Recently, with increasing interest in environmental, human and social hazards caused by air pollution, regulations are being strengthened to prevent air pollution, and IMO is also working to reduce air pollutants from ships.
Efforts to reduce air pollutant emissions from ships include not only tightening regulations, but also countries and ports implementing incentives based on voluntary participation of ships, such as use of onshore power supply, vessel speed reduction or use of low sulfur fuel oil.
Recently, air pollutants generated from ships are attracting attention as a major cause of national air pollution as well as in ports and communities near the ports where ships enter and leave frequently. The "special act on air quality improvement, including port areas" was enacted and is expected to be implemented on January 1, 2020.
It is important to reinforce regulations of ships, but also I think it is necessary to study and review incentive system based on overseas cases.
This study examines international and regional air pollution regulations for NOx, SOx, GHG, PM, etc and national incentive systems. And examines changes in ship emissions through Vessel Speed Reduction among incentives to reduce air pollutants. The actual cases were examined and their impact was evaluated.
The ultimate goal of this study is to look at ways to minimize and effectively manage errors prior to decision making and enforcement of these management systems by focusing on emission reductions at vessel speed reduction.
First, the types of incentive schemes implemented by ports and their benefits were examined. Environmental Ship Index implemented by the International Association of ports and harbors applied to over 70 ports worldwide, Greenport Program in Singapore, Vessel Speed Reduction Program in various US ports, and Eco-ship in Panama.
For the sake of confirmation the effectiveness of VSR among several incentive schemes, the speed reduction operation of case vessels was conducted arbitrarily on the actual operating vessel, and the data was reviewed on a case-by-case basis. However, the case-by-case analysis was different. In the case of relatively short distances, it was not possible to confirm the change in fuel consumption according to the change of ship speed. On the other hand, in the case of relatively long distances, constant changes in fuel consumption and air pollutant emissions were observed while the ship speed was changing. In light of this, the actual effect of VSR needs to be measured over a distance of 20 nautical miles.
In addition, the ship's automatic identification system (AIS) data was obtained for vessels entering and leaving Busan port from February to May 2019 to examine the characteristics of each vessel. In order to analyze the air pollutant emission pattern, the fuel consumption was estimated and the emission was calculated when operating at the average speed of each ship type and reduced speed of the ship with Busan port data. As a result, the emission reduction efficiency according to the low speed operation of the ship was confirmed on the all vessels and the largest reduction effect in the container ship, and relatively small in the general cargo ship.
However, when the ship's speed reduction program is applied, the operation time is extended due to the limitation of the ship's speed. The results showed little change. This seems to be because the ship's emissions are compared with the estimated value proportionally, and therefore, it is necessary to collect and review the data of the actual operating ship.
In addition, it is necessary for the government who make the policy decision about the VSR management system to conduct vessel speed reduction at sufficient distance from the land in consideration of the results of this study.