Modeling and chemical kinetic analysis of methanol and reformed gas (H2/CO2) blending with ammonia under lean-burn condition

Abstract

Hydrogen can be easily produced by methanol steam reforming. This work aims to investigate the effects of methanol addition and its reformed gas of H2/CO2 on ammonia combustion under lean-burn operation. A newly-developed reaction mechanism for NH3, H2, CH3OH, CO and their blends was established based on the highly-precise validations of laminar burning velocity (LBV), nitrogen monoxide (NO) and ignition delay time (IDT). The premixed flame analysis showed that methanol blends and reforming with hydrogen addition can greatly enhance the combustion rate, resulted from the chemical effect. The equivalence ratio (ER) can be extended to 0.45 for a methanol blending ratio of 60 % and reforming ratio of 90 % (M60R90) to achieve the similar level of LBV at pure ammonia at an ER of 1.0 under ambient condition. The methanol blends and reforming lead to the increase of NO, while the lean-burn operation can help to reduce the NO emission.