Study On Desulfurization And Denitrification Integration Control Technology From Middle And Small Coal-Fired Boiler

The pollution from point source of middle and small size boiler is not only huge amount but the pollutant total amount is large in China. There is no industrial desulfurization technology of coal-fired boiler which suitable national conditions, so it is no way to take denitrification from industrial boiler into account. Therefore, development of desulfurization and denitrification integration technology for middle and small boiler becomes a critical need in domestic market, which is small investment and easy operation.This paper put forward a desulfurization and denitrification integration control technology using NaClO₂ solution as absorbent, and sieve spray tower as reactor, which capability of flue gas treatment is 0⁴0m³/h. By analysis the oxidation and absorption of NaClO₂ and SO₂,NO, this paper researches on various kinds of parameters which impact on desulfurization and denitrification process. On the premise of sufficient removal efficiency and suitable costs, the best experiment condition is decided as following: initial pH of absorption solution is 5, temperature of absorption fluid is 50℃, liquid-gas ratio is 16 L/m³, inlet SO₂,NO concentration is 2854 mg/m³,667 mg/m³, concentration of NaClO₂ is 0.016mol/L. This will lead to the desulfurization rate around 92% and the denitrification rate above 70%.The study has developed the desulfurization and denitrification integration test device which fit for small coal-fired boiler. Through the experimental data, this paper studied the intrinsic kinetics of SO₂,NO and NaClO₂ reaction in the systematic, and established the mass transfer model and desulfurization,denitrification model. The results shows that the price of sodium chlorite is higher, but it has good comprehensive cost-effective and better denitrification efficiency, in addition, this equipment has advantages of simplified equipment and easy to reach the discharge standard. Therefore, the theoretical study of this article has a certain academic significance, it can provide a theoretical basis for further research, and this method is very important to decrease huge amount of SO₂,NO pollution from middle and small size boiler and has a broad application prospect.