A study on additives to improve electron beam technology for NOx and SO2 reduction

Abstract Electron beams are a promising technology for treating a large amount of air pollutants with high energy for a fast reaction time. For these reasons, the electron beams have been employed to control NOx (NO and NO2) and SO2 generated from stationary emission sources. In recent years, NH3 was commonly added in the electron beam process to achieve a high removal performance for NOx and SO2. However, the development of economically efficient and effective additives is still required to overcome relatively low removal ability for NOx. In this study, various experimental parameters that affect the removal efficiency of NOx and SO2 based on electron beam technology were investigated. To obtain an optimal removal efficiency, three different types of parameters such as additives, absorbed doses, and initial concentrations were evaluated. The average removal efficiency of 200 ppm NOx and SO2 was 46.7% at an absorbed dose of 20 kGy when NH4OH was used as an additive. However, the average removal efficiency (80.6%) of NOx and SO2 increased additionally up to 33.9% when the NaOH additive was added in an electron beam process. The removal efficiency of NOx and SO2 increased systematically with an increasing absorbed dose or decreasing initial concentration. Among the various experimental parameters, the type of additives was the most influential factor on the removal efficiency, especially for NOx, in an electron beam process.