TY - RPRT
TI - Evaluation of a Modern Tier 2 Ocean Going Vessel on Two Low Sulfur Fuels
AU - Johnson, K
AU - Miller, W
AU - McCaffrey, C
AU - Zhu, H
AB - Emissions from marine engines (container vessels, crude tankers, bulk cargo, auto carrier, cruise ships, and other ocean-going vessels (OGV)) represent a significant contribution of particulate matter (PM), sulfur oxide (SOx) and nitrogen oxide (NOx) emissions. Global shipping represents over 80% of the volume and 70% of the value of goods transported, thus shipping is a major contributor to our global emissions inventory. To control SOx emissions from marine engines, International Maritime Organization’s (IMO) Annex VI regulations include caps on the sulfur content of fuel oil which indirectly also reduces PM emissions. Providing the vessel meets the applicable sulfur limit, heavy fuel oil (HFO) is allowed by IMO if alternative technology is used to limit SOx emissions to a fuel equivalent 0.1% sulfur (S). Ultra-low sulfur residual fuel oil (ULSFO) is available in lieu of high cost low sulfur distillate Marine Gas Oil (MGO). To minimize PM and NOx emissions further, the California Air Resources Board (CARB) requires OGV to use distillate fuels within 24 nautical miles of California coastline. The CARB fuel rule, thus, prevents OGV from operating with low sulfur residual fuels and high sulfur fuels combined with scrubbers. The objective of this work is to study the in-use emissions from a modern OGV while switching from a California approved distillate low sulfur fuel to a commercially available IMO approved ultra-low sulfur residual fuel. In this study a ULSFO fuel (0.089% sulfur) was compared to a low sulfur compliant MGO fuel (0.038% sulfur). This report presents an evaluation of the emissions comparison between these two fuels. The evaluation was performed on a slow speed diesel main engine (ME), a medium speed auxiliary engine (AE), and an auxiliary boiler housed in a 13,000 TEU container vessel. The test methods utilized ISO 8178 E3 and D2 steady state test cycles to determine the emissions rate of gaseous and particulate pollutants for the ME and the AE, respectively. The auxiliary boiler was evaluated at 60% of maximum capacity. The emissions measured were regulated gaseous, PM2.5 mass emissions, and PM composition which included elemental carbon PM, organic carbon PM, and sulfate PM. Additional speciated toxics, aldehydes and ketones, and trace metals were analyzed for the auxiliary boiler. Other methods and practices, such as dry to wet correction and NOx humidity correction, followed ISO and CFR recommendations. The brake specific fuel consumption and carbon dioxide emissions were in good agreement with other large marine engine results suggesting the tests were performed well and were representative of a properly operated vessel. The estimated ISO weighted NOx emissions were at the certification limit for the ME and below the certification limit for the AE. The emissions of the ME at slow speed maneuvering were 27.4 g/kWhr and 16.9 g/kWhr at cruise speed with a weighted emission of 21.29 g/kWhr for the MGO fuel. The ULSFO fuel showed higher NOx emissions than the MGO fuel for the ME, AE and auxiliary boiler, but the differences were not statistically significant except for the auxiliary boiler. The weighted ME PM2.5 for the MGO fuel were 0.219 g/kWhr and 0.295 g/kWhr for the ULSFO fuel, suggesting the ULSFO fuel was 35% higher PM2.5 emissions than the MGO fuel. A paired t-test suggest the mean difference between the fuels were statistically significant. The higher ULSFO PM2.5 emissions appears to be a result of higher organic carbon PM and elemental carbon PM. The AE and auxiliary boiler PM2.5 emissions also varied between the sources where the ULSFO fuel was higher by 55% for the AE and 48% lower for the auxiliary boiler, but these differences were not statistically significant based on a paired t-test. The organic carbon PM for the ULSFO fuel was higher by 90% compared to the MGO fuel and was statistical significant according to the t-test. The equivalent black carbon emissions (eBC) were low for all the sources and ranged from 0.4 mg/kWhr to 3 mg/kWhr to 0.02 g/kg-fuel for the ME, AE, and auxiliary boiler, respectively.
DA - 2019/03//
PY - 2019
SP - 103
PB - University of California Riverside
UR - https://www.sciencedirect.com/science/article/pii/S0016236118318398
LA - English
KW - Unspecified Feedstock
KW - Heavy Fuel Oil (HFO)
KW - Marine Gas Oil (MGO)
KW - Unspecified Pathway
KW - Engine Testing and Performance
KW - Lifecycle Assessment (LCA) and Air Emissions
KW - Ocean-going Vessels
ER -