Numerical analysis of effects of iron pentacarbonyl as fuel additive for reducing NO and soot precursors from methane/air diffusion flame

The present work focuses on improving our understanding of interactions of as-produced iron species, from thermal decomposition of iron pentacarbonyl during combustion, and major gaseous emissions from a methane/air counter-flow laminar flame. Numerical simulation explores underlying issues which are, otherwise, difficult to analyze by experimental means. Sensitivity analysis is carried out to investigate the influence of input parameters such as iron pentacarbonyl concentration and fuel fraction on emissions. Results demonstrate a proportional decline in most C2Hx, commonly accepted soot precursors, and NO species with increasing the concentration of Fe(CO)5. The decline in NO and C2H2 emissions is found to be more promising with increasing the fuel fraction. Beyond a certain threshold of the fuel fraction, however, the radical pool in the flame sufficiently overwhelms the additionally radical scavenging of iron species and consequently the emission reduction declines. In addition, a high flame temperature results in activation of new iron pathways which lead to a greater emission reduction.