In the electron beam process, elect

In the electron beam process, electrons are accelerated by high voltage in the vacuum, and then injected into the reactor through a thin film window (Ti foil). During ionization by the electron beam, ionized electrons are generated to produce the plasma that can remove various types of contaminant molecules, such as NOx, SOx, and VOCs. Fig. 4 shows the principle of flue gas treatment using electron beam [78]. When the electron beam is irradiated, the generated primary electrons penetrate the target substance through interaction with the material, and impart energy to the substance. The energy given to a substance causes excitation or ionization of the molecule that causes the chemical reaction [34,107]. Therefore, when the electron beam is irradiated to the flue gas,the primary electrons ionize the gas component, and a series of reactive species and secondary electrons are formed [5,34,108]. The radiation chemical yields (G-value: the number of molecules or ions generated or destroyed per 100 eV absorbed ionization energy) of N2, O2, H2O, and CO2 were summarized by Mätzing [109] and given below: