A review of removing SO2 and NOX by wet scrubbing

Air pollution has intensified in recent years. The rates of sulfur dioxide (SO2) and nitrogen oxides (NOx) contributing to air pollution have risen annually, imposing huge burdens on human health and industrial production. Among gas separation techniques, wet scrubbing exhibits superior economical and application value to simultaneously remove SO2 and NOX. This paper summarizes the mechanism, study approaches, and application status of wet scrubbing to remove SO2 and NOX. Given the results of previous experiments, the factors are split into three categories: operating parameters, equipment parameters, and additional conditions. With the mechanism and degrees of each factor considered, a wet scrubbing optimization scheme for enhancing the absorption efficiency is presented. In order to improve the removal efficiency while maintaining sustainability, this study also introduces the method of waste heat recovery and water recycling in the wet scrubbing system. In view of the current conditions, the development trend of wet scrubbing should be optimized as well as combined with other new technologies.