PREMIXED AMMONIA-METHANE-AIR COMBUSTION

ABSTRACT

The burning velocity and combustion products of premixed ammonia-methane-air flames at room temperature and pressure were measured using an adiabatic flat flame burner, and also simulated using CHEMKIN, for equivalence ratios of approximately 0.5 to 1.5 and for ammonia concentrations of 0% to 5% by volume in the fuel. Concentrations of NO, NO₂ and CO were quantified using an electrochemical gas analyzer, while ammonia concentration was measured by wet chemical analysis. The measured burning velocities agreed well with the simulated results. The addition of 4% ammonia resulted in a 10% to 20% decrease in burning velocities. Both simulations and experiments showed that adding ammonia to methane-air mixtures results in an increase in NO concentrations, especially at stoichiometric composition, and a minimal effect on CO formation. Near the flammability limits, ammonia of less than 0.1% of the incoming amount broke through the flame.

Keywords:

• ammonia
• methane
• flat flame
• nitrogen oxides

This project was funded by the Natural Sciences and Engineering Research Council of Canada.

Notes

¹Burning velocity is defined as the speed, relative to and normal to the flame front, with which unburned gas moves into the front and is transformed to products under laminar flow conditions (Glassman, 1996).