Marine Fuel Regulations and Engine Emissions: Impacts on Physicochemical Properties, Cloud Activity and Emission Factors
Journal article, 2024

Marine regulations aim to reduce sulfur and nitrogen exhaust emissions from maritime shipping. Here, two compliance pathways for reducing sulfur dioxide emissions, fuel sulfur content reduction and exhaust wet scrubbing, are studied for their effects on physicochemical properties and cloud forming abilities of engine exhaust particles. A test-bed diesel engine was utilized to study fresh exhaust emissions from combustion of non-compliant, high sulfur content fuel with (WS) and without (HiS) the usage of a wet scrubber as well as a regulatory compliant, low sulfur content fuel (LoS). Particle number emissions are decreased by ≈99% when switching to LoS due to absence of 20–30 nm sulfate rich particles. While number emissions for WS are also decreased, a shift in the sulfate mode toward larger sizes was found to increase particle mass emission factors by at least 31%. Changes in the mixing state induced by the compliance measures are reflected in the hygroscopicity of the exhaust particles. Fuel sulfur reduction decreased cloud condensation nuclei emissions by at least 97% due to emissions of primarily hydrophobic soot particles. Wet scrubbing increased those emissions, mainly driven by changes in particle size distributions. Our results indicate that both compliance alternatives have no obvious impact on the ice forming abilities of 200 nm exhaust particles. These detailed results are relevant for atmospheric processes and might be useful input parameters for cloud-resolving models to investigate ship aerosol-cloud interactions and to quantify the impact of shipping on radiative budgets from local to global scales.

hygroscopicity

CCN

aerosol

ice nucleation

cloud

ship emissions

Author

Luis F.E.d. Santos

University of Gothenburg

Kent Salo

Chalmers, Mechanics and Maritime Sciences (M2), Maritime Studies

X. Kong

University of Gothenburg

M. Hartmann

University of Gothenburg

Leibniz Institute for Tropospheric Research

Jonas Sjöblom

Chalmers, Mechanics and Maritime Sciences (M2), Energy Conversion and Propulsion Systems

Erik S Thomson

University of Gothenburg

Journal of Geophysical Research: Atmospheres

2169897X (ISSN) 21698996 (eISSN)

Vol. 129 5 e2023JD040389

Human influence on Nordic and Arctic Climate and Air: shipping, mixed-phase clouds, and particles

Formas (2017-00564), 2018-01-01 -- 2020-12-31.

Subject Categories

Meteorology and Atmospheric Sciences

DOI

10.1029/2023JD040389

More information

Latest update

3/15/2024