Research On The NO_x Removal From Automobile Exhaust By Non-thermal Plasma

Rapid development of the automobile industry has led the rapid economic development, but has inevitably caused the serious pollution to the environment. The vehicle emission regulations are being stricter today, controlling of the vehicle emissions has become the extremely urgent duty, diesel engine emissions prominently, and it is the difficult point in the domain of controlling the vehicle emissions also. This article proposed an experiment system using non-thermal plasma processing simulated automobile exhaust. And in this paper, the model of chemical kinetics for the automobile exhaust control using non-thermal plasma is carried out. By analyzing this model, we have discussed the kinetic characteristic of emission control. Main research contents as follows:1. In-cylinder purification technologies and after-treatment technologies were analyzed for reducing the engine emissions, knowing that the after-treatment devices which the engines currently used cannot simultaneously process NO_x, PM and CH in the automobile exhaust effectively .It was also analyzed present situations and the superiorities that using non-thermal plasma technology processes automobile exhaust.2. Conversion mechanisms and influence factors of using non-thermal plasma technologies processing NO_x in the automobile exhaust were induced, which can provide the theory basis for designing non-thermal plasma generator, and can provide the foundations for simulating conversion mechanisms.3. On the basis of dielectric barrier discharge theory, a plasma experimental device was designed. The treating of simulated exhaust by non-thermal plasma was studied via experiment. The influence of the discharge voltage, the resident time of the simulated exhaust in the DBD reactor, the initial concentration of NO and the exist of oxygen and ethene were detected in the course of NO_x removal.4. The possible reaction approaches of NO_x removal from automobile exhaust by non-thermal plasma were analyzed, from which the main reactions in the simulated exhaust were selected. A kinetic model is established; it is solved with MATLAB programming, and carried on computer simulation. We found that the kinetics figure was consistent with the experiment data. Thus the reaction mechanism can be proved to be reasonable. The reaction kinetics of the rest main composition in the simulated exhaust was forecasted by the kinetics model.