In recent times environmental aspects have shown growing concern in all spheres of human-activity. Much international legislation have been passed and ratified towards more stringent pollutants emission standards, hence, there is a strong need for Power Plant operators worldwide to reduce the flue gas emission levels. Large and small power plant have to bring down the NOx emission levels to at least 150 mg/m3 (for solid fuels) to meet the air quality standards for the population and the environment.

For this reason, every effort is being made to reduce NOx emission by using various retrofitting measures. For upcoming power plants one should look for the best design for combustion and its removal in the post combustion stages.

In the present work, various NOx formation mechanism have been studied in details along with its control technique. Simulation of NOx formation in steam generator along with combustion aspects have been investigated through CFD package for different quality of coals. Parametric study of NOx emission have been simulated with the variation of various operating parameter. Future scope of this work has also been explored.