(393f) Numerical Simulation of Fuel NOx and Thermal NOx Emissions from an Industrial Burner Using Biomass-Derived Producer Gas

Most of the industrial burners in the market are designed for natural gas or synthesis gas resulting from coal gasification. These burners are optimized to reduce the thermal NOx emissions but often do not address the fuel NOx problem. On the other hand, producer gas derived from biomass gasification contains traces of ammonia. Combustion of such producer gas results in high emissions of NOx due to the significant amount of fuel NOx in addition to thermal NOx. In this study we performed modeling of an industrial burner to analyze NOx emissions resulting from combustion of biomass-derived producer gas.  Multidimensional CFD modeling of the burner was performed initially using a detailed mechanism, and the results were validated using the experimental results. However, such a detailed mechanism is highly computationally intensive to be used with 3D modeling. Thus, the detailed mechanism was reduced to a skeletal mechanism, without loss of accuracy in NOx prediction. Further CFD modeling of the actual burner geometry were conducted and results were validated using experimental data. The relative ratios of thermal NOx and fuel NOx are characterized under different operating conditions. The resulting skeletal mechanism and modeling strategies can be used in the future as a tool to design low-NOx burner using producer gas containing ammonia.