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Coal-fired oxides of nitrogen is one of the main substance of atmospheric pollution, control of nitrogen oxides is imperative. Biomass reburning technology is suited to the condition of low-cost, high efficiency of the new technology, combined with the two main themes, good technical advantages and prospects for the development of energy-saving and emission reduction. Were selected with the typical characteristics of the six kinds of wheat straw, corn stalks, cotton stalks, Indus wood, pine, poplar biomass as a reburn fuel. First distinguish between herbaceous and woody plants, study the basic nature of the characteristics of the pyrolysis and combustion characteristics found: biomass generally low levels of S, N, own atmospheric pollutants generated by burning less. Lower biomass C element content, the H element content, lower calorific value. The six kinds of biomass volatile content is high, and in 62% or more, easy combustion. Biomass ashes contain a variety of active alkali metal salts, with the promotion of the role of denitrification. The mass loss rate of biomass pyrolysis and combustion processes in the pyrolysis temperature, ignition temperature, combustion temperatures are lower than coal, is the ideal reburn fuel. Although the volatilization of the woody plant, fever volume higher than the herbs, woody plants the temperature of the pyrolysis and combustion temperatures are higher than the herbs about 30 ° C, the combustion is relatively difficult. Basic reburning biomass reduction of NO were studied, the results showed that: six kinds of biomass are ideal reburning fuel, can achieve the effect of about 65% to 70% of denitration. Different fuel denitrification efficiency differences, straw, cotton stalk, pine wood, Indus denitrification efficiency higher removal efficiency of more than 67% can be achieved. A variety of factors affecting denitrification efficiency optimum range. The higher the reaction temperature, the higher the efficiency of the denitration, but the temperature is higher than 1300 ° C, a large number of thermal NOx generated, the optimum temperature is selected at 1000 ° C to 1200 ° C; reducing atmosphere, the stronger the smaller the excess air coefficient, but easy to form incomplete combustion, excessively large would cause the oxidation of the CH group, the excess air coefficient recommended selected in the 0.7 to 0.8; reburning more hours to reach the required reduction of NO CH radical concentration, reburning combustion ratio is too large will cause efficiency lower recommend a reburn than 20%; residence time causes the reduction reaction completely, but limited by the actual reaction space, select residence time in the 0.7s to 0.8s. The study found that the particle size of the fuel denitrification effect essentially no effect. The denitrification capacity biomass volatile content and pyrolysis characteristics, the results of the combined effect of the combustion characteristics and other factors woody plants and herbs denitrification capacity comparable characteristics of biomass pyrolysis temperature characteristics of the denitrification greater impact. The mixed biomass same better reburn fuel the denitration efficiency was slightly lower than the theory of a variety of biomass off denitrification efficiency average, suitable for industrial applications. Advanced reburning denitration investigated 6 kinds of biomass can reach about 81% to 90% of the effect. Different fuel denitrification efficiency differences, straw, cotton stalk, pine wood, Indus denitrification efficiency higher removal efficiency of more than 86% can be achieved. A variety of influence factors of advanced reburning denitrification efficiency optimal range. The reaction temperature is too low, ammonia agent involved in the reduction reaction rate is too low above 950 ℃, NH ,, 3 begins to oxidize generate NO, optimum temperature is selected at about 1000 ℃. A reduction reaction of the low excess air factor is not conducive to ammonia agents, too high will cause the oxidation of ammonia agent, the excess air coefficient is selected in the 0.7 to 0.8. Ammonia than the low reached less than ideal denitrification efficiency too high ammonia slip cause secondary pollution, recommended to select between 1.5 to 2. The advanced reburning Test, reburning denitration performance and ammonia agent definite synergistic characteristics. I.e. Ammonia denitration in basic reburning less efficient, exhibit high denitration efficiency; in basic reburning higher efficiency, ammonia agent denitration efficiency is relatively low. The ultimate effect of both collaborative denitration performance is basically the same for different biomass advanced reburning denitrification efficiency. The advanced reburning the effect of the additives can be effectively increased, expanding the temperature window for the reduction reaction, and a suitable temperature can be selected between 950 ℃ ~ 1100 ℃. The test Na 2 CO 3 , K 2 CO 3 , (CH 3 COO) the 2 Ca, FeCl 3 synergistic successively reduced, the top 3 can achieve more than 91.4% of the denitration efficiency; Na, K, Ca, Fe salt the denitrification capacity performance class family, Na salt, K salt synergistic promote capacity the internal MCl, the MNO , 3 the M 2 CO 3 and MOH (M = Na / K) synergistic ability to turn higher. Na salts, K salts, Ca salts, Fe salts family synergistic ability sequentially reduced.
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