A new project will develop reliable emission factors for NOx-emissions from ships

Measurements of nitrogen oxides (NOx) from ships show significantly higher levels than those reported by the vessels' engine classification systems. The project, "NOx Emissions from Shipping in Real Operations," aims to establish more realistic emission levels and analyze the economic and environmental consequences of ships emitting more than expected.

Ship engines are classified into a Tier system from I to III, where Tier I engines have the highest and Tier III engines the lowest NOx emissions. However, measurements on Tier II ships can sometimes show higher emissions than both Tier I ships and non-regulated vessels during real-world operations. Additionally, measurements on Tier III ships often indicate high emissions, suggesting that emission control systems are not being used as intended.

The project's goal is to develop methods for calculating actual NOx emissions for individual ships. It will also contribute to the development of regulations for shipping's NOx emissions and improve procedures for managing after-treatment technologies. In the long term, the project aims to reduce NOx's negative impact on health and the environment.

The project is carried out in collaboration with Marine Benchmark, which is further developing its AIS model for calculating NOx emissions, and Chalmers University, which is responsible for emissions measurements and data collection. IVL’s focus in the project is to evaluate the environmental impact of emissions exceeding Tier levels and assess the external costs associated with this. The costs of reducing emissions to comply with the actual Tier levels will also be analyzed.