Studys On Removing Nitrogen Oxides By Dielectric Barrier Discharge Plasma

With the rapid development of global economy and society currently, environmental pollution, especially atmospheric pollution, is becoming more and more serious. Nitrogen oxides, as one of the major atmospheric pollutants, not only are harmful to health and survival of human, animal and plant. But also can form acid rain and photochemical smog which damage to the ecological environment. Therefore, the control and governance of nitrogen oxides has become one research hotspot in recently years.Compared with other nitrogen oxide treatment technology, plasma technology has many advantages such as small footprint, low investment, no secondary pollution, low operating costs, no corrosion to equipment and so on, so the study on the plasma treatment for nitrogen oxides has very important practical significance. This paper studied two kinds of dielectric barrier (DBD) reactor which designed by myself:double dielectric barrier reactor and line-drum reactor.Experimental results from double dielectric barrier discharge reactor are shown as follow:1. The experiment to design a double dielectric barrier discharge reactor; By distribution of laboratory gas, the influence of different reaction conditions on the removal rate of nitrogen oxides was investigated under the atmosphere of N2/O2/NO.2. The peak voltage, oxygen content, initial concentration and gas flow effects on NO and NOx removal rate. When the voltage ranges from14kV to21kV, NO and NOX removal rate increases with the increase of voltage. NO and NOX removal rate presents a downward trend with the increase of oxygen content which is lower than1.8%, especially for NOx removal rate. In the range of600-1600ml/min, NO and NOX removal rate increased with the increase of gas flow.3. In this article, three experimental processes, in which there were different gases ((1) O2,(2) O2and N2,(3) O2N2and NO) went through plasma, were designed to examine the influence of O3generated by plasma on the removal of nitrogen oxides. And, when O2alone go through plasma, its flow has little effect on NO removal rate.4. The filler effect on NO and NOX removal rate. The influence of filler including ceramsites with different sizes and catalysts made by myself on the removal rate of nitrogen oxides was studied. And the studies show that the bigger the ceramic particle size is, the more advantageous for NO and NOx removing; ZSM-5loaded Cu is more conducive to NO and NOx removing than ZSM-5loaded nothing.For line-drum reactor experimental results show that: 1. The influence of the oxygen content. Study the impact of input voltage on NO and NO2concentrations without NO input and with NO input. Results show that without NO input the amount of NO increased with the increased of voltages and O2concentrations. And NO2concentration increased significantly at the starting voltage.2. The initial concentration and gas flow effects on NO and NOx removal rate. The removal rate of NO and NOx decreases with the increase of gas flow when the gas flow (400-1600ml/min) and initial concentration (100-2000ppm).3. The electrode size and pipe diameter effect on NO and NOX removal rate. We used tungsten electrodes with a diameter of1.2,2.5,3.1mm and tubular reactors with a diameter of15,20,25mm were used. And, the removal rate of NO and NOx increases with the increase of electrode size and the decrease of tubular reactor diameter. But the removal rate of NOx is low with low NO concentration by tubular reactor with smaller diameter.