Liquefied petroleum gas or better known as LPG is a fuel and flammable gas commonly used by Indonesians for household consumption such as cooking. The combustion process of LPG has negative effects on ecological life if accumulated for a long period of time as it contributes to CO2 accumulation and climate change. Ammonia can be used in the substitution of fuels such as LPG and as an alternative energy source for the future because of carbon-free fuel and environmentally friendly combustion. The current study investigates the effects of ammonia as the carbon-free fuel in the LPG using an external premixed combustor under stoichiometric fuel mixtures. Volumetric ratios of 0%–50% between LPG and NH3 were investigated to understand the effect of replacing LPG with NH3 on flame characteristics. Oxygen was used as the oxidizer to exclude nitrogen, which is an inhibitor of flame reactivity. A high-speed camera was employed to capture the flame propagation, and the recording was processed to determine the flame characteristics of the mixtures. The experimental results show that ammonia influence on the flame height, flame angle, and dimensionless flame height normalized by the nozzle diameter. A larger replacement of ammonia resulted in a shorter flame height and larger flame angle.
