Marine Pollution Mitigation by Waste Oils Recycling Onboard Ships: Technical Feasibility and Need for New Policy and Regulations

Abstract

About 80% of the total pollution from ships is caused by operational oil discharges into the sea, often made deliberately and in violation of international rules; the main reasons can be due to cost savings or lack of adequate facilities in ports to receive waste oils. Therefore, reducing waste oil discharges is crucial for a proper protection of the marine environment. In this regard, the paper presents the preliminary feasibility of a particular waste recycling technology, aimed at obtaining marine fuel oil from sludge, through a pyrolysis process to be carried out in a small reactor onboard. The originality of the research consists in the adaptation of pyrolysis to oily waste produced by ships, since this technology is traditionally applied to solid waste and biomass. Furthermore, the plant has to be designed for operation on board the ship, therefore under very different constraints compared to traditional land plants. Although the preliminary lab tests and simulation results in the chemical process are promising enough, there are still some technical criticalities due to the energy optimization of the reactor for an efficient use onboard of the whole system. In addition, the possibility of recycling waste, directly onboard ships, is not yet covered by mandatory regulations, which is why shipowners generally still feel unmotivated to invest in such technologies.

Considerations on Prevention of Pollution from Ships in a Seaport

“…The preliminary feasibility of a particular waste recycling technology [85] Pollution from ships-oil -Issues related to the identification and prevention of ship pollution, with special focus on oil pollution [86] -Issues related to pollution caused by oil spills into the sea, analyzing some major marine pollution incidents [87,88] -Various aspects of both land-and sea-based oil pollution [89] -Results of research based on a fact that over a million tons per year of oil is spilled from ships into the sea [90] -Adequacy level of the MARPOL convention implementation related to the pollution of the sea by oil from ships [91,92] Pollution from ships-solid and liquid waste -The marine pollution caused by marine domestic waste [93] -Issues related to the implementation of international regulations (mainly MARPOL convention) for the control of pollution of the sea with solid and liquid waste from ships [94][95][96][97] Pollution from ships-emissions -A fact that pollution from ships is not limited to the sea; it causes significant air and other forms of pollution [98] -The international regulations on ship emissions and their influence on level of SO 2 emissions from Ocean Going Vessels (OGVs) [99] -Summarizing studies that address air pollution, with special focus on particulate matter from marine vessels [100] -Pollution of air by large ships in the hub ports (taking into account that low-grade marine fuel oil contains 3500 times more sulfur than road diesel) [101] -Public health and climate impacts of low-sulfur fuels in global shipping [102] -The status of pollution mitigation measures implemented to date in the shipping sector [103] -The contributions of ship emissions of NO 2 , SO 2 , PM 10 , and PM 2.5 to air quality in the ports [104] -Annex VI (of the MARPOL convention) issues (influence of shipping industry on climate change) [105,106] -Initial strategy for the reduction in GHG emissions from ships in a port [107] -Air quality management in main Mediterranean ports [108] (Source: author).…”