Reduction and Control Technologies

Overview
Principles of NOx Reduction
Fuel Switching
Combustion Control
Flue Gas Treatment
Fuel Reburning
Choosing the Best NOx Technology for the Job
Summary and References

Fuel Switching

The graph below illustrates the relationship between relative NOx emission levels and fuel-bound nitrogen content.

Because fuel-bound nitrogen plays such an important role in total NOx emissions from fuel combustion in boilers, switching from high-nitrogen fuels, such as residual oil to lower nitrogen fuels such as natural gas, can be an effective strategy. As an example, switching from residual oil with 0.6% nitrogen to natural gas can result in a 50-80% reduction in NOx emissions. In addition, SO2 emissions are eliminated.