Purification Technologies for NOx Removal from Flue Gas: A Review

Nitrogen oxide (NOx) is a major gaseous pollutant in flue gases from power plants, industrial processes, and waste incineration that can have adverse impacts on the environment and human health. Many denitrification (de-NOx) technologies have been developed to reduce NOx emissions in the past several decades. This paper provides a review of the recent literature on NOx post-combustion purification methods with different reagents. From the perspective of changes in the valence of nitrogen (N), purification technologies against NOx in flue gas are classified into three approaches: oxidation, reduction, and adsorption/absorption. The removal processes, mechanisms, and influencing factors of each method are systematically reviewed. In addition, the main challenges and potential breakthroughs of each method are discussed in detail and possible directions for future research activities are proposed. This review provides a fundamental and systematic understanding of the mechanisms of denitrification from flue gas and can help researchers select high-performance and cost-effective methods.

Automated summary

This paper reviews recent literature on NOx post-combustion purification methods using different reagents. It categorizes the purification technologies into oxidation, reduction, and adsorption/absorption approaches based on changes in the valence of nitrogen (N). The paper systematically reviews the removal processes, mechanisms, and influencing factors of each method, and discusses the main challenges and potential breakthroughs. The proposed review provides a fundamental understanding of denitrification from flue gas and offers guidance for selecting effective methods.