Control of combustion-generated nitrogen oxide emissions: Technology driven by regulation

TLDR

Nitrogen oxides from combustion contribute to smog, acid rain, ozone depletion, and global warming, and their steadily rising emissions have prompted increasingly stringent regulations that drive the development of control technologies. This review surveys current and emerging NOx‑reduction technologies and evaluates their potential to meet tightening emission standards. The technologies examined include combustion‑modification approaches and post‑combustion methods for NOx removal.

Abstract

Nitrogen oxides in the atmosphere contribute to photochemical smog, to the formation of acid rain precursors, to the destruction of ozone in the stratosphere and to global warming. Over the past 150 years, global emissions of nitrogen oxides into the atmosphere have been increasing steadily. A significant amount of the nitrogen oxide emissions is attributed to combustion of biomass and fossil fuels. Increasingly stringent NOx emissions regulations are being implemented in a number of industrialized countries. These regulations have driven and continue to drive the development of NOx emissions control techniques. This paper reviews existing and some emerging technologies for reduction of NOx emissions from combustion sources and examines the prospects of these technologies for meeting stricter emissions regulations. Both combustion modification and post-combustion methods for NOx reduction are considered. The important role of research on the chemistry of nitrogen oxides in combustion gases in development and optimization of emissions control techniques is described.