The emission of nitrogen oxides has a great environmental impact. It leads to Los Angeles type smog, and it recently has attracted attention as a source of ultrafine dust. The main sources of nitrogen oxides are internal combustion engines and industrial boilers. These emission sources are processes that are essential for human industrial activities, so the regulation of original use is impossible. Therefore, special control methods should be applied to reduce NOx emissions into the atmosphere. In this study, we investigated how the supply of ER and urea influences the removal of nitrogen oxides from SRF combustion boilers. Experimental results show that the removal efficiency of nitrogen oxides can be up to 80% under the conditions of ER 2.0 and a urea feed of 0.5 LPM.

This study was conducted to evaluate the emission characteristics of air pollutants from incineration facilities in Jeollanam-do. We selected 8 incineration facilities depend on type and the 19 items such as dust etc. were measured at the measurement hole for emission gas from air contamination control units. The range of emission concentrations for dust was 2.8 ~ 20.9 mg/Sm3 less than permissible air discharge standards. The results of 10 gaseous contaminants such as SOx was less than permissible air discharge standards. The range of emission concentrations for NOx was 13.4 ~ 120.0 ppm, less than permissible air discharge standards. As G facility was 112.4 ppm, 120.0 ppm, it exceeded emission standard (100 ppm) twice. The range of emission concentrations for HCl was ND ~ 85.300 ppm, B Facilitiy exceeded emission standard (20 ppm) as 85.300 ppm. The range of emission concentrations for NH3 was ND ~ 76.333 ppm, A, D, H Facility exceeded emission standard (30 ppm). The concentration of each facility was 42.416 ppm, 62.930 ppm, 76.333 ppm. The results of heavy metals (5 items) showed within emission standards. G facility is operating in condition that input of urea is 100 L/day. If input of urea were changed to 50 ~ 75 L/day, the operating cost of air pollution prevention facility can be reduced by 25% ~ 50%. In this study, the correlation between urea input and nitrogen oxides was statistically significant, but the correlation between urea input and ammonia showed insignificantly. Our research attempts to evaluate the emission characteristics of air pollutants from incineration facilities and to institute a reduction plan, an effective management of incinerators.

Nitrogen oxide (NOx) is one of air pollutants generated from the combustion of fuels, causing serious environmental problems. A novel externally oscillated staged combustion for RPF syngas was proposed in this work. The staged combustion could reduce NOx by the fuel-rich state combustion, while the external oscillation could achieve complete burn-out by stabilizing the flame. It also improved combustibility with an acceleration of the mass and heat momentum transfer. Parametric studies were achieved for the NOx reduction characteristics on the air staging and fuel staging in each case of with or without external oscillation. For the case of without oscillation, NOx reduction rate for the fuel staging had higher value as 75% than air staging as 67%. However, an application of external oscillation for both cases gives higher NOx reduction rate of 79%. The optimal condition for the oscillated fuel staging was that the air ratio in main burning zone, reburning zone and burnout zone were 1.1, 0.6 and 1.15, respectively, having 200 Hz of external oscillation.

The SCR (selective catalytic reduction) system is highly-effective technique for NOx reduction from exhaust gases. In this study, the effects of the direction and size of nozzle and the ammonia injection concentration on the performance of SCR system are analyzed by using the computational fluid dynamics method. When the nozzle is arranged in zigzaged direction which is normal to exhausted gas flow, it is shown that the uniformity of gas flow and the NH3/NO molar ratio is improved remarkably. With the change of the ammonia injection concentration from 0.2 vol%(wet) to 1.0 vol%(wet), the uniformity of gas flow shows a good results. As the size of nozzle diameter changes from 6 mm to 12 mm, the uniformity of gas flow is maintained well. It is shown that the uniformity of the NH3/NO molar ratio becomes better with decreasing the ammonia injection concentration and the size of nozzle diameter.

V2O5/TiO2 catalysts promoted with Mn were prepared and tested for selective catalytic reduction of NOx in NH3. The effects of promoter content, degree of catalyst loading were investigated for NOx activity while changing temperatures, mole ratio, space velocity and O2 concentration. Among the various V2O5 catalysts having different metal loadings, V2O5(1 wt.%) catalyst showed the highest activity(98%) under wide temperature range of 200-250℃. When the V2O5 catalyst was further modified with 5 wt.% Mn as a promoter, the highest activity(90-47%) was obtained over the low temperature windows of 100-200℃. From Mn-V2O5/TiO2, it was found that by addition of 5 wt.% Mn on V2O5/TiO2 catalyst, reduction activity of catalyst was improved, which resulted in the increase of catalytic activity and NOx reduction. According to the results, NOx removal decreased for 10%, but the reaction temperature down to 100℃.