Air emissions from marine vessels account for 5 to 10% of global emissions from the transport sector.
The basic components of atmospheric emissions are carbon, sulphur and nitrogen oxides formed during the combustion of fuel in ship engines.
The decrease in CO2 emissions is due to the increase in the use of LNG fuel in 2020 to 16% of the total fuel consumption of the fleet, which generally boosts the energy efficiency of ships.
Although the share of LNG fuel in the total fuel consumption of the fleet increased in 2020, this did not lead to a reduction in nitrogen oxides emissions because their amount largely depends on the engines’ running time and operating load.
The significant reduction in sulphur oxides emissions in 2020 is a result of activities carried out in 2019 on all the Group’s ships to prepare for the switch to low-sulphur marine fuel with a sulphur content not exceeding 0.5% from 1 January 2020.
Energy Efficiency Operational Index (EEOI) is calculated as the total CO2 emissions (in grammes) produced on a voyage per total tonne-miles generated (tonnes carried multiplied by distance travelled).
The table below shows the EEOI calculation for different types of Sovcomflot Group’s vessels operating on voyage (spot) contracts. In this case, fuel for the vessels is procured by the ship owner or fleet operator. A decrease in the EEOI index means a decrease in carbon oxides emissions and, accordingly, in fuel consumption per tonne-mile, which characterises an improvement in the operational performance of the Company’s fleet.
|Type of vessel||Standard||Actual 2020||Actual 2019|
|Suezmax tankers||≤ 12||8.138||8.346|
|Aframax tankers||≤ 15||5.668||10.118|
|LR II product carriers||≤ 15||8.122||11.053|
|LR I product carriers||≤ 16||14.553||13.294|
|MR product carriers||≤ 25||17.207||19.617|
|Handy product carriers||≤ 25||20.575||24.809|
|Panamax bulkers||≤ 12||10.307||7.580|
The carbon intensity targets under SCF Group’s ‘Green Charter’ are based on the vision of the International Maritime Organization (IMO). In 2018 the IMO adopted a decarbonisation strategy, which defines CO2 emission reduction targetв. The IMO expects global carbon dioxide emissions to be reduced by at least 50% by 2050 compared to 2008 and CO2 emissions per transport work (CO2 emission intensity index) to be reduced by at least 40% by 2030 and 70% by 2050 compared to 2008 levels.
Results of the use of LNG as a fuel for Aframax tankers
The commissioning of a series of SCF’s new generation vessels, the world’s first Aframax tankers specially designed to run on LNG, has significantly contributed to environmental protection. The tankers of this series have dual-fuel main and auxiliary engines and boilers. These vessels are fitted with Selective Catalytic Reduction technology, which enables compliance with Tier III regulations governing NOx emissions (Annex VI to the International Convention for the Prevention of Pollution from Ships) even when running on diesel fuel.
The first vessel of the series was put into operation in 2018. By the end of 2019 the number of Aframax tankers in the SCF fleet capable of running on LNG increased to six. An analysis of data obtained from ship operations during 2018-2020 confirms the theoretical calculations that Sovcomflot relied on when assessing the prospects of this technology.
The diagram below shows the amount of carbon dioxide emissions from SCF Group’s Aframax tankers that use LNG along with other marine fuels compared with similar tankers running on diesel fuel.
Provided that an Aframax tanker runs exclusively on LNG, the reduction of sulphur oxides and soot emissions reaches 100%, nitrogen oxides emissions decrease by at least 76%, and the reduction of carbon dioxide emissions can reach 30% as compared with power plants running on conventional heavy fuel.