Reduction of Emissions from a Syngas Flame Using Micromixing and Dilution with CO2

Abstract

Micromixing injection combustion is an effective low-NOx combustion technology, but a high wall temperature near the burner nozzle exit is detrimental to the nozzle and will affect burner safety in this technology. In this paper, CO2 dilution and micromixing injection combustion were combined to try to reduce NOx emissions and lower the wall temperature near the nozzle exit. Several experimental results for flames with a thermal power of 20 kW are reported as follows: the wall temperature near the nozzle can be lowered effectively by CO2 dilution combustion. The more diluent there is, the lower the wall temperature near the nozzle exit can be. Both low NOx and CO emissions can be achieved at the same time. By adjusting the combustion parameters, NOx emissions can be reduced to 2 ppm (15% O2), and the CO emissions can be reduced to 3 ppm (15% O2). In terms of the relationship between NOx and CO emissions and diluents, more diluents can lead to lower NOx emissions but can increase the CO emission. The hydro...