Experimental Study On NO_x Emissions Reduction By Biogas Reburning

Nitrogen oxides are one of the most serious atmospheric pollutants emitted from coal-burning boilers and kilns, which will cause acid rain, acid mist and even photochemical smog. More than that, it not only causes a serious threat to the ecological environmental protection, but also can harm people's life and health. With the development of human society and the advancement of civilization, people pay more attention to environmental pollution problems. Therefore, how to reduce NOx emissions has become more and more urgent and important. Among reburning is regarded as one of the most promising de-NOx control technology for coal burning systems, which not only can improve the overall utilization level of biomass energy, but also can correspondingly reduce the total weight of NOx.This paper firstly elaborated the subject background and research meaning, and indicated that NOx emissions reduction by bio gas reburning was a significant research subject which combined the biomass energy and the environment pollution problems together. And then making an in-depth research on the pyrolysis characteristics of soybean straw and corn straw, the results found that both of the biomass straw all experienced four different pyrolysis stages; with the increase of heating rate, weight loss and weight loss rate curves all moved to high temperature region, and both DTG and DSC values also significantly increased; the proper amount of K2CO3 was conductive to the pyrolysis of cellulose and hemicellulose in biomass body, but K2CO3 and KCl were unfavorable to generate biochar by lignin pyrolysis.In addition, this paper also studied the effects of final pyrolysis temperature and catalyst on the forming rules of gas components in straw pyrolysis. For soybean straw and corn straw, the volume content of CH4 in gaseous product reached the maximum value at 600?, and with the increase of pyrolysis temperature, the volume contents of H2 and CO in gaseous product were all increased. For soybean straw,5% K2CO3 was conductive to increase the volume content of H2 in gaseous product. However, with the increase of K2CO3 content, the volume content of H2 was decreased. For soybean straw, K2CO3 was unfavorable to the formation of H2 in gaseous product. On the contrary, KCl could increase the volume content of H2 in gaseous product.Finally, in the self-designed reburning experiments device, studied the effects of biogas components, stoichiometric ratio, reburning temperature, NO initial concentration on the reduction of NO. The results showed that CH4 played a vital role in the reduction of NO in the process of biogas reburning, H2 second, and CO was the weakest; at the same reburning temperature, reduction efficiency by biogas reburning reached maximum when X= 0.6, and then decreased with the increase of ?; at the same ?, with the increase of reburning temperature, reduction efficiency by biogas reburning behaved a trend of first increased then decreased; additionally, increasing the initial input concentration of NO in reburning zone, it also could make the reduction efficiency of NO by biogas reburning increased obviously.