Plasma Desulfurization And Denitrification And Its Application In The Study Of Marine Diesel Engine Exhaust Treatment

This paper analyzes the more effective methods at home and abroad about SCR and wet scrubbing, which respectively aim at the removal of NOx and SOx. Probes into the study of plasma desulfurization and denitrification simultaneously. Propose a technological of combine spray humidification, plasma oxidation with sea water scrubbing apply to marine diesel exhaust desulfurization and denitrification simultaneously. This process utilizes a plasma reactor to produce oxidizing substances such as oxygen free radicals, superoxide hydrogen and hydroxy after the marine diesel exhaust has humidifying and supplementary air. By this way, SO2and NO is oxidized to sulfuric acid and nitric acid, and then removed by sea water scrubbing.We do the research about simulating flue gas desulfurization and denitrification in the laboratory on the topic of plasma oxidation. In the condition of trace O2, experiment comparative research the influence of presence or absence of water vapor, the power characteristics on non-thermal plasma desulfurization and denitrification effect. The results are as follows:(1)the drying gas stream, the removal rate of SO2reduce as its concentration increase in the entire mixed gas. The removal efficiency of SO2is about14%to28%.(2) contains a small amount of water vapor in the gas mixture. The removal rate of SO2reduce as its concentration increase in the entire mixed gas. The removal efficiency of SO2is about25%to45%. The amount of NO and NO2after reaction is more than in a dry gas stream. The initial concentration of NO in the gas distribution system is230ppm. After the reaction, its concentration remains230ppm as well. On the whole, it does not show the removal effect on NO. Within the scope of the low humidity, SO2removal rate increased significantly.(3)As the voltage increases, the efficiency of plasma desulfurization and denitrification increase. Voltage from180V to240V, the removal rate of SO2is not increase as the voltage has changed a lot, it maintains at around35%. The concentration of SO2has been around140ppm. But the concentration of NO and NOx is rising. Combined the oxidation technology with wet scrubbing, we do the research on the real marine diesel exhaust desulfurization and denitrification synchronously which under the condition of supply oxygen and increase its humidity. Test results are as follows:Fully open when the plasma power supply, do not supply air and increase its humidity, turn on the wet scrubbing installation, the NO removal rate is only about30%, the SO2removal rate can exceed85%; When the plasma power all open, supply air until the oxygen content up to17%, add a humidification water, turn on the wet scrubbing installation, the NO removal rate can exceed70%, the SO2removal rate can exceed90%.The results laid a foundation for the realization of marine diesel exhaust simultaneous desulfurization and denitrification which combined plasma oxidation with sea water scrubbing.