as catalyst asa result.(3) The single factor experiments show that the removal effects were increasing first, anddecreasing afterwards, as the increasing of initial concentration of adsorbent and NO_x,temperature, dosage of catalyst, and increasing as the increasing of initial pH. The highestremoval rate was obtained as follows:3%of concentration of urea,0.005mol/L of catalyst,60℃of temperature and10of initial pH.(4) Response surface methodology (RSM) was carried to study the combined effects andinfluence of sodium chlorite concentration, temperature, initial pH, urea concentration as variables on the NO_xremoval. The response surface contour plots clearly indicated that thehypochlorite concentration、urea concentration and initial pH were main factors influencingthe rate of removal, the interactions were not influence sufficient, and the hypochloriteconcentration and initial pH of quadratic terms were significant. The satisfactory conditionswere obtained as follows:0.0057mol/L of sodium hypochlorite concentration,51.91℃oftemperature,10.33of initial pH and0.52mol/L of urea concentration. And the rate of NO_xremoval was attained at88.8%.