Pre-chamber Assisted Ammonia Internal Combustion Engine: Review

Decarbonizing the transportation sector is an eminent research frontier to counter the global challenge of climate change and local pollution. The hydrogen economy is pitched as a viable short and long-term solution to mitigate these challenges. However, the low volumetric energy density of hydrogen as an energy vector has been detrimental to its wide-scale adoption. Ammonia, with multiple production routes and 1.4 times higher volumetric energy density than liquid hydrogen, presents an attractive alternative for carbon-free IC engine fuel. The challenges of low flame speed, poor ignitibility, and ammonia toxicity require considerable changes to the existing engine design for ammonia combustion. Although limited in research, the use of pre-chamber for ammonia-fuelled engines is promising due to its strong turbulence generation capability and well-distributed spatial ignition characteristics. This work reviews pre-chamber-assisted IC engines operated in single and dual fuel modes using ammonia.