Size‐resolved particle emission factors for individual ships
Artikel i vetenskaplig tidskrift, 2011
In these experiments size‐resolved emission factors for particle number (EFPN) and mass (EFPM) have been determined for 734 individual ship passages for real‐world dilution. The method used is an extractive sampling method of the passing ship plumes where particle number/mass and CO2 were measured with high time resolution (1 Hz). The measurements were conducted on a small island located in the entrance to the port of Gothenburg (N57.6849, E11.838), the largest harbor in Scandinavia. This is an emission control area (ECA) and in close vicinity to populated areas. The average EFPN and EFPM were 2.55 ± 0.11 × 1016 (kg fuel)−1 and 2050 ± 110 mg (kg fuel)−1, respectively. The determined EF for ships with multiple passages showed a great reproducibility. Size‐resolved EFPN were peaking at small particle sizes ∼35 nm. Smaller particle sizes and hence less mass were observed by a gas turbine equipped ship compared to diesel engine equipped ships. On average 36 to 46% of the emitted particles by number were non‐volatile and 24% by mass (EFPN 1.16 ± 0.19 × 1016 [kg fuel]−1 and EFPM 488 ± 73 mg [kg fuel]−1, respectively). This study shows a great potential to gain large data‐sets regarding ship emission determining parameters that can improve current dispersion modeling for health assessments on local and regional scales. The global contributions of total and non‐volatile particle mass from shipping using this extensive data‐set from an ECA were estimated to be at least 0.80 Tgy−1 and 0.19 Tgy−1.
Successfully providing 734 real world diluted size‐resolved emission factors