@article{0a1d6db4-fbe2-4b34-9766-02d40f0d3749,
  abstract     = {{<p>Ammonia/diesel dual-fuel compression-ignition engines are a promising solution for reducing carbon emissions in marine applications, yet their combustion efficiency and nitrogen-related emissions remain major challenges. In this study, combined numerical simulations and experiments were performed to investigate combustion characteristics and emissions in a two-stroke, low-speed ammonia/diesel direct-injection engine operating at low load (IMEP up to 3.7 bar), with ammonia energy ratios (AER) ranging from 0% to 49%. The results show that increasing ammonia substitution significantly reduces the emissions of conventional pollutants, with NO <sub>x</sub> emissions decreasing by up to 42% and CO emissions reduced by approximately 80–92% compared to diesel-only operation. However, N<sub>2</sub>O emissions increase dramatically with ammonia addition, rising by more than two orders of magnitude, which leads to an overall ∼150% increase in total greenhouse gas (GHG) emissions despite the reduction in CO<sub>2</sub>. Analysis of incylinder processes indicates that ammonia ignition relies on its engulfment by the diesel flame, while ammonia–diesel spray interaction governs combustion completeness, ammonia slip, and N<sub>2</sub>O formation. These findings highlight the trade-off between NO <sub>x</sub> reduction and N<sub>2</sub>O-induced GHG penalties in ammonia/diesel dual-fuel engines and underscore the importance of injector configuration and in-cylinder flow optimization for mitigating N<sub>2</sub>O emissions.</p>}},
  author       = {{Xu, Leilei and Miccio, Margherita and Dong, Pengbo and Zhang, Zhenxian and Long, Wuqiang and Bai, Xue Song}},
  issn         = {{0016-2361}},
  keywords     = {{Ammonia; Ammonia and diesel injection; Decarbonization; Greenhouse gases (GHG); Marine engine}},
  language     = {{eng}},
  month        = {{10}},
  publisher    = {{Elsevier}},
  series       = {{Fuel}},
  title        = {{Combustion and emission characteristics in a two-stroke direct-injection compression-ignition ammonia/diesel dual-fuel engine}},
  url          = {{http://dx.doi.org/10.1016/j.fuel.2026.139142}},
  doi          = {{10.1016/j.fuel.2026.139142}},
  volume       = {{422}},
  year         = {{2026}},
}