Effects of the Carbon Intensity Index Rating System on the Development of the Northeast Passage

• Published in: Journal of Marine Science and Engineering
• Main Authors: Yuh-Ming Tsai, Cherng-Yuan Lin
• Format: Text
• Language: English
• Published: Multidisciplinary Digital Publishing Institute 2023
• Subjects: Northeast Passage; CII rating; carbon intensity index; greenhouse gas; marine engine emission
• Online Access: https://doi.org/10.3390/jmse11071341

For many years, the Suez Canal (also known as the Suez Route) has been the main route connecting Europe and Asia. However, compared with the Suez Route, the Northeast Passage could save up to 41% of the journey. The ship carbon intensity index (CII) rating system of the International Maritime Organization (IMO) came into effect in 2023. This study took an existing bulk carrier on the Europe–Asia route as an example to calculate the attained CII values at different sailing speeds. It was found that, regardless of external factors, when the ship speed dropped from 14.4 knots (85% maximum continuous rating (MCR)) to 12.6 knots (55% MCR), the corresponding attained CII value decreased from 6.48 g/ton·nm to 5.19 g/ton·nm. Therefore, sailing speed was the key factor influencing the attained CII value, and it was independent of the shipping distance. In addition, when the ship’s sailing output power was between 85% MCR and 75% MCR, for every 5% decrease in MCR, its attained CII value would decrease by 0.13 g/ton·nm, and the fuel consumption amount would decrease by 1 ton/day. However, when the ship sailed at an output power of 75% MCR to 55% MCR, for every 5% decrease in MCR, the attained CII value would decrease even more, up to 0.26 g/ton·nm. In addition, the attained CII value would be reduced by up to 100% and fuel consumption amount would be reduced by up to 1.5 ton/day, resulting in a 50% fuel saving effect. Therefore, to obtain a better CII rating, the optimal ship speed should be set between 75% MCR and 55% MCR according to the wave and wind strengths. However, although slow-speed sailing is the most efficient factor, the number of sailing days would also be extended. Through the ratio created by dividing the distance of the Northeast Passage by the Suez Route, whether the Northeast Passage has the benefit of balancing shipping schedules could be judged. The outcome indicated that a ratio lower than 1 would result in a more balanced shipping schedule. Compared with 2019, the number of ships sailing through the ...