The salient fundamental factors that influence the design of low NOxburners and of NOxabatement schemes are reviewed. They have been examined through laboratory combustor studies, which simulate some of the salient features of practical systems, while still preserving flexibility and the ability to extract mechanisms. These studies have shown that coal ignition properties and flame attachment to the burner have great influence on coal nitrogen convention to NOxin axial turbulent diffusion flames. They have also shown that distributed air addition is more effective at reducing NOxformation than simple air staging, and these results conform to field data from full scale applications