Experimental Investigation of Minimum Achievable Nox from Low Carbon Fuels

Low carbon fuels face growing interest as the power generation and transportation fields embrace decarbonization. However, low carbon fuels may still introduce pollutant emissions challenges. Hydrogen and ammonia are two popular decarbonization fuels that face public scrutiny over potential NOX emissions. However, much of this scrutiny is grounded in unscientific roots, including experiments with improper control parameters or demonstrations with legacy hardware that are not appropriate comparison tests for these fuels. Therefore, EPRI and the Zinn Combustion Lab at Georgia Tech have conducted a series of chemical kinetic simulations and experiments with both hydrogen and ammonia to examine NOX emissions from direct combustion of these fuels with a target of dry, low NOX comparisons. The calculations were conducted to determine burner architectures that promise low NOX potential and fuel flexibility, as well as to predict the minimum achievable NOX (NOX entitlement). The experiments were conducted to validate the calculations and to provide first-ever demonstrations of a new fuel flexible, low NOX burner concept designed for these decarbonization fuels. This paper will present the promising calculations and experimental results. The results show hydrogen NOX emissions similar to natural gas combustion, and low double digit NOX concentrations from direct ammonia combustion.