Real-world emissions of inland ships on the Grand Canal, China

- Distance-based and fuel-based emission factors of gaseous and PM from 7 inland ships were measured using PEMS.
- Average distance-based emission factors of CO, HC and PM for manoeuvring mode are higher than those for cruise mode.
- NOx in this study is nearly twice of estimated Tier 1 standard limit (in unit of g kg−1 fuel).
- Distance-based emission factors of four pollutants are higher with the increase of engine loads.

Ship emissions are widely recognized as a relevant source of the total air pollution and have a remarkable impact on air quality of the sea, territorial waters and coastal areas. To assess this impact, various emission models have been developed to calculate the emission inventory of ship based on ship activity data. However, few studies in China have collected the emission factors of local ship which are decisive factors in accurate assessment of ship emission inventory. This study intends to obtain emission data of inland ships on the Grand Canal of China by conducting on-board emission tests. We measured CO, HC NOx and PM emission from 7 inland ships of different engine powers, and derive distance-based and fuel-based emission factors on the basis of the cruise and manoeuvring (including port departure and port arrival) operating modes. The results show that average distance-based emission factors of CO, HC and PM for manoeuvring mode are higher than those for cruise mode. For NOx, average distance-based emission factors for cruise mode are higher than those for port arrival mode but lower than those for port departure mode. Particular number (PN) distribution analysis indicates that larger amounts of small size PM (Dp < 0.01 μm) appeared on manoeuvring mode, which can affect regional air quality and human health. The average fuel-based emission factor of NOx in this study is 1.4-4.3 times higher than those in on-board studies. When compared with estimated Tier 1 standard limit (in unit of g kg−1 fuel), NOx in this study is nearly twice of Tier 1. The higher NOx emission indicates that stricter emission strategies and policies should be implemented to control ship emission in China. It is noticeable that distance-based emission factors of four pollutants are higher with the increase of engine loads.