Chemical Characterization of Exhaust Emissions from Selected Canadian Marine Vessels: The Case of Trace Metals and Lanthanoids

Abstract

This paper reports the chemical composition of exhaust emissions from the main engines of five ocean going cargo vessels, as they traveled in Canadian waters. The emission factors (EFs) of PM2.5 and SO2 for vessels tested on various intermediate fuel oils (IFO), ranged from 0.4 to 2.2 g kW(-1) hr(-1) and 4.7 to 10.3 g kW(-1) hr(-1), respectively, and were mainly dependent on the content of sulfur in the fuel. Average NOx, CO, and CO2 EFs for these tests were 12.7, 0.45, and 618 g kW(-1) hr(-1), respectively and were generally below benchmark values commonly used by regulatory agencies. The composition of PM2.5 was dominated by hydrated sulfates, organic carbon and trace metals which accounted for 80-97% of total PM2.5 mass. A substantial decrease of measured emission factors for PM2.5 and SO2 was observed when the fuel was changed from IFO to marine diesel oil (MDO), in one of the tested vessels. The main component of PM2.5 in this case was organic carbon accounting for 65% of PM2.5 mass. In addition to commonly reported pollutants, this study presents EFs of the lanthanoid elements and showed that their distribution patterns in ship-exhaust PM2.5 were very similar to the PM2.5 emitted by oil refining facilities. Hence, using La:Ce:V tertiary diagrams and La/V ratios is necessary to distinguish ship plumes from primary emissions related to accidental and/or routine operation of oil-refining industry.

Characteristics of marine shipping emissions at berth: profiles for particulate matter and volatile organic compounds

“…Another crucial piece of evidence is the elemental analysis of three diesel samples collected during field measurements (shown in Table 4). Vanadium was not detected in any of the three diesel samples, which was significantly different from the data from previous studies (38.0-133.8 mg kg −1 ; Celo et al, 2015) using intermediate fuel oils (IFO) ( Table 4). Regarding vanadium "sources", it can be inferred that if the content of vanadium in fuel keeps declining, the role it plays as a tracer will not be as significant as it has been; furthermore, it will be much harder to detect the existence of vanadium in ambient atmosphere.…”

“…According to Sippula et al's (2014) research on marine diesel engines, Na can also exist in lubrication oil and be exhausted along with the lubrication and grinding process. It is widely recognized that the metal content existent in exhausted particles has a strong correlation with that in fuel (Celo et al, 2015;Moldanová et al, 2013). Although the content of Na is obviously lower than that of vanadium (55-133.8 mg kg −1 ), the peaks of Na + in ion mass spectra are mostly higher than the peaks of the V + / VO + signal.…”

“…V + and its oxidized ion VO + were considered to be symbolic of ship exhaust, as V exists in fuels such as heavy fuel oils (HFO). Previous studies (Celo et al, 2015;Liu et al, 2017) have frequently used V + and VO + to identify particles from ship exhausts, although they are observed more rarely than other large quantity particles. Other metallic ions such as Fe + and Cu + were also observed and had quite a small relative intensity, due to the fact that metal elements scarcely exist in the atmosphere and fuels combust in powertrain systems.…”

“…8. Owing to the fact that vanadium is a typical metallic element mostly found in heavy fuel oil with a higher sulfur content than distillate fuels (Moldanová et al, 2009;Celo et al, 2015), when obvious vanadium signals occurred in the ion mass spectra of particles from Ship 13 and Ship 17 they were very likely due to the use of heavy fuel oils at berth. Accordingly, the sulfur intensity also had the potential be very high.…”

First long-term and near real-time measurement of trace elements in China's urban atmosphere: temporal variability, source apportionment and precipitation effect

“…1). Gathering evidence revealed that the ratio of V / Ni can serve as a robust indicator of shipping emissions (Tao et al, 2013;Celo et al, 2015;Liu et al, 2017;Viana et al, 2009). A recent study in Shanghai port suggested that the ratio of V / Ni in aerosols emitted from heavy oil combustion of ocean-going ship engines was 3.4 on average (Zhao et al, 2013).…”