Adapting land-based emission control strategies for marine environments: a framework for reducing ultrafine particles from ship engines

This study investigates the possibility of applying Ultra-Fine Filtration (UFF) technology, which has been applied to land-based (LB) diesel engines, to marine diesel engines. The test, inspired by the increasingly stringent International Maritime Organization (IMO) MARPOL Annex VI regulations, assesses the performance of UFF using a bench-scale engine (John Deere PowerTech 4045H) in three operating conditions: idle, 2100 RPM (unloaded) and 2100 RPM (loaded). These conditions show a resemblance to such important marine operational modes as port maneuvering, low-load auxiliary operation and cruising. The findings reveal that UFF systems were able to reduce overall Particulate Matter (PM) concentration (44 mg/m3 to 13 mg/m3) by up to 70% and the level of smoke was significantly lowered in all of the test conditions. Nonetheless, the emissions of nitrogen oxides (NOx) increased (up to 40%), which can be explained by the fact that the combustion was more complete and the in-cylinder temperatures were higher. The results indicate that, although UFF is highly efficient at controlling PM, it needs to be combined with other after-treatment processes, such as Selective Catalytic Reduction (SCR), to control all emissions. This paper provides background on the transfer of UFF systems to the maritime industry.