| Abstract [eng] |
Directives of pollution reducing are getting stricter, so we are in need to find effective methods to reduce NOX in the industrial boilers exhaust gases. This study presents an experimental investigation of various NOX reduction methods while burning wood panel chip pellets on industrial prototype boiler in temperature range of 1000 – 1200 °C. At the first part of the work the nitrogen oxides formation mechanisms and basic nitrogen oxides reduction methods (both primary and secondary) are briefly reviewed. The second part describes process and methodology of the research, laboratory stand and other equipment which was used during research. NOX reduction methods that were used: exhaust gas recirculation (EGR) through the furnace, steam injection to the furnace, traditional and flammable additives usage in the SNCR technology. Flammable additives used in the research: CH4, C2H2 and mixture of C3H8 and C4H10. Ammonia NH3 was selected as the traditional additive, which is mostly used in the SNCR technologies. This work assesses the influence of NOX reduction by above mentioned methods. NOX and CO concentrations in flue gas were measured during this research. Results of the experiments are shown and described at the final part of this work. Comparing the effects of additives in NOX reduction while burning furniture production waste showed that NH3 additives reduces primary NOX by 56 %. Flammable additives can reduce up to 76 % NOX emissions in exhaust gases. Exhaust gas recirculation (EGR) through the furnace or steam injection to the furnace reduces NOX concentrations only slightly. Results showed that SNCR technology with flammable additives can change traditional NOX reduction additives and this technology can be easily installed into existing boilers. |
