Research Of Additives In Wet Flue Gas Denitrification Technology

With the rapid development of China's economy,the air pollution problem has become increasingly prominent.Research showed that NOx produced by combustion of fossil flue is one of major pollutants in the atmosphere,so it is necessary to find a suitable denitrification methods.Wet flue gas denitrification has the advantages of low reaction temperature and the reaction products has no pollution to the environment,which has become one of the hot spots of people's research.In this paper,ozone was used as oxidant and urea solution was used as absorbent,first,the feasibility of urea denitrification reaction was studied theoretically.The denitration experiment was conducted in a self-made pilot packing tower,the effect of absorption liquid temperature,mole ratio of[O3]/[NO],pH,gas volume,circulating fluid volume,and initial NO concentration were investigated.TEA and DEA were added in urea solution to investigate the effects of different parameters on mixed system denitration efficiency.The results indicated that when mole ratio of[O3]/[NO]was 1.93:1,absorption liquid temperature was 50?,gas volume was 4 m3/h,circulating fluid volume was 800 L/h,when the mass fraction of TEA in absorption liquid was 10000 ppm,the denitration efficiency of the absorption liquid was increased by 36.32%,when the mass fraction of DEA in absorption liquid was 10000 ppm,the denitration efficiency of the absorption liquid was increased by 32.74%.The experimental study on denitrification of TEA and DEA alone showed that the denitrification efficiency of the two was much higher than that of urea alone,which was slightly lower than the denitration efficiency of the mixed system.This indicated that TEA and DEA had a weak synergistic effect with urea.TEA was added into the urea solution in the same ratio as DEA,it was found that the combined absorbent solution has higher denitration efficiency than that of TEA and DEA when they were added alone,however,with the increased of TEA and DEA,the denitration efficiency increased less obvious.When TEA and DEA were added into urea solution in different proportions,it was found that TEA(mass fraction):DEA(mass fraction)was 1:1,the denitration effect was higher than that of 2:1.Denitrification mechanism of TEA and DEA was also explored,results showed that the denitrification mechanism of TEA and DEA were similar to each other,which was almost the same as that of mentioned in literature.