Reducing NOx emissions in tangentially-fired boilers-a new approach

Nitrogen Oxides Emission Control Options for Coal-Fired Electric Utility Boilers

“…Reductions with OFA range from 20% to Ͼ60% depending on the initial NOx levels of a boiler, fuel combustion equipment design, and fuel type. 23 However, while reducing (substoichiometric) conditions result in significant NO X reduction, increased levels of UBC and CO can occur. The extent of these increases is dependent on the design of the OFA system and fuel properties.…”

“…24 Recent experience reflects that the application of OFA on tangentially fired boilers can provide NO x reductions in excess of 50%, with moderate (25-35% from baseline) increases in UBC levels and CO emissions of Ͻ50 ppm (corrected to 3% O 2 ). 23 Primary control technologies, described above, have been widely implemented on U.S. coal-fired utility boilers to comply with the NO x emissions reduction requirements of the Title IV NO x Program. Table 1 provides a summary of primary control applications through 2003.…”

Numerical Simulation of the NOx Emissions in a 1000 MW Tangentially Fired Pulverized-Coal Boiler: Influence of the Multi-group Arrangement of the Separated over Fire Air

“…5,18 Under the OFA operation, the temperature of the burner zone will be reduced and NO x can be changed to N 2 in the fuel-rich region in the furnace. 19,20 Liu et al 11 investigated the influence of the OFA position on the NO x emissions. They found that the NO x emissions can be greatly reduced with less influence on combustion efficiency by adjusting the OFA position.…”

Using a genetic algorithm and CFD to identify low NOx configurations in an industrial boiler

“…The main objective of these technologies is to minimise the reaction temperature and the contact between nitrogen from the fuel and oxygen present in the combustion air, while creating a fuel-rich area where NO x can be reduced to N 2 [1][2][3][4][5][6][7]. Since NO x emissions are strongly related to complex physical and chemical processes such as turbulence, combustion (pyrolysis, homogeneous and heterogeneous oxidation), heat transfer, radiation, and NO x formation/destruction mechanisms, understanding these complex processes is a prerequisite to reducing NO x emissions.…”